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
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 /* Put result from CTX in first 32 bytes following RESBUF. The result
89 must be in little endian byte order.
91 IMPORTANT: On some systems it is required that RESBUF is correctly
92 aligned for a 32-bit value. */
94 sha256_read_ctx (const struct sha256_ctx
*ctx
, void *resbuf
)
98 for (i
= 0; i
< 8; i
++)
99 ((uint32_t *) resbuf
)[i
] = SWAP (ctx
->state
[i
]);
105 sha224_read_ctx (const struct sha256_ctx
*ctx
, void *resbuf
)
109 for (i
= 0; i
< 7; i
++)
110 ((uint32_t *) resbuf
)[i
] = SWAP (ctx
->state
[i
]);
115 /* Process the remaining bytes in the internal buffer and the usual
116 prolog according to the standard and write the result to RESBUF.
118 IMPORTANT: On some systems it is required that RESBUF is correctly
119 aligned for a 32-bit value. */
121 sha256_conclude_ctx (struct sha256_ctx
*ctx
)
123 /* Take yet unprocessed bytes into account. */
124 uint32_t bytes
= ctx
->buflen
;
125 size_t size
= (bytes
< 56) ? 64 / 4 : 64 * 2 / 4;
127 /* Now count remaining bytes. */
128 ctx
->total
[0] += bytes
;
129 if (ctx
->total
[0] < bytes
)
132 /* Put the 64-bit file length in *bits* at the end of the buffer. */
133 ctx
->buffer
[size
- 2] = SWAP ((ctx
->total
[1] << 3) | (ctx
->total
[0] >> 29));
134 ctx
->buffer
[size
- 1] = SWAP (ctx
->total
[0] << 3);
136 memcpy (&((char *) ctx
->buffer
)[bytes
], fillbuf
, (size
- 2) * 4 - bytes
);
138 /* Process last bytes. */
139 sha256_process_block (ctx
->buffer
, size
* 4, ctx
);
143 sha256_finish_ctx (struct sha256_ctx
*ctx
, void *resbuf
)
145 sha256_conclude_ctx (ctx
);
146 return sha256_read_ctx (ctx
, resbuf
);
150 sha224_finish_ctx (struct sha256_ctx
*ctx
, void *resbuf
)
152 sha256_conclude_ctx (ctx
);
153 return sha224_read_ctx (ctx
, resbuf
);
156 /* Compute SHA256 message digest for bytes read from STREAM. The
157 resulting message digest number will be written into the 32 bytes
158 beginning at RESBLOCK. */
160 sha256_stream (FILE *stream
, void *resblock
)
162 struct sha256_ctx ctx
;
163 char buffer
[BLOCKSIZE
+ 72];
166 /* Initialize the computation context. */
167 sha256_init_ctx (&ctx
);
169 /* Iterate over full file contents. */
172 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
173 computation function processes the whole buffer so that with the
174 next round of the loop another block can be read. */
178 /* Read block. Take care for partial reads. */
181 n
= fread (buffer
+ sum
, 1, BLOCKSIZE
- sum
, stream
);
185 if (sum
== BLOCKSIZE
)
190 /* Check for the error flag IFF N == 0, so that we don't
191 exit the loop after a partial read due to e.g., EAGAIN
195 goto process_partial_block
;
198 /* We've read at least one byte, so ignore errors. But always
199 check for EOF, since feof may be true even though N > 0.
200 Otherwise, we could end up calling fread after EOF. */
202 goto process_partial_block
;
205 /* Process buffer with BLOCKSIZE bytes. Note that
208 sha256_process_block (buffer
, BLOCKSIZE
, &ctx
);
211 process_partial_block
:;
213 /* Process any remaining bytes. */
215 sha256_process_bytes (buffer
, sum
, &ctx
);
217 /* Construct result in desired memory. */
218 sha256_finish_ctx (&ctx
, resblock
);
222 /* FIXME: Avoid code duplication */
224 sha224_stream (FILE *stream
, void *resblock
)
226 struct sha256_ctx ctx
;
227 char buffer
[BLOCKSIZE
+ 72];
230 /* Initialize the computation context. */
231 sha224_init_ctx (&ctx
);
233 /* Iterate over full file contents. */
236 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
237 computation function processes the whole buffer so that with the
238 next round of the loop another block can be read. */
242 /* Read block. Take care for partial reads. */
245 n
= fread (buffer
+ sum
, 1, BLOCKSIZE
- sum
, stream
);
249 if (sum
== BLOCKSIZE
)
254 /* Check for the error flag IFF N == 0, so that we don't
255 exit the loop after a partial read due to e.g., EAGAIN
259 goto process_partial_block
;
262 /* We've read at least one byte, so ignore errors. But always
263 check for EOF, since feof may be true even though N > 0.
