Benoit Goby | d5fcafa | 2012-04-12 12:23:49 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 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 | |
| 19 | #ifdef _WIN32 |
| 20 | # define WIN32_LEAN_AND_MEAN |
| 21 | # include "windows.h" |
| 22 | # include "shlobj.h" |
| 23 | #else |
| 24 | # include <sys/types.h> |
| 25 | # include <sys/stat.h> |
| 26 | # include <unistd.h> |
| 27 | #endif |
| 28 | #include <string.h> |
| 29 | |
| 30 | #include "sysdeps.h" |
| 31 | #include "adb.h" |
| 32 | #include "adb_auth.h" |
| 33 | |
| 34 | /* HACK: we need the RSAPublicKey struct |
| 35 | * but RSA_verify conflits with openssl */ |
| 36 | #define RSA_verify RSA_verify_mincrypt |
| 37 | #include "mincrypt/rsa.h" |
| 38 | #undef RSA_verify |
| 39 | |
| 40 | #include <cutils/list.h> |
| 41 | |
| 42 | #include <openssl/evp.h> |
| 43 | #include <openssl/objects.h> |
| 44 | #include <openssl/pem.h> |
| 45 | #include <openssl/rsa.h> |
| 46 | #include <openssl/sha.h> |
| 47 | |
| 48 | #define TRACE_TAG TRACE_AUTH |
| 49 | |
| 50 | #define ANDROID_PATH ".android" |
| 51 | #define ADB_KEY_FILE "adb_key" |
| 52 | |
| 53 | |
| 54 | struct adb_private_key { |
| 55 | struct listnode node; |
| 56 | RSA *rsa; |
| 57 | }; |
| 58 | |
| 59 | static struct listnode key_list; |
| 60 | |
| 61 | |
| 62 | /* Convert OpenSSL RSA private key to android pre-computed RSAPublicKey format */ |
| 63 | static int RSA_to_RSAPublicKey(RSA *rsa, RSAPublicKey *pkey) |
| 64 | { |
| 65 | int ret = 1; |
| 66 | unsigned int i; |
| 67 | |
| 68 | BN_CTX* ctx = BN_CTX_new(); |
| 69 | BIGNUM* r32 = BN_new(); |
| 70 | BIGNUM* rr = BN_new(); |
| 71 | BIGNUM* r = BN_new(); |
| 72 | BIGNUM* rem = BN_new(); |
| 73 | BIGNUM* n = BN_new(); |
| 74 | BIGNUM* n0inv = BN_new(); |
| 75 | |
| 76 | if (RSA_size(rsa) != RSANUMBYTES) { |
| 77 | ret = 0; |
| 78 | goto out; |
| 79 | } |
| 80 | |
| 81 | BN_set_bit(r32, 32); |
| 82 | BN_copy(n, rsa->n); |
| 83 | BN_set_bit(r, RSANUMWORDS * 32); |
| 84 | BN_mod_sqr(rr, r, n, ctx); |
| 85 | BN_div(NULL, rem, n, r32, ctx); |
| 86 | BN_mod_inverse(n0inv, rem, r32, ctx); |
| 87 | |
| 88 | pkey->len = RSANUMWORDS; |
| 89 | pkey->n0inv = 0 - BN_get_word(n0inv); |
| 90 | for (i = 0; i < RSANUMWORDS; i++) { |
| 91 | BN_div(rr, rem, rr, r32, ctx); |
| 92 | pkey->rr[i] = BN_get_word(rem); |
| 93 | BN_div(n, rem, n, r32, ctx); |
| 94 | pkey->n[i] = BN_get_word(rem); |
| 95 | } |
| 96 | pkey->exponent = BN_get_word(rsa->e); |
| 97 | |
| 98 | out: |
| 99 | BN_free(n0inv); |
| 100 | BN_free(n); |
| 101 | BN_free(rem); |
| 102 | BN_free(r); |
| 103 | BN_free(rr); |
| 104 | BN_free(r32); |
| 105 | BN_CTX_free(ctx); |
| 106 | |
| 107 | return ret; |
| 108 | } |
| 109 | |
| 110 | static void get_user_info(char *buf, size_t len) |
| 111 | { |
| 112 | char hostname[1024], username[1024]; |
| 113 | int ret; |
| 114 | |
| 115 | #ifndef _WIN32 |
