1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011 The FreeBSD Project. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* Based on: 29 * SHA512-based Unix crypt implementation. Released into the Public Domain by 30 * Ulrich Drepper <drepper@redhat.com>. */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/endian.h> 36 #include <sys/param.h> 37 38 #include <errno.h> 39 #include <limits.h> 40 #include <sha512.h> 41 #include <stdbool.h> 42 #include <stdint.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include "crypt.h" 48 49 /* Define our magic string to mark salt for SHA512 "encryption" replacement. */ 50 static const char sha512_salt_prefix[] = "$6$"; 51 52 /* Prefix for optional rounds specification. */ 53 static const char sha512_rounds_prefix[] = "rounds="; 54 55 /* Maximum salt string length. */ 56 #define SALT_LEN_MAX 16 57 /* Default number of rounds if not explicitly specified. */ 58 #define ROUNDS_DEFAULT 5000 59 /* Minimum number of rounds. */ 60 #define ROUNDS_MIN 1000 61 /* Maximum number of rounds. */ 62 #define ROUNDS_MAX 999999999 63 64 int 65 crypt_sha512(const char *key, const char *salt, char *buffer) 66 { 67 u_long srounds; 68 uint8_t alt_result[64], temp_result[64]; 69 SHA512_CTX ctx, alt_ctx; 70 size_t salt_len, key_len, cnt, rounds; 71 char *cp, *copied_key, *copied_salt, *p_bytes, *s_bytes, *endp; 72 const char *num; 73 bool rounds_custom; 74 75 copied_key = NULL; 76 copied_salt = NULL; 77 78 /* Default number of rounds. */ 79 rounds = ROUNDS_DEFAULT; 80 rounds_custom = false; 81 82 /* Find beginning of salt string. The prefix should normally always 83 * be present. Just in case it is not. */ 84 if (strncmp(sha512_salt_prefix, salt, sizeof(sha512_salt_prefix) - 1) == 0) 85 /* Skip salt prefix. */ 86 salt += sizeof(sha512_salt_prefix) - 1; 87 88 if (strncmp(salt, sha512_rounds_prefix, sizeof(sha512_rounds_prefix) - 1) 89 == 0) { 90 num = salt + sizeof(sha512_rounds_prefix) - 1; 91 srounds = strtoul(num, &endp, 10); 92 93 if (*endp == '$') { 94 salt = endp + 1; 95 rounds = MAX(ROUNDS_MIN, MIN(srounds, ROUNDS_MAX)); 96 rounds_custom = true; 97 } 98 } 99 100 salt_len = MIN(strcspn(salt, "$"), SALT_LEN_MAX); 101 key_len = strlen(key); 102 103 /* Prepare for the real work. */ 104 SHA512_Init(&ctx); 105 106 /* Add the key string. */ 107 SHA512_Update(&ctx, key, key_len); 108 109 /* The last part is the salt string. This must be at most 8 110 * characters and it ends at the first `$' character (for 111 * compatibility with existing implementations). */ 112 SHA512_Update(&ctx, salt, salt_len); 113 114 /* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The 115 * final result will be added to the first context. */ 116 SHA512_Init(&alt_ctx); 117 118 /* Add key. */ 119 SHA512_Update(&alt_ctx, key, key_len); 120 121 /* Add salt. */ 122 SHA512_Update(&alt_ctx, salt, salt_len); 123 124 /* Add key again. */ 125 SHA512_Update(&alt_ctx, key, key_len); 126 127 /* Now get result of this (64 bytes) and add it to the other context. */ 