1 /* sha1.c - Functions to compute SHA1 message digest of files or
2 memory blocks according to the NIST specification FIPS-180-1.
4 Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2008, 2009, 2010 Free
5 Software Foundation, Inc.
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3, or (at your option) any
10 later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
21 /* Written by Scott G. Miller
22 Credits:
23 Robert Klep <robert@ilse.nl> -- Expansion function fix
24 */
26 #include <config.h>
28 #include "sha1.h"
30 #include <stddef.h>
31 #include <stdlib.h>
32 #include <string.h>
34 #if USE_UNLOCKED_IO
35 # include "unlocked-io.h"
36 #endif
38 #ifdef WORDS_BIGENDIAN
39 # define SWAP(n) (n)
40 #else
41 # define SWAP(n) \
42 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
43 #endif
45 #define BLOCKSIZE 32768
46 #if BLOCKSIZE % 64 != 0
47 # error "invalid BLOCKSIZE"
48 #endif
50 /* This array contains the bytes used to pad the buffer to the next
51 64-byte boundary. (RFC 1321, 3.1: Step 1) */
52 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
55 /* Take a pointer to a 160 bit block of data (five 32 bit ints) and
56 initialize it to the start constants of the SHA1 algorithm. This
57 must be called before using hash in the call to sha1_hash. */
58 void
59 sha1_init_ctx (struct sha1_ctx *ctx)
60 {
61 ctx->A = 0x67452301;
62 ctx->B = 0xefcdab89;
63 ctx->C = 0x98badcfe;
64 ctx->D = 0x10325476;
65 ctx->E = 0xc3d2e1f0;
67 ctx->total[0] = ctx->total[1] = 0;
68 ctx->buflen = 0;
69 }
71 /* Copy the 4 byte value from v into the memory location pointed to by *cp,
72 If your architecture allows unaligned access this is equivalent to
73 * (uint32_t *) cp = v */
74 static inline void
75 set_uint32 (char *cp, uint32_t v)
76 {
77 memcpy (cp, &v, sizeof v);
78 }
80 /* Put result from CTX in first 20 bytes following RESBUF. The result
81 must be in little endian byte order. */
82 void *
83 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
84 {
85 char *r = resbuf;
86 set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
87 set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
88 set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
89 set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
90 set_uint32 (r + 4 * sizeof ctx->E, SWAP (ctx->E));
92 return resbuf;
93 }
95 /* Process the remaining bytes in the internal buffer and the usual
96 prolog according to the standard and write the result to RESBUF. */
97 void *
98 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
99 {
100 /* Take yet unprocessed bytes into account. */
101 uint32_t bytes = ctx->buflen;
102 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
104 /* Now count remaining bytes. */
105 ctx->total[0] += bytes;
106 if (ctx->total[0] < bytes)
107 ++ctx->total[1];
109 /* Put the 64-bit file length in *bits* at the end of the buffer. */
110 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
111 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
113 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
115 /* Process last bytes. */
116 sha1_process_block (ctx->buffer, size * 4, ctx);
118 return sha1_read_ctx (ctx, resbuf);
119 }
121 /* Compute SHA1 message digest for bytes read from STREAM. The
122 resulting message digest number will be written into the 16 bytes
123 beginning at RESBLOCK. */
124 int
125 sha1_stream (FILE *stream, void *resblock)
126 {
127 struct sha1_ctx ctx;
128 size_t sum;
130 char *buffer = malloc (BLOCKSIZE + 72);
131 if (!buffer)
132 return 1;
134 /* Initialize the computation context. */
135 sha1_init_ctx (&ctx);
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;
146 /* Read block. Take care for partial reads. */
147 while (1)
148 {
149 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
151 sum += n;
153 if (sum == BLOCKSIZE)
154 break;
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 {
163 free (buffer);
164 return 1;
165 }
166 goto process_partial_block;
167 }
169 /* We've read at least one byte, so ignore errors. But always
170 check for EOF, since feof may be true even though N > 0.
