Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2009 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include <stdio.h> |
| 18 | #include <stdint.h> |
| 19 | #include <string.h> |
| 20 | #include <unistd.h> |
| 21 | #include <signal.h> |
| 22 | #include <errno.h> |
| 23 | #include <dirent.h> |
| 24 | #include <fcntl.h> |
| 25 | #include <limits.h> |
| 26 | #include <sys/types.h> |
| 27 | #include <sys/socket.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <sys/time.h> |
| 30 | #include <arpa/inet.h> |
| 31 | |
| 32 | #include <openssl/aes.h> |
| 33 | #include <openssl/evp.h> |
| 34 | #include <openssl/md5.h> |
| 35 | |
| 36 | #define LOG_TAG "keystore" |
| 37 | #include <cutils/log.h> |
| 38 | #include <cutils/sockets.h> |
| 39 | #include <private/android_filesystem_config.h> |
| 40 | |
| 41 | #include "keystore.h" |
| 42 | |
| 43 | /* KeyStore is a secured storage for key-value pairs. In this implementation, |
| 44 | * each file stores one key-value pair. Keys are encoded in file names, and |
| 45 | * values are encrypted with checksums. The encryption key is protected by a |
| 46 | * user-defined password. To keep things simple, buffers are always larger than |
| 47 | * the maximum space we needed, so boundary checks on buffers are omitted. */ |
| 48 | |
Chia-chi Yeh | e3bc023 | 2010-03-09 09:41:32 +0800 | [diff] [blame] | 49 | #define KEY_SIZE ((NAME_MAX - 15) / 2) |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 50 | #define VALUE_SIZE 32768 |
| 51 | #define PASSWORD_SIZE VALUE_SIZE |
| 52 | |
| 53 | /* Here is the encoding of keys. This is necessary in order to allow arbitrary |
| 54 | * characters in keys. Characters in [0-~] are not encoded. Others are encoded |
| 55 | * into two bytes. The first byte is one of [+-.] which represents the first |
| 56 | * two bits of the character. The second byte encodes the rest of the bits into |
| 57 | * [0-o]. Therefore in the worst case the length of a key gets doubled. Note |
| 58 | * that Base64 cannot be used here due to the need of prefix match on keys. */ |
| 59 | |
| 60 | static int encode_key(char *out, uint8_t *in, int length) |
| 61 | { |
| 62 | int i; |
| 63 | for (i = length; i > 0; --i, ++in, ++out) { |
| 64 | if (*in >= '0' && *in <= '~') { |
| 65 | *out = *in; |
| 66 | } else { |
| 67 | *out = '+' + (*in >> 6); |
| 68 | *++out = '0' + (*in & 0x3F); |
| 69 | ++length; |
| 70 | } |
| 71 | } |
| 72 | *out = 0; |
| 73 | return length; |
| 74 | } |
| 75 | |
| 76 | static int decode_key(uint8_t *out, char *in, int length) |
| 77 | { |
| 78 | int i; |
| 79 | for (i = 0; i < length; ++i, ++in, ++out) { |
| 80 | if (*in >= '0' && *in <= '~') { |
| 81 | *out = *in; |
| 82 | } else { |
| 83 | *out = (*in - '+') << 6; |
| 84 | *out |= (*++in - '0') & 0x3F; |
| 85 | --length; |
| 86 | } |
| 87 | } |
| 88 | *out = 0; |
| 89 | return length; |
| 90 | } |
| 91 | |
| 92 | /* Here is the protocol used in both requests and responses: |
| 93 | * code [length_1 message_1 ... length_n message_n] end-of-file |
| 94 | * where code is one byte long and lengths are unsigned 16-bit integers in |
| 95 | * network order. Thus the maximum length of a message is 65535 bytes. */ |
| 96 | |
| 97 | static int the_socket = -1; |
| 98 | |
| 99 | static int recv_code(int8_t *code) |
| 100 | { |
| 101 | return recv(the_socket, code, 1, 0) == 1; |
| 102 | } |
| 103 | |
| 104 | static int recv_message(uint8_t *message, int length) |
| 105 | { |
| 106 | uint8_t bytes[2]; |
| 107 | if (recv(the_socket, &bytes[0], 1, 0) != 1 || |
