David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1 | #!/usr/bin/env python |
| 2 | |
| 3 | # Copyright 2016, The Android Open Source Project |
| 4 | # |
David Zeuthen | c612e2e | 2016-09-16 16:44:08 -0400 | [diff] [blame] | 5 | # Permission is hereby granted, free of charge, to any person |
| 6 | # obtaining a copy of this software and associated documentation |
| 7 | # files (the "Software"), to deal in the Software without |
| 8 | # restriction, including without limitation the rights to use, copy, |
| 9 | # modify, merge, publish, distribute, sublicense, and/or sell copies |
| 10 | # of the Software, and to permit persons to whom the Software is |
| 11 | # furnished to do so, subject to the following conditions: |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 12 | # |
David Zeuthen | c612e2e | 2016-09-16 16:44:08 -0400 | [diff] [blame] | 13 | # The above copyright notice and this permission notice shall be |
| 14 | # included in all copies or substantial portions of the Software. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 15 | # |
David Zeuthen | c612e2e | 2016-09-16 16:44:08 -0400 | [diff] [blame] | 16 | # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 17 | # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 18 | # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 19 | # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| 20 | # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| 21 | # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| 22 | # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 23 | # SOFTWARE. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 24 | # |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 25 | """Command-line tool for working with Android Verified Boot images.""" |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 26 | |
| 27 | import argparse |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 28 | import binascii |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 29 | import bisect |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 30 | import hashlib |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 31 | import math |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 32 | import os |
| 33 | import struct |
| 34 | import subprocess |
| 35 | import sys |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 36 | import tempfile |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 37 | import time |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 38 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 39 | # Keep in sync with libavb/avb_version.h. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 40 | AVB_VERSION_MAJOR = 1 |
| 41 | AVB_VERSION_MINOR = 0 |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 42 | AVB_VERSION_SUB = 0 |
| 43 | |
David Zeuthen | 5830552 | 2017-01-11 17:42:47 -0500 | [diff] [blame] | 44 | AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED = 1 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 45 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 46 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 47 | class AvbError(Exception): |
| 48 | """Application-specific errors. |
| 49 | |
| 50 | These errors represent issues for which a stack-trace should not be |
| 51 | presented. |
| 52 | |
| 53 | Attributes: |
| 54 | message: Error message. |
| 55 | """ |
| 56 | |
| 57 | def __init__(self, message): |
| 58 | Exception.__init__(self, message) |
| 59 | |
| 60 | |
| 61 | class Algorithm(object): |
| 62 | """Contains details about an algorithm. |
| 63 | |
| 64 | See the avb_vbmeta_header.h file for more details about |
| 65 | algorithms. |
| 66 | |
| 67 | The constant |ALGORITHMS| is a dictionary from human-readable |
| 68 | names (e.g 'SHA256_RSA2048') to instances of this class. |
| 69 | |
| 70 | Attributes: |
| 71 | algorithm_type: Integer code corresponding to |AvbAlgorithmType|. |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 72 | hash_name: Empty or a name from |hashlib.algorithms|. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 73 | hash_num_bytes: Number of bytes used to store the hash. |
| 74 | signature_num_bytes: Number of bytes used to store the signature. |
| 75 | public_key_num_bytes: Number of bytes used to store the public key. |
| 76 | padding: Padding used for signature, if any. |
| 77 | """ |
| 78 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 79 | def __init__(self, algorithm_type, hash_name, hash_num_bytes, |
| 80 | signature_num_bytes, public_key_num_bytes, padding): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 81 | self.algorithm_type = algorithm_type |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 82 | self.hash_name = hash_name |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 83 | self.hash_num_bytes = hash_num_bytes |
| 84 | self.signature_num_bytes = signature_num_bytes |
| 85 | self.public_key_num_bytes = public_key_num_bytes |
| 86 | self.padding = padding |
| 87 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 88 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 89 | # This must be kept in sync with the avb_crypto.h file. |
| 90 | # |
| 91 | # The PKC1-v1.5 padding is a blob of binary DER of ASN.1 and is |
| 92 | # obtained from section 5.2.2 of RFC 4880. |
| 93 | ALGORITHMS = { |
| 94 | 'NONE': Algorithm( |
| 95 | algorithm_type=0, # AVB_ALGORITHM_TYPE_NONE |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 96 | hash_name='', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 97 | hash_num_bytes=0, |
| 98 | signature_num_bytes=0, |
| 99 | public_key_num_bytes=0, |
| 100 | padding=[]), |
| 101 | 'SHA256_RSA2048': Algorithm( |
| 102 | algorithm_type=1, # AVB_ALGORITHM_TYPE_SHA256_RSA2048 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 103 | hash_name='sha256', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 104 | hash_num_bytes=32, |
| 105 | signature_num_bytes=256, |
| 106 | public_key_num_bytes=8 + 2*2048/8, |
| 107 | padding=[ |
| 108 | # PKCS1-v1_5 padding |
| 109 | 0x00, 0x01] + [0xff]*202 + [0x00] + [ |
| 110 | # ASN.1 header |
| 111 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 112 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 113 | 0x00, 0x04, 0x20, |
| 114 | ]), |
| 115 | 'SHA256_RSA4096': Algorithm( |
| 116 | algorithm_type=2, # AVB_ALGORITHM_TYPE_SHA256_RSA4096 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 117 | hash_name='sha256', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 118 | hash_num_bytes=32, |
| 119 | signature_num_bytes=512, |
| 120 | public_key_num_bytes=8 + 2*4096/8, |
| 121 | padding=[ |
| 122 | # PKCS1-v1_5 padding |
| 123 | 0x00, 0x01] + [0xff]*458 + [0x00] + [ |
| 124 | # ASN.1 header |
| 125 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 126 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 127 | 0x00, 0x04, 0x20, |
| 128 | ]), |
| 129 | 'SHA256_RSA8192': Algorithm( |
| 130 | algorithm_type=3, # AVB_ALGORITHM_TYPE_SHA256_RSA8192 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 131 | hash_name='sha256', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 132 | hash_num_bytes=32, |
| 133 | signature_num_bytes=1024, |
| 134 | public_key_num_bytes=8 + 2*8192/8, |
| 135 | padding=[ |
| 136 | # PKCS1-v1_5 padding |
| 137 | 0x00, 0x01] + [0xff]*970 + [0x00] + [ |
| 138 | # ASN.1 header |
| 139 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 140 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 141 | 0x00, 0x04, 0x20, |
| 142 | ]), |
| 143 | 'SHA512_RSA2048': Algorithm( |
| 144 | algorithm_type=4, # AVB_ALGORITHM_TYPE_SHA512_RSA2048 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 145 | hash_name='sha512', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 146 | hash_num_bytes=64, |
| 147 | signature_num_bytes=256, |
| 148 | public_key_num_bytes=8 + 2*2048/8, |
| 149 | padding=[ |
| 150 | # PKCS1-v1_5 padding |
| 151 | 0x00, 0x01] + [0xff]*170 + [0x00] + [ |
| 152 | # ASN.1 header |
| 153 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 154 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 155 | 0x00, 0x04, 0x40 |
| 156 | ]), |
| 157 | 'SHA512_RSA4096': Algorithm( |
| 158 | algorithm_type=5, # AVB_ALGORITHM_TYPE_SHA512_RSA4096 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 159 | hash_name='sha512', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 160 | hash_num_bytes=64, |
| 161 | signature_num_bytes=512, |
| 162 | public_key_num_bytes=8 + 2*4096/8, |
| 163 | padding=[ |
| 164 | # PKCS1-v1_5 padding |
| 165 | 0x00, 0x01] + [0xff]*426 + [0x00] + [ |
| 166 | # ASN.1 header |
| 167 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 168 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 169 | 0x00, 0x04, 0x40 |
| 170 | ]), |
| 171 | 'SHA512_RSA8192': Algorithm( |
| 172 | algorithm_type=6, # AVB_ALGORITHM_TYPE_SHA512_RSA8192 |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 173 | hash_name='sha512', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 174 | hash_num_bytes=64, |
| 175 | signature_num_bytes=1024, |
| 176 | public_key_num_bytes=8 + 2*8192/8, |
| 177 | padding=[ |
| 178 | # PKCS1-v1_5 padding |
| 179 | 0x00, 0x01] + [0xff]*938 + [0x00] + [ |
| 180 | # ASN.1 header |
| 181 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 182 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 183 | 0x00, 0x04, 0x40 |
| 184 | ]), |
| 185 | } |
| 186 | |
| 187 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 188 | def get_release_string(): |
| 189 | """Calculates the release string to use in the VBMeta struct.""" |
| 190 | # Keep in sync with libavb/avb_version.c:avb_version_string(). |
| 191 | return 'avbtool {}.{}.{}'.format(AVB_VERSION_MAJOR, |
| 192 | AVB_VERSION_MINOR, |
| 193 | AVB_VERSION_SUB) |
| 194 | |
| 195 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 196 | def round_to_multiple(number, size): |
| 197 | """Rounds a number up to nearest multiple of another number. |
| 198 | |
| 199 | Args: |
| 200 | number: The number to round up. |
| 201 | size: The multiple to round up to. |
| 202 | |
| 203 | Returns: |
| 204 | If |number| is a multiple of |size|, returns |number|, otherwise |
| 205 | returns |number| + |size|. |
| 206 | """ |
| 207 | remainder = number % size |
| 208 | if remainder == 0: |
| 209 | return number |
| 210 | return number + size - remainder |
| 211 | |
| 212 | |
| 213 | def round_to_pow2(number): |
| 214 | """Rounds a number up to the next power of 2. |
| 215 | |
| 216 | Args: |
| 217 | number: The number to round up. |
| 218 | |
| 219 | Returns: |
| 220 | If |number| is already a power of 2 then |number| is |
| 221 | returned. Otherwise the smallest power of 2 greater than |number| |
| 222 | is returned. |
| 223 | """ |
| 224 | return 2**((number - 1).bit_length()) |
| 225 | |
| 226 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 227 | def encode_long(num_bits, value): |
| 228 | """Encodes a long to a bytearray() using a given amount of bits. |
| 229 | |
| 230 | This number is written big-endian, e.g. with the most significant |
| 231 | bit first. |
| 232 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 233 | This is the reverse of decode_long(). |
| 234 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 235 | Arguments: |
| 236 | num_bits: The number of bits to write, e.g. 2048. |
| 237 | value: The value to write. |
| 238 | |
| 239 | Returns: |
| 240 | A bytearray() with the encoded long. |
| 241 | """ |
| 242 | ret = bytearray() |
| 243 | for bit_pos in range(num_bits, 0, -8): |
| 244 | octet = (value >> (bit_pos - 8)) & 0xff |
| 245 | ret.extend(struct.pack('!B', octet)) |
| 246 | return ret |
| 247 | |
| 248 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 249 | def decode_long(blob): |
| 250 | """Decodes a long from a bytearray() using a given amount of bits. |
| 251 | |
| 252 | This number is expected to be in big-endian, e.g. with the most |
| 253 | significant bit first. |
| 254 | |
| 255 | This is the reverse of encode_long(). |
| 256 | |
| 257 | Arguments: |
| 258 | value: A bytearray() with the encoded long. |
| 259 | |
| 260 | Returns: |
| 261 | The decoded value. |
| 262 | """ |
| 263 | ret = 0 |
| 264 | for b in bytearray(blob): |
| 265 | ret *= 256 |
| 266 | ret += b |
| 267 | return ret |
| 268 | |
| 269 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 270 | def egcd(a, b): |
| 271 | """Calculate greatest common divisor of two numbers. |
| 272 | |
| 273 | This implementation uses a recursive version of the extended |
| 274 | Euclidian algorithm. |
| 275 | |
| 276 | Arguments: |
| 277 | a: First number. |
| 278 | b: Second number. |
| 279 | |
| 280 | Returns: |
| 281 | A tuple (gcd, x, y) that where |gcd| is the greatest common |
| 282 | divisor of |a| and |b| and |a|*|x| + |b|*|y| = |gcd|. |
| 283 | """ |
| 284 | if a == 0: |
| 285 | return (b, 0, 1) |
| 286 | else: |
| 287 | g, y, x = egcd(b % a, a) |
| 288 | return (g, x - (b // a) * y, y) |
| 289 | |
| 290 | |
| 291 | def modinv(a, m): |
| 292 | """Calculate modular multiplicative inverse of |a| modulo |m|. |
| 293 | |
| 294 | This calculates the number |x| such that |a| * |x| == 1 (modulo |
| 295 | |m|). This number only exists if |a| and |m| are co-prime - |None| |
| 296 | is returned if this isn't true. |
| 297 | |
| 298 | Arguments: |
| 299 | a: The number to calculate a modular inverse of. |
| 300 | m: The modulo to use. |
| 301 | |
| 302 | Returns: |
| 303 | The modular multiplicative inverse of |a| and |m| or |None| if |
| 304 | these numbers are not co-prime. |
| 305 | """ |
| 306 | gcd, x, _ = egcd(a, m) |
| 307 | if gcd != 1: |
| 308 | return None # modular inverse does not exist |
| 309 | else: |
| 310 | return x % m |
| 311 | |
| 312 | |
| 313 | def parse_number(string): |
| 314 | """Parse a string as a number. |
| 315 | |
| 316 | This is just a short-hand for int(string, 0) suitable for use in the |
| 317 | |type| parameter of |ArgumentParser|'s add_argument() function. An |
| 318 | improvement to just using type=int is that this function supports |
| 319 | numbers in other bases, e.g. "0x1234". |
| 320 | |
| 321 | Arguments: |
| 322 | string: The string to parse. |
| 323 | |
| 324 | Returns: |
| 325 | The parsed integer. |
| 326 | |
| 327 | Raises: |
| 328 | ValueError: If the number could not be parsed. |
| 329 | """ |
| 330 | return int(string, 0) |
| 331 | |
| 332 | |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 333 | class RSAPublicKey(object): |
| 334 | """Data structure used for a RSA public key. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 335 | |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 336 | Attributes: |
| 337 | exponent: The key exponent. |
| 338 | modulus: The key modulus. |
| 339 | num_bits: The key size. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 340 | """ |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 341 | |
| 342 | MODULUS_PREFIX = 'modulus=' |
| 343 | |
| 344 | def __init__(self, key_path): |
| 345 | """Loads and parses an RSA key from either a private or public key file. |
| 346 | |
| 347 | Arguments: |
| 348 | key_path: The path to a key file. |
| 349 | """ |
| 350 | # We used to have something as simple as this: |
| 351 | # |
| 352 | # key = Crypto.PublicKey.RSA.importKey(open(key_path).read()) |
| 353 | # self.exponent = key.e |
| 354 | # self.modulus = key.n |
| 355 | # self.num_bits = key.size() + 1 |
| 356 | # |
| 357 | # but unfortunately PyCrypto is not available in the builder. So |
| 358 | # instead just parse openssl(1) output to get this |
| 359 | # information. It's ugly but... |
| 360 | args = ['openssl', 'rsa', '-in', key_path, '-modulus', '-noout'] |
| 361 | p = subprocess.Popen(args, |
| 362 | stdin=subprocess.PIPE, |
| 363 | stdout=subprocess.PIPE, |
| 364 | stderr=subprocess.PIPE) |
| 365 | (pout, perr) = p.communicate() |
| 366 | if p.wait() != 0: |
| 367 | # Could be just a public key is passed, try that. |
| 368 | args.append('-pubin') |
| 369 | p = subprocess.Popen(args, |
| 370 | stdin=subprocess.PIPE, |
| 371 | stdout=subprocess.PIPE, |
| 372 | stderr=subprocess.PIPE) |
| 373 | (pout, perr) = p.communicate() |
| 374 | if p.wait() != 0: |
| 375 | raise AvbError('Error getting public key: {}'.format(perr)) |
| 376 | |
| 377 | if not pout.lower().startswith(self.MODULUS_PREFIX): |
| 378 | raise AvbError('Unexpected modulus output') |
| 379 | |
| 380 | modulus_hexstr = pout[len(self.MODULUS_PREFIX):] |
| 381 | |
| 382 | # The exponent is assumed to always be 65537 and the number of |
| 383 | # bits can be derived from the modulus by rounding up to the |
| 384 | # nearest power of 2. |
| 385 | self.modulus = int(modulus_hexstr, 16) |
| 386 | self.num_bits = round_to_pow2(int(math.ceil(math.log(self.modulus, 2)))) |
| 387 | self.exponent = 65537 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 388 | |
| 389 | |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 390 | def encode_rsa_key(key_path): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 391 | """Encodes a public RSA key in |AvbRSAPublicKeyHeader| format. |
| 392 | |
| 393 | This creates a |AvbRSAPublicKeyHeader| as well as the two large |
| 394 | numbers (|key_num_bits| bits long) following it. |
| 395 | |
| 396 | Arguments: |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 397 | key_path: The path to a key file. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 398 | |
| 399 | Returns: |
| 400 | A bytearray() with the |AvbRSAPublicKeyHeader|. |
| 401 | """ |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 402 | key = RSAPublicKey(key_path) |
| 403 | if key.exponent != 65537: |
| 404 | raise AvbError('Only RSA keys with exponent 65537 are supported.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 405 | ret = bytearray() |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 406 | # Calculate n0inv = -1/n[0] (mod 2^32) |
| 407 | b = 2L**32 |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 408 | n0inv = b - modinv(key.modulus, b) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 409 | # Calculate rr = r^2 (mod N), where r = 2^(# of key bits) |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 410 | r = 2L**key.modulus.bit_length() |
| 411 | rrmodn = r * r % key.modulus |
| 412 | ret.extend(struct.pack('!II', key.num_bits, n0inv)) |
| 413 | ret.extend(encode_long(key.num_bits, key.modulus)) |
| 414 | ret.extend(encode_long(key.num_bits, rrmodn)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 415 | return ret |
| 416 | |
| 417 | |
| 418 | def lookup_algorithm_by_type(alg_type): |
| 419 | """Looks up algorithm by type. |
| 420 | |
| 421 | Arguments: |
| 422 | alg_type: The integer representing the type. |
| 423 | |
| 424 | Returns: |
| 425 | A tuple with the algorithm name and an |Algorithm| instance. |
| 426 | |
| 427 | Raises: |
| 428 | Exception: If the algorithm cannot be found |
| 429 | """ |
| 430 | for alg_name in ALGORITHMS: |
| 431 | alg_data = ALGORITHMS[alg_name] |
| 432 | if alg_data.algorithm_type == alg_type: |
| 433 | return (alg_name, alg_data) |
| 434 | raise AvbError('Unknown algorithm type {}'.format(alg_type)) |
| 435 | |
| 436 | |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 437 | def raw_sign(signing_helper, algorithm_name, signature_num_bytes, key_path, |
| 438 | raw_data_to_sign): |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 439 | """Computes a raw RSA signature using |signing_helper| or openssl. |
| 440 | |
| 441 | Arguments: |
| 442 | signing_helper: Program which signs a hash and returns the signature. |
| 443 | algorithm_name: The algorithm name as per the ALGORITHMS dict. |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 444 | signature_num_bytes: Number of bytes used to store the signature. |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 445 | key_path: Path to the private key file. Must be PEM format. |
| 446 | raw_data_to_sign: Data to sign (bytearray or str expected). |
| 447 | |
| 448 | Returns: |
| 449 | A bytearray containing the signature. |
| 450 | |
| 451 | Raises: |
| 452 | Exception: If an error occurs. |
| 453 | """ |
| 454 | p = None |
| 455 | if signing_helper is not None: |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 456 | p = subprocess.Popen( |
| 457 | [signing_helper, algorithm_name, key_path], |
| 458 | stdin=subprocess.PIPE, |
| 459 | stdout=subprocess.PIPE, |
| 460 | stderr=subprocess.PIPE) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 461 | else: |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 462 | p = subprocess.Popen( |
| 463 | ['openssl', 'rsautl', '-sign', '-inkey', key_path, '-raw'], |
| 464 | stdin=subprocess.PIPE, |
| 465 | stdout=subprocess.PIPE, |
| 466 | stderr=subprocess.PIPE) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 467 | (pout, perr) = p.communicate(str(raw_data_to_sign)) |
| 468 | retcode = p.wait() |
| 469 | if retcode != 0: |
| 470 | raise AvbError('Error signing: {}'.format(perr)) |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 471 | signature = bytearray(pout) |
| 472 | if len(signature) != signature_num_bytes: |
| 473 | raise AvbError('Error signing: Invalid length of signature') |
| 474 | return signature |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 475 | |
| 476 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 477 | def verify_vbmeta_signature(vbmeta_header, vbmeta_blob): |
| 478 | """Checks that the signature in a vbmeta blob was made by |
| 479 | the embedded public key. |
| 480 | |
| 481 | Arguments: |
| 482 | vbmeta_header: A AvbVBMetaHeader. |
| 483 | vbmeta_blob: The whole vbmeta blob, including the header. |
| 484 | |
| 485 | Returns: |
| 486 | True if the signature is valid and corresponds to the embedded |
| 487 | public key. Also returns True if the vbmeta blob is not signed. |
| 488 | """ |
| 489 | (_, alg) = lookup_algorithm_by_type(vbmeta_header.algorithm_type) |
| 490 | if alg.hash_name == '': |
| 491 | return True |
| 492 | header_blob = vbmeta_blob[0:256] |
| 493 | auth_offset = 256 |
| 494 | aux_offset = auth_offset + vbmeta_header.authentication_data_block_size |
