]>
Commit | Line | Data |
---|---|---|
c3266dc0 | 1 | /* One way encryption based on SHA512 sum. |
568035b7 | 2 | Copyright (C) 2007-2013 Free Software Foundation, Inc. |
c3266dc0 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2007. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
c3266dc0 UD |
19 | |
20 | #include <assert.h> | |
21 | #include <errno.h> | |
22 | #include <stdbool.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
e054f494 | 25 | #include <stdint.h> |
c3266dc0 UD |
26 | #include <sys/param.h> |
27 | ||
28 | #include "sha512.h" | |
29 | ||
30 | ||
ff886b82 UD |
31 | #ifdef USE_NSS |
32 | typedef int PRBool; | |
33 | # include <hasht.h> | |
34 | # include <nsslowhash.h> | |
35 | ||
36 | # define sha512_init_ctx(ctxp, nss_ctxp) \ | |
37 | do \ | |
38 | { \ | |
39 | if (((nss_ctxp = NSSLOWHASH_NewContext (nss_ictx, HASH_AlgSHA512)) \ | |
40 | == NULL)) \ | |
41 | { \ | |
42 | if (nss_ctx != NULL) \ | |
43 | NSSLOWHASH_Destroy (nss_ctx); \ | |
44 | if (nss_alt_ctx != NULL) \ | |
45 | NSSLOWHASH_Destroy (nss_alt_ctx); \ | |
46 | return NULL; \ | |
47 | } \ | |
48 | NSSLOWHASH_Begin (nss_ctxp); \ | |
49 | } \ | |
50 | while (0) | |
51 | ||
52 | # define sha512_process_bytes(buf, len, ctxp, nss_ctxp) \ | |
53 | NSSLOWHASH_Update (nss_ctxp, (const unsigned char *) buf, len) | |
54 | ||
55 | # define sha512_finish_ctx(ctxp, nss_ctxp, result) \ | |
56 | do \ | |
57 | { \ | |
58 | unsigned int ret; \ | |
59 | NSSLOWHASH_End (nss_ctxp, result, &ret, sizeof (result)); \ | |
60 | assert (ret == sizeof (result)); \ | |
61 | NSSLOWHASH_Destroy (nss_ctxp); \ | |
62 | nss_ctxp = NULL; \ | |
63 | } \ | |
64 | while (0) | |
65 | #else | |
66 | # define sha512_init_ctx(ctxp, nss_ctxp) \ | |
67 | __sha512_init_ctx (ctxp) | |
68 | ||
69 | # define sha512_process_bytes(buf, len, ctxp, nss_ctxp) \ | |
70 | __sha512_process_bytes(buf, len, ctxp) | |
71 | ||
72 | # define sha512_finish_ctx(ctxp, nss_ctxp, result) \ | |
73 | __sha512_finish_ctx (ctxp, result) | |
74 | #endif | |
75 | ||
76 | ||
c3266dc0 UD |
77 | /* Define our magic string to mark salt for SHA512 "encryption" |
78 | replacement. */ | |
79 | static const char sha512_salt_prefix[] = "$6$"; | |
80 | ||
81 | /* Prefix for optional rounds specification. */ | |
82 | static const char sha512_rounds_prefix[] = "rounds="; | |
83 | ||
84 | /* Maximum salt string length. */ | |
85 | #define SALT_LEN_MAX 16 | |
86 | /* Default number of rounds if not explicitly specified. */ | |
87 | #define ROUNDS_DEFAULT 5000 | |
88 | /* Minimum number of rounds. */ | |
89 | #define ROUNDS_MIN 1000 | |
90 | /* Maximum number of rounds. */ | |
91 | #define ROUNDS_MAX 999999999 | |
92 | ||
93 | /* Table with characters for base64 transformation. */ | |
94 | static const char b64t[64] = | |
95 | "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; | |
96 | ||
97 | ||
98 | /* Prototypes for local functions. */ | |
99 | extern char *__sha512_crypt_r (const char *key, const char *salt, | |
100 | char *buffer, int buflen); | |
101 | extern char *__sha512_crypt (const char *key, const char *salt); | |
102 | ||
103 | ||
104 | char * | |
105 | __sha512_crypt_r (key, salt, buffer, buflen) | |
106 | const char *key; | |
107 | const char *salt; | |
108 | char *buffer; | |
109 | int buflen; | |
110 | { | |
111 | unsigned char alt_result[64] | |
112 | __attribute__ ((__aligned__ (__alignof__ (uint64_t)))); | |
113 | unsigned char temp_result[64] | |