| 108 | recv(the_socket, &bytes[1], 1, 0) != 1) { |
| 109 | return -1; |
| 110 | } else { |
| 111 | int offset = bytes[0] << 8 | bytes[1]; |
| 112 | if (length < offset) { |
| 113 | return -1; |
| 114 | } |
| 115 | length = offset; |
| 116 | offset = 0; |
| 117 | while (offset < length) { |
| 118 | int n = recv(the_socket, &message[offset], length - offset, 0); |
| 119 | if (n <= 0) { |
| 120 | return -1; |
| 121 | } |
| 122 | offset += n; |
| 123 | } |
| 124 | } |
| 125 | return length; |
| 126 | } |
| 127 | |
Chia-chi Yeh | dd2a71e | 2009-09-20 10:15:46 +0800 | [diff] [blame] | 128 | static int recv_end_of_file() |
| 129 | { |
| 130 | uint8_t byte; |
| 131 | return recv(the_socket, &byte, 1, 0) == 0; |
| 132 | } |
| 133 | |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 134 | static void send_code(int8_t code) |
| 135 | { |
| 136 | send(the_socket, &code, 1, 0); |
| 137 | } |
| 138 | |
| 139 | static void send_message(uint8_t *message, int length) |
| 140 | { |
| 141 | uint16_t bytes = htons(length); |
| 142 | send(the_socket, &bytes, 2, 0); |
| 143 | send(the_socket, message, length, 0); |
| 144 | } |
| 145 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 146 | /* Here is the file format. There are two parts in blob.value, the secret and |
| 147 | * the description. The secret is stored in ciphertext, and its original size |
| 148 | * can be found in blob.length. The description is stored after the secret in |
| 149 | * plaintext, and its size is specified in blob.info. The total size of the two |
| 150 | * parts must be no more than VALUE_SIZE bytes. The first three bytes of the |
| 151 | * file are reserved for future use and are always set to zero. Fields other |
| 152 | * than blob.info, blob.length, and blob.value are modified by encrypt_blob() |
| 153 | * and decrypt_blob(). Thus they should not be accessed from outside. */ |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 154 | |
| 155 | static int the_entropy = -1; |
| 156 | |
| 157 | static struct __attribute__((packed)) { |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 158 | uint8_t reserved[3]; |
| 159 | uint8_t info; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 160 | uint8_t vector[AES_BLOCK_SIZE]; |
| 161 | uint8_t encrypted[0]; |
| 162 | uint8_t digest[MD5_DIGEST_LENGTH]; |
| 163 | uint8_t digested[0]; |
| 164 | int32_t length; |
| 165 | uint8_t value[VALUE_SIZE + AES_BLOCK_SIZE]; |
| 166 | } blob; |
| 167 | |
| 168 | static int8_t encrypt_blob(char *name, AES_KEY *aes_key) |
| 169 | { |
| 170 | uint8_t vector[AES_BLOCK_SIZE]; |
Chia-chi Yeh | ced6625 | 2009-12-22 17:02:45 +0800 | [diff] [blame] | 171 | int length; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 172 | int fd; |
| 173 | |
Chia-chi Yeh | 857edec | 2010-09-30 17:28:01 +0800 | [diff] [blame] | 174 | if (read(the_entropy, blob.vector, AES_BLOCK_SIZE) != AES_BLOCK_SIZE) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 175 | return SYSTEM_ERROR; |
| 176 | } |
| 177 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 178 | length = blob.length + (blob.value - blob.encrypted); |
Chia-chi Yeh | b78679e | 2009-12-30 10:38:39 +0800 | [diff] [blame] | 179 | length = (length + AES_BLOCK_SIZE - 1) / AES_BLOCK_SIZE * AES_BLOCK_SIZE; |
Chia-chi Yeh | ced6625 | 2009-12-22 17:02:45 +0800 | [diff] [blame] | 180 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 181 | if (blob.info != 0) { |
| 182 | memmove(&blob.encrypted[length], &blob.value[blob.length], blob.info); |
| 183 | } |
| 184 | |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 185 | blob.length = htonl(blob.length); |