264 Otherwise, we could end up calling fread after EOF. */
266 goto process_partial_block
;
269 /* Process buffer with BLOCKSIZE bytes. Note that
272 sha256_process_block (buffer
, BLOCKSIZE
, &ctx
);
275 process_partial_block
:;
277 /* Process any remaining bytes. */
279 sha256_process_bytes (buffer
, sum
, &ctx
);
281 /* Construct result in desired memory. */
282 sha224_finish_ctx (&ctx
, resblock
);
286 /* Compute SHA512 message digest for LEN bytes beginning at BUFFER. The
287 result is always in little endian byte order, so that a byte-wise
288 output yields to the wanted ASCII representation of the message
291 sha256_buffer (const char *buffer
, size_t len
, void *resblock
)
293 struct sha256_ctx ctx
;
295 /* Initialize the computation context. */
296 sha256_init_ctx (&ctx
);
298 /* Process whole buffer but last len % 64 bytes. */
299 sha256_process_bytes (buffer
, len
, &ctx
);
301 /* Put result in desired memory area. */
302 return sha256_finish_ctx (&ctx
, resblock
);
306 sha224_buffer (const char *buffer
, size_t len
, void *resblock
)
308 struct sha256_ctx ctx
;
310 /* Initialize the computation context. */
311 sha224_init_ctx (&ctx
);
313 /* Process whole buffer but last len % 64 bytes. */
314 sha256_process_bytes (buffer
, len
, &ctx
);
316 /* Put result in desired memory area. */
317 return sha224_finish_ctx (&ctx
, resblock
);
321 sha256_process_bytes (const void *buffer
, size_t len
, struct sha256_ctx
*ctx
)
323 /* When we already have some bits in our internal buffer concatenate
324 both inputs first. */
325 if (ctx
->buflen
!= 0)
327 size_t left_over
= ctx
->buflen
;
328 size_t add
= 128 - left_over
> len
? len
: 128 - left_over
;
330 memcpy (&((char *) ctx
->buffer
)[left_over
], buffer
, add
);
333 if (ctx
->buflen
> 64)
335 sha256_process_block (ctx
->buffer
, ctx
->buflen
& ~63, ctx
);
338 /* The regions in the following copy operation cannot overlap. */
340 &((char *) ctx
->buffer
)[(left_over
+ add
) & ~63],
344 buffer
= (const char *) buffer
+ add
;
348 /* Process available complete blocks. */
351 #if !_STRING_ARCH_unaligned
352 # define alignof(type) offsetof (struct { char c; type x; }, x)
353 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
354 if (UNALIGNED_P (buffer
))
357 sha256_process_block (memcpy (ctx
->buffer
, buffer
, 64), 64, ctx
);
358 buffer
= (const char *) buffer
+ 64;
364 sha256_process_block (buffer
, len
& ~63, ctx
);
365 buffer
= (const char *) buffer
+ (len
& ~63);
370 /* Move remaining bytes in internal buffer. */
373 size_t left_over
= ctx
->buflen
;
375 memcpy (&((char *) ctx
->buffer
)[left_over
], buffer
, len
);
379 sha256_process_block (ctx
->buffer
, 64, ctx
);
381 memcpy (ctx
->buffer
, &ctx
->buffer
[16], left_over
);
383 ctx
->buflen
= left_over
;
387 /* --- Code below is the primary difference between sha1.c and sha256.c --- */
389 /* SHA256 round constants */
390 #define K(I) sha256_round_constants[I]
391 static const uint32_t sha256_round_constants
[64] = {
392 0x428a2f98UL
, 0x71374491UL
, 0xb5c0fbcfUL
, 0xe9b5dba5UL
,
393 0x3956c25bUL
, 0x59f111f1UL
, 0x923f82a4UL
, 0xab1c5ed5UL
,
394 0xd807aa98UL
, 0x12835b01UL
, 0x243185beUL
, 0x550c7dc3UL
,
395 0x72be5d74UL
, 0x80deb1feUL
, 0x9bdc06a7UL
, 0xc19bf174UL
,
396 0xe49b69c1UL
, 0xefbe4786UL
, 0x0fc19dc6UL
, 0x240ca1ccUL
,
397 0x2de92c6fUL
, 0x4a7484aaUL
, 0x5cb0a9dcUL
, 0x76f988daUL
,
398 0x983e5152UL
, 0xa831c66dUL
, 0xb00327c8UL
, 0xbf597fc7UL
,
399 0xc6e00bf3UL
, 0xd5a79147UL
, 0x06ca6351UL
, 0x14292967UL
,
400 0x27b70a85UL
, 0x2e1b2138UL
, 0x4d2c6dfcUL
, 0x53380d13UL
,
401 0x650a7354UL
, 0x766a0abbUL
, 0x81c2c92eUL
, 0x92722c85UL
,
402 0xa2bfe8a1UL
, 0xa81a664bUL
, 0xc24b8b70UL
, 0xc76c51a3UL
,
403 0xd192e819UL
, 0xd6990624UL
, 0xf40e3585UL
, 0x106aa070UL
,
404 0x19a4c116UL
, 0x1e376c08UL
, 0x2748774cUL
, 0x34b0bcb5UL
,
405 0x391c0cb3UL
, 0x4ed8aa4aUL
, 0x5b9cca4fUL
, 0x682e6ff3UL
,
406 0x748f82eeUL
, 0x78a5636fUL
, 0x84c87814UL
, 0x8cc70208UL
,
407 0x90befffaUL
, 0xa4506cebUL
, 0xbef9a3f7UL
, 0xc67178f2UL
,
410 /* Round functions. */
411 #define F2(A,B,C) ( ( A & B ) | ( C & ( A | B ) ) )
412 #define F1(E,F,G) ( G ^ ( E & ( F ^ G ) ) )
414 /* Process LEN bytes of BUFFER, accumulating context into CTX.
