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 |
| 31 | import os |
| 32 | import struct |
| 33 | import subprocess |
| 34 | import sys |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 35 | import tempfile |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 36 | |
| 37 | import Crypto.PublicKey.RSA |
| 38 | |
| 39 | # Keep in sync with avb_vbmeta_header.h. |
| 40 | AVB_VERSION_MAJOR = 1 |
| 41 | AVB_VERSION_MINOR = 0 |
| 42 | |
| 43 | |
| 44 | class AvbError(Exception): |
| 45 | """Application-specific errors. |
| 46 | |
| 47 | These errors represent issues for which a stack-trace should not be |
| 48 | presented. |
| 49 | |
| 50 | Attributes: |
| 51 | message: Error message. |
| 52 | """ |
| 53 | |
| 54 | def __init__(self, message): |
| 55 | Exception.__init__(self, message) |
| 56 | |
| 57 | |
| 58 | class Algorithm(object): |
| 59 | """Contains details about an algorithm. |
| 60 | |
| 61 | See the avb_vbmeta_header.h file for more details about |
| 62 | algorithms. |
| 63 | |
| 64 | The constant |ALGORITHMS| is a dictionary from human-readable |
| 65 | names (e.g 'SHA256_RSA2048') to instances of this class. |
| 66 | |
| 67 | Attributes: |
| 68 | algorithm_type: Integer code corresponding to |AvbAlgorithmType|. |
| 69 | hash_num_bytes: Number of bytes used to store the hash. |
| 70 | signature_num_bytes: Number of bytes used to store the signature. |
| 71 | public_key_num_bytes: Number of bytes used to store the public key. |
| 72 | padding: Padding used for signature, if any. |
| 73 | """ |
| 74 | |
| 75 | def __init__(self, algorithm_type, hash_num_bytes, signature_num_bytes, |
| 76 | public_key_num_bytes, padding): |
| 77 | self.algorithm_type = algorithm_type |
| 78 | self.hash_num_bytes = hash_num_bytes |
| 79 | self.signature_num_bytes = signature_num_bytes |
| 80 | self.public_key_num_bytes = public_key_num_bytes |
| 81 | self.padding = padding |
| 82 | |
| 83 | # This must be kept in sync with the avb_crypto.h file. |
| 84 | # |
| 85 | # The PKC1-v1.5 padding is a blob of binary DER of ASN.1 and is |
| 86 | # obtained from section 5.2.2 of RFC 4880. |
| 87 | ALGORITHMS = { |
| 88 | 'NONE': Algorithm( |
| 89 | algorithm_type=0, # AVB_ALGORITHM_TYPE_NONE |
| 90 | hash_num_bytes=0, |
| 91 | signature_num_bytes=0, |
| 92 | public_key_num_bytes=0, |
| 93 | padding=[]), |
| 94 | 'SHA256_RSA2048': Algorithm( |
| 95 | algorithm_type=1, # AVB_ALGORITHM_TYPE_SHA256_RSA2048 |
| 96 | hash_num_bytes=32, |
| 97 | signature_num_bytes=256, |
| 98 | public_key_num_bytes=8 + 2*2048/8, |
| 99 | padding=[ |
| 100 | # PKCS1-v1_5 padding |
| 101 | 0x00, 0x01] + [0xff]*202 + [0x00] + [ |
| 102 | # ASN.1 header |
| 103 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 104 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 105 | 0x00, 0x04, 0x20, |
| 106 | ]), |
| 107 | 'SHA256_RSA4096': Algorithm( |
| 108 | algorithm_type=2, # AVB_ALGORITHM_TYPE_SHA256_RSA4096 |
| 109 | hash_num_bytes=32, |
| 110 | signature_num_bytes=512, |
| 111 | public_key_num_bytes=8 + 2*4096/8, |
| 112 | padding=[ |
| 113 | # PKCS1-v1_5 padding |
| 114 | 0x00, 0x01] + [0xff]*458 + [0x00] + [ |
| 115 | # ASN.1 header |
| 116 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 117 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 118 | 0x00, 0x04, 0x20, |
| 119 | ]), |
| 120 | 'SHA256_RSA8192': Algorithm( |
| 121 | algorithm_type=3, # AVB_ALGORITHM_TYPE_SHA256_RSA8192 |
| 122 | hash_num_bytes=32, |
| 123 | signature_num_bytes=1024, |
| 124 | public_key_num_bytes=8 + 2*8192/8, |
| 125 | padding=[ |
| 126 | # PKCS1-v1_5 padding |
| 127 | 0x00, 0x01] + [0xff]*970 + [0x00] + [ |
| 128 | # ASN.1 header |
| 129 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 130 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, |
| 131 | 0x00, 0x04, 0x20, |
| 132 | ]), |
| 133 | 'SHA512_RSA2048': Algorithm( |
| 134 | algorithm_type=4, # AVB_ALGORITHM_TYPE_SHA512_RSA2048 |
| 135 | hash_num_bytes=64, |
| 136 | signature_num_bytes=256, |
| 137 | public_key_num_bytes=8 + 2*2048/8, |
| 138 | padding=[ |
| 139 | # PKCS1-v1_5 padding |
| 140 | 0x00, 0x01] + [0xff]*170 + [0x00] + [ |
| 141 | # ASN.1 header |
| 142 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 143 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 144 | 0x00, 0x04, 0x40 |
| 145 | ]), |
| 146 | 'SHA512_RSA4096': Algorithm( |
| 147 | algorithm_type=5, # AVB_ALGORITHM_TYPE_SHA512_RSA4096 |
| 148 | hash_num_bytes=64, |
| 149 | signature_num_bytes=512, |
| 150 | public_key_num_bytes=8 + 2*4096/8, |
| 151 | padding=[ |
| 152 | # PKCS1-v1_5 padding |
| 153 | 0x00, 0x01] + [0xff]*426 + [0x00] + [ |
| 154 | # ASN.1 header |
| 155 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 156 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 157 | 0x00, 0x04, 0x40 |
| 158 | ]), |
| 159 | 'SHA512_RSA8192': Algorithm( |
| 160 | algorithm_type=6, # AVB_ALGORITHM_TYPE_SHA512_RSA8192 |
| 161 | hash_num_bytes=64, |
| 162 | signature_num_bytes=1024, |
| 163 | public_key_num_bytes=8 + 2*8192/8, |
| 164 | padding=[ |
| 165 | # PKCS1-v1_5 padding |
| 166 | 0x00, 0x01] + [0xff]*938 + [0x00] + [ |
| 167 | # ASN.1 header |
| 168 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, |
| 169 | 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, |
| 170 | 0x00, 0x04, 0x40 |
| 171 | ]), |
| 172 | } |
| 173 | |
| 174 | |
| 175 | def round_to_multiple(number, size): |
| 176 | """Rounds a number up to nearest multiple of another number. |
| 177 | |
| 178 | Args: |
| 179 | number: The number to round up. |
| 180 | size: The multiple to round up to. |
| 181 | |
| 182 | Returns: |
| 183 | If |number| is a multiple of |size|, returns |number|, otherwise |
| 184 | returns |number| + |size|. |
| 185 | """ |
| 186 | remainder = number % size |
| 187 | if remainder == 0: |
| 188 | return number |
| 189 | return number + size - remainder |
| 190 | |
| 191 | |
| 192 | def round_to_pow2(number): |
| 193 | """Rounds a number up to the next power of 2. |
| 194 | |
| 195 | Args: |
| 196 | number: The number to round up. |
| 197 | |
| 198 | Returns: |
| 199 | If |number| is already a power of 2 then |number| is |
| 200 | returned. Otherwise the smallest power of 2 greater than |number| |
| 201 | is returned. |
| 202 | """ |
| 203 | return 2**((number - 1).bit_length()) |
| 204 | |
| 205 | |
| 206 | def write_long(output, num_bits, value): |
| 207 | """Writes a long to an output stream using a given amount of bits. |
| 208 | |
| 209 | This number is written big-endian, e.g. with the most significant |
| 210 | bit first. |
| 211 | |
| 212 | Arguments: |
| 213 | output: The object to write the output to. |
| 214 | num_bits: The number of bits to write, e.g. 2048. |
| 215 | value: The value to write. |
| 216 | """ |
| 217 | for bit_pos in range(num_bits, 0, -8): |
| 218 | octet = (value >> (bit_pos - 8)) & 0xff |
| 219 | output.write(struct.pack('!B', octet)) |
| 220 | |
| 221 | |
| 222 | def encode_long(num_bits, value): |
| 223 | """Encodes a long to a bytearray() using a given amount of bits. |
| 224 | |
| 225 | This number is written big-endian, e.g. with the most significant |
| 226 | bit first. |
| 227 | |
| 228 | Arguments: |
| 229 | num_bits: The number of bits to write, e.g. 2048. |
| 230 | value: The value to write. |
| 231 | |
| 232 | Returns: |
| 233 | A bytearray() with the encoded long. |
| 234 | """ |
| 235 | ret = bytearray() |
| 236 | for bit_pos in range(num_bits, 0, -8): |
| 237 | octet = (value >> (bit_pos - 8)) & 0xff |
| 238 | ret.extend(struct.pack('!B', octet)) |
| 239 | return ret |
| 240 | |
| 241 | |
| 242 | def egcd(a, b): |
| 243 | """Calculate greatest common divisor of two numbers. |
| 244 | |
| 245 | This implementation uses a recursive version of the extended |
| 246 | Euclidian algorithm. |
| 247 | |
| 248 | Arguments: |
| 249 | a: First number. |
| 250 | b: Second number. |
| 251 | |
| 252 | Returns: |
| 253 | A tuple (gcd, x, y) that where |gcd| is the greatest common |
| 254 | divisor of |a| and |b| and |a|*|x| + |b|*|y| = |gcd|. |
| 255 | """ |
| 256 | if a == 0: |
| 257 | return (b, 0, 1) |
| 258 | else: |
| 259 | g, y, x = egcd(b % a, a) |
| 260 | return (g, x - (b // a) * y, y) |
| 261 | |
| 262 | |
| 263 | def modinv(a, m): |
| 264 | """Calculate modular multiplicative inverse of |a| modulo |m|. |
| 265 | |
| 266 | This calculates the number |x| such that |a| * |x| == 1 (modulo |
| 267 | |m|). This number only exists if |a| and |m| are co-prime - |None| |
| 268 | is returned if this isn't true. |
| 269 | |
| 270 | Arguments: |
| 271 | a: The number to calculate a modular inverse of. |
| 272 | m: The modulo to use. |
| 273 | |
| 274 | Returns: |
| 275 | The modular multiplicative inverse of |a| and |m| or |None| if |
| 276 | these numbers are not co-prime. |
| 277 | """ |
| 278 | gcd, x, _ = egcd(a, m) |
| 279 | if gcd != 1: |
| 280 | return None # modular inverse does not exist |
| 281 | else: |
| 282 | return x % m |
| 283 | |
| 284 | |
| 285 | def parse_number(string): |
| 286 | """Parse a string as a number. |
| 287 | |
| 288 | This is just a short-hand for int(string, 0) suitable for use in the |
| 289 | |type| parameter of |ArgumentParser|'s add_argument() function. An |
| 290 | improvement to just using type=int is that this function supports |
| 291 | numbers in other bases, e.g. "0x1234". |
| 292 | |
| 293 | Arguments: |
| 294 | string: The string to parse. |
| 295 | |
| 296 | Returns: |
| 297 | The parsed integer. |
| 298 | |
| 299 | Raises: |
| 300 | ValueError: If the number could not be parsed. |
| 301 | """ |
| 302 | return int(string, 0) |
| 303 | |
| 304 | |
| 305 | def write_rsa_key(output, key): |
| 306 | """Writes a public RSA key in |AvbRSAPublicKeyHeader| format. |
| 307 | |
| 308 | This writes the |AvbRSAPublicKeyHeader| as well as the two large |
| 309 | numbers (|key_num_bits| bits long) following it. |
| 310 | |
| 311 | Arguments: |
| 312 | output: The object to write the output to. |
| 313 | key: A Crypto.PublicKey.RSA object. |
| 314 | """ |
| 315 | # key.e is exponent |
| 316 | # key.n is modulus |
| 317 | key_num_bits = key.size() + 1 |
| 318 | # Calculate n0inv = -1/n[0] (mod 2^32) |
| 319 | b = 2L**32 |
| 320 | n0inv = b - modinv(key.n, b) |
| 321 | # Calculate rr = r^2 (mod N), where r = 2^(# of key bits) |
| 322 | r = 2L**key.n.bit_length() |
| 323 | rrmodn = r * r % key.n |
| 324 | output.write(struct.pack('!II', key_num_bits, n0inv)) |
| 325 | write_long(output, key_num_bits, key.n) |
| 326 | write_long(output, key_num_bits, rrmodn) |
| 327 | |
| 328 | |
| 329 | def encode_rsa_key(key): |
| 330 | """Encodes a public RSA key in |AvbRSAPublicKeyHeader| format. |
| 331 | |
| 332 | This creates a |AvbRSAPublicKeyHeader| as well as the two large |
| 333 | numbers (|key_num_bits| bits long) following it. |
| 334 | |
| 335 | Arguments: |
| 336 | key: A Crypto.PublicKey.RSA object. |
| 337 | |
| 338 | Returns: |
| 339 | A bytearray() with the |AvbRSAPublicKeyHeader|. |
| 340 | """ |
| 341 | ret = bytearray() |
| 342 | # key.e is exponent |
| 343 | # key.n is modulus |
| 344 | key_num_bits = key.size() + 1 |
| 345 | # Calculate n0inv = -1/n[0] (mod 2^32) |
| 346 | b = 2L**32 |
| 347 | n0inv = b - modinv(key.n, b) |
| 348 | # Calculate rr = r^2 (mod N), where r = 2^(# of key bits) |
| 349 | r = 2L**key.n.bit_length() |
| 350 | rrmodn = r * r % key.n |
| 351 | ret.extend(struct.pack('!II', key_num_bits, n0inv)) |
| 352 | ret.extend(encode_long(key_num_bits, key.n)) |
| 353 | ret.extend(encode_long(key_num_bits, rrmodn)) |
| 354 | return ret |
| 355 | |
| 356 | |
| 357 | def lookup_algorithm_by_type(alg_type): |
| 358 | """Looks up algorithm by type. |
| 359 | |
| 360 | Arguments: |
| 361 | alg_type: The integer representing the type. |
| 362 | |
| 363 | Returns: |
| 364 | A tuple with the algorithm name and an |Algorithm| instance. |
| 365 | |
| 366 | Raises: |
| 367 | Exception: If the algorithm cannot be found |
| 368 | """ |
| 369 | for alg_name in ALGORITHMS: |
| 370 | alg_data = ALGORITHMS[alg_name] |
| 371 | if alg_data.algorithm_type == alg_type: |
| 372 | return (alg_name, alg_data) |
| 373 | raise AvbError('Unknown algorithm type {}'.format(alg_type)) |
| 374 | |
| 375 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 376 | class ImageChunk(object): |
| 377 | """Data structure used for representing chunks in Android sparse files. |
| 378 | |
| 379 | Attributes: |
| 380 | chunk_type: One of TYPE_RAW, TYPE_FILL, or TYPE_DONT_CARE. |
| 381 | chunk_offset: Offset in the sparse file where this chunk begins. |
| 382 | output_offset: Offset in de-sparsified file where output begins. |
| 383 | output_size: Number of bytes in output. |
| 384 | input_offset: Offset in sparse file for data if TYPE_RAW otherwise None. |
| 385 | fill_data: Blob with data to fill if TYPE_FILL otherwise None. |
| 386 | """ |
| 387 | |
| 388 | FORMAT = '<2H2I' |
| 389 | TYPE_RAW = 0xcac1 |
| 390 | TYPE_FILL = 0xcac2 |
| 391 | TYPE_DONT_CARE = 0xcac3 |
| 392 | TYPE_CRC32 = 0xcac4 |
| 393 | |
| 394 | def __init__(self, chunk_type, chunk_offset, output_offset, output_size, |
| 395 | input_offset, fill_data): |
| 396 | """Initializes an ImageChunk object. |
| 397 | |
| 398 | Arguments: |
| 399 | chunk_type: One of TYPE_RAW, TYPE_FILL, or TYPE_DONT_CARE. |
| 400 | chunk_offset: Offset in the sparse file where this chunk begins. |
| 401 | output_offset: Offset in de-sparsified file. |
| 402 | output_size: Number of bytes in output. |
| 403 | input_offset: Offset in sparse file if TYPE_RAW otherwise None. |
| 404 | fill_data: Blob with data to fill if TYPE_FILL otherwise None. |
| 405 | |
| 406 | Raises: |
| 407 | ValueError: If data is not well-formed. |
| 408 | """ |
| 409 | self.chunk_type = chunk_type |
| 410 | self.chunk_offset = chunk_offset |
| 411 | self.output_offset = output_offset |
| 412 | self.output_size = output_size |
| 413 | self.input_offset = input_offset |
| 414 | self.fill_data = fill_data |
| 415 | # Check invariants. |
| 416 | if self.chunk_type == self.TYPE_RAW: |
| 417 | if self.fill_data is not None: |
| 418 | raise ValueError('RAW chunk cannot have fill_data set.') |
| 419 | if not self.input_offset: |
| 420 | raise ValueError('RAW chunk must have input_offset set.') |
| 421 | elif self.chunk_type == self.TYPE_FILL: |
| 422 | if self.fill_data is None: |
| 423 | raise ValueError('FILL chunk must have fill_data set.') |
| 424 | if self.input_offset: |
| 425 | raise ValueError('FILL chunk cannot have input_offset set.') |
| 426 | elif self.chunk_type == self.TYPE_DONT_CARE: |
| 427 | if self.fill_data is not None: |
| 428 | raise ValueError('DONT_CARE chunk cannot have fill_data set.') |
| 429 | if self.input_offset: |
| 430 | raise ValueError('DONT_CARE chunk cannot have input_offset set.') |
| 431 | else: |
| 432 | raise ValueError('Invalid chunk type') |
| 433 | |
| 434 | |
| 435 | class ImageHandler(object): |
| 436 | """Abstraction for image I/O with support for Android sparse images. |
| 437 | |
| 438 | This class provides an interface for working with image files that |
| 439 | may be using the Android Sparse Image format. When an instance is |
| 440 | constructed, we test whether it's an Android sparse file. If so, |
| 441 | operations will be on the sparse file by interpreting the sparse |
| 442 | format, otherwise they will be directly on the file. Either way the |
| 443 | operations do the same. |
| 444 | |
| 445 | For reading, this interface mimics a file object - it has seek(), |
| 446 | tell(), and read() methods. For writing, only truncation |
| 447 | (truncate()) and appending is supported (append_raw() and |
| 448 | append_dont_care()). Additionally, data can only be written in units |
| 449 | of the block size. |
| 450 | |
| 451 | Attributes: |
| 452 | is_sparse: Whether the file being operated on is sparse. |
| 453 | block_size: The block size, typically 4096. |
| 454 | image_size: The size of the unsparsified file. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 455 | """ |
| 456 | # See system/core/libsparse/sparse_format.h for details. |
| 457 | MAGIC = 0xed26ff3a |
| 458 | HEADER_FORMAT = '<I4H4I' |
| 459 | |
| 460 | # These are formats and offset of just the |total_chunks| and |
| 461 | # |total_blocks| fields. |
| 462 | NUM_CHUNKS_AND_BLOCKS_FORMAT = '<II' |
| 463 | NUM_CHUNKS_AND_BLOCKS_OFFSET = 16 |
| 464 | |
