1 /* sha256.c - Functions to compute SHA256 and SHA224 message digest of files or
2 memory blocks according to the NIST specification FIPS-180-2.
4 Copyright (C) 2005, 2006 Free Software Foundation, Inc.
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
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.
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. */
20 /* Written by David Madore, considerably copypasting from
21 Scott G. Miller's sha1.c
34 # include "unlocked-io.h"
37 #ifdef WORDS_BIGENDIAN
41 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
44 #define BLOCKSIZE 4096
45 #if BLOCKSIZE % 64 != 0
46 # error "invalid BLOCKSIZE"
49 /* This array contains the bytes used to pad the buffer to the next
51 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
55 Takes a pointer to a 256 bit block of data (eight 32 bit ints) and
56 intializes it to the start constants of the SHA256 algorithm. This
57 must be called before using hash in the call to sha256_hash
60 sha256_init_ctx (struct sha256_ctx *ctx)
62 ctx->state[0] = 0x6a09e667UL;
63 ctx->state[1] = 0xbb67ae85UL;
64 ctx->state[2] = 0x3c6ef372UL;
65 ctx->state[3] = 0xa54ff53aUL;
66 ctx->state[4] = 0x510e527fUL;
67 ctx->state[5] = 0x9b05688cUL;
68 ctx->state[6] = 0x1f83d9abUL;
69 ctx->state[7] = 0x5be0cd19UL;
71 ctx->total[0] = ctx->total[1] = 0;
76 sha224_init_ctx (struct sha256_ctx *ctx)
78 ctx->state[0] = 0xc1059ed8UL;
79 ctx->state[1] = 0x367cd507UL;
80 ctx->state[2] = 0x3070dd17UL;
81 ctx->state[3] = 0xf70e5939UL;
82 ctx->state[4] = 0xffc00b31UL;
83 ctx->state[5] = 0x68581511UL;
84 ctx->state[6] = 0x64f98fa7UL;
85 ctx->state[7] = 0xbefa4fa4UL;
87 ctx->total[0] = ctx->total[1] = 0;
91 /* Put result from CTX in first 32 bytes following RESBUF. The result
92 must be in little endian byte order.
94 IMPORTANT: On some systems it is required that RESBUF is correctly
95 aligned for a 32-bit value. */
97 sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
101 for (i = 0; i < 8; i++)
102 ((uint32_t *) resbuf)[i] = SWAP (ctx->state[i]);
108 sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
112 for (i = 0; i < 7; i++)
113 ((uint32_t *) resbuf)[i] = SWAP (ctx->state[i]);
118 /* Process the remaining bytes in the internal buffer and the usual
119 prolog according to the standard and write the result to RESBUF.
121 IMPORTANT: On some systems it is required that RESBUF is correctly
122 aligned for a 32-bit value. */
124 sha256_conclude_ctx (struct sha256_ctx *ctx)
126 /* Take yet unprocessed bytes into account. */
127 uint32_t bytes = ctx->buflen;
128 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
130 /* Now count remaining bytes. */
131 ctx->total[0] += bytes;
132 if (ctx->total[0] < bytes)
135 /* Put the 64-bit file length in *bits* at the end of the buffer. */
136 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
137 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
139 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
141 /* Process last bytes. */
142 sha256_process_block (ctx->buffer, size * 4, ctx);
146 sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
148 sha256_conclude_ctx (ctx);
149 return sha256_read_ctx (ctx, resbuf);
153 sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
155 sha256_conclude_ctx (ctx);
156 return sha224_read_ctx (ctx, resbuf);
159 /* Compute SHA256 message digest for bytes read from STREAM. The
160 resulting message digest number will be written into the 32 bytes
161 beginning at RESBLOCK. */
163 sha256_stream (FILE *stream, void *resblock)
165 struct sha256_ctx ctx;
166 char buffer[BLOCKSIZE + 72];
169 /* Initialize the computation context. */
170 sha256_init_ctx (&ctx);
172 /* Iterate over full file contents. */
175 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
176 computation function processes the whole buffer so that with the
177 next round of the loop another block can be read. */
181 /* Read block. Take care for partial reads. */
184 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
188 if (sum == BLOCKSIZE)
193 /* Check for the error flag IFF N == 0, so that we don't
194 exit the loop after a partial read due to e.g., EAGAIN
198 goto process_partial_block;
201 /* We've read at least one byte, so ignore errors. But always
202 check for EOF, since feof may be true even though N > 0.