| 116 | ret = gethostname(hostname, sizeof(hostname)); |
| 117 | if (ret < 0) |
| 118 | #endif |
| 119 | strcpy(hostname, "unknown"); |
| 120 | |
| 121 | #if !defined _WIN32 && !defined ADB_HOST_ON_TARGET |
| 122 | ret = getlogin_r(username, sizeof(username)); |
| 123 | if (ret < 0) |
| 124 | #endif |
| 125 | strcpy(username, "unknown"); |
| 126 | |
| 127 | ret = snprintf(buf, len, " %s@%s", username, hostname); |
| 128 | if (ret >= (signed)len) |
| 129 | buf[len - 1] = '\0'; |
| 130 | } |
| 131 | |
| 132 | static int write_public_keyfile(RSA *private_key, const char *private_key_path) |
| 133 | { |
| 134 | RSAPublicKey pkey; |
| 135 | BIO *bio, *b64, *bfile; |
| 136 | char path[PATH_MAX], info[MAX_PAYLOAD]; |
| 137 | int ret; |
| 138 | |
| 139 | ret = snprintf(path, sizeof(path), "%s.pub", private_key_path); |
| 140 | if (ret >= (signed)sizeof(path)) |
| 141 | return 0; |
| 142 | |
| 143 | ret = RSA_to_RSAPublicKey(private_key, &pkey); |
| 144 | if (!ret) { |
| 145 | D("Failed to convert to publickey\n"); |
| 146 | return 0; |
| 147 | } |
| 148 | |
| 149 | bfile = BIO_new_file(path, "w"); |
| 150 | if (!bfile) { |
| 151 | D("Failed to open '%s'\n", path); |
| 152 | return 0; |
| 153 | } |
| 154 | |
| 155 | D("Writing public key to '%s'\n", path); |
| 156 | |
| 157 | b64 = BIO_new(BIO_f_base64()); |
| 158 | BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL); |
| 159 | |
| 160 | bio = BIO_push(b64, bfile); |
| 161 | BIO_write(bio, &pkey, sizeof(pkey)); |
| 162 | BIO_flush(bio); |
| 163 | BIO_pop(b64); |
| 164 | BIO_free(b64); |
| 165 | |
| 166 | get_user_info(info, sizeof(info)); |
| 167 | BIO_write(bfile, info, strlen(info)); |
| 168 | BIO_flush(bfile); |
| 169 | BIO_free_all(bfile); |
| 170 | |
| 171 | return 1; |
| 172 | } |
| 173 | |
| 174 | static int generate_key(const char *file) |
| 175 | { |
| 176 | EVP_PKEY* pkey = EVP_PKEY_new(); |
| 177 | BIGNUM* exponent = BN_new(); |
| 178 | RSA* rsa = RSA_new(); |
| 179 | FILE *f = NULL; |
| 180 | int ret = 0; |
| 181 | |
| 182 | D("generate_key '%s'\n", file); |
| 183 | |
| 184 | if (!pkey || !exponent || !rsa) { |
| 185 | D("Failed to allocate key\n"); |
| 186 | goto out; |
| 187 | } |
| 188 | |
| 189 | BN_set_word(exponent, RSA_F4); |
| 190 | RSA_generate_key_ex(rsa, 2048, exponent, NULL); |
| 191 | EVP_PKEY_set1_RSA(pkey, rsa); |
| 192 | |
| 193 | f = fopen(file, "w"); |
| 194 | if (!f) { |
| 195 | D("Failed to open '%s'\n", file); |
| 196 | goto out; |
| 197 | } |
| 198 | |
| 199 | if (!PEM_write_PrivateKey(f, pkey, NULL, NULL, 0, NULL, NULL)) { |
| 200 | D("Failed to write key\n"); |
| 201 | goto out; |
| 202 | } |
| 203 | |
| 204 | if (!write_public_keyfile(rsa, file)) { |
| 205 | D("Failed to write public key\n"); |
| 206 | goto out; |
| 207 | } |
| 208 | |
| 209 | ret = 1; |
| 210 | |
| 211 | out: |
| 212 | if (f) |
| 213 | fclose(f); |
| 214 | EVP_PKEY_free(pkey); |