| 465 | def __init__(self, image_filename): |
| 466 | """Initializes an image handler. |
| 467 | |
| 468 | Arguments: |
| 469 | image_filename: The name of the file to operate on. |
| 470 | |
| 471 | Raises: |
| 472 | ValueError: If data in the file is invalid. |
| 473 | """ |
| 474 | self._image_filename = image_filename |
| 475 | self._read_header() |
| 476 | |
| 477 | def _read_header(self): |
| 478 | """Initializes internal data structures used for reading file. |
| 479 | |
| 480 | This may be called multiple times and is typically called after |
| 481 | modifying the file (e.g. appending, truncation). |
| 482 | |
| 483 | Raises: |
| 484 | ValueError: If data in the file is invalid. |
| 485 | """ |
| 486 | self.is_sparse = False |
| 487 | self.block_size = 4096 |
| 488 | self._file_pos = 0 |
| 489 | self._image = open(self._image_filename, 'r+b') |
| 490 | self._image.seek(0, os.SEEK_END) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 491 | self.image_size = self._image.tell() |
| 492 | |
| 493 | self._image.seek(0, os.SEEK_SET) |
| 494 | header_bin = self._image.read(struct.calcsize(self.HEADER_FORMAT)) |
| 495 | (magic, major_version, minor_version, file_hdr_sz, chunk_hdr_sz, |
| 496 | block_size, self._num_total_blocks, self._num_total_chunks, |
| 497 | _) = struct.unpack(self.HEADER_FORMAT, header_bin) |
| 498 | if magic != self.MAGIC: |
| 499 | # Not a sparse image, our job here is done. |
| 500 | return |
| 501 | if not (major_version == 1 and minor_version == 0): |
| 502 | raise ValueError('Encountered sparse image format version {}.{} but ' |
| 503 | 'only 1.0 is supported'.format(major_version, |
| 504 | minor_version)) |
| 505 | if file_hdr_sz != struct.calcsize(self.HEADER_FORMAT): |
| 506 | raise ValueError('Unexpected file_hdr_sz value {}.'. |
| 507 | format(file_hdr_sz)) |
| 508 | if chunk_hdr_sz != struct.calcsize(ImageChunk.FORMAT): |
| 509 | raise ValueError('Unexpected chunk_hdr_sz value {}.'. |
| 510 | format(chunk_hdr_sz)) |
| 511 | |
| 512 | self.block_size = block_size |
| 513 | |
| 514 | # Build an list of chunks by parsing the file. |
| 515 | self._chunks = [] |
| 516 | |
| 517 | # Find the smallest offset where only "Don't care" chunks |
| 518 | # follow. This will be the size of the content in the sparse |
| 519 | # image. |
| 520 | offset = 0 |
| 521 | output_offset = 0 |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 522 | for _ in xrange(1, self._num_total_chunks + 1): |
| 523 | chunk_offset = self._image.tell() |
| 524 | |
| 525 | header_bin = self._image.read(struct.calcsize(ImageChunk.FORMAT)) |
| 526 | (chunk_type, _, chunk_sz, total_sz) = struct.unpack(ImageChunk.FORMAT, |
| 527 | header_bin) |
| 528 | data_sz = total_sz - struct.calcsize(ImageChunk.FORMAT) |
| 529 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 530 | if chunk_type == ImageChunk.TYPE_RAW: |
| 531 | if data_sz != (chunk_sz * self.block_size): |
| 532 | raise ValueError('Raw chunk input size ({}) does not match output ' |
| 533 | 'size ({})'. |
| 534 | format(data_sz, chunk_sz*self.block_size)) |
| 535 | self._chunks.append(ImageChunk(ImageChunk.TYPE_RAW, |
| 536 | chunk_offset, |
| 537 | output_offset, |
| 538 | chunk_sz*self.block_size, |
| 539 | self._image.tell(), |
| 540 | None)) |
| 541 | self._image.read(data_sz) |
| 542 | |
| 543 | elif chunk_type == ImageChunk.TYPE_FILL: |
| 544 | if data_sz != 4: |
| 545 | raise ValueError('Fill chunk should have 4 bytes of fill, but this ' |
| 546 | 'has {}'.format(data_sz)) |
| 547 | fill_data = self._image.read(4) |
| 548 | self._chunks.append(ImageChunk(ImageChunk.TYPE_FILL, |
| 549 | chunk_offset, |
| 550 | output_offset, |
| 551 | chunk_sz*self.block_size, |
| 552 | None, |
| 553 | fill_data)) |
| 554 | elif chunk_type == ImageChunk.TYPE_DONT_CARE: |
| 555 | if data_sz != 0: |
| 556 | raise ValueError('Don\'t care chunk input size is non-zero ({})'. |
| 557 | format(data_sz)) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 558 | self._chunks.append(ImageChunk(ImageChunk.TYPE_DONT_CARE, |
| 559 | chunk_offset, |
| 560 | output_offset, |
| 561 | chunk_sz*self.block_size, |
| 562 | None, |
| 563 | None)) |
| 564 | elif chunk_type == ImageChunk.TYPE_CRC32: |
| 565 | if data_sz != 4: |
| 566 | raise ValueError('CRC32 chunk should have 4 bytes of CRC, but ' |
| 567 | 'this has {}'.format(data_sz)) |
| 568 | self._image.read(4) |
| 569 | else: |
| 570 | raise ValueError('Unknown chunk type {}'.format(chunk_type)) |
| 571 | |
| 572 | offset += chunk_sz |
| 573 | output_offset += chunk_sz*self.block_size |
| 574 | |
| 575 | # Record where sparse data end. |
| 576 | self._sparse_end = self._image.tell() |
| 577 | |
| 578 | # Now that we've traversed all chunks, sanity check. |
| 579 | if self._num_total_blocks != offset: |
| 580 | raise ValueError('The header said we should have {} output blocks, ' |
| 581 | 'but we saw {}'.format(self._num_total_blocks, offset)) |
| 582 | junk_len = len(self._image.read()) |
| 583 | if junk_len > 0: |
| 584 | raise ValueError('There were {} bytes of extra data at the end of the ' |
| 585 | 'file.'.format(junk_len)) |
| 586 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 587 | # Assign |image_size|. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 588 | self.image_size = output_offset |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 589 | |
| 590 | # This is used when bisecting in read() to find the initial slice. |
| 591 | self._chunk_output_offsets = [i.output_offset for i in self._chunks] |
| 592 | |
| 593 | self.is_sparse = True |
| 594 | |
| 595 | def _update_chunks_and_blocks(self): |
| 596 | """Helper function to update the image header. |
| 597 | |
| 598 | The the |total_chunks| and |total_blocks| fields in the header |
| 599 | will be set to value of the |_num_total_blocks| and |
| 600 | |_num_total_chunks| attributes. |
| 601 | |
| 602 | """ |
| 603 | self._image.seek(self.NUM_CHUNKS_AND_BLOCKS_OFFSET, os.SEEK_SET) |
| 604 | self._image.write(struct.pack(self.NUM_CHUNKS_AND_BLOCKS_FORMAT, |
| 605 | self._num_total_blocks, |
| 606 | self._num_total_chunks)) |
| 607 | |
| 608 | def append_dont_care(self, num_bytes): |
| 609 | """Appends a DONT_CARE chunk to the sparse file. |
| 610 | |
| 611 | The given number of bytes must be a multiple of the block size. |
| 612 | |
| 613 | Arguments: |
| 614 | num_bytes: Size in number of bytes of the DONT_CARE chunk. |
| 615 | """ |
| 616 | assert num_bytes % self.block_size == 0 |
| 617 | |
| 618 | if not self.is_sparse: |
| 619 | self._image.seek(0, os.SEEK_END) |
| 620 | # This is more efficient that writing NUL bytes since it'll add |
| 621 | # a hole on file systems that support sparse files (native |
| 622 | # sparse, not Android sparse). |
| 623 | self._image.truncate(self._image.tell() + num_bytes) |
| 624 | self._read_header() |
| 625 | return |
| 626 | |
| 627 | self._num_total_chunks += 1 |
| 628 | self._num_total_blocks += num_bytes / self.block_size |
| 629 | self._update_chunks_and_blocks() |
| 630 | |
| 631 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 632 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 633 | ImageChunk.TYPE_DONT_CARE, |
| 634 | 0, # Reserved |
| 635 | num_bytes / self.block_size, |
| 636 | struct.calcsize(ImageChunk.FORMAT))) |
| 637 | self._read_header() |
| 638 | |
| 639 | def append_raw(self, data): |
| 640 | """Appends a RAW chunk to the sparse file. |
| 641 | |
| 642 | The length of the given data must be a multiple of the block size. |
| 643 | |
| 644 | Arguments: |
| 645 | data: Data to append. |
| 646 | """ |
| 647 | assert len(data) % self.block_size == 0 |
| 648 | |
| 649 | if not self.is_sparse: |
| 650 | self._image.seek(0, os.SEEK_END) |
| 651 | self._image.write(data) |
| 652 | self._read_header() |
| 653 | return |
| 654 | |
| 655 | self._num_total_chunks += 1 |
| 656 | self._num_total_blocks += len(data) / self.block_size |
| 657 | self._update_chunks_and_blocks() |
| 658 | |
| 659 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 660 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 661 | ImageChunk.TYPE_RAW, |
| 662 | 0, # Reserved |
| 663 | len(data) / self.block_size, |
| 664 | len(data) + |
| 665 | struct.calcsize(ImageChunk.FORMAT))) |
| 666 | self._image.write(data) |
| 667 | self._read_header() |
| 668 | |
| 669 | def append_fill(self, fill_data, size): |
| 670 | """Appends a fill chunk to the sparse file. |
| 671 | |
| 672 | The total length of the fill data must be a multiple of the block size. |
| 673 | |
| 674 | Arguments: |
| 675 | fill_data: Fill data to append - must be four bytes. |
| 676 | size: Number of chunk - must be a multiple of four and the block size. |
| 677 | """ |
| 678 | assert len(fill_data) == 4 |
| 679 | assert size % 4 == 0 |
| 680 | assert size % self.block_size == 0 |
| 681 | |
| 682 | if not self.is_sparse: |
| 683 | self._image.seek(0, os.SEEK_END) |
| 684 | self._image.write(fill_data * (size/4)) |
| 685 | self._read_header() |
| 686 | return |
| 687 | |
| 688 | self._num_total_chunks += 1 |
| 689 | self._num_total_blocks += size / self.block_size |
| 690 | self._update_chunks_and_blocks() |
| 691 | |
| 692 | self._image.seek(self._sparse_end, os.SEEK_SET) |
| 693 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 694 | ImageChunk.TYPE_FILL, |
| 695 | 0, # Reserved |
| 696 | size / self.block_size, |
| 697 | 4 + struct.calcsize(ImageChunk.FORMAT))) |
| 698 | self._image.write(fill_data) |
| 699 | self._read_header() |
| 700 | |
| 701 | def seek(self, offset): |
| 702 | """Sets the cursor position for reading from unsparsified file. |
| 703 | |
| 704 | Arguments: |
| 705 | offset: Offset to seek to from the beginning of the file. |
| 706 | """ |
| 707 | self._file_pos = offset |
| 708 | |
| 709 | def read(self, size): |
| 710 | """Reads data from the unsparsified file. |
| 711 | |
| 712 | This method may return fewer than |size| bytes of data if the end |
| 713 | of the file was encountered. |
| 714 | |
| 715 | The file cursor for reading is advanced by the number of bytes |
| 716 | read. |
| 717 | |
| 718 | Arguments: |
| 719 | size: Number of bytes to read. |
| 720 | |
| 721 | Returns: |
| 722 | The data. |
| 723 | |
| 724 | """ |
| 725 | if not self.is_sparse: |
| 726 | self._image.seek(self._file_pos) |
| 727 | data = self._image.read(size) |
| 728 | self._file_pos += len(data) |
| 729 | return data |
| 730 | |
| 731 | # Iterate over all chunks. |
| 732 | chunk_idx = bisect.bisect_right(self._chunk_output_offsets, |
| 733 | self._file_pos) - 1 |
| 734 | data = bytearray() |
| 735 | to_go = size |
| 736 | while to_go > 0: |
| 737 | chunk = self._chunks[chunk_idx] |
| 738 | chunk_pos_offset = self._file_pos - chunk.output_offset |
| 739 | chunk_pos_to_go = min(chunk.output_size - chunk_pos_offset, to_go) |
| 740 | |
| 741 | if chunk.chunk_type == ImageChunk.TYPE_RAW: |
| 742 | self._image.seek(chunk.input_offset + chunk_pos_offset) |
| 743 | data.extend(self._image.read(chunk_pos_to_go)) |
| 744 | elif chunk.chunk_type == ImageChunk.TYPE_FILL: |
| 745 | all_data = chunk.fill_data*(chunk_pos_to_go/len(chunk.fill_data) + 2) |
| 746 | offset_mod = chunk_pos_offset % len(chunk.fill_data) |
| 747 | data.extend(all_data[offset_mod:(offset_mod + chunk_pos_to_go)]) |
| 748 | else: |
| 749 | assert chunk.chunk_type == ImageChunk.TYPE_DONT_CARE |
| 750 | data.extend('\0' * chunk_pos_to_go) |
| 751 | |
| 752 | to_go -= chunk_pos_to_go |
| 753 | self._file_pos += chunk_pos_to_go |
| 754 | chunk_idx += 1 |
| 755 | # Generate partial read in case of EOF. |
| 756 | if chunk_idx >= len(self._chunks): |
| 757 | break |
| 758 | |
| 759 | return data |
| 760 | |
| 761 | def tell(self): |
| 762 | """Returns the file cursor position for reading from unsparsified file. |
| 763 | |
| 764 | Returns: |
| 765 | The file cursor position for reading. |
| 766 | """ |
| 767 | return self._file_pos |
| 768 | |
| 769 | def truncate(self, size): |
| 770 | """Truncates the unsparsified file. |
| 771 | |
| 772 | Arguments: |
| 773 | size: Desired size of unsparsified file. |
| 774 | |
| 775 | Raises: |
| 776 | ValueError: If desired size isn't a multiple of the block size. |
| 777 | """ |
| 778 | if not self.is_sparse: |
| 779 | self._image.truncate(size) |
| 780 | self._read_header() |
| 781 | return |
| 782 | |
| 783 | if size % self.block_size != 0: |
| 784 | raise ValueError('Cannot truncate to a size which is not a multiple ' |
| 785 | 'of the block size') |
| 786 | |
| 787 | if size == self.image_size: |
| 788 | # Trivial where there's nothing to do. |
| 789 | return |
| 790 | elif size < self.image_size: |
| 791 | chunk_idx = bisect.bisect_right(self._chunk_output_offsets, size) - 1 |
| 792 | chunk = self._chunks[chunk_idx] |
| 793 | if chunk.output_offset != size: |
| 794 | # Truncation in the middle of a trunk - need to keep the chunk |
| 795 | # and modify it. |
| 796 | chunk_idx_for_update = chunk_idx + 1 |
| 797 | num_to_keep = size - chunk.output_offset |
| 798 | assert num_to_keep % self.block_size == 0 |
| 799 | if chunk.chunk_type == ImageChunk.TYPE_RAW: |
| 800 | truncate_at = (chunk.chunk_offset + |
| 801 | struct.calcsize(ImageChunk.FORMAT) + num_to_keep) |
| 802 | data_sz = num_to_keep |
| 803 | elif chunk.chunk_type == ImageChunk.TYPE_FILL: |
| 804 | truncate_at = (chunk.chunk_offset + |
| 805 | struct.calcsize(ImageChunk.FORMAT) + 4) |
| 806 | data_sz = 4 |
| 807 | else: |
| 808 | assert chunk.chunk_type == ImageChunk.TYPE_DONT_CARE |
| 809 | truncate_at = chunk.chunk_offset + struct.calcsize(ImageChunk.FORMAT) |
| 810 | data_sz = 0 |
| 811 | chunk_sz = num_to_keep/self.block_size |
| 812 | total_sz = data_sz + struct.calcsize(ImageChunk.FORMAT) |
| 813 | self._image.seek(chunk.chunk_offset) |
| 814 | self._image.write(struct.pack(ImageChunk.FORMAT, |
| 815 | chunk.chunk_type, |
| 816 | 0, # Reserved |
| 817 | chunk_sz, |
| 818 | total_sz)) |
| 819 | chunk.output_size = num_to_keep |
| 820 | else: |
| 821 | # Truncation at trunk boundary. |
| 822 | truncate_at = chunk.chunk_offset |
| 823 | chunk_idx_for_update = chunk_idx |
| 824 | |
| 825 | self._num_total_chunks = chunk_idx_for_update |
| 826 | self._num_total_blocks = 0 |
| 827 | for i in range(0, chunk_idx_for_update): |
| 828 | self._num_total_blocks += self._chunks[i].output_size / self.block_size |
| 829 | self._update_chunks_and_blocks() |
| 830 | self._image.truncate(truncate_at) |
| 831 | |
| 832 | # We've modified the file so re-read all data. |
| 833 | self._read_header() |
| 834 | else: |
| 835 | # Truncating to grow - just add a DONT_CARE section. |
| 836 | self.append_dont_care(size - self.image_size) |
| 837 | |
| 838 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 839 | class AvbDescriptor(object): |
| 840 | """Class for AVB descriptor. |
| 841 | |
| 842 | See the |AvbDescriptor| C struct for more information. |
| 843 | |
| 844 | Attributes: |
| 845 | tag: The tag identifying what kind of descriptor this is. |
| 846 | data: The data in the descriptor. |
| 847 | """ |
| 848 | |
| 849 | SIZE = 16 |
| 850 | FORMAT_STRING = ('!QQ') # tag, num_bytes_following (descriptor header) |
| 851 | |
| 852 | def __init__(self, data): |
| 853 | """Initializes a new property descriptor. |
| 854 | |
| 855 | Arguments: |
| 856 | data: If not None, must be a bytearray(). |
| 857 | |
| 858 | Raises: |
| 859 | LookupError: If the given descriptor is malformed. |
| 860 | """ |
| 861 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 862 | |
| 863 | if data: |
| 864 | (self.tag, num_bytes_following) = ( |
| 865 | struct.unpack(self.FORMAT_STRING, data[0:self.SIZE])) |
| 866 | self.data = data[self.SIZE:self.SIZE + num_bytes_following] |
| 867 | else: |
| 868 | self.tag = None |
| 869 | self.data = None |
| 870 | |
| 871 | def print_desc(self, o): |
| 872 | """Print the descriptor. |
| 873 | |
| 874 | Arguments: |
| 875 | o: The object to write the output to. |
| 876 | """ |
| 877 | o.write(' Unknown descriptor:\n') |
| 878 | o.write(' Tag: {}\n'.format(self.tag)) |
| 879 | if len(self.data) < 256: |
| 880 | o.write(' Data: {} ({} bytes)\n'.format( |
| 881 | repr(str(self.data)), len(self.data))) |
| 882 | else: |
| 883 | o.write(' Data: {} bytes\n'.format(len(self.data))) |
| 884 | |
| 885 | def encode(self): |
| 886 | """Serializes the descriptor. |
| 887 | |
| 888 | Returns: |
| 889 | A bytearray() with the descriptor data. |