128 SHA512_Final(alt_result, &alt_ctx); 129 130 /* Add for any character in the key one byte of the alternate sum. */ 131 for (cnt = key_len; cnt > 64; cnt -= 64) 132 SHA512_Update(&ctx, alt_result, 64); 133 SHA512_Update(&ctx, alt_result, cnt); 134 135 /* Take the binary representation of the length of the key and for 136 * every 1 add the alternate sum, for every 0 the key. */ 137 for (cnt = key_len; cnt > 0; cnt >>= 1) 138 if ((cnt & 1) != 0) 139 SHA512_Update(&ctx, alt_result, 64); 140 else 141 SHA512_Update(&ctx, key, key_len); 142 143 /* Create intermediate result. */ 144 SHA512_Final(alt_result, &ctx); 145 146 /* Start computation of P byte sequence. */ 147 SHA512_Init(&alt_ctx); 148 149 /* For every character in the password add the entire password. */ 150 for (cnt = 0; cnt < key_len; ++cnt) 151 SHA512_Update(&alt_ctx, key, key_len); 152 153 /* Finish the digest. */ 154 SHA512_Final(temp_result, &alt_ctx); 155 156 /* Create byte sequence P. */ 157 cp = p_bytes = alloca(key_len); 158 for (cnt = key_len; cnt >= 64; cnt -= 64) { 159 memcpy(cp, temp_result, 64); 160 cp += 64; 161 } 162 memcpy(cp, temp_result, cnt); 163 164 /* Start computation of S byte sequence. */ 165 SHA512_Init(&alt_ctx); 166 167 /* For every character in the password add the entire password. */ 168 for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt) 169 SHA512_Update(&alt_ctx, salt, salt_len); 170 171 /* Finish the digest. */ 172 SHA512_Final(temp_result, &alt_ctx); 173 174 /* Create byte sequence S. */ 175 cp = s_bytes = alloca(salt_len); 176 for (cnt = salt_len; cnt >= 64; cnt -= 64) { 177 memcpy(cp, temp_result, 64); 178 cp += 64; 179 } 180 memcpy(cp, temp_result, cnt); 181 182 /* Repeatedly run the collected hash value through SHA512 to burn CPU 183 * cycles. */ 184 for (cnt = 0; cnt < rounds; ++cnt) { 185 /* New context. */ 186 SHA512_Init(&ctx); 187 188 /* Add key or last result. */ 189 if ((cnt & 1) != 0) 190 SHA512_Update(&ctx, p_bytes, key_len); 191 else 192 SHA512_Update(&ctx, alt_result, 64); 193 194 /* Add salt for numbers not divisible by 3. */ 195 if (cnt % 3 != 0) 196 SHA512_Update(&ctx, s_bytes, salt_len); 197 198 /* Add key for numbers not divisible by 7. */ 199 if (cnt % 7 != 0) 200 SHA512_Update(&ctx, p_bytes, key_len); 201 202 /* Add key or last result. */ 203 if ((cnt & 1) != 0) 204 SHA512_Update(&ctx, alt_result, 64); 205 else 206 SHA512_Update(&ctx, p_bytes, key_len); 207 208 /* Create intermediate result. */ 209 SHA512_Final(alt_result, &ctx); 210 } 211 212 /* Now we can construct the result string. It consists of three 213 * parts. */ 214 cp = stpcpy(buffer, sha512_salt_prefix); 215 216 if (rounds_custom) 217 cp += sprintf(cp, "%s%zu$", sha512_rounds_prefix, rounds); 218 219 cp = stpncpy(cp, salt, salt_len); 220 221 *cp++ = '$'; 222 223 b64_from_24bit(alt_result[0], alt_result[21], alt_result[42], 4, &cp); 224 b64_from_24bit(alt_result[22], alt_result[43], alt_result[1], 4, &cp); 225 b64_from_24bit(alt_result[44], alt_result[2], alt_result[23], 