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 uint32_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 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
139 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
141 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
143 /* Process last bytes. */
144 sha256_process_block (ctx->buffer, size * 4, ctx);
148 sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
150 sha256_conclude_ctx (ctx);
151 return sha256_read_ctx (ctx, resbuf);
155 sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
157 sha256_conclude_ctx (ctx);
158 return sha224_read_ctx (ctx, resbuf);
161 /* Compute SHA256 message digest for bytes read from STREAM. The
162 resulting message digest number will be written into the 32 bytes
163 beginning at RESBLOCK. */
165 sha256_stream (FILE *stream, void *resblock)
167 struct sha256_ctx ctx;
168 char buffer[BLOCKSIZE + 72];
171 /* Initialize the computation context. */
172 sha256_init_ctx (&ctx);
174 /* Iterate over full file contents. */
177 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
178 computation function processes the whole buffer so that with the
179 next round of the loop another block can be read. */
183 /* Read block. Take care for partial reads. */
186 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
190 if (sum == BLOCKSIZE)
195 /* Check for the error flag IFF N == 0, so that we don't
196 exit the loop after a partial read due to e.g., EAGAIN
200 goto process_partial_block;
203 /* We've read at least one byte, so ignore errors. But always
204 check for EOF, since feof may be true even though N > 0.
205 Otherwise, we could end up calling fread after EOF. */
207 goto process_partial_block;
210 /* Process buffer with BLOCKSIZE bytes. Note that
213 sha256_process_block (buffer, BLOCKSIZE, &ctx);
216 process_partial_block:;
218 /* Process any remaining bytes. */
220 sha256_process_bytes (buffer, sum, &ctx);
222 /* Construct result in desired memory. */
223 sha256_finish_ctx (&ctx, resblock);
227 /* FIXME: Avoid code duplication */
229 sha224_stream (FILE *stream, void *resblock)
231 struct sha256_ctx ctx;
232 char buffer[BLOCKSIZE + 72];
235 /* Initialize the computation context. */
236 sha224_init_ctx (&ctx);
238 /* Iterate over full file contents. */
241 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
242 computation function processes the whole buffer so that with the
243 next round of the loop another block can be read. */
247 /* Read block. Take care for partial reads. */
250 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
254 if (sum == BLOCKSIZE)
259 /* Check for the error flag IFF N == 0, so that we don't
260 exit the loop after a partial read due to e.g., EAGAIN
264 goto process_partial_block;
267 /* We've read at least one byte, so ignore errors. But always
268 check for EOF, since feof may be true even though N > 0.
269 Otherwise, we could end up calling fread after EOF. */
271 goto process_partial_block;
274 /* Process buffer with BLOCKSIZE bytes. Note that
277 sha256_process_block (buffer, BLOCKSIZE, &ctx);
280 process_partial_block:;
282 /* Process any remaining bytes. */
284 sha256_process_bytes (buffer, sum, &ctx);
286 /* Construct result in desired memory. */
287 sha224_finish_ctx (&ctx, resblock);
291 /* Compute SHA512 message digest for LEN bytes beginning at BUFFER. The
292 result is always in little endian byte order, so that a byte-wise
293 output yields to the wanted ASCII representation of the message
296 sha256_buffer (const char *buffer, size_t len, void *resblock)
298 struct sha256_ctx ctx;
300 /* Initialize the computation context. */
301 sha256_init_ctx (&ctx);
303 /* Process whole buffer but last len % 64 bytes. */
304 sha256_process_bytes (buffer, len, &ctx);
306 /* Put result in desired memory area. */
307 return sha256_finish_ctx (&ctx, resblock);
