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