| 890 | """ |
| 891 | num_bytes_following = len(self.data) |
| 892 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 893 | padding_size = nbf_with_padding - num_bytes_following |
| 894 | desc = struct.pack(self.FORMAT_STRING, self.tag, nbf_with_padding) |
| 895 | padding = struct.pack(str(padding_size) + 'x') |
| 896 | ret = desc + self.data + padding |
| 897 | return bytearray(ret) |
| 898 | |
| 899 | |
| 900 | class AvbPropertyDescriptor(AvbDescriptor): |
| 901 | """A class for property descriptors. |
| 902 | |
| 903 | See the |AvbPropertyDescriptor| C struct for more information. |
| 904 | |
| 905 | Attributes: |
| 906 | key: The key. |
| 907 | value: The key. |
| 908 | """ |
| 909 | |
| 910 | TAG = 0 |
| 911 | SIZE = 32 |
| 912 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 913 | 'Q' # key size (bytes) |
| 914 | 'Q') # value size (bytes) |
| 915 | |
| 916 | def __init__(self, data=None): |
| 917 | """Initializes a new property descriptor. |
| 918 | |
| 919 | Arguments: |
| 920 | data: If not None, must be a bytearray of size |SIZE|. |
| 921 | |
| 922 | Raises: |
| 923 | LookupError: If the given descriptor is malformed. |
| 924 | """ |
| 925 | AvbDescriptor.__init__(self, None) |
| 926 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 927 | |
| 928 | if data: |
| 929 | (tag, num_bytes_following, key_size, |
| 930 | value_size) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
| 931 | expected_size = round_to_multiple( |
| 932 | self.SIZE - 16 + key_size + 1 + value_size + 1, 8) |
| 933 | if tag != self.TAG or num_bytes_following != expected_size: |
| 934 | raise LookupError('Given data does not look like a property ' |
| 935 | 'descriptor.') |
| 936 | self.key = data[self.SIZE:(self.SIZE + key_size)] |
| 937 | self.value = data[(self.SIZE + key_size + 1):(self.SIZE + key_size + 1 + |
| 938 | value_size)] |
| 939 | else: |
| 940 | self.key = '' |
| 941 | self.value = '' |
| 942 | |
| 943 | def print_desc(self, o): |
| 944 | """Print the descriptor. |
| 945 | |
| 946 | Arguments: |
| 947 | o: The object to write the output to. |
| 948 | """ |
| 949 | if len(self.value) < 256: |
| 950 | o.write(' Prop: {} -> {}\n'.format(self.key, repr(str(self.value)))) |
| 951 | else: |
| 952 | o.write(' Prop: {} -> ({} bytes)\n'.format(self.key, len(self.value))) |
| 953 | |
| 954 | def encode(self): |
| 955 | """Serializes the descriptor. |
| 956 | |
| 957 | Returns: |
| 958 | A bytearray() with the descriptor data. |
| 959 | """ |
| 960 | num_bytes_following = self.SIZE + len(self.key) + len(self.value) + 2 - 16 |
| 961 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 962 | padding_size = nbf_with_padding - num_bytes_following |
| 963 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 964 | len(self.key), len(self.value)) |
| 965 | padding = struct.pack(str(padding_size) + 'x') |
| 966 | ret = desc + self.key + '\0' + self.value + '\0' + padding |
| 967 | return bytearray(ret) |
| 968 | |
| 969 | |
| 970 | class AvbHashtreeDescriptor(AvbDescriptor): |
| 971 | """A class for hashtree descriptors. |
| 972 | |
| 973 | See the |AvbHashtreeDescriptor| C struct for more information. |
| 974 | |
| 975 | Attributes: |
| 976 | dm_verity_version: dm-verity version used. |
| 977 | image_size: Size of the image, after rounding up to |block_size|. |
| 978 | tree_offset: Offset of the hash tree in the file. |
| 979 | tree_size: Size of the tree. |
| 980 | data_block_size: Data block size |
| 981 | hash_block_size: Hash block size |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 982 | fec_num_roots: Number of roots used for FEC (0 if FEC is not used). |
| 983 | fec_offset: Offset of FEC data (0 if FEC is not used). |
| 984 | fec_size: Size of FEC data (0 if FEC is not used). |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 985 | hash_algorithm: Hash algorithm used. |
| 986 | partition_name: Partition name. |
| 987 | salt: Salt used. |
| 988 | root_digest: Root digest. |
| 989 | """ |
| 990 | |
| 991 | TAG = 1 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 992 | RESERVED = 64 |
| 993 | SIZE = 116 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 994 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 995 | 'L' # dm-verity version used |
| 996 | 'Q' # image size (bytes) |
| 997 | 'Q' # tree offset (bytes) |
| 998 | 'Q' # tree size (bytes) |
| 999 | 'L' # data block size (bytes) |
| 1000 | 'L' # hash block size (bytes) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1001 | 'L' # FEC number of roots |
| 1002 | 'Q' # FEC offset (bytes) |
| 1003 | 'Q' # FEC size (bytes) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1004 | '32s' # hash algorithm used |
| 1005 | 'L' # partition name (bytes) |
| 1006 | 'L' # salt length (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1007 | 'L' + # root digest length (bytes) |
| 1008 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1009 | |
| 1010 | def __init__(self, data=None): |
| 1011 | """Initializes a new hashtree descriptor. |
| 1012 | |
| 1013 | Arguments: |
| 1014 | data: If not None, must be a bytearray of size |SIZE|. |
| 1015 | |
| 1016 | Raises: |
| 1017 | LookupError: If the given descriptor is malformed. |
| 1018 | """ |
| 1019 | AvbDescriptor.__init__(self, None) |
| 1020 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1021 | |
| 1022 | if data: |
| 1023 | (tag, num_bytes_following, self.dm_verity_version, self.image_size, |
| 1024 | self.tree_offset, self.tree_size, self.data_block_size, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1025 | self.hash_block_size, self.fec_num_roots, self.fec_offset, self.fec_size, |
| 1026 | self.hash_algorithm, partition_name_len, salt_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1027 | root_digest_len, _) = struct.unpack(self.FORMAT_STRING, |
| 1028 | data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1029 | expected_size = round_to_multiple( |
| 1030 | self.SIZE - 16 + partition_name_len + salt_len + root_digest_len, 8) |
| 1031 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1032 | raise LookupError('Given data does not look like a hashtree ' |
| 1033 | 'descriptor.') |
| 1034 | # Nuke NUL-bytes at the end. |
| 1035 | self.hash_algorithm = self.hash_algorithm.split('\0', 1)[0] |
| 1036 | o = 0 |
| 1037 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1038 | partition_name_len)]) |
| 1039 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1040 | self.partition_name.decode('utf-8') |
| 1041 | o += partition_name_len |
| 1042 | self.salt = data[(self.SIZE + o):(self.SIZE + o + salt_len)] |
| 1043 | o += salt_len |
| 1044 | self.root_digest = data[(self.SIZE + o):(self.SIZE + o + root_digest_len)] |
| 1045 | if root_digest_len != len(hashlib.new(name=self.hash_algorithm).digest()): |
| 1046 | raise LookupError('root_digest_len doesn\'t match hash algorithm') |
| 1047 | |
| 1048 | else: |
| 1049 | self.dm_verity_version = 0 |
| 1050 | self.image_size = 0 |
| 1051 | self.tree_offset = 0 |
| 1052 | self.tree_size = 0 |
| 1053 | self.data_block_size = 0 |
| 1054 | self.hash_block_size = 0 |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1055 | self.fec_num_roots = 0 |
| 1056 | self.fec_offset = 0 |
| 1057 | self.fec_size = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1058 | self.hash_algorithm = '' |
| 1059 | self.partition_name = '' |
| 1060 | self.salt = bytearray() |
| 1061 | self.root_digest = bytearray() |
| 1062 | |
| 1063 | def print_desc(self, o): |
| 1064 | """Print the descriptor. |
| 1065 | |
| 1066 | Arguments: |
| 1067 | o: The object to write the output to. |
| 1068 | """ |
| 1069 | o.write(' Hashtree descriptor:\n') |
| 1070 | o.write(' Version of dm-verity: {}\n'.format(self.dm_verity_version)) |
| 1071 | o.write(' Image Size: {} bytes\n'.format(self.image_size)) |
| 1072 | o.write(' Tree Offset: {}\n'.format(self.tree_offset)) |
| 1073 | o.write(' Tree Size: {} bytes\n'.format(self.tree_size)) |
| 1074 | o.write(' Data Block Size: {} bytes\n'.format( |
| 1075 | self.data_block_size)) |
| 1076 | o.write(' Hash Block Size: {} bytes\n'.format( |
| 1077 | self.hash_block_size)) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1078 | o.write(' FEC num roots: {}\n'.format(self.fec_num_roots)) |
| 1079 | o.write(' FEC offset: {}\n'.format(self.fec_offset)) |
| 1080 | o.write(' FEC size: {} bytes\n'.format(self.fec_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1081 | o.write(' Hash Algorithm: {}\n'.format(self.hash_algorithm)) |
| 1082 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1083 | o.write(' Salt: {}\n'.format(str(self.salt).encode( |
| 1084 | 'hex'))) |
| 1085 | o.write(' Root Digest: {}\n'.format(str( |
| 1086 | self.root_digest).encode('hex'))) |
| 1087 | |
| 1088 | def encode(self): |
| 1089 | """Serializes the descriptor. |
| 1090 | |
| 1091 | Returns: |
| 1092 | A bytearray() with the descriptor data. |
| 1093 | """ |
| 1094 | encoded_name = self.partition_name.encode('utf-8') |
| 1095 | num_bytes_following = (self.SIZE + len(encoded_name) + len(self.salt) + |
| 1096 | len(self.root_digest) - 16) |
| 1097 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1098 | padding_size = nbf_with_padding - num_bytes_following |
| 1099 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 1100 | self.dm_verity_version, self.image_size, |
| 1101 | self.tree_offset, self.tree_size, self.data_block_size, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1102 | self.hash_block_size, self.fec_num_roots, |
| 1103 | self.fec_offset, self.fec_size, self.hash_algorithm, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1104 | len(encoded_name), len(self.salt), len(self.root_digest), |
| 1105 | self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1106 | padding = struct.pack(str(padding_size) + 'x') |
| 1107 | ret = desc + encoded_name + self.salt + self.root_digest + padding |
| 1108 | return bytearray(ret) |
| 1109 | |
| 1110 | |
| 1111 | class AvbHashDescriptor(AvbDescriptor): |
| 1112 | """A class for hash descriptors. |
| 1113 | |
| 1114 | See the |AvbHashDescriptor| C struct for more information. |
| 1115 | |
| 1116 | Attributes: |
| 1117 | image_size: Image size, in bytes. |
| 1118 | hash_algorithm: Hash algorithm used. |
| 1119 | partition_name: Partition name. |
| 1120 | salt: Salt used. |
| 1121 | digest: The hash value of salt and data combined. |
| 1122 | """ |
| 1123 | |
| 1124 | TAG = 2 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1125 | RESERVED = 64 |
| 1126 | SIZE = 68 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1127 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
| 1128 | 'Q' # image size (bytes) |
| 1129 | '32s' # hash algorithm used |
| 1130 | 'L' # partition name (bytes) |
| 1131 | 'L' # salt length (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1132 | 'L' + # digest length (bytes) |
| 1133 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1134 | |
| 1135 | def __init__(self, data=None): |
| 1136 | """Initializes a new hash descriptor. |
| 1137 | |
| 1138 | Arguments: |
| 1139 | data: If not None, must be a bytearray of size |SIZE|. |
| 1140 | |
| 1141 | Raises: |
| 1142 | LookupError: If the given descriptor is malformed. |
| 1143 | """ |
| 1144 | AvbDescriptor.__init__(self, None) |
| 1145 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1146 | |
| 1147 | if data: |
| 1148 | (tag, num_bytes_following, self.image_size, self.hash_algorithm, |
| 1149 | partition_name_len, salt_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1150 | digest_len, _) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1151 | expected_size = round_to_multiple( |
| 1152 | self.SIZE - 16 + partition_name_len + salt_len + digest_len, 8) |
| 1153 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1154 | raise LookupError('Given data does not look like a hash ' 'descriptor.') |
| 1155 | # Nuke NUL-bytes at the end. |
| 1156 | self.hash_algorithm = self.hash_algorithm.split('\0', 1)[0] |
| 1157 | o = 0 |
| 1158 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1159 | partition_name_len)]) |
| 1160 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1161 | self.partition_name.decode('utf-8') |
| 1162 | o += partition_name_len |
| 1163 | self.salt = data[(self.SIZE + o):(self.SIZE + o + salt_len)] |
| 1164 | o += salt_len |
| 1165 | self.digest = data[(self.SIZE + o):(self.SIZE + o + digest_len)] |
| 1166 | if digest_len != len(hashlib.new(name=self.hash_algorithm).digest()): |
| 1167 | raise LookupError('digest_len doesn\'t match hash algorithm') |
| 1168 | |
| 1169 | else: |
| 1170 | self.image_size = 0 |
| 1171 | self.hash_algorithm = '' |
| 1172 | self.partition_name = '' |
| 1173 | self.salt = bytearray() |
| 1174 | self.digest = bytearray() |
| 1175 | |
| 1176 | def print_desc(self, o): |
| 1177 | """Print the descriptor. |
| 1178 | |
| 1179 | Arguments: |
| 1180 | o: The object to write the output to. |
| 1181 | """ |
| 1182 | o.write(' Hash descriptor:\n') |
| 1183 | o.write(' Image Size: {} bytes\n'.format(self.image_size)) |
| 1184 | o.write(' Hash Algorithm: {}\n'.format(self.hash_algorithm)) |
| 1185 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1186 | o.write(' Salt: {}\n'.format(str(self.salt).encode( |
| 1187 | 'hex'))) |
| 1188 | o.write(' Digest: {}\n'.format(str(self.digest).encode( |
| 1189 | 'hex'))) |
| 1190 | |
| 1191 | def encode(self): |
| 1192 | """Serializes the descriptor. |
| 1193 | |
| 1194 | Returns: |
| 1195 | A bytearray() with the descriptor data. |
| 1196 | """ |
| 1197 | encoded_name = self.partition_name.encode('utf-8') |
| 1198 | num_bytes_following = ( |
| 1199 | self.SIZE + len(encoded_name) + len(self.salt) + len(self.digest) - 16) |
| 1200 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1201 | padding_size = nbf_with_padding - num_bytes_following |
| 1202 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
| 1203 | self.image_size, self.hash_algorithm, len(encoded_name), |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1204 | len(self.salt), len(self.digest), self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1205 | padding = struct.pack(str(padding_size) + 'x') |
| 1206 | ret = desc + encoded_name + self.salt + self.digest + padding |
| 1207 | return bytearray(ret) |
| 1208 | |
| 1209 | |
| 1210 | class AvbKernelCmdlineDescriptor(AvbDescriptor): |
| 1211 | """A class for kernel command-line descriptors. |
| 1212 | |
| 1213 | See the |AvbKernelCmdlineDescriptor| C struct for more information. |
| 1214 | |
| 1215 | Attributes: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1216 | flags: Flags. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1217 | kernel_cmdline: The kernel command-line. |
| 1218 | """ |
| 1219 | |
| 1220 | TAG = 3 |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1221 | SIZE = 24 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1222 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1223 | 'L' # flags |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1224 | 'L') # cmdline length (bytes) |
| 1225 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1226 | FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED = (1 << 0) |
| 1227 | FLAGS_USE_ONLY_IF_HASHTREE_DISABLED = (1 << 1) |
| 1228 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1229 | def __init__(self, data=None): |
| 1230 | """Initializes a new kernel cmdline descriptor. |
| 1231 | |
| 1232 | Arguments: |
| 1233 | data: If not None, must be a bytearray of size |SIZE|. |
| 1234 | |
| 1235 | Raises: |
| 1236 | LookupError: If the given descriptor is malformed. |
| 1237 | """ |
| 1238 | AvbDescriptor.__init__(self, None) |
| 1239 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1240 | |
| 1241 | if data: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1242 | (tag, num_bytes_following, self.flags, kernel_cmdline_length) = ( |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1243 | struct.unpack(self.FORMAT_STRING, data[0:self.SIZE])) |
| 1244 | expected_size = round_to_multiple(self.SIZE - 16 + kernel_cmdline_length, |
| 1245 | 8) |
| 1246 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1247 | raise LookupError('Given data does not look like a kernel cmdline ' |
| 1248 | 'descriptor.') |
| 1249 | # Nuke NUL-bytes at the end. |
| 1250 | self.kernel_cmdline = str(data[self.SIZE:(self.SIZE + |
