1 /* 2 * Copyright (c) 2011 The FreeBSD Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 /* Based on: 27 * SHA512-based Unix crypt implementation. Released into the Public Domain by 28 * Ulrich Drepper <drepper@redhat.com>. */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/endian.h> 34 #include <sys/param.h> 35 36 #include <errno.h> 37 #include <limits.h> 38 #include <sha512.h> 39 #include <stdbool.h> 40 #include <stdint.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 45 #include "crypt.h" 46 47 /* Define our magic string to mark salt for SHA512 "encryption" replacement. */ 48 static const char sha512_salt_prefix[] = "$6$"; 49 50 /* Prefix for optional rounds specification. */ 51 static const char sha512_rounds_prefix[] = "rounds="; 52 53 /* Maximum salt string length. */ 54 #define SALT_LEN_MAX 16 55 /* Default number of rounds if not explicitly specified. */ 56 #define ROUNDS_DEFAULT 5000 57 /* Minimum number of rounds. */ 58 #define ROUNDS_MIN 1000 59 /* Maximum number of rounds. */ 60 #define ROUNDS_MAX 999999999 61 62 int 63 crypt_sha512(const char *key, const char *salt, char *buffer) 64 { 65 u_long srounds; 66 uint8_t alt_result[64], temp_result[64]; 67 SHA512_CTX ctx, alt_ctx; 68 size_t salt_len, key_len, cnt, rounds; 69 char *cp, *copied_key, *copied_salt, *p_bytes, *s_bytes, *endp; 70 const char *num; 71 bool rounds_custom; 72 73 copied_key = NULL; 74 copied_salt = NULL; 75 76 /* Default number of rounds. */ 77 rounds = ROUNDS_DEFAULT; 78 rounds_custom = false; 79 80 /* Find beginning of salt string. The prefix should normally always 81 * be present. Just in case it is not. */ 82 if (strncmp(sha512_salt_prefix, salt, sizeof(sha512_salt_prefix) - 1) == 0) 83 /* Skip salt prefix. */ 84 salt += sizeof(sha512_salt_prefix) - 1; 85 86 if (strncmp(salt, sha512_rounds_prefix, sizeof(sha512_rounds_prefix) - 1) 87 == 0) { 88 num = salt + sizeof(sha512_rounds_prefix) - 1; 89 srounds = strtoul(num, &endp, 10); 90 91 if (*endp == '$') { 92 salt = endp + 1; 93 rounds = MAX(ROUNDS_MIN, MIN(srounds, ROUNDS_MAX)); 94 rounds_custom = true; 95 } 96 } 97 98 salt_len = MIN(strcspn(salt, "$"), SALT_LEN_MAX); 99 key_len = strlen(key); 100 101 /* Prepare for the real work. */ 102 SHA512_Init(&ctx); 103 104 /* Add the key string. */ 105 SHA512_Update(&ctx, key, key_len); 106 107 /* The last part is the salt string. This must be at most 8 108 * characters and it ends at the first `$' character (for 109 * compatibility with existing implementations). */ 110 SHA512_Update(&ctx, salt, salt_len); 111 112 /* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The 113 * final result will be added to the first context. */ 114 SHA512_Init(&alt_ctx); 115 116 /* Add key. */ 117 SHA512_Update(&alt_ctx, key, key_len); 118 119 /* Add salt. */ 120 SHA512_Update(&alt_ctx, salt, salt_len); 121 122 /* Add key again. */ 123 SHA512_Update(&alt_ctx, key, key_len); 124 125 /* Now get result of this (64 bytes) and add it to the other context. */ 126 SHA512_Final(alt_result, &alt_ctx); 