415 It is assumed that LEN % 64 == 0.
416 Most of this code comes from GnuPG's cipher/sha1.c. */
419 sha256_process_block (const void *buffer
, size_t len
, struct sha256_ctx
*ctx
)
421 const uint32_t *words
= buffer
;
422 size_t nwords
= len
/ sizeof (uint32_t);
423 const uint32_t *endp
= words
+ nwords
;
425 uint32_t a
= ctx
->state
[0];
426 uint32_t b
= ctx
->state
[1];
427 uint32_t c
= ctx
->state
[2];
428 uint32_t d
= ctx
->state
[3];
429 uint32_t e
= ctx
->state
[4];
430 uint32_t f
= ctx
->state
[5];
431 uint32_t g
= ctx
->state
[6];
432 uint32_t h
= ctx
->state
[7];
434 /* First increment the byte count. FIPS PUB 180-2 specifies the possible
435 length of the file up to 2^64 bits. Here we only compute the
436 number of bytes. Do a double word increment. */
437 ctx
->total
[0] += len
;
438 if (ctx
->total
[0] < len
)
441 #define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
442 #define S0(x) (rol(x,25)^rol(x,14)^(x>>3))
443 #define S1(x) (rol(x,15)^rol(x,13)^(x>>10))
444 #define SS0(x) (rol(x,30)^rol(x,19)^rol(x,10))
445 #define SS1(x) (rol(x,26)^rol(x,21)^rol(x,7))
447 #define M(I) ( tm = S1(x[(I-2)&0x0f]) + x[(I-7)&0x0f] \
448 + S0(x[(I-15)&0x0f]) + x[I&0x0f] \
451 #define R(A,B,C,D,E,F,G,H,K,M) do { t0 = SS0(A) + F2(A,B,C); \
456 D += t1; H = t0 + t1; \
464 /* FIXME: see sha1.c for a better implementation. */
465 for (t
= 0; t
< 16; t
++)
467 x
[t
] = SWAP (*words
);
471 R( a
, b
, c
, d
, e
, f
, g
, h
, K( 0), x
[ 0] );
472 R( h
, a
, b
, c
, d
, e
, f
, g
, K( 1), x
[ 1] );
473 R( g
, h
, a
, b
, c
, d
, e
, f
, K( 2), x
[ 2] );
474 R( f
, g
, h
, a
, b
, c
, d
, e
, K( 3), x
[ 3] );
475 R( e
, f
, g
, h
, a
, b
, c
, d
, K( 4), x
[ 4] );
476 R( d
, e
, f
, g
, h
, a
, b
, c
, K( 5), x
[ 5] );
477 R( c
, d
, e
, f
, g
, h
, a
, b
, K( 6), x
[ 6] );
478 R( b
, c
, d
, e
, f
, g
, h
, a
, K( 7), x
[ 7] );
479 R( a
, b
, c
, d
, e
, f
, g
, h
, K( 8), x
[ 8] );
480 R( h
, a
, b
, c
, d
, e
, f
, g
, K( 9), x
[ 9] );
481 R( g
, h
, a
, b
, c
, d
, e
, f
, K(10), x
[10] );
482 R( f
, g
, h
, a
, b
, c
, d
, e
, K(11), x
[11] );
483 R( e
, f
, g
, h
, a
, b
, c
, d
, K(12), x
[12] );
484 R( d
, e
, f
, g
, h
, a
, b
, c
, K(13), x
[13] );
485 R( c
, d
, e
, f
, g
, h
, a
, b
, K(14), x
[14] );
486 R( b
, c
, d
, e
, f
, g
, h
, a
, K(15), x
[15] );
487 R( a
, b
, c
, d
, e
, f
, g
, h
, K(16), M(16) );
488 R( h
, a
, b
, c
, d
, e
, f
, g
, K(17), M(17) );
489 R( g
, h
, a
, b
, c
, d
, e
, f
, K(18), M(18) );
490 R( f
, g
, h
, a
, b
, c
, d
, e
, K(19), M(19) );
491 R( e
, f
, g
, h
, a
, b
, c
, d
, K(20), M(20) );
492 R( d
, e
, f