| 1251 | kernel_cmdline_length)]) |
| 1252 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1253 | self.kernel_cmdline.decode('utf-8') |
| 1254 | else: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1255 | self.flags = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1256 | self.kernel_cmdline = '' |
| 1257 | |
| 1258 | def print_desc(self, o): |
| 1259 | """Print the descriptor. |
| 1260 | |
| 1261 | Arguments: |
| 1262 | o: The object to write the output to. |
| 1263 | """ |
| 1264 | o.write(' Kernel Cmdline descriptor:\n') |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1265 | o.write(' Flags: {}\n'.format(self.flags)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1266 | o.write(' Kernel Cmdline: {}\n'.format(repr( |
| 1267 | self.kernel_cmdline))) |
| 1268 | |
| 1269 | def encode(self): |
| 1270 | """Serializes the descriptor. |
| 1271 | |
| 1272 | Returns: |
| 1273 | A bytearray() with the descriptor data. |
| 1274 | """ |
| 1275 | encoded_str = self.kernel_cmdline.encode('utf-8') |
| 1276 | num_bytes_following = (self.SIZE + len(encoded_str) - 16) |
| 1277 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1278 | padding_size = nbf_with_padding - num_bytes_following |
| 1279 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1280 | self.flags, len(encoded_str)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1281 | padding = struct.pack(str(padding_size) + 'x') |
| 1282 | ret = desc + encoded_str + padding |
| 1283 | return bytearray(ret) |
| 1284 | |
| 1285 | |
| 1286 | class AvbChainPartitionDescriptor(AvbDescriptor): |
| 1287 | """A class for chained partition descriptors. |
| 1288 | |
| 1289 | See the |AvbChainPartitionDescriptor| C struct for more information. |
| 1290 | |
| 1291 | Attributes: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1292 | rollback_index_location: The rollback index location to use. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1293 | partition_name: Partition name. |
| 1294 | public_key: Bytes for the public key. |
| 1295 | """ |
| 1296 | |
| 1297 | TAG = 4 |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1298 | RESERVED = 64 |
| 1299 | SIZE = 28 + RESERVED |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1300 | FORMAT_STRING = ('!QQ' # tag, num_bytes_following (descriptor header) |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1301 | 'L' # rollback_index_location |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1302 | 'L' # partition_name_size (bytes) |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1303 | 'L' + # public_key_size (bytes) |
| 1304 | str(RESERVED) + 's') # reserved |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1305 | |
| 1306 | def __init__(self, data=None): |
| 1307 | """Initializes a new chain partition descriptor. |
| 1308 | |
| 1309 | Arguments: |
| 1310 | data: If not None, must be a bytearray of size |SIZE|. |
| 1311 | |
| 1312 | Raises: |
| 1313 | LookupError: If the given descriptor is malformed. |
| 1314 | """ |
| 1315 | AvbDescriptor.__init__(self, None) |
| 1316 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1317 | |
| 1318 | if data: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1319 | (tag, num_bytes_following, self.rollback_index_location, |
| 1320 | partition_name_len, |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1321 | public_key_len, _) = struct.unpack(self.FORMAT_STRING, data[0:self.SIZE]) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1322 | expected_size = round_to_multiple( |
| 1323 | self.SIZE - 16 + partition_name_len + public_key_len, 8) |
| 1324 | if tag != self.TAG or num_bytes_following != expected_size: |
| 1325 | raise LookupError('Given data does not look like a chain partition ' |
| 1326 | 'descriptor.') |
| 1327 | o = 0 |
| 1328 | self.partition_name = str(data[(self.SIZE + o):(self.SIZE + o + |
| 1329 | partition_name_len)]) |
| 1330 | # Validate UTF-8 - decode() raises UnicodeDecodeError if not valid UTF-8. |
| 1331 | self.partition_name.decode('utf-8') |
| 1332 | o += partition_name_len |
| 1333 | self.public_key = data[(self.SIZE + o):(self.SIZE + o + public_key_len)] |
| 1334 | |
| 1335 | else: |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1336 | self.rollback_index_location = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1337 | self.partition_name = '' |
| 1338 | self.public_key = bytearray() |
| 1339 | |
| 1340 | def print_desc(self, o): |
| 1341 | """Print the descriptor. |
| 1342 | |
| 1343 | Arguments: |
| 1344 | o: The object to write the output to. |
| 1345 | """ |
| 1346 | o.write(' Chain Partition descriptor:\n') |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1347 | o.write(' Partition Name: {}\n'.format(self.partition_name)) |
| 1348 | o.write(' Rollback Index Location: {}\n'.format( |
| 1349 | self.rollback_index_location)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1350 | # Just show the SHA1 of the key, for size reasons. |
| 1351 | hexdig = hashlib.sha1(self.public_key).hexdigest() |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1352 | o.write(' Public key (sha1): {}\n'.format(hexdig)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1353 | |
| 1354 | def encode(self): |
| 1355 | """Serializes the descriptor. |
| 1356 | |
| 1357 | Returns: |
| 1358 | A bytearray() with the descriptor data. |
| 1359 | """ |
| 1360 | encoded_name = self.partition_name.encode('utf-8') |
| 1361 | num_bytes_following = ( |
| 1362 | self.SIZE + len(encoded_name) + len(self.public_key) - 16) |
| 1363 | nbf_with_padding = round_to_multiple(num_bytes_following, 8) |
| 1364 | padding_size = nbf_with_padding - num_bytes_following |
| 1365 | desc = struct.pack(self.FORMAT_STRING, self.TAG, nbf_with_padding, |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1366 | self.rollback_index_location, len(encoded_name), |
David Zeuthen | 5cb2db9 | 2016-10-27 15:14:14 -0400 | [diff] [blame] | 1367 | len(self.public_key), self.RESERVED*'\0') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1368 | padding = struct.pack(str(padding_size) + 'x') |
| 1369 | ret = desc + encoded_name + self.public_key + padding |
| 1370 | return bytearray(ret) |
| 1371 | |
| 1372 | |
| 1373 | DESCRIPTOR_CLASSES = [ |
| 1374 | AvbPropertyDescriptor, AvbHashtreeDescriptor, AvbHashDescriptor, |
| 1375 | AvbKernelCmdlineDescriptor, AvbChainPartitionDescriptor |
| 1376 | ] |
| 1377 | |
| 1378 | |
| 1379 | def parse_descriptors(data): |
| 1380 | """Parses a blob of data into descriptors. |
| 1381 | |
| 1382 | Arguments: |
| 1383 | data: A bytearray() with encoded descriptors. |
| 1384 | |
| 1385 | Returns: |
| 1386 | A list of instances of objects derived from AvbDescriptor. For |
| 1387 | unknown descriptors, the class AvbDescriptor is used. |
| 1388 | """ |
| 1389 | o = 0 |
| 1390 | ret = [] |
| 1391 | while o < len(data): |
| 1392 | tag, nb_following = struct.unpack('!2Q', data[o:o + 16]) |
| 1393 | if tag < len(DESCRIPTOR_CLASSES): |
| 1394 | c = DESCRIPTOR_CLASSES[tag] |
| 1395 | else: |
| 1396 | c = AvbDescriptor |
| 1397 | ret.append(c(bytearray(data[o:o + 16 + nb_following]))) |
| 1398 | o += 16 + nb_following |
| 1399 | return ret |
| 1400 | |
| 1401 | |
| 1402 | class AvbFooter(object): |
| 1403 | """A class for parsing and writing footers. |
| 1404 | |
| 1405 | Footers are stored at the end of partitions and point to where the |
| 1406 | AvbVBMeta blob is located. They also contain the original size of |
| 1407 | the image before AVB information was added. |
| 1408 | |
| 1409 | Attributes: |
| 1410 | magic: Magic for identifying the footer, see |MAGIC|. |
| 1411 | version_major: The major version of avbtool that wrote the footer. |
| 1412 | version_minor: The minor version of avbtool that wrote the footer. |
| 1413 | original_image_size: Original image size. |
| 1414 | vbmeta_offset: Offset of where the AvbVBMeta blob is stored. |
| 1415 | vbmeta_size: Size of the AvbVBMeta blob. |
| 1416 | """ |
| 1417 | |
| 1418 | MAGIC = 'AVBf' |
| 1419 | SIZE = 64 |
| 1420 | RESERVED = 28 |
| 1421 | FORMAT_STRING = ('!4s2L' # magic, 2 x version. |
| 1422 | 'Q' # Original image size. |
| 1423 | 'Q' # Offset of VBMeta blob. |
| 1424 | 'Q' + # Size of VBMeta blob. |
| 1425 | str(RESERVED) + 'x') # padding for reserved bytes |
| 1426 | |
| 1427 | def __init__(self, data=None): |
| 1428 | """Initializes a new footer object. |
| 1429 | |
| 1430 | Arguments: |
| 1431 | data: If not None, must be a bytearray of size 4096. |
| 1432 | |
| 1433 | Raises: |
| 1434 | LookupError: If the given footer is malformed. |
| 1435 | struct.error: If the given data has no footer. |
| 1436 | """ |
| 1437 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1438 | |
| 1439 | if data: |
| 1440 | (self.magic, self.version_major, self.version_minor, |
| 1441 | self.original_image_size, self.vbmeta_offset, |
| 1442 | self.vbmeta_size) = struct.unpack(self.FORMAT_STRING, data) |
| 1443 | if self.magic != self.MAGIC: |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1444 | raise LookupError('Given data does not look like a AVB footer.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1445 | else: |
| 1446 | self.magic = self.MAGIC |
| 1447 | self.version_major = AVB_VERSION_MAJOR |
| 1448 | self.version_minor = AVB_VERSION_MINOR |
| 1449 | self.original_image_size = 0 |
| 1450 | self.vbmeta_offset = 0 |
| 1451 | self.vbmeta_size = 0 |
| 1452 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1453 | def encode(self): |
| 1454 | """Gets a string representing the binary encoding of the footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1455 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1456 | Returns: |
| 1457 | A bytearray() with a binary representation of the footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1458 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1459 | return struct.pack(self.FORMAT_STRING, self.magic, self.version_major, |
| 1460 | self.version_minor, self.original_image_size, |
| 1461 | self.vbmeta_offset, self.vbmeta_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1462 | |
| 1463 | |
| 1464 | class AvbVBMetaHeader(object): |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1465 | """A class for parsing and writing AVB vbmeta images. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1466 | |
| 1467 | Attributes: |
| 1468 | The attributes correspond to the |AvbVBMetaHeader| struct |
| 1469 | defined in avb_vbmeta_header.h. |
| 1470 | """ |
| 1471 | |
| 1472 | SIZE = 256 |
| 1473 | |
| 1474 | # Keep in sync with |reserved| field of |AvbVBMetaImageHeader|. |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1475 | RESERVED = 132 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1476 | |
| 1477 | # Keep in sync with |AvbVBMetaImageHeader|. |
| 1478 | FORMAT_STRING = ('!4s2L' # magic, 2 x version |
| 1479 | '2Q' # 2 x block size |
| 1480 | 'L' # algorithm type |
| 1481 | '2Q' # offset, size (hash) |
| 1482 | '2Q' # offset, size (signature) |
| 1483 | '2Q' # offset, size (public key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1484 | '2Q' # offset, size (public key metadata) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1485 | '2Q' # offset, size (descriptors) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1486 | 'Q' # rollback_index |
| 1487 | 'L' + # flags |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1488 | str(RESERVED) + 'x') # padding for reserved bytes |
| 1489 | |
| 1490 | def __init__(self, data=None): |
| 1491 | """Initializes a new header object. |
| 1492 | |
| 1493 | Arguments: |
| 1494 | data: If not None, must be a bytearray of size 8192. |
| 1495 | |
| 1496 | Raises: |
| 1497 | Exception: If the given data is malformed. |
| 1498 | """ |
| 1499 | assert struct.calcsize(self.FORMAT_STRING) == self.SIZE |
| 1500 | |
| 1501 | if data: |
| 1502 | (self.magic, self.header_version_major, self.header_version_minor, |
| 1503 | self.authentication_data_block_size, self.auxiliary_data_block_size, |
| 1504 | self.algorithm_type, self.hash_offset, self.hash_size, |
| 1505 | self.signature_offset, self.signature_size, self.public_key_offset, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1506 | self.public_key_size, self.public_key_metadata_offset, |
| 1507 | self.public_key_metadata_size, self.descriptors_offset, |
| 1508 | self.descriptors_size, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1509 | self.rollback_index, |
| 1510 | self.flags) = struct.unpack(self.FORMAT_STRING, data) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1511 | # Nuke NUL-bytes at the end of the string. |
| 1512 | if self.magic != 'AVB0': |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1513 | raise AvbError('Given image does not look like a vbmeta image.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1514 | else: |
| 1515 | self.magic = 'AVB0' |
| 1516 | self.header_version_major = AVB_VERSION_MAJOR |
| 1517 | self.header_version_minor = AVB_VERSION_MINOR |
| 1518 | self.authentication_data_block_size = 0 |
| 1519 | self.auxiliary_data_block_size = 0 |
| 1520 | self.algorithm_type = 0 |
| 1521 | self.hash_offset = 0 |
| 1522 | self.hash_size = 0 |
| 1523 | self.signature_offset = 0 |
| 1524 | self.signature_size = 0 |
| 1525 | self.public_key_offset = 0 |
| 1526 | self.public_key_size = 0 |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1527 | self.public_key_metadata_offset = 0 |
| 1528 | self.public_key_metadata_size = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1529 | self.descriptors_offset = 0 |
| 1530 | self.descriptors_size = 0 |
| 1531 | self.rollback_index = 0 |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1532 | self.flags = 0 |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1533 | |
| 1534 | def save(self, output): |
| 1535 | """Serializes the header (256 bytes) to disk. |
| 1536 | |
| 1537 | Arguments: |
| 1538 | output: The object to write the output to. |
| 1539 | """ |
| 1540 | output.write(struct.pack( |
| 1541 | self.FORMAT_STRING, self.magic, self.header_version_major, |
| 1542 | self.header_version_minor, self.authentication_data_block_size, |
| 1543 | self.auxiliary_data_block_size, self.algorithm_type, self.hash_offset, |
| 1544 | self.hash_size, self.signature_offset, self.signature_size, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1545 | self.public_key_offset, self.public_key_size, |
| 1546 | self.public_key_metadata_offset, self.public_key_metadata_size, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1547 | self.descriptors_offset, self.descriptors_size, self.rollback_index, |
| 1548 | self.flags)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1549 | |
| 1550 | def encode(self): |
| 1551 | """Serializes the header (256) to a bytearray(). |
| 1552 | |
| 1553 | Returns: |
| 1554 | A bytearray() with the encoded header. |
| 1555 | """ |
| 1556 | return struct.pack(self.FORMAT_STRING, self.magic, |
| 1557 | self.header_version_major, self.header_version_minor, |
| 1558 | self.authentication_data_block_size, |
| 1559 | self.auxiliary_data_block_size, self.algorithm_type, |
| 1560 | self.hash_offset, self.hash_size, self.signature_offset, |
| 1561 | self.signature_size, self.public_key_offset, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1562 | self.public_key_size, self.public_key_metadata_offset, |
| 1563 | self.public_key_metadata_size, self.descriptors_offset, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1564 | self.descriptors_size, self.rollback_index, self.flags) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1565 | |
| 1566 | |
| 1567 | class Avb(object): |
| 1568 | """Business logic for avbtool command-line tool.""" |
| 1569 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1570 | # Keep in sync with avb_ab_flow.h. |
| 1571 | AB_FORMAT_NO_CRC = '!4sBB2xBBBxBBBx12x' |
| 1572 | AB_MAGIC = '\0AB0' |
| 1573 | AB_MAJOR_VERSION = 1 |
| 1574 | AB_MINOR_VERSION = 0 |
| 1575 | AB_MISC_METADATA_OFFSET = 2048 |
| 1576 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 1577 | # Constants for maximum metadata size. These are used to give |
| 1578 | # meaningful errors if the value passed in via --partition_size is |
| 1579 | # too small and when --calc_max_image_size is used. We use |
| 1580 | # conservative figures. |
| 1581 | MAX_VBMETA_SIZE = 64 * 1024 |
| 1582 | MAX_FOOTER_SIZE = 4096 |