4, &cp); 226 b64_from_24bit(alt_result[3], alt_result[24], alt_result[45], 4, &cp); 227 b64_from_24bit(alt_result[25], alt_result[46], alt_result[4], 4, &cp); 228 b64_from_24bit(alt_result[47], alt_result[5], alt_result[26], 4, &cp); 229 b64_from_24bit(alt_result[6], alt_result[27], alt_result[48], 4, &cp); 230 b64_from_24bit(alt_result[28], alt_result[49], alt_result[7], 4, &cp); 231 b64_from_24bit(alt_result[50], alt_result[8], alt_result[29], 4, &cp); 232 b64_from_24bit(alt_result[9], alt_result[30], alt_result[51], 4, &cp); 233 b64_from_24bit(alt_result[31], alt_result[52], alt_result[10], 4, &cp); 234 b64_from_24bit(alt_result[53], alt_result[11], alt_result[32], 4, &cp); 235 b64_from_24bit(alt_result[12], alt_result[33], alt_result[54], 4, &cp); 236 b64_from_24bit(alt_result[34], alt_result[55], alt_result[13], 4, &cp); 237 b64_from_24bit(alt_result[56], alt_result[14], alt_result[35], 4, &cp); 238 b64_from_24bit(alt_result[15], alt_result[36], alt_result[57], 4, &cp); 239 b64_from_24bit(alt_result[37], alt_result[58], alt_result[16], 4, &cp); 240 b64_from_24bit(alt_result[59], alt_result[17], alt_result[38], 4, &cp); 241 b64_from_24bit(alt_result[18], alt_result[39], alt_result[60], 4, &cp); 242 b64_from_24bit(alt_result[40], alt_result[61], alt_result[19], 4, &cp); 243 b64_from_24bit(alt_result[62], alt_result[20], alt_result[41], 4, &cp); 244 b64_from_24bit(0, 0, alt_result[63], 2, &cp); 245 246 *cp = '\0'; /* Terminate the string. */ 247 248 /* Clear the buffer for the intermediate result so that people 249 * attaching to processes or reading core dumps cannot get any 250 * information. We do it in this way to clear correct_words[] inside 251 * the SHA512 implementation as well. */ 252 SHA512_Init(&ctx); 253 SHA512_Final(alt_result, &ctx); 254 memset(temp_result, '\0', sizeof(temp_result)); 255 memset(p_bytes, '\0', key_len); 256 memset(s_bytes, '\0', salt_len); 257 memset(&ctx, '\0', sizeof(ctx)); 258 memset(&alt_ctx, '\0', sizeof(alt_ctx)); 259 if (copied_key != NULL) 260 memset(copied_key, '\0', key_len); 261 if (copied_salt != NULL) 262 memset(copied_salt, '\0', salt_len); 263 264 return (0); 265 } 266 267 #ifdef TEST 268 269 static const struct { 270 const char *input; 271 const char result[64]; 272 } tests[] = 273 { 274 /* Test vectors from FIPS 180-2: appendix C.1. */ 275 { 276 "abc", 277 "\xdd\xaf\x35\xa1\x93\x61\x7a\xba\xcc\x41\x73\x49\xae\x20\x41\x31" 278 "\x12\xe6\xfa\x4e\x89\xa9\x7e\xa2\x0a\x9e\xee\xe6\x4b\x55\xd3\x9a" 279 "\x21\x92\x99\x2a\x27\x4f\xc1\xa8\x36\xba\x3c\x23\xa3\xfe\xeb\xbd" 280 "\x45\x4d\x44\x23\x64\x3c\xe8\x0e\x2a\x9a\xc9\x4f\xa5\x4c\xa4\x9f" 281 }, 282 /* Test vectors from FIPS 180-2: appendix C.2. */ 283 { 284 "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn" 285 "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu", 286 "\x8e\x95\x9b\x75\xda\xe3\x13\xda\x8c\xf4\xf7\x28\x14\xfc\x14\x3f" 287 "\x8f\x77\x79\xc6\xeb\x9f\x7f\xa1\x72\x99\xae\xad\xb6\x88\x90\x18" 288 "\x50\x1d\x28\x9e\x49\x00\xf7\xe4\x33\x1b\x99\xde\xc4\xb5\x43\x3a" 