| 495 | aux_size = vbmeta_header.auxiliary_data_block_size |
| 496 | aux_blob = vbmeta_blob[aux_offset:aux_offset + aux_size] |
| 497 | pubkey_offset = aux_offset + vbmeta_header.public_key_offset |
| 498 | pubkey_size = vbmeta_header.public_key_size |
| 499 | pubkey_blob = vbmeta_blob[pubkey_offset:pubkey_offset + pubkey_size] |
| 500 | |
| 501 | digest_offset = auth_offset + vbmeta_header.hash_offset |
| 502 | digest_size = vbmeta_header.hash_size |
| 503 | digest_blob = vbmeta_blob[digest_offset:digest_offset + digest_size] |
| 504 | |
| 505 | sig_offset = auth_offset + vbmeta_header.signature_offset |
| 506 | sig_size = vbmeta_header.signature_size |
| 507 | sig_blob = vbmeta_blob[sig_offset:sig_offset + sig_size] |
| 508 | |
| 509 | # Now that we've got the stored digest, public key, and signature |
| 510 | # all we need to do is to verify. This is the exactly the same |
| 511 | # steps as performed in the avb_vbmeta_image_verify() function in |
| 512 | # libavb/avb_vbmeta_image.c. |
| 513 | |
| 514 | ha = hashlib.new(alg.hash_name) |
| 515 | ha.update(header_blob) |
| 516 | ha.update(aux_blob) |
| 517 | computed_digest = ha.digest() |
| 518 | |
| 519 | if computed_digest != digest_blob: |
| 520 | return False |
| 521 | |
| 522 | padding_and_digest = bytearray(alg.padding) |
| 523 | padding_and_digest.extend(computed_digest) |
| 524 | |
| 525 | (num_bits,) = struct.unpack('!I', pubkey_blob[0:4]) |
| 526 | modulus_blob = pubkey_blob[8:8 + num_bits/8] |
| 527 | modulus = decode_long(modulus_blob) |
| 528 | exponent = 65537 |
| 529 | |
| 530 | # For now, just use Crypto.PublicKey.RSA to verify the signature. This |
| 531 | # is OK since 'avbtool verify_image' is not expected to run on the |
| 532 | # Android builders (see bug #36809096). |
| 533 | import Crypto.PublicKey.RSA |
| 534 | key = Crypto.PublicKey.RSA.construct((modulus, long(exponent))) |
| 535 | if not key.verify(decode_long(padding_and_digest), |
| 536 | (decode_long(sig_blob), None)): |
| 537 | return False |
| 538 | return True |
| 539 | |
| 540 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 541 | class ImageChunk(object): |
| 542 | """Data structure used for representing chunks in Android sparse files. |
| 543 | |
| 544 | Attributes: |
| 545 | chunk_type: One of TYPE_RAW, TYPE_FILL, or TYPE_DONT_CARE. |
| 546 | chunk_offset: Offset in the sparse file where this chunk begins. |
| 547 | output_offset: Offset in de-sparsified file where output begins. |
| 548 | output_size: Number of bytes in output. |
| 549 | input_offset: Offset in sparse file for data if TYPE_RAW otherwise None. |
| 550 | fill_data: Blob with data to fill if TYPE_FILL otherwise None. |
| 551 | """ |
| 552 | |
| 553 | FORMAT = '<2H2I' |
| 554 | TYPE_RAW = 0xcac1 |
| 555 | TYPE_FILL = 0xcac2 |
| 556 | TYPE_DONT_CARE = 0xcac3 |
| 557 | TYPE_CRC32 = 0xcac4 |
| 558 | |
| 559 | def __init__(self, chunk_type, chunk_offset, output_offset, output_size, |
| 560 | input_offset, fill_data): |
| 561 | """Initializes an ImageChunk object. |
| 562 | |
| 563 | Arguments: |
| 564 | chunk_type: One of TYPE_RAW, TYPE_FILL, or TYPE_DONT_CARE. |
| 565 | chunk_offset: Offset in the sparse file where this chunk begins. |
| 566 | output_offset: Offset in de-sparsified file. |
| 567 | output_size: Number of bytes in output. |
| 568 | input_offset: Offset in sparse file if TYPE_RAW otherwise None. |
| 569 | fill_data: Blob with data to fill if TYPE_FILL otherwise None. |
| 570 | |
| 571 | Raises: |
| 572 | ValueError: If data is not well-formed. |
| 573 | """ |
| 574 | self.chunk_type = chunk_type |
| 575 | self.chunk_offset = chunk_offset |
| 576 | self.output_offset = output_offset |
| 577 | self.output_size = output_size |
| 578 | self.input_offset = input_offset |
| 579 | self.fill_data = fill_data |
| 580 | # Check invariants. |
| 581 | if self.chunk_type == self.TYPE_RAW: |
| 582 | if self.fill_data is not None: |
| 583 | raise ValueError('RAW chunk cannot have fill_data set.') |
| 584 | if not self.input_offset: |
| 585 | raise ValueError('RAW chunk must have input_offset set.') |
| 586 | elif self.chunk_type == self.TYPE_FILL: |
| 587 | if self.fill_data is None: |
| 588 | raise ValueError('FILL chunk must have fill_data set.') |
| 589 | if self.input_offset: |
| 590 | raise ValueError('FILL chunk cannot have input_offset set.') |
| 591 | elif self.chunk_type == self.TYPE_DONT_CARE: |
| 592 | if self.fill_data is not None: |
| 593 | raise ValueError('DONT_CARE chunk cannot have fill_data set.') |
| 594 | if self.input_offset: |
| 595 | raise ValueError('DONT_CARE chunk cannot have input_offset set.') |
| 596 | else: |
| 597 | raise ValueError('Invalid chunk type') |
| 598 | |
| 599 | |
| 600 | class ImageHandler(object): |
| 601 | """Abstraction for image I/O with support for Android sparse images. |
| 602 | |
| 603 | This class provides an interface for working with image files that |
| 604 | may be using the Android Sparse Image format. When an instance is |
| 605 | constructed, we test whether it's an Android sparse file. If so, |
| 606 | operations will be on the sparse file by interpreting the sparse |
| 607 | format, otherwise they will be directly on the file. Either way the |
| 608 | operations do the same. |
| 609 | |
| 610 | For reading, this interface mimics a file object - it has seek(), |
| 611 | tell(), and read() methods. For writing, only truncation |
| 612 | (truncate()) and appending is supported (append_raw() and |
| 613 | append_dont_care()). Additionally, data can only be written in units |
| 614 | of the block size. |
| 615 | |
| 616 | Attributes: |
| 617 | is_sparse: Whether the file being operated on is sparse. |
| 618 | block_size: The block size, typically 4096. |
| 619 | image_size: The size of the unsparsified file. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 620 | """ |
| 621 | # See system/core/libsparse/sparse_format.h for details. |
| 622 | MAGIC = 0xed26ff3a |
| 623 | HEADER_FORMAT = '<I4H4I' |
| 624 | |
| 625 | # These are formats and offset of just the |total_chunks| and |
| 626 | # |total_blocks| fields. |
| 627 | NUM_CHUNKS_AND_BLOCKS_FORMAT = '<II' |
| 628 | NUM_CHUNKS_AND_BLOCKS_OFFSET = 16 |
| 629 | |
| 630 | def __init__(self, image_filename): |
| 631 | """Initializes an image handler. |
| 632 | |
| 633 | Arguments: |
| 634 | image_filename: The name of the file to operate on. |
| 635 | |
| 636 | Raises: |
| 637 | ValueError: If data in the file is invalid. |
| 638 | """ |
| 639 | self._image_filename = image_filename |
| 640 | self._read_header() |
| 641 | |
| 642 | def _read_header(self): |
| 643 | """Initializes internal data structures used for reading file. |
| 644 | |
| 645 | This may be called multiple times and is typically called after |
| 646 | modifying the file (e.g. appending, truncation). |
| 647 | |
| 648 | Raises: |
| 649 | ValueError: If data in the file is invalid. |
| 650 | """ |
| 651 | self.is_sparse = False |
| 652 | self.block_size = 4096 |
| 653 | self._file_pos = 0 |
| 654 | self._image = open(self._image_filename, 'r+b') |
| 655 | self._image.seek(0, os.SEEK_END) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 656 | self.image_size = self._image.tell() |
| 657 | |
| 658 | self._image.seek(0, os.SEEK_SET) |
| 659 | header_bin = self._image.read(struct.calcsize(self.HEADER_FORMAT)) |
| 660 | (magic, major_version, minor_version, file_hdr_sz, chunk_hdr_sz, |
| 661 | block_size, self._num_total_blocks, self._num_total_chunks, |
| 662 | _) = struct.unpack(self.HEADER_FORMAT, header_bin) |
| 663 | if magic != self.MAGIC: |
| 664 | # Not a sparse image, our job here is done. |
| 665 | return |
| 666 | if not (major_version == 1 and minor_version == 0): |
| 667 | raise ValueError('Encountered sparse image format version {}.{} but ' |
| 668 | 'only 1.0 is supported'.format(major_version, |
| 669 | minor_version)) |
| 670 | if file_hdr_sz != struct.calcsize(self.HEADER_FORMAT): |
| 671 | raise ValueError('Unexpected file_hdr_sz value {}.'. |
| 672 | format(file_hdr_sz)) |
| 673 | if chunk_hdr_sz != struct.calcsize(ImageChunk.FORMAT): |
| 674 | raise ValueError('Unexpected chunk_hdr_sz value {}.'. |
| 675 | format(chunk_hdr_sz)) |
| 676 | |
| 677 | self.block_size = block_size |
| 678 | |
| 679 | # Build an list of chunks by parsing the file. |
| 680 | self._chunks = [] |
| 681 | |
| 682 | # Find the smallest offset where only "Don't care" chunks |
| 683 | # follow. This will be the size of the content in the sparse |
| 684 | # image. |
| 685 | offset = 0 |
| 686 | output_offset = 0 |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 687 | for _ in xrange(1, self._num_total_chunks + 1): |
| 688 | chunk_offset = self._image.tell() |
| 689 | |
| 690 | header_bin = self._image.read(struct.calcsize(ImageChunk.FORMAT)) |
| 691 | (chunk_type, _, chunk_sz, total_sz) = struct.unpack(ImageChunk.FORMAT, |
| 692 | header_bin) |
| 693 | data_sz = total_sz - struct.calcsize(ImageChunk.FORMAT) |
| 694 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 695 | if chunk_type == ImageChunk.TYPE_RAW: |
| 696 | if data_sz != (chunk_sz * self.block_size): |
| 697 | raise ValueError('Raw chunk input size ({}) does not match output ' |
| 698 | 'size ({})'. |
| 699 | format(data_sz, chunk_sz*self.block_size)) |
| 700 | self._chunks.append(ImageChunk(ImageChunk.TYPE_RAW, |
| 701 | chunk_offset, |
| 702 | output_offset, |
| 703 | chunk_sz*self.block_size, |
| 704 | self._image.tell(), |
| 705 | None)) |
| 706 | self._image.read(data_sz) |
| 707 | |
| 708 | elif chunk_type == ImageChunk.TYPE_FILL: |
| 709 | if data_sz != 4: |
| 710 | raise ValueError('Fill chunk should have 4 bytes of fill, but this ' |
| 711 | 'has {}'.format(data_sz)) |
| 712 | fill_data = self._image.read(4) |
| 713 | self._chunks.append(ImageChunk(ImageChunk.TYPE_FILL, |
| 714 | chunk_offset, |
| 715 | output_offset, |
| 716 | chunk_sz*self.block_size, |
| 717 | None, |
| 718 | fill_data)) |
| 719 | elif chunk_type == ImageChunk.TYPE_DONT_CARE: |
| 720 | if data_sz != 0: |
| 721 | raise ValueError('Don\'t care chunk input size is non-zero ({})'. |
| 722 | format(data_sz)) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 723 | self._chunks.append(ImageChunk(ImageChunk.TYPE_DONT_CARE, |
| 724 | chunk_offset, |
| 725 | output_offset, |
| 726 | chunk_sz*self.block_size, |
| 727 | None, |
| 728 | None)) |
| 729 | elif chunk_type == ImageChunk.TYPE_CRC32: |
| 730 | if data_sz != 4: |
| 731 | raise ValueError('CRC32 chunk should have 4 bytes of CRC, but ' |
| 732 | 'this has {}'.format(data_sz)) |
| 733 | self._image.read(4) |
| 734 | else: |
| 735 | raise ValueError('Unknown chunk type {}'.format(chunk_type)) |
| 736 | |
| 737 | offset += chunk_sz |
| 738 | output_offset += chunk_sz*self.block_size |
| 739 | |
| 740 | # Record where sparse data end. |
| 741 | self._sparse_end = self._image.tell() |
| 742 | |
| 743 | # Now that we've traversed all chunks, sanity check. |
| 744 | if self._num_total_blocks != offset: |
| 745 | raise ValueError('The header said we should have {} output blocks, ' |
| 746 | 'but we saw {}'.format(self._num_total_blocks, offset)) |
| 747 | junk_len = len(self._image.read()) |
| 748 | if junk_len > 0: |
| 749 | raise ValueError('There were {} bytes of extra data at the end of the ' |
| 750 | 'file.'.format(junk_len)) |
| 751 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 752 | # Assign |image_size|. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 753 | self.image_size = output_offset |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 754 | |
| 755 | # This is used when bisecting in read() to find the initial slice. |
| 756 | self._chunk_output_offsets = [i.output_offset for i in self._chunks] |
| 757 | |
| 758 | self.is_sparse = True |
| 759 | |
| 760 | def _update_chunks_and_blocks(self): |
| 761 | """Helper function to update the image header. |
| 762 | |
| 763 | The the |total_chunks| and |total_blocks| fields in the header |
| 764 | will be set to value of the |_num_total_blocks| and |
| 765 | |_num_total_chunks| attributes. |
| 766 | |
| 767 | """ |
| 768 | self._image.seek(self.NUM_CHUNKS_AND_BLOCKS_OFFSET, os.SEEK_SET) |
| 769 | self._image.write(struct.pack(self.NUM_CHUNKS_AND_BLOCKS_FORMAT, |
| 770 | self._num_total_blocks, |
| 771 | self._num_total_chunks)) |
| 772 | |
| 773 | def append_dont_care(self, num_bytes): |
| 774 | """Appends a DONT_CARE chunk to the sparse file. |
| 775 | |
| 776 | The given number of bytes must be a multiple of the block size. |
| 777 | |
| 778 | Arguments: |
| 779 | num_bytes: Size in number of bytes of the DONT_CARE chunk. |
| 780 | """ |
| 781 | assert num_bytes % self.block_size == 0 |
| 782 | |
| 783 | if not self.is_sparse: |
| 784 | self._image.seek(0, os.SEEK_END) |
| 785 | # This is more efficient that writing NUL bytes since it'll add |
| 786 | # a hole on file systems that support sparse files (native |
| 787 | # sparse, not Android sparse). |
| 788 | self._image.truncate(self._image.tell() + num_bytes) |
| 789 | self._read_header() |
| 790 | return |
| 791 | |
| 792 | self._num_total_chunks += 1 |
| 793 | self._num_total_blocks += num_bytes / self.block_size |
| 794 | self._update_chunks_and_blocks() |
| 795 | |
| 796 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 797 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 798 | ImageChunk.TYPE_DONT_CARE, |
| 799 | 0, # Reserved |
| 800 | num_bytes / self.block_size, |
| 801 | struct.calcsize(ImageChunk.FORMAT))) |
| 802 | self._read_header() |
| 803 | |
| 804 | def append_raw(self, data): |
| 805 | """Appends a RAW chunk to the sparse file. |
| 806 | |
| 807 | The length of the given data must be a multiple of the block size. |
| 808 | |
| 809 | Arguments: |
| 810 | data: Data to append. |
| 811 | """ |
| 812 | assert len(data) % self.block_size == 0 |
| 813 | |
| 814 | if not self.is_sparse: |
| 815 | self._image.seek(0, os.SEEK_END) |
| 816 | self._image.write(data) |
| 817 | self._read_header() |
| 818 | return |
| 819 | |
| 820 | self._num_total_chunks += 1 |
| 821 | self._num_total_blocks += len(data) / self.block_size |
| 822 | self._update_chunks_and_blocks() |
| 823 | |
| 824 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 825 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 826 | ImageChunk.TYPE_RAW, |
| 827 | 0, # Reserved |
| 828 | len(data) / self.block_size, |
| 829 | len(data) + |
| 830 | struct.calcsize(ImageChunk.FORMAT))) |
| 831 | self._image.write(data) |
| 832 | self._read_header() |
| 833 | |
| 834 | def append_fill(self, fill_data, size): |
| 835 | """Appends a fill chunk to the sparse file. |
| 836 | |
| 837 | The total length of the fill data must be a multiple of the block size. |
| 838 | |
| 839 | Arguments: |
| 840 | fill_data: Fill data to append - must be four bytes. |
| 841 | size: Number of chunk - must be a multiple of four and the block size. |
| 842 | """ |
| 843 | assert len(fill_data) == 4 |
| 844 | assert size % 4 == 0 |
| 845 | assert size % self.block_size == 0 |
| 846 | |
| 847 | if not self.is_sparse: |
| 848 | self._image.seek(0, os.SEEK_END) |
| 849 | self._image.write(fill_data * (size/4)) |
| 850 | self._read_header() |
| 851 | return |
| 852 | |
| 853 | self._num_total_chunks += 1 |
| 854 | self._num_total_blocks += size / self.block_size |
| 855 | self._update_chunks_and_blocks() |
| 856 | |
| 857 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 858 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 859 | ImageChunk.TYPE_FILL, |
| 860 | 0, # Reserved |
| 861 | size / self.block_size, |
| 862 | 4 + struct.calcsize(ImageChunk.FORMAT))) |
| 863 | self._image.write(fill_data) |
| 864 | self._read_header() |
| 865 | |
| 866 | def seek(self, offset): |
| 867 | """Sets the cursor position for reading from unsparsified file. |
| 868 | |
| 869 | Arguments: |
| 870 | offset: Offset to seek to from the beginning of the file. |
| 871 | """ |
| 872 | self._file_pos = offset |
| 873 | |
| 874 | def read(self, size): |
| 875 | """Reads data from the unsparsified file. |
| 876 | |
| 877 | This method may return fewer than |size| bytes of data if the end |
| 878 | of the file was encountered. |
| 879 | |
| 880 | The file cursor for reading is advanced by the number of bytes |
| 881 | read. |
| 882 | |
| 883 | Arguments: |
| 884 | size: Number of bytes to read. |
| 885 | |
| 886 | Returns: |
| 887 | The data. |
| 888 | |
| 889 | """ |
| 890 | if not self.is_sparse: |
| 891 | self._image.seek(self._file_pos) |
| 892 | data = self._image.read(size) |
| 893 | self._file_pos += len(data) |
| 894 | return data |
| 895 | |
| 896 | # Iterate over all chunks. |
| 897 | chunk_idx = bisect.bisect_right(self._chunk_output_offsets, |
| 898 | self._file_pos) - 1 |
| 899 | data = bytearray() |
| 900 | to_go = size |
| 901 | while to_go > 0: |
| 902 | chunk = self._chunks[chunk_idx] |
| 903 | chunk_pos_offset = self._file_pos - chunk.output_offset |
| 904 | chunk_pos_to_go = min(chunk.output_size - chunk_pos_offset, to_go) |
| 905 | |
| 906 | if chunk.chunk_type == ImageChunk.TYPE_RAW: |
| 907 | self._image.seek(chunk.input_offset + chunk_pos_offset) |
| 908 | data.extend(self._image.read(chunk_pos_to_go)) |
| 909 | elif chunk.chunk_type == ImageChunk.TYPE_FILL: |
| 910 | all_data = chunk.fill_data*(chunk_pos_to_go/len(chunk.fill_data) + 2) |
| 911 | offset_mod = chunk_pos_offset % len(chunk.fill_data) |
| 912 | data.extend(all_data[offset_mod:(offset_mod + chunk_pos_to_go)]) |
| 913 | else: |
| 914 | assert chunk.chunk_type == ImageChunk.TYPE_DONT_CARE |
| 915 | data.extend('\0' * chunk_pos_to_go) |
| 916 | |
| 917 | to_go -= chunk_pos_to_go |
| 918 | self._file_pos += chunk_pos_to_go |
| 919 | chunk_idx += 1 |
| 920 | # Generate partial read in case of EOF. |
| 921 | if chunk_idx >= len(self._chunks): |
| 922 | break |
| 923 | |
| 924 | return data |
| 925 | |
| 926 | def tell(self): |
| 927 | """Returns the file cursor position for reading from unsparsified file. |
| 928 | |
| 929 | Returns: |
| 930 | The file cursor position for reading. |
| 931 | """ |
| 932 | return self._file_pos |
| 933 | |
| 934 | def truncate(self, size): |
| 935 | """Truncates the unsparsified file. |
| 936 | |
| 937 | Arguments: |
| 938 | size: Desired size of unsparsified file. |
| 939 | |
| 940 | Raises: |
| 941 | ValueError: If desired size isn't a multiple of the block size. |
| 942 | """ |
| 943 | if not self.is_sparse: |
| 944 | self._image.truncate(size) |
| 945 | self._read_header() |
| 946 | return |
| 947 | |
| 948 | if size % self.block_size != 0: |
| 949 | raise ValueError('Cannot truncate to a size which is not a multiple ' |
| 950 | 'of the block size') |
| 951 | |
| 952 | if size == self.image_size: |
| 953 | # Trivial where there's nothing to do. |
| 954 | return |
| 955 | elif size < self.image_size: |
| 956 | chunk_idx = bisect.bisect_right(self._chunk_output_offsets, size) - 1 |
| 957 | chunk = self._chunks[chunk_idx] |
| 958 | if chunk.output_offset != size: |
| 959 | # Truncation in the middle of a trunk - need to keep the chunk |
| 960 | # and modify it. |
| 961 | chunk_idx_for_update = chunk_idx + 1 |
| 962 | num_to_keep = size - chunk.output_offset |
| 963 | assert num_to_keep % self.block_size == 0 |
| 964 | if chunk.chunk_type == ImageChunk.TYPE_RAW: |
| 965 | truncate_at = (chunk.chunk_offset + |
| 966 | struct.calcsize(ImageChunk.FORMAT) + num_to_keep) |
| 967 | data_sz = num_to_keep |
| 968 | elif chunk.chunk_type == ImageChunk.TYPE_FILL: |
| 969 | truncate_at = (chunk.chunk_offset + |
| 970 | struct.calcsize(ImageChunk.FORMAT) + 4) |
| 971 | data_sz = 4 |
| 972 | else: |
| 973 | assert chunk.chunk_type == ImageChunk.TYPE_DONT_CARE |
| 974 | truncate_at = chunk.chunk_offset + struct.calcsize(ImageChunk.FORMAT) |
| 975 | data_sz = 0 |
| 976 | chunk_sz = num_to_keep/self.block_size |
| 977 | total_sz = data_sz + struct.calcsize(ImageChunk.FORMAT) |
| 978 | self._image.seek(chunk.chunk_offset) |
| 979 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 980 | chunk.chunk_type, |
| 981 | 0, # Reserved |
| 982 | chunk_sz, |
| 983 | total_sz)) |
| 984 | chunk.output_size = num_to_keep |
| 985 | else: |
| 986 | # Truncation at trunk boundary. |
| 987 | truncate_at = chunk.chunk_offset |
| 988 | chunk_idx_for_update = chunk_idx |
| 989 | |
| 990 | self._num_total_chunks = chunk_idx_for_update |
| 991 | self._num_total_blocks = 0 |
| 992 | for i in range(0, chunk_idx_for_update): |
| 993 | self._num_total_blocks += self._chunks[i].output_size / self.block_size |
| 994 | self._update_chunks_and_blocks() |
| 995 | self._image.truncate(truncate_at) |
| 996 | |
| 997 | # We've modified the file so re-read all data. |
| 998 | self._read_header() |
| 999 | else: |
| 1000 | # Truncating to grow - just add a DONT_CARE section. |
| 1001 | self.append_dont_care(size - self.image_size) |
| 1002 | |
| 1003 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1004 | class AvbDescriptor(object): |
| 1005 | """Class for AVB descriptor. |
| 1006 | |
| 1007 | See the |AvbDescriptor| C struct for more information. |
| 1008 | |
| 1009 | Attributes: |
| 1010 | tag: The tag identifying what kind of descriptor this is. |
| 1011 | data: The data in the descriptor. |
| 1012 | """ |
| 1013 | |
| 1014 | SIZE = 16 |
| 1015 | FORMAT_STRING = ('!QQ') # tag, num_bytes_following (descriptor header) |
| 1016 | |
| 1017 | def __init__(self, data): |
| 1018 | """Initializes a new property descriptor. |
| 1019 | |
| 1020 | Arguments: |
| 1021 | data: If not None, must be a bytearray(). |
| 1022 | |
| 1023 | Raises: |
| 1024 | LookupError: If the given descriptor is malformed. |
| 1025 | """ |
| 1026 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1027 | |
| 1028 | if data: |
| 1029 | (self.tag, num_bytes_following) = ( |
| 1030 | struct.unpack(self.FORMAT_STRING, data[0:self.SIZE])) |
| 1031 | self.data = data[self.SIZE:self.SIZE + num_bytes_following] |
| 1032 | else: |
| 1033 | self.tag = None |
| 1034 | self.data = None |
| 1035 | |
| 1036 | def print_desc(self, o): |
