1 /* sha.c - Functions to compute the SHA1 hash (message-digest) of files
2 or blocks of memory. Complies to the NIST specification FIPS-180-1.
4 Copyright (C) 2000, 2001, 2003 Scott G. Miller
7 Robert Klep <robert@ilse.nl> -- Expansion function fix
14 #include <sys/types.h>
16 #if STDC_HEADERS || defined _LIBC
21 # define memcpy(d, s, n) bcopy ((s), (d), (n))
27 #include "unlocked-io.h"
30 Not-swap is a macro that does an endian swap on architectures that are
31 big-endian, as SHA needs some data in a little-endian format
34 #ifdef WORDS_BIGENDIAN
35 # define NOTSWAP(n) (n)
37 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
40 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
44 #define BLOCKSIZE 4096
45 /* Ensure that BLOCKSIZE is a multiple of 64. */
46 #if BLOCKSIZE % 64 != 0
47 /* FIXME-someday (soon?): use #error instead of this kludge. */
51 /* This array contains the bytes used to pad the buffer to the next
52 64-byte boundary. (RFC 1321, 3.1: Step 1) */
53 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
57 Takes a pointer to a 160 bit block of data (five 32 bit ints) and
58 intializes it to the start constants of the SHA1 algorithm. This
59 must be called before using hash in the call to sha_hash
62 sha_init_ctx (struct sha_ctx *ctx)
70 ctx->total[0] = ctx->total[1] = 0;
74 /* Put result from CTX in first 20 bytes following RESBUF. The result
75 must be in little endian byte order.
77 IMPORTANT: On some systems it is required that RESBUF is correctly
78 aligned for a 32 bits value. */
80 sha_read_ctx (const struct sha_ctx *ctx, void *resbuf)
82 ((md5_uint32 *) resbuf)[0] = NOTSWAP (ctx->A);
83 ((md5_uint32 *) resbuf)[1] = NOTSWAP (ctx->B);
84 ((md5_uint32 *) resbuf)[2] = NOTSWAP (ctx->C);
85 ((md5_uint32 *) resbuf)[3] = NOTSWAP (ctx->D);
86 ((md5_uint32 *) resbuf)[4] = NOTSWAP (ctx->E);
91 /* Process the remaining bytes in the internal buffer and the usual
92 prolog according to the standard and write the result to RESBUF.
94 IMPORTANT: On some systems it is required that RESBUF is correctly
95 aligned for a 32 bits value. */
97 sha_finish_ctx (struct sha_ctx *ctx, void *resbuf)
99 /* Take yet unprocessed bytes into account. */
100 md5_uint32 bytes = ctx->buflen;
103 /* Now count remaining bytes. */
104 ctx->total[0] += bytes;
105 if (ctx->total[0] < bytes)
108 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
109 memcpy (&ctx->buffer[bytes], fillbuf, pad);
111 /* Put the 64-bit file length in *bits* at the end of the buffer. */
112 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = NOTSWAP (ctx->total[0] << 3);
113 *(md5_uint32 *) &ctx->buffer[bytes + pad] = NOTSWAP ((ctx->total[1] << 3) |
114 (ctx->total[0] >> 29));
116 /* Process last bytes. */
117 sha_process_block (ctx->buffer, bytes + pad + 8, ctx);
119 return sha_read_ctx (ctx, resbuf);
122 /* Compute SHA1 message digest for bytes read from STREAM. The
123 resulting message digest number will be written into the 16 bytes
124 beginning at RESBLOCK. */
126 sha_stream (FILE *stream, void *resblock)
129 char buffer[BLOCKSIZE + 72];
132 /* Initialize the computation context. */
135 /* Iterate over full file contents. */
138 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
139 computation function processes the whole buffer so that with the
140 next round of the loop another block can be read. */
144 /* Read block. Take care for partial reads. */
147 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
151 if (sum == BLOCKSIZE)
156 /* Check for the error flag IFF N == 0, so that we don't
157 exit the loop after a partial read due to e.g., EAGAIN
161 goto process_partial_block;
164 /* We've read at least one byte, so ignore errors. But always
165 check for EOF, since feof may be true even though N > 0.
