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[u/mdw/catacomb] / symm / hash.h
1 /* -*-c-*-
2 *
3 * Generic handling for message digest functions
4 *
5 * (c) 1998 Straylight/Edgeware
6 */
7
8 /*----- Licensing notice --------------------------------------------------*
9 *
10 * This file is part of Catacomb.
11 *
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
21 *
22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
25 * MA 02111-1307, USA.
26 */
27
28 #ifndef CATACOMB_HASH_H
29 #define CATACOMB_HASH_H
30
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34
35 /*----- Header files ------------------------------------------------------*/
36
37 #include <string.h>
38
39 #include <mLib/bits.h>
40
41 /*----- Macros ------------------------------------------------------------*/
42
43 /* --- @HASH_BUFFER@ --- *
44 *
45 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
46 * @ictx@ = pointer to context block for the hash
47 * @ibuf@ = pointer to input data to hash
48 * @isz@ = size of buffer
49 *
50 * Use: Handles buffering of input data to a hash function. The
51 * hash's compression function is called when the buffer is
52 * full. Note that the compression function can be called on
53 * data which is at odd alignments; it is expected to cope
54 * gracefully with this (possibly by copying the data into its
55 * internal buffer before starting).
56 */
57
58 #define HASH_BUFFER(PRE, pre, ictx, ibuf, isz) do { \
59 pre##_ctx *_bctx = (ictx); \
60 size_t _bsz = (isz); \
61 const octet *_bbuf = (octet *)(ibuf); \
62 \
63 /* --- Add on the size done so far --- * \
64 * \
65 * Messy, because trapping overflow is difficult when you don't know \
66 * how many bits you've actually got. \
67 */ \
68 \
69 { \
70 uint32 _l = U32(_bsz); \
71 uint32 _h = ((_bsz & ~MASK32) >> 16) >> 16; \
72 _bctx->nh += _h; \
73 _bctx->nl += _l; \
74 if (_bctx->nl < _l || _bctx->nl & ~MASK32) \
75 _bctx->nh++; \
76 } \
77 \
78 /* --- Handle very small contributions --- */ \
79 \
80 if (_bctx->off + _bsz < PRE##_BUFSZ) { \
81 memcpy(_bctx->buf + _bctx->off, _bbuf, _bsz); \
82 _bctx->off += _bsz; \
83 } else { \
84 \
85 /* --- Handle an initial partial buffer --- */ \
86 \
87 if (_bctx->off) { \
88 size_t s = PRE##_BUFSZ - _bctx->off; \
89 memcpy(_bctx->buf + _bctx->off, _bbuf, s); \
90 pre##_compress(_bctx, _bctx->buf); \
91 _bsz -= s; _bbuf += s; \
92 } \
93 \
94 /* --- Do whole buffers while we can --- */ \
95 \
96 while (_bsz >= PRE##_BUFSZ) { \
97 pre##_compress(_bctx, _bbuf); \
98 _bsz -= PRE##_BUFSZ; _bbuf += PRE##_BUFSZ; \
99 } \
100 \
101 /* --- And wrap up at the end --- */ \
102 \
103 if (_bsz) \
104 memcpy(_bctx->buf, _bbuf, _bsz); \
105 _bctx->off = _bsz; \
106 } \
107 } while (0)
108
109 /* --- @HASH_PAD@ --- *
110 *
111 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
112 * @ictx@ = pointer to context block for the hash
113 * @term@ = terminator character to write following the data
114 * @pad@ = pad character to fill with
115 * @diff@ = size of space to leave at the end of the last block
116 *
117 * Use: Does padding for message digest functions.
118 */
119
120 #define HASH_PAD(PRE, pre, ictx, term, pad, diff) do { \
121 pre##_ctx *_pctx = (ictx); \
122 \
123 _pctx->buf[_pctx->off] = term; \
124 _pctx->off++; \
125 if (_pctx->off > PRE##_BUFSZ - diff) { \
126 if (_pctx->off < PRE##_BUFSZ) \
127 memset(_pctx->buf + _pctx->off, pad, PRE##_BUFSZ - _pctx->off); \
128 pre##_compress(_pctx, _pctx->buf); \
129 memset(_pctx->buf, pad, PRE##_BUFSZ - diff); \
130 } else \
131 memset(_pctx->buf + _pctx->off, pad, \
132 PRE##_BUFSZ - _pctx->off - diff); \
133 } while (0)
134
135 /* --- @HASH_MD5STRENGTH@ --- *
136 *
137 * Arguments: @PRE@, @pre@ = prefixes for hash-specific definitions
138 * @ictx@ = pointer to context block for the hash
139 *
140 * Use: Does MD5-style MD strengthening. The data is terminated
141 * by a single set bit, padded with zero bits, and then a 64-
142 * bit length is written, little-end first.