| 1037 | """Print the descriptor. |
| 1038 | |
| 1039 | Arguments: |
| 1040 | o: The object to write the output to. |
| 1041 | """ |
| 1042 | o.write(' Unknown descriptor:\n') |
| 1043 | o.write(' Tag: {}\n'.format(self.tag)) |
| 1044 | if len(self.data) < 256: |
| 1045 | o.write(' Data: {} ({} bytes)\n'.format( |
| 1046 | repr(str(self.data)), len(self.data))) |
| 1047 | else: |
| 1048 | o.write(' Data: {} bytes\n'.format(len(self.data))) |
| 1049 | |
| 1050 | def encode(self): |
| 1051 | """Serializes the descriptor. |
| 1052 | |
| 1053 | Returns: |
| 1054 | A bytearray() with the descriptor data. |
| 1055 | """ |
| 1056 | num_bytes_following = len(self.data) |
| 1057 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1058 | padding_size = nbf_with_padding - num_bytes_following |
| 1059 | desc = struct.pack(self.FORMAT_STRING, self.tag, nbf_with_padding) |
| 1060 | padding = struct.pack(str(padding_size) + 'x') |
| 1061 | ret = desc + self.data + padding |
| 1062 | return bytearray(ret) |
| 1063 | |
| 1064 | |
| 1065 | class AvbPropertyDescriptor(AvbDescriptor): |
| 1066 | """A class for property descriptors. |
| 1067 | |
| 1068 | See the |AvbPropertyDescriptor| C struct for more information. |
| 1069 | |
| 1070 | Attributes: |
| 1071 | key: The key. |
| 1072 | value: The key. |
| 1073 | """ |
| 1074 | |
| 1075 | TAG = 0 |
| 1076 | SIZE = 32 |
| 1077 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 1078 | 'Q' # key size (bytes) |
| 1079 | 'Q') # value size (bytes) |
| 1080 | |
| 1081 | def __init__(self, data=None): |
| 1082 | """Initializes a new property descriptor. |
| 1083 | |
| 1084 | Arguments: |
| 1085 | data: If not None, must be a bytearray of size |SIZE|. |
| 1086 | |
| 1087 | Raises: |
| 1088 | LookupError: If the given descriptor is malformed. |
| 1089 | """ |
| 1090 | AvbDescriptor.__init__(self, None) |
| 1091 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1092 | |
| 1093 | if data: |
| 1094 | (tag, num_bytes_following, key_size, |
| 1095 | value_size) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
| 1096 | expected_size = round_to_multiple( |
| 1097 | self.SIZE - 16 + key_size + 1 + value_size + 1, 8) |
| 1098 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1099 | raise LookupError('Given data does not look like a property ' |
| 1100 | 'descriptor.') |
| 1101 | self.key = data[self.SIZE:(self.SIZE + key_size)] |
| 1102 | self.value = data[(self.SIZE + key_size + 1):(self.SIZE + key_size + 1 + |
| 1103 | value_size)] |
| 1104 | else: |
| 1105 | self.key = '' |
| 1106 | self.value = '' |
| 1107 | |
| 1108 | def print_desc(self, o): |
| 1109 | """Print the descriptor. |
| 1110 | |
| 1111 | Arguments: |
| 1112 | o: The object to write the output to. |
| 1113 | """ |
| 1114 | if len(self.value) < 256: |
| 1115 | o.write(' Prop: {} -> {}\n'.format(self.key, repr(str(self.value)))) |
| 1116 | else: |
| 1117 | o.write(' Prop: {} -> ({} bytes)\n'.format(self.key, len(self.value))) |
| 1118 | |
| 1119 | def encode(self): |
| 1120 | """Serializes the descriptor. |
| 1121 | |
| 1122 | Returns: |
| 1123 | A bytearray() with the descriptor data. |
| 1124 | """ |
| 1125 | num_bytes_following = self.SIZE + len(self.key) + len(self.value) + 2 - 16 |
| 1126 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1127 | padding_size = nbf_with_padding - num_bytes_following |
| 1128 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 1129 | len(self.key), len(self.value)) |
| 1130 | padding = struct.pack(str(padding_size) + 'x') |
| 1131 | ret = desc + self.key + '\0' + self.value + '\0' + padding |
| 1132 | return bytearray(ret) |
| 1133 | |
| 1134 | |
| 1135 | class AvbHashtreeDescriptor(AvbDescriptor): |
| 1136 | """A class for hashtree descriptors. |
| 1137 | |
| 1138 | See the |AvbHashtreeDescriptor| C struct for more information. |
| 1139 | |
| 1140 | Attributes: |
| 1141 | dm_verity_version: dm-verity version used. |
| 1142 | image_size: Size of the image, after rounding up to |block_size|. |
| 1143 | tree_offset: Offset of the hash tree in the file. |
| 1144 | tree_size: Size of the tree. |
| 1145 | data_block_size: Data block size |
| 1146 | hash_block_size: Hash block size |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1147 | fec_num_roots: Number of roots used for FEC (0 if FEC is not used). |
| 1148 | fec_offset: Offset of FEC data (0 if FEC is not used). |
| 1149 | fec_size: Size of FEC data (0 if FEC is not used). |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1150 | hash_algorithm: Hash algorithm used. |
| 1151 | partition_name: Partition name. |
| 1152 | salt: Salt used. |
| 1153 | root_digest: Root digest. |
| 1154 | """ |
| 1155 | |
| 1156 | TAG = 1 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1157 | RESERVED = 64 |
| 1158 | SIZE = 116 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1159 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 1160 | 'L' # dm-verity version used |
| 1161 | 'Q' # image size (bytes) |
| 1162 | 'Q' # tree offset (bytes) |
| 1163 | 'Q' # tree size (bytes) |
| 1164 | 'L' # data block size (bytes) |
| 1165 | 'L' # hash block size (bytes) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1166 | 'L' # FEC number of roots |
| 1167 | 'Q' # FEC offset (bytes) |
| 1168 | 'Q' # FEC size (bytes) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1169 | '32s' # hash algorithm used |
| 1170 | 'L' # partition name (bytes) |
| 1171 | 'L' # salt length (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1172 | 'L' + # root digest length (bytes) |
| 1173 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1174 | |
| 1175 | def __init__(self, data=None): |
| 1176 | """Initializes a new hashtree descriptor. |
| 1177 | |
| 1178 | Arguments: |
| 1179 | data: If not None, must be a bytearray of size |SIZE|. |
| 1180 | |
| 1181 | Raises: |
| 1182 | LookupError: If the given descriptor is malformed. |
| 1183 | """ |
| 1184 | AvbDescriptor.__init__(self, None) |
| 1185 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1186 | |
| 1187 | if data: |
| 1188 | (tag, num_bytes_following, self.dm_verity_version, self.image_size, |
| 1189 | self.tree_offset, self.tree_size, self.data_block_size, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1190 | self.hash_block_size, self.fec_num_roots, self.fec_offset, self.fec_size, |
| 1191 | self.hash_algorithm, partition_name_len, salt_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1192 | root_digest_len, _) = struct.unpack(self.FORMAT_STRING, |
| 1193 | data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1194 | expected_size = round_to_multiple( |
| 1195 | self.SIZE - 16 + partition_name_len + salt_len + root_digest_len, 8) |
| 1196 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1197 | raise LookupError('Given data does not look like a hashtree ' |
| 1198 | 'descriptor.') |
| 1199 | # Nuke NUL-bytes at the end. |
| 1200 | self.hash_algorithm = self.hash_algorithm.split('\0', 1)[0] |
| 1201 | o = 0 |
| 1202 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1203 | partition_name_len)]) |
| 1204 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1205 | self.partition_name.decode('utf-8') |
| 1206 | o += partition_name_len |
| 1207 | self.salt = data[(self.SIZE + o):(self.SIZE + o + salt_len)] |
| 1208 | o += salt_len |
| 1209 | self.root_digest = data[(self.SIZE + o):(self.SIZE + o + root_digest_len)] |
| 1210 | if root_digest_len != len(hashlib.new(name=self.hash_algorithm).digest()): |
| 1211 | raise LookupError('root_digest_len doesn\'t match hash algorithm') |
| 1212 | |
| 1213 | else: |
| 1214 | self.dm_verity_version = 0 |
| 1215 | self.image_size = 0 |
| 1216 | self.tree_offset = 0 |
| 1217 | self.tree_size = 0 |
| 1218 | self.data_block_size = 0 |
| 1219 | self.hash_block_size = 0 |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1220 | self.fec_num_roots = 0 |
| 1221 | self.fec_offset = 0 |
| 1222 | self.fec_size = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1223 | self.hash_algorithm = '' |
| 1224 | self.partition_name = '' |
| 1225 | self.salt = bytearray() |
| 1226 | self.root_digest = bytearray() |
| 1227 | |
| 1228 | def print_desc(self, o): |
| 1229 | """Print the descriptor. |
| 1230 | |
| 1231 | Arguments: |
| 1232 | o: The object to write the output to. |
| 1233 | """ |
| 1234 | o.write(' Hashtree descriptor:\n') |
| 1235 | o.write(' Version of dm-verity: {}\n'.format(self.dm_verity_version)) |
| 1236 | o.write(' Image Size: {} bytes\n'.format(self.image_size)) |
| 1237 | o.write(' Tree Offset: {}\n'.format(self.tree_offset)) |
| 1238 | o.write(' Tree Size: {} bytes\n'.format(self.tree_size)) |
| 1239 | o.write(' Data Block Size: {} bytes\n'.format( |
| 1240 | self.data_block_size)) |
| 1241 | o.write(' Hash Block Size: {} bytes\n'.format( |
| 1242 | self.hash_block_size)) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1243 | o.write(' FEC num roots: {}\n'.format(self.fec_num_roots)) |
| 1244 | o.write(' FEC offset: {}\n'.format(self.fec_offset)) |
| 1245 | o.write(' FEC size: {} bytes\n'.format(self.fec_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1246 | o.write(' Hash Algorithm: {}\n'.format(self.hash_algorithm)) |
| 1247 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1248 | o.write(' Salt: {}\n'.format(str(self.salt).encode( |
| 1249 | 'hex'))) |
| 1250 | o.write(' Root Digest: {}\n'.format(str( |
| 1251 | self.root_digest).encode('hex'))) |
| 1252 | |
| 1253 | def encode(self): |
| 1254 | """Serializes the descriptor. |
| 1255 | |
| 1256 | Returns: |
| 1257 | A bytearray() with the descriptor data. |
| 1258 | """ |
| 1259 | encoded_name = self.partition_name.encode('utf-8') |
| 1260 | num_bytes_following = (self.SIZE + len(encoded_name) + len(self.salt) + |
| 1261 | len(self.root_digest) - 16) |
| 1262 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1263 | padding_size = nbf_with_padding - num_bytes_following |
| 1264 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 1265 | self.dm_verity_version, self.image_size, |
| 1266 | self.tree_offset, self.tree_size, self.data_block_size, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1267 | self.hash_block_size, self.fec_num_roots, |
| 1268 | self.fec_offset, self.fec_size, self.hash_algorithm, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1269 | len(encoded_name), len(self.salt), len(self.root_digest), |
| 1270 | self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1271 | padding = struct.pack(str(padding_size) + 'x') |
| 1272 | ret = desc + encoded_name + self.salt + self.root_digest + padding |
| 1273 | return bytearray(ret) |
| 1274 | |
| 1275 | |
| 1276 | class AvbHashDescriptor(AvbDescriptor): |
| 1277 | """A class for hash descriptors. |
| 1278 | |
| 1279 | See the |AvbHashDescriptor| C struct for more information. |
| 1280 | |
| 1281 | Attributes: |
| 1282 | image_size: Image size, in bytes. |
| 1283 | hash_algorithm: Hash algorithm used. |
| 1284 | partition_name: Partition name. |
| 1285 | salt: Salt used. |
| 1286 | digest: The hash value of salt and data combined. |
| 1287 | """ |
| 1288 | |
| 1289 | TAG = 2 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1290 | RESERVED = 64 |
| 1291 | SIZE = 68 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1292 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 1293 | 'Q' # image size (bytes) |
| 1294 | '32s' # hash algorithm used |
| 1295 | 'L' # partition name (bytes) |
| 1296 | 'L' # salt length (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1297 | 'L' + # digest length (bytes) |
| 1298 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1299 | |
| 1300 | def __init__(self, data=None): |
| 1301 | """Initializes a new hash descriptor. |
| 1302 | |
| 1303 | Arguments: |
| 1304 | data: If not None, must be a bytearray of size |SIZE|. |
| 1305 | |
| 1306 | Raises: |
| 1307 | LookupError: If the given descriptor is malformed. |
| 1308 | """ |
| 1309 | AvbDescriptor.__init__(self, None) |
| 1310 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1311 | |
| 1312 | if data: |
| 1313 | (tag, num_bytes_following, self.image_size, self.hash_algorithm, |
| 1314 | partition_name_len, salt_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1315 | digest_len, _) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1316 | expected_size = round_to_multiple( |
| 1317 | self.SIZE - 16 + partition_name_len + salt_len + digest_len, 8) |
| 1318 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1319 | raise LookupError('Given data does not look like a hash ' 'descriptor.') |
| 1320 | # Nuke NUL-bytes at the end. |
| 1321 | self.hash_algorithm = self.hash_algorithm.split('\0', 1)[0] |
| 1322 | o = 0 |
| 1323 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1324 | partition_name_len)]) |
| 1325 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1326 | self.partition_name.decode('utf-8') |
| 1327 | o += partition_name_len |
| 1328 | self.salt = data[(self.SIZE + o):(self.SIZE + o + salt_len)] |
| 1329 | o += salt_len |
| 1330 | self.digest = data[(self.SIZE + o):(self.SIZE + o + digest_len)] |
| 1331 | if digest_len != len(hashlib.new(name=self.hash_algorithm).digest()): |
| 1332 | raise LookupError('digest_len doesn\'t match hash algorithm') |
| 1333 | |
| 1334 | else: |
| 1335 | self.image_size = 0 |
| 1336 | self.hash_algorithm = '' |
| 1337 | self.partition_name = '' |
| 1338 | self.salt = bytearray() |
| 1339 | self.digest = bytearray() |
| 1340 | |
| 1341 | def print_desc(self, o): |
| 1342 | """Print the descriptor. |
| 1343 | |
| 1344 | Arguments: |
| 1345 | o: The object to write the output to. |
| 1346 | """ |
| 1347 | o.write(' Hash descriptor:\n') |
| 1348 | o.write(' Image Size: {} bytes\n'.format(self.image_size)) |
| 1349 | o.write(' Hash Algorithm: {}\n'.format(self.hash_algorithm)) |
| 1350 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1351 | o.write(' Salt: {}\n'.format(str(self.salt).encode( |
| 1352 | 'hex'))) |
| 1353 | o.write(' Digest: {}\n'.format(str(self.digest).encode( |
| 1354 | 'hex'))) |
| 1355 | |
| 1356 | def encode(self): |
| 1357 | """Serializes the descriptor. |
| 1358 | |
| 1359 | Returns: |
| 1360 | A bytearray() with the descriptor data. |
| 1361 | """ |
| 1362 | encoded_name = self.partition_name.encode('utf-8') |
| 1363 | num_bytes_following = ( |
| 1364 | self.SIZE + len(encoded_name) + len(self.salt) + len(self.digest) - 16) |
| 1365 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1366 | padding_size = nbf_with_padding - num_bytes_following |
| 1367 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 1368 | self.image_size, self.hash_algorithm, len(encoded_name), |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1369 | len(self.salt), len(self.digest), self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1370 | padding = struct.pack(str(padding_size) + 'x') |
| 1371 | ret = desc + encoded_name + self.salt + self.digest + padding |
| 1372 | return bytearray(ret) |
| 1373 | |
| 1374 | |
| 1375 | class AvbKernelCmdlineDescriptor(AvbDescriptor): |
| 1376 | """A class for kernel command-line descriptors. |
| 1377 | |
| 1378 | See the |AvbKernelCmdlineDescriptor| C struct for more information. |
| 1379 | |
| 1380 | Attributes: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1381 | flags: Flags. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1382 | kernel_cmdline: The kernel command-line. |
| 1383 | """ |
| 1384 | |
| 1385 | TAG = 3 |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1386 | SIZE = 24 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1387 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1388 | 'L' # flags |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1389 | 'L') # cmdline length (bytes) |
| 1390 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1391 | FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED = (1 << 0) |
| 1392 | FLAGS_USE_ONLY_IF_HASHTREE_DISABLED = (1 << 1) |
| 1393 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1394 | def __init__(self, data=None): |
| 1395 | """Initializes a new kernel cmdline descriptor. |
| 1396 | |
| 1397 | Arguments: |
| 1398 | data: If not None, must be a bytearray of size |SIZE|. |
| 1399 | |
| 1400 | Raises: |
| 1401 | LookupError: If the given descriptor is malformed. |
| 1402 | """ |
| 1403 | AvbDescriptor.__init__(self, None) |
| 1404 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1405 | |
| 1406 | if data: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1407 | (tag, num_bytes_following, self.flags, kernel_cmdline_length) = ( |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1408 | struct.unpack(self.FORMAT_STRING, data[0:self.SIZE])) |
| 1409 | expected_size = round_to_multiple(self.SIZE - 16 + kernel_cmdline_length, |
| 1410 | 8) |
| 1411 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1412 | raise LookupError('Given data does not look like a kernel cmdline ' |
| 1413 | 'descriptor.') |
| 1414 | # Nuke NUL-bytes at the end. |
| 1415 | self.kernel_cmdline = str(data[self.SIZE:(self.SIZE + |
| 1416 | kernel_cmdline_length)]) |
| 1417 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1418 | self.kernel_cmdline.decode('utf-8') |
| 1419 | else: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1420 | self.flags = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1421 | self.kernel_cmdline = '' |
| 1422 | |
| 1423 | def print_desc(self, o): |
| 1424 | """Print the descriptor. |
| 1425 | |
| 1426 | Arguments: |
| 1427 | o: The object to write the output to. |
| 1428 | """ |
| 1429 | o.write(' Kernel Cmdline descriptor:\n') |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1430 | o.write(' Flags: {}\n'.format(self.flags)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1431 | o.write(' Kernel Cmdline: {}\n'.format(repr( |
| 1432 | self.kernel_cmdline))) |
| 1433 | |
| 1434 | def encode(self): |
| 1435 | """Serializes the descriptor. |
| 1436 | |
| 1437 | Returns: |
| 1438 | A bytearray() with the descriptor data. |
| 1439 | """ |
| 1440 | encoded_str = self.kernel_cmdline.encode('utf-8') |
| 1441 | num_bytes_following = (self.SIZE + len(encoded_str) - 16) |
| 1442 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1443 | padding_size = nbf_with_padding - num_bytes_following |
| 1444 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1445 | self.flags, len(encoded_str)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1446 | padding = struct.pack(str(padding_size) + 'x') |
| 1447 | ret = desc + encoded_str + padding |
| 1448 | return bytearray(ret) |
| 1449 | |
| 1450 | |
| 1451 | class AvbChainPartitionDescriptor(AvbDescriptor): |
| 1452 | """A class for chained partition descriptors. |
| 1453 | |
| 1454 | See the |AvbChainPartitionDescriptor| C struct for more information. |
| 1455 | |
| 1456 | Attributes: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1457 | rollback_index_location: The rollback index location to use. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1458 | partition_name: Partition name. |
| 1459 | public_key: Bytes for the public key. |
| 1460 | """ |
| 1461 | |
| 1462 | TAG = 4 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1463 | RESERVED = 64 |
| 1464 | SIZE = 28 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1465 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1466 | 'L' # rollback_index_location |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1467 | 'L' # partition_name_size (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1468 | 'L' + # public_key_size (bytes) |
| 1469 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1470 | |
| 1471 | def __init__(self, data=None): |
| 1472 | """Initializes a new chain partition descriptor. |
| 1473 | |
| 1474 | Arguments: |
| 1475 | data: If not None, must be a bytearray of size |SIZE|. |
| 1476 | |
| 1477 | Raises: |
| 1478 | LookupError: If the given descriptor is malformed. |
| 1479 | """ |
| 1480 | AvbDescriptor.__init__(self, None) |
| 1481 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1482 | |
| 1483 | if data: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1484 | (tag, num_bytes_following, self.rollback_index_location, |
| 1485 | partition_name_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1486 | public_key_len, _) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1487 | expected_size = round_to_multiple( |
| 1488 | self.SIZE - 16 + partition_name_len + public_key_len, 8) |
| 1489 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1490 | raise LookupError('Given data does not look like a chain partition ' |
| 1491 | 'descriptor.') |
| 1492 | o = 0 |
| 1493 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1494 | partition_name_len)]) |
| 1495 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1496 | self.partition_name.decode('utf-8') |
| 1497 | o += partition_name_len |
| 1498 | self.public_key = data[(self.SIZE + o):(self.SIZE + o + public_key_len)] |
| 1499 | |
| 1500 | else: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1501 | self.rollback_index_location = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1502 | self.partition_name = '' |
| 1503 | self.public_key = bytearray() |
| 1504 | |
| 1505 | def print_desc(self, o): |
| 1506 | """Print the descriptor. |
| 1507 | |
| 1508 | Arguments: |
| 1509 | o: The object to write the output to. |
| 1510 | """ |
| 1511 | o.write(' Chain Partition descriptor:\n') |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1512 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1513 | o.write(' Rollback Index Location: {}\n'.format( |
| 1514 | self.rollback_index_location)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1515 | # Just show the SHA1 of the key, for size reasons. |
| 1516 | hexdig = hashlib.sha1(self.public_key).hexdigest() |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1517 | o.write(' Public key (sha1): {}\n'.format(hexdig)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1518 | |
| 1519 | def encode(self): |
| 1520 | """Serializes the descriptor. |
| 1521 | |
| 1522 | Returns: |