203 Otherwise, we could end up calling fread after EOF. */
205 goto process_partial_block;
208 /* Process buffer with BLOCKSIZE bytes. Note that
211 sha256_process_block (buffer, BLOCKSIZE, &ctx);
214 process_partial_block:;
216 /* Process any remaining bytes. */
218 sha256_process_bytes (buffer, sum, &ctx);
220 /* Construct result in desired memory. */
221 sha256_finish_ctx (&ctx, resblock);
225 /* FIXME: Avoid code duplication */
227 sha224_stream (FILE *stream, void *resblock)
229 struct sha256_ctx ctx;
230 char buffer[BLOCKSIZE + 72];
233 /* Initialize the computation context. */
234 sha224_init_ctx (&ctx);
236 /* Iterate over full file contents. */
239 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
240 computation function processes the whole buffer so that with the
241 next round of the loop another block can be read. */
245 /* Read block. Take care for partial reads. */
248 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
252 if (sum == BLOCKSIZE)
257 /* Check for the error flag IFF N == 0, so that we don't
258 exit the loop after a partial read due to e.g., EAGAIN
262 goto process_partial_block;
265 /* We've read at least one byte, so ignore errors. But always
266 check for EOF, since feof may be true even though N > 0.
267 Otherwise, we could end up calling fread after EOF. */
269 goto process_partial_block;
272 /* Process buffer with BLOCKSIZE bytes. Note that
275 sha256_process_block (buffer, BLOCKSIZE, &ctx);
278 process_partial_block:;
280 /* Process any remaining bytes. */
282 sha256_process_bytes (buffer, sum, &ctx);
284 /* Construct result in desired memory. */
285 sha224_finish_ctx (&ctx, resblock);
289 /* Compute SHA512 message digest for LEN bytes beginning at BUFFER. The
290 result is always in little endian byte order, so that a byte-wise
291 output yields to the wanted ASCII representation of the message
294 sha256_buffer (const char *buffer, size_t len, void *resblock)
296 struct sha256_ctx ctx;
298 /* Initialize the computation context. */
299 sha256_init_ctx (&ctx);
301 /* Process whole buffer but last len % 64 bytes. */
302 sha256_process_bytes (buffer, len, &ctx);
304 /* Put result in desired memory area. */
305 return sha256_finish_ctx (&ctx, resblock);
309 sha224_buffer (const char *buffer, size_t len, void *resblock)
311 struct sha256_ctx ctx;
313 /* Initialize the computation context. */
314 sha224_init_ctx (&ctx);
316 /* Process whole buffer but last len % 64 bytes. */
317 sha256_process_bytes (buffer, len, &ctx);
319 /* Put result in desired memory area. */
320 return sha224_finish_ctx (&ctx, resblock);
324 sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx)
326 /* When we already have some bits in our internal buffer concatenate
327 both inputs first. */
328 if (ctx->buflen != 0)
330 size_t left_over = ctx->buflen;
331 size_t add = 128 - left_over > len ? len : 128 - left_over;
333 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
336 if (ctx->buflen > 64)
338 sha256_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
341 /* The regions in the following copy operation cannot overlap. */
343 &((char *) ctx->buffer)[(left_over + add) & ~63],
347 buffer = (const char *) buffer + add;
351 /* Process available complete blocks. */
354 #if !_STRING_ARCH_unaligned
355 # define alignof(type) offsetof (struct { char c; type x; }, x)
356 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
357 if (UNALIGNED_P (buffer))
360 sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
361 buffer = (const char *) buffer + 64;
367 sha256_process_block (buffer, len & ~63, ctx);
368 buffer = (const char *) buffer + (len & ~63);
373 /* Move remaining bytes in internal buffer. */
376 size_t left_over = ctx->buflen;
378 memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
382 sha256_process_block (ctx->buffer, 64, ctx);
384 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
386 ctx->buflen = left_over;
390 /* --- Code below is the primary difference between sha1.c and sha256.c --- */
392 /* SHA256 round constants */
393 #define K(I) sha256_round_constants[I]
394 static const uint32_t sha256_round_constants[64] = {
395 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
396 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
397 0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
398 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
399 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
400 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
401 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
402 0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
403 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
404 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
405 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
406 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
407 0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
408 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
409 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
410 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL,
413 /* Round functions. */
414 #define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) )
415 #define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) )
417 /* Process LEN bytes of BUFFER, accumulating context into CTX.
