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[binutils.git] / ld / sha1.c
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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) 2007 Free Software Foundation, Inc.
6 This file is part of the GNU Binutils.
8 This program is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 3, or (at your option) any
11 later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software Foundation,
20 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
22 /* Written by Scott G. Miller
23 Credits:
24 Robert Klep <robert@ilse.nl> -- Expansion function fix */
26 #include <config.h>
27 #include "sha1.h"
28 #include <stddef.h>
29 #include <string.h>
31 #if USE_UNLOCKED_IO
32 # include "unlocked-io.h"
33 #endif
35 #ifdef WORDS_BIGENDIAN
36 # define SWAP(n) (n)
37 #else
38 # define SWAP(n) \
39 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
40 #endif
42 #define BLOCKSIZE 4096
43 #if BLOCKSIZE % 64 != 0
44 # error "invalid BLOCKSIZE"
45 #endif
47 /* This array contains the bytes used to pad the buffer to the next
48 64-byte boundary. (RFC 1321, 3.1: Step 1) */
49 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
52 /* Take a pointer to a 160 bit block of data (five 32 bit ints) and
53 initialize it to the start constants of the SHA1 algorithm. This
54 must be called before using hash in the call to sha1_hash. */
56 void
57 sha1_init_ctx (struct sha1_ctx *ctx)
59 ctx->A = 0x67452301;
60 ctx->B = 0xefcdab89;
61 ctx->C = 0x98badcfe;
62 ctx->D = 0x10325476;
63 ctx->E = 0xc3d2e1f0;
65 ctx->total[0] = ctx->total[1] = 0;
66 ctx->buflen = 0;
69 /* Put result from CTX in first 20 bytes following RESBUF. The result
70 must be in little endian byte order.
72 IMPORTANT: On some systems it is required that RESBUF is correctly
73 aligned for a 32-bit value. */
75 void *
76 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
78 ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
79 ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
80 ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
81 ((uint32_t *) resbuf)[3] = SWAP (ctx->D);
82 ((uint32_t *) resbuf)[4] = SWAP (ctx->E);
84 return resbuf;
87 /* Process the remaining bytes in the internal buffer and the usual
88 prolog according to the standard and write the result to RESBUF.
90 IMPORTANT: On some systems it is required that RESBUF is correctly
91 aligned for a 32-bit value. */
93 void *
94 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
96 /* Take yet unprocessed bytes into account. */
97 uint32_t bytes = ctx->buflen;
98 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
100 /* Now count remaining bytes. */
101 ctx->total[0] += bytes;
102 if (ctx->total[0] < bytes)
103 ++ctx->total[1];
105 /* Put the 64-bit file length in *bits* at the end of the buffer. */
106 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
107 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
109 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
111 /* Process last bytes. */
112 sha1_process_block (ctx->buffer, size * 4, ctx);
114 return sha1_read_ctx (ctx, resbuf);
117 /* Compute SHA1 message digest for bytes read from STREAM. The
118 resulting message digest number will be written into the 16 bytes
119 beginning at RESBLOCK. */
122 sha1_stream (FILE *stream, void *resblock)
124 struct sha1_ctx ctx;
125 char buffer[BLOCKSIZE + 72];
126 size_t sum;
128 /* Initialize the computation context. */
129 sha1_init_ctx (&ctx);
131 /* Iterate over full file contents. */
132 while (1)
134 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
135 computation function processes the whole buffer so that with the
136 next round of the loop another block can be read. */
137 size_t n;
138 sum = 0;
140 /* Read block. Take care for partial reads. */
141 while (1)
143 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
145 sum += n;
147 if (sum == BLOCKSIZE)
148 break;
150 if (n == 0)
152 /* Check for the error flag IFF N == 0, so that we don't
153 exit the loop after a partial read due to e.g., EAGAIN
154 or EWOULDBLOCK. */
155 if (ferror (stream))
156 return 1;
157 goto process_partial_block;
160 /* We've read at least one byte, so ignore errors. But always
161 check for EOF, since feof may be true even though N > 0.