, g
, h
, a
, b
, c
, K(21), M(21) );
493 R( c
, d
, e
, f
, g
, h
, a
, b
, K(22), M(22) );
494 R( b
, c
, d
, e
, f
, g
, h
, a
, K(23), M(23) );
495 R( a
, b
, c
, d
, e
, f
, g
, h
, K(24), M(24) );
496 R( h
, a
, b
, c
, d
, e
, f
, g
, K(25), M(25) );
497 R( g
, h
, a
, b
, c
, d
, e
, f
, K(26), M(26) );
498 R( f
, g
, h
, a
, b
, c
, d
, e
, K(27), M(27) );
499 R( e
, f
, g
, h
, a
, b
, c
, d
, K(28), M(28) );
500 R( d
, e
, f
, g
, h
, a
, b
, c
, K(29), M(29) );
501 R( c
, d
, e
, f
, g
, h
, a
, b
, K(30), M(30) );
502 R( b
, c
, d
, e
, f
, g
, h
, a
, K(31), M(31) );
503 R( a
, b
, c
, d
, e
, f
, g
, h
, K(32), M(32) );
504 R( h
, a
, b
, c
, d
, e
, f
, g
, K(33), M(33) );
505 R( g
, h
, a
, b
, c
, d
, e
, f
, K(34), M(34) );
506 R( f
, g
, h
, a
, b
, c
, d
, e
, K(35), M(35) );
507 R( e
, f
, g
, h
, a
, b
, c
, d
, K(36), M(36) );
508 R( d
, e
, f
, g
, h
, a
, b
, c
, K(37), M(37) );
509 R( c
, d
, e
, f
, g
, h
, a
, b
, K(38), M(38) );
510 R( b
, c
, d
, e
, f
, g
, h
, a
, K(39), M(39) );
511 R( a
, b
, c
, d
, e
, f
, g
, h
, K(40), M(40) );
512 R( h
, a
, b
, c
, d
, e
, f
, g
, K(41), M(41) );
513 R( g
, h
, a
, b
, c
, d
, e
, f
, K(42), M(42) );
514 R( f
, g
, h
, a
, b
, c
, d
, e
, K(43), M(43) );
515 R( e
, f
, g
, h
, a
, b
, c
, d
, K(44), M(44) );
516 R( d
, e
, f
, g
, h
, a
, b
, c
, K(45), M(45) );
517 R( c
, d
, e
, f
, g
, h
, a
, b
, K(46), M(46) );
518 R( b
, c
, d
, e
, f
, g
, h
, a
, K(47), M(47) );
519 R( a
, b
, c
, d
, e
, f
, g
, h
, K(48), M(48) );
520 R( h
, a
, b
, c
, d
, e
, f
, g
, K(49), M(49) );
521 R( g
, h
, a
, b
, c
, d
, e
, f
, K(50), M(50) );
522 R( f
, g
, h
, a
, b
, c
, d
, e
, K(51), M(51) );
523 R( e
, f
, g
, h
, a
, b
, c
, d
, K(52), M(52) );
524 R( d
, e
, f
, g
, h
, a
, b
, c
, K(53), M(53) );
525 R( c
, d
, e
, f
, g
, h
, a
, b
, K(54), M(54) );
526 R( b
, c
, d
, e
, f
, g
, h
, a
, K(55), M(55) );
527 R( a
, b
, c
, d
, e
, f
, g
, h
, K(56), M(56) );
528 R( h
, a
, b
, c
, d
, e
, f
, g
, K(57), M(57) );
529 R( g
, h
, a
, b
, c
, d
, e
, f
, K(58), M(58) );
530 R( f
, g
, h
, a
, b
, c
, d
, e
, K(59), M(59) );
531 R( e
, f
, g
, h
, a
, b
, c
, d
, K(60), M(60) );
532 R( d
, e
, f
, g
, h
, a
, b
, c
, K(61), M(61) );
533 R( c
, d
, e
, f
, g
, h
, a
, b
, K(62), M(62) );
534 R( b
, c
, d
, e
, f
, g
, h
, a
, K(63), M(63) );
536 a
= ctx
->state
[0] += a
;
537 b
= ctx
->state
[1] += b
;
538 c
= ctx
->state
[2] += c
;
539 d
= ctx
->state
[3] += d
;
540 e
= ctx
->state
[4] += e
;
541 f
= ctx
->state
[5] += f
;
542 g
= ctx
->state
[6] += g
;
543 h
= ctx
->state
[7] += h
;