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05697ec1 NB |
1 | /* sha1.c - Functions to compute SHA1 message digest of files or |
2 | memory blocks according to the NIST specification FIPS-180-1. | |
3 | ||
4 | Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 2, or (at your option) any | |
9 | later version. | |
10 | ||
11 | This program 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 | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software Foundation, | |
18 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
19 | ||
20 | /* Written by Scott G. Miller | |
21 | Credits: | |
22 | Robert Klep <robert@ilse.nl> -- Expansion function fix | |
23 | */ | |
24 | ||
25 | #ifdef HAVE_CONFIG_H | |
26 | # include <config.h> | |
27 | #endif | |
28 | ||
29 | #include "sha1.h" | |
30 | ||
31 | #include <stddef.h> | |
32 | #include <string.h> | |
33 | ||
34 | #if USE_UNLOCKED_IO | |
35 | # include "unlocked-io.h" | |
36 | #endif | |
37 | ||
38 | /* SWAP does an endian swap on architectures that are little-endian, | |
39 | as SHA1 needs some data in a big-endian form. */ | |
40 | ||
41 | #ifdef WORDS_BIGENDIAN | |
42 | # define SWAP(n) (n) | |
43 | #else | |
44 | # define SWAP(n) \ | |
45 | (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) | |
46 | #endif | |
47 | ||
48 | #define BLOCKSIZE 4096 | |
49 | #if BLOCKSIZE % 64 != 0 | |
50 | # error "invalid BLOCKSIZE" | |
51 | #endif | |
52 | ||
53 | /* This array contains the bytes used to pad the buffer to the next | |
54 | 64-byte boundary. (RFC 1321, 3.1: Step 1) */ | |
55 | static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; | |
56 | ||
57 | ||
58 | /* | |
59 | Takes a pointer to a 160 bit block of data (five 32 bit ints) and | |
60 | intializes it to the start constants of the SHA1 algorithm. This | |
61 | must be called before using hash in the call to sha1_hash. | |
62 | */ | |
63 | void | |
64 | sha1_init_ctx (struct sha1_ctx *ctx) | |
65 | { | |
66 | ctx->A = 0x67452301; | |
67 | ctx->B = 0xefcdab89; | |
68 | ctx->C = 0x98badcfe; | |
69 | ctx->D = 0x10325476; | |
70 | ctx->E = 0xc3d2e1f0; | |
71 | ||
72 | ctx->total[0] = ctx->total[1] = 0; | |
73 | ctx->buflen = 0; | |
74 | } | |
75 | ||
76 | /* Put result from CTX in first 20 bytes following RESBUF. The result | |
77 | must be in little endian byte order. | |
78 | ||
79 | IMPORTANT: On some systems it is required that RESBUF is correctly | |
80 | aligned for a 32 bits value. */ | |
81 | void * | |
82 | sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf) | |
83 | { | |
84 | ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A); | |
85 | ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B); | |
86 | ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C); | |
87 | ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D); | |
88 | ((md5_uint32 *) resbuf)[4] = SWAP (ctx->E); | |
89 | ||
90 | return resbuf; | |
91 | } | |
92 | ||
93 | /* Process the remaining bytes in the internal buffer and the usual | |
94 | prolog according to the standard and write the result to RESBUF. | |
95 | ||
96 | IMPORTANT: On some systems it is required that RESBUF is correctly | |
97 | aligned for a 32 bits value. */ | |
98 | void * | |
99 | sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf) | |
100 | { | |
101 | /* Take yet unprocessed bytes into account. */ | |
102 | md5_uint32 bytes = ctx->buflen; | |
103 | size_t pad; | |
104 | ||
105 | /* Now count remaining bytes. */ | |
106 | ctx->total[0] += bytes; | |
107 | if (ctx->total[0] < bytes) | |
108 | ++ctx->total[1]; | |
109 | ||
110 | pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; | |
111 | memcpy (&ctx->buffer[bytes], fillbuf, pad); | |
112 | ||
113 | /* Put the 64-bit file length in *bits* at the end of the buffer. */ | |
