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