162 Otherwise, we could end up calling fread after EOF. */
163 if (feof (stream))
164 goto process_partial_block;
167 /* Process buffer with BLOCKSIZE bytes. Note that
168 BLOCKSIZE % 64 == 0. */
169 sha1_process_block (buffer, BLOCKSIZE, &ctx);
172 process_partial_block:;
174 /* Process any remaining bytes. */
175 if (sum > 0)
176 sha1_process_bytes (buffer, sum, &ctx);
178 /* Construct result in desired memory. */
179 sha1_finish_ctx (&ctx, resblock);
180 return 0;
183 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The
184 result is always in little endian byte order, so that a byte-wise
185 output yields to the wanted ASCII representation of the message
186 digest. */
188 void *
189 sha1_buffer (const char *buffer, size_t len, void *resblock)
191 struct sha1_ctx ctx;
193 /* Initialize the computation context. */
194 sha1_init_ctx (&ctx);
196 /* Process whole buffer but last len % 64 bytes. */
197 sha1_process_bytes (buffer, len, &ctx);
199 /* Put result in desired memory area. */
200 return sha1_finish_ctx (&ctx, resblock);
203 void
204 sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
206 /* When we already have some bits in our internal buffer concatenate
207 both inputs first. */
208 if (ctx->buflen != 0)
210 size_t left_over = ctx->buflen;
211 size_t add = 128 - left_over > len ? len : 128 - left_over;
213 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
214 ctx->buflen += add;
216 if (ctx->buflen > 64)
218 sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
220 ctx->buflen &= 63;
221 /* The regions in the following copy operation cannot overlap. */
222 memcpy (ctx->buffer,
223 &((char *) ctx->buffer)[(left_over + add) & ~63],
224 ctx->buflen);
227 buffer = (const char *) buffer + add;
228 len -= add;
231 /* Process available complete blocks. */
232 if (len >= 64)
234 #if !_STRING_ARCH_unaligned
235 # define alignof(type) offsetof (struct { char c; type x; }, x)
236 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
237 if (UNALIGNED_P (buffer))
238 while (len > 64)
240 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
241 buffer = (const char *) buffer + 64;
242 len -= 64;
244 else
245 #endif
247 sha1_process_block (buffer, len & ~63, ctx);
248 buffer = (const char *) buffer + (len & ~63);
249 len &= 63;
253 /* Move remaining bytes in internal buffer. */
254 if (len > 0)
256 size_t left_over = ctx->buflen;
258 memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
259 left_over += len;
260 if (left_over >= 64)
262 sha1_process_block (ctx->buffer, 64, ctx);
263 left_over -= 64;
264 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
266 ctx->buflen = left_over;
270 /* --- Code below is the primary difference between md5.c and sha1.c --- */
272 /* SHA1 round constants. */
273 #define K1 0x5a827999
274 #define K2 0x6ed9eba1
275 #define K3 0x8f1bbcdc
276 #define K4 0xca62c1d6
278 /* Round functions. Note that F2 is the same as F4. */
279 #define F1(B,C,D) (D ^ (B & (C ^ D)))
280 #define F2(B,C,D) (B ^ C ^ D)
281 #define F3(B,C,D) ((B & C) | (D & (B | C)))
282 #define F4(B,C,D) (B ^ C ^ D)
284 /* Process LEN bytes of BUFFER, accumulating context into CTX.
285 It is assumed that LEN % 64 == 0.
286 Most of this code comes from GnuPG's cipher/sha1.c. */
288 void
289 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
291 const uint32_t *words = buffer;
292 size_t nwords = len / sizeof (uint32_t);
293 const uint32_t *endp = words + nwords;
294 uint32_t x[16];
295 uint32_t a = ctx->A;
296 uint32_t b = ctx->B;
297 uint32_t c = ctx->C;
298 uint32_t d = ctx->D;
299 uint32_t e = ctx->E;
301 /* First increment the byte count. RFC 1321 specifies the possible
302 length of the file up to 2^64 bits. Here we only compute the
303 number of bytes. Do a double word increment. */
304 ctx->total[0] += len;
305 if (ctx->total[0] < len)
306 ++ctx->total[1];
308 #define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
310 #define M(I) (tm = x[I & 0x0f] ^ x[(I - 14) & 0x0f] \
311 ^ x[(I - 8) & 0x0f] ^ x[(I - 3) & 0x0f] \
312 , (x[I & 0x0f] = rol (tm, 1)))
314 #define R(A,B,C,D,E,F,K,M) \
315 do \
317 E += rol (A, 5) \
318 + F (B, C, D) \
319 + K \
320 + M; \
321 B = rol (B, 30); \
323 while (0)
325 while (words < endp)
327 uint32_t tm;
328 int t;
330 for (t = 0; t < 16; t++)
332 x[t] = SWAP (*words);
333 words++;
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));
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;