Annotation of src/external/gpl3/binutils/dist/libiberty/sha1.c, Revision 1.1.1.2
1.1 skrll 1: /* sha1.c - Functions to compute SHA1 message digest of files or
2: memory blocks according to the NIST specification FIPS-180-1.
3:
4: Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2008 Free Software
5: Foundation, Inc.
6:
7: This program is free software; you can redistribute it and/or modify it
8: under the terms of the GNU General Public License as published by the
9: Free Software Foundation; either version 2, or (at your option) any
10: later version.
11:
12: This program is distributed in the hope that it will be useful,
13: but WITHOUT ANY WARRANTY; without even the implied warranty of
14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: GNU General Public License for more details.
16:
17: You should have received a copy of the GNU General Public License
18: along with this program; if not, write to the Free Software Foundation,
19: Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20:
21: /* Written by Scott G. Miller
22: Credits:
23: Robert Klep <robert@ilse.nl> -- Expansion function fix
24: */
25:
26: #include <config.h>
27:
28: #include "sha1.h"
29:
30: #include <stddef.h>
31: #include <string.h>
32:
33: #if USE_UNLOCKED_IO
34: # include "unlocked-io.h"
35: #endif
36:
37: #ifdef WORDS_BIGENDIAN
38: # define SWAP(n) (n)
39: #else
40: # define SWAP(n) \
41: (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
42: #endif
43:
44: #define BLOCKSIZE 4096
45: #if BLOCKSIZE % 64 != 0
46: # error "invalid BLOCKSIZE"
47: #endif
48:
49: /* This array contains the bytes used to pad the buffer to the next
50: 64-byte boundary. (RFC 1321, 3.1: Step 1) */
51: static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
52:
53:
54: /* Take a pointer to a 160 bit block of data (five 32 bit ints) and
55: initialize it to the start constants of the SHA1 algorithm. This
56: must be called before using hash in the call to sha1_hash. */
57: void
58: sha1_init_ctx (struct sha1_ctx *ctx)
59: {
60: ctx->A = 0x67452301;
61: ctx->B = 0xefcdab89;
62: ctx->C = 0x98badcfe;
63: ctx->D = 0x10325476;
64: ctx->E = 0xc3d2e1f0;
65:
66: ctx->total[0] = ctx->total[1] = 0;
67: ctx->buflen = 0;
68: }
69:
70: /* Put result from CTX in first 20 bytes following RESBUF. The result
71: must be in little endian byte order.
72:
73: IMPORTANT: On some systems it is required that RESBUF is correctly
74: aligned for a 32-bit value. */
75: void *
76: sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
77: {
78: ((sha1_uint32 *) resbuf)[0] = SWAP (ctx->A);
79: ((sha1_uint32 *) resbuf)[1] = SWAP (ctx->B);
80: ((sha1_uint32 *) resbuf)[2] = SWAP (ctx->C);
81: ((sha1_uint32 *) resbuf)[3] = SWAP (ctx->D);
82: ((sha1_uint32 *) resbuf)[4] = SWAP (ctx->E);
83:
84: return resbuf;
85: }
86:
87: /* Process the remaining bytes in the internal buffer and the usual
88: prolog according to the standard and write the result to RESBUF.