| 215 | RSA_free(rsa); |
| 216 | BN_free(exponent); |
| 217 | return ret; |
| 218 | } |
| 219 | |
| 220 | static int read_key(const char *file, struct listnode *list) |
| 221 | { |
| 222 | struct adb_private_key *key; |
| 223 | FILE *f; |
| 224 | |
| 225 | D("read_key '%s'\n", file); |
| 226 | |
| 227 | f = fopen(file, "r"); |
| 228 | if (!f) { |
| 229 | D("Failed to open '%s'\n", file); |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | key = malloc(sizeof(*key)); |
| 234 | if (!key) { |
| 235 | D("Failed to alloc key\n"); |
| 236 | fclose(f); |
| 237 | return 0; |
| 238 | } |
| 239 | key->rsa = RSA_new(); |
| 240 | |
| 241 | if (!PEM_read_RSAPrivateKey(f, &key->rsa, NULL, NULL)) { |
| 242 | D("Failed to read key\n"); |
| 243 | fclose(f); |
| 244 | RSA_free(key->rsa); |
| 245 | free(key); |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | fclose(f); |
| 250 | list_add_tail(list, &key->node); |
| 251 | return 1; |
| 252 | } |
| 253 | |
| 254 | static int get_user_keyfilepath(char *filename, size_t len) |
| 255 | { |
| 256 | const char *format, *home; |
| 257 | char android_dir[PATH_MAX]; |
| 258 | struct stat buf; |
| 259 | #ifdef _WIN32 |
| 260 | char path[PATH_MAX]; |
| 261 | home = getenv("ANDROID_SDK_HOME"); |
| 262 | if (!home) { |
| 263 | SHGetFolderPath(NULL, CSIDL_PROFILE, NULL, 0, path); |
| 264 | home = path; |
| 265 | } |
| 266 | format = "%s\\%s"; |
| 267 | #else |
| 268 | home = getenv("HOME"); |
| 269 | if (!home) |
| 270 | return -1; |
| 271 | format = "%s/%s"; |
| 272 | #endif |
| 273 | |
| 274 | D("home '%s'\n", home); |
| 275 | |
| 276 | if (snprintf(android_dir, sizeof(android_dir), format, home, |
| 277 | ANDROID_PATH) >= (int)sizeof(android_dir)) |
| 278 | return -1; |
| 279 | |
| 280 | if (stat(android_dir, &buf)) { |
| 281 | if (adb_mkdir(android_dir, 0750) < 0) { |
| 282 | D("Cannot mkdir '%s'", android_dir); |
| 283 | return -1; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | return snprintf(filename, len, format, android_dir, ADB_KEY_FILE); |
| 288 | } |
| 289 | |
| 290 | static int get_user_key(struct listnode *list) |
| 291 | { |
| 292 | struct stat buf; |
| 293 | char path[PATH_MAX]; |
| 294 | int ret; |
| 295 | |
| 296 | ret = get_user_keyfilepath(path, sizeof(path)); |
| 297 | if (ret < 0 || ret >= (signed)sizeof(path)) { |
| 298 | D("Error getting user key filename"); |
| 299 | return 0; |
| 300 | } |
| 301 | |
| 302 | D("user key '%s'\n", path); |
| 303 | |
| 304 | if (stat(path, &buf) == -1) { |
| 305 | if (!generate_key(path)) { |
| 306 | D("Failed to generate new key\n"); |
| 307 | return 0; |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | return read_key(path, list); |
| 312 | } |
| 313 | |
| 314 | static void get_vendor_keys(struct listnode *list) |
| 315 | { |
| 316 | const char *adb_keys_path; |
| 317 | char keys_path[MAX_PAYLOAD]; |