289 "\xc7\xd3\x29\xee\xb6\xdd\x26\x54\x5e\x96\xe5\x5b\x87\x4b\xe9\x09" 290 }, 291 /* Test vectors from the NESSIE project. */ 292 { 293 "", 294 "\xcf\x83\xe1\x35\x7e\xef\xb8\xbd\xf1\x54\x28\x50\xd6\x6d\x80\x07" 295 "\xd6\x20\xe4\x05\x0b\x57\x15\xdc\x83\xf4\xa9\x21\xd3\x6c\xe9\xce" 296 "\x47\xd0\xd1\x3c\x5d\x85\xf2\xb0\xff\x83\x18\xd2\x87\x7e\xec\x2f" 297 "\x63\xb9\x31\xbd\x47\x41\x7a\x81\xa5\x38\x32\x7a\xf9\x27\xda\x3e" 298 }, 299 { 300 "a", 301 "\x1f\x40\xfc\x92\xda\x24\x16\x94\x75\x09\x79\xee\x6c\xf5\x82\xf2" 302 "\xd5\xd7\xd2\x8e\x18\x33\x5d\xe0\x5a\xbc\x54\xd0\x56\x0e\x0f\x53" 303 "\x02\x86\x0c\x65\x2b\xf0\x8d\x56\x02\x52\xaa\x5e\x74\x21\x05\x46" 304 "\xf3\x69\xfb\xbb\xce\x8c\x12\xcf\xc7\x95\x7b\x26\x52\xfe\x9a\x75" 305 }, 306 { 307 "message digest", 308 "\x10\x7d\xbf\x38\x9d\x9e\x9f\x71\xa3\xa9\x5f\x6c\x05\x5b\x92\x51" 309 "\xbc\x52\x68\xc2\xbe\x16\xd6\xc1\x34\x92\xea\x45\xb0\x19\x9f\x33" 310 "\x09\xe1\x64\x55\xab\x1e\x96\x11\x8e\x8a\x90\x5d\x55\x97\xb7\x20" 311 "\x38\xdd\xb3\x72\xa8\x98\x26\x04\x6d\xe6\x66\x87\xbb\x42\x0e\x7c" 312 }, 313 { 314 "abcdefghijklmnopqrstuvwxyz", 315 "\x4d\xbf\xf8\x6c\xc2\xca\x1b\xae\x1e\x16\x46\x8a\x05\xcb\x98\x81" 316 "\xc9\x7f\x17\x53\xbc\xe3\x61\x90\x34\x89\x8f\xaa\x1a\xab\xe4\x29" 317 "\x95\x5a\x1b\xf8\xec\x48\x3d\x74\x21\xfe\x3c\x16\x46\x61\x3a\x59" 318 "\xed\x54\x41\xfb\x0f\x32\x13\x89\xf7\x7f\x48\xa8\x79\xc7\xb1\xf1" 319 }, 320 { 321 "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 322 "\x20\x4a\x8f\xc6\xdd\xa8\x2f\x0a\x0c\xed\x7b\xeb\x8e\x08\xa4\x16" 323 "\x57\xc1\x6e\xf4\x68\xb2\x28\xa8\x27\x9b\xe3\x31\xa7\x03\xc3\x35" 324 "\x96\xfd\x15\xc1\x3b\x1b\x07\xf9\xaa\x1d\x3b\xea\x57\x78\x9c\xa0" 325 "\x31\xad\x85\xc7\xa7\x1d\xd7\x03\x54\xec\x63\x12\x38\xca\x34\x45" 326 }, 327 { 328 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 329 "\x1e\x07\xbe\x23\xc2\x6a\x86\xea\x37\xea\x81\x0c\x8e\xc7\x80\x93" 330 "\x52\x51\x5a\x97\x0e\x92\x53\xc2\x6f\x53\x6c\xfc\x7a\x99\x96\xc4" 331 "\x5c\x83\x70\x58\x3e\x0a\x78\xfa\x4a\x90\x04\x1d\x71\xa4\xce\xab" 332 "\x74\x23\xf1\x9c\x71\xb9\xd5\xa3\xe0\x12\x49\xf0\xbe\xbd\x58\x94" 333 }, 334 { 335 "123456789012345678901234567890123456789012345678901234567890" 336 "12345678901234567890", 337 "\x72\xec\x1e\xf1\x12\x4a\x45\xb0\x47\xe8\xb7\xc7\x5a\x93\x21\x95" 338 "\x13\x5b\xb6\x1d\xe2\x4e\xc0\xd1\x91\x40\x42\x24\x6e\x0a\xec\x3a" 339 "\x23\x54\xe0\x93\xd7\x6f\x30\x48\xb4\x56\x76\x43\x46\x90\x0c\xb1" 340 "\x30\xd2\xa4\xfd\x5d\xd1\x6a\xbb\x5e\x30\xbc\xb8\x50\xde\xe8\x43" 341 } 342 }; 343 344 #define ntests (sizeof (tests) / sizeof (tests[0])) 345 346 static const struct { 347 const char *salt; 348 const char *input; 349 const char *expected; 350 } tests2[] = 351 { 352 { 353 "$6$saltstring", "Hello world!", 354 "$6$saltstring$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJu" 355 "esI68u4OTLiBFdcbYEdFCoEOfaS35inz1" 356 }, 357 { 358 "$6$rounds=10000$saltstringsaltstring", "Hello world!", 359 "$6$rounds=10000$saltstringsaltst$OW1/O6BYHV6BcXZu8QVeXbDWra3Oeqh0sb" 360 "HbbMCVNSnCM/UrjmM0Dp8vOuZeHBy/YTBmSK6H9qs/y3RnOaw5v." 361 }, 362 { 363 "$6$rounds=5000$toolongsaltstring", "This is just a test", 364 "$6$rounds=5000$toolongsaltstrin$lQ8jolhgVRVhY4b5pZKaysCLi0QBxGoNeKQ" 365 "zQ3glMhwllF7oGDZxUhx1yxdYcz/e1JSbq3y6JMxxl8audkUEm0" 366 }, 367 { 368 "$6$rounds=1400$anotherlongsaltstring", 369 "a very much longer text to encrypt. This one even stretches over more" 370 "than one line.", 371 "$6$rounds=1400$anotherlongsalts$POfYwTEok97VWcjxIiSOjiykti.o/pQs.wP" 372 "vMxQ6Fm7I6IoYN3CmLs66x9t0oSwbtEW7o7UmJEiDwGqd8p4ur1" 373 }, 374 { 375 "$6$rounds=77777$short", 376 "we have a short salt string but not a short password", 377 "$6$rounds=77777$short$WuQyW2YR.hBNpjjRhpYD/ifIw05xdfeEyQoMxIXbkvr0g" 378 "ge1a1x3yRULJ5CCaUeOxFmtlcGZelFl5CxtgfiAc0" 379 }, 380 { 381 "$6$rounds=123456$asaltof16chars..", "a short string", 382 "$6$rounds=123456$asaltof16chars..$BtCwjqMJGx5hrJhZywWvt0RLE8uZ4oPwc" 383 "elCjmw2kSYu.Ec6ycULevoBK25fs2xXgMNrCzIMVcgEJAstJeonj1" 384 }, 385 { 386 "$6$rounds=10$roundstoolow", "the minimum number is still observed", 387 "$6$rounds=1000$roundstoolow$kUMsbe306n21p9R.FRkW3IGn.S9NPN0x50YhH1x" 388 "hLsPuWGsUSklZt58jaTfF4ZEQpyUNGc0dqbpBYYBaHHrsX." 389 }, 390 }; 391 392 #define ntests2 (sizeof (tests2) / sizeof (tests2[0])) 393 394 int 395 main(void) 396 { 397 SHA512_CTX ctx; 398 uint8_t sum[64]; 399 int result = 0; 400 int i, cnt; 401 402 for (cnt = 0; cnt < (int)ntests; ++cnt) { 403 SHA512_Init(&ctx); 404 SHA512_Update(&ctx, tests[cnt].input, strlen(tests[cnt].input)); 405 SHA512_Final(sum, &ctx); 406 if (memcmp(tests[cnt].result, sum, 64) != 0) { 407 printf("test %d run %d failed\n", cnt, 1); 408 result = 1; 409 } 410 411 SHA512_Init(&ctx); 412 for (i = 0; tests[cnt].input[i] != '\0'; ++i) 413 SHA512_Update(&ctx, &tests[cnt].input[i], 1); 414 SHA512_Final(sum, &ctx); 415 if (memcmp(tests[cnt].result, sum, 64) != 0) { 416 printf("test %d run %d failed\n", cnt, 2); 417 result = 1; 418 } 419 } 420 421 /* Test vector from FIPS 180-2: appendix C.3. */ 422 char buf[1000]; 423 424 memset(buf, 'a', sizeof(buf)); 425 SHA512_Init(&ctx); 426 for (i = 0; i < 1000; ++i) 427 SHA512_Update(&ctx, buf, sizeof(buf)); 428 SHA512_Final(sum, &ctx); 429 static const char expected[64] = 430 "\xe7\x18\x48\x3d\x0c\xe7\x69\x64\x4e\x2e\x42\xc7\xbc\x15\xb4\x63" 431 "\x8e\x1f\x98\xb1\x3b\x20\x44\x28\x56\x32\xa8\x03\xaf\xa9\x73\xeb" 432 "\xde\x0f\xf2\x44\x87\x7e\xa6\x0a\x4c\xb0\x43\x2c\xe5\x77\xc3\x1b" 433 "\xeb\x00\x9c\x5c\x2c\x49\xaa\x2e\x4e\xad\xb2\x17\xad\x8c\xc0\x9b"; 434 435 if (memcmp(expected, sum, 64) != 0) { 436 printf("test %d failed\n", cnt); 437 result = 1; 438 } 439 440 for (cnt = 0; cnt < ntests2; ++cnt) { 441 char *cp = crypt_sha512(tests2[cnt].input, tests2[cnt].salt); 442 443 if (strcmp(cp, tests2[cnt].expected) != 0) { 444 printf("test %d: expected \"%s\", got \"%s\"\n", 445 cnt, tests2[cnt].expected, cp); 446 result = 1; 447 } 448 } 449 450 if (result == 0) 451 puts("all tests OK"); 452 453 return result; 454 } 455 456 #endif /* TEST */ 457