| 1523 | A bytearray() with the descriptor data. |
| 1524 | """ |
| 1525 | encoded_name = self.partition_name.encode('utf-8') |
| 1526 | num_bytes_following = ( |
| 1527 | self.SIZE + len(encoded_name) + len(self.public_key) - 16) |
| 1528 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1529 | padding_size = nbf_with_padding - num_bytes_following |
| 1530 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1531 | self.rollback_index_location, len(encoded_name), |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1532 | len(self.public_key), self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1533 | padding = struct.pack(str(padding_size) + 'x') |
| 1534 | ret = desc + encoded_name + self.public_key + padding |
| 1535 | return bytearray(ret) |
| 1536 | |
| 1537 | |
| 1538 | DESCRIPTOR_CLASSES = [ |
| 1539 | AvbPropertyDescriptor, AvbHashtreeDescriptor, AvbHashDescriptor, |
| 1540 | AvbKernelCmdlineDescriptor, AvbChainPartitionDescriptor |
| 1541 | ] |
| 1542 | |
| 1543 | |
| 1544 | def parse_descriptors(data): |
| 1545 | """Parses a blob of data into descriptors. |
| 1546 | |
| 1547 | Arguments: |
| 1548 | data: A bytearray() with encoded descriptors. |
| 1549 | |
| 1550 | Returns: |
| 1551 | A list of instances of objects derived from AvbDescriptor. For |
| 1552 | unknown descriptors, the class AvbDescriptor is used. |
| 1553 | """ |
| 1554 | o = 0 |
| 1555 | ret = [] |
| 1556 | while o < len(data): |
| 1557 | tag, nb_following = struct.unpack('!2Q', data[o:o + 16]) |
| 1558 | if tag < len(DESCRIPTOR_CLASSES): |
| 1559 | c = DESCRIPTOR_CLASSES[tag] |
| 1560 | else: |
| 1561 | c = AvbDescriptor |
| 1562 | ret.append(c(bytearray(data[o:o + 16 + nb_following]))) |
| 1563 | o += 16 + nb_following |
| 1564 | return ret |
| 1565 | |
| 1566 | |
| 1567 | class AvbFooter(object): |
| 1568 | """A class for parsing and writing footers. |
| 1569 | |
| 1570 | Footers are stored at the end of partitions and point to where the |
| 1571 | AvbVBMeta blob is located. They also contain the original size of |
| 1572 | the image before AVB information was added. |
| 1573 | |
| 1574 | Attributes: |
| 1575 | magic: Magic for identifying the footer, see |MAGIC|. |
| 1576 | version_major: The major version of avbtool that wrote the footer. |
| 1577 | version_minor: The minor version of avbtool that wrote the footer. |
| 1578 | original_image_size: Original image size. |
| 1579 | vbmeta_offset: Offset of where the AvbVBMeta blob is stored. |
| 1580 | vbmeta_size: Size of the AvbVBMeta blob. |
| 1581 | """ |
| 1582 | |
| 1583 | MAGIC = 'AVBf' |
| 1584 | SIZE = 64 |
| 1585 | RESERVED = 28 |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1586 | FOOTER_VERSION_MAJOR = 1 |
| 1587 | FOOTER_VERSION_MINOR = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1588 | FORMAT_STRING = ('!4s2L' # magic, 2 x version. |
| 1589 | 'Q' # Original image size. |
| 1590 | 'Q' # Offset of VBMeta blob. |
| 1591 | 'Q' + # Size of VBMeta blob. |
| 1592 | str(RESERVED) + 'x') # padding for reserved bytes |
| 1593 | |
| 1594 | def __init__(self, data=None): |
| 1595 | """Initializes a new footer object. |
| 1596 | |
| 1597 | Arguments: |
| 1598 | data: If not None, must be a bytearray of size 4096. |
| 1599 | |
| 1600 | Raises: |
| 1601 | LookupError: If the given footer is malformed. |
| 1602 | struct.error: If the given data has no footer. |
| 1603 | """ |
| 1604 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1605 | |
| 1606 | if data: |
| 1607 | (self.magic, self.version_major, self.version_minor, |
| 1608 | self.original_image_size, self.vbmeta_offset, |
| 1609 | self.vbmeta_size) = struct.unpack(self.FORMAT_STRING, data) |
| 1610 | if self.magic != self.MAGIC: |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1611 | raise LookupError('Given data does not look like a AVB footer.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1612 | else: |
| 1613 | self.magic = self.MAGIC |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1614 | self.version_major = self.FOOTER_VERSION_MAJOR |
| 1615 | self.version_minor = self.FOOTER_VERSION_MINOR |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1616 | self.original_image_size = 0 |
| 1617 | self.vbmeta_offset = 0 |
| 1618 | self.vbmeta_size = 0 |
| 1619 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1620 | def encode(self): |
| 1621 | """Gets a string representing the binary encoding of the footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1622 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1623 | Returns: |
| 1624 | A bytearray() with a binary representation of the footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1625 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1626 | return struct.pack(self.FORMAT_STRING, self.magic, self.version_major, |
| 1627 | self.version_minor, self.original_image_size, |
| 1628 | self.vbmeta_offset, self.vbmeta_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1629 | |
| 1630 | |
| 1631 | class AvbVBMetaHeader(object): |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1632 | """A class for parsing and writing AVB vbmeta images. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1633 | |
| 1634 | Attributes: |
| 1635 | The attributes correspond to the |AvbVBMetaHeader| struct |
| 1636 | defined in avb_vbmeta_header.h. |
| 1637 | """ |
| 1638 | |
| 1639 | SIZE = 256 |
| 1640 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1641 | # Keep in sync with |reserved0| and |reserved| field of |
| 1642 | # |AvbVBMetaImageHeader|. |
| 1643 | RESERVED0 = 4 |
| 1644 | RESERVED = 80 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1645 | |
| 1646 | # Keep in sync with |AvbVBMetaImageHeader|. |
| 1647 | FORMAT_STRING = ('!4s2L' # magic, 2 x version |
| 1648 | '2Q' # 2 x block size |
| 1649 | 'L' # algorithm type |
| 1650 | '2Q' # offset, size (hash) |
| 1651 | '2Q' # offset, size (signature) |
| 1652 | '2Q' # offset, size (public key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1653 | '2Q' # offset, size (public key metadata) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1654 | '2Q' # offset, size (descriptors) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1655 | 'Q' # rollback_index |
| 1656 | 'L' + # flags |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1657 | str(RESERVED0) + 'x' + # padding for reserved bytes |
| 1658 | '47sx' + # NUL-terminated release string |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1659 | str(RESERVED) + 'x') # padding for reserved bytes |
| 1660 | |
| 1661 | def __init__(self, data=None): |
| 1662 | """Initializes a new header object. |
| 1663 | |
| 1664 | Arguments: |
| 1665 | data: If not None, must be a bytearray of size 8192. |
| 1666 | |
| 1667 | Raises: |
| 1668 | Exception: If the given data is malformed. |
| 1669 | """ |
| 1670 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1671 | |
| 1672 | if data: |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1673 | (self.magic, self.required_libavb_version_major, |
| 1674 | self.required_libavb_version_minor, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1675 | self.authentication_data_block_size, self.auxiliary_data_block_size, |
| 1676 | self.algorithm_type, self.hash_offset, self.hash_size, |
| 1677 | self.signature_offset, self.signature_size, self.public_key_offset, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1678 | self.public_key_size, self.public_key_metadata_offset, |
| 1679 | self.public_key_metadata_size, self.descriptors_offset, |
| 1680 | self.descriptors_size, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1681 | self.rollback_index, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1682 | self.flags, |
| 1683 | self.release_string) = struct.unpack(self.FORMAT_STRING, data) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1684 | # Nuke NUL-bytes at the end of the string. |
| 1685 | if self.magic != 'AVB0': |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1686 | raise AvbError('Given image does not look like a vbmeta image.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1687 | else: |
| 1688 | self.magic = 'AVB0' |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1689 | # Start by just requiring version 1.0. Code that adds features |
| 1690 | # in a future version can use bump_required_libavb_version_minor() to |
| 1691 | # bump the minor. |
| 1692 | self.required_libavb_version_major = AVB_VERSION_MAJOR |
| 1693 | self.required_libavb_version_minor = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1694 | self.authentication_data_block_size = 0 |
| 1695 | self.auxiliary_data_block_size = 0 |
| 1696 | self.algorithm_type = 0 |
| 1697 | self.hash_offset = 0 |
| 1698 | self.hash_size = 0 |
| 1699 | self.signature_offset = 0 |
| 1700 | self.signature_size = 0 |
| 1701 | self.public_key_offset = 0 |
| 1702 | self.public_key_size = 0 |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1703 | self.public_key_metadata_offset = 0 |
| 1704 | self.public_key_metadata_size = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1705 | self.descriptors_offset = 0 |
| 1706 | self.descriptors_size = 0 |
| 1707 | self.rollback_index = 0 |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1708 | self.flags = 0 |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1709 | self.release_string = get_release_string() |
| 1710 | |
| 1711 | def bump_required_libavb_version_minor(self, minor): |
| 1712 | """Function to bump required_libavb_version_minor. |
| 1713 | |
| 1714 | Call this when writing data that requires a specific libavb |
| 1715 | version to parse it. |
| 1716 | |
| 1717 | Arguments: |
| 1718 | minor: The minor version of libavb that has support for the feature. |
| 1719 | """ |
| 1720 | self.required_libavb_version_minor = ( |
| 1721 | min(self.required_libavb_version_minor, minor)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1722 | |
| 1723 | def save(self, output): |
| 1724 | """Serializes the header (256 bytes) to disk. |
| 1725 | |
| 1726 | Arguments: |
| 1727 | output: The object to write the output to. |
| 1728 | """ |
| 1729 | output.write(struct.pack( |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1730 | self.FORMAT_STRING, self.magic, self.required_libavb_version_major, |
| 1731 | self.required_libavb_version_minor, self.authentication_data_block_size, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1732 | self.auxiliary_data_block_size, self.algorithm_type, self.hash_offset, |
| 1733 | self.hash_size, self.signature_offset, self.signature_size, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1734 | self.public_key_offset, self.public_key_size, |
| 1735 | self.public_key_metadata_offset, self.public_key_metadata_size, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1736 | self.descriptors_offset, self.descriptors_size, self.rollback_index, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1737 | self.flags, self.release_string)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1738 | |
| 1739 | def encode(self): |
| 1740 | """Serializes the header (256) to a bytearray(). |
| 1741 | |
| 1742 | Returns: |
| 1743 | A bytearray() with the encoded header. |
| 1744 | """ |
| 1745 | return struct.pack(self.FORMAT_STRING, self.magic, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1746 | self.required_libavb_version_major, |
| 1747 | self.required_libavb_version_minor, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1748 | self.authentication_data_block_size, |
| 1749 | self.auxiliary_data_block_size, self.algorithm_type, |
| 1750 | self.hash_offset, self.hash_size, self.signature_offset, |
| 1751 | self.signature_size, self.public_key_offset, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1752 | self.public_key_size, self.public_key_metadata_offset, |
| 1753 | self.public_key_metadata_size, self.descriptors_offset, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1754 | self.descriptors_size, self.rollback_index, self.flags, |
| 1755 | self.release_string) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1756 | |
| 1757 | |
| 1758 | class Avb(object): |
| 1759 | """Business logic for avbtool command-line tool.""" |
| 1760 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1761 | # Keep in sync with avb_ab_flow.h. |
| 1762 | AB_FORMAT_NO_CRC = '!4sBB2xBBBxBBBx12x' |
| 1763 | AB_MAGIC = '\0AB0' |
| 1764 | AB_MAJOR_VERSION = 1 |
| 1765 | AB_MINOR_VERSION = 0 |
| 1766 | AB_MISC_METADATA_OFFSET = 2048 |
| 1767 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 1768 | # Constants for maximum metadata size. These are used to give |
| 1769 | # meaningful errors if the value passed in via --partition_size is |
| 1770 | # too small and when --calc_max_image_size is used. We use |
| 1771 | # conservative figures. |
| 1772 | MAX_VBMETA_SIZE = 64 * 1024 |
| 1773 | MAX_FOOTER_SIZE = 4096 |
| 1774 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1775 | def erase_footer(self, image_filename, keep_hashtree): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1776 | """Implements the 'erase_footer' command. |
| 1777 | |
| 1778 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1779 | image_filename: File to erase a footer from. |
David Zeuthen | fbb61fa | 2017-02-02 12:11:49 -0500 | [diff] [blame] | 1780 | keep_hashtree: If True, keep the hashtree and FEC around. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1781 | |
| 1782 | Raises: |
| 1783 | AvbError: If there's no footer in the image. |
| 1784 | """ |
| 1785 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1786 | image = ImageHandler(image_filename) |
| 1787 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1788 | (footer, _, descriptors, _) = self._parse_image(image) |
| 1789 | |
| 1790 | if not footer: |
| 1791 | raise AvbError('Given image does not have a footer.') |
| 1792 | |
| 1793 | new_image_size = None |
| 1794 | if not keep_hashtree: |
| 1795 | new_image_size = footer.original_image_size |
| 1796 | else: |
| 1797 | # If requested to keep the hashtree, search for a hashtree |
David Zeuthen | fbb61fa | 2017-02-02 12:11:49 -0500 | [diff] [blame] | 1798 | # descriptor to figure out the location and size of the hashtree |
| 1799 | # and FEC. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1800 | for desc in descriptors: |
| 1801 | if isinstance(desc, AvbHashtreeDescriptor): |
| 1802 | # The hashtree is always just following the main data so the |
| 1803 | # new size is easily derived. |
| 1804 | new_image_size = desc.tree_offset + desc.tree_size |
David Zeuthen | fbb61fa | 2017-02-02 12:11:49 -0500 | [diff] [blame] | 1805 | # If the image has FEC codes, also keep those. |
| 1806 | if desc.fec_offset > 0: |
| 1807 | fec_end = desc.fec_offset + desc.fec_size |
| 1808 | new_image_size = max(new_image_size, fec_end) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1809 | break |
| 1810 | if not new_image_size: |
| 1811 | raise AvbError('Requested to keep hashtree but no hashtree ' |
| 1812 | 'descriptor was found.') |
| 1813 | |
| 1814 | # And cut... |
| 1815 | image.truncate(new_image_size) |
| 1816 | |
David Zeuthen | 2bc232b | 2017-04-19 14:25:19 -0400 | [diff] [blame] | 1817 | def resize_image(self, image_filename, partition_size): |
| 1818 | """Implements the 'resize_image' command. |
| 1819 | |
| 1820 | Arguments: |
| 1821 | image_filename: File with footer to resize. |
| 1822 | partition_size: The new size of the image. |
| 1823 | |
| 1824 | Raises: |
| 1825 | AvbError: If there's no footer in the image. |
| 1826 | """ |
| 1827 | |
| 1828 | image = ImageHandler(image_filename) |
| 1829 | |
| 1830 | if partition_size % image.block_size != 0: |
| 1831 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 1832 | 'block size {}.'.format(partition_size, |
| 1833 | image.block_size)) |
| 1834 | |
| 1835 | (footer, vbmeta_header, descriptors, _) = self._parse_image(image) |
| 1836 | |
| 1837 | if not footer: |
| 1838 | raise AvbError('Given image does not have a footer.') |
| 1839 | |
| 1840 | # The vbmeta blob is always at the end of the data so resizing an |
| 1841 | # image amounts to just moving the footer around. |
| 1842 | |
| 1843 | vbmeta_end_offset = footer.vbmeta_offset + footer.vbmeta_size |
| 1844 | if vbmeta_end_offset % image.block_size != 0: |
| 1845 | vbmeta_end_offset += image.block_size - (vbmeta_end_offset % image.block_size) |
| 1846 | |
| 1847 | if partition_size < vbmeta_end_offset + 1*image.block_size: |
| 1848 | raise AvbError('Requested size of {} is too small for an image ' |
| 1849 | 'of size {}.' |
| 1850 | .format(partition_size, |
| 1851 | vbmeta_end_offset + 1*image.block_size)) |
| 1852 | |
| 1853 | # Cut at the end of the vbmeta blob and insert a DONT_CARE chunk |
| 1854 | # with enough bytes such that the final Footer block is at the end |
| 1855 | # of partition_size. |
| 1856 | image.truncate(vbmeta_end_offset) |
| 1857 | image.append_dont_care(partition_size - vbmeta_end_offset - |
| 1858 | 1*image.block_size) |
| 1859 | |
| 1860 | # Just reuse the same footer - only difference is that we're |
| 1861 | # writing it in a different place. |
| 1862 | footer_blob = footer.encode() |
| 1863 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 1864 | footer_blob) |
| 1865 | image.append_raw(footer_blob_with_padding) |
| 1866 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1867 | def set_ab_metadata(self, misc_image, slot_data): |
| 1868 | """Implements the 'set_ab_metadata' command. |
| 1869 | |
| 1870 | The |slot_data| argument must be of the form 'A_priority:A_tries_remaining: |
| 1871 | A_successful_boot:B_priority:B_tries_remaining:B_successful_boot'. |
| 1872 | |
| 1873 | Arguments: |
| 1874 | misc_image: The misc image to write to. |
| 1875 | slot_data: Slot data as a string |
| 1876 | |
| 1877 | Raises: |
| 1878 | AvbError: If slot data is malformed. |
| 1879 | """ |
| 1880 | tokens = slot_data.split(':') |
| 1881 | if len(tokens) != 6: |
| 1882 | raise AvbError('Malformed slot data "{}".'.format(slot_data)) |
| 1883 | a_priority = int(tokens[0]) |
| 1884 | a_tries_remaining = int(tokens[1]) |
| 1885 | a_success = True if int(tokens[2]) != 0 else False |
| 1886 | b_priority = int(tokens[3]) |
| 1887 | b_tries_remaining = int(tokens[4]) |
| 1888 | b_success = True if int(tokens[5]) != 0 else False |
| 1889 | |
| 1890 | ab_data_no_crc = struct.pack(self.AB_FORMAT_NO_CRC, |
| 1891 | self.AB_MAGIC, |
| 1892 | self.AB_MAJOR_VERSION, self.AB_MINOR_VERSION, |
| 1893 | a_priority, a_tries_remaining, a_success, |
| 1894 | b_priority, b_tries_remaining, b_success) |
| 1895 | # Force CRC to be unsigned, see https://bugs.python.org/issue4903 for why. |
| 1896 | crc_value = binascii.crc32(ab_data_no_crc) & 0xffffffff |
| 1897 | ab_data = ab_data_no_crc + struct.pack('!I', crc_value) |
| 1898 | misc_image.seek(self.AB_MISC_METADATA_OFFSET) |
| 1899 | misc_image.write(ab_data) |
| 1900 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1901 | def info_image(self, image_filename, output): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1902 | """Implements the 'info_image' command. |
| 1903 | |
| 1904 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1905 | image_filename: Image file to get information from (file object). |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1906 | output: Output file to write human-readable information to (file object). |
| 1907 | """ |
| 1908 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1909 | image = ImageHandler(image_filename) |
| 1910 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1911 | o = output |
| 1912 | |
| 1913 | (footer, header, descriptors, image_size) = self._parse_image(image) |
| 1914 | |
| 1915 | if footer: |
| 1916 | o.write('Footer version: {}.{}\n'.format(footer.version_major, |
| 1917 | footer.version_minor)) |
| 1918 | o.write('Image size: {} bytes\n'.format(image_size)) |
| 1919 | o.write('Original image size: {} bytes\n'.format( |
| 1920 | footer.original_image_size)) |
| 1921 | o.write('VBMeta offset: {}\n'.format(footer.vbmeta_offset)) |
| 1922 | o.write('VBMeta size: {} bytes\n'.format(footer.vbmeta_size)) |
| 1923 | o.write('--\n') |
| 1924 | |
| 1925 | (alg_name, _) = lookup_algorithm_by_type(header.algorithm_type) |
| 1926 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1927 | o.write('Minimum libavb version: {}.{}{}\n'.format( |
| 1928 | header.required_libavb_version_major, |
| 1929 | header.required_libavb_version_minor, |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1930 | ' (Sparse)' if image.is_sparse else '')) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1931 | o.write('Header Block: {} bytes\n'.format(AvbVBMetaHeader.SIZE)) |
| 1932 | o.write('Authentication Block: {} bytes\n'.format( |
| 1933 | header.authentication_data_block_size)) |
| 1934 | o.write('Auxiliary Block: {} bytes\n'.format( |
| 1935 | header.auxiliary_data_block_size)) |
| 1936 | o.write('Algorithm: {}\n'.format(alg_name)) |
| 1937 | o.write('Rollback Index: {}\n'.format(header.rollback_index)) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1938 | o.write('Flags: {}\n'.format(header.flags)) |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 1939 | o.write('Release String: \'{}\'\n'.format( |
| 1940 | header.release_string.rstrip('\0'))) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1941 | |
| 1942 | # Print descriptors. |
| 1943 | num_printed = 0 |
| 1944 | o.write('Descriptors:\n') |
| 1945 | for desc in descriptors: |
| 1946 | desc.print_desc(o) |
| 1947 | num_printed += 1 |
| 1948 | if num_printed == 0: |
| 1949 | o.write(' (none)\n') |
| 1950 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 1951 | def verify_image(self, image_filename): |
| 1952 | """Implements the 'verify_image' command. |
| 1953 | |
| 1954 | Arguments: |
| 1955 | image_filename: Image file to get information from (file object). |
| 1956 | """ |
| 1957 | |
| 1958 | image = ImageHandler(image_filename) |
| 1959 | (footer, header, descriptors, image_size) = self._parse_image(image) |
| 1960 | offset = 0 |
| 1961 | if footer: |
| 1962 | offset = footer.vbmeta_offset |
