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
crypt_sha512(const char * key,const char * salt,char * buffer)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
main(void)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