Chia-chi Yeh | b78679e | 2009-12-30 10:38:39 +0800 | [diff] [blame] | 186 | MD5(blob.digested, length - (blob.digested - blob.encrypted), blob.digest); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 187 | |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 188 | memcpy(vector, blob.vector, AES_BLOCK_SIZE); |
| 189 | AES_cbc_encrypt(blob.encrypted, blob.encrypted, length, aes_key, vector, |
| 190 | AES_ENCRYPT); |
| 191 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 192 | memset(blob.reserved, 0, sizeof(blob.reserved)); |
| 193 | length += (blob.encrypted - (uint8_t *)&blob) + blob.info; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 194 | |
| 195 | fd = open(".tmp", O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR); |
Chia-chi Yeh | ced6625 | 2009-12-22 17:02:45 +0800 | [diff] [blame] | 196 | length -= write(fd, &blob, length); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 197 | close(fd); |
Chia-chi Yeh | ced6625 | 2009-12-22 17:02:45 +0800 | [diff] [blame] | 198 | return (length || rename(".tmp", name)) ? SYSTEM_ERROR : NO_ERROR; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 199 | } |
| 200 | |
| 201 | static int8_t decrypt_blob(char *name, AES_KEY *aes_key) |
| 202 | { |
| 203 | int fd = open(name, O_RDONLY); |
| 204 | int length; |
| 205 | |
| 206 | if (fd == -1) { |
| 207 | return (errno == ENOENT) ? KEY_NOT_FOUND : SYSTEM_ERROR; |
| 208 | } |
| 209 | length = read(fd, &blob, sizeof(blob)); |
| 210 | close(fd); |
| 211 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 212 | length -= (blob.encrypted - (uint8_t *)&blob) + blob.info; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 213 | if (length < blob.value - blob.encrypted || length % AES_BLOCK_SIZE != 0) { |
| 214 | return VALUE_CORRUPTED; |
| 215 | } |
| 216 | |
| 217 | AES_cbc_encrypt(blob.encrypted, blob.encrypted, length, aes_key, |
| 218 | blob.vector, AES_DECRYPT); |
| 219 | length -= blob.digested - blob.encrypted; |
Chia-chi Yeh | ced6625 | 2009-12-22 17:02:45 +0800 | [diff] [blame] | 220 | if (memcmp(blob.digest, MD5(blob.digested, length, NULL), |
| 221 | MD5_DIGEST_LENGTH)) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 222 | return VALUE_CORRUPTED; |
| 223 | } |
| 224 | |
| 225 | length -= blob.value - blob.digested; |
| 226 | blob.length = ntohl(blob.length); |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 227 | if (blob.length < 0 || blob.length > length) { |
| 228 | return VALUE_CORRUPTED; |
| 229 | } |
| 230 | if (blob.info != 0) { |
| 231 | memmove(&blob.value[blob.length], &blob.value[length], blob.info); |
| 232 | } |
| 233 | return NO_ERROR; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 234 | } |
| 235 | |
| 236 | /* Here are the actions. Each of them is a function without arguments. All |
| 237 | * information is defined in global variables, which are set properly before |
| 238 | * performing an action. The number of parameters required by each action is |
Chia-chi Yeh | 2f3b2a5 | 2009-09-18 17:23:53 +0800 | [diff] [blame] | 239 | * fixed and defined in a table. If the return value of an action is positive, |
| 240 | * it will be treated as a response code and transmitted to the client. Note |
| 241 | * that the lengths of parameters are checked when they are received, so |
| 242 | * boundary checks on parameters are omitted. */ |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 243 | |
| 244 | #define MAX_PARAM 2 |
| 245 | #define MAX_RETRY 4 |
| 246 | |
| 247 | static uid_t uid = -1; |