114 | __attribute__ ((__aligned__ (__alignof__ (uint64_t)))); | |
c3266dc0 UD |
115 | size_t salt_len; |
116 | size_t key_len; | |
117 | size_t cnt; | |
118 | char *cp; | |
119 | char *copied_key = NULL; | |
120 | char *copied_salt = NULL; | |
121 | char *p_bytes; | |
122 | char *s_bytes; | |
123 | /* Default number of rounds. */ | |
124 | size_t rounds = ROUNDS_DEFAULT; | |
125 | bool rounds_custom = false; | |
b8dc394d JL |
126 | size_t alloca_used = 0; |
127 | char *free_key = NULL; | |
128 | char *free_pbytes = NULL; | |
c3266dc0 UD |
129 | |
130 | /* Find beginning of salt string. The prefix should normally always | |
131 | be present. Just in case it is not. */ | |
132 | if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0) | |
133 | /* Skip salt prefix. */ | |
134 | salt += sizeof (sha512_salt_prefix) - 1; | |
135 | ||
136 | if (strncmp (salt, sha512_rounds_prefix, sizeof (sha512_rounds_prefix) - 1) | |
137 | == 0) | |
138 | { | |
139 | const char *num = salt + sizeof (sha512_rounds_prefix) - 1; | |
140 | char *endp; | |
141 | unsigned long int srounds = strtoul (num, &endp, 10); | |
142 | if (*endp == '$') | |
143 | { | |
144 | salt = endp + 1; | |
145 | rounds = MAX (ROUNDS_MIN, MIN (srounds, ROUNDS_MAX)); | |
146 | rounds_custom = true; | |
147 | } | |
148 | } | |
149 | ||
150 | salt_len = MIN (strcspn (salt, "$"), SALT_LEN_MAX); | |
151 | key_len = strlen (key); | |
152 | ||
153 | if ((key - (char *) 0) % __alignof__ (uint64_t) != 0) | |
154 | { | |
b8dc394d JL |
155 | char *tmp; |
156 | ||
157 | if (__libc_use_alloca (alloca_used + key_len + __alignof__ (uint64_t))) | |
158 | tmp = alloca_account (key_len + __alignof__ (uint64_t), alloca_used); | |
159 | else | |
160 | { | |
161 | free_key = tmp = (char *) malloc (key_len + __alignof__ (uint64_t)); | |
162 | if (tmp == NULL) | |
163 | return NULL; | |
164 | } | |
165 | ||
c3266dc0 UD |
166 | key = copied_key = |
167 | memcpy (tmp + __alignof__ (uint64_t) | |
168 | - (tmp - (char *) 0) % __alignof__ (uint64_t), | |
169 | key, key_len); | |
170 | assert ((key - (char *) 0) % __alignof__ (uint64_t) == 0); | |
171 | } | |
172 | ||
173 | if ((salt - (char *) 0) % __alignof__ (uint64_t) != 0) | |
174 | { | |
175 | char *tmp = (char *) alloca (salt_len + __alignof__ (uint64_t)); | |
176 | salt = copied_salt = | |
177 | memcpy (tmp + __alignof__ (uint64_t) | |
178 | - (tmp - (char *) 0) % __alignof__ (uint64_t), | |
179 | salt, salt_len); | |
180 | assert ((salt - (char *) 0) % __alignof__ (uint64_t) == 0); | |
181 | } | |
182 | ||
ff886b82 UD |
183 | #ifdef USE_NSS |
184 | /* Initialize libfreebl3. */ | |
185 | NSSLOWInitContext *nss_ictx = NSSLOW_Init (); | |
186 | if (nss_ictx == NULL) | |
b8dc394d JL |
187 | { |
188 | free (free_key); | |
189 | return NULL; | |
190 | } | |
ff886b82 UD |
191 | NSSLOWHASHContext *nss_ctx = NULL; |
192 | NSSLOWHASHContext *nss_alt_ctx = NULL; | |
193 | #else | |
194 | struct sha512_ctx ctx; | |
195 | struct sha512_ctx alt_ctx; | |
196 | #endif | |
197 | ||
c3266dc0 | 198 | /* Prepare for the real work. */ |
ff886b82 | 199 | sha512_init_ctx (&ctx, nss_ctx); |
c3266dc0 UD |
200 | |
201 | /* Add the key string. */ | |
ff886b82 | 202 | sha512_process_bytes (key, key_len, &ctx, nss_ctx); |
c3266dc0 | 203 | |
7f745396 UD |
204 | /* The last part is the salt string. This must be at most 16 |
205 | characters and it ends at the first `$' character. */ | |