114 | *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP (ctx->total[0] << 3); | |
115 | *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) | | |
116 | (ctx->total[0] >> 29)); | |
117 | ||
118 | /* Process last bytes. */ | |
119 | sha1_process_block (ctx->buffer, bytes + pad + 8, ctx); | |
120 | ||
121 | return sha1_read_ctx (ctx, resbuf); | |
122 | } | |
123 | ||
124 | /* Compute SHA1 message digest for bytes read from STREAM. The | |
125 | resulting message digest number will be written into the 16 bytes | |
126 | beginning at RESBLOCK. */ | |
127 | int | |
128 | sha1_stream (FILE *stream, void *resblock) | |
129 | { | |
130 | struct sha1_ctx ctx; | |
131 | char buffer[BLOCKSIZE + 72]; | |
132 | size_t sum; | |
133 | ||
134 | /* Initialize the computation context. */ | |
135 | sha1_init_ctx (&ctx); | |
136 | ||
137 | /* Iterate over full file contents. */ | |
138 | while (1) | |
139 | { | |
140 | /* We read the file in blocks of BLOCKSIZE bytes. One call of the | |
141 | computation function processes the whole buffer so that with the | |
142 | next round of the loop another block can be read. */ | |
143 | size_t n; | |
144 | sum = 0; | |
145 | ||
146 | /* Read block. Take care for partial reads. */ | |
147 | while (1) | |
148 | { | |
149 | n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); | |
150 | ||
151 | sum += n; | |
152 | ||
153 | if (sum == BLOCKSIZE) | |
154 | break; | |
155 | ||
156 | if (n == 0) | |
157 | { | |
158 | /* Check for the error flag IFF N == 0, so that we don't | |
159 | exit the loop after a partial read due to e.g., EAGAIN | |
160 | or EWOULDBLOCK. */ | |
161 | if (ferror (stream)) | |
162 | return 1; | |
163 | goto process_partial_block; | |
164 | } | |
165 | ||
166 | /* We've read at least one byte, so ignore errors. But always | |
167 | check for EOF, since feof may be true even though N > 0. | |
168 | Otherwise, we could end up calling fread after EOF. */ | |
169 | if (feof (stream)) | |
170 | goto process_partial_block; | |
171 | } | |
172 | ||
173 | /* Process buffer with BLOCKSIZE bytes. Note that | |
174 | BLOCKSIZE % 64 == 0 | |
175 | */ | |
176 | sha1_process_block (buffer, BLOCKSIZE, &ctx); | |
177 | } | |
178 | ||
179 | process_partial_block:; | |
180 | ||
181 | /* Process any remaining bytes. */ | |
182 | if (sum > 0) | |
183 | sha1_process_bytes (buffer, sum, &ctx); | |
184 | ||
185 | /* Construct result in desired memory. */ | |
186 | sha1_finish_ctx (&ctx, resblock); | |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The | |
191 | result is always in little endian byte order, so that a byte-wise | |
192 | output yields to the wanted ASCII representation of the message | |
193 | digest. */ | |
194 | void * | |
195 | sha1_buffer (const char *buffer, size_t len, void *resblock) | |
196 | { | |
197 | struct sha1_ctx ctx; | |
198 | ||
199 | /* Initialize the computation context. */ | |
200 | sha1_init_ctx (&ctx); | |
201 | ||
202 | /* Process whole buffer but last len % 64 bytes. */ | |
203 | sha1_process_bytes (buffer, len, &ctx); | |
204 | ||
205 | /* Put result in desired memory area. */ | |
206 | return sha1_finish_ctx (&ctx, resblock); | |
207 | } | |
208 | ||
209 | void | |
210 | sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) | |
211 | { | |
212 | /* When we already have some bits in our internal buffer concatenate | |
213 | both inputs first. */ | |
214 | if (ctx->buflen != 0) | |
215 | { | |
216 | size_t left_over = ctx->buflen; | |
217 | size_t add = 128 - left_over > len ? len : 128 - left_over; | |
218 | ||
219 | memcpy (&ctx->buffer[left_over], buffer, add); | |
220 | ctx->buflen += add; | |
221 | ||
222 | if (ctx->buflen > 64) | |
223 | { | |