| 1963 | size = (header.SIZE + header.authentication_data_block_size + |
| 1964 | header.auxiliary_data_block_size) |
| 1965 | image.seek(offset) |
| 1966 | vbmeta_blob = image.read(size) |
| 1967 | if not verify_vbmeta_signature(header, vbmeta_blob): |
| 1968 | raise AvbError('Signature check failed.') |
| 1969 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1970 | def _parse_image(self, image): |
| 1971 | """Gets information about an image. |
| 1972 | |
| 1973 | The image can either be a vbmeta or an image with a footer. |
| 1974 | |
| 1975 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1976 | image: An ImageHandler (vbmeta or footer) with a hashtree descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1977 | |
| 1978 | Returns: |
| 1979 | A tuple where the first argument is a AvbFooter (None if there |
| 1980 | is no footer on the image), the second argument is a |
| 1981 | AvbVBMetaHeader, the third argument is a list of |
| 1982 | AvbDescriptor-derived instances, and the fourth argument is the |
| 1983 | size of |image|. |
| 1984 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1985 | assert isinstance(image, ImageHandler) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1986 | footer = None |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 1987 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1988 | try: |
| 1989 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 1990 | except (LookupError, struct.error): |
| 1991 | # Nope, just seek back to the start. |
| 1992 | image.seek(0) |
| 1993 | |
| 1994 | vbmeta_offset = 0 |
| 1995 | if footer: |
| 1996 | vbmeta_offset = footer.vbmeta_offset |
| 1997 | |
| 1998 | image.seek(vbmeta_offset) |
| 1999 | h = AvbVBMetaHeader(image.read(AvbVBMetaHeader.SIZE)) |
| 2000 | |
| 2001 | auth_block_offset = vbmeta_offset + AvbVBMetaHeader.SIZE |
| 2002 | aux_block_offset = auth_block_offset + h.authentication_data_block_size |
| 2003 | desc_start_offset = aux_block_offset + h.descriptors_offset |
| 2004 | image.seek(desc_start_offset) |
| 2005 | descriptors = parse_descriptors(image.read(h.descriptors_size)) |
| 2006 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2007 | return footer, h, descriptors, image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2008 | |
David Zeuthen | b1b994d | 2017-03-06 18:01:31 -0500 | [diff] [blame] | 2009 | def _load_vbmeta_blob(self, image): |
| 2010 | """Gets the vbmeta struct and associated sections. |
| 2011 | |
| 2012 | The image can either be a vbmeta.img or an image with a footer. |
| 2013 | |
| 2014 | Arguments: |
| 2015 | image: An ImageHandler (vbmeta or footer). |
| 2016 | |
| 2017 | Returns: |
| 2018 | A blob with the vbmeta struct and other sections. |
| 2019 | """ |
| 2020 | assert isinstance(image, ImageHandler) |
| 2021 | footer = None |
| 2022 | image.seek(image.image_size - AvbFooter.SIZE) |
| 2023 | try: |
| 2024 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2025 | except (LookupError, struct.error): |
| 2026 | # Nope, just seek back to the start. |
| 2027 | image.seek(0) |
| 2028 | |
| 2029 | vbmeta_offset = 0 |
| 2030 | if footer: |
| 2031 | vbmeta_offset = footer.vbmeta_offset |
| 2032 | |
| 2033 | image.seek(vbmeta_offset) |
| 2034 | h = AvbVBMetaHeader(image.read(AvbVBMetaHeader.SIZE)) |
| 2035 | |
| 2036 | image.seek(vbmeta_offset) |
| 2037 | data_size = AvbVBMetaHeader.SIZE |
| 2038 | data_size += h.authentication_data_block_size |
| 2039 | data_size += h.auxiliary_data_block_size |
| 2040 | return image.read(data_size) |
| 2041 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2042 | def _get_cmdline_descriptors_for_dm_verity(self, image): |
| 2043 | """Generate kernel cmdline descriptors for dm-verity. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2044 | |
| 2045 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2046 | image: An ImageHandler (vbmeta or footer) with a hashtree descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2047 | |
| 2048 | Returns: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2049 | A list with two AvbKernelCmdlineDescriptor with dm-verity kernel cmdline |
| 2050 | instructions. There is one for when hashtree is not disabled and one for |
| 2051 | when it is. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2052 | |
| 2053 | Raises: |
| 2054 | AvbError: If |image| doesn't have a hashtree descriptor. |
| 2055 | |
| 2056 | """ |
| 2057 | |
| 2058 | (_, _, descriptors, _) = self._parse_image(image) |
| 2059 | |
| 2060 | ht = None |
| 2061 | for desc in descriptors: |
| 2062 | if isinstance(desc, AvbHashtreeDescriptor): |
| 2063 | ht = desc |
| 2064 | break |
| 2065 | |
| 2066 | if not ht: |
| 2067 | raise AvbError('No hashtree descriptor in given image') |
| 2068 | |
| 2069 | c = 'dm="1 vroot none ro 1,' |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2070 | c += '0' # start |
| 2071 | c += ' {}'.format((ht.image_size / 512)) # size (# sectors) |
| 2072 | c += ' verity {}'.format(ht.dm_verity_version) # type and version |
| 2073 | c += ' PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' # data_dev |
| 2074 | c += ' PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' # hash_dev |
| 2075 | c += ' {}'.format(ht.data_block_size) # data_block |
| 2076 | c += ' {}'.format(ht.hash_block_size) # hash_block |
| 2077 | c += ' {}'.format(ht.image_size / ht.data_block_size) # #blocks |
| 2078 | c += ' {}'.format(ht.image_size / ht.data_block_size) # hash_offset |
| 2079 | c += ' {}'.format(ht.hash_algorithm) # hash_alg |
| 2080 | c += ' {}'.format(str(ht.root_digest).encode('hex')) # root_digest |
| 2081 | c += ' {}'.format(str(ht.salt).encode('hex')) # salt |
| 2082 | if ht.fec_num_roots > 0: |
David Zeuthen | a01e32f | 2017-01-24 17:32:38 -0500 | [diff] [blame] | 2083 | c += ' 10' # number of optional args |
| 2084 | c += ' restart_on_corruption' |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2085 | c += ' ignore_zero_blocks' |
| 2086 | c += ' use_fec_from_device PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' |
| 2087 | c += ' fec_roots {}'.format(ht.fec_num_roots) |
| 2088 | # Note that fec_blocks is the size that FEC covers, *not* the |
| 2089 | # size of the FEC data. Since we use FEC for everything up until |
| 2090 | # the FEC data, it's the same as the offset. |
| 2091 | c += ' fec_blocks {}'.format(ht.fec_offset/ht.data_block_size) |
| 2092 | c += ' fec_start {}'.format(ht.fec_offset/ht.data_block_size) |
| 2093 | else: |
David Zeuthen | a01e32f | 2017-01-24 17:32:38 -0500 | [diff] [blame] | 2094 | c += ' 2' # number of optional args |
| 2095 | c += ' restart_on_corruption' |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2096 | c += ' ignore_zero_blocks' |
David Zeuthen | fd9c18d | 2017-03-20 18:19:30 -0400 | [diff] [blame] | 2097 | c += '" root=/dev/dm-0' |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2098 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2099 | # Now that we have the command-line, generate the descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2100 | desc = AvbKernelCmdlineDescriptor() |
| 2101 | desc.kernel_cmdline = c |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2102 | desc.flags = ( |
| 2103 | AvbKernelCmdlineDescriptor.FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) |
| 2104 | |
| 2105 | # The descriptor for when hashtree verification is disabled is a lot |
| 2106 | # simpler - we just set the root to the partition. |
| 2107 | desc_no_ht = AvbKernelCmdlineDescriptor() |
| 2108 | desc_no_ht.kernel_cmdline = 'root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' |
| 2109 | desc_no_ht.flags = ( |
| 2110 | AvbKernelCmdlineDescriptor.FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) |
| 2111 | |
| 2112 | return [desc, desc_no_ht] |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2113 | |
| 2114 | def make_vbmeta_image(self, output, chain_partitions, algorithm_name, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2115 | key_path, public_key_metadata_path, rollback_index, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2116 | flags, props, props_from_file, kernel_cmdlines, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2117 | setup_rootfs_from_kernel, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2118 | include_descriptors_from_image, signing_helper, |
| 2119 | release_string, |
| 2120 | append_to_release_string): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2121 | """Implements the 'make_vbmeta_image' command. |
| 2122 | |
| 2123 | Arguments: |
| 2124 | output: File to write the image to. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2125 | chain_partitions: List of partitions to chain or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2126 | algorithm_name: Name of algorithm to use. |
| 2127 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2128 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2129 | rollback_index: The rollback index to use. |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2130 | flags: Flags value to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2131 | props: Properties to insert (list of strings of the form 'key:value'). |
| 2132 | props_from_file: Properties to insert (list of strings 'key:<path>'). |
| 2133 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2134 | setup_rootfs_from_kernel: None or file to generate from. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2135 | include_descriptors_from_image: List of file objects with descriptors. |
Dzmitry Yatsushkevich | 4e55279 | 2016-12-15 10:27:48 -0800 | [diff] [blame] | 2136 | signing_helper: Program which signs a hash and return signature. |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2137 | release_string: None or avbtool release string to use instead of default. |
| 2138 | append_to_release_string: None or string to append. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2139 | |
| 2140 | Raises: |
| 2141 | AvbError: If a chained partition is malformed. |
| 2142 | """ |
| 2143 | |
| 2144 | descriptors = [] |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2145 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2146 | algorithm_name, key_path, public_key_metadata_path, descriptors, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2147 | chain_partitions, rollback_index, flags, props, props_from_file, |
| 2148 | kernel_cmdlines, setup_rootfs_from_kernel, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2149 | include_descriptors_from_image, signing_helper, release_string, |
| 2150 | append_to_release_string) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2151 | |
| 2152 | # Write entire vbmeta blob (header, authentication, auxiliary). |
| 2153 | output.seek(0) |
| 2154 | output.write(vbmeta_blob) |
| 2155 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2156 | def _generate_vbmeta_blob(self, algorithm_name, key_path, |
| 2157 | public_key_metadata_path, descriptors, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2158 | chain_partitions, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2159 | rollback_index, flags, props, props_from_file, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2160 | kernel_cmdlines, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2161 | setup_rootfs_from_kernel, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2162 | include_descriptors_from_image, signing_helper, |
| 2163 | release_string, append_to_release_string): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2164 | """Generates a VBMeta blob. |
| 2165 | |
| 2166 | This blob contains the header (struct AvbVBMetaHeader), the |
| 2167 | authentication data block (which contains the hash and signature |
| 2168 | for the header and auxiliary block), and the auxiliary block |
| 2169 | (which contains descriptors, the public key used, and other data). |
| 2170 | |
| 2171 | The |key| parameter can |None| only if the |algorithm_name| is |
| 2172 | 'NONE'. |
| 2173 | |
| 2174 | Arguments: |
| 2175 | algorithm_name: The algorithm name as per the ALGORITHMS dict. |
| 2176 | key_path: The path to the .pem file used to sign the blob. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2177 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2178 | descriptors: A list of descriptors to insert or None. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2179 | chain_partitions: List of partitions to chain or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2180 | rollback_index: The rollback index to use. |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2181 | flags: Flags to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2182 | props: Properties to insert (List of strings of the form 'key:value'). |
| 2183 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 2184 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2185 | setup_rootfs_from_kernel: None or file to generate |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2186 | dm-verity kernel cmdline from. |
| 2187 | include_descriptors_from_image: List of file objects for which |
| 2188 | to insert descriptors from. |
Dzmitry Yatsushkevich | 4e55279 | 2016-12-15 10:27:48 -0800 | [diff] [blame] | 2189 | signing_helper: Program which signs a hash and return signature. |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2190 | release_string: None or avbtool release string. |
| 2191 | append_to_release_string: None or string to append. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2192 | |
| 2193 | Returns: |
| 2194 | A bytearray() with the VBMeta blob. |
| 2195 | |
| 2196 | Raises: |
| 2197 | Exception: If the |algorithm_name| is not found, if no key has |
| 2198 | been given and the given algorithm requires one, or the key is |
| 2199 | of the wrong size. |
| 2200 | |
| 2201 | """ |
| 2202 | try: |
| 2203 | alg = ALGORITHMS[algorithm_name] |
| 2204 | except KeyError: |
| 2205 | raise AvbError('Unknown algorithm with name {}'.format(algorithm_name)) |
| 2206 | |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2207 | if not descriptors: |
| 2208 | descriptors = [] |
| 2209 | |
| 2210 | # Insert chained partition descriptors, if any |
| 2211 | if chain_partitions: |
| 2212 | for cp in chain_partitions: |
| 2213 | cp_tokens = cp.split(':') |
| 2214 | if len(cp_tokens) != 3: |
| 2215 | raise AvbError('Malformed chained partition "{}".'.format(cp)) |
| 2216 | desc = AvbChainPartitionDescriptor() |
| 2217 | desc.partition_name = cp_tokens[0] |
| 2218 | desc.rollback_index_location = int(cp_tokens[1]) |
| 2219 | if desc.rollback_index_location < 1: |
| 2220 | raise AvbError('Rollback index location must be 1 or larger.') |
| 2221 | file_path = cp_tokens[2] |
| 2222 | desc.public_key = open(file_path, 'rb').read() |
| 2223 | descriptors.append(desc) |
| 2224 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2225 | # Descriptors. |
| 2226 | encoded_descriptors = bytearray() |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2227 | for desc in descriptors: |
| 2228 | encoded_descriptors.extend(desc.encode()) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2229 | |
| 2230 | # Add properties. |
| 2231 | if props: |
| 2232 | for prop in props: |
| 2233 | idx = prop.find(':') |
| 2234 | if idx == -1: |
| 2235 | raise AvbError('Malformed property "{}".'.format(prop)) |
| 2236 | desc = AvbPropertyDescriptor() |
| 2237 | desc.key = prop[0:idx] |
| 2238 | desc.value = prop[(idx + 1):] |
| 2239 | encoded_descriptors.extend(desc.encode()) |
| 2240 | if props_from_file: |
| 2241 | for prop in props_from_file: |
| 2242 | idx = prop.find(':') |
| 2243 | if idx == -1: |
| 2244 | raise AvbError('Malformed property "{}".'.format(prop)) |
| 2245 | desc = AvbPropertyDescriptor() |
| 2246 | desc.key = prop[0:idx] |
| 2247 | desc.value = prop[(idx + 1):] |
| 2248 | file_path = prop[(idx + 1):] |
| 2249 | desc.value = open(file_path, 'rb').read() |
| 2250 | encoded_descriptors.extend(desc.encode()) |
| 2251 | |
| 2252 | # Add AvbKernelCmdline descriptor for dm-verity, if requested. |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2253 | if setup_rootfs_from_kernel: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2254 | image_handler = ImageHandler( |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2255 | setup_rootfs_from_kernel.name) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2256 | cmdline_desc = self._get_cmdline_descriptors_for_dm_verity(image_handler) |
| 2257 | encoded_descriptors.extend(cmdline_desc[0].encode()) |
| 2258 | encoded_descriptors.extend(cmdline_desc[1].encode()) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2259 | |
| 2260 | # Add kernel command-lines. |
| 2261 | if kernel_cmdlines: |
| 2262 | for i in kernel_cmdlines: |
| 2263 | desc = AvbKernelCmdlineDescriptor() |
| 2264 | desc.kernel_cmdline = i |
| 2265 | encoded_descriptors.extend(desc.encode()) |
| 2266 | |
| 2267 | # Add descriptors from other images. |
| 2268 | if include_descriptors_from_image: |
| 2269 | for image in include_descriptors_from_image: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2270 | image_handler = ImageHandler(image.name) |
| 2271 | (_, _, image_descriptors, _) = self._parse_image(image_handler) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2272 | for desc in image_descriptors: |
| 2273 | encoded_descriptors.extend(desc.encode()) |
| 2274 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2275 | # Load public key metadata blob, if requested. |
| 2276 | pkmd_blob = [] |
| 2277 | if public_key_metadata_path: |
| 2278 | with open(public_key_metadata_path) as f: |
| 2279 | pkmd_blob = f.read() |
| 2280 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2281 | key = None |
| 2282 | encoded_key = bytearray() |
| 2283 | if alg.public_key_num_bytes > 0: |
| 2284 | if not key_path: |
| 2285 | raise AvbError('Key is required for algorithm {}'.format( |
| 2286 | algorithm_name)) |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2287 | encoded_key = encode_rsa_key(key_path) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2288 | if len(encoded_key) != alg.public_key_num_bytes: |
| 2289 | raise AvbError('Key is wrong size for algorithm {}'.format( |
| 2290 | algorithm_name)) |
| 2291 | |
| 2292 | h = AvbVBMetaHeader() |
| 2293 | |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2294 | # Override release string, if requested. |
| 2295 | if isinstance(release_string, (str, unicode)): |
| 2296 | h.release_string = release_string |
| 2297 | |
| 2298 | # Append to release string, if requested. Also insert a space before. |
| 2299 | if isinstance(append_to_release_string, (str, unicode)): |
| 2300 | h.release_string += ' ' + append_to_release_string |
| 2301 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2302 | # For the Auxiliary data block, descriptors are stored at offset 0, |
| 2303 | # followed by the public key, followed by the public key metadata blob. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2304 | h.auxiliary_data_block_size = round_to_multiple( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2305 | len(encoded_descriptors) + len(encoded_key) + len(pkmd_blob), 64) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2306 | h.descriptors_offset = 0 |
| 2307 | h.descriptors_size = len(encoded_descriptors) |
| 2308 | h.public_key_offset = h.descriptors_size |
| 2309 | h.public_key_size = len(encoded_key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2310 | h.public_key_metadata_offset = h.public_key_offset + h.public_key_size |
| 2311 | h.public_key_metadata_size = len(pkmd_blob) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2312 | |
| 2313 | # For the Authentication data block, the hash is first and then |
| 2314 | # the signature. |
| 2315 | h.authentication_data_block_size = round_to_multiple( |
David Zeuthen | d5db21d | 2017-01-24 10:11:38 -0500 | [diff] [blame] | 2316 | alg.hash_num_bytes + alg.signature_num_bytes, 64) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2317 | h.algorithm_type = alg.algorithm_type |
| 2318 | h.hash_offset = 0 |
| 2319 | h.hash_size = alg.hash_num_bytes |
| 2320 | # Signature offset and size - it's stored right after the hash |
| 2321 | # (in Authentication data block). |
| 2322 | h.signature_offset = alg.hash_num_bytes |
| 2323 | h.signature_size = alg.signature_num_bytes |
| 2324 | |
| 2325 | h.rollback_index = rollback_index |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2326 | h.flags = flags |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2327 | |
| 2328 | # Generate Header data block. |
| 2329 | header_data_blob = h.encode() |
| 2330 | |
| 2331 | # Generate Auxiliary data block. |
| 2332 | aux_data_blob = bytearray() |
| 2333 | aux_data_blob.extend(encoded_descriptors) |
| 2334 | aux_data_blob.extend(encoded_key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2335 | aux_data_blob.extend(pkmd_blob) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2336 | padding_bytes = h.auxiliary_data_block_size - len(aux_data_blob) |
| 2337 | aux_data_blob.extend('\0' * padding_bytes) |
| 2338 | |
| 2339 | # Calculate the hash. |
| 2340 | binary_hash = bytearray() |
| 2341 | binary_signature = bytearray() |
| 2342 | if algorithm_name != 'NONE': |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 2343 | ha = hashlib.new(alg.hash_name) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2344 | ha.update(header_data_blob) |
| 2345 | ha.update(aux_data_blob) |
| 2346 | binary_hash.extend(ha.digest()) |
| 2347 | |
| 2348 | # Calculate the signature. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2349 | padding_and_hash = str(bytearray(alg.padding)) + binary_hash |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 2350 | binary_signature.extend(raw_sign(signing_helper, algorithm_name, |
| 2351 | alg.signature_num_bytes, key_path, |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2352 | padding_and_hash)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2353 | |
| 2354 | # Generate Authentication data block. |
| 2355 | auth_data_blob = bytearray() |