ff886b82 | 206 | sha512_process_bytes (salt, salt_len, &ctx, nss_ctx); |
c3266dc0 UD |
207 | |
208 | ||
209 | /* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The | |
210 | final result will be added to the first context. */ | |
ff886b82 | 211 | sha512_init_ctx (&alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
212 | |
213 | /* Add key. */ | |
ff886b82 | 214 | sha512_process_bytes (key, key_len, &alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
215 | |
216 | /* Add salt. */ | |
ff886b82 | 217 | sha512_process_bytes (salt, salt_len, &alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
218 | |
219 | /* Add key again. */ | |
ff886b82 | 220 | sha512_process_bytes (key, key_len, &alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
221 | |
222 | /* Now get result of this (64 bytes) and add it to the other | |
223 | context. */ | |
ff886b82 | 224 | sha512_finish_ctx (&alt_ctx, nss_alt_ctx, alt_result); |
c3266dc0 UD |
225 | |
226 | /* Add for any character in the key one byte of the alternate sum. */ | |
227 | for (cnt = key_len; cnt > 64; cnt -= 64) | |
ff886b82 UD |
228 | sha512_process_bytes (alt_result, 64, &ctx, nss_ctx); |
229 | sha512_process_bytes (alt_result, cnt, &ctx, nss_ctx); | |
c3266dc0 UD |
230 | |
231 | /* Take the binary representation of the length of the key and for every | |
232 | 1 add the alternate sum, for every 0 the key. */ | |
233 | for (cnt = key_len; cnt > 0; cnt >>= 1) | |
234 | if ((cnt & 1) != 0) | |
ff886b82 | 235 | sha512_process_bytes (alt_result, 64, &ctx, nss_ctx); |
c3266dc0 | 236 | else |
ff886b82 | 237 | sha512_process_bytes (key, key_len, &ctx, nss_ctx); |
c3266dc0 UD |
238 | |
239 | /* Create intermediate result. */ | |
ff886b82 | 240 | sha512_finish_ctx (&ctx, nss_ctx, alt_result); |
c3266dc0 UD |
241 | |
242 | /* Start computation of P byte sequence. */ | |
ff886b82 | 243 | sha512_init_ctx (&alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
244 | |
245 | /* For every character in the password add the entire password. */ | |
246 | for (cnt = 0; cnt < key_len; ++cnt) | |
ff886b82 | 247 | sha512_process_bytes (key, key_len, &alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
248 | |
249 | /* Finish the digest. */ | |
ff886b82 | 250 | sha512_finish_ctx (&alt_ctx, nss_alt_ctx, temp_result); |
c3266dc0 UD |
251 | |
252 | /* Create byte sequence P. */ | |
b8dc394d JL |
253 | if (__libc_use_alloca (alloca_used + key_len)) |
254 | cp = p_bytes = (char *) alloca (key_len); | |
255 | else | |
256 | { | |
257 | free_pbytes = cp = p_bytes = (char *)malloc (key_len); | |
258 | if (free_pbytes == NULL) | |
259 | { | |
260 | free (free_key); | |
261 | return NULL; | |
262 | } | |
263 | } | |
264 | ||
c3266dc0 UD |
265 | for (cnt = key_len; cnt >= 64; cnt -= 64) |
266 | cp = mempcpy (cp, temp_result, 64); | |
267 | memcpy (cp, temp_result, cnt); | |
268 | ||
269 | /* Start computation of S byte sequence. */ | |
ff886b82 | 270 | sha512_init_ctx (&alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
271 | |
272 | /* For every character in the password add the entire password. */ | |
273 | for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt) | |
ff886b82 | 274 | sha512_process_bytes (salt, salt_len, &alt_ctx, nss_alt_ctx); |
c3266dc0 UD |
275 | |
276 | /* Finish the digest. */ | |
ff886b82 | 277 | sha512_finish_ctx (&alt_ctx, nss_alt_ctx, temp_result); |
c3266dc0 UD |
278 | |
279 | /* Create byte sequence S. */ | |