| 248 | static int8_t state = UNINITIALIZED; |
| 249 | static int8_t retry = MAX_RETRY; |
| 250 | |
| 251 | static struct { |
| 252 | int length; |
| 253 | uint8_t value[VALUE_SIZE]; |
| 254 | } params[MAX_PARAM]; |
| 255 | |
| 256 | static AES_KEY encryption_key; |
| 257 | static AES_KEY decryption_key; |
| 258 | |
| 259 | static int8_t test() |
| 260 | { |
| 261 | return state; |
| 262 | } |
| 263 | |
| 264 | static int8_t get() |
| 265 | { |
| 266 | char name[NAME_MAX]; |
| 267 | int n = sprintf(name, "%u_", uid); |
| 268 | encode_key(&name[n], params[0].value, params[0].length); |
| 269 | n = decrypt_blob(name, &decryption_key); |
| 270 | if (n != NO_ERROR) { |
| 271 | return n; |
| 272 | } |
| 273 | send_code(NO_ERROR); |
| 274 | send_message(blob.value, blob.length); |
| 275 | return -NO_ERROR; |
| 276 | } |
| 277 | |
| 278 | static int8_t insert() |
| 279 | { |
| 280 | char name[NAME_MAX]; |
| 281 | int n = sprintf(name, "%u_", uid); |
| 282 | encode_key(&name[n], params[0].value, params[0].length); |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 283 | blob.info = 0; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 284 | blob.length = params[1].length; |
| 285 | memcpy(blob.value, params[1].value, params[1].length); |
| 286 | return encrypt_blob(name, &encryption_key); |
| 287 | } |
| 288 | |
| 289 | static int8_t delete() |
| 290 | { |
| 291 | char name[NAME_MAX]; |
| 292 | int n = sprintf(name, "%u_", uid); |
| 293 | encode_key(&name[n], params[0].value, params[0].length); |
| 294 | return (unlink(name) && errno != ENOENT) ? SYSTEM_ERROR : NO_ERROR; |
| 295 | } |
| 296 | |
| 297 | static int8_t exist() |
| 298 | { |
| 299 | char name[NAME_MAX]; |
| 300 | int n = sprintf(name, "%u_", uid); |
| 301 | encode_key(&name[n], params[0].value, params[0].length); |
| 302 | if (access(name, R_OK) == -1) { |
| 303 | return (errno != ENOENT) ? SYSTEM_ERROR : KEY_NOT_FOUND; |
| 304 | } |
| 305 | return NO_ERROR; |
| 306 | } |
| 307 | |
Chia-chi Yeh | 1cdc2a4 | 2009-09-22 02:57:52 +0800 | [diff] [blame] | 308 | static int8_t saw() |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 309 | { |
| 310 | DIR *dir = opendir("."); |
| 311 | struct dirent *file; |
| 312 | char name[NAME_MAX]; |
| 313 | int n; |
| 314 | |
| 315 | if (!dir) { |
| 316 | return SYSTEM_ERROR; |
| 317 | } |
| 318 | n = sprintf(name, "%u_", uid); |
| 319 | n += encode_key(&name[n], params[0].value, params[0].length); |
| 320 | send_code(NO_ERROR); |
| 321 | while ((file = readdir(dir)) != NULL) { |
| 322 | if (!strncmp(name, file->d_name, n)) { |
| 323 | char *p = &file->d_name[n]; |
| 324 | params[0].length = decode_key(params[0].value, p, strlen(p)); |
| 325 | send_message(params[0].value, params[0].length); |
| 326 | } |
| 327 | } |
| 328 | closedir(dir); |
| 329 | return -NO_ERROR; |
| 330 | } |
| 331 | |
| 332 | static int8_t reset() |
| 333 | { |
| 334 | DIR *dir = opendir("."); |
| 335 | struct dirent *file; |
| 336 | |
| 337 | memset(&encryption_key, 0, sizeof(encryption_key)); |
| 338 | memset(&decryption_key, 0, sizeof(decryption_key)); |
| 339 | state = UNINITIALIZED; |
| 340 | retry = MAX_RETRY; |
| 341 | |
| 342 | if (!dir) { |
| 343 | return SYSTEM_ERROR; |
| 344 | } |
| 345 | while ((file = readdir(dir)) != NULL) { |
Chia-chi Yeh | 2f3b2a5 | 2009-09-18 17:23:53 +0800 | [diff] [blame] | 346 | unlink(file->d_name); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 347 | } |
| 348 | closedir(dir); |
Chia-chi Yeh | 2f3b2a5 | 2009-09-18 17:23:53 +0800 | [diff] [blame] | 349 | return NO_ERROR; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 350 | } |