418 It is assumed that LEN % 64 == 0.
419 Most of this code comes from GnuPG's cipher/sha1.c. */
422 sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
424 const uint32_t *words = buffer;
425 size_t nwords = len / sizeof (uint32_t);
426 const uint32_t *endp = words + nwords;
428 uint32_t a = ctx->state[0];
429 uint32_t b = ctx->state[1];
430 uint32_t c = ctx->state[2];
431 uint32_t d = ctx->state[3];
432 uint32_t e = ctx->state[4];
433 uint32_t f = ctx->state[5];
434 uint32_t g = ctx->state[6];
435 uint32_t h = ctx->state[7];
437 /* First increment the byte count. FIPS PUB 180-2 specifies the possible
438 length of the file up to 2^64 bits. Here we only compute the
439 number of bytes. Do a double word increment. */
440 ctx->total[0] += len;
441 if (ctx->total[0] < len)
444 #define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
445 #define S0(x) (rol(x,25)^rol(x,14)^(x>>3))
446 #define S1(x) (rol(x,15)^rol(x,13)^(x>>10))
447 #define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10))
448 #define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7))
450 #define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \
451 + S0(x[(I-15)&0x0f]) + x[I&0x0f] \
454 #define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \
459 D += t1; H = t0 + t1; \
467 /* FIXME: see sha1.c for a better implementation. */
468 for (t = 0; t < 16; t++)
470 x[t] = SWAP (*words);
474 R( a, b, c, d, e, f, g, h, K( 0), x[ 0] );
475 R( h, a, b, c, d, e, f, g, K( 1), x[ 1] );
476 R( g, h, a, b, c, d, e, f, K( 2), x[ 2] );
477 R( f, g, h, a, b, c, d, e, K( 3), x[ 3] );
478 R( e, f, g, h, a, b, c, d, K( 4), x[ 4] );
479 R( d, e, f, g, h, a, b, c, K( 5), x[ 5] );
480 R( c, d, e, f, g, h, a, b, K( 6), x[ 6] );
481 R( b, c, d, e, f, g, h, a, K( 7), x[ 7] );
482 R( a, b, c, d, e, f, g, h, K( 8), x[ 8] );
483 R( h, a, b, c, d, e, f, g, K( 9), x[ 9] );
484 R( g, h, a, b, c, d, e, f, K(10), x[10] );
485 R( f, g, h, a, b, c, d, e, K(11), x[11] );
486 R( e, f, g, h, a, b, c, d, K(12), x[12] );
487 R( d, e, f, g, h, a, b, c, K(13), x[13] );
488 R( c, d, e, f, g, h, a, b, K(14), x[14] );
489 R( b, c, d, e, f, g, h, a, K(15), x[15] );
490 R( a, b, c, d, e, f, g, h, K(16), M(16) );
491 R( h, a, b, c, d, e, f, g, K(17), M(17) );
492 R( g, h, a, b, c, d, e, f, K(18), M(18) );
493 R( f, g, h, a, b, c, d, e, K(19), M(19) );
