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authorSergey Poznyakoff <gray@gnu.org.ua>2012-09-19 11:28:28 +0300
committerSergey Poznyakoff <gray@gnu.org.ua>2012-09-19 18:30:01 +0300
commit1153970626892573e5966e135e8d81185f4ea53c (patch)
tree773fdf5a8d00ec2ef752c3a8fd5f32c79829cf23 /lib/sha1.c
downloadeclat-1153970626892573e5966e135e8d81185f4ea53c.tar.gz
eclat-1153970626892573e5966e135e8d81185f4ea53c.tar.bz2
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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 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#ifdef HAVE_CONFIG_H
27# include <config.h>
28#endif
29
30#include <sha1.h>
31
32#include <stddef.h>
33#include <string.h>
34
35#if USE_UNLOCKED_IO
36# include "unlocked-io.h"
37#endif
38
39#ifdef WORDS_BIGENDIAN
40# define SWAP(n) (n)
41#else
42# define SWAP(n) \
43 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
44#endif
45
46#define BLOCKSIZE 4096
47#if BLOCKSIZE % 64 != 0
48# error "invalid BLOCKSIZE"
49#endif
50
51/* This array contains the bytes used to pad the buffer to the next
52 64-byte boundary. (RFC 1321, 3.1: Step 1) */
53static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
54
55
56/* Take a pointer to a 160 bit block of data (five 32 bit ints) and
57 initialize it to the start constants of the SHA1 algorithm. This
58 must be called before using hash in the call to sha1_hash. */
59void
60sha1_init_ctx (struct sha1_ctx *ctx)
61{
62 ctx->A = 0x67452301;
63 ctx->B = 0xefcdab89;
64 ctx->C = 0x98badcfe;
65 ctx->D = 0x10325476;
66 ctx->E = 0xc3d2e1f0;
67
68 ctx->total[0] = ctx->total[1] = 0;
69 ctx->buflen = 0;
70}
71
72/* Put result from CTX in first 20 bytes following RESBUF. The result
73 must be in little endian byte order.
74
75 IMPORTANT: On some systems it is required that RESBUF is correctly
76 aligned for a 32-bit value. */
77void *
78sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
79{
80 ((uint32_t *) resbuf)[0] = SWAP (ctx->A);
81 ((uint32_t *) resbuf)[1] = SWAP (ctx->B);
82 ((uint32_t *) resbuf)[2] = SWAP (ctx->C);
83 ((uint32_t *) resbuf)[3] = SWAP (ctx->D);
84 ((uint32_t *) resbuf)[4] = SWAP (ctx->E);
85
86 return resbuf;
87}
88
89/* Process the remaining bytes in the internal buffer and the usual
90 prolog according to the standard and write the result to RESBUF.
91
92 IMPORTANT: On some systems it is required that RESBUF is correctly
93 aligned for a 32-bit value. */
94void *
95sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
96{
97 /* Take yet unprocessed bytes into account. */
98 uint32_t bytes = ctx->buflen;
99 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
100
101 /* Now count remaining bytes. */
102 ctx->total[0] += bytes;
103 if (ctx->total[0] < bytes)
104 ++ctx->total[1];
105
106 /* Put the 64-bit file length in *bits* at the end of the buffer. */
107 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
108 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
109
110 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
111
112 /* Process last bytes. */
113 sha1_process_block (ctx->buffer, size * 4, ctx);
114
115 return sha1_read_ctx (ctx, resbuf);
116}
117
118/* Compute SHA1 message digest for bytes read from STREAM. The
119 resulting message digest number will be written into the 16 bytes
120 beginning at RESBLOCK. */
121int
122sha1_stream (FILE *stream, void *resblock)
123{
124 struct sha1_ctx ctx;
125 char buffer[BLOCKSIZE + 72];
126 size_t sum;
127
128 /* Initialize the computation context. */
129 sha1_init_ctx (&ctx);
130
131 /* Iterate over full file contents. */
132 while (1)
133 {
134 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
135 computation function processes the whole buffer so that with the
136 next round of the loop another block can be read. */
137 size_t n;
138 sum = 0;
139
140 /* Read block. Take care for partial reads. */
141 while (1)
142 {
143 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
144
145 sum += n;
146
147 if (sum == BLOCKSIZE)
148 break;
149
150 if (n == 0)
151 {
152 /* Check for the error flag IFF N == 0, so that we don't
153 exit the loop after a partial read due to e.g., EAGAIN
154 or EWOULDBLOCK. */
155 if (ferror (stream))
156 return 1;
157 goto process_partial_block;
158 }
159
160 /* We've read at least one byte, so ignore errors. But always
161 check for EOF, since feof may be true even though N > 0.
162 Otherwise, we could end up calling fread after EOF. */
163 if (feof (stream))
164 goto process_partial_block;
165 }
166
167 /* Process buffer with BLOCKSIZE bytes. Note that
168 BLOCKSIZE % 64 == 0
169 */
170 sha1_process_block (buffer, BLOCKSIZE, &ctx);
171 }
172
173 process_partial_block:;
174
175 /* Process any remaining bytes. */
176 if (sum > 0)
177 sha1_process_bytes (buffer, sum, &ctx);
178
179 /* Construct result in desired memory. */
180 sha1_finish_ctx (&ctx, resblock);
181 return 0;
182}
183
184/* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The
185 result is always in little endian byte order, so that a byte-wise
186 output yields to the wanted ASCII representation of the message
187 digest. */
188void *
189sha1_buffer (const char *buffer, size_t len, void *resblock)
190{
191 struct sha1_ctx ctx;
192
193 /* Initialize the computation context. */
194 sha1_init_ctx (&ctx);
195
196 /* Process whole buffer but last len % 64 bytes. */
197 sha1_process_bytes (buffer, len, &ctx);
198
199 /* Put result in desired memory area. */
200 return sha1_finish_ctx (&ctx, resblock);
201}
202
203void
204sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
205{
206 /* When we already have some bits in our internal buffer concatenate
207 both inputs first. */
208 if (ctx->buflen != 0)
209 {
210 size_t left_over = ctx->buflen;
211 size_t add = 128 - left_over > len ? len : 128 - left_over;
212
213 memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
214 ctx->buflen += add;
215
216 if (ctx->buflen > 64)
217 {
218 sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
219
220 ctx->buflen &= 63;
221 /* The regions in the following copy operation cannot overlap. */
222 memcpy (ctx->buffer,
223 &((char *) ctx->buffer)[(left_over + add) & ~63],
224 ctx->buflen);
225 }
226
227 buffer = (const char *) buffer + add;
228 len -= add;
229 }
230
231 /* Process available complete blocks. */
232 if (len >= 64)
233 {
234#if !_STRING_ARCH_unaligned
235# define alignof(type) offsetof (struct { char c; type x; }, x)
236# define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0)
237 if (UNALIGNED_P (buffer))
238 while (len > 64)
239 {
240 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
241 buffer = (const char *) buffer + 64;
242 len -= 64;
243 }
244 else
245#endif
246 {
247 sha1_process_block (buffer, len & ~63, ctx);
248 buffer = (const char *) buffer + (len