166 Otherwise, we could end up calling fread after EOF. */
168 goto process_partial_block;
171 /* Process buffer with BLOCKSIZE bytes. Note that
174 sha_process_block (buffer, BLOCKSIZE, &ctx);
177 process_partial_block:;
179 /* Process any remaining bytes. */
181 sha_process_bytes (buffer, sum, &ctx);
183 /* Construct result in desired memory. */
184 sha_finish_ctx (&ctx, resblock);
188 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
189 result is always in little endian byte order, so that a byte-wise
190 output yields to the wanted ASCII representation of the message
193 sha_buffer (const char *buffer, size_t len, void *resblock)
197 /* Initialize the computation context. */
200 /* Process whole buffer but last len % 64 bytes. */
201 sha_process_bytes (buffer, len, &ctx);
203 /* Put result in desired memory area. */
204 return sha_finish_ctx (&ctx, resblock);
208 sha_process_bytes (const void *buffer, size_t len, struct sha_ctx *ctx)
210 /* When we already have some bits in our internal buffer concatenate
211 both inputs first. */
212 if (ctx->buflen != 0)
214 size_t left_over = ctx->buflen;
215 size_t add = 128 - left_over > len ? len : 128 - left_over;
217 memcpy (&ctx->buffer[left_over], buffer, add);
220 if (ctx->buflen > 64)
222 sha_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
225 /* The regions in the following copy operation cannot overlap. */
226 memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
230 buffer = (const char *) buffer + add;
234 /* Process available complete blocks. */
237 #if !_STRING_ARCH_unaligned
238 /* To check alignment gcc has an appropriate operator. Other
241 # define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
243 # define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
245 if (UNALIGNED_P (buffer))
248 sha_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
249 buffer = (const char *) buffer + 64;
255 sha_process_block (buffer, len & ~63, ctx);
256 buffer = (const char *) buffer + (len & ~63);
261 /* Move remaining bytes in internal buffer. */
264 size_t left_over = ctx->buflen;
266 memcpy (&ctx->buffer[left_over], buffer, len);
270 sha_process_block (ctx->buffer, 64, ctx);
272 memcpy (ctx->buffer, &ctx->buffer[64], left_over);
274 ctx->buflen = left_over;
278 /* --- Code below is the primary difference between md5.c and sha.c --- */
280 /* SHA1 round constants */
281 #define K1 0x5a827999L
282 #define K2 0x6ed9eba1L
283 #define K3 0x8f1bbcdcL
284 #define K4 0xca62c1d6L
286 /* Round functions. Note that F2 is the same as F4. */
287 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
288 #define F2(B,C,D) (B ^ C ^ D)
289 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
290 #define F4(B,C,D) (B ^ C ^ D)
292 /* Process LEN bytes of BUFFER, accumulating context into CTX.
293 It is assumed that LEN % 64 == 0.
294 Most of this code comes from GnuPG's cipher/sha1.c. */
297 sha_process_block (const void *buffer, size_t len, struct sha_ctx *ctx)
299 const md5_uint32 *words = buffer;
300 size_t nwords = len / sizeof (md5_uint32);
301 const md5_uint32 *endp = words + nwords;
303 md5_uint32 a = ctx->A;
304 md5_uint32 b = ctx->B;
305 md5_uint32 c = ctx->C;
306 md5_uint32 d = ctx->D;
307 md5_uint32 e = ctx->E;
309 /* First increment the byte count. RFC 1321 specifies the possible
310 length of the file up to 2^64 bits. Here we only compute the
311 number of bytes. Do a double word increment. */
312 ctx->total[0] += len;