143 */
144
145 #define HASH_MD5STRENGTH(PRE, pre, ictx) do { \
146 pre##_ctx *_mctx = (ictx); \
147 HASH_PAD(PRE, pre, _mctx, 0x80u, 0, 8); \
148 STORE32_L(_mctx->buf + PRE##_BUFSZ - 8, _mctx->nl << 3); \
149 STORE32_L(_mctx->buf + PRE##_BUFSZ - 4, \
150 (_mctx->nl >> 29) | (_mctx->nh << 3)); \
151 pre##_compress(_mctx, _mctx->buf); \
152 } while (0)
153
154 /* --- @HASH_TEST@ --- *
155 *
156 * Arguments: @PRE@, @pre@ = prefixes for hash-specfic definitions
157 *
158 * Use: Standard test rig for hash functions.
159 */
160
161 #ifdef TEST_RIG
162
163 #include <mLib/quis.h>
164 #include <mLib/testrig.h>
165
166 #define HASH_BUFLEN 100000
167
168 #define HASH_TEST(PRE, pre) \
169 \
170 static int verify(dstr *v) \
171 { \
172 pre##_ctx ctx; \
173 int ok = 1; \
174 int i; \
175 octet *p; \
176 int szs[] = { 1, 7, 192, -1, 0 }, *ip; \
177 size_t sz; \
178 dstr d; \
179 \
180 dstr_create(&d); \
181 dstr_ensure(&d, PRE##_HASHSZ); \
182 d.len = PRE##_HASHSZ; \
183 \
184 for (ip = szs; *ip; ip++) { \
185 i = *ip; \
186 sz = v[0].len; \
187 if (i == -1) \
188 i = sz; \
189 if (i > sz) \
190 continue; \
191 p = (octet *)v[0].buf; \
192 pre##_init(&ctx); \
193 while (sz) { \
194 if (i > sz) \
195 i = sz; \
196 pre##_hash(&ctx, p, i); \
197 p += i; \
198 sz -= i; \
199 } \
200 pre##_done(&ctx, d.buf); \
201 if (memcmp(d.buf, v[1].buf, PRE##_HASHSZ) != 0) { \
202 printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\texpected = ", \
203 *ip, v[0].buf); \
204 type_hex.dump(&v[1], stdout); \
205 fputs("\n\tcomputed = ", stdout); \
206 type_hex.dump(&d, stdout); \
207 putchar('\n'); \
208 ok = 0; \
209 } \
210 } \
211 \
212 dstr_destroy(&d); \
213 return (ok); \
214 } \
215 \
216 static int verifyrep(dstr *v) \
217 { \
218 pre##_ctx ctx; \
219 size_t len = v[0].len; \
220 int n = *(int *)v[1].buf; \
221 int nd = 0; \
222 int nn = len; \
223 int ok = 1; \
224 octet *p, *q; \
225 dstr d = DSTR_INIT; \
226 \
227 while (nn < HASH_BUFLEN && (n & 1) == 0) { nd++; nn <<= 1; n >>= 1; } \
228 p = xmalloc(nn); \
229 memcpy(p, v[0].buf, len); \
230 q = p + len; \
231 while (nd--) { memcpy(q, p, len); q += len; len <<= 1; } \
232 \
233 dstr_ensure(&d, PRE##_HASHSZ); \
234 d.len = PRE##_HASHSZ; \
235 pre##_init(&ctx); \
236 while (n--) pre##_hash(&ctx, p, len); \
237 pre##_done(&ctx, d.buf); \
238 \
239 if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) { \
240 printf("\nfail:\n\tinput = `%s'\n\treps = `%i'\n\texpected = ", \
241 v[0].buf, *(int *)v[1].buf); \
242 type_hex.dump(&v[2], stdout); \
243 fputs("\n\tcomputed = ", stdout); \
244 type_hex.dump(&d, stdout); \
245 putchar('\n'); \
246 ok = 0; \
247 } \
248 xfree(p); \
249 dstr_destroy(&d); \
250 return (ok); \
251 } \
252 \
253 static test_chunk defs[] = { \
254 { #pre, verify, { &type_string, &type_hex, 0 } }, \
255 { #pre "-rep", verifyrep, \
256 { &type_string, &type_int, &type_hex, 0 } }, \
257 { 0, 0, { 0 } } \
258 }; \
259 \
260 int main(int argc, char *argv[]) \
261 { \
262 ego(argv[0]