127 128 /* Add for any character in the key one byte of the alternate sum. */ 129 for (cnt = key_len; cnt > 64; cnt -= 64) 130 SHA512_Update(&ctx, alt_result, 64); 131 SHA512_Update(&ctx, alt_result, cnt); 132 133 /* Take the binary representation of the length of the key and for 134 * every 1 add the alternate sum, for every 0 the key. */ 135 for (cnt = key_len; cnt > 0; cnt >>= 1) 136 if ((cnt & 1) != 0) 137 SHA512_Update(&ctx, alt_result, 64); 138 else 139 SHA512_Update(&ctx, key, key_len); 140 141 /* Create intermediate result. */ 142 SHA512_Final(alt_result, &ctx); 143 144 /* Start computation of P byte sequence. */ 145 SHA512_Init(&alt_ctx); 146 147 /* For every character in the password add the entire password. */ 148 for (cnt = 0; cnt < key_len; ++cnt) 149 SHA512_Update(&alt_ctx, key, key_len); 150 151 /* Finish the digest. */ 152 SHA512_Final(temp_result, &alt_ctx); 153 154 /* Create byte sequence P. */ 155 cp = p_bytes = alloca(key_len); 156 for (cnt = key_len; cnt >= 64; cnt -= 64) { 157 memcpy(cp, temp_result, 64); 158 cp += 64; 159 } 160 memcpy(cp, temp_result, cnt); 161 162 /* Start computation of S byte sequence. */ 163 SHA512_Init(&alt_ctx); 164 165 /* For every character in the password add the entire password. */ 166 for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt) 167 SHA512_Update(&alt_ctx, salt, salt_len); 168 169 /* Finish the digest. */ 170 SHA512_Final(temp_result, &alt_ctx); 171 172 /* Create byte sequence S. */ 173 cp = s_bytes = alloca(salt_len); 174 for (cnt = salt_len; cnt >= 64; cnt -= 64) { 175 memcpy(cp, temp_result, 64); 176 cp += 64; 177 } 178 memcpy(cp, temp_result, cnt); 179 180 /* Repeatedly run the collected hash value through SHA512 to burn CPU 181 * cycles. */ 182 for (cnt = 0; cnt < rounds; ++cnt) { 183 /* New context. */ 184 SHA512_Init(&ctx); 185 186 /* Add key or last result. */ 187 if ((cnt & 1) != 0) 188 SHA512_Update(&ctx, p_bytes, key_len); 189 else 190 SHA512_Update(&ctx, alt_result, 64); 191 192 /* Add salt for numbers not divisible by 3. */ 193 if (cnt % 3 != 0) 194 SHA512_Update(&ctx, s_bytes, salt_len); 195 196 /* Add key for numbers not divisible by 7. */ 197 if (cnt % 7 != 0) 198 SHA512_Update(&ctx, p_bytes, key_len); 199 200 /* Add key or last result. */ 201 if ((cnt & 1) != 0) 202 SHA512_Update(&ctx, alt_result, 64); 203 else 204 SHA512_Update(&ctx, p_bytes, key_len); 205 206 /* Create intermediate result. */ 207 SHA512_Final(alt_result, &ctx); 208 } 209 210 /* Now we can construct the result string. It consists of three 211 * parts. */ 212 cp = stpcpy(buffer, sha512_salt_prefix); 213 214 if (rounds_custom) 215 cp += sprintf(cp, "%s%zu$", sha512_rounds_prefix, rounds); 216 217 cp = stpncpy(cp, salt, salt_len); 218 219 *cp++ = '$'; 220 221 b64_from_24bit(alt_result[0], alt_result[21], alt_result[42], 4, &cp); 222 b64_from_24bit(alt_result[22], alt_result[43], alt_result[1], 4, &cp); 223 b64_from_24bit(alt_result[44], alt_result[2], alt_result[23], 4, &cp); 224 