| 1583 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1584 | def erase_footer(self, image_filename, keep_hashtree): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1585 | """Implements the 'erase_footer' command. |
| 1586 | |
| 1587 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1588 | image_filename: File to erase a footer from. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1589 | keep_hashtree: If True, keep the hashtree around. |
| 1590 | |
| 1591 | Raises: |
| 1592 | AvbError: If there's no footer in the image. |
| 1593 | """ |
| 1594 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1595 | image = ImageHandler(image_filename) |
| 1596 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1597 | (footer, _, descriptors, _) = self._parse_image(image) |
| 1598 | |
| 1599 | if not footer: |
| 1600 | raise AvbError('Given image does not have a footer.') |
| 1601 | |
| 1602 | new_image_size = None |
| 1603 | if not keep_hashtree: |
| 1604 | new_image_size = footer.original_image_size |
| 1605 | else: |
| 1606 | # If requested to keep the hashtree, search for a hashtree |
| 1607 | # descriptor to figure out the location and size of the hashtree. |
| 1608 | for desc in descriptors: |
| 1609 | if isinstance(desc, AvbHashtreeDescriptor): |
| 1610 | # The hashtree is always just following the main data so the |
| 1611 | # new size is easily derived. |
| 1612 | new_image_size = desc.tree_offset + desc.tree_size |
| 1613 | break |
| 1614 | if not new_image_size: |
| 1615 | raise AvbError('Requested to keep hashtree but no hashtree ' |
| 1616 | 'descriptor was found.') |
| 1617 | |
| 1618 | # And cut... |
| 1619 | image.truncate(new_image_size) |
| 1620 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 1621 | def set_ab_metadata(self, misc_image, slot_data): |
| 1622 | """Implements the 'set_ab_metadata' command. |
| 1623 | |
| 1624 | The |slot_data| argument must be of the form 'A_priority:A_tries_remaining: |
| 1625 | A_successful_boot:B_priority:B_tries_remaining:B_successful_boot'. |
| 1626 | |
| 1627 | Arguments: |
| 1628 | misc_image: The misc image to write to. |
| 1629 | slot_data: Slot data as a string |
| 1630 | |
| 1631 | Raises: |
| 1632 | AvbError: If slot data is malformed. |
| 1633 | """ |
| 1634 | tokens = slot_data.split(':') |
| 1635 | if len(tokens) != 6: |
| 1636 | raise AvbError('Malformed slot data "{}".'.format(slot_data)) |
| 1637 | a_priority = int(tokens[0]) |
| 1638 | a_tries_remaining = int(tokens[1]) |
| 1639 | a_success = True if int(tokens[2]) != 0 else False |
| 1640 | b_priority = int(tokens[3]) |
| 1641 | b_tries_remaining = int(tokens[4]) |
| 1642 | b_success = True if int(tokens[5]) != 0 else False |
| 1643 | |
| 1644 | ab_data_no_crc = struct.pack(self.AB_FORMAT_NO_CRC, |
| 1645 | self.AB_MAGIC, |
| 1646 | self.AB_MAJOR_VERSION, self.AB_MINOR_VERSION, |
| 1647 | a_priority, a_tries_remaining, a_success, |
| 1648 | b_priority, b_tries_remaining, b_success) |
| 1649 | # Force CRC to be unsigned, see https://bugs.python.org/issue4903 for why. |
| 1650 | crc_value = binascii.crc32(ab_data_no_crc) & 0xffffffff |
| 1651 | ab_data = ab_data_no_crc + struct.pack('!I', crc_value) |
| 1652 | misc_image.seek(self.AB_MISC_METADATA_OFFSET) |
| 1653 | misc_image.write(ab_data) |
| 1654 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1655 | def info_image(self, image_filename, output): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1656 | """Implements the 'info_image' command. |
| 1657 | |
| 1658 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1659 | image_filename: Image file to get information from (file object). |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1660 | output: Output file to write human-readable information to (file object). |
| 1661 | """ |
| 1662 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1663 | image = ImageHandler(image_filename) |
| 1664 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1665 | o = output |
| 1666 | |
| 1667 | (footer, header, descriptors, image_size) = self._parse_image(image) |
| 1668 | |
| 1669 | if footer: |
| 1670 | o.write('Footer version: {}.{}\n'.format(footer.version_major, |
| 1671 | footer.version_minor)) |
| 1672 | o.write('Image size: {} bytes\n'.format(image_size)) |
| 1673 | o.write('Original image size: {} bytes\n'.format( |
| 1674 | footer.original_image_size)) |
| 1675 | o.write('VBMeta offset: {}\n'.format(footer.vbmeta_offset)) |
| 1676 | o.write('VBMeta size: {} bytes\n'.format(footer.vbmeta_size)) |
| 1677 | o.write('--\n') |
| 1678 | |
| 1679 | (alg_name, _) = lookup_algorithm_by_type(header.algorithm_type) |
| 1680 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1681 | o.write('VBMeta image version: {}.{}{}\n'.format( |
| 1682 | header.header_version_major, header.header_version_minor, |
| 1683 | ' (Sparse)' if image.is_sparse else '')) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1684 | o.write('Header Block: {} bytes\n'.format(AvbVBMetaHeader.SIZE)) |
| 1685 | o.write('Authentication Block: {} bytes\n'.format( |
| 1686 | header.authentication_data_block_size)) |
| 1687 | o.write('Auxiliary Block: {} bytes\n'.format( |
| 1688 | header.auxiliary_data_block_size)) |
| 1689 | o.write('Algorithm: {}\n'.format(alg_name)) |
| 1690 | o.write('Rollback Index: {}\n'.format(header.rollback_index)) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1691 | o.write('Flags: {}\n'.format(header.flags)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1692 | |
| 1693 | # Print descriptors. |
| 1694 | num_printed = 0 |
| 1695 | o.write('Descriptors:\n') |
| 1696 | for desc in descriptors: |
| 1697 | desc.print_desc(o) |
| 1698 | num_printed += 1 |
| 1699 | if num_printed == 0: |
| 1700 | o.write(' (none)\n') |
| 1701 | |
| 1702 | def _parse_image(self, image): |
| 1703 | """Gets information about an image. |
| 1704 | |
| 1705 | The image can either be a vbmeta or an image with a footer. |
| 1706 | |
| 1707 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1708 | image: An ImageHandler (vbmeta or footer) with a hashtree descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1709 | |
| 1710 | Returns: |
| 1711 | A tuple where the first argument is a AvbFooter (None if there |
| 1712 | is no footer on the image), the second argument is a |
| 1713 | AvbVBMetaHeader, the third argument is a list of |
| 1714 | AvbDescriptor-derived instances, and the fourth argument is the |
| 1715 | size of |image|. |
| 1716 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1717 | assert isinstance(image, ImageHandler) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1718 | footer = None |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 1719 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1720 | try: |
| 1721 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 1722 | except (LookupError, struct.error): |
| 1723 | # Nope, just seek back to the start. |
| 1724 | image.seek(0) |
| 1725 | |
| 1726 | vbmeta_offset = 0 |
| 1727 | if footer: |
| 1728 | vbmeta_offset = footer.vbmeta_offset |
| 1729 | |
| 1730 | image.seek(vbmeta_offset) |
| 1731 | h = AvbVBMetaHeader(image.read(AvbVBMetaHeader.SIZE)) |
| 1732 | |
| 1733 | auth_block_offset = vbmeta_offset + AvbVBMetaHeader.SIZE |
| 1734 | aux_block_offset = auth_block_offset + h.authentication_data_block_size |
| 1735 | desc_start_offset = aux_block_offset + h.descriptors_offset |
| 1736 | image.seek(desc_start_offset) |
| 1737 | descriptors = parse_descriptors(image.read(h.descriptors_size)) |
| 1738 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 1739 | return footer, h, descriptors, image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1740 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1741 | def _get_cmdline_descriptors_for_dm_verity(self, image): |
| 1742 | """Generate kernel cmdline descriptors for dm-verity. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1743 | |
| 1744 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1745 | image: An ImageHandler (vbmeta or footer) with a hashtree descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1746 | |
| 1747 | Returns: |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1748 | A list with two AvbKernelCmdlineDescriptor with dm-verity kernel cmdline |
| 1749 | instructions. There is one for when hashtree is not disabled and one for |
| 1750 | when it is. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1751 | |
| 1752 | Raises: |
| 1753 | AvbError: If |image| doesn't have a hashtree descriptor. |
| 1754 | |
| 1755 | """ |
| 1756 | |
| 1757 | (_, _, descriptors, _) = self._parse_image(image) |
| 1758 | |
| 1759 | ht = None |
| 1760 | for desc in descriptors: |
| 1761 | if isinstance(desc, AvbHashtreeDescriptor): |
| 1762 | ht = desc |
| 1763 | break |
| 1764 | |
| 1765 | if not ht: |
| 1766 | raise AvbError('No hashtree descriptor in given image') |
| 1767 | |
| 1768 | c = 'dm="1 vroot none ro 1,' |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 1769 | c += '0' # start |
| 1770 | c += ' {}'.format((ht.image_size / 512)) # size (# sectors) |
| 1771 | c += ' verity {}'.format(ht.dm_verity_version) # type and version |
| 1772 | c += ' PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' # data_dev |
| 1773 | c += ' PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' # hash_dev |
| 1774 | c += ' {}'.format(ht.data_block_size) # data_block |
| 1775 | c += ' {}'.format(ht.hash_block_size) # hash_block |
| 1776 | c += ' {}'.format(ht.image_size / ht.data_block_size) # #blocks |
| 1777 | c += ' {}'.format(ht.image_size / ht.data_block_size) # hash_offset |
| 1778 | c += ' {}'.format(ht.hash_algorithm) # hash_alg |
| 1779 | c += ' {}'.format(str(ht.root_digest).encode('hex')) # root_digest |
| 1780 | c += ' {}'.format(str(ht.salt).encode('hex')) # salt |
| 1781 | if ht.fec_num_roots > 0: |
| 1782 | c += ' 9' # number of optional args |
| 1783 | c += ' ignore_zero_blocks' |
| 1784 | c += ' use_fec_from_device PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' |
| 1785 | c += ' fec_roots {}'.format(ht.fec_num_roots) |
| 1786 | # Note that fec_blocks is the size that FEC covers, *not* the |
| 1787 | # size of the FEC data. Since we use FEC for everything up until |
| 1788 | # the FEC data, it's the same as the offset. |
| 1789 | c += ' fec_blocks {}'.format(ht.fec_offset/ht.data_block_size) |
| 1790 | c += ' fec_start {}'.format(ht.fec_offset/ht.data_block_size) |
| 1791 | else: |
| 1792 | c += ' 1' # number of optional args |
| 1793 | c += ' ignore_zero_blocks' |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1794 | c += '" root=0xfd00' |
David Zeuthen | bc8f647 | 2016-11-21 14:59:15 -0500 | [diff] [blame] | 1795 | c += ' androidboot.vbmeta.device=PARTUUID=$(ANDROID_VBMETA_PARTUUID)' |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1796 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1797 | # Now that we have the command-line, generate the descriptor. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1798 | desc = AvbKernelCmdlineDescriptor() |
| 1799 | desc.kernel_cmdline = c |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1800 | desc.flags = ( |
| 1801 | AvbKernelCmdlineDescriptor.FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) |
| 1802 | |
| 1803 | # The descriptor for when hashtree verification is disabled is a lot |
| 1804 | # simpler - we just set the root to the partition. |
| 1805 | desc_no_ht = AvbKernelCmdlineDescriptor() |
| 1806 | desc_no_ht.kernel_cmdline = 'root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)' |
| 1807 | desc_no_ht.flags = ( |
| 1808 | AvbKernelCmdlineDescriptor.FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) |
| 1809 | |
| 1810 | return [desc, desc_no_ht] |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1811 | |
| 1812 | def make_vbmeta_image(self, output, chain_partitions, algorithm_name, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1813 | key_path, public_key_metadata_path, rollback_index, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1814 | flags, props, props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1815 | generate_dm_verity_cmdline_from_hashtree, |
| 1816 | include_descriptors_from_image): |
| 1817 | """Implements the 'make_vbmeta_image' command. |
| 1818 | |
| 1819 | Arguments: |
| 1820 | output: File to write the image to. |
| 1821 | chain_partitions: List of partitions to chain. |
| 1822 | algorithm_name: Name of algorithm to use. |
| 1823 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1824 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1825 | rollback_index: The rollback index to use. |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1826 | flags: Flags value to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1827 | props: Properties to insert (list of strings of the form 'key:value'). |
| 1828 | props_from_file: Properties to insert (list of strings 'key:<path>'). |
| 1829 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
| 1830 | generate_dm_verity_cmdline_from_hashtree: None or file to generate from. |
| 1831 | include_descriptors_from_image: List of file objects with descriptors. |
| 1832 | |
| 1833 | Raises: |
| 1834 | AvbError: If a chained partition is malformed. |
| 1835 | """ |
| 1836 | |
| 1837 | descriptors = [] |
| 1838 | |
| 1839 | # Insert chained partition descriptors. |
| 1840 | if chain_partitions: |
| 1841 | for cp in chain_partitions: |
| 1842 | cp_tokens = cp.split(':') |
| 1843 | if len(cp_tokens) != 3: |
| 1844 | raise AvbError('Malformed chained partition "{}".'.format(cp)) |
| 1845 | desc = AvbChainPartitionDescriptor() |
| 1846 | desc.partition_name = cp_tokens[0] |
David Zeuthen | 40ee1da | 2016-11-23 15:14:49 -0500 | [diff] [blame] | 1847 | desc.rollback_index_location = int(cp_tokens[1]) |
| 1848 | if desc.rollback_index_location < 1: |
| 1849 | raise AvbError('Rollback index location must be 1 or larger.') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1850 | file_path = cp_tokens[2] |
| 1851 | desc.public_key = open(file_path, 'rb').read() |
| 1852 | descriptors.append(desc) |
| 1853 | |
| 1854 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1855 | algorithm_name, key_path, public_key_metadata_path, descriptors, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1856 | rollback_index, flags, props, props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1857 | generate_dm_verity_cmdline_from_hashtree, |
| 1858 | include_descriptors_from_image) |
| 1859 | |
| 1860 | # Write entire vbmeta blob (header, authentication, auxiliary). |
| 1861 | output.seek(0) |
| 1862 | output.write(vbmeta_blob) |
| 1863 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1864 | def _generate_vbmeta_blob(self, algorithm_name, key_path, |
| 1865 | public_key_metadata_path, descriptors, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1866 | rollback_index, flags, props, props_from_file, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1867 | kernel_cmdlines, |
| 1868 | generate_dm_verity_cmdline_from_hashtree, |
| 1869 | include_descriptors_from_image): |
| 1870 | """Generates a VBMeta blob. |
| 1871 | |
| 1872 | This blob contains the header (struct AvbVBMetaHeader), the |
| 1873 | authentication data block (which contains the hash and signature |
| 1874 | for the header and auxiliary block), and the auxiliary block |
| 1875 | (which contains descriptors, the public key used, and other data). |
| 1876 | |
| 1877 | The |key| parameter can |None| only if the |algorithm_name| is |
| 1878 | 'NONE'. |
| 1879 | |
| 1880 | Arguments: |
| 1881 | algorithm_name: The algorithm name as per the ALGORITHMS dict. |
| 1882 | 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] | 1883 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1884 | descriptors: A list of descriptors to insert or None. |
| 1885 | rollback_index: The rollback index to use. |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1886 | flags: Flags to use in the image. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1887 | props: Properties to insert (List of strings of the form 'key:value'). |
| 1888 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 1889 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
| 1890 | generate_dm_verity_cmdline_from_hashtree: None or file to generate |
| 1891 | dm-verity kernel cmdline from. |