89:
90: IMPORTANT: On some systems it is required that RESBUF is correctly
91: aligned for a 32-bit value. */
92: void *
93: sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
94: {
95: /* Take yet unprocessed bytes into account. */
96: sha1_uint32 bytes = ctx->buflen;
97: size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
98:
99: /* Now count remaining bytes. */
100: ctx->total[0] += bytes;
101: if (ctx->total[0] < bytes)
102: ++ctx->total[1];
103:
104: /* Put the 64-bit file length in *bits* at the end of the buffer. */
105: ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
106: ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
107:
108: memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
109:
110: /* Process last bytes. */
111: sha1_process_block (ctx->buffer, size * 4, ctx);
112:
113: return sha1_read_ctx (ctx, resbuf);
114: }
115:
116: /* Compute SHA1 message digest for bytes read from STREAM. The
117: resulting message digest number will be written into the 16 bytes
118: beginning at RESBLOCK. */
119: int
120: sha1_stream (FILE *stream, void *resblock)
121: {
122: struct sha1_ctx ctx;
123: char buffer[BLOCKSIZE + 72];
124: size_t sum;
125:
126: /* Initialize the computation context. */
127: sha1_init_ctx (&ctx);
128:
129: /* Iterate over full file contents. */
130: while (1)
131: {
132: /* We read the file in blocks of BLOCKSIZE bytes. One call of the
133: computation function processes the whole buffer so that with the
134: next round of the loop another block can be read. */
135: size_t n;
136: sum = 0;
137:
138: /* Read block. Take care for partial reads. */
139: while (1)
140: {
141: n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
142:
143: sum += n;
144:
145: if (sum == BLOCKSIZE)
146: break;
147:
148: if (n == 0)
149: {
150: /* Check for the error flag IFF N == 0, so that we don't
151: exit the loop after a partial read due to e.g., EAGAIN
152: or EWOULDBLOCK. */
153: if (ferror (stream))
154: return 1;
155: goto process_partial_block;
156: }
157:
158: /* We've read at least one byte, so ignore errors. But always
159: check for EOF, since feof may be true even though N > 0.
160: Otherwise, we could end up calling fread after EOF. */
161: if (feof (stream))
162: goto process_partial_block;
163: }
164:
165: /* Process buffer with BLOCKSIZE bytes. Note that
166: BLOCKSIZE % 64 == 0
167: */
168: sha1_process_block (buffer, BLOCKSIZE, &ctx);
169: }
170:
171: process_partial_block:;
172:
173: /* Process any remaining bytes. */
174: if (sum > 0)
175: sha1_process_bytes (buffer, sum, &ctx);
176:
177: /* Construct result in desired memory. */
178: sha1_finish_ctx (&ctx, resblock);
179: return 0;
180: }
181:
182: /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The
183: result is always in little endian byte order, so that a byte-wise
184: output yields to the wanted ASCII representation of the message
185: digest. */
186: void *
187: sha1_buffer (const char *buffer, size_t len, void *resblock)
188: {
189: struct sha1_ctx ctx;
190:
191: /* Initialize the computation context. */
192: sha1_init_ctx (&ctx);
193:
194: /* Process whole buffer but last len % 64 bytes. */
195: sha1_process_bytes (buffer, len, &ctx);
196:
197: /* Put result in desired memory area. */
198: return sha1_finish_ctx (&ctx, resblock);
199: }
200:
201: void
202: sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
203: {
204: /* When we already have some bits in our internal buffer concatenate
205: both inputs first. */
206: if (ctx->buflen != 0)
207: {
208: size_t left_over = ctx->buflen;
209: size_t add = 128 - left_over > len ? len : 128 - left_over;
210:
211: memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
212: ctx->buflen += add;
213:
214: if (ctx->buflen > 64)
215: {
216: sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
217:
218: ctx->buflen &= 63;
219: /* The regions in the following copy operation cannot overlap. */
220: memcpy (ctx->buffer,
221: &((char *) ctx->buffer)[(left_over + add) & ~63],
222: ctx->buflen);
223: }
224:
225: buffer = (const char *) buffer + add;
226: len -= add;
227: }
228:
229: /* Process available complete blocks. */
230: if (len >= 64)
231: {
232: #if !_STRING_ARCH_unaligned
233: # define alignof(type) offsetof (struct { char c; type x; }, x)
234: # define UNALIGNED_P(p) (((size_t) p) % alignof (sha1_uint32) != 0)
235: if (UNALIGNED_P (buffer))
236: while (len > 64)
237: {
238: sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
239: buffer = (const char *) buffer + 64;
240: len -= 64;
241: }
242: else
243: #endif
244: {
245: sha1_process_block (buffer, len & ~63, ctx);
246: buffer = (const char *) buffer + (len & ~63);
247: len &= 63;
248: }
249: }
250:
251: /* Move remaining bytes in internal buffer. */
252: if (len > 0)
253: {
254: size_t left_over = ctx->buflen;
255:
256: memcpy (&((char *) ctx->buffer)[left_over], buffer, len);
257: left_over += len;
258: if (left_over >= 64)
259: {
260: sha1_process_block (ctx->buffer, 64, ctx);
261: left_over -= 64;
262: memcpy (ctx->buffer, &ctx->buffer[16], left_over);
263: }
264: ctx->buflen = left_over;
265: }
266: }
267:
268: /* --- Code below is the primary difference between md5.c and sha1.c --- */
269:
270: /* SHA1 round constants */
271: #define K1 0x5a827999
272: #define K2 0x6ed9eba1
273: #define K3 0x8f1bbcdc
274: #define K4 0xca62c1d6
275:
276: /* Round functions. Note that F2 is the same as F4. */
277: #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
278: #define F2(B,C,D) (B ^ C ^ D)
279: #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
280: #define F4(B,C,D) (B ^ C ^ D)
281:
282: /* Process LEN bytes of BUFFER, accumulating context into CTX.
