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