171 Otherwise, we could end up calling fread after EOF. */
172 if (feof (stream))
173 goto process_partial_block;
174 }
176 /* Process buffer with BLOCKSIZE bytes. Note that
177 BLOCKSIZE % 64 == 0
178 */
179 sha1_process_block (buffer, BLOCKSIZE, &ctx);
180 }
182 process_partial_block:;
184 /* Process any remaining bytes. */
185 if (sum > 0)
186 sha1_process_bytes (buffer, sum, &ctx);
188 /* Construct result in desired memory. */
189 sha1_finish_ctx (&ctx, resblock);
190 free (buffer);
191 return 0;
192 }
194 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The
195 result is always in little endian byte order, so that a byte-wise
196 output yields to the wanted ASCII representation of the message
197 digest. */
198 void *
199 sha1_buffer (const char *buffer, size_t len, void *resblock)
200 {
201 struct sha1_ctx ctx;
203 /* Initialize the computation context. */
204 sha1_init_ctx (&ctx);
206 /* Process whole buffer but last len % 64 bytes. */
207 sha1_process_bytes (buffer, len, &ctx);
209 /* Put result in desired memory area. */
210 return sha1_finish_ctx (&ctx, resblock);
211 }
213 void
214 sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
215 {
216 /* When we already have some bits in our internal buffer concatenate
217 both inputs first. */
218 if (ctx->buflen != 0)
219 {
220 size_t left_over = ctx->buflen;
221 size_t add = 128 - left_over > len ? len : 128 - left_over;
223 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
224 ctx->buflen += add;
226 if (ctx->buflen > 64)
227 {
228 sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
230 ctx->buflen &= 63;
231 /* The regions in the following copy operation cannot overlap. */
232 memcpy (ctx->buffer,
233 &((char *) ctx->buffer)[(left_over + add) & ~63],
234 ctx->buflen);
235 }
237 buffer = (const char *) buffer + add;
238 len -= add;
239 }
241 /* Process available complete blocks. */
242 if (len >= 64)
243 {
244 #if !_STRING_ARCH_unaligned
245 # define alignof(type) offsetof (struct { char c; type x; }, x)
246 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
247 if (UNALIGNED_P (buffer))
248 while (len > 64)
249 {
250 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
251 buffer = (const char *) buffer + 64;
252 len -= 64;
253 }
254 else
255 #endif
256 {
257 sha1_process_block (buffer, len & ~63, ctx);
258 buffer = (const char *) buffer + (len & ~63);
259 len &= 63;
260 }
261 }
263 /* Move remaining bytes in internal buffer. */
264 if (len > 0)
265 {
266 size_t left_over = ctx->buflen;
268 memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
269 left_over += len;
270 if (left_over >= 64)
271 {
272 sha1_process_block (ctx->buffer, 64, ctx);
273 left_over -= 64;
274 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
275 }
276 ctx->buflen = left_over;
277 }
278 }
280 /* --- Code below is the primary difference between md5.c and sha1.c --- */
282 /* SHA1 round constants */
283 #define K1 0x5a827999
284 #define K2 0x6ed9eba1
285 #define K3 0x8f1bbcdc
286 #define K4 0xca62c1d6
288 /* Round functions. Note that F2 is the same as F4. */
289 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
290 #define F2(B,C,D) (B ^ C ^ D)
291 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
292 #define F4(B,C,D) (B ^ C ^ D)
294 /* Process LEN bytes of BUFFER, accumulating context into CTX.
295 It is assumed that LEN % 64 == 0.
296 Most of this code comes from GnuPG's cipher/sha1.c. */
298 void
299 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
300 {
301 const uint32_t *words = buffer;
302 size_t nwords = len / sizeof (uint32_t);
303 const uint32_t *endp = words + nwords;
304 uint32_t x[16];
305 uint32_t a = ctx->A;
306 uint32_t b = ctx->B;
307 uint32_t c = ctx->C;
308 uint32_t d = ctx->D;
309 uint32_t e = ctx->E;
311 /* First increment the byte count. RFC 1321 specifies the possible
312 length of the file up to 2^64 bits. Here we only compute the