| 1892 | include_descriptors_from_image: List of file objects for which |
| 1893 | to insert descriptors from. |
| 1894 | |
| 1895 | Returns: |
| 1896 | A bytearray() with the VBMeta blob. |
| 1897 | |
| 1898 | Raises: |
| 1899 | Exception: If the |algorithm_name| is not found, if no key has |
| 1900 | been given and the given algorithm requires one, or the key is |
| 1901 | of the wrong size. |
| 1902 | |
| 1903 | """ |
| 1904 | try: |
| 1905 | alg = ALGORITHMS[algorithm_name] |
| 1906 | except KeyError: |
| 1907 | raise AvbError('Unknown algorithm with name {}'.format(algorithm_name)) |
| 1908 | |
| 1909 | # Descriptors. |
| 1910 | encoded_descriptors = bytearray() |
| 1911 | if descriptors: |
| 1912 | for desc in descriptors: |
| 1913 | encoded_descriptors.extend(desc.encode()) |
| 1914 | |
| 1915 | # Add properties. |
| 1916 | if props: |
| 1917 | for prop in props: |
| 1918 | idx = prop.find(':') |
| 1919 | if idx == -1: |
| 1920 | raise AvbError('Malformed property "{}".'.format(prop)) |
| 1921 | desc = AvbPropertyDescriptor() |
| 1922 | desc.key = prop[0:idx] |
| 1923 | desc.value = prop[(idx + 1):] |
| 1924 | encoded_descriptors.extend(desc.encode()) |
| 1925 | if props_from_file: |
| 1926 | for prop in props_from_file: |
| 1927 | idx = prop.find(':') |
| 1928 | if idx == -1: |
| 1929 | raise AvbError('Malformed property "{}".'.format(prop)) |
| 1930 | desc = AvbPropertyDescriptor() |
| 1931 | desc.key = prop[0:idx] |
| 1932 | desc.value = prop[(idx + 1):] |
| 1933 | file_path = prop[(idx + 1):] |
| 1934 | desc.value = open(file_path, 'rb').read() |
| 1935 | encoded_descriptors.extend(desc.encode()) |
| 1936 | |
| 1937 | # Add AvbKernelCmdline descriptor for dm-verity, if requested. |
| 1938 | if generate_dm_verity_cmdline_from_hashtree: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1939 | image_handler = ImageHandler( |
| 1940 | generate_dm_verity_cmdline_from_hashtree.name) |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 1941 | cmdline_desc = self._get_cmdline_descriptors_for_dm_verity(image_handler) |
| 1942 | encoded_descriptors.extend(cmdline_desc[0].encode()) |
| 1943 | encoded_descriptors.extend(cmdline_desc[1].encode()) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1944 | |
| 1945 | # Add kernel command-lines. |
| 1946 | if kernel_cmdlines: |
| 1947 | for i in kernel_cmdlines: |
| 1948 | desc = AvbKernelCmdlineDescriptor() |
| 1949 | desc.kernel_cmdline = i |
| 1950 | encoded_descriptors.extend(desc.encode()) |
| 1951 | |
| 1952 | # Add descriptors from other images. |
| 1953 | if include_descriptors_from_image: |
| 1954 | for image in include_descriptors_from_image: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 1955 | image_handler = ImageHandler(image.name) |
| 1956 | (_, _, image_descriptors, _) = self._parse_image(image_handler) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1957 | for desc in image_descriptors: |
| 1958 | encoded_descriptors.extend(desc.encode()) |
| 1959 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1960 | # Load public key metadata blob, if requested. |
| 1961 | pkmd_blob = [] |
| 1962 | if public_key_metadata_path: |
| 1963 | with open(public_key_metadata_path) as f: |
| 1964 | pkmd_blob = f.read() |
| 1965 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1966 | key = None |
| 1967 | encoded_key = bytearray() |
| 1968 | if alg.public_key_num_bytes > 0: |
| 1969 | if not key_path: |
| 1970 | raise AvbError('Key is required for algorithm {}'.format( |
| 1971 | algorithm_name)) |
| 1972 | key = Crypto.PublicKey.RSA.importKey(open(key_path).read()) |
| 1973 | encoded_key = encode_rsa_key(key) |
| 1974 | if len(encoded_key) != alg.public_key_num_bytes: |
| 1975 | raise AvbError('Key is wrong size for algorithm {}'.format( |
| 1976 | algorithm_name)) |
| 1977 | |
| 1978 | h = AvbVBMetaHeader() |
| 1979 | |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1980 | # For the Auxiliary data block, descriptors are stored at offset 0, |
| 1981 | # followed by the public key, followed by the public key metadata blob. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1982 | h.auxiliary_data_block_size = round_to_multiple( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1983 | len(encoded_descriptors) + len(encoded_key) + len(pkmd_blob), 64) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1984 | h.descriptors_offset = 0 |
| 1985 | h.descriptors_size = len(encoded_descriptors) |
| 1986 | h.public_key_offset = h.descriptors_size |
| 1987 | h.public_key_size = len(encoded_key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 1988 | h.public_key_metadata_offset = h.public_key_offset + h.public_key_size |
| 1989 | h.public_key_metadata_size = len(pkmd_blob) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 1990 | |
| 1991 | # For the Authentication data block, the hash is first and then |
| 1992 | # the signature. |
| 1993 | h.authentication_data_block_size = round_to_multiple( |
| 1994 | alg.hash_num_bytes + alg.public_key_num_bytes, 64) |
| 1995 | h.algorithm_type = alg.algorithm_type |
| 1996 | h.hash_offset = 0 |
| 1997 | h.hash_size = alg.hash_num_bytes |
| 1998 | # Signature offset and size - it's stored right after the hash |
| 1999 | # (in Authentication data block). |
| 2000 | h.signature_offset = alg.hash_num_bytes |
| 2001 | h.signature_size = alg.signature_num_bytes |
| 2002 | |
| 2003 | h.rollback_index = rollback_index |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2004 | h.flags = flags |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2005 | |
| 2006 | # Generate Header data block. |
| 2007 | header_data_blob = h.encode() |
| 2008 | |
| 2009 | # Generate Auxiliary data block. |
| 2010 | aux_data_blob = bytearray() |
| 2011 | aux_data_blob.extend(encoded_descriptors) |
| 2012 | aux_data_blob.extend(encoded_key) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2013 | aux_data_blob.extend(pkmd_blob) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2014 | padding_bytes = h.auxiliary_data_block_size - len(aux_data_blob) |
| 2015 | aux_data_blob.extend('\0' * padding_bytes) |
| 2016 | |
| 2017 | # Calculate the hash. |
| 2018 | binary_hash = bytearray() |
| 2019 | binary_signature = bytearray() |
| 2020 | if algorithm_name != 'NONE': |
| 2021 | if algorithm_name[0:6] == 'SHA256': |
| 2022 | ha = hashlib.sha256() |
| 2023 | elif algorithm_name[0:6] == 'SHA512': |
| 2024 | ha = hashlib.sha512() |
| 2025 | else: |
| 2026 | raise AvbError('Unsupported algorithm {}.'.format(algorithm_name)) |
| 2027 | ha.update(header_data_blob) |
| 2028 | ha.update(aux_data_blob) |
| 2029 | binary_hash.extend(ha.digest()) |
| 2030 | |
| 2031 | # Calculate the signature. |
| 2032 | p = subprocess.Popen( |
| 2033 | ['openssl', 'rsautl', '-sign', '-inkey', key_path, '-raw'], |
| 2034 | stdin=subprocess.PIPE, |
| 2035 | stdout=subprocess.PIPE, |
| 2036 | stderr=subprocess.PIPE) |
| 2037 | padding_and_hash = str(bytearray(alg.padding)) + binary_hash |
| 2038 | (pout, perr) = p.communicate(padding_and_hash) |
| 2039 | retcode = p.wait() |
| 2040 | if retcode != 0: |
| 2041 | raise AvbError('Error signing: {}'.format(perr)) |
| 2042 | binary_signature.extend(pout) |
| 2043 | |
| 2044 | # Generate Authentication data block. |
| 2045 | auth_data_blob = bytearray() |
| 2046 | auth_data_blob.extend(binary_hash) |
| 2047 | auth_data_blob.extend(binary_signature) |
| 2048 | padding_bytes = h.authentication_data_block_size - len(auth_data_blob) |
| 2049 | auth_data_blob.extend('\0' * padding_bytes) |
| 2050 | |
| 2051 | return header_data_blob + auth_data_blob + aux_data_blob |
| 2052 | |
| 2053 | def extract_public_key(self, key_path, output): |
| 2054 | """Implements the 'extract_public_key' command. |
| 2055 | |
| 2056 | Arguments: |
| 2057 | key_path: The path to a RSA private key file. |
| 2058 | output: The file to write to. |
| 2059 | """ |
| 2060 | key = Crypto.PublicKey.RSA.importKey(open(key_path).read()) |
| 2061 | write_rsa_key(output, key) |
| 2062 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2063 | def add_hash_footer(self, image_filename, partition_size, partition_name, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2064 | hash_algorithm, salt, algorithm_name, key_path, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2065 | public_key_metadata_path, rollback_index, props, |
| 2066 | props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2067 | generate_dm_verity_cmdline_from_hashtree, |
| 2068 | include_descriptors_from_image): |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2069 | """Implementation of the add_hash_footer on unsparse images. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2070 | |
| 2071 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2072 | image_filename: File to add the footer to. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2073 | partition_size: Size of partition. |
| 2074 | partition_name: Name of partition (without A/B suffix). |
| 2075 | hash_algorithm: Hash algorithm to use. |
| 2076 | salt: Salt to use as a hexadecimal string or None to use /dev/urandom. |
| 2077 | algorithm_name: Name of algorithm to use. |
| 2078 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2079 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2080 | rollback_index: Rollback index. |
| 2081 | props: Properties to insert (List of strings of the form 'key:value'). |
| 2082 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 2083 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
| 2084 | generate_dm_verity_cmdline_from_hashtree: None or file to generate |
| 2085 | dm-verity kernel cmdline from. |
| 2086 | include_descriptors_from_image: List of file objects for which |
| 2087 | to insert descriptors from. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2088 | |
| 2089 | Raises: |
| 2090 | AvbError: If an argument is incorrect. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2091 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2092 | image = ImageHandler(image_filename) |
| 2093 | |
| 2094 | if partition_size % image.block_size != 0: |
| 2095 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 2096 | 'block size {}.'.format(partition_size, |
| 2097 | image.block_size)) |
| 2098 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2099 | # If there's already a footer, truncate the image to its original |
| 2100 | # size. This way 'avbtool add_hash_footer' is idempotent (modulo |
| 2101 | # salts). |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2102 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2103 | try: |
| 2104 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2105 | # Existing footer found. Just truncate. |
| 2106 | original_image_size = footer.original_image_size |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2107 | image.truncate(footer.original_image_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2108 | except (LookupError, struct.error): |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2109 | original_image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2110 | |
| 2111 | # If anything goes wrong from here-on, restore the image back to |
| 2112 | # its original size. |
| 2113 | try: |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2114 | # First, calculate the maximum image size such that an image |
| 2115 | # this size + metadata (footer + vbmeta struct) fits in |
| 2116 | # |partition_size|. |
| 2117 | max_metadata_size = self.MAX_VBMETA_SIZE + self.MAX_FOOTER_SIZE |
| 2118 | max_image_size = partition_size - max_metadata_size |
| 2119 | |
| 2120 | # If image size exceeds the maximum image size, fail. |
| 2121 | if image.image_size > max_image_size: |
| 2122 | raise AvbError('Image size of {} exceeds maximum image ' |
| 2123 | 'size of {} in order to fit in a partition ' |
| 2124 | 'size of {}.'.format(image.image_size, max_image_size, |
| 2125 | partition_size)) |
| 2126 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2127 | digest_size = len(hashlib.new(name=hash_algorithm).digest()) |
| 2128 | if salt: |
| 2129 | salt = salt.decode('hex') |
| 2130 | else: |
| 2131 | if salt is None: |
| 2132 | # If salt is not explicitly specified, choose a hash |
| 2133 | # that's the same size as the hash size. |
| 2134 | hash_size = digest_size |
| 2135 | salt = open('/dev/urandom').read(hash_size) |
| 2136 | else: |
| 2137 | salt = '' |
| 2138 | |
| 2139 | hasher = hashlib.new(name=hash_algorithm, string=salt) |
| 2140 | # TODO(zeuthen): might want to read this in chunks to avoid |
| 2141 | # memory pressure, then again, this is only supposed to be used |
| 2142 | # on kernel/initramfs partitions. Possible optimization. |
| 2143 | image.seek(0) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2144 | hasher.update(image.read(image.image_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2145 | digest = hasher.digest() |
| 2146 | |
| 2147 | h_desc = AvbHashDescriptor() |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2148 | h_desc.image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2149 | h_desc.hash_algorithm = hash_algorithm |
| 2150 | h_desc.partition_name = partition_name |
| 2151 | h_desc.salt = salt |
| 2152 | h_desc.digest = digest |
| 2153 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2154 | # Flags are only allowed on top-level vbmeta struct. |
| 2155 | flags = 0 |
| 2156 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2157 | # Generate the VBMeta footer. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2158 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2159 | algorithm_name, key_path, public_key_metadata_path, [h_desc], |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2160 | rollback_index, flags, props, props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2161 | generate_dm_verity_cmdline_from_hashtree, |
| 2162 | include_descriptors_from_image) |
| 2163 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2164 | # If the image isn't sparse, its size might not be a multiple of |
| 2165 | # 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] | 2166 | if image.image_size % image.block_size != 0: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2167 | assert not image.is_sparse |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2168 | padding_needed = image.block_size - (image.image_size%image.block_size) |
| 2169 | image.truncate(image.image_size + padding_needed) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2170 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2171 | # The append_raw() method requires content with size being a |
| 2172 | # multiple of |block_size| so add padding as needed. Also record |
| 2173 | # where this is written to since we'll need to put that in the |
| 2174 | # footer. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2175 | vbmeta_offset = image.image_size |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2176 | padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) - |
| 2177 | len(vbmeta_blob)) |
| 2178 | vbmeta_blob_with_padding = vbmeta_blob + '\0'*padding_needed |
| 2179 | image.append_raw(vbmeta_blob_with_padding) |
| 2180 | vbmeta_end_offset = vbmeta_offset + len(vbmeta_blob_with_padding) |
| 2181 | |
| 2182 | # Now insert a DONT_CARE chunk with enough bytes such that the |
| 2183 | # final Footer block is at the end of partition_size.. |
| 2184 | image.append_dont_care(partition_size - vbmeta_end_offset - |
| 2185 | 1*image.block_size) |
| 2186 | |
| 2187 | # Generate the Footer that tells where the VBMeta footer |
| 2188 | # is. Also put enough padding in the front of the footer since |
| 2189 | # we'll write out an entire block. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2190 | footer = AvbFooter() |
| 2191 | footer.original_image_size = original_image_size |
| 2192 | footer.vbmeta_offset = vbmeta_offset |
| 2193 | footer.vbmeta_size = len(vbmeta_blob) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2194 | footer_blob = footer.encode() |
| 2195 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 2196 | footer_blob) |
| 2197 | image.append_raw(footer_blob_with_padding) |
| 2198 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2199 | except: |
| 2200 | # Truncate back to original size, then re-raise |
| 2201 | image.truncate(original_image_size) |
| 2202 | raise |