283: It is assumed that LEN % 64 == 0.
284: Most of this code comes from GnuPG's cipher/sha1.c. */
285:
286: void
287: sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
288: {
289: const sha1_uint32 *words = (const sha1_uint32*) buffer;
290: size_t nwords = len / sizeof (sha1_uint32);
291: const sha1_uint32 *endp = words + nwords;
292: sha1_uint32 x[16];
293: sha1_uint32 a = ctx->A;
294: sha1_uint32 b = ctx->B;
295: sha1_uint32 c = ctx->C;
296: sha1_uint32 d = ctx->D;
297: sha1_uint32 e = ctx->E;
298:
299: /* First increment the byte count. RFC 1321 specifies the possible
300: length of the file up to 2^64 bits. Here we only compute the
301: number of bytes. Do a double word increment. */
302: ctx->total[0] += len;
1.1.1.2 ! christos 303: ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len);
1.1 skrll 304:
305: #define rol(x, n) (((x) << (n)) | ((sha1_uint32) (x) >> (32 - (n))))
306:
307: #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \
308: ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
309: , (x[I&0x0f] = rol(tm, 1)) )
310:
311: #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \
312: + F( B, C, D ) \
313: + K \
314: + M; \
315: B = rol( B, 30 ); \
316: } while(0)
317:
318: while (words < endp)
319: {
320: sha1_uint32 tm;
321: int t;
322: for (t = 0; t < 16; t++)
323: {
324: x[t] = SWAP (*words);
325: words++;
326: }
327:
328: R( a, b, c, d, e, F1, K1, x[ 0] );
329: R( e, a, b, c, d, F1, K1, x[ 1] );
330: R( d, e, a, b, c, F1, K1, x[ 2] );
331: R( c, d, e, a, b, F1, K1, x[ 3] );
332: R( b, c, d, e, a, F1, K1, x[ 4] );
333: R( a, b, c, d, e, F1, K1, x[ 5] );
334: R( e, a, b, c, d, F1, K1, x[ 6] );
335: R( d, e, a, b, c, F1, K1, x[ 7] );
336: R( c, d, e, a, b, F1, K1, x[ 8] );
337: R( b, c, d, e, a, F1, K1, x[ 9] );
338: R( a, b, c, d, e, F1, K1, x[10] );
339: R( e, a, b, c, d, F1, K1, x[11] );
340: R( d, e, a, b, c, F1, K1, x[12] );
341: R( c, d, e, a, b, F1, K1, x[13] );
342: R( b, c, d, e, a, F1, K1, x[14] );
343: R( a, b, c, d, e, F1, K1, x[15] );
344: R( e, a, b, c, d, F1, K1, M(16) );
345: R( d, e, a, b, c, F1, K1, M(17) );
346: R( c, d, e, a, b, F1, K1, M(18) );
347: R( b, c, d, e, a, F1, K1, M(19) );
348: R( a, b, c, d, e, F2, K2, M(20) );
349: R( e, a, b, c, d, F2, K2, M(21) );
350: R( d, e, a, b, c, F2, K2, M(22) );
351: R( c, d, e, a, b, F2, K2, M(23) );
352: R( b, c, d, e, a, F2, K2, M(24) );