| 2356 | auth_data_blob.extend(binary_hash) |
| 2357 | auth_data_blob.extend(binary_signature) |
| 2358 | padding_bytes = h.authentication_data_block_size - len(auth_data_blob) |
| 2359 | auth_data_blob.extend('\0' * padding_bytes) |
| 2360 | |
| 2361 | return header_data_blob + auth_data_blob + aux_data_blob |
| 2362 | |
| 2363 | def extract_public_key(self, key_path, output): |
| 2364 | """Implements the 'extract_public_key' command. |
| 2365 | |
| 2366 | Arguments: |
| 2367 | key_path: The path to a RSA private key file. |
| 2368 | output: The file to write to. |
| 2369 | """ |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2370 | output.write(encode_rsa_key(key_path)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2371 | |
David Zeuthen | b1b994d | 2017-03-06 18:01:31 -0500 | [diff] [blame] | 2372 | def append_vbmeta_image(self, image_filename, vbmeta_image_filename, |
| 2373 | partition_size): |
| 2374 | """Implementation of the append_vbmeta_image command. |
| 2375 | |
| 2376 | Arguments: |
| 2377 | image_filename: File to add the footer to. |
| 2378 | vbmeta_image_filename: File to get vbmeta struct from. |
| 2379 | partition_size: Size of partition. |
| 2380 | |
| 2381 | Raises: |
| 2382 | AvbError: If an argument is incorrect. |
| 2383 | """ |
| 2384 | image = ImageHandler(image_filename) |
| 2385 | |
| 2386 | if partition_size % image.block_size != 0: |
| 2387 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 2388 | 'block size {}.'.format(partition_size, |
| 2389 | image.block_size)) |
| 2390 | |
| 2391 | # If there's already a footer, truncate the image to its original |
| 2392 | # size. This way 'avbtool append_vbmeta_image' is idempotent. |
| 2393 | image.seek(image.image_size - AvbFooter.SIZE) |
| 2394 | try: |
| 2395 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2396 | # Existing footer found. Just truncate. |
| 2397 | original_image_size = footer.original_image_size |
| 2398 | image.truncate(footer.original_image_size) |
| 2399 | except (LookupError, struct.error): |
| 2400 | original_image_size = image.image_size |
| 2401 | |
| 2402 | # If anything goes wrong from here-on, restore the image back to |
| 2403 | # its original size. |
| 2404 | try: |
| 2405 | vbmeta_image_handler = ImageHandler(vbmeta_image_filename) |
| 2406 | vbmeta_blob = self._load_vbmeta_blob(vbmeta_image_handler) |
| 2407 | |
| 2408 | # If the image isn't sparse, its size might not be a multiple of |
| 2409 | # the block size. This will screw up padding later so just grow it. |
| 2410 | if image.image_size % image.block_size != 0: |
| 2411 | assert not image.is_sparse |
| 2412 | padding_needed = image.block_size - (image.image_size%image.block_size) |
| 2413 | image.truncate(image.image_size + padding_needed) |
| 2414 | |
| 2415 | # The append_raw() method requires content with size being a |
| 2416 | # multiple of |block_size| so add padding as needed. Also record |
| 2417 | # where this is written to since we'll need to put that in the |
| 2418 | # footer. |
| 2419 | vbmeta_offset = image.image_size |
| 2420 | padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) - |
| 2421 | len(vbmeta_blob)) |
| 2422 | vbmeta_blob_with_padding = vbmeta_blob + '\0'*padding_needed |
| 2423 | |
| 2424 | # Append vbmeta blob and footer |
| 2425 | image.append_raw(vbmeta_blob_with_padding) |
| 2426 | vbmeta_end_offset = vbmeta_offset + len(vbmeta_blob_with_padding) |
| 2427 | |
| 2428 | # Now insert a DONT_CARE chunk with enough bytes such that the |
| 2429 | # final Footer block is at the end of partition_size.. |
| 2430 | image.append_dont_care(partition_size - vbmeta_end_offset - |
| 2431 | 1*image.block_size) |
| 2432 | |
| 2433 | # Generate the Footer that tells where the VBMeta footer |
| 2434 | # is. Also put enough padding in the front of the footer since |
| 2435 | # we'll write out an entire block. |
| 2436 | footer = AvbFooter() |
| 2437 | footer.original_image_size = original_image_size |
| 2438 | footer.vbmeta_offset = vbmeta_offset |
| 2439 | footer.vbmeta_size = len(vbmeta_blob) |
| 2440 | footer_blob = footer.encode() |
| 2441 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 2442 | footer_blob) |
| 2443 | image.append_raw(footer_blob_with_padding) |
| 2444 | |
| 2445 | except: |
| 2446 | # Truncate back to original size, then re-raise |
| 2447 | image.truncate(original_image_size) |
| 2448 | raise |
| 2449 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2450 | def add_hash_footer(self, image_filename, partition_size, partition_name, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2451 | hash_algorithm, salt, chain_partitions, algorithm_name, |
| 2452 | key_path, |
| 2453 | public_key_metadata_path, rollback_index, flags, props, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2454 | props_from_file, kernel_cmdlines, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2455 | setup_rootfs_from_kernel, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2456 | include_descriptors_from_image, signing_helper, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2457 | release_string, append_to_release_string, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2458 | output_vbmeta_image, do_not_append_vbmeta_image): |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2459 | """Implementation of the add_hash_footer on unsparse images. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2460 | |
| 2461 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2462 | image_filename: File to add the footer to. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2463 | partition_size: Size of partition. |
| 2464 | partition_name: Name of partition (without A/B suffix). |
| 2465 | hash_algorithm: Hash algorithm to use. |
| 2466 | salt: Salt to use as a hexadecimal string or None to use /dev/urandom. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2467 | chain_partitions: List of partitions to chain. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2468 | algorithm_name: Name of algorithm to use. |
| 2469 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2470 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2471 | rollback_index: Rollback index. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2472 | flags: Flags value to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2473 | props: Properties to insert (List of strings of the form 'key:value'). |
| 2474 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 2475 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2476 | setup_rootfs_from_kernel: None or file to generate |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2477 | dm-verity kernel cmdline from. |
| 2478 | include_descriptors_from_image: List of file objects for which |
| 2479 | to insert descriptors from. |
Dzmitry Yatsushkevich | 4e55279 | 2016-12-15 10:27:48 -0800 | [diff] [blame] | 2480 | signing_helper: Program which signs a hash and return signature. |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2481 | release_string: None or avbtool release string. |
| 2482 | append_to_release_string: None or string to append. |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2483 | output_vbmeta_image: If not None, also write vbmeta struct to this file. |
| 2484 | do_not_append_vbmeta_image: If True, don't append vbmeta struct. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2485 | |
| 2486 | Raises: |
| 2487 | AvbError: If an argument is incorrect. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2488 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2489 | image = ImageHandler(image_filename) |
| 2490 | |
| 2491 | if partition_size % image.block_size != 0: |
| 2492 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 2493 | 'block size {}.'.format(partition_size, |
| 2494 | image.block_size)) |
| 2495 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2496 | # If there's already a footer, truncate the image to its original |
| 2497 | # size. This way 'avbtool add_hash_footer' is idempotent (modulo |
| 2498 | # salts). |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2499 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2500 | try: |
| 2501 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2502 | # Existing footer found. Just truncate. |
| 2503 | original_image_size = footer.original_image_size |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2504 | image.truncate(footer.original_image_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2505 | except (LookupError, struct.error): |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2506 | original_image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2507 | |
| 2508 | # If anything goes wrong from here-on, restore the image back to |
| 2509 | # its original size. |
| 2510 | try: |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2511 | # First, calculate the maximum image size such that an image |
| 2512 | # this size + metadata (footer + vbmeta struct) fits in |
| 2513 | # |partition_size|. |
| 2514 | max_metadata_size = self.MAX_VBMETA_SIZE + self.MAX_FOOTER_SIZE |
| 2515 | max_image_size = partition_size - max_metadata_size |
| 2516 | |
| 2517 | # If image size exceeds the maximum image size, fail. |
| 2518 | if image.image_size > max_image_size: |
| 2519 | raise AvbError('Image size of {} exceeds maximum image ' |
| 2520 | 'size of {} in order to fit in a partition ' |
| 2521 | 'size of {}.'.format(image.image_size, max_image_size, |
| 2522 | partition_size)) |
| 2523 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2524 | digest_size = len(hashlib.new(name=hash_algorithm).digest()) |
| 2525 | if salt: |
| 2526 | salt = salt.decode('hex') |
| 2527 | else: |
| 2528 | if salt is None: |
| 2529 | # If salt is not explicitly specified, choose a hash |
| 2530 | # that's the same size as the hash size. |
| 2531 | hash_size = digest_size |
| 2532 | salt = open('/dev/urandom').read(hash_size) |
| 2533 | else: |
| 2534 | salt = '' |
| 2535 | |
| 2536 | hasher = hashlib.new(name=hash_algorithm, string=salt) |
| 2537 | # TODO(zeuthen): might want to read this in chunks to avoid |
| 2538 | # memory pressure, then again, this is only supposed to be used |
| 2539 | # on kernel/initramfs partitions. Possible optimization. |
| 2540 | image.seek(0) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2541 | hasher.update(image.read(image.image_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2542 | digest = hasher.digest() |
| 2543 | |
| 2544 | h_desc = AvbHashDescriptor() |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2545 | h_desc.image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2546 | h_desc.hash_algorithm = hash_algorithm |
| 2547 | h_desc.partition_name = partition_name |
| 2548 | h_desc.salt = salt |
| 2549 | h_desc.digest = digest |
| 2550 | |
| 2551 | # Generate the VBMeta footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2552 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2553 | algorithm_name, key_path, public_key_metadata_path, [h_desc], |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2554 | chain_partitions, rollback_index, flags, props, props_from_file, |
| 2555 | kernel_cmdlines, setup_rootfs_from_kernel, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2556 | include_descriptors_from_image, signing_helper, release_string, |
| 2557 | append_to_release_string) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2558 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2559 | # If the image isn't sparse, its size might not be a multiple of |
| 2560 | # the block size. This will screw up padding later so just grow it. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2561 | if image.image_size % image.block_size != 0: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2562 | assert not image.is_sparse |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2563 | padding_needed = image.block_size - (image.image_size%image.block_size) |
| 2564 | image.truncate(image.image_size + padding_needed) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2565 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2566 | # The append_raw() method requires content with size being a |
| 2567 | # multiple of |block_size| so add padding as needed. Also record |
| 2568 | # where this is written to since we'll need to put that in the |
| 2569 | # footer. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2570 | vbmeta_offset = image.image_size |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2571 | padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) - |
| 2572 | len(vbmeta_blob)) |
| 2573 | vbmeta_blob_with_padding = vbmeta_blob + '\0'*padding_needed |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2574 | |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2575 | # Write vbmeta blob, if requested. |
| 2576 | if output_vbmeta_image: |
| 2577 | output_vbmeta_image.write(vbmeta_blob) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2578 | |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2579 | # Append vbmeta blob and footer, unless requested not to. |
| 2580 | if not do_not_append_vbmeta_image: |
| 2581 | image.append_raw(vbmeta_blob_with_padding) |
| 2582 | vbmeta_end_offset = vbmeta_offset + len(vbmeta_blob_with_padding) |
| 2583 | |
| 2584 | # Now insert a DONT_CARE chunk with enough bytes such that the |
| 2585 | # final Footer block is at the end of partition_size.. |
| 2586 | image.append_dont_care(partition_size - vbmeta_end_offset - |
| 2587 | 1*image.block_size) |
| 2588 | |
| 2589 | # Generate the Footer that tells where the VBMeta footer |
| 2590 | # is. Also put enough padding in the front of the footer since |
| 2591 | # we'll write out an entire block. |
| 2592 | footer = AvbFooter() |
| 2593 | footer.original_image_size = original_image_size |
| 2594 | footer.vbmeta_offset = vbmeta_offset |
| 2595 | footer.vbmeta_size = len(vbmeta_blob) |
| 2596 | footer_blob = footer.encode() |
| 2597 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 2598 | footer_blob) |
| 2599 | image.append_raw(footer_blob_with_padding) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2600 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2601 | except: |
| 2602 | # Truncate back to original size, then re-raise |
| 2603 | image.truncate(original_image_size) |
| 2604 | raise |
| 2605 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2606 | def add_hashtree_footer(self, image_filename, partition_size, partition_name, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2607 | generate_fec, fec_num_roots, hash_algorithm, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2608 | block_size, salt, chain_partitions, algorithm_name, |
| 2609 | key_path, |
| 2610 | public_key_metadata_path, rollback_index, flags, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2611 | props, props_from_file, kernel_cmdlines, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2612 | setup_rootfs_from_kernel, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2613 | include_descriptors_from_image, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2614 | calc_max_image_size, signing_helper, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2615 | release_string, append_to_release_string, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2616 | output_vbmeta_image, do_not_append_vbmeta_image): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2617 | """Implements the 'add_hashtree_footer' command. |
| 2618 | |
| 2619 | See https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for |
| 2620 | more information about dm-verity and these hashes. |
| 2621 | |
| 2622 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2623 | image_filename: File to add the footer to. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2624 | partition_size: Size of partition. |
| 2625 | partition_name: Name of partition (without A/B suffix). |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2626 | generate_fec: If True, generate FEC codes. |
| 2627 | fec_num_roots: Number of roots for FEC. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2628 | hash_algorithm: Hash algorithm to use. |
| 2629 | block_size: Block size to use. |
| 2630 | salt: Salt to use as a hexadecimal string or None to use /dev/urandom. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2631 | chain_partitions: List of partitions to chain. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2632 | algorithm_name: Name of algorithm to use. |
| 2633 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2634 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2635 | rollback_index: Rollback index. |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2636 | flags: Flags value to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2637 | props: Properties to insert (List of strings of the form 'key:value'). |
| 2638 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 2639 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 2640 | setup_rootfs_from_kernel: None or file to generate |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2641 | dm-verity kernel cmdline from. |
| 2642 | include_descriptors_from_image: List of file objects for which |
| 2643 | to insert descriptors from. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2644 | calc_max_image_size: Don't store the hashtree or footer - instead |
| 2645 | calculate the maximum image size leaving enough room for hashtree |
| 2646 | and metadata with the given |partition_size|. |
Dzmitry Yatsushkevich | 4e55279 | 2016-12-15 10:27:48 -0800 | [diff] [blame] | 2647 | signing_helper: Program which signs a hash and return signature. |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2648 | release_string: None or avbtool release string. |
| 2649 | append_to_release_string: None or string to append. |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2650 | output_vbmeta_image: If not None, also write vbmeta struct to this file. |
| 2651 | do_not_append_vbmeta_image: If True, don't append vbmeta struct. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2652 | |
| 2653 | Raises: |
| 2654 | AvbError: If an argument is incorrect. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2655 | """ |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2656 | digest_size = len(hashlib.new(name=hash_algorithm).digest()) |
| 2657 | digest_padding = round_to_pow2(digest_size) - digest_size |
| 2658 | |
| 2659 | # First, calculate the maximum image size such that an image |
| 2660 | # this size + the hashtree + metadata (footer + vbmeta struct) |
| 2661 | # fits in |partition_size|. We use very conservative figures for |
| 2662 | # metadata. |
| 2663 | (_, max_tree_size) = calc_hash_level_offsets( |
| 2664 | partition_size, block_size, digest_size + digest_padding) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2665 | max_fec_size = 0 |
| 2666 | if generate_fec: |
| 2667 | max_fec_size = calc_fec_data_size(partition_size, fec_num_roots) |
| 2668 | max_metadata_size = (max_fec_size + max_tree_size + |
| 2669 | self.MAX_VBMETA_SIZE + |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2670 | self.MAX_FOOTER_SIZE) |
| 2671 | max_image_size = partition_size - max_metadata_size |
| 2672 | |
| 2673 | # If we're asked to only calculate the maximum image size, we're done. |
| 2674 | if calc_max_image_size: |
| 2675 | print '{}'.format(max_image_size) |
| 2676 | return |
| 2677 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2678 | image = ImageHandler(image_filename) |
| 2679 | |
| 2680 | if partition_size % image.block_size != 0: |
| 2681 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 2682 | 'block size {}.'.format(partition_size, |
| 2683 | image.block_size)) |
| 2684 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2685 | # If there's already a footer, truncate the image to its original |
| 2686 | # size. This way 'avbtool add_hashtree_footer' is idempotent |
| 2687 | # (modulo salts). |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2688 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2689 | try: |
| 2690 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2691 | # Existing footer found. Just truncate. |
| 2692 | original_image_size = footer.original_image_size |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2693 | image.truncate(footer.original_image_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2694 | except (LookupError, struct.error): |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2695 | original_image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2696 | |
| 2697 | # If anything goes wrong from here-on, restore the image back to |
| 2698 | # its original size. |
| 2699 | try: |
| 2700 | # Ensure image is multiple of block_size. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2701 | rounded_image_size = round_to_multiple(image.image_size, block_size) |
| 2702 | if rounded_image_size > image.image_size: |
| 2703 | image.append_raw('\0' * (rounded_image_size - image.image_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2704 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2705 | # If image size exceeds the maximum image size, fail. |
| 2706 | if image.image_size > max_image_size: |
| 2707 | raise AvbError('Image size of {} exceeds maximum image ' |
| 2708 | 'size of {} in order to fit in a partition ' |
| 2709 | 'size of {}.'.format(image.image_size, max_image_size, |
| 2710 | partition_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2711 | |
| 2712 | if salt: |
| 2713 | salt = salt.decode('hex') |
| 2714 | else: |
| 2715 | if salt is None: |
| 2716 | # If salt is not explicitly specified, choose a hash |
| 2717 | # that's the same size as the hash size. |
| 2718 | hash_size = digest_size |
| 2719 | salt = open('/dev/urandom').read(hash_size) |
| 2720 | else: |
| 2721 | salt = '' |
| 2722 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2723 | # Hashes are stored upside down so we need to calculate hash |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2724 | # offsets in advance. |