| 2203 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2204 | def add_hashtree_footer(self, image_filename, partition_size, partition_name, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2205 | generate_fec, fec_num_roots, hash_algorithm, |
| 2206 | block_size, salt, algorithm_name, key_path, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2207 | public_key_metadata_path, rollback_index, |
| 2208 | props, props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2209 | generate_dm_verity_cmdline_from_hashtree, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2210 | include_descriptors_from_image, |
| 2211 | calc_max_image_size): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2212 | """Implements the 'add_hashtree_footer' command. |
| 2213 | |
| 2214 | See https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for |
| 2215 | more information about dm-verity and these hashes. |
| 2216 | |
| 2217 | Arguments: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2218 | image_filename: File to add the footer to. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2219 | partition_size: Size of partition. |
| 2220 | partition_name: Name of partition (without A/B suffix). |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2221 | generate_fec: If True, generate FEC codes. |
| 2222 | fec_num_roots: Number of roots for FEC. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2223 | hash_algorithm: Hash algorithm to use. |
| 2224 | block_size: Block size to use. |
| 2225 | salt: Salt to use as a hexadecimal string or None to use /dev/urandom. |
| 2226 | algorithm_name: Name of algorithm to use. |
| 2227 | key_path: Path to key to use or None. |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2228 | public_key_metadata_path: Path to public key metadata or None. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2229 | rollback_index: Rollback index. |
| 2230 | props: Properties to insert (List of strings of the form 'key:value'). |
| 2231 | props_from_file: Properties to insert (List of strings 'key:<path>'). |
| 2232 | kernel_cmdlines: Kernel cmdlines to insert (list of strings). |
| 2233 | generate_dm_verity_cmdline_from_hashtree: None or file to generate |
| 2234 | dm-verity kernel cmdline from. |
| 2235 | include_descriptors_from_image: List of file objects for which |
| 2236 | to insert descriptors from. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2237 | calc_max_image_size: Don't store the hashtree or footer - instead |
| 2238 | calculate the maximum image size leaving enough room for hashtree |
| 2239 | and metadata with the given |partition_size|. |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2240 | |
| 2241 | Raises: |
| 2242 | AvbError: If an argument is incorrect. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2243 | """ |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2244 | digest_size = len(hashlib.new(name=hash_algorithm).digest()) |
| 2245 | digest_padding = round_to_pow2(digest_size) - digest_size |
| 2246 | |
| 2247 | # First, calculate the maximum image size such that an image |
| 2248 | # this size + the hashtree + metadata (footer + vbmeta struct) |
| 2249 | # fits in |partition_size|. We use very conservative figures for |
| 2250 | # metadata. |
| 2251 | (_, max_tree_size) = calc_hash_level_offsets( |
| 2252 | partition_size, block_size, digest_size + digest_padding) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2253 | max_fec_size = 0 |
| 2254 | if generate_fec: |
| 2255 | max_fec_size = calc_fec_data_size(partition_size, fec_num_roots) |
| 2256 | max_metadata_size = (max_fec_size + max_tree_size + |
| 2257 | self.MAX_VBMETA_SIZE + |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2258 | self.MAX_FOOTER_SIZE) |
| 2259 | max_image_size = partition_size - max_metadata_size |
| 2260 | |
| 2261 | # If we're asked to only calculate the maximum image size, we're done. |
| 2262 | if calc_max_image_size: |
| 2263 | print '{}'.format(max_image_size) |
| 2264 | return |
| 2265 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2266 | image = ImageHandler(image_filename) |
| 2267 | |
| 2268 | if partition_size % image.block_size != 0: |
| 2269 | raise AvbError('Partition size of {} is not a multiple of the image ' |
| 2270 | 'block size {}.'.format(partition_size, |
| 2271 | image.block_size)) |
| 2272 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2273 | # If there's already a footer, truncate the image to its original |
| 2274 | # size. This way 'avbtool add_hashtree_footer' is idempotent |
| 2275 | # (modulo salts). |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2276 | image.seek(image.image_size - AvbFooter.SIZE) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2277 | try: |
| 2278 | footer = AvbFooter(image.read(AvbFooter.SIZE)) |
| 2279 | # Existing footer found. Just truncate. |
| 2280 | original_image_size = footer.original_image_size |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2281 | image.truncate(footer.original_image_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2282 | except (LookupError, struct.error): |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2283 | original_image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2284 | |
| 2285 | # If anything goes wrong from here-on, restore the image back to |
| 2286 | # its original size. |
| 2287 | try: |
| 2288 | # Ensure image is multiple of block_size. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2289 | rounded_image_size = round_to_multiple(image.image_size, block_size) |
| 2290 | if rounded_image_size > image.image_size: |
| 2291 | image.append_raw('\0' * (rounded_image_size - image.image_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2292 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2293 | # If image size exceeds the maximum image size, fail. |
| 2294 | if image.image_size > max_image_size: |
| 2295 | raise AvbError('Image size of {} exceeds maximum image ' |
| 2296 | 'size of {} in order to fit in a partition ' |
| 2297 | 'size of {}.'.format(image.image_size, max_image_size, |
| 2298 | partition_size)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2299 | |
| 2300 | if salt: |
| 2301 | salt = salt.decode('hex') |
| 2302 | else: |
| 2303 | if salt is None: |
| 2304 | # If salt is not explicitly specified, choose a hash |
| 2305 | # that's the same size as the hash size. |
| 2306 | hash_size = digest_size |
| 2307 | salt = open('/dev/urandom').read(hash_size) |
| 2308 | else: |
| 2309 | salt = '' |
| 2310 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2311 | # Hashes are stored upside down so we need to calculate hash |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2312 | # offsets in advance. |
| 2313 | (hash_level_offsets, tree_size) = calc_hash_level_offsets( |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2314 | image.image_size, block_size, digest_size + digest_padding) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2315 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2316 | # If the image isn't sparse, its size might not be a multiple of |
| 2317 | # 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] | 2318 | if image.image_size % image.block_size != 0: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2319 | assert not image.is_sparse |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2320 | padding_needed = image.block_size - (image.image_size%image.block_size) |
| 2321 | image.truncate(image.image_size + padding_needed) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2322 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2323 | # Generate the tree and add padding as needed. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2324 | tree_offset = image.image_size |
| 2325 | root_digest, hash_tree = generate_hash_tree(image, image.image_size, |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2326 | block_size, |
| 2327 | hash_algorithm, salt, |
| 2328 | digest_padding, |
| 2329 | hash_level_offsets, |
| 2330 | tree_size) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2331 | |
| 2332 | # Generate HashtreeDescriptor with details about the tree we |
| 2333 | # just generated. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2334 | ht_desc = AvbHashtreeDescriptor() |
| 2335 | ht_desc.dm_verity_version = 1 |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2336 | ht_desc.image_size = image.image_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2337 | ht_desc.tree_offset = tree_offset |
| 2338 | ht_desc.tree_size = tree_size |
| 2339 | ht_desc.data_block_size = block_size |
| 2340 | ht_desc.hash_block_size = block_size |
| 2341 | ht_desc.hash_algorithm = hash_algorithm |
| 2342 | ht_desc.partition_name = partition_name |
| 2343 | ht_desc.salt = salt |
| 2344 | ht_desc.root_digest = root_digest |
| 2345 | |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2346 | # Write the hash tree |
| 2347 | padding_needed = (round_to_multiple(len(hash_tree), image.block_size) - |
| 2348 | len(hash_tree)) |
| 2349 | hash_tree_with_padding = hash_tree + '\0'*padding_needed |
| 2350 | image.append_raw(hash_tree_with_padding) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2351 | len_hashtree_and_fec = len(hash_tree_with_padding) |
| 2352 | |
| 2353 | # Generate FEC codes, if requested. |
| 2354 | if generate_fec: |
| 2355 | fec_data = generate_fec_data(image_filename, fec_num_roots) |
| 2356 | padding_needed = (round_to_multiple(len(fec_data), image.block_size) - |
| 2357 | len(fec_data)) |
| 2358 | fec_data_with_padding = fec_data + '\0'*padding_needed |
| 2359 | fec_offset = image.image_size |
| 2360 | image.append_raw(fec_data_with_padding) |
| 2361 | len_hashtree_and_fec += len(fec_data_with_padding) |
| 2362 | # Update the hashtree descriptor. |
| 2363 | ht_desc.fec_num_roots = fec_num_roots |
| 2364 | ht_desc.fec_offset = fec_offset |
| 2365 | ht_desc.fec_size = len(fec_data) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2366 | |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2367 | # Flags are only allowed on top-level vbmeta struct. |
| 2368 | flags = 0 |
| 2369 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2370 | # Generate the VBMeta footer and add padding as needed. |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2371 | vbmeta_offset = tree_offset + len_hashtree_and_fec |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2372 | vbmeta_blob = self._generate_vbmeta_blob( |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2373 | algorithm_name, key_path, public_key_metadata_path, [ht_desc], |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2374 | rollback_index, flags, props, props_from_file, kernel_cmdlines, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2375 | generate_dm_verity_cmdline_from_hashtree, |
| 2376 | include_descriptors_from_image) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2377 | padding_needed = (round_to_multiple(len(vbmeta_blob), image.block_size) - |
| 2378 | len(vbmeta_blob)) |
| 2379 | vbmeta_blob_with_padding = vbmeta_blob + '\0'*padding_needed |
| 2380 | image.append_raw(vbmeta_blob_with_padding) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2381 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2382 | # Now insert a DONT_CARE chunk with enough bytes such that the |
| 2383 | # final Footer block is at the end of partition_size.. |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2384 | image.append_dont_care(partition_size - image.image_size - |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2385 | 1*image.block_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2386 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2387 | # Generate the Footer that tells where the VBMeta footer |
| 2388 | # is. Also put enough padding in the front of the footer since |
| 2389 | # we'll write out an entire block. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2390 | footer = AvbFooter() |
| 2391 | footer.original_image_size = original_image_size |
| 2392 | footer.vbmeta_offset = vbmeta_offset |
| 2393 | footer.vbmeta_size = len(vbmeta_blob) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2394 | footer_blob = footer.encode() |
| 2395 | footer_blob_with_padding = ('\0'*(image.block_size - AvbFooter.SIZE) + |
| 2396 | footer_blob) |
| 2397 | image.append_raw(footer_blob_with_padding) |
| 2398 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2399 | except: |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2400 | # Truncate back to original size, then re-raise. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2401 | image.truncate(original_image_size) |
| 2402 | raise |
| 2403 | |
| 2404 | |
| 2405 | def calc_hash_level_offsets(image_size, block_size, digest_size): |
| 2406 | """Calculate the offsets of all the hash-levels in a Merkle-tree. |
| 2407 | |
| 2408 | Arguments: |
| 2409 | image_size: The size of the image to calculate a Merkle-tree for. |
| 2410 | block_size: The block size, e.g. 4096. |
| 2411 | digest_size: The size of each hash, e.g. 32 for SHA-256. |
| 2412 | |
| 2413 | Returns: |
| 2414 | A tuple where the first argument is an array of offsets and the |
| 2415 | second is size of the tree, in bytes. |
| 2416 | """ |
| 2417 | level_offsets = [] |
| 2418 | level_sizes = [] |
| 2419 | tree_size = 0 |
| 2420 | |
| 2421 | num_levels = 0 |
| 2422 | size = image_size |
| 2423 | while size > block_size: |
| 2424 | num_blocks = (size + block_size - 1) / block_size |
| 2425 | level_size = round_to_multiple(num_blocks * digest_size, block_size) |
| 2426 | |
| 2427 | level_sizes.append(level_size) |
| 2428 | tree_size += level_size |
| 2429 | num_levels += 1 |
| 2430 | |
| 2431 | size = level_size |
| 2432 | |
| 2433 | for n in range(0, num_levels): |
| 2434 | offset = 0 |
| 2435 | for m in range(n + 1, num_levels): |
| 2436 | offset += level_sizes[m] |
| 2437 | level_offsets.append(offset) |
| 2438 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2439 | return level_offsets, tree_size |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2440 | |
| 2441 | |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2442 | # See system/extras/libfec/include/fec/io.h for these definitions. |
| 2443 | FEC_FOOTER_FORMAT = '<LLLLLQ32s' |
| 2444 | FEC_MAGIC = 0xfecfecfe |
| 2445 | |
| 2446 | |
| 2447 | def calc_fec_data_size(image_size, num_roots): |
| 2448 | """Calculates how much space FEC data will take. |
| 2449 | |
| 2450 | Args: |
| 2451 | image_size: The size of the image. |
| 2452 | num_roots: Number of roots. |
| 2453 | |
| 2454 | Returns: |
| 2455 | The number of bytes needed for FEC for an image of the given size |
| 2456 | and with the requested number of FEC roots. |
| 2457 | |
| 2458 | Raises: |
| 2459 | ValueError: If output from the 'fec' tool is invalid. |
| 2460 | |
| 2461 | """ |
| 2462 | p = subprocess.Popen( |
| 2463 | ['fec', '--print-fec-size', str(image_size), '--roots', str(num_roots)], |
| 2464 | stdout=subprocess.PIPE, |
| 2465 | stderr=subprocess.PIPE) |
| 2466 | (pout, perr) = p.communicate() |
| 2467 | retcode = p.wait() |
| 2468 | if retcode != 0: |
| 2469 | raise ValueError('Error invoking fec: {}'.format(perr)) |
| 2470 | return int(pout) |
| 2471 | |
| 2472 | |
| 2473 | def generate_fec_data(image_filename, num_roots): |
| 2474 | """Generate FEC codes for an image. |
| 2475 | |
| 2476 | Args: |
| 2477 | image_filename: The filename of the image. |
| 2478 | num_roots: Number of roots. |
| 2479 | |
| 2480 | Returns: |
| 2481 | The FEC data blob. |
| 2482 | |
| 2483 | Raises: |
| 2484 | ValueError: If output from the 'fec' tool is invalid. |
| 2485 | """ |
| 2486 | fec_tmpfile = tempfile.NamedTemporaryFile() |
| 2487 | subprocess.check_call( |
| 2488 | ['fec', '--encode', '--roots', str(num_roots), image_filename, |
| 2489 | fec_tmpfile.name], |
| 2490 | stderr=open(os.devnull)) |
| 2491 | fec_data = fec_tmpfile.read() |
| 2492 | footer_size = struct.calcsize(FEC_FOOTER_FORMAT) |
| 2493 | footer_data = fec_data[-footer_size:] |
| 2494 | (magic, _, _, num_roots, fec_size, _, _) = struct.unpack(FEC_FOOTER_FORMAT, |
| 2495 | footer_data) |
| 2496 | if magic != FEC_MAGIC: |
| 2497 | raise ValueError('Unexpected magic in FEC footer') |
| 2498 | return fec_data[0:fec_size] |
| 2499 | |