494 R( e, f, g, h, a, b, c, d, K(20), M(20) );
495 R( d, e, f, g, h, a, b, c, K(21), M(21) );
496 R( c, d, e, f, g, h, a, b, K(22), M(22) );
497 R( b, c, d, e, f, g, h, a, K(23), M(23) );
498 R( a, b, c, d, e, f, g, h, K(24), M(24) );
499 R( h, a, b, c, d, e, f, g, K(25), M(25) );
500 R( g, h, a, b, c, d, e, f, K(26), M(26) );
501 R( f, g, h, a, b, c, d, e, K(27), M(27) );
502 R( e, f, g, h, a, b, c, d, K(28), M(28) );
503 R( d, e, f, g, h, a, b, c, K(29), M(29) );
504 R( c, d, e, f, g, h, a, b, K(30), M(30) );
505 R( b, c, d, e, f, g, h, a, K(31), M(31) );
506 R( a, b, c, d, e, f, g, h, K(32), M(32) );
507 R( h, a, b, c, d, e, f, g, K(33), M(33) );
508 R( g, h, a, b, c, d, e, f, K(34), M(34) );
509 R( f, g, h, a, b, c, d, e, K(35), M(35) );
510 R( e, f, g, h, a, b, c, d, K(36), M(36) );
511 R( d, e, f, g, h, a, b, c, K(37), M(37) );
512 R( c, d, e, f, g, h, a, b, K(38), M(38) );
513 R( b, c, d, e, f, g, h, a, K(39), M(39) );
514 R( a, b, c, d, e, f, g, h, K(40), M(40) );
515 R( h, a, b, c, d, e, f, g, K(41), M(41) );
516 R( g, h, a, b, c, d, e, f, K(42), M(42) );
517 R( f, g, h, a, b, c, d, e, K(43), M(43) );
518 R( e, f, g, h, a, b, c, d, K(44), M(44) );
519 R( d, e, f, g, h, a, b, c, K(45), M(45) );
520 R( c, d, e, f, g, h, a, b, K(46), M(46) );
521 R( b, c, d, e, f, g, h, a, K(47), M(47) );
522 R( a, b, c, d, e, f, g, h, K(48), M(48) );
523 R( h, a, b, c, d, e, f, g, K(49), M(49) );
524 R( g, h, a, b, c, d, e, f, K(50), M(50) );
525 R( f, g, h, a, b, c, d, e, K(51), M(51) );
526 R( e, f, g, h, a, b, c, d, K(52), M(52) );
527 R( d, e, f, g, h, a, b, c, K(53), M(53) );
528 R( c, d, e, f, g, h, a, b, K(54), M(54) );
529 R( b, c, d, e, f, g, h, a, K(55), M(55) );
530 R( a, b, c, d, e, f, g, h, K(56), M(56) );
531 R( h, a, b, c, d, e, f, g, K(57), M(57) );
532 R( g, h, a, b, c, d, e, f, K(58), M(58) );
533 R( f, g, h, a, b, c, d, e, K(59), M(59) );
534 R( e, f, g, h, a, b, c, d, K(60), M(60) );
535 R( d, e, f, g, h, a, b, c, K(61), M(61) );
536 R( c, d, e, f, g, h, a, b, K(62), M(62) );
537 R( b, c, d, e, f, g, h, a, K(63), M(63) );
539 a = ctx->state[0] += a;
540 b = ctx->state[1] += b;
541 c = ctx->state[2] += c;
542 d = ctx->state[3] += d;
543 e = ctx->state[4] += e;
544 f = ctx->state[5] += f;
545 g = ctx->state[6] += g;
546 h = ctx->state[7] += h;