| 318 | char *path; |
| 319 | char *save; |
| 320 | struct stat buf; |
| 321 | |
| 322 | adb_keys_path = getenv("ADB_VENDOR_KEYS"); |
| 323 | if (!adb_keys_path) |
| 324 | return; |
| 325 | strncpy(keys_path, adb_keys_path, sizeof(keys_path)); |
| 326 | |
| 327 | path = adb_strtok_r(keys_path, ENV_PATH_SEPARATOR_STR, &save); |
| 328 | while (path) { |
| 329 | D("Reading: '%s'\n", path); |
| 330 | |
| 331 | if (stat(path, &buf)) |
| 332 | D("Can't read '%s'\n", path); |
| 333 | else if (!read_key(path, list)) |
| 334 | D("Failed to read '%s'\n", path); |
| 335 | |
| 336 | path = adb_strtok_r(NULL, ENV_PATH_SEPARATOR_STR, &save); |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | int adb_auth_sign(void *node, void *token, size_t token_size, void *sig) |
| 341 | { |
| 342 | unsigned int len; |
| 343 | struct adb_private_key *key = node_to_item(node, struct adb_private_key, node); |
| 344 | |
| 345 | if (!RSA_sign(NID_sha1, token, token_size, sig, &len, key->rsa)) { |
| 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | D("adb_auth_sign len=%d\n", len); |
| 350 | return (int)len; |
| 351 | } |
| 352 | |
| 353 | void *adb_auth_nextkey(void *current) |
| 354 | { |
| 355 | struct listnode *item; |
| 356 | |
| 357 | if (list_empty(&key_list)) |
| 358 | return NULL; |
| 359 | |
| 360 | if (!current) |
| 361 | return list_head(&key_list); |
| 362 | |
| 363 | list_for_each(item, &key_list) { |
| 364 | if (item == current) { |
| 365 | /* current is the last item, we tried all the keys */ |
| 366 | if (item->next == &key_list) |
| 367 | return NULL; |
| 368 | return item->next; |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | return NULL; |
| 373 | } |
| 374 | |
| 375 | int adb_auth_get_userkey(unsigned char *data, size_t len) |
| 376 | { |
| 377 | char path[PATH_MAX]; |
| 378 | char *file; |
| 379 | int ret; |
| 380 | |
| 381 | ret = get_user_keyfilepath(path, sizeof(path) - 4); |
| 382 | if (ret < 0 || ret >= (signed)(sizeof(path) - 4)) { |
| 383 | D("Error getting user key filename"); |
| 384 | return 0; |
| 385 | } |
| 386 | strcat(path, ".pub"); |
| 387 | |
| 388 | file = load_file(path, (unsigned*)&ret); |
| 389 | if (!file) { |
| 390 | D("Can't load '%s'\n", path); |
| 391 | return 0; |
| 392 | } |
| 393 | |
| 394 | if (len < (size_t)(ret + 1)) { |
| 395 | D("%s: Content too large ret=%d\n", path, ret); |
| 396 | return 0; |
| 397 | } |
| 398 | |
| 399 | memcpy(data, file, ret); |
| 400 | data[ret] = '\0'; |
| 401 | |
| 402 | return ret + 1; |
| 403 | } |
| 404 | |
| 405 | void adb_auth_init(void) |
| 406 | { |
| 407 | int ret; |
| 408 | |
| 409 | D("adb_auth_init\n"); |
| 410 | |
| 411 | list_init(&key_list); |
| 412 | |
| 413 | ret = get_user_key(&key_list); |
| 414 | if (!ret) { |
| 415 | D("Failed to get user key\n"); |
| 416 | return; |
| 417 | } |
| 418 | |
| 419 | get_vendor_keys(&key_list); |
| 420 | } |