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Table for driving key data extraction.
[u/mdw/catacomb] / hash.h
1 /* -*-c-*-
2 *
3 * $Id: hash.h,v 1.2 1999/12/10 23:16:40 mdw Exp $
4 *
5 * Generic handling for message digest functions
6 *
7 * (c) 1998 Straylight/Edgeware
8 */
9
10 /*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of Catacomb.
13 *
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
30 /*----- Revision history --------------------------------------------------*
31 *
32 * $Log: hash.h,v $
33 * Revision 1.2 1999/12/10 23:16:40 mdw
34 * Split mode macros into interface and implementation.
35 *
36 * Revision 1.1 1999/09/03 08:41:12 mdw
37 * Initial import.
38 *
39 */
40
41 #ifndef CATACOMB_HASH_H
42 #define CATACOMB_HASH_H
43
44 #ifdef __cplusplus
45 extern "C" {
46 #endif
47
48 /*----- Header files ------------------------------------------------------*/
49
50 #include <string.h>
51
52 #include <mLib/bits.h>
53
54 /*----- Macros ------------------------------------------------------------*/
55
56 /* --- @HASH_BUFFER@ --- *
57 *
58 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
59 * @ictx@ = pointer to context block for the hash
60 * @ibuf@ = pointer to input data to hash
61 * @isz@ = size of buffer
62 *
63 * Use: Handles buffering of input data to a hash function. The
64 * hash's compression function is called when the buffer is
65 * full. Note that the compression function can be called on
66 * data which is at odd alignments; it is expected to cope
67 * gracefully with this (possibly by copying the data into its
68 * internal buffer before starting).
69 */
70
71 #define HASH_BUFFER(PRE, pre, ictx, ibuf, isz) do { \
72 pre##_ctx *_bctx = (ictx); \
73 size_t _bsz = (isz); \
74 const octet *_bbuf = (octet *)(ibuf); \
75 \
76 /* --- Add on the size done so far --- * \
77 * \
78 * Messy, because trapping overflow is difficult when you don't know \
79 * how many bits you've actually got. \
80 */ \
81 \
82 { \
83 uint32 _l = U32(_bsz), _h = (_bsz >> 16) >> 16; \
84 _bctx->nh += _h; \
85 _bctx->nl += _l; \
86 if (_bctx->nl < _l || _bctx->nl & ~MASK32) \
87 _bctx->nh++; \
88 } \
89 \
90 /* --- Handle very small contributions --- */ \
91 \
92 if (_bctx->off + _bsz < PRE##_BUFSZ) { \
93 memcpy(_bctx->buf + _bctx->off, _bbuf, _bsz); \
94 _bctx->off += _bsz; \
95 } else { \
96 \
97 /* --- Handle an initial partial buffer --- */ \
98 \
99 if (_bctx->off) { \
100 size_t s = PRE##_BUFSZ - _bctx->off; \
101 memcpy(_bctx->buf + _bctx->off, _bbuf, s); \
102 pre##_compress(_bctx, _bctx->buf); \
103 _bsz -= s; _bbuf += s; \
104 } \
105 \
106 /* --- Do whole buffers while we can --- */ \
107 \
108 while (_bsz >= PRE##_BUFSZ) { \
109 pre##_compress(_bctx, _bbuf); \
110 _bsz -= PRE##_BUFSZ; _bbuf += PRE##_BUFSZ; \
111 } \
112 \
113 /* --- And wrap up at the end --- */ \
114 \
115 if (_bsz) \
116 memcpy(_bctx->buf, _bbuf, _bsz); \
117 _bctx->off = _bsz; \
118 } \
119 } while (0)
120
121 /* --- @HASH_PAD@ --- *
122 *
123 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
124 * @ictx@ = pointer to context block for the hash
125 * @term@ = terminator character to write following the data
126 * @pad@ = pad character to fill with
127 * @diff@ = size of space to leave at the end of the last block
128 *
129 * Use: Does padding for message digest functions.