313 if (ctx->total[0] < len)
316 #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \
317 ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
318 , (x[I&0x0f] = rol(tm, 1)) )
320 #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \
331 /* FIXME: see sha1.c for a better implementation. */
332 for (t = 0; t < 16; t++)
334 x[t] = NOTSWAP (*words);
338 R( a, b, c, d, e, F1, K1, x[ 0] );
339 R( e, a, b, c, d, F1, K1, x[ 1] );
340 R( d, e, a, b, c, F1, K1, x[ 2] );
341 R( c, d, e, a, b, F1, K1, x[ 3] );
342 R( b, c, d, e, a, F1, K1, x[ 4] );
343 R( a, b, c, d, e, F1, K1, x[ 5] );
344 R( e, a, b, c, d, F1, K1, x[ 6] );
345 R( d, e, a, b, c, F1, K1, x[ 7] );
346 R( c, d, e, a, b, F1, K1, x[ 8] );
347 R( b, c, d, e, a, F1, K1, x[ 9] );
348 R( a, b, c, d, e, F1, K1, x[10] );
349 R( e, a, b, c, d, F1, K1, x[11] );
350 R( d, e, a, b, c, F1, K1, x[12] );
351 R( c, d, e, a, b, F1, K1, x[13] );
352 R( b, c, d, e, a, F1, K1, x[14] );
353 R( a, b, c, d, e, F1, K1, x[15] );
354 R( e, a, b, c, d, F1, K1, M(16) );
355 R( d, e, a, b, c, F1, K1, M(17) );
356 R( c, d, e, a, b, F1, K1, M(18) );
357 R( b, c, d, e, a, F1, K1, M(19) );
358 R( a, b, c, d, e, F2, K2, M(20) );
359 R( e, a, b, c, d, F2, K2, M(21) );
360 R( d, e, a, b, c, F2, K2, M(22) );
361 R( c, d, e, a, b, F2, K2, M(23) );
362 R( b, c, d, e, a, F2, K2, M(24) );
363 R( a, b, c, d, e, F2, K2, M(25) );
364 R( e, a, b, c, d, F2, K2, M(26) );
365 R( d, e, a, b, c, F2, K2, M(27) );
366 R( c, d, e, a, b, F2, K2, M(28) );
367 R( b, c, d, e, a, F2, K2, M(29) );
368 R( a, b, c, d, e, F2, K2, M(30) );
369 R( e, a, b, c, d, F2, K2, M(31) );
370 R( d, e, a, b, c, F2, K2, M(32) );
371 R( c, d, e, a, b, F2, K2, M(33) );
372 R( b, c, d, e, a, F2, K2, M(34) );
373 R( a, b, c, d, e, F2, K2, M(35) );
374 R( e, a, b, c, d, F2, K2, M(36) );
375 R( d, e, a, b, c, F2, K2, M(37) );
376 R( c, d, e, a, b, F2, K2, M(38) );
377 R( b, c, d, e, a, F2, K2, M(39) );
378 R( a, b, c, d, e, F3, K3, M(40) );
379 R( e, a, b, c, d, F3, K3, M(41) );
380 R( d, e, a, b, c, F3, K3, M(42) );
381 R( c, d, e, a, b, F3, K3, M(43) );
382 R( b, c, d, e, a, F3, K3, M(44) );
383 R( a, b, c, d, e, F3, K3, M(45) );
384 R( e, a, b, c, d, F3, K3, M(46) );
385 R( d, e, a, b, c, F3, K3, M(47) );
386 R( c, d, e, a, b, F3, K3, M(48) );
387 R( b, c, d, e, a, F3, K3, M(49) );
388 R( a, b, c, d, e, F3, K3, M(50) );
389 R( e, a, b, c, d, F3, K3, M(51) );
390 R( d, e, a, b, c, F3, K3, M(52) );
391 R( c, d, e, a, b, F3, K3, M(53) );
392 R( b, c, d, e, a, F3, K3, M(54) );
393 R( a, b, c, d, e, F3, K3, M(55) );
394 R( e, a, b, c, d, F3, K3, M(56) );
395 R( d, e, a, b, c, F3, K3, M(57) );
396 R( c, d, e, a, b, F3, K3, M(58) );
397 R( b, c, d, e, a, F3, K3, M(59) );
398 R( a, b, c, d, e, F4, K4, M(60) );
399 R( e, a, b, c, d, F4, K4, M(61) );
400 R( d, e, a, b, c, F4, K4, M(62) );
401 R( c, d, e, a, b, F4, K4, M(63) );
402 R( b, c, d, e, a, F4, K4, M(64) );
403 R( a, b, c, d, e, F4, K4, M(65) );
404 R( e, a, b, c, d, F4, K4, M(66) );
405 R( d, e, a, b, c, F4, K4, M(67) );
406 R( c, d, e, a, b, F4, K4, M(68) );
407 R( b, c, d, e, a, F4, K4, M(69) );
408 R( a, b, c, d, e, F4, K4, M(70) );
409 R( e, a, b, c, d, F4, K4, M(71) );
410 R( d, e, a, b, c, F4, K4, M(72) );
411 R( c, d, e, a, b, F4, K4, M(73) );
412 R( b, c, d, e, a, F4, K4, M(74) );
413 R( a, b, c, d, e, F4, K4, M(75) );
414 R( e, a, b, c, d, F4, K4, M(76) );
415 R( d, e, a, b, c, F4, K4, M(77) );
416 R( c, d, e, a, b, F4, K4, M(78) );
417 R( b, c, d, e, a, F4, K4, M(79) );