224 | sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx); | |
225 | ||
226 | ctx->buflen &= 63; | |
227 | /* The regions in the following copy operation cannot overlap. */ | |
228 | memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63], | |
229 | ctx->buflen); | |
230 | } | |
231 | ||
232 | buffer = (const char *) buffer + add; | |
233 | len -= add; | |
234 | } | |
235 | ||
236 | /* Process available complete blocks. */ | |
237 | if (len >= 64) | |
238 | { | |
239 | #if !_STRING_ARCH_unaligned | |
240 | # define alignof(type) offsetof (struct { char c; type x; }, x) | |
241 | # define UNALIGNED_P(p) (((size_t) p) % alignof (md5_uint32) != 0) | |
242 | if (UNALIGNED_P (buffer)) | |
243 | while (len > 64) | |
244 | { | |
245 | sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); | |
246 | buffer = (const char *) buffer + 64; | |
247 | len -= 64; | |
248 | } | |
249 | else | |
250 | #endif | |
251 | { | |
252 | sha1_process_block (buffer, len & ~63, ctx); | |
253 | buffer = (const char *) buffer + (len & ~63); | |
254 | len &= 63; | |
255 | } | |
256 | } | |
257 | ||
258 | /* Move remaining bytes in internal buffer. */ | |
259 | if (len > 0) | |
260 | { | |
261 | size_t left_over = ctx->buflen; | |
262 | ||
263 | memcpy (&ctx->buffer[left_over], buffer, len); | |
264 | left_over += len; | |
265 | if (left_over >= 64) | |
266 | { | |
267 | sha1_process_block (ctx->buffer, 64, ctx); | |
268 | left_over -= 64; | |
269 | memcpy (ctx->buffer, &ctx->buffer[64], left_over); | |
270 | } | |
271 | ctx->buflen = left_over; | |
272 | } | |
273 | } | |
274 | ||
275 | /* --- Code below is the primary difference between md5.c and sha1.c --- */ | |
276 | ||
277 | /* SHA1 round constants */ | |
278 | #define K1 0x5a827999L | |
279 | #define K2 0x6ed9eba1L | |
280 | #define K3 0x8f1bbcdcL | |
281 | #define K4 0xca62c1d6L | |
282 | ||
283 | /* Round functions. Note that F2 is the same as F4. */ | |
284 | #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) | |
285 | #define F2(B,C,D) (B ^ C ^ D) | |
286 | #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) | |
287 | #define F4(B,C,D) (B ^ C ^ D) | |
288 | ||
289 | /* Process LEN bytes of BUFFER, accumulating context into CTX. | |
290 | It is assumed that LEN % 64 == 0. | |
291 | Most of this code comes from GnuPG's cipher/sha1.c. */ | |
292 | ||
293 | void | |
294 | sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) | |
295 | { | |
296 | const md5_uint32 *words = buffer; | |
297 | size_t nwords = len / sizeof (md5_uint32); | |
298 | const md5_uint32 *endp = words + nwords; | |
299 | md5_uint32 x[16]; | |
300 | md5_uint32 a = ctx->A; | |
301 | md5_uint32 b = ctx->B; | |
302 | md5_uint32 c = ctx->C; | |
303 | md5_uint32 d = ctx->D; | |
304 | md5_uint32 e = ctx->E; | |
305 | ||
306 | /* First increment the byte count. RFC 1321 specifies the possible | |
307 | length of the file up to 2^64 bits. Here we only compute the | |
308 | number of bytes. Do a double word increment. */ | |
309 | ctx->total[0] += len; | |
310 | if (ctx->total[0] < len) | |
311 | ++ctx->total[1]; | |
312 | ||
313 | #define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n)))) | |
314 | ||
315 | #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \ | |
316 | ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \ | |
317 | , (x[I&0x0f] = rol(tm, 1)) ) | |
318 | ||
319 | #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \ | |
320 | + F( B, C, D ) \ | |
321 | + K \ | |
322 | + M; \ | |
323 | B = rol( B, 30 ); \ | |
324 | } while(0) | |
325 | ||
326 | while (words < endp) | |
327 | { | |
328 | md5_uint32 tm; | |
329 | int t; | |
330 | for (t = 0; t < 16; t++) | |
331 | { | |
332 | x[t] = SWAP (*words); | |
333 | words++; | |
334 | } | |
335 | ||