280 | cp = s_bytes = alloca (salt_len); | |
281 | for (cnt = salt_len; cnt >= 64; cnt -= 64) | |
282 | cp = mempcpy (cp, temp_result, 64); | |
283 | memcpy (cp, temp_result, cnt); | |
284 | ||
285 | /* Repeatedly run the collected hash value through SHA512 to burn | |
286 | CPU cycles. */ | |
287 | for (cnt = 0; cnt < rounds; ++cnt) | |
288 | { | |
289 | /* New context. */ | |
ff886b82 | 290 | sha512_init_ctx (&ctx, nss_ctx); |
c3266dc0 UD |
291 | |
292 | /* Add key or last result. */ | |
293 | if ((cnt & 1) != 0) | |
ff886b82 | 294 | sha512_process_bytes (p_bytes, key_len, &ctx, nss_ctx); |
c3266dc0 | 295 | else |
ff886b82 | 296 | sha512_process_bytes (alt_result, 64, &ctx, nss_ctx); |
c3266dc0 UD |
297 | |
298 | /* Add salt for numbers not divisible by 3. */ | |
299 | if (cnt % 3 != 0) | |
ff886b82 | 300 | sha512_process_bytes (s_bytes, salt_len, &ctx, nss_ctx); |
c3266dc0 UD |
301 | |
302 | /* Add key for numbers not divisible by 7. */ | |
303 | if (cnt % 7 != 0) | |
ff886b82 | 304 | sha512_process_bytes (p_bytes, key_len, &ctx, nss_ctx); |
c3266dc0 UD |
305 | |
306 | /* Add key or last result. */ | |
307 | if ((cnt & 1) != 0) | |
ff886b82 | 308 | sha512_process_bytes (alt_result, 64, &ctx, nss_ctx); |
c3266dc0 | 309 | else |
ff886b82 | 310 | sha512_process_bytes (p_bytes, key_len, &ctx, nss_ctx); |
c3266dc0 UD |
311 | |
312 | /* Create intermediate result. */ | |
ff886b82 | 313 | sha512_finish_ctx (&ctx, nss_ctx, alt_result); |
c3266dc0 UD |
314 | } |
315 | ||
ff886b82 UD |
316 | #ifdef USE_NSS |
317 | /* Free libfreebl3 resources. */ | |
318 | NSSLOW_Shutdown (nss_ictx); | |
319 | #endif | |
320 | ||
c3266dc0 UD |
321 | /* Now we can construct the result string. It consists of three |
322 | parts. */ | |
323 | cp = __stpncpy (buffer, sha512_salt_prefix, MAX (0, buflen)); | |
324 | buflen -= sizeof (sha512_salt_prefix) - 1; | |
325 | ||
326 | if (rounds_custom) | |
327 | { | |
328 | int n = snprintf (cp, MAX (0, buflen), "%s%zu$", | |
329 | sha512_rounds_prefix, rounds); | |
330 | cp += n; | |
331 | buflen -= n; | |
332 | } | |
333 | ||
334 | cp = __stpncpy (cp, salt, MIN ((size_t) MAX (0, buflen), salt_len)); | |
335 | buflen -= MIN ((size_t) MAX (0, buflen), salt_len); | |
336 | ||
337 | if (buflen > 0) | |
338 | { | |
339 | *cp++ = '$'; | |
340 | --buflen; | |
341 | } | |
342 | ||
ff886b82 UD |
343 | void b64_from_24bit (unsigned int b2, unsigned int b1, unsigned int b0, |
344 | int n) | |
345 | { | |
346 | unsigned int w = (b2 << 16) | (b1 << 8) | b0; | |
347 | while (n-- > 0 && buflen > 0) | |
348 | { | |
349 | *cp++ = b64t[w & 0x3f]; | |
350 | --buflen; | |
351 | w >>= 6; | |
352 | } | |
353 | } | |
c3266dc0 UD |
354 | |
355 | b64_from_24bit (alt_result[0], alt_result[21], alt_result[42], 4); | |
356 | b64_from_24bit (alt_result[22], alt_result[43], alt_result[1], 4); | |
357 | b64_from_24bit (alt_result[44], alt_result[2], alt_result[23], 4); | |
358 | b64_from_24bit (alt_result[3], alt_result[24], alt_result[45], 4); | |
359 | b64_from_24bit (alt_result[25], alt_result[46], alt_result[4], 4); | |
360 | b64_from_24bit (alt_result[47], alt_result[5], alt_result[26], 4); | |
361 | b64_from_24bit (alt_result[6], alt_result[27], alt_result[48], 4); | |
362 | b64_from_24bit (alt_result[28], alt_result[49], alt_result[7], 4); | |
363 | b64_from_24bit (alt_result[50], alt_result[8], alt_result[29], 4); | |