130 */
131
132 #define HASH_PAD(PRE, pre, ictx, term, pad, diff) do { \
133 pre##_ctx *_pctx = (ictx); \
134 \
135 _pctx->buf[_pctx->off] = term; \
136 _pctx->off++; \
137 if (_pctx->off > PRE##_BUFSZ - diff) { \
138 if (_pctx->off < PRE##_BUFSZ) \
139 memset(_pctx->buf + _pctx->off, pad, PRE##_BUFSZ - _pctx->off); \
140 pre##_compress(_pctx, _pctx->buf); \
141 memset(_pctx->buf, pad, PRE##_BUFSZ - diff); \
142 } else \
143 memset(_pctx->buf + _pctx->off, pad, \
144 PRE##_BUFSZ - _pctx->off - diff); \
145 } while (0)
146
147 /* --- @HASH_MD5STRENGTH@ --- *
148 *
149 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
150 * @ictx@ = pointer to context block for the hash
151 *
152 * Use: Does MD5-style MD strengthening. The data is terminated
153 * by a single set bit, padded with zero bits, and then a 64-
154 * bit length is written, little-end first.
155 */
156
157 #define HASH_MD5STRENGTH(PRE, pre, ictx) do { \
158 pre##_ctx *_mctx = (ictx); \
159 HASH_PAD(PRE, pre, _mctx, 0x80u, 0, 8); \
160 STORE32_L(_mctx->buf + PRE##_BUFSZ - 8, _mctx->nl << 3); \
161 STORE32_L(_mctx->buf + PRE##_BUFSZ - 4, \
162 (_mctx->nl >> 29) | (_mctx->nh << 3)); \
163 pre##_compress(_mctx, _mctx->buf); \
164 } while (0)
165
166 /* --- @HASH_TEST@ --- *
167 *
168 * Arguments: @PRE@, @pre@ = prefixes for hash-specfic definitions
169 *
170 * Use: Standard test rig for hash functions.
171 */
172
173 #ifdef TEST_RIG
174
175 #include <mLib/quis.h>
176 #include <mLib/testrig.h>
177
178 #define HASH_TEST(PRE, pre) \
179 \
180 static int verify(dstr *v) \
181 { \
182 pre##_ctx ctx; \
183 int ok = 1; \
184 int i; \
185 octet *p; \
186 int szs[] = { 1, 7, 192, -1, 0 }, *ip; \
187 size_t sz; \
188 dstr d; \
189 \
190 dstr_create(&d); \
191 dstr_ensure(&d, PRE##_HASHSZ); \
192 d.len = PRE##_HASHSZ; \
193 \
194 for (ip = szs; *ip; ip++) { \
195 i = *ip; \
196 sz = v[0].len; \
197 if (i == -1) \
198 i = sz; \
199 if (i > sz) \
200 continue; \
201 p = (octet *)v[0].buf; \
202 pre##_init(&ctx); \
203 while (sz) { \
204 if (i > sz) \
205 i = sz; \
206 pre##_hash(&ctx, p, i); \
207 p += i; \
208 sz -= i; \
209 } \
210 pre##_done(&ctx, d.buf); \
211 if (memcmp(d.buf, v[1].buf, PRE##_HASHSZ) != 0) { \
212 printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\texpected = ", \
213 *ip, v[0].buf); \
214 type_hex.dump(&v[1], stdout); \
215 fputs("\n\tcomputed = ", stdout); \
216 type_hex.dump(&d, stdout); \
217 putchar('\n'); \
218 ok = 0; \
219 } \
220 } \
221 \
222 dstr_destroy(&d); \
223 return (ok); \
224 } \
225 \
226 static test_chunk defs[] = { \
227 { #pre, verify, { &type_string, &type_hex, 0 } }, \
228 { 0, 0, { 0 } } \
229 }; \
230 \
231 int main(int argc, char *argv[]) \
232 { \
233 ego(argv[0]); \
234 test_run(argc, argv, defs, SRCDIR"/tests/" #pre); \
235 return (0); \
236 }
237
238 #else
239 # define HASH_TEST(PRE, pre)
240 #endif
241
242 /*----- That's all, folks -------------------------------------------------*/
243
244 #ifdef __cplusplus
245 }
246 #endif
247
248 #endif
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)