336 | R( a, b, c, d, e, F1, K1, x[ 0] ); | |
337 | R( e, a, b, c, d, F1, K1, x[ 1] ); | |
338 | R( d, e, a, b, c, F1, K1, x[ 2] ); | |
339 | R( c, d, e, a, b, F1, K1, x[ 3] ); | |
340 | R( b, c, d, e, a, F1, K1, x[ 4] ); | |
341 | R( a, b, c, d, e, F1, K1, x[ 5] ); | |
342 | R( e, a, b, c, d, F1, K1, x[ 6] ); | |
343 | R( d, e, a, b, c, F1, K1, x[ 7] ); | |
344 | R( c, d, e, a, b, F1, K1, x[ 8] ); | |
345 | R( b, c, d, e, a, F1, K1, x[ 9] ); | |
346 | R( a, b, c, d, e, F1, K1, x[10] ); | |
347 | R( e, a, b, c, d, F1, K1, x[11] ); | |
348 | R( d, e, a, b, c, F1, K1, x[12] ); | |
349 | R( c, d, e, a, b, F1, K1, x[13] ); | |
350 | R( b, c, d, e, a, F1, K1, x[14] ); | |
351 | R( a, b, c, d, e, F1, K1, x[15] ); | |
352 | R( e, a, b, c, d, F1, K1, M(16) ); | |
353 | R( d, e, a, b, c, F1, K1, M(17) ); | |
354 | R( c, d, e, a, b, F1, K1, M(18) ); | |
355 | R( b, c, d, e, a, F1, K1, M(19) ); | |
356 | R( a, b, c, d, e, F2, K2, M(20) ); | |
357 | R( e, a, b, c, d, F2, K2, M(21) ); | |
358 | R( d, e, a, b, c, F2, K2, M(22) ); | |
359 | R( c, d, e, a, b, F2, K2, M(23) ); | |
360 | R( b, c, d, e, a, F2, K2, M(24) ); | |
361 | R( a, b, c, d, e, F2, K2, M(25) ); | |
362 | R( e, a, b, c, d, F2, K2, M(26) ); | |
363 | R( d, e, a, b, c, F2, K2, M(27) ); | |
364 | R( c, d, e, a, b, F2, K2, M(28) ); | |
365 | R( b, c, d, e, a, F2, K2, M(29) ); | |
366 | R( a, b, c, d, e, F2, K2, M(30) ); | |
367 | R( e, a, b, c, d, F2, K2, M(31) ); | |
368 | R( d, e, a, b, c, F2, K2, M(32) ); | |
369 | R( c, d, e, a, b, F2, K2, M(33) ); | |
370 | R( b, c, d, e, a, F2, K2, M(34) ); | |
371 | R( a, b, c, d, e, F2, K2, M(35) ); | |
372 | R( e, a, b, c, d, F2, K2, M(36) ); | |
373 | R( d, e, a, b, c, F2, K2, M(37) ); | |
374 | R( c, d, e, a, b, F2, K2, M(38) ); | |
375 | R( b, c, d, e, a, F2, K2, M(39) ); | |
376 | R( a, b, c, d, e, F3, K3, M(40) ); | |
377 | R( e, a, b, c, d, F3, K3, M(41) ); | |
378 | R( d, e, a, b, c, F3, K3, M(42) ); | |
379 | R( c, d, e, a, b, F3, K3, M(43) ); | |
380 | R( b, c, d, e, a, F3, K3, M(44) ); | |
381 | R( a, b, c, d, e, F3, K3, M(45) ); | |
382 | R( e, a, b, c, d, F3, K3, M(46) ); | |
383 | R( d, e, a, b, c, F3, K3, M(47) ); | |
384 | R( c, d, e, a, b, F3, K3, M(48) ); | |
385 | R( b, c, d, e, a, F3, K3, M(49) ); | |
386 | R( a, b, c, d, e, F3, K3, M(50) ); | |
387 | R( e, a, b, c, d, F3, K3, M(51) ); | |
388 | R( d, e, a, b, c, F3, K3, M(52) ); | |
389 | R( c, d, e, a, b, F3, K3, M(53) ); | |
390 | R( b, c, d, e, a, F3, K3, M(54) ); | |
391 | R( a, b, c, d, e, F3, K3, M(55) ); | |
392 | R( e, a, b, c, d, F3, K3, M(56) ); | |
393 | R( d, e, a, b, c, F3, K3, M(57) ); | |
394 | R( c, d, e, a, b, F3, K3, M(58) ); | |
395 | R( b, c, d, e, a, F3, K3, M(59) ); | |
396 | R( a, b, c, d, e, F4, K4, M(60) ); | |
397 | R( e, a, b, c, d, F4, K4, M(61) ); | |
398 | R( d, e, a, b, c, F4, K4, M(62) ); | |
399 | R( c, d, e, a, b, F4, K4, M(63) ); | |
400 | R( b, c, d, e, a, F4, K4, M(64) ); | |
401 | R( a, b, c, d, e, F4, K4, M(65) ); | |
402 | R( e, a, b, c, d, F4, K4, M(66) ); | |
403 | R( d, e, a, b, c, F4, K4, M(67) ); | |
404 | R( c, d, e, a, b, F4, K4, M(68) ); | |
405 | R( b, c, d, e, a, F4, K4, M(69) ); | |
406 | R( a, b, c, d, e, F4, K4, M(70) ); | |
407 | R( e, a, b, c, d, F4, K4, M(71) ); | |
408 | R( d, e, a, b, c, F4, K4, M(72) ); | |
409 | R( c, d, e, a, b, F4, K4, M(73) ); | |
410 | R( b, c, d, e, a, F4, K4, M(74) ); | |
411 | R( a, b, c, d, e, F4, K4, M(75) ); | |
412 | R( e, a, b, c, d, F4, K4, M(76) ); | |
413 | R( d, e, a, b, c, F4, K4, M(77) ); | |
414 | R( c, d, e, a, b, F4, K4, M(78) ); | |
415 | R( b, c, d, e, a, F4, K4, M(79) ); | |
416 | ||
417 | a = ctx->A += a; | |
418 | b = ctx->B += b; | |
419 | c = ctx->C += c; | |
420 | d = ctx->D += d; | |
421 | e = ctx->E += e; | |
422 | } | |
423 | } |