| 351 | |
| 352 | #define MASTER_KEY_FILE ".masterkey" |
| 353 | #define MASTER_KEY_SIZE 16 |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 354 | #define SALT_SIZE 16 |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 355 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 356 | static void set_key(uint8_t *key, uint8_t *password, int length, uint8_t *salt) |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 357 | { |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 358 | if (salt) { |
| 359 | PKCS5_PBKDF2_HMAC_SHA1((char *)password, length, salt, SALT_SIZE, |
| 360 | 8192, MASTER_KEY_SIZE, key); |
| 361 | } else { |
| 362 | PKCS5_PBKDF2_HMAC_SHA1((char *)password, length, (uint8_t *)"keystore", |
| 363 | sizeof("keystore"), 1024, MASTER_KEY_SIZE, key); |
| 364 | } |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 365 | } |
| 366 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 367 | /* Here is the history. To improve the security, the parameters to generate the |
| 368 | * master key has been changed. To make a seamless transition, we update the |
| 369 | * file using the same password when the user unlock it for the first time. If |
| 370 | * any thing goes wrong during the transition, the new file will not overwrite |
| 371 | * the old one. This avoids permanent damages of the existing data. */ |
| 372 | |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 373 | static int8_t password() |
| 374 | { |
| 375 | uint8_t key[MASTER_KEY_SIZE]; |
| 376 | AES_KEY aes_key; |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 377 | int8_t response = SYSTEM_ERROR; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 378 | |
| 379 | if (state == UNINITIALIZED) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 380 | if (read(the_entropy, blob.value, MASTER_KEY_SIZE) != MASTER_KEY_SIZE) { |
| 381 | return SYSTEM_ERROR; |
| 382 | } |
| 383 | } else { |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 384 | int fd = open(MASTER_KEY_FILE, O_RDONLY); |
| 385 | uint8_t *salt = NULL; |
| 386 | if (fd != -1) { |
| 387 | int length = read(fd, &blob, sizeof(blob)); |
| 388 | close(fd); |
| 389 | if (length > SALT_SIZE && blob.info == SALT_SIZE) { |
| 390 | salt = (uint8_t *)&blob + length - SALT_SIZE; |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | set_key(key, params[0].value, params[0].length, salt); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 395 | AES_set_decrypt_key(key, MASTER_KEY_SIZE * 8, &aes_key); |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 396 | response = decrypt_blob(MASTER_KEY_FILE, &aes_key); |
| 397 | if (response == SYSTEM_ERROR) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 398 | return SYSTEM_ERROR; |
| 399 | } |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 400 | if (response != NO_ERROR || blob.length != MASTER_KEY_SIZE) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 401 | if (retry <= 0) { |
Chia-chi Yeh | dd2a71e | 2009-09-20 10:15:46 +0800 | [diff] [blame] | 402 | reset(); |
| 403 | return UNINITIALIZED; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 404 | } |
| 405 | return WRONG_PASSWORD + --retry; |
| 406 | } |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 407 | |
| 408 | if (!salt && params[1].length == -1) { |
| 409 | params[1] = params[0]; |
| 410 | } |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 411 | } |
| 412 | |
| 413 | if (params[1].length == -1) { |
| 414 | memcpy(key, blob.value, MASTER_KEY_SIZE); |
