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, 2008 Free Software Foundation, Inc.
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
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, see <http://www.gnu.org/licenses/>. */
19 /* Written by David Madore, considerably copypasting from
20 Scott G. Miller's sha1.c
31 # include "unlocked-io.h"
34 #ifdef WORDS_BIGENDIAN
38 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
41 #define BLOCKSIZE 4096
42 #if BLOCKSIZE % 64 != 0
43 # error "invalid BLOCKSIZE"
46 /* This array contains the bytes used to pad the buffer to the next
48 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
52 Takes a pointer to a 256 bit block of data (eight 32 bit ints) and
53 intializes it to the start constants of the SHA256 algorithm. This
54 must be called before using hash in the call to sha256_hash
57 sha256_init_ctx (struct sha256_ctx *ctx)
59 ctx->state[0] = 0x6a09e667UL;
60 ctx->state[1] = 0xbb67ae85UL;
61 ctx->state[2] = 0x3c6ef372UL;
62 ctx->state[3] = 0xa54ff53aUL;
63 ctx->state[4] = 0x510e527fUL;
64 ctx->state[5] = 0x9b05688cUL;
65 ctx->state[6] = 0x1f83d9abUL;
66 ctx->state[7] = 0x5be0cd19UL;
68 ctx->total[0] = ctx->total[1] = 0;
73 sha224_init_ctx (struct sha256_ctx *ctx)
75 ctx->state[0] = 0xc1059ed8UL;
76 ctx->state[1] = 0x367cd507UL;
77 ctx->state[2] = 0x3070dd17UL;
78 ctx->state[3] = 0xf70e5939UL;
79 ctx->state[4] = 0xffc00b31UL;
80 ctx->state[5] = 0x68581511UL;
81 ctx->state[6] = 0x64f98fa7UL;
82 ctx->state[7] = 0xbefa4fa4UL;
84 ctx->total[0] = ctx->total[1] = 0;
88 /* Copy the value from v into the memory location pointed to by *cp,
89 If your architecture allows unaligned access this is equivalent to
90 * (uint32_t *) cp = v */
92 set_uint32 (char *cp, uint32_t v)
94 memcpy (cp, &v, sizeof v);
97 /* Put result from CTX in first 32 bytes following RESBUF. The result
98 must be in little endian byte order. */
100 sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
105 for (i = 0; i < 8; i++)
106 set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i]));
112 sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf)
117 for (i = 0; i < 7; i++)
118 set_uint32 (r + i * sizeof ctx->state[0], SWAP (ctx->state[i]));
123 /* Process the remaining bytes in the internal buffer and the usual
124 prolog according to the standard and write the result to RESBUF. */
126 sha256_conclude_ctx (struct sha256_ctx *ctx)
128 /* Take yet unprocessed bytes into account. */
129 size_t bytes = ctx->buflen;
130 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
132 /* Now count remaining bytes. */
133 ctx->total[0] += bytes;
134 if (ctx->total[0] < bytes)
137 /* Put the 64-bit file length in *bits* at the end of the buffer.
138 Use set_uint32 rather than a simple assignment, to avoid risk of
140 set_uint32 ((char *) &ctx->buffer[size - 2],
141 SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)));
142 set_uint32 ((char *) &ctx->buffer[size - 1],
143 SWAP (ctx->total[0] << 3));
145 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
147 /* Process last bytes. */
148 sha256_process_block (ctx->buffer, size * 4, ctx);
152 sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
154 sha256_conclude_ctx (ctx);
155 return sha256_read_ctx (ctx, resbuf);
159 sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
161 sha256_conclude_ctx (ctx);
162 return sha224_read_ctx (ctx, resbuf);
165 /* Compute SHA256 message digest for bytes read from STREAM. The
166 resulting message digest number will be written into the 32 bytes
167 beginning at RESBLOCK. */
169 sha256_stream (FILE *stream, void *resblock)
171 struct sha256_ctx ctx;
172 char buffer[BLOCKSIZE + 72];
175 /* Initialize the computation context. */
176 sha256_init_ctx (&ctx);
178 /* Iterate over full file contents. */
181 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
182 computation function processes the whole buffer so that with the
183 next round of the loop another block can be read. */
187 /* Read block. Take care for partial reads. */
190 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
194 if (sum == BLOCKSIZE)
199 /* Check for the error flag IFF N == 0, so that we don't
200 exit the loop after a partial read due to e.g., EAGAIN
204 goto process_partial_block;
207 /* We've read at least one byte, so ignore errors. But always
208 check for EOF, since feof may be true even though N > 0.
209 Otherwise, we could end up calling fread after EOF. */
211 goto process_partial_block;
214 /* Process buffer with BLOCKSIZE bytes. Note that
217 sha256_process_block (buffer, BLOCKSIZE, &ctx);
220 process_partial_block:;
222 /* Process any remaining bytes. */
224 sha256_process_bytes (buffer, sum, &ctx);
226 /* Construct result in desired memory. */
227 sha256_finish_ctx (&ctx, resblock);
231 /* FIXME: Avoid code duplication */
233 sha224_stream (FILE *stream, void *resblock)
235 struct sha256_ctx ctx;
236 char buffer[BLOCKSIZE + 72];
239 /* Initialize the computation context. */
240 sha224_init_ctx (&ctx);
242 /* Iterate over full file contents. */
245 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
246 computation function processes the whole buffer so that with the
247 next round of the loop another block can be read. */
251 /* Read block. Take care for partial reads. */
254 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
258 if (sum == BLOCKSIZE)
263 /* Check for the error flag IFF N == 0, so that we don't
264 exit the loop after a partial read due to e.g., EAGAIN
268 goto process_partial_block;
271 /* We've read at least one byte, so ignore errors. But always
272 check for EOF, since feof may be true even though N > 0.
273 Otherwise, we could end up calling fread after EOF. */
275 goto process_partial_block;
278 /* Process buffer with BLOCKSIZE bytes. Note that
281 sha256_process_block (buffer, BLOCKSIZE, &ctx);
284 process_partial_block:;
286 /* Process any remaining bytes. */
288 sha256_process_bytes (buffer, sum, &ctx);
290 /* Construct result in desired memory. */
291 sha224_finish_ctx (&ctx, resblock);
295 /* Compute SHA512 message digest for LEN bytes beginning at BUFFER. The
296 result is always in little endian byte order, so that a byte-wise
297 output yields to the wanted ASCII representation of the message
300 sha256_buffer (const char *buffer, size_t len, void *resblock)
302 struct sha256_ctx ctx;
304 /* Initialize the computation context. */
305 sha256_init_ctx (&ctx);
307 /* Process whole buffer but last len % 64 bytes. */
308 sha256_process_bytes (buffer, len, &ctx);
310 /* Put result in desired memory area. */
311 return sha256_finish_ctx (&ctx, resblock);
315 sha224_buffer (const char *buffer, size_t len, void *resblock)
317 struct sha256_ctx ctx;
319 /* Initialize the computation context. */
320 sha224_init_ctx (&ctx);
322 /* Process whole buffer but last len % 64 bytes. */
323 sha256_process_bytes (buffer, len, &ctx);
325 /* Put result in desired memory area. */
326 return sha224_finish_ctx (&ctx, resblock);
330 sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx)
332 /* When we already have some bits in our internal buffer concatenate
333 both inputs first. */
334 if (ctx->buflen != 0)
336 size_t left_over = ctx->buflen;
337 size_t add = 128 - left_over > len ? len : 128 - left_over;
339 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
342 if (ctx->buflen > 64)
344 sha256_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
347 /* The regions in the following copy operation cannot overlap. */
349 &((char *) ctx->buffer)[(left_over + add) & ~63],
353 buffer = (const char *) buffer + add;
357 /* Process available complete blocks. */
360 #if !_STRING_ARCH_unaligned
361 # define alignof(type) offsetof (struct { char c; type x; }, x)
362 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
363 if (UNALIGNED_P (buffer))
366 sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
367 buffer = (const char *) buffer + 64;
373 sha256_process_block (buffer, len & ~63, ctx);
374 buffer = (const char *) buffer + (len & ~63);
379 /* Move remaining bytes in internal buffer. */
382 size_t left_over = ctx->buflen;
384 memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
388 sha256_process_block (ctx->buffer, 64, ctx);
390 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
392 ctx->buflen = left_over;
396 /* --- Code below is the primary difference between sha1.c and sha256.c --- */
398 /* SHA256 round constants */
399 #define K(I) sha256_round_constants[I]
400 static const uint32_t sha256_round_constants[64] = {
401 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
402 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
403 0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
404 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
405 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
406 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
407 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
408 0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
409 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
410 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
411 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
412 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
413 0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
414 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
415 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
416 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL,
419 /* Round functions. */
420 #define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) )
421 #define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) )
423 /* Process LEN bytes of BUFFER, accumulating context into CTX.
424 It is assumed that LEN % 64 == 0.
425 Most of this code comes from GnuPG's cipher/sha1.c. */
428 sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
430 const uint32_t *words = buffer;
431 size_t nwords = len / sizeof (uint32_t);
432 const uint32_t *endp = words + nwords;
434 uint32_t a = ctx->state[0];
435 uint32_t b = ctx->state[1];
436 uint32_t c = ctx->state[2];
437 uint32_t d = ctx->state[3];
438 uint32_t e = ctx->state[4];
439 uint32_t f = ctx->state[5];
440 uint32_t g = ctx->state[6];
441 uint32_t h = ctx->state[7];
443 /* First increment the byte count. FIPS PUB 180-2 specifies the possible
444 length of the file up to 2^64 bits. Here we only compute the
445 number of bytes. Do a double word increment. */
446 ctx->total[0] += len;
447 if (ctx->total[0] < len)
450 #define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
451 #define S0(x) (rol(x,25)^rol(x,14)^(x>>3))
452 #define S1(x) (rol(x,15)^rol(x,13)^(x>>10))
453 #define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10))
454 #define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7))
456 #define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \
457 + S0(x[(I-15)&0x0f]) + x[I&0x0f] \
460 #define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \
465 D += t1; H = t0 + t1; \
473 /* FIXME: see sha1.c for a better implementation. */
474 for (t = 0; t < 16; t++)
476 x[t] = SWAP (*words);
480 R( a, b, c, d, e, f, g, h, K( 0), x[ 0] );
481 R( h, a, b, c, d, e, f, g, K( 1), x[ 1] );
482 R( g, h, a, b, c, d, e, f, K( 2), x[ 2] );
483 R( f, g, h, a, b, c, d, e, K( 3), x[ 3] );
484 R( e, f, g, h, a, b, c, d, K( 4), x[ 4] );
485 R( d, e, f, g, h, a, b, c, K( 5), x[ 5] );
486 R( c, d, e, f, g, h, a, b, K( 6), x[ 6] );
487 R( b, c, d, e, f, g, h, a, K( 7), x[ 7] );
488 R( a, b, c, d, e, f, g, h, K( 8), x[ 8] );
489 R( h, a, b, c, d, e, f, g, K( 9), x[ 9] );
490 R( g, h, a, b, c, d, e, f, K(10), x[10] );
491 R( f, g, h, a, b, c, d, e, K(11), x[11] );
492 R( e, f, g, h, a, b, c, d, K(12), x[12] );
493 R( d, e, f, g, h, a, b, c, K(13), x[13] );
494 R( c, d, e, f, g, h, a, b, K(14), x[14] );
495 R( b, c, d, e, f, g, h, a, K(15), x[15] );
496 R( a, b, c, d, e, f, g, h, K(16), M(16) );
497 R( h, a, b, c, d, e, f, g, K(17), M(17) );
498 R( g, h, a, b, c, d, e, f, K(18), M(18) );
499 R( f, g, h, a, b, c, d, e, K(19), M(19) );
500 R( e, f, g, h, a, b, c, d, K(20), M(20) );
501 R( d, e, f, g, h, a, b, c, K(21), M(21) );
502 R( c, d, e, f, g, h, a, b, K(22), M(22) );
503 R( b, c, d, e, f, g, h, a, K(23), M(23) );
504 R( a, b, c, d, e, f, g, h, K(24), M(24) );
505 R( h, a, b, c, d, e, f, g, K(25), M(25) );
506 R( g, h, a, b, c, d, e, f, K(26), M(26) );
507 R( f, g, h, a, b, c, d, e, K(27), M(27) );
508 R( e, f, g, h, a, b, c, d, K(28), M(28) );
509 R( d, e, f, g, h, a, b, c, K(29), M(29) );
510 R( c, d, e, f, g, h, a, b, K(30), M(30) );
511 R( b, c, d, e, f, g, h, a, K(31), M(31) );
512 R( a, b, c, d, e, f, g, h, K(32), M(32) );
513 R( h, a, b, c, d, e, f, g, K(33), M(33) );
514 R( g, h, a, b, c, d, e, f, K(34), M(34) );
515 R( f, g, h, a, b, c, d, e, K(35), M(35) );
516 R( e, f, g, h, a, b, c, d, K(36), M(36) );
517 R( d, e, f, g, h, a, b, c, K(37), M(37) );
518 R( c, d, e, f, g, h, a, b, K(38), M(38) );
519 R( b, c, d, e, f, g, h, a, K(39), M(39) );
520 R( a, b, c, d, e, f, g, h, K(40), M(40) );
521 R( h, a, b, c, d, e, f, g, K(41), M(41) );
522 R( g, h, a, b, c, d, e, f, K(42), M(42) );
523 R( f, g, h, a, b, c, d, e, K(43), M(43) );
524 R( e, f, g, h, a, b, c, d, K(44), M(44) );
525 R( d, e, f, g, h, a, b, c, K(45), M(45) );
526 R( c, d, e, f, g, h, a, b, K(46), M(46) );
527 R( b, c, d, e, f, g, h, a, K(47), M(47) );
528 R( a, b, c, d, e, f, g, h, K(48), M(48) );
529 R( h, a, b, c, d, e, f, g, K(49), M(49) );
530 R( g, h, a, b, c, d, e, f, K(50), M(50) );
531 R( f, g, h, a, b, c, d, e, K(51), M(51) );
532 R( e, f, g, h, a, b, c, d, K(52), M(52) );
533 R( d, e, f, g, h, a, b, c, K(53), M(53) );
534 R( c, d, e, f, g, h, a, b, K(54), M(54) );
535 R( b, c, d, e, f, g, h, a, K(55), M(55) );
536 R( a, b, c, d, e, f, g, h, K(56), M(56) );
537 R( h, a, b, c, d, e, f, g, K(57), M(57) );
538 R( g, h, a, b, c, d, e, f, K(58), M(58) );
539 R( f, g, h, a, b, c, d, e, K(59), M(59) );
540 R( e, f, g, h, a, b, c, d, K(60), M(60) );
541 R( d, e, f, g, h, a, b, c, K(61), M(61) );
542 R( c, d, e, f, g, h, a, b, K(62), M(62) );
543 R( b, c, d, e, f, g, h, a, K(63), M(63) );
545 a = ctx->state[0] += a;
546 b = ctx->state[1] += b;
547 c = ctx->state[2] += c;
548 d = ctx->state[3] += d;
549 e = ctx->state[4] += e;
550 f = ctx->state[5] += f;
551 g = ctx->state[6] += g;
552 h = ctx->state[7] += h;