353: R( a, b, c, d, e, F2, K2, M(25) );
354: R( e, a, b, c, d, F2, K2, M(26) );
355: R( d, e, a, b, c, F2, K2, M(27) );
356: R( c, d, e, a, b, F2, K2, M(28) );
357: R( b, c, d, e, a, F2, K2, M(29) );
358: R( a, b, c, d, e, F2, K2, M(30) );
359: R( e, a, b, c, d, F2, K2, M(31) );
360: R( d, e, a, b, c, F2, K2, M(32) );
361: R( c, d, e, a, b, F2, K2, M(33) );
362: R( b, c, d, e, a, F2, K2, M(34) );
363: R( a, b, c, d, e, F2, K2, M(35) );
364: R( e, a, b, c, d, F2, K2, M(36) );
365: R( d, e, a, b, c, F2, K2, M(37) );
366: R( c, d, e, a, b, F2, K2, M(38) );
367: R( b, c, d, e, a, F2, K2, M(39) );
368: R( a, b, c, d, e, F3, K3, M(40) );
369: R( e, a, b, c, d, F3, K3, M(41) );
370: R( d, e, a, b, c, F3, K3, M(42) );
371: R( c, d, e, a, b, F3, K3, M(43) );
372: R( b, c, d, e, a, F3, K3, M(44) );
373: R( a, b, c, d, e, F3, K3, M(45) );
374: R( e, a, b, c, d, F3, K3, M(46) );
375: R( d, e, a, b, c, F3, K3, M(47) );
376: R( c, d, e, a, b, F3, K3, M(48) );
377: R( b, c, d, e, a, F3, K3, M(49) );
378: R( a, b, c, d, e, F3, K3, M(50) );
379: R( e, a, b, c, d, F3, K3, M(51) );
380: R( d, e, a, b, c, F3, K3, M(52) );
381: R( c, d, e, a, b, F3, K3, M(53) );
382: R( b, c, d, e, a, F3, K3, M(54) );
383: R( a, b, c, d, e, F3, K3, M(55) );
384: R( e, a, b, c, d, F3, K3, M(56) );
385: R( d, e, a, b, c, F3, K3, M(57) );
386: R( c, d, e, a, b, F3, K3, M(58) );
387: R( b, c, d, e, a, F3, K3, M(59) );
388: R( a, b, c, d, e, F4, K4, M(60) );
389: R( e, a, b, c, d, F4, K4, M(61) );
390: R( d, e, a, b, c, F4, K4, M(62) );
391: R( c, d, e, a, b, F4, K4, M(63) );
392: R( b, c, d, e, a, F4, K4, M(64) );
393: R( a, b, c, d, e, F4, K4, M(65) );
394: R( e, a, b, c, d, F4, K4, M(66) );
395: R( d, e, a, b, c, F4, K4, M(67) );
396: R( c, d, e, a, b, F4, K4, M(68) );
397: R( b, c, d, e, a, F4, K4, M(69) );
398: R( a, b, c, d, e, F4, K4, M(70) );
399: R( e, a, b, c, d, F4, K4, M(71) );
400: R( d, e, a, b, c, F4, K4, M(72) );
401: R( c, d, e, a, b, F4, K4, M(73) );
402: R( b, c, d, e, a, F4, K4, M(74) );
403: R( a, b, c, d, e, F4, K4, M(75) );
404: R( e, a, b, c, d, F4, K4, M(76) );
405: R( d, e, a, b, c, F4, K4, M(77) );
406: R( c, d, e, a, b, F4, K4, M(78) );
407: R( b, c, d, e, a, F4, K4, M(79) );
408:
409: a = ctx->A += a;
410: b = ctx->B += b;
411: c = ctx->C += c;
412: d = ctx->D += d;
413: e = ctx->E += e;
414: }
415: }
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