b64_from_24bit(alt_result[3], alt_result[24], alt_result[45], 4, &cp); 225 b64_from_24bit(alt_result[25], alt_result[46], alt_result[4], 4, &cp); 226 b64_from_24bit(alt_result[47], alt_result[5], alt_result[26], 4, &cp); 227 b64_from_24bit(alt_result[6], alt_result[27], alt_result[48], 4, &cp); 228 b64_from_24bit(alt_result[28], alt_result[49], alt_result[7], 4, &cp); 229 b64_from_24bit(alt_result[50], alt_result[8], alt_result[29], 4, &cp); 230 b64_from_24bit(alt_result[9], alt_result[30], alt_result[51], 4, &cp); 231 b64_from_24bit(alt_result[31], alt_result[52], alt_result[10], 4, &cp); 232 b64_from_24bit(alt_result[53], alt_result[11], alt_result[32], 4, &cp); 233 b64_from_24bit(alt_result[12], alt_result[33], alt_result[54], 4, &cp); 234 b64_from_24bit(alt_result[34], alt_result[55], alt_result[13], 4, &cp); 235 b64_from_24bit(alt_result[56], alt_result[14], alt_result[35], 4, &cp); 236 b64_from_24bit(alt_result[15], alt_result[36], alt_result[57], 4, &cp); 237 b64_from_24bit(alt_result[37], alt_result[58], alt_result[16], 4, &cp); 238 b64_from_24bit(alt_result[59], alt_result[17], alt_result[38], 4, &cp); 239 b64_from_24bit(alt_result[18], alt_result[39], alt_result[60], 4, &cp); 240 b64_from_24bit(alt_result[40], alt_result[61], alt_result[19], 4, &cp); 241 b64_from_24bit(alt_result[62], alt_result[20], alt_result[41], 4, &cp); 242 b64_from_24bit(0, 0, alt_result[63], 2, &cp); 243 244 *cp = '\0'; /* Terminate the string. */ 245 246 /* Clear the buffer for the intermediate result so that people 247 * attaching to processes or reading core dumps cannot get any 248 * information. We do it in this way to clear correct_words[] inside 249 * the SHA512 implementation as well. */ 250 SHA512_Init(&ctx); 251 SHA512_Final(alt_result, &ctx); 252 memset(temp_result, '\0', sizeof(temp_result)); 253 memset(p_bytes, '\0', key_len); 254 memset(s_bytes, '\0', salt_len); 255 memset(&ctx, '\0', sizeof(ctx)); 256 memset(&alt_ctx, '\0', sizeof(alt_ctx)); 257 if (copied_key != NULL) 258 memset(copied_key, '\0', key_len); 259 if (copied_salt != NULL) 260 memset(copied_salt, '\0', salt_len); 261 262 return (0); 263 } 264 265 #ifdef TEST 266 267 static const struct { 268 const char *input; 269 const char result[64]; 270 } tests[] = 271 { 272 /* Test vectors from FIPS 180-2: appendix C.1. */ 273 { 274 "abc", 275 "\xdd\xaf\x35\xa1\x93\x61\x7a\xba\xcc\x41\x73\x49\xae\x20\x41\x31" 276 "\x12\xe6\xfa\x4e\x89\xa9\x7e\xa2\x0a\x9e\xee\xe6\x4b\x55\xd3\x9a" 277 "\x21\x92\x99\x2a\x27\x4f\xc1\xa8\x36\xba\x3c\x23\xa3\xfe\xeb\xbd" 278 "\x45\x4d\x44\x23\x64\x3c\xe8\x0e\x2a\x9a\xc9\x4f\xa5\x4c\xa4\x9f" 279 }, 280 /* Test vectors from FIPS 180-2: appendix C.2. */ 281 { 282 "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn" 283 "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu", 284 "\x8e\x95\x9b\x75\xda\xe3\x13\xda\x8c\xf4\xf7\x28\x14\xfc\x14\x3f" 285 "\x8f\x77\x79\xc6\xeb\x9f\x7f\xa1\x72\x99\xae\xad\xb6\x88\x90\x18" 286 "\x50\x1d\x28\x9e\x49\x00\xf7\xe4\x33\x1b\x99\xde\xc4\xb5\x43\x3a" 