| 2500 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2501 | 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] | 2502 | digest_padding, hash_level_offsets, tree_size): |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2503 | """Generates a Merkle-tree for a file. |
| 2504 | |
| 2505 | Args: |
| 2506 | image: The image, as a file. |
| 2507 | image_size: The size of the image. |
| 2508 | block_size: The block size, e.g. 4096. |
| 2509 | hash_alg_name: The hash algorithm, e.g. 'sha256' or 'sha1'. |
| 2510 | salt: The salt to use. |
| 2511 | digest_padding: The padding for each digest. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2512 | hash_level_offsets: The offsets from calc_hash_level_offsets(). |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2513 | tree_size: The size of the tree, in number of bytes. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2514 | |
| 2515 | Returns: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2516 | A tuple where the first element is the top-level hash and the |
| 2517 | second element is the hash-tree. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2518 | """ |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2519 | hash_ret = bytearray(tree_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2520 | hash_src_offset = 0 |
| 2521 | hash_src_size = image_size |
| 2522 | level_num = 0 |
| 2523 | while hash_src_size > block_size: |
| 2524 | level_output = '' |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2525 | remaining = hash_src_size |
| 2526 | while remaining > 0: |
| 2527 | hasher = hashlib.new(name=hash_alg_name, string=salt) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2528 | # Only read from the file for the first level - for subsequent |
| 2529 | # levels, access the array we're building. |
| 2530 | if level_num == 0: |
| 2531 | image.seek(hash_src_offset + hash_src_size - remaining) |
| 2532 | data = image.read(min(remaining, block_size)) |
| 2533 | else: |
| 2534 | offset = hash_level_offsets[level_num - 1] + hash_src_size - remaining |
| 2535 | data = hash_ret[offset:offset + block_size] |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2536 | hasher.update(data) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2537 | |
| 2538 | remaining -= len(data) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2539 | if len(data) < block_size: |
| 2540 | hasher.update('\0' * (block_size - len(data))) |
| 2541 | level_output += hasher.digest() |
| 2542 | if digest_padding > 0: |
| 2543 | level_output += '\0' * digest_padding |
| 2544 | |
| 2545 | padding_needed = (round_to_multiple( |
| 2546 | len(level_output), block_size) - len(level_output)) |
| 2547 | level_output += '\0' * padding_needed |
| 2548 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2549 | # Copy level-output into resulting tree. |
| 2550 | offset = hash_level_offsets[level_num] |
| 2551 | hash_ret[offset:offset + len(level_output)] = level_output |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2552 | |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2553 | # Continue on to the next level. |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2554 | hash_src_size = len(level_output) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2555 | level_num += 1 |
| 2556 | |
| 2557 | hasher = hashlib.new(name=hash_alg_name, string=salt) |
| 2558 | hasher.update(level_output) |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2559 | return hasher.digest(), hash_ret |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2560 | |
| 2561 | |
| 2562 | class AvbTool(object): |
| 2563 | """Object for avbtool command-line tool.""" |
| 2564 | |
| 2565 | def __init__(self): |
| 2566 | """Initializer method.""" |
| 2567 | self.avb = Avb() |
| 2568 | |
| 2569 | def _add_common_args(self, sub_parser): |
| 2570 | """Adds arguments used by several sub-commands. |
| 2571 | |
| 2572 | Arguments: |
| 2573 | sub_parser: The parser to add arguments to. |
| 2574 | """ |
| 2575 | sub_parser.add_argument('--algorithm', |
| 2576 | help='Algorithm to use (default: NONE)', |
| 2577 | metavar='ALGORITHM', |
| 2578 | default='NONE') |
| 2579 | sub_parser.add_argument('--key', |
| 2580 | help='Path to RSA private key file', |
| 2581 | metavar='KEY', |
| 2582 | required=False) |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2583 | sub_parser.add_argument('--public_key_metadata', |
| 2584 | help='Path to public key metadata file', |
| 2585 | metavar='KEY_METADATA', |
| 2586 | required=False) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2587 | sub_parser.add_argument('--rollback_index', |
| 2588 | help='Rollback Index', |
| 2589 | type=parse_number, |
| 2590 | default=0) |
| 2591 | sub_parser.add_argument('--prop', |
| 2592 | help='Add property', |
| 2593 | metavar='KEY:VALUE', |
| 2594 | action='append') |
| 2595 | sub_parser.add_argument('--prop_from_file', |
| 2596 | help='Add property from file', |
| 2597 | metavar='KEY:PATH', |
| 2598 | action='append') |
| 2599 | sub_parser.add_argument('--kernel_cmdline', |
| 2600 | help='Add kernel cmdline', |
| 2601 | metavar='CMDLINE', |
| 2602 | action='append') |
| 2603 | sub_parser.add_argument('--generate_dm_verity_cmdline_from_hashtree', |
| 2604 | metavar='IMAGE', |
| 2605 | help='Generate kernel cmdline for dm-verity', |
| 2606 | type=argparse.FileType('rb')) |
| 2607 | sub_parser.add_argument('--include_descriptors_from_image', |
| 2608 | help='Include descriptors from image', |
| 2609 | metavar='IMAGE', |
| 2610 | action='append', |
| 2611 | type=argparse.FileType('rb')) |
| 2612 | |
| 2613 | def run(self, argv): |
| 2614 | """Command-line processor. |
| 2615 | |
| 2616 | Arguments: |
| 2617 | argv: Pass sys.argv from main. |
| 2618 | """ |
| 2619 | parser = argparse.ArgumentParser() |
| 2620 | subparsers = parser.add_subparsers(title='subcommands') |
| 2621 | |
| 2622 | sub_parser = subparsers.add_parser('version', |
| 2623 | help='Prints version of avbtool.') |
| 2624 | sub_parser.set_defaults(func=self.version) |
| 2625 | |
| 2626 | sub_parser = subparsers.add_parser('extract_public_key', |
| 2627 | help='Extract public key.') |
| 2628 | sub_parser.add_argument('--key', |
| 2629 | help='Path to RSA private key file', |
| 2630 | required=True) |
| 2631 | sub_parser.add_argument('--output', |
| 2632 | help='Output file name', |
| 2633 | type=argparse.FileType('wb'), |
| 2634 | required=True) |
| 2635 | sub_parser.set_defaults(func=self.extract_public_key) |
| 2636 | |
| 2637 | sub_parser = subparsers.add_parser('make_vbmeta_image', |
| 2638 | help='Makes a vbmeta image.') |
| 2639 | sub_parser.add_argument('--output', |
| 2640 | help='Output file name', |
| 2641 | type=argparse.FileType('wb'), |
| 2642 | required=True) |
| 2643 | self._add_common_args(sub_parser) |
| 2644 | sub_parser.add_argument('--chain_partition', |
| 2645 | help='Allow signed integrity-data for partition', |
| 2646 | metavar='PART_NAME:ROLLBACK_SLOT:KEY_PATH', |
| 2647 | action='append') |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2648 | sub_parser.add_argument('--flags', |
| 2649 | help='VBMeta flags', |
| 2650 | type=parse_number, |
| 2651 | default=0) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2652 | sub_parser.set_defaults(func=self.make_vbmeta_image) |
| 2653 | |
| 2654 | sub_parser = subparsers.add_parser('add_hash_footer', |
| 2655 | help='Add hashes and footer to image.') |
| 2656 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2657 | help='Image to add hashes to', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2658 | type=argparse.FileType('rab+')) |
| 2659 | sub_parser.add_argument('--partition_size', |
| 2660 | help='Partition size', |
| 2661 | type=parse_number, |
| 2662 | required=True) |
| 2663 | sub_parser.add_argument('--partition_name', |
| 2664 | help='Partition name', |
| 2665 | required=True) |
| 2666 | sub_parser.add_argument('--hash_algorithm', |
| 2667 | help='Hash algorithm to use (default: sha256)', |
| 2668 | default='sha256') |
| 2669 | sub_parser.add_argument('--salt', |
| 2670 | help='Salt in hex (default: /dev/urandom)') |
| 2671 | self._add_common_args(sub_parser) |
| 2672 | sub_parser.set_defaults(func=self.add_hash_footer) |
| 2673 | |
| 2674 | sub_parser = subparsers.add_parser('add_hashtree_footer', |
| 2675 | help='Add hashtree and footer to image.') |
| 2676 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2677 | help='Image to add hashtree to', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2678 | type=argparse.FileType('rab+')) |
| 2679 | sub_parser.add_argument('--partition_size', |
| 2680 | help='Partition size', |
| 2681 | type=parse_number, |
| 2682 | required=True) |
| 2683 | sub_parser.add_argument('--partition_name', |
| 2684 | help='Partition name', |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2685 | default=None) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2686 | sub_parser.add_argument('--hash_algorithm', |
| 2687 | help='Hash algorithm to use (default: sha1)', |
| 2688 | default='sha1') |
| 2689 | sub_parser.add_argument('--salt', |
| 2690 | help='Salt in hex (default: /dev/urandom)') |
| 2691 | sub_parser.add_argument('--block_size', |
| 2692 | help='Block size (default: 4096)', |
| 2693 | type=parse_number, |
| 2694 | default=4096) |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2695 | sub_parser.add_argument('--generate_fec', |
| 2696 | help='Add forward-error-correction codes', |
| 2697 | action='store_true') |
| 2698 | sub_parser.add_argument('--fec_num_roots', |
| 2699 | help='Number of roots for FEC (default: 2)', |
| 2700 | type=parse_number, |
| 2701 | default=2) |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2702 | sub_parser.add_argument('--calc_max_image_size', |
| 2703 | help=('Don\'t store the hashtree or footer - ' |
| 2704 | 'instead calculate the maximum image size ' |
| 2705 | 'leaving enough room for hashtree ' |
| 2706 | 'and metadata with the given partition ' |
| 2707 | 'size.'), |
| 2708 | action='store_true') |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2709 | self._add_common_args(sub_parser) |
| 2710 | sub_parser.set_defaults(func=self.add_hashtree_footer) |
| 2711 | |
| 2712 | sub_parser = subparsers.add_parser('erase_footer', |
| 2713 | help='Erase footer from an image.') |
| 2714 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2715 | help='Image with a footer', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2716 | type=argparse.FileType('rwb+'), |
| 2717 | required=True) |
| 2718 | sub_parser.add_argument('--keep_hashtree', |
| 2719 | help='Keep the hashtree in the image', |
| 2720 | action='store_true') |
| 2721 | sub_parser.set_defaults(func=self.erase_footer) |
| 2722 | |
| 2723 | sub_parser = subparsers.add_parser( |
| 2724 | 'info_image', |
| 2725 | help='Show information about vbmeta or footer.') |
| 2726 | sub_parser.add_argument('--image', |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2727 | help='Image to show information about', |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2728 | type=argparse.FileType('rb'), |
| 2729 | required=True) |
| 2730 | sub_parser.add_argument('--output', |
| 2731 | help='Write info to file', |
| 2732 | type=argparse.FileType('wt'), |
| 2733 | default=sys.stdout) |
| 2734 | sub_parser.set_defaults(func=self.info_image) |
| 2735 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2736 | sub_parser = subparsers.add_parser('set_ab_metadata', |
| 2737 | help='Set A/B metadata.') |
| 2738 | sub_parser.add_argument('--misc_image', |
| 2739 | help=('The misc image to modify. If the image does ' |
| 2740 | 'not exist, it will be created.'), |
| 2741 | type=argparse.FileType('r+b'), |
| 2742 | required=True) |
| 2743 | sub_parser.add_argument('--slot_data', |
| 2744 | help=('Slot data of the form "priority", ' |
| 2745 | '"tries_remaining", "sucessful_boot" for ' |
| 2746 | 'slot A followed by the same for slot B, ' |
| 2747 | 'separated by colons. The default value ' |
| 2748 | 'is 15:7:0:14:7:0.'), |
| 2749 | default='15:7:0:14:7:0') |
| 2750 | sub_parser.set_defaults(func=self.set_ab_metadata) |
| 2751 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2752 | args = parser.parse_args(argv[1:]) |
| 2753 | try: |
| 2754 | args.func(args) |
| 2755 | except AvbError as e: |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2756 | sys.stderr.write('{}: {}\n'.format(argv[0], e.message)) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2757 | sys.exit(1) |
| 2758 | |
| 2759 | def version(self, _): |
| 2760 | """Implements the 'version' sub-command.""" |
| 2761 | print '{}.{}'.format(AVB_VERSION_MAJOR, AVB_VERSION_MINOR) |
| 2762 | |
| 2763 | def extract_public_key(self, args): |
| 2764 | """Implements the 'extract_public_key' sub-command.""" |
| 2765 | self.avb.extract_public_key(args.key, args.output) |
| 2766 | |
| 2767 | def make_vbmeta_image(self, args): |
| 2768 | """Implements the 'make_vbmeta_image' sub-command.""" |
| 2769 | self.avb.make_vbmeta_image(args.output, args.chain_partition, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2770 | args.algorithm, args.key, |
| 2771 | args.public_key_metadata, args.rollback_index, |
David Zeuthen | fd41eb9 | 2016-11-17 12:24:47 -0500 | [diff] [blame] | 2772 | args.flags, args.prop, args.prop_from_file, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2773 | args.kernel_cmdline, |
| 2774 | args.generate_dm_verity_cmdline_from_hashtree, |
| 2775 | args.include_descriptors_from_image) |
| 2776 | |
| 2777 | def add_hash_footer(self, args): |
| 2778 | """Implements the 'add_hash_footer' sub-command.""" |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2779 | self.avb.add_hash_footer(args.image.name, args.partition_size, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2780 | args.partition_name, args.hash_algorithm, |
| 2781 | args.salt, args.algorithm, args.key, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2782 | args.public_key_metadata, args.rollback_index, |
| 2783 | args.prop, args.prop_from_file, |
| 2784 | args.kernel_cmdline, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2785 | args.generate_dm_verity_cmdline_from_hashtree, |
| 2786 | args.include_descriptors_from_image) |
| 2787 | |
| 2788 | def add_hashtree_footer(self, args): |
| 2789 | """Implements the 'add_hashtree_footer' sub-command.""" |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2790 | self.avb.add_hashtree_footer(args.image.name if args.image else None, |
| 2791 | args.partition_size, |
| 2792 | args.partition_name, |
David Zeuthen | 0b7f1d3 | 2016-10-25 17:53:49 -0400 | [diff] [blame] | 2793 | args.generate_fec, args.fec_num_roots, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2794 | args.hash_algorithm, args.block_size, |
| 2795 | args.salt, args.algorithm, args.key, |
David Zeuthen | 18666ab | 2016-11-15 11:18:05 -0500 | [diff] [blame] | 2796 | args.public_key_metadata, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2797 | args.rollback_index, args.prop, |
| 2798 | args.prop_from_file, |
| 2799 | args.kernel_cmdline, |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2800 | args.generate_dm_verity_cmdline_from_hashtree, |
David Zeuthen | 0969269 | 2016-09-30 16:16:40 -0400 | [diff] [blame] | 2801 | args.include_descriptors_from_image, |
| 2802 | args.calc_max_image_size) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2803 | |
| 2804 | def erase_footer(self, args): |
| 2805 | """Implements the 'erase_footer' sub-command.""" |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2806 | self.avb.erase_footer(args.image.name, args.keep_hashtree) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2807 | |
David Zeuthen | 8b6973b | 2016-09-20 12:39:49 -0400 | [diff] [blame] | 2808 | def set_ab_metadata(self, args): |
| 2809 | """Implements the 'set_ab_metadata' sub-command.""" |
| 2810 | self.avb.set_ab_metadata(args.misc_image, args.slot_data) |
| 2811 | |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2812 | def info_image(self, args): |
| 2813 | """Implements the 'info_image' sub-command.""" |
David Zeuthen | a4fee8b | 2016-08-22 15:20:43 -0400 | [diff] [blame] | 2814 | self.avb.info_image(args.image.name, args.output) |
David Zeuthen | 21e9526 | 2016-07-27 17:58:40 -0400 | [diff] [blame] | 2815 | |
| 2816 | |
| 2817 | if __name__ == '__main__': |
| 2818 | tool = AvbTool() |
| 2819 | tool.run(sys.argv) |