| 2725 | (hash_level_offsets, tree_size) = calc_hash_level_offsets( |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2726 | image.image_size, block_size, digest_size + digest_padding) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2727 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2728 | # If the image isn't sparse, its size might not be a multiple of |
| 2729 | # the block size. This will screw up padding later so just grow it. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2730 | if image.image_size % image.block_size != 0: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2731 | assert not image.is_sparse |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2732 | padding_needed = image.block_size - (image.image_size%image.block_size) |
| 2733 | image.truncate(image.image_size + padding_needed) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2734 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2735 | # Generate the tree and add padding as needed. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2736 | tree_offset = image.image_size |
| 2737 | root_digest, hash_tree = generate_hash_tree(image, image.image_size, |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2738 | block_size, |
| 2739 | hash_algorithm, salt, |
| 2740 | digest_padding, |
| 2741 | hash_level_offsets, |
| 2742 | tree_size) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2743 | |
| 2744 | # Generate HashtreeDescriptor with details about the tree we |
| 2745 | # just generated. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2746 | ht_desc = AvbHashtreeDescriptor() |
| 2747 | ht_desc.dm_verity_version = 1 |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2748 | ht_desc.image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2749 | ht_desc.tree_offset = tree_offset |
| 2750 | ht_desc.tree_size = tree_size |
| 2751 | ht_desc.data_block_size = block_size |
| 2752 | ht_desc.hash_block_size = block_size |
| 2753 | ht_desc.hash_algorithm = hash_algorithm |
| 2754 | ht_desc.partition_name = partition_name |
| 2755 | ht_desc.salt = salt |
| 2756 | ht_desc.root_digest = root_digest |
| 2757 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2758 | # Write the hash tree |
| 2759 | padding_needed = (round_to_multiple(len(hash_tree), image.block_size) - |
| 2760 | len(hash_tree)) |
| 2761 | hash_tree_with_padding = hash_tree + '\0'*padding_needed |
| 2762 | image.append_raw(hash_tree_with_padding) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2763 | len_hashtree_and_fec = len(hash_tree_with_padding) |
| 2764 | |
| 2765 | # Generate FEC codes, if requested. |
| 2766 | if generate_fec: |
| 2767 | fec_data = generate_fec_data(image_filename, fec_num_roots) |
| 2768 | padding_needed = (round_to_multiple(len(fec_data), image.block_size) - |
| 2769 | len(fec_data)) |
| 2770 | fec_data_with_padding = fec_data + '\0'*padding_needed |
| 2771 | fec_offset = image.image_size |
| 2772 | image.append_raw(fec_data_with_padding) |
| 2773 | len_hashtree_and_fec += len(fec_data_with_padding) |
| 2774 | # Update the hashtree descriptor. |
| 2775 | ht_desc.fec_num_roots = fec_num_roots |
| 2776 | ht_desc.fec_offset = fec_offset |
| 2777 | ht_desc.fec_size = len(fec_data) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2778 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2779 | # Generate the VBMeta footer and add padding as needed. |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2780 | vbmeta_offset = tree_offset + len_hashtree_and_fec |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2781 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2782 | algorithm_name, key_path, public_key_metadata_path, [ht_desc], |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 2783 | chain_partitions, rollback_index, flags, props, props_from_file, |
| 2784 | kernel_cmdlines, setup_rootfs_from_kernel, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 2785 | include_descriptors_from_image, signing_helper, release_string, |
| 2786 | append_to_release_string) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2787 | padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) - |
| 2788 | len(vbmeta_blob)) |
| 2789 | vbmeta_blob_with_padding = vbmeta_blob + '\0'*padding_needed |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2790 | |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2791 | # Write vbmeta blob, if requested. |
| 2792 | if output_vbmeta_image: |
| 2793 | output_vbmeta_image.write(vbmeta_blob) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2794 | |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 2795 | # Append vbmeta blob and footer, unless requested not to. |
| 2796 | if not do_not_append_vbmeta_image: |
| 2797 | image.append_raw(vbmeta_blob_with_padding) |
| 2798 | |
| 2799 | # Now insert a DONT_CARE chunk with enough bytes such that the |
| 2800 | # final Footer block is at the end of partition_size.. |
| 2801 | image.append_dont_care(partition_size - image.image_size - |
| 2802 | 1*image.block_size) |
| 2803 | |
| 2804 | # Generate the Footer that tells where the VBMeta footer |
| 2805 | # is. Also put enough padding in the front of the footer since |
| 2806 | # we'll write out an entire block. |
| 2807 | footer = AvbFooter() |
| 2808 | footer.original_image_size = original_image_size |
| 2809 | footer.vbmeta_offset = vbmeta_offset |
| 2810 | footer.vbmeta_size = len(vbmeta_blob) |
| 2811 | footer_blob = footer.encode() |
| 2812 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 2813 | footer_blob) |
| 2814 | image.append_raw(footer_blob_with_padding) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2815 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2816 | except: |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2817 | # Truncate back to original size, then re-raise. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2818 | image.truncate(original_image_size) |
| 2819 | raise |
| 2820 | |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2821 | def make_atx_certificate(self, output, authority_key_path, subject_key_path, |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2822 | subject_key_version, subject, |
| 2823 | is_intermediate_authority, signing_helper): |
| 2824 | """Implements the 'make_atx_certificate' command. |
| 2825 | |
| 2826 | Android Things certificates are required for Android Things public key |
| 2827 | metadata. They chain the vbmeta signing key for a particular product back to |
| 2828 | a fused, permanent root key. These certificates are fixed-length and fixed- |
| 2829 | format with the explicit goal of not parsing ASN.1 in bootloader code. |
| 2830 | |
| 2831 | Arguments: |
| 2832 | output: Certificate will be written to this file on success. |
| 2833 | authority_key_path: A PEM file path with the authority private key. |
| 2834 | If None, then a certificate will be created without a |
| 2835 | signature. The signature can be created out-of-band |
| 2836 | and appended. |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2837 | subject_key_path: Path to a PEM or DER subject public key. |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2838 | subject_key_version: A 64-bit version value. If this is None, the number |
| 2839 | of seconds since the epoch is used. |
| 2840 | subject: A subject identifier. For Product Signing Key certificates this |
| 2841 | should be the same Product ID found in the permanent attributes. |
| 2842 | is_intermediate_authority: True if the certificate is for an intermediate |
| 2843 | authority. |
| 2844 | signing_helper: Program which signs a hash and returns the signature. |
| 2845 | """ |
| 2846 | signed_data = bytearray() |
| 2847 | signed_data.extend(struct.pack('<I', 1)) # Format Version |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2848 | signed_data.extend(encode_rsa_key(subject_key_path)) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2849 | hasher = hashlib.sha256() |
| 2850 | hasher.update(subject) |
| 2851 | signed_data.extend(hasher.digest()) |
| 2852 | usage = 'com.google.android.things.vboot' |
| 2853 | if is_intermediate_authority: |
| 2854 | usage += '.ca' |
| 2855 | hasher = hashlib.sha256() |
| 2856 | hasher.update(usage) |
| 2857 | signed_data.extend(hasher.digest()) |
| 2858 | if not subject_key_version: |
| 2859 | subject_key_version = int(time.time()) |
| 2860 | signed_data.extend(struct.pack('<Q', subject_key_version)) |
| 2861 | signature = bytearray() |
| 2862 | if authority_key_path: |
| 2863 | padding_and_hash = bytearray() |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2864 | algorithm_name = 'SHA512_RSA4096' |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 2865 | alg = ALGORITHMS[algorithm_name] |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2866 | hasher = hashlib.sha512() |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 2867 | padding_and_hash.extend(alg.padding) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2868 | hasher.update(signed_data) |
| 2869 | padding_and_hash.extend(hasher.digest()) |
| 2870 | signature.extend(raw_sign(signing_helper, algorithm_name, |
Esun Kim | ff44f23 | 2017-03-30 10:34:54 +0900 | [diff] [blame] | 2871 | alg.signature_num_bytes, authority_key_path, |
| 2872 | padding_and_hash)) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2873 | output.write(signed_data) |
| 2874 | output.write(signature) |
| 2875 | |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2876 | def make_atx_permanent_attributes(self, output, root_authority_key_path, |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2877 | product_id): |
| 2878 | """Implements the 'make_atx_permanent_attributes' command. |
| 2879 | |
| 2880 | Android Things permanent attributes are designed to be permanent for a |
| 2881 | particular product and a hash of these attributes should be fused into |
| 2882 | hardware to enforce this. |
| 2883 | |
| 2884 | Arguments: |
| 2885 | output: Attributes will be written to this file on success. |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2886 | root_authority_key_path: Path to a PEM or DER public key for |
| 2887 | the root authority. |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2888 | product_id: A 16-byte Product ID. |
| 2889 | |
| 2890 | Raises: |
| 2891 | AvbError: If an argument is incorrect. |
| 2892 | """ |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2893 | EXPECTED_PRODUCT_ID_SIZE = 16 |
| 2894 | if len(product_id) != EXPECTED_PRODUCT_ID_SIZE: |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2895 | raise AvbError('Invalid Product ID length.') |
| 2896 | output.write(struct.pack('<I', 1)) # Format Version |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 2897 | output.write(encode_rsa_key(root_authority_key_path)) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2898 | output.write(product_id) |
| 2899 | |
| 2900 | def make_atx_metadata(self, output, intermediate_key_certificate, |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2901 | product_key_certificate): |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2902 | """Implements the 'make_atx_metadata' command. |
| 2903 | |
| 2904 | Android Things metadata are included in vbmeta images to facilitate |
| 2905 | verification. The output of this command can be used as the |
| 2906 | public_key_metadata argument to other commands. |
| 2907 | |
| 2908 | Arguments: |
| 2909 | output: Metadata will be written to this file on success. |
| 2910 | intermediate_key_certificate: A certificate file as output by |
| 2911 | make_atx_certificate with |
| 2912 | is_intermediate_authority set to true. |
| 2913 | product_key_certificate: A certificate file as output by |
| 2914 | make_atx_certificate with |
| 2915 | is_intermediate_authority set to false. |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2916 | |
| 2917 | Raises: |
| 2918 | AvbError: If an argument is incorrect. |
| 2919 | """ |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2920 | EXPECTED_CERTIFICATE_SIZE = 1620 |
| 2921 | if len(intermediate_key_certificate) != EXPECTED_CERTIFICATE_SIZE: |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2922 | raise AvbError('Invalid intermediate key certificate length.') |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 2923 | if len(product_key_certificate) != EXPECTED_CERTIFICATE_SIZE: |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2924 | raise AvbError('Invalid product key certificate length.') |
| 2925 | output.write(struct.pack('<I', 1)) # Format Version |
| 2926 | output.write(intermediate_key_certificate) |
| 2927 | output.write(product_key_certificate) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 2928 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2929 | |
| 2930 | def calc_hash_level_offsets(image_size, block_size, digest_size): |
| 2931 | """Calculate the offsets of all the hash-levels in a Merkle-tree. |
| 2932 | |
| 2933 | Arguments: |
| 2934 | image_size: The size of the image to calculate a Merkle-tree for. |
| 2935 | block_size: The block size, e.g. 4096. |
| 2936 | digest_size: The size of each hash, e.g. 32 for SHA-256. |
| 2937 | |
| 2938 | Returns: |
| 2939 | A tuple where the first argument is an array of offsets and the |
| 2940 | second is size of the tree, in bytes. |
| 2941 | """ |
| 2942 | level_offsets = [] |
| 2943 | level_sizes = [] |
| 2944 | tree_size = 0 |
| 2945 | |
| 2946 | num_levels = 0 |
| 2947 | size = image_size |
| 2948 | while size > block_size: |
| 2949 | num_blocks = (size + block_size - 1) / block_size |
| 2950 | level_size = round_to_multiple(num_blocks * digest_size, block_size) |
| 2951 | |
| 2952 | level_sizes.append(level_size) |
| 2953 | tree_size += level_size |
| 2954 | num_levels += 1 |
| 2955 | |
| 2956 | size = level_size |
| 2957 | |
| 2958 | for n in range(0, num_levels): |
| 2959 | offset = 0 |
| 2960 | for m in range(n + 1, num_levels): |
| 2961 | offset += level_sizes[m] |
| 2962 | level_offsets.append(offset) |
| 2963 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2964 | return level_offsets, tree_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2965 | |
| 2966 | |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2967 | # See system/extras/libfec/include/fec/io.h for these definitions. |
| 2968 | FEC_FOOTER_FORMAT = '<LLLLLQ32s' |
| 2969 | FEC_MAGIC = 0xfecfecfe |
| 2970 | |
| 2971 | |
| 2972 | def calc_fec_data_size(image_size, num_roots): |
| 2973 | """Calculates how much space FEC data will take. |
| 2974 | |
| 2975 | Args: |
| 2976 | image_size: The size of the image. |
| 2977 | num_roots: Number of roots. |
| 2978 | |
| 2979 | Returns: |
| 2980 | The number of bytes needed for FEC for an image of the given size |
| 2981 | and with the requested number of FEC roots. |
| 2982 | |
| 2983 | Raises: |
| 2984 | ValueError: If output from the 'fec' tool is invalid. |
| 2985 | |
| 2986 | """ |
| 2987 | p = subprocess.Popen( |
| 2988 | ['fec', '--print-fec-size', str(image_size), '--roots', str(num_roots)], |
| 2989 | stdout=subprocess.PIPE, |
| 2990 | stderr=subprocess.PIPE) |
| 2991 | (pout, perr) = p.communicate() |
| 2992 | retcode = p.wait() |
| 2993 | if retcode != 0: |
| 2994 | raise ValueError('Error invoking fec: {}'.format(perr)) |
| 2995 | return int(pout) |
| 2996 | |
| 2997 | |
| 2998 | def generate_fec_data(image_filename, num_roots): |
| 2999 | """Generate FEC codes for an image. |
| 3000 | |
| 3001 | Args: |
| 3002 | image_filename: The filename of the image. |
| 3003 | num_roots: Number of roots. |
| 3004 | |
| 3005 | Returns: |
| 3006 | The FEC data blob. |
| 3007 | |
| 3008 | Raises: |
| 3009 | ValueError: If output from the 'fec' tool is invalid. |
| 3010 | """ |
| 3011 | fec_tmpfile = tempfile.NamedTemporaryFile() |
| 3012 | subprocess.check_call( |
| 3013 | ['fec', '--encode', '--roots', str(num_roots), image_filename, |
| 3014 | fec_tmpfile.name], |
| 3015 | stderr=open(os.devnull)) |
| 3016 | fec_data = fec_tmpfile.read() |
| 3017 | footer_size = struct.calcsize(FEC_FOOTER_FORMAT) |
| 3018 | footer_data = fec_data[-footer_size:] |
| 3019 | (magic, _, _, num_roots, fec_size, _, _) = struct.unpack(FEC_FOOTER_FORMAT, |
| 3020 | footer_data) |
| 3021 | if magic != FEC_MAGIC: |
| 3022 | raise ValueError('Unexpected magic in FEC footer') |
| 3023 | return fec_data[0:fec_size] |
| 3024 | |
| 3025 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3026 | def generate_hash_tree(image, image_size, block_size, hash_alg_name, salt, |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3027 | digest_padding, hash_level_offsets, tree_size): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3028 | """Generates a Merkle-tree for a file. |
| 3029 | |
| 3030 | Args: |
| 3031 | image: The image, as a file. |
| 3032 | image_size: The size of the image. |
| 3033 | block_size: The block size, e.g. 4096. |
| 3034 | hash_alg_name: The hash algorithm, e.g. 'sha256' or 'sha1'. |
| 3035 | salt: The salt to use. |
| 3036 | digest_padding: The padding for each digest. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3037 | hash_level_offsets: The offsets from calc_hash_level_offsets(). |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3038 | tree_size: The size of the tree, in number of bytes. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3039 | |
| 3040 | Returns: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3041 | A tuple where the first element is the top-level hash and the |
| 3042 | second element is the hash-tree. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3043 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3044 | hash_ret = bytearray(tree_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3045 | hash_src_offset = 0 |
| 3046 | hash_src_size = image_size |
| 3047 | level_num = 0 |
| 3048 | while hash_src_size > block_size: |
| 3049 | level_output = '' |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3050 | remaining = hash_src_size |
| 3051 | while remaining > 0: |
| 3052 | hasher = hashlib.new(name=hash_alg_name, string=salt) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3053 | # Only read from the file for the first level - for subsequent |
| 3054 | # levels, access the array we're building. |
| 3055 | if level_num == 0: |
| 3056 | image.seek(hash_src_offset + hash_src_size - remaining) |
| 3057 | data = image.read(min(remaining, block_size)) |
| 3058 | else: |
| 3059 | offset = hash_level_offsets[level_num - 1] + hash_src_size - remaining |
| 3060 | data = hash_ret[offset:offset + block_size] |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3061 | hasher.update(data) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3062 | |
| 3063 | remaining -= len(data) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3064 | if len(data) < block_size: |
| 3065 | hasher.update('\0' * (block_size - len(data))) |
| 3066 | level_output += hasher.digest() |
| 3067 | if digest_padding > 0: |
| 3068 | level_output += '\0' * digest_padding |
| 3069 | |
| 3070 | padding_needed = (round_to_multiple( |
| 3071 | len(level_output), block_size) - len(level_output)) |
| 3072 | level_output += '\0' * padding_needed |
| 3073 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3074 | # Copy level-output into resulting tree. |
| 3075 | offset = hash_level_offsets[level_num] |
| 3076 | hash_ret[offset:offset + len(level_output)] = level_output |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3077 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3078 | # Continue on to the next level. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3079 | hash_src_size = len(level_output) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3080 | level_num += 1 |
| 3081 | |
| 3082 | hasher = hashlib.new(name=hash_alg_name, string=salt) |
| 3083 | hasher.update(level_output) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3084 | return hasher.digest(), hash_ret |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3085 | |
| 3086 | |
| 3087 | class AvbTool(object): |
| 3088 | """Object for avbtool command-line tool.""" |
| 3089 | |
| 3090 | def __init__(self): |
| 3091 | """Initializer method.""" |
| 3092 | self.avb = Avb() |
| 3093 | |
| 3094 | def _add_common_args(self, sub_parser): |
| 3095 | """Adds arguments used by several sub-commands. |
| 3096 | |
| 3097 | Arguments: |
| 3098 | sub_parser: The parser to add arguments to. |
| 3099 | """ |
| 3100 | sub_parser.add_argument('--algorithm', |
| 3101 | help='Algorithm to use (default: NONE)', |
| 3102 | metavar='ALGORITHM', |
| 3103 | default='NONE') |
| 3104 | sub_parser.add_argument('--key', |
| 3105 | help='Path to RSA private key file', |
| 3106 | metavar='KEY', |
| 3107 | required=False) |
Dzmitry Yatsushkevich | 4e55279 | 2016-12-15 10:27:48 -0800 | [diff] [blame] | 3108 | sub_parser.add_argument('--signing_helper', |
| 3109 | help='Path to helper used for signing', |
| 3110 | metavar='APP', |
| 3111 | default=None, |
| 3112 | required=False) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 3113 | sub_parser.add_argument('--public_key_metadata', |
| 3114 | help='Path to public key metadata file', |
| 3115 | metavar='KEY_METADATA', |
| 3116 | required=False) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3117 | sub_parser.add_argument('--rollback_index', |
| 3118 | help='Rollback Index', |
| 3119 | type=parse_number, |
| 3120 | default=0) |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 3121 | # This is used internally for unit tests. Do not include in --help output. |
| 3122 | sub_parser.add_argument('--internal_release_string', |
| 3123 | help=argparse.SUPPRESS) |
| 3124 | sub_parser.add_argument('--append_to_release_string', |
| 3125 | help='Text to append to release string', |
| 3126 | metavar='STR') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3127 | sub_parser.add_argument('--prop', |
| 3128 | help='Add property', |
| 3129 | metavar='KEY:VALUE', |
| 3130 | action='append') |
| 3131 | sub_parser.add_argument('--prop_from_file', |