| 415 | } else { |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 416 | uint8_t *salt = &blob.value[MASTER_KEY_SIZE]; |
| 417 | if (read(the_entropy, salt, SALT_SIZE) != SALT_SIZE) { |
| 418 | return SYSTEM_ERROR; |
| 419 | } |
| 420 | |
| 421 | set_key(key, params[1].value, params[1].length, salt); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 422 | AES_set_encrypt_key(key, MASTER_KEY_SIZE * 8, &aes_key); |
| 423 | memcpy(key, blob.value, MASTER_KEY_SIZE); |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 424 | blob.info = SALT_SIZE; |
| 425 | blob.length = MASTER_KEY_SIZE; |
| 426 | response = encrypt_blob(MASTER_KEY_FILE, &aes_key); |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 427 | } |
| 428 | |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 429 | if (response == NO_ERROR) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 430 | AES_set_encrypt_key(key, MASTER_KEY_SIZE * 8, &encryption_key); |
| 431 | AES_set_decrypt_key(key, MASTER_KEY_SIZE * 8, &decryption_key); |
| 432 | state = NO_ERROR; |
| 433 | retry = MAX_RETRY; |
| 434 | } |
Chia-chi Yeh | ae17a37 | 2010-10-01 01:27:34 +0800 | [diff] [blame] | 435 | return response; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 436 | } |
| 437 | |
| 438 | static int8_t lock() |
| 439 | { |
| 440 | memset(&encryption_key, 0, sizeof(encryption_key)); |
| 441 | memset(&decryption_key, 0, sizeof(decryption_key)); |
| 442 | state = LOCKED; |
Chia-chi Yeh | 2f3b2a5 | 2009-09-18 17:23:53 +0800 | [diff] [blame] | 443 | return NO_ERROR; |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 444 | } |
| 445 | |
| 446 | static int8_t unlock() |
| 447 | { |
| 448 | params[1].length = -1; |
| 449 | return password(); |
| 450 | } |
| 451 | |
| 452 | /* Here are the permissions, actions, users, and the main function. */ |
| 453 | |
| 454 | enum perm { |
| 455 | TEST = 1, |
| 456 | GET = 2, |
| 457 | INSERT = 4, |
| 458 | DELETE = 8, |
| 459 | EXIST = 16, |
Chia-chi Yeh | 1cdc2a4 | 2009-09-22 02:57:52 +0800 | [diff] [blame] | 460 | SAW = 32, |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 461 | RESET = 64, |
| 462 | PASSWORD = 128, |
| 463 | LOCK = 256, |
| 464 | UNLOCK = 512, |
| 465 | }; |
| 466 | |
| 467 | static struct action { |
| 468 | int8_t (*run)(); |
| 469 | int8_t code; |
| 470 | int8_t state; |
| 471 | uint32_t perm; |
| 472 | int lengths[MAX_PARAM]; |
| 473 | } actions[] = { |
| 474 | {test, 't', 0, TEST, {0}}, |
| 475 | {get, 'g', NO_ERROR, GET, {KEY_SIZE}}, |
| 476 | {insert, 'i', NO_ERROR, INSERT, {KEY_SIZE, VALUE_SIZE}}, |
Chia-chi Yeh | dd2a71e | 2009-09-20 10:15:46 +0800 | [diff] [blame] | 477 | {delete, 'd', 0, DELETE, {KEY_SIZE}}, |
| 478 | {exist, 'e', 0, EXIST, {KEY_SIZE}}, |
Chia-chi Yeh | 1cdc2a4 | 2009-09-22 02:57:52 +0800 | [diff] [blame] | 479 | {saw, 's', 0, SAW, {KEY_SIZE}}, |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 480 | {reset, 'r', 0, RESET, {0}}, |
| 481 | {password, 'p', 0, PASSWORD, {PASSWORD_SIZE, PASSWORD_SIZE}}, |
| 482 | {lock, 'l', NO_ERROR, LOCK, {0}}, |
| 483 | {unlock, 'u', LOCKED, UNLOCK, {PASSWORD_SIZE}}, |
| 484 | {NULL, 0 , 0, 0, {0}}, |
| 485 | }; |
| 486 | |
| 487 | static struct user { |
| 488 | uid_t uid; |
| 489 | uid_t euid; |
| 490 | uint32_t perms; |
| 491 | } users[] = { |
Chia-chi Yeh | e3bc023 | 2010-03-09 09:41:32 +0800 | [diff] [blame] | 492 | {AID_SYSTEM, ~0, ~GET}, |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 493 | {AID_VPN, AID_SYSTEM, GET}, |
| 494 | {AID_WIFI, AID_SYSTEM, GET}, |