287 "\xc7\xd3\x29\xee\xb6\xdd\x26\x54\x5e\x96\xe5\x5b\x87\x4b\xe9\x09" 288 }, 289 /* Test vectors from the NESSIE project. */ 290 { 291 "", 292 "\xcf\x83\xe1\x35\x7e\xef\xb8\xbd\xf1\x54\x28\x50\xd6\x6d\x80\x07" 293 "\xd6\x20\xe4\x05\x0b\x57\x15\xdc\x83\xf4\xa9\x21\xd3\x6c\xe9\xce" 294 "\x47\xd0\xd1\x3c\x5d\x85\xf2\xb0\xff\x83\x18\xd2\x87\x7e\xec\x2f" 295 "\x63\xb9\x31\xbd\x47\x41\x7a\x81\xa5\x38\x32\x7a\xf9\x27\xda\x3e" 296 }, 297 { 298 "a", 299 "\x1f\x40\xfc\x92\xda\x24\x16\x94\x75\x09\x79\xee\x6c\xf5\x82\xf2" 300 "\xd5\xd7\xd2\x8e\x18\x33\x5d\xe0\x5a\xbc\x54\xd0\x56\x0e\x0f\x53" 301 "\x02\x86\x0c\x65\x2b\xf0\x8d\x56\x02\x52\xaa\x5e\x74\x21\x05\x46" 302 "\xf3\x69\xfb\xbb\xce\x8c\x12\xcf\xc7\x95\x7b\x26\x52\xfe\x9a\x75" 303 }, 304 { 305 "message digest", 306 "\x10\x7d\xbf\x38\x9d\x9e\x9f\x71\xa3\xa9\x5f\x6c\x05\x5b\x92\x51" 307 "\xbc\x52\x68\xc2\xbe\x16\xd6\xc1\x34\x92\xea\x45\xb0\x19\x9f\x33" 308 "\x09\xe1\x64\x55\xab\x1e\x96\x11\x8e\x8a\x90\x5d\x55\x97\xb7\x20" 309 "\x38\xdd\xb3\x72\xa8\x98\x26\x04\x6d\xe6\x66\x87\xbb\x42\x0e\x7c" 310 }, 311 { 312 "abcdefghijklmnopqrstuvwxyz", 313 "\x4d\xbf\xf8\x6c\xc2\xca\x1b\xae\x1e\x16\x46\x8a\x05\xcb\x98\x81" 314 "\xc9\x7f\x17\x53\xbc\xe3\x61\x90\x34\x89\x8f\xaa\x1a\xab\xe4\x29" 315 "\x95\x5a\x1b\xf8\xec\x48\x3d\x74\x21\xfe\x3c\x16\x46\x61\x3a\x59" 316 "\xed\x54\x41\xfb\x0f\x32\x13\x89\xf7\x7f\x48\xa8\x79\xc7\xb1\xf1" 317 }, 318 { 319 "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 320 "\x20\x4a\x8f\xc6\xdd\xa8\x2f\x0a\x0c\xed\x7b\xeb\x8e\x08\xa4\x16" 321 "\x57\xc1\x6e\xf4\x68\xb2\x28\xa8\x27\x9b\xe3\x31\xa7\x03\xc3\x35" 322 "\x96\xfd\x15\xc1\x3b\x1b\x07\xf9\xaa\x1d\x3b\xea\x57\x78\x9c\xa0" 323 "\x31\xad\x85\xc7\xa7\x1d\xd7\x03\x54\xec\x63\x12\x38\xca\x34\x45" 324 }, 325 { 326 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 327 "\x1e\x07\xbe\x23\xc2\x6a\x86\xea\x37\xea\x81\x0c\x8e\xc7\x80\x93" 328 "\x52\x51\x5a\x97\x0e\x92\x53\xc2\x6f\x53\x6c\xfc\x7a\x99\x96\xc4" 329 "\x5c\x83\x70\x58\x3e\x0a\x78\xfa\x4a\x90\x04\x1d\x71\xa4\xce\xab" 330 "\x74\x23\xf1\x9c\x71\xb9\xd5\xa3\xe0\x12\x49\xf0\xbe\xbd\x58\x94" 331 }, 332 { 333 "123456789012345678901234567890123456789012345678901234567890" 334 "12345678901234567890", 335 "\x72\xec\x1e\xf1\x12\x4a\x45\xb0\x47\xe8\xb7\xc7\x5a\x93\x21\x95" 336 "\x13\x5b\xb6\x1d\xe2\x4e\xc0\xd1\x91\x40\x42\x24\x6e\x0a\xec\x3a" 337 "\x23\x54\xe0\x93\xd7\x6f\x30\x48\xb4\x56\x76\x43\x46\x90\x0c\xb1" 338 "\x30\xd2\xa4\xfd\x5d\xd1\x6a\xbb\x5e\x30\xbc\xb8\x50\xde\xe8\x43" 339 } 340 }; 341 342 #define ntests (sizeof (tests) / sizeof (tests[0])) 343 344 static const struct { 345 const char *salt; 346 const char *input; 347 const char *expected; 348 } tests2[] = 349 { 350 { 351 "$6$saltstring", "Hello world!", 352 "$6$saltstring$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJu" 353 "esI68u4OTLiBFdcbYEdFCoEOfaS35inz1" 354 }, 355 { 356 "$6$rounds=10000$saltstringsaltstring", "Hello world!", 357 "$6$rounds=10000$saltstringsaltst$OW1/O6BYHV6BcXZu8QVeXbDWra3Oeqh0sb" 358 "HbbMCVNSnCM/UrjmM0Dp8vOuZeHBy/YTBmSK6H9qs/y3RnOaw5v." 359 }, 360 { 361 "$6$rounds=5000$toolongsaltstring", "This is just a test", 362 "$6$rounds=5000$toolongsaltstrin$lQ8jolhgVRVhY4b5pZKaysCLi0QBxGoNeKQ" 363 "zQ3glMhwllF7oGDZxUhx1yxdYcz/e1JSbq3y6JMxxl8audkUEm0" 364 }, 365 { 366 "$6$rounds=1400$anotherlongsaltstring", 367 "a very much longer text to encrypt. This one even stretches over more" 368 "than one line.", 369 "$6$rounds=1400$anotherlongsalts$POfYwTEok97VWcjxIiSOjiykti.o/pQs.wP" 370 "vMxQ6Fm7I6IoYN3CmLs66x9t0oSwbtEW7o7UmJEiDwGqd8p4ur1" 371 }, 372 { 373 "$6$rounds=77777$short", 374 "we have a short salt string but not a short password", 375 "$6$rounds=77777$short$WuQyW2YR.hBNpjjRhpYD/ifIw05xdfeEyQoMxIXbkvr0g" 376 "ge1a1x3yRULJ5CCaUeOxFmtlcGZelFl5CxtgfiAc0" 377 }, 378 { 379 "$6$rounds=123456$asaltof16chars..", "a short string", 380 "$6$rounds=123456$asaltof16chars..$BtCwjqMJGx5hrJhZywWvt0RLE8uZ4oPwc" 381 "elCjmw2kSYu.Ec6ycULevoBK25fs2xXgMNrCzIMVcgEJAstJeonj1" 382 }, 383 { 384 "$6$rounds=10$roundstoolow", "the minimum number is still observed", 385 "$6$rounds=1000$roundstoolow$kUMsbe306n21p9R.FRkW3IGn.S9NPN0x50YhH1x" 386 "hLsPuWGsUSklZt58jaTfF4ZEQpyUNGc0dqbpBYYBaHHrsX." 387 }, 388 }; 389 390 #define ntests2 (sizeof (tests2) / sizeof (tests2[0])) 391 392 int 393 main(void) 394 { 395 SHA512_CTX ctx; 396 uint8_t sum[64]; 397 int result = 0; 398 int i, cnt; 399 400 for (cnt = 0; cnt < (int)ntests; ++cnt) { 401 SHA512_Init(&ctx); 402 SHA512_Update(&ctx, tests[cnt].input, strlen(tests[cnt].input)); 403 SHA512_Final(sum, &ctx); 404 if (memcmp(tests[cnt].result, sum, 64) != 0) { 405 printf("test %d run %d failed\n", cnt, 1); 406 result = 1; 407 } 408 409 SHA512_Init(&ctx); 410 for (i = 0; tests[cnt].input[i] != '\0'; ++i) 411 SHA512_Update(&ctx, &tests[cnt].input[i], 1); 412 SHA512_Final(sum, &ctx); 413 if (memcmp(tests[cnt].result, sum, 64) != 0) { 414 printf("test %d run %d failed\n", cnt, 2); 415 result = 1; 416 } 417 } 418 419 /* Test vector from FIPS 180-2: appendix C.3. */ 420 char buf[1000]; 421 422 memset(buf, 'a', sizeof(buf)); 423 SHA512_Init(&ctx); 424 for (i = 0; i < 1000; ++i) 425 SHA512_Update(&ctx, buf, sizeof(buf)); 426 SHA512_Final(sum, &ctx); 427 static const char expected[64] = 428 "\xe7\x18\x48\x3d\x0c\xe7\x69\x64\x4e\x2e\x42\xc7\xbc\x15\xb4\x63" 429 "\x8e\x1f\x98\xb1\x3b\x20\x44\x28\x56\x32\xa8\x03\xaf\xa9\x73\xeb" 430 "\xde\x0f\xf2\x44\x87\x7e\xa6\x0a\x4c\xb0\x43\x2c\xe5\x77\xc3\x1b" 431 "\xeb\x00\x9c\x5c\x2c\x49\xaa\x2e\x4e\xad\xb2\x17\xad\x8c\xc0\x9b"; 432 433 if (memcmp(expected, sum, 64) != 0) { 434 printf("test %d failed\n", cnt); 435 result = 1; 436 } 437 438 for (cnt = 0; cnt < ntests2; ++cnt) { 439 char *cp = crypt_sha512(tests2[cnt].input, tests2[cnt].salt); 440 441 if (strcmp(cp, tests2[cnt].expected) != 0) { 442 printf("test %d: expected \"%s\", got \"%s\"\n", 443 cnt, tests2[cnt].expected, cp); 444 result = 1; 445 } 446 } 447 448 if (result == 0) 449 puts("all tests OK"); 450 451 return result; 452 } 453 454 #endif /* TEST */ 455