313 number of bytes. Do a double word increment. */
314 ctx->total[0] += len;
315 if (ctx->total[0] < len)
316 ++ctx->total[1];
318 #define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
320 #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \
321 ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
322 , (x[I&0x0f] = rol(tm, 1)) )
324 #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \
325 + F( B, C, D ) \
326 + K \
327 + M; \
328 B = rol( B, 30 ); \
329 } while(0)
331 while (words < endp)
332 {
333 uint32_t tm;
334 int t;
335 for (t = 0; t < 16; t++)
336 {
337 x[t] = SWAP (*words);
338 words++;
339 }
341 R( a, b, c, d, e, F1, K1, x[ 0] );
342 R( e, a, b, c, d, F1, K1, x[ 1] );
343 R( d, e, a, b, c, F1, K1, x[ 2] );
344 R( c, d, e, a, b, F1, K1, x[ 3] );
345 R( b, c, d, e, a, F1, K1, x[ 4] );
346 R( a, b, c, d, e, F1, K1, x[ 5] );
347 R( e, a, b, c, d, F1, K1, x[ 6] );
348 R( d, e, a, b, c, F1, K1, x[ 7] );
349 R( c, d, e, a, b, F1, K1, x[ 8] );
350 R( b, c, d, e, a, F1, K1, x[ 9] );
351 R( a, b, c, d, e, F1, K1, x[10] );
352 R( e, a, b, c, d, F1, K1, x[11] );
353 R( d, e, a, b, c, F1, K1, x[12] );
354 R( c, d, e, a, b, F1, K1, x[13] );
355 R( b, c, d, e, a, F1, K1, x[14] );
356 R( a, b, c, d, e, F1, K1, x[15] );
357 R( e, a, b, c, d, F1, K1, M(16) );
358 R( d, e, a, b, c, F1, K1, M(17) );
359 R( c, d, e, a, b, F1, K1, M(18) );
360 R( b, c, d, e, a, F1, K1, M(19) );
361 R( a, b, c, d, e, F2, K2, M(20) );
362 R( e, a, b, c, d, F2, K2, M(21) );
363 R( d, e, a, b, c, F2, K2, M(22) );
364 R( c, d, e, a, b, F2, K2, M(23) );
365 R( b, c, d, e, a, F2, K2, M(24) );
366 R( a, b, c, d, e, F2, K2, M(25) );
367 R( e, a, b, c, d, F2, K2, M(26) );
368 R( d, e, a, b, c, F2, K2, M(27) );
369 R( c, d, e, a, b, F2, K2, M(28) );
370 R( b, c, d, e, a, F2, K2, M(29) );
371 R( a, b, c, d, e, F2, K2, M(30) );
372 R( e, a, b, c, d, F2, K2, M(31) );
373 R( d, e, a, b, c, F2, K2, M(32) );
374 R( c, d, e, a, b, F2, K2, M(33) );
375 R( b, c, d, e, a, F2, K2, M(34) );
376 R( a, b, c, d, e, F2, K2, M(35) );
377 R( e, a, b, c, d, F2, K2, M(36) );
378 R( d, e, a, b, c, F2, K2, M(37) );
379 R( c, d, e, a, b, F2, K2, M(38) );
380 R( b, c, d, e, a, F2, K2, M(39) );
381 R( a, b, c, d, e, F3, K3, M(40) );
382 R( e, a, b, c, d, F3, K3, M(41) );
383 R( d, e, a, b, c, F3, K3, M(42) );
384 R( c, d, e, a, b, F3, K3, M(43) );
385 R( b, c, d, e, a, F3, K3, M(44) );
386 R( a, b, c, d, e, F3, K3, M(45) );
387 R( e, a, b, c, d, F3, K3, M(46) );
388 R( d, e, a, b, c, F3, K3, M(47) );
389 R( c, d, e, a, b, F3, K3, M(48) );
390 R( b, c, d, e, a, F3, K3, M(49) );
391 R( a, b, c, d, e, F3, K3, M(50) );
392 R( e, a, b, c, d, F3, K3, M(51) );
393 R( d, e, a, b, c, F3, K3, M(52) );
394 R( c, d, e, a, b, F3, K3, M(53) );
395 R( b, c, d, e, a, F3, K3, M(54) );
396 R( a, b, c, d, e, F3, K3, M(55) );
397 R( e, a, b, c, d, F3, K3, M(56) );
398 R( d, e, a, b, c, F3, K3, M(57) );
399 R( c, d, e, a, b, F3, K3, M(58) );
400 R( b, c, d, e, a, F3, K3, M(59) );
401 R( a, b, c, d, e, F4, K4, M(60) );
402 R( e, a, b, c, d, F4, K4, M(61) );
403 R( d, e, a, b, c, F4, K4, M(62) );
404 R( c, d, e, a, b, F4, K4, M(63) );
405 R( b, c, d, e, a, F4, K4, M(64) );
406 R( a, b, c, d, e, F4, K4, M(65) );
407 R( e, a, b, c, d, F4, K4, M(66) );
408 R( d, e, a, b, c, F4, K4, M(67) );
409 R( c, d, e, a, b, F4, K4, M(68) );
410 R( b, c, d, e, a, F4, K4, M(69) );
411 R( a, b, c, d, e, F4, K4, M(70) );
412 R( e, a, b, c, d, F4, K4, M(71) );
413 R( d, e, a, b, c, F4, K4, M(72) );
414 R( c, d, e, a, b, F4, K4, M(73) );
415 R( b, c, d, e, a, F4, K4, M(74) );
416 R( a, b, c, d, e, F4, K4, M(75) );
417 R( e, a, b, c, d, F4, K4, M(76) );
418 R( d, e, a, b, c, F4, K4, M(77) );
419 R( c, d, e, a, b, F4, K4, M(78) );
420 R( b, c, d, e, a, F4, K4, M(79) );
422 a = ctx->A += a;
423 b = ctx->B += b;
424 c = ctx->C += c;
425 d = ctx->D += d;
426 e = ctx->E += e;
427 }
428 }