Chia-chi Yeh | e3bc023 | 2010-03-09 09:41:32 +0800 | [diff] [blame] | 495 | {AID_ROOT, AID_SYSTEM, GET}, |
| 496 | {~0, ~0, TEST | GET | INSERT | DELETE | EXIST | SAW}, |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 497 | }; |
| 498 | |
| 499 | static int8_t process(int8_t code) { |
| 500 | struct user *user = users; |
| 501 | struct action *action = actions; |
| 502 | int i; |
| 503 | |
Chia-chi Yeh | e3bc023 | 2010-03-09 09:41:32 +0800 | [diff] [blame] | 504 | while (~user->uid && user->uid != uid) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 505 | ++user; |
| 506 | } |
| 507 | while (action->code && action->code != code) { |
| 508 | ++action; |
| 509 | } |
| 510 | if (!action->code) { |
| 511 | return UNDEFINED_ACTION; |
| 512 | } |
| 513 | if (!(action->perm & user->perms)) { |
| 514 | return PERMISSION_DENIED; |
| 515 | } |
| 516 | if (action->state && action->state != state) { |
| 517 | return state; |
| 518 | } |
Chia-chi Yeh | e3bc023 | 2010-03-09 09:41:32 +0800 | [diff] [blame] | 519 | if (~user->euid) { |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 520 | uid = user->euid; |
| 521 | } |
| 522 | for (i = 0; i < MAX_PARAM && action->lengths[i]; ++i) { |
| 523 | params[i].length = recv_message(params[i].value, action->lengths[i]); |
| 524 | if (params[i].length == -1) { |
| 525 | return PROTOCOL_ERROR; |
| 526 | } |
| 527 | } |
Chia-chi Yeh | dd2a71e | 2009-09-20 10:15:46 +0800 | [diff] [blame] | 528 | if (!recv_end_of_file()) { |
| 529 | return PROTOCOL_ERROR; |
| 530 | } |
Chia-chi Yeh | 4cff21f | 2009-09-18 10:15:37 +0800 | [diff] [blame] | 531 | return action->run(); |
| 532 | } |
| 533 | |
| 534 | #define RANDOM_DEVICE "/dev/urandom" |
| 535 | |
| 536 | int main(int argc, char **argv) |
| 537 | { |
| 538 | int control_socket = android_get_control_socket("keystore"); |
| 539 | if (argc < 2) { |
| 540 | LOGE("A directory must be specified!"); |
| 541 | return 1; |
| 542 | } |
| 543 | if (chdir(argv[1]) == -1) { |
| 544 | LOGE("chdir: %s: %s", argv[1], strerror(errno)); |
| 545 | return 1; |
| 546 | } |
| 547 | if ((the_entropy = open(RANDOM_DEVICE, O_RDONLY)) == -1) { |
| 548 | LOGE("open: %s: %s", RANDOM_DEVICE, strerror(errno)); |
| 549 | return 1; |
| 550 | } |
| 551 | if (listen(control_socket, 3) == -1) { |
| 552 | LOGE("listen: %s", strerror(errno)); |
| 553 | return 1; |
| 554 | } |
| 555 | |
| 556 | signal(SIGPIPE, SIG_IGN); |
| 557 | if (access(MASTER_KEY_FILE, R_OK) == 0) { |
| 558 | state = LOCKED; |
| 559 | } |
| 560 | |
| 561 | while ((the_socket = accept(control_socket, NULL, 0)) != -1) { |
| 562 | struct timeval tv = {.tv_sec = 3}; |
| 563 | struct ucred cred; |
| 564 | socklen_t size = sizeof(cred); |
| 565 | int8_t request; |
| 566 | |
| 567 | setsockopt(the_socket, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)); |
| 568 | setsockopt(the_socket, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)); |
| 569 | |
| 570 | if (getsockopt(the_socket, SOL_SOCKET, SO_PEERCRED, &cred, &size)) { |
| 571 | LOGW("getsockopt: %s", strerror(errno)); |
| 572 | } else if (recv_code(&request)) { |
| 573 | int8_t old_state = state; |
| 574 | int8_t response; |
| 575 | uid = cred.uid; |
| 576 | |
| 577 | if ((response = process(request)) > 0) { |
| 578 | send_code(response); |
| 579 | response = -response; |
| 580 | } |
| 581 | |
| 582 | LOGI("uid: %d action: %c -> %d state: %d -> %d retry: %d", |
| 583 | cred.uid, request, -response, old_state, state, retry); |
| 584 | } |
| 585 | close(the_socket); |
| 586 | } |
| 587 | LOGE("accept: %s", strerror(errno)); |
| 588 | return 1; |
| 589 | } |