364 | b64_from_24bit (alt_result[9], alt_result[30], alt_result[51], 4); | |
365 | b64_from_24bit (alt_result[31], alt_result[52], alt_result[10], 4); | |
366 | b64_from_24bit (alt_result[53], alt_result[11], alt_result[32], 4); | |
367 | b64_from_24bit (alt_result[12], alt_result[33], alt_result[54], 4); | |
368 | b64_from_24bit (alt_result[34], alt_result[55], alt_result[13], 4); | |
369 | b64_from_24bit (alt_result[56], alt_result[14], alt_result[35], 4); | |
370 | b64_from_24bit (alt_result[15], alt_result[36], alt_result[57], 4); | |
371 | b64_from_24bit (alt_result[37], alt_result[58], alt_result[16], 4); | |
372 | b64_from_24bit (alt_result[59], alt_result[17], alt_result[38], 4); | |
373 | b64_from_24bit (alt_result[18], alt_result[39], alt_result[60], 4); | |
374 | b64_from_24bit (alt_result[40], alt_result[61], alt_result[19], 4); | |
375 | b64_from_24bit (alt_result[62], alt_result[20], alt_result[41], 4); | |
376 | b64_from_24bit (0, 0, alt_result[63], 2); | |
377 | ||
378 | if (buflen <= 0) | |
379 | { | |
380 | __set_errno (ERANGE); | |
381 | buffer = NULL; | |
382 | } | |
383 | else | |
384 | *cp = '\0'; /* Terminate the string. */ | |
385 | ||
386 | /* Clear the buffer for the intermediate result so that people | |
387 | attaching to processes or reading core dumps cannot get any | |
388 | information. We do it in this way to clear correct_words[] | |
389 | inside the SHA512 implementation as well. */ | |
ff886b82 | 390 | #ifndef USE_NSS |
c3266dc0 UD |
391 | __sha512_init_ctx (&ctx); |
392 | __sha512_finish_ctx (&ctx, alt_result); | |
ff886b82 UD |
393 | memset (&ctx, '\0', sizeof (ctx)); |
394 | memset (&alt_ctx, '\0', sizeof (alt_ctx)); | |
395 | #endif | |
c3266dc0 UD |
396 | memset (temp_result, '\0', sizeof (temp_result)); |
397 | memset (p_bytes, '\0', key_len); | |
398 | memset (s_bytes, '\0', salt_len); | |
c3266dc0 UD |
399 | if (copied_key != NULL) |
400 | memset (copied_key, '\0', key_len); | |
401 | if (copied_salt != NULL) | |
402 | memset (copied_salt, '\0', salt_len); | |
403 | ||
b8dc394d JL |
404 | free (free_key); |
405 | free (free_pbytes); | |
c3266dc0 UD |
406 | return buffer; |
407 | } | |
408 | ||
409 | #ifndef _LIBC | |
410 | # define libc_freeres_ptr(decl) decl | |
411 | #endif | |
412 | libc_freeres_ptr (static char *buffer); | |
413 | ||
414 | /* This entry point is equivalent to the `crypt' function in Unix | |
415 | libcs. */ | |
416 | char * | |
417 | __sha512_crypt (const char *key, const char *salt) | |
418 | { | |
419 | /* We don't want to have an arbitrary limit in the size of the | |
420 | password. We can compute an upper bound for the size of the | |
421 | result in advance and so we can prepare the buffer we pass to | |
422 | `sha512_crypt_r'. */ | |
423 | static int buflen; | |
424 | int needed = (sizeof (sha512_salt_prefix) - 1 | |
425 | + sizeof (sha512_rounds_prefix) + 9 + 1 | |
426 | + strlen (salt) + 1 + 86 + 1); | |
427 | ||
428 | if (buflen < needed) | |
429 | { | |
430 | char *new_buffer = (char *) realloc (buffer, needed); | |
431 | if (new_buffer == NULL) | |
432 | return NULL; | |
433 | ||
434 | buffer = new_buffer; | |
435 | buflen = needed; | |
436 | } | |
437 | ||
438 | return __sha512_crypt_r (key, salt, buffer, buflen); | |
439 | } | |
440 | ||
441 | #ifndef _LIBC | |
442 | static void | |
443 | __attribute__ ((__destructor__)) | |
444 | free_mem (void) | |
445 | { | |
446 | free (buffer); | |
447 | } | |
448 | #endif |