| 3132 | help='Add property from file', |
| 3133 | metavar='KEY:PATH', |
| 3134 | action='append') |
| 3135 | sub_parser.add_argument('--kernel_cmdline', |
| 3136 | help='Add kernel cmdline', |
| 3137 | metavar='CMDLINE', |
| 3138 | action='append') |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 3139 | # TODO(zeuthen): the --setup_rootfs_from_kernel option used to be called |
| 3140 | # --generate_dm_verity_cmdline_from_hashtree. Remove support for the latter |
| 3141 | # at some future point. |
| 3142 | sub_parser.add_argument('--setup_rootfs_from_kernel', |
| 3143 | '--generate_dm_verity_cmdline_from_hashtree', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3144 | metavar='IMAGE', |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 3145 | help='Adds kernel cmdline to set up IMAGE', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3146 | type=argparse.FileType('rb')) |
| 3147 | sub_parser.add_argument('--include_descriptors_from_image', |
| 3148 | help='Include descriptors from image', |
| 3149 | metavar='IMAGE', |
| 3150 | action='append', |
| 3151 | type=argparse.FileType('rb')) |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3152 | # These are only allowed from top-level vbmeta and boot-in-lieu-of-vbmeta. |
| 3153 | sub_parser.add_argument('--chain_partition', |
| 3154 | help='Allow signed integrity-data for partition', |
| 3155 | metavar='PART_NAME:ROLLBACK_SLOT:KEY_PATH', |
| 3156 | action='append') |
| 3157 | sub_parser.add_argument('--flags', |
| 3158 | help='VBMeta flags', |
| 3159 | type=parse_number, |
| 3160 | default=0) |
| 3161 | sub_parser.add_argument('--set_hashtree_disabled_flag', |
| 3162 | help='Set the HASHTREE_DISABLED flag', |
| 3163 | action='store_true') |
| 3164 | |
| 3165 | def _fixup_common_args(self, args): |
| 3166 | """Common fixups needed by subcommands. |
| 3167 | |
| 3168 | Arguments: |
| 3169 | args: Arguments to modify. |
| 3170 | |
| 3171 | Returns: |
| 3172 | The modified arguments. |
| 3173 | """ |
| 3174 | if args.set_hashtree_disabled_flag: |
| 3175 | args.flags |= AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED |
| 3176 | return args |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3177 | |
| 3178 | def run(self, argv): |
| 3179 | """Command-line processor. |
| 3180 | |
| 3181 | Arguments: |
| 3182 | argv: Pass sys.argv from main. |
| 3183 | """ |
| 3184 | parser = argparse.ArgumentParser() |
| 3185 | subparsers = parser.add_subparsers(title='subcommands') |
| 3186 | |
| 3187 | sub_parser = subparsers.add_parser('version', |
| 3188 | help='Prints version of avbtool.') |
| 3189 | sub_parser.set_defaults(func=self.version) |
| 3190 | |
| 3191 | sub_parser = subparsers.add_parser('extract_public_key', |
| 3192 | help='Extract public key.') |
| 3193 | sub_parser.add_argument('--key', |
| 3194 | help='Path to RSA private key file', |
| 3195 | required=True) |
| 3196 | sub_parser.add_argument('--output', |
| 3197 | help='Output file name', |
| 3198 | type=argparse.FileType('wb'), |
| 3199 | required=True) |
| 3200 | sub_parser.set_defaults(func=self.extract_public_key) |
| 3201 | |
| 3202 | sub_parser = subparsers.add_parser('make_vbmeta_image', |
| 3203 | help='Makes a vbmeta image.') |
| 3204 | sub_parser.add_argument('--output', |
| 3205 | help='Output file name', |
| 3206 | type=argparse.FileType('wb'), |
| 3207 | required=True) |
| 3208 | self._add_common_args(sub_parser) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3209 | sub_parser.set_defaults(func=self.make_vbmeta_image) |
| 3210 | |
| 3211 | sub_parser = subparsers.add_parser('add_hash_footer', |
| 3212 | help='Add hashes and footer to image.') |
| 3213 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3214 | help='Image to add hashes to', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3215 | type=argparse.FileType('rab+')) |
| 3216 | sub_parser.add_argument('--partition_size', |
| 3217 | help='Partition size', |
| 3218 | type=parse_number, |
| 3219 | required=True) |
| 3220 | sub_parser.add_argument('--partition_name', |
| 3221 | help='Partition name', |
| 3222 | required=True) |
| 3223 | sub_parser.add_argument('--hash_algorithm', |
| 3224 | help='Hash algorithm to use (default: sha256)', |
| 3225 | default='sha256') |
| 3226 | sub_parser.add_argument('--salt', |
| 3227 | help='Salt in hex (default: /dev/urandom)') |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3228 | sub_parser.add_argument('--output_vbmeta_image', |
| 3229 | help='Also write vbmeta struct to file', |
| 3230 | type=argparse.FileType('wb')) |
| 3231 | sub_parser.add_argument('--do_not_append_vbmeta_image', |
| 3232 | help=('Do not append vbmeta struct or footer ' |
| 3233 | 'to the image'), |
| 3234 | action='store_true') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3235 | self._add_common_args(sub_parser) |
| 3236 | sub_parser.set_defaults(func=self.add_hash_footer) |
| 3237 | |
David Zeuthen | b1b994d | 2017-03-06 18:01:31 -0500 | [diff] [blame] | 3238 | sub_parser = subparsers.add_parser('append_vbmeta_image', |
| 3239 | help='Append vbmeta image to image.') |
| 3240 | sub_parser.add_argument('--image', |
| 3241 | help='Image to append vbmeta blob to', |
| 3242 | type=argparse.FileType('rab+')) |
| 3243 | sub_parser.add_argument('--partition_size', |
| 3244 | help='Partition size', |
| 3245 | type=parse_number, |
| 3246 | required=True) |
| 3247 | sub_parser.add_argument('--vbmeta_image', |
| 3248 | help='Image with vbmeta blob to append', |
| 3249 | type=argparse.FileType('rb')) |
| 3250 | sub_parser.set_defaults(func=self.append_vbmeta_image) |
| 3251 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3252 | sub_parser = subparsers.add_parser('add_hashtree_footer', |
| 3253 | help='Add hashtree and footer to image.') |
| 3254 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3255 | help='Image to add hashtree to', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3256 | type=argparse.FileType('rab+')) |
| 3257 | sub_parser.add_argument('--partition_size', |
| 3258 | help='Partition size', |
| 3259 | type=parse_number, |
| 3260 | required=True) |
| 3261 | sub_parser.add_argument('--partition_name', |
| 3262 | help='Partition name', |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3263 | default=None) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3264 | sub_parser.add_argument('--hash_algorithm', |
| 3265 | help='Hash algorithm to use (default: sha1)', |
| 3266 | default='sha1') |
| 3267 | sub_parser.add_argument('--salt', |
| 3268 | help='Salt in hex (default: /dev/urandom)') |
| 3269 | sub_parser.add_argument('--block_size', |
| 3270 | help='Block size (default: 4096)', |
| 3271 | type=parse_number, |
| 3272 | default=4096) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 3273 | sub_parser.add_argument('--generate_fec', |
| 3274 | help='Add forward-error-correction codes', |
| 3275 | action='store_true') |
| 3276 | sub_parser.add_argument('--fec_num_roots', |
| 3277 | help='Number of roots for FEC (default: 2)', |
| 3278 | type=parse_number, |
| 3279 | default=2) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3280 | sub_parser.add_argument('--calc_max_image_size', |
| 3281 | help=('Don\'t store the hashtree or footer - ' |
| 3282 | 'instead calculate the maximum image size ' |
| 3283 | 'leaving enough room for hashtree ' |
| 3284 | 'and metadata with the given partition ' |
| 3285 | 'size.'), |
| 3286 | action='store_true') |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3287 | sub_parser.add_argument('--output_vbmeta_image', |
| 3288 | help='Also write vbmeta struct to file', |
| 3289 | type=argparse.FileType('wb')) |
| 3290 | sub_parser.add_argument('--do_not_append_vbmeta_image', |
| 3291 | help=('Do not append vbmeta struct or footer ' |
| 3292 | 'to the image'), |
| 3293 | action='store_true') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3294 | self._add_common_args(sub_parser) |
| 3295 | sub_parser.set_defaults(func=self.add_hashtree_footer) |
| 3296 | |
| 3297 | sub_parser = subparsers.add_parser('erase_footer', |
| 3298 | help='Erase footer from an image.') |
| 3299 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3300 | help='Image with a footer', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3301 | type=argparse.FileType('rwb+'), |
| 3302 | required=True) |
| 3303 | sub_parser.add_argument('--keep_hashtree', |
David Zeuthen | fbb61fa | 2017-02-02 12:11:49 -0500 | [diff] [blame] | 3304 | help='Keep the hashtree and FEC in the image', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3305 | action='store_true') |
| 3306 | sub_parser.set_defaults(func=self.erase_footer) |
| 3307 | |
David Zeuthen | 2bc232b | 2017-04-19 14:25:19 -0400 | [diff] [blame] | 3308 | sub_parser = subparsers.add_parser('resize_image', |
| 3309 | help='Resize image with a footer.') |
| 3310 | sub_parser.add_argument('--image', |
| 3311 | help='Image with a footer', |
| 3312 | type=argparse.FileType('rwb+'), |
| 3313 | required=True) |
| 3314 | sub_parser.add_argument('--partition_size', |
| 3315 | help='New partition size', |
| 3316 | type=parse_number) |
| 3317 | sub_parser.set_defaults(func=self.resize_image) |
| 3318 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3319 | sub_parser = subparsers.add_parser( |
| 3320 | 'info_image', |
| 3321 | help='Show information about vbmeta or footer.') |
| 3322 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3323 | help='Image to show information about', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3324 | type=argparse.FileType('rb'), |
| 3325 | required=True) |
| 3326 | sub_parser.add_argument('--output', |
| 3327 | help='Write info to file', |
| 3328 | type=argparse.FileType('wt'), |
| 3329 | default=sys.stdout) |
| 3330 | sub_parser.set_defaults(func=self.info_image) |
| 3331 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 3332 | sub_parser = subparsers.add_parser( |
| 3333 | 'verify_image', |
| 3334 | help='Verify an image.') |
| 3335 | sub_parser.add_argument('--image', |
| 3336 | help='Image to verify', |
| 3337 | type=argparse.FileType('rb'), |
| 3338 | required=True) |
| 3339 | sub_parser.set_defaults(func=self.verify_image) |
| 3340 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3341 | sub_parser = subparsers.add_parser('set_ab_metadata', |
| 3342 | help='Set A/B metadata.') |
| 3343 | sub_parser.add_argument('--misc_image', |
| 3344 | help=('The misc image to modify. If the image does ' |
| 3345 | 'not exist, it will be created.'), |
| 3346 | type=argparse.FileType('r+b'), |
| 3347 | required=True) |
| 3348 | sub_parser.add_argument('--slot_data', |
| 3349 | help=('Slot data of the form "priority", ' |
| 3350 | '"tries_remaining", "sucessful_boot" for ' |
| 3351 | 'slot A followed by the same for slot B, ' |
| 3352 | 'separated by colons. The default value ' |
| 3353 | 'is 15:7:0:14:7:0.'), |
| 3354 | default='15:7:0:14:7:0') |
| 3355 | sub_parser.set_defaults(func=self.set_ab_metadata) |
| 3356 | |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3357 | sub_parser = subparsers.add_parser( |
| 3358 | 'make_atx_certificate', |
| 3359 | help='Create an Android Things eXtension (ATX) certificate.') |
| 3360 | sub_parser.add_argument('--output', |
| 3361 | help='Write certificate to file', |
| 3362 | type=argparse.FileType('wb'), |
| 3363 | default=sys.stdout) |
| 3364 | sub_parser.add_argument('--subject', |
| 3365 | help=('Path to subject file'), |
| 3366 | type=argparse.FileType('rb'), |
| 3367 | required=True) |
| 3368 | sub_parser.add_argument('--subject_key', |
| 3369 | help=('Path to subject RSA public key file'), |
| 3370 | type=argparse.FileType('rb'), |
| 3371 | required=True) |
| 3372 | sub_parser.add_argument('--subject_key_version', |
| 3373 | help=('Version of the subject key'), |
| 3374 | type=parse_number, |
| 3375 | required=False) |
| 3376 | sub_parser.add_argument('--subject_is_intermediate_authority', |
| 3377 | help=('Generate an intermediate authority ' |
| 3378 | 'certificate'), |
| 3379 | action='store_true') |
| 3380 | sub_parser.add_argument('--authority_key', |
| 3381 | help='Path to authority RSA private key file', |
| 3382 | required=False) |
| 3383 | sub_parser.add_argument('--signing_helper', |
| 3384 | help='Path to helper used for signing', |
| 3385 | metavar='APP', |
| 3386 | default=None, |
| 3387 | required=False) |
| 3388 | sub_parser.set_defaults(func=self.make_atx_certificate) |
| 3389 | |
| 3390 | sub_parser = subparsers.add_parser( |
| 3391 | 'make_atx_permanent_attributes', |
| 3392 | help='Create Android Things eXtension (ATX) permanent attributes.') |
| 3393 | sub_parser.add_argument('--output', |
| 3394 | help='Write attributes to file', |
| 3395 | type=argparse.FileType('wb'), |
| 3396 | default=sys.stdout) |
| 3397 | sub_parser.add_argument('--root_authority_key', |
| 3398 | help='Path to authority RSA public key file', |
| 3399 | type=argparse.FileType('rb'), |
| 3400 | required=True) |
| 3401 | sub_parser.add_argument('--product_id', |
| 3402 | help=('Path to Product ID file'), |
| 3403 | type=argparse.FileType('rb'), |
| 3404 | required=True) |
| 3405 | sub_parser.set_defaults(func=self.make_atx_permanent_attributes) |
| 3406 | |
| 3407 | sub_parser = subparsers.add_parser( |
| 3408 | 'make_atx_metadata', |
| 3409 | help='Create Android Things eXtension (ATX) metadata.') |
| 3410 | sub_parser.add_argument('--output', |
| 3411 | help='Write metadata to file', |
| 3412 | type=argparse.FileType('wb'), |
| 3413 | default=sys.stdout) |
| 3414 | sub_parser.add_argument('--intermediate_key_certificate', |
| 3415 | help='Path to intermediate key certificate file', |
| 3416 | type=argparse.FileType('rb'), |
| 3417 | required=True) |
| 3418 | sub_parser.add_argument('--product_key_certificate', |
| 3419 | help='Path to product key certificate file', |
| 3420 | type=argparse.FileType('rb'), |
| 3421 | required=True) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3422 | sub_parser.set_defaults(func=self.make_atx_metadata) |
| 3423 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3424 | args = parser.parse_args(argv[1:]) |
| 3425 | try: |
| 3426 | args.func(args) |
| 3427 | except AvbError as e: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3428 | sys.stderr.write('{}: {}\n'.format(argv[0], e.message)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3429 | sys.exit(1) |
| 3430 | |
| 3431 | def version(self, _): |
| 3432 | """Implements the 'version' sub-command.""" |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 3433 | print get_release_string() |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3434 | |
| 3435 | def extract_public_key(self, args): |
| 3436 | """Implements the 'extract_public_key' sub-command.""" |
| 3437 | self.avb.extract_public_key(args.key, args.output) |
| 3438 | |
| 3439 | def make_vbmeta_image(self, args): |
| 3440 | """Implements the 'make_vbmeta_image' sub-command.""" |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3441 | args = self._fixup_common_args(args) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3442 | self.avb.make_vbmeta_image(args.output, args.chain_partition, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 3443 | args.algorithm, args.key, |
| 3444 | args.public_key_metadata, args.rollback_index, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 3445 | args.flags, args.prop, args.prop_from_file, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3446 | args.kernel_cmdline, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 3447 | args.setup_rootfs_from_kernel, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3448 | args.include_descriptors_from_image, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 3449 | args.signing_helper, |
| 3450 | args.internal_release_string, |
| 3451 | args.append_to_release_string) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3452 | |
David Zeuthen | b1b994d | 2017-03-06 18:01:31 -0500 | [diff] [blame] | 3453 | def append_vbmeta_image(self, args): |
| 3454 | """Implements the 'append_vbmeta_image' sub-command.""" |
| 3455 | self.avb.append_vbmeta_image(args.image.name, args.vbmeta_image.name, |
| 3456 | args.partition_size) |
| 3457 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3458 | def add_hash_footer(self, args): |
| 3459 | """Implements the 'add_hash_footer' sub-command.""" |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3460 | args = self._fixup_common_args(args) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3461 | self.avb.add_hash_footer(args.image.name, args.partition_size, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3462 | args.partition_name, args.hash_algorithm, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3463 | args.salt, args.chain_partition, args.algorithm, |
| 3464 | args.key, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 3465 | args.public_key_metadata, args.rollback_index, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3466 | args.flags, args.prop, args.prop_from_file, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 3467 | args.kernel_cmdline, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 3468 | args.setup_rootfs_from_kernel, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3469 | args.include_descriptors_from_image, |
| 3470 | args.signing_helper, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 3471 | args.internal_release_string, |
| 3472 | args.append_to_release_string, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3473 | args.output_vbmeta_image, |
| 3474 | args.do_not_append_vbmeta_image) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3475 | |
| 3476 | def add_hashtree_footer(self, args): |
| 3477 | """Implements the 'add_hashtree_footer' sub-command.""" |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3478 | args = self._fixup_common_args(args) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3479 | self.avb.add_hashtree_footer(args.image.name if args.image else None, |
| 3480 | args.partition_size, |
| 3481 | args.partition_name, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 3482 | args.generate_fec, args.fec_num_roots, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3483 | args.hash_algorithm, args.block_size, |
David Zeuthen | a5fd3a4 | 2017-02-27 16:38:54 -0500 | [diff] [blame] | 3484 | args.salt, args.chain_partition, args.algorithm, |
| 3485 | args.key, args.public_key_metadata, |
| 3486 | args.rollback_index, args.flags, args.prop, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3487 | args.prop_from_file, |
| 3488 | args.kernel_cmdline, |
David Zeuthen | 5d4f4f2 | 2017-01-11 11:37:34 -0500 | [diff] [blame] | 3489 | args.setup_rootfs_from_kernel, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 3490 | args.include_descriptors_from_image, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3491 | args.calc_max_image_size, args.signing_helper, |
David Zeuthen | e3cadca | 2017-02-22 21:25:46 -0500 | [diff] [blame] | 3492 | args.internal_release_string, |
| 3493 | args.append_to_release_string, |
David Zeuthen | d247fcb | 2017-02-16 12:09:27 -0500 | [diff] [blame] | 3494 | args.output_vbmeta_image, |
| 3495 | args.do_not_append_vbmeta_image) |
| 3496 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3497 | def erase_footer(self, args): |
| 3498 | """Implements the 'erase_footer' sub-command.""" |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3499 | self.avb.erase_footer(args.image.name, args.keep_hashtree) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3500 | |
David Zeuthen | 2bc232b | 2017-04-19 14:25:19 -0400 | [diff] [blame] | 3501 | def resize_image(self, args): |
| 3502 | """Implements the 'resize_image' sub-command.""" |
| 3503 | self.avb.resize_image(args.image.name, args.partition_size) |
| 3504 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 3505 | def set_ab_metadata(self, args): |
| 3506 | """Implements the 'set_ab_metadata' sub-command.""" |
| 3507 | self.avb.set_ab_metadata(args.misc_image, args.slot_data) |
| 3508 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3509 | def info_image(self, args): |
| 3510 | """Implements the 'info_image' sub-command.""" |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 3511 | self.avb.info_image(args.image.name, args.output) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3512 | |
David Zeuthen | b623d8b | 2017-04-04 16:05:53 -0400 | [diff] [blame] | 3513 | def verify_image(self, args): |
| 3514 | """Implements the 'verify_image' sub-command.""" |
| 3515 | self.avb.verify_image(args.image.name) |
| 3516 | |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3517 | def make_atx_certificate(self, args): |
| 3518 | """Implements the 'make_atx_certificate' sub-command.""" |
| 3519 | self.avb.make_atx_certificate(args.output, args.authority_key, |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 3520 | args.subject_key.name, |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3521 | args.subject_key_version, |
| 3522 | args.subject.read(), |
| 3523 | args.subject_is_intermediate_authority, |
| 3524 | args.signing_helper) |
| 3525 | |
| 3526 | def make_atx_permanent_attributes(self, args): |
| 3527 | """Implements the 'make_atx_permanent_attributes' sub-command.""" |
| 3528 | self.avb.make_atx_permanent_attributes(args.output, |
David Zeuthen | c68f082 | 2017-03-31 17:22:35 -0400 | [diff] [blame] | 3529 | args.root_authority_key.name, |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3530 | args.product_id.read()) |
| 3531 | |
| 3532 | def make_atx_metadata(self, args): |
| 3533 | """Implements the 'make_atx_metadata' sub-command.""" |
| 3534 | self.avb.make_atx_metadata(args.output, |
| 3535 | args.intermediate_key_certificate.read(), |
Darren Krahn | 43e12d8 | 2017-02-24 16:26:31 -0800 | [diff] [blame] | 3536 | args.product_key_certificate.read()) |
Darren Krahn | 147b08d | 2016-12-20 16:38:29 -0800 | [diff] [blame] | 3537 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 3538 | |
| 3539 | if __name__ == '__main__': |
| 3540 | tool = AvbTool() |
| 3541 | tool.run(sys.argv) |