311 sha224_buffer (const char *buffer, size_t len, void *resblock)
313 struct sha256_ctx ctx;
315 /* Initialize the computation context. */
316 sha224_init_ctx (&ctx);
318 /* Process whole buffer but last len % 64 bytes. */
319 sha256_process_bytes (buffer, len, &ctx);
321 /* Put result in desired memory area. */
322 return sha224_finish_ctx (&ctx, resblock);
326 sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx)
328 /* When we already have some bits in our internal buffer concatenate
329 both inputs first. */
330 if (ctx->buflen != 0)
332 size_t left_over = ctx->buflen;
333 size_t add = 128 - left_over > len ? len : 128 - left_over;
335 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
338 if (ctx->buflen > 64)
340 sha256_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
343 /* The regions in the following copy operation cannot overlap. */
345 &((char *) ctx->buffer)[(left_over + add) & ~63],
349 buffer = (const char *) buffer + add;
353 /* Process available complete blocks. */
356 #if !_STRING_ARCH_unaligned
357 # define alignof(type) offsetof (struct { char c; type x; }, x)
358 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
359 if (UNALIGNED_P (buffer))
362 sha256_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
363 buffer = (const char *) buffer + 64;
369 sha256_process_block (buffer, len & ~63, ctx);
370 buffer = (const char *) buffer + (len & ~63);
375 /* Move remaining bytes in internal buffer. */
378 size_t left_over = ctx->buflen;
380 memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
384 sha256_process_block (ctx->buffer, 64, ctx);
386 memcpy (ctx->buffer, &ctx->buffer[16], left_over);
388 ctx->buflen = left_over;
392 /* --- Code below is the primary difference between sha1.c and sha256.c --- */
394 /* SHA256 round constants */
395 #define K(I) sha256_round_constants[I]
396 static const uint32_t sha256_round_constants[64] = {
397 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
398 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
399 0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
400 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
401 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
402 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
403 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
404 0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
405 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
406 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
407 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
408 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
409 0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
410 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
411 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
412 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL,
415 /* Round functions. */
416 #define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) )
417 #define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) )
419 /* Process LEN bytes of BUFFER, accumulating context into CTX.
420 It is assumed that LEN % 64 == 0.
421 Most of this code comes from GnuPG's cipher/sha1.c. */
424 sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
426 const uint32_t *words = buffer;
427 size_t nwords = len / sizeof (uint32_t);
428 const uint32_t *endp = words + nwords;
430 uint32_t a = ctx->state[0];
431 uint32_t b = ctx->state[1];
432 uint32_t c = ctx->state[2];
433 uint32_t d = ctx->state[3];
434 uint32_t e = ctx->state[4];
435 uint32_t f = ctx->state[5];
436 uint32_t g = ctx->state[6];
437 uint32_t h = ctx->state[7];
439 /* First increment the byte count. FIPS PUB 180-2 specifies the possible
440 length of the file up to 2^64 bits. Here we only compute the
441 number of bytes. Do a double word increment. */
442 ctx->total[0] += len;
443 if (ctx->total[0] < len)
446 #define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
447 #define S0(x) (rol(x,25)^rol(x,14)^(x>>3))
448 #define S1(x) (rol(x,15)^rol(x,13)^(x>>10))
449 #define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10))
450 #define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7))
452 #define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \
453 + S0(x[(I-15)&0x0f]) + x[I&0x0f] \
456 #define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \
461 D += t1; H = t0 + t1; \
469 /* FIXME: see sha1.c for a better implementation. */
470 for (t = 0; t < 16; t++)
472 x[t] = SWAP (*words);
476 R( a, b, c, d, e, f, g, h, K( 0), x[ 0] );
477 R( h, a, b, c, d, e, f, g, K( 1), x[ 1] );
478 R( g, h, a, b, c, d, e, f, K( 2), x[ 2] );
479 R( f, g, h, a, b, c, d, e, K( 3), x[ 3] );
480 R( e, f, g, h, a, b, c, d, K( 4), x[ 4] );
481 R( d, e, f, g, h, a, b, c, K( 5), x[ 5] );
482 R( c, d, e, f, g, h, a, b, K( 6), x[ 6] );
483 R( b, c, d, e, f, g, h, a, K( 7), x[ 7] );
484 R( a, b, c, d, e, f, g, h, K( 8), x[ 8] );
485 R( h, a, b, c, d, e, f, g, K( 9), x[ 9] );
486 R( g, h, a, b, c, d, e, f, K(10), x[10] );
487 R( f, g, h, a, b, c, d, e, K(11), x[11] );
488 R( e, f, g, h, a, b, c, d, K(12), x[12] );
489 R( d, e, f, g, h, a, b, c, K(13), x[13] );
490 R( c, d, e, f, g, h, a, b, K(14), x[14] );
491 R( b, c, d, e, f, g, h, a, K(15), x[15] );
492 R( a, b, c, d, e, f, g, h, K(16), M(16) );
493 R( h, a, b, c, d, e, f, g, K(17), M(17) );
494 R( g, h, a, b, c, d, e, f, K(18), M(18) );
495 R( f, g, h, a, b, c, d, e, K(19), M(19) );
496 R( e, f, g, h, a, b, c, d, K(20), M(20) );
497 R( d, e, f, g, h, a, b, c, K(21), M(21) );
498 R( c, d, e, f, g, h, a, b, K(22), M(22) );
499 R( b, c, d, e, f, g, h, a, K(23), M(23) );
500 R( a, b, c, d, e, f, g, h, K(24), M(24) );
501 R( h, a, b, c, d, e, f, g, K(25), M(25) );
502 R( g, h, a, b, c, d, e, f, K(26), M(26) );
503 R( f, g, h, a, b, c, d, e, K(27), M(27) );
504 R( e, f, g, h, a, b, c, d, K(28), M(28) );
505 R( d, e, f, g, h, a, b, c, K(29), M(29) );
506 R( c, d, e, f, g, h, a, b, K(30), M(30) );
507 R( b, c, d, e, f, g, h, a, K(31), M(31) );
508 R( a, b, c, d, e, f, g, h, K(32), M(32) );
509 R( h, a, b, c, d, e, f, g, K(33), M(33) );
510 R( g, h, a, b, c, d, e, f, K(34), M(34) );
511 R( f, g, h, a, b, c, d, e, K(35), M(35) );
512 R( e, f, g, h, a, b, c, d, K(36), M(36) );
513 R( d, e, f, g, h, a, b, c, K(37), M(37) );
514 R( c, d, e, f, g, h, a, b, K(38), M(38) );
515 R( b, c, d, e, f, g, h, a, K(39), M(39) );
516 R( a, b, c, d, e, f, g, h, K(40), M(40) );
517 R( h, a, b, c, d, e, f, g, K(41), M(41) );
518 R( g, h, a, b, c, d, e, f, K(42), M(42) );
519 R( f, g, h, a, b, c, d, e, K(43), M(43) );
520 R( e, f, g, h, a, b, c, d, K(44), M(44) );
521 R( d, e, f, g, h, a, b, c, K(45), M(45) );
522 R( c, d, e, f, g, h, a, b, K(46), M(46) );
523 R( b, c, d, e, f, g, h, a, K(47), M(47) );
524 R( a, b, c, d, e, f, g, h, K(48), M(48) );
525 R( h, a, b, c, d, e, f, g, K(49), M(49) );
526 R( g, h, a, b, c, d, e, f, K(50), M(50) );
527 R( f, g, h, a, b, c, d, e, K(51), M(51) );
528 R( e, f, g, h, a, b, c, d, K(52), M(52) );
529 R( d, e, f, g, h, a, b, c, K(53), M(53) );
530 R( c, d, e, f, g, h, a, b, K(54), M(54) );
531 R( b, c, d, e, f, g, h, a, K(55), M(55) );
532 R( a, b, c, d, e, f, g, h, K(56), M(56) );
533 R( h, a, b, c, d, e, f, g, K(57), M(57) );
534 R( g, h, a, b, c, d, e, f, K(58), M(58) );
535 R( f, g, h, a, b, c, d, e, K(59), M(59) );
536 R( e, f, g, h, a, b, c, d, K(60), M(60) );
537 R( d, e, f, g, h, a, b, c, K(61), M(61) );
538 R( c, d, e, f, g, h, a, b, K(62), M(62) );
539 R( b, c, d, e, f, g, h, a, K(63), M(63) );
541 a = ctx->state[0] += a;
542 b = ctx->state[1] += b;
543 c = ctx->state[2] += c;
544 d = ctx->state[3] += d;
545 e = ctx->state[4] += e;
546 f = ctx->state[5] += f;
547 g = ctx->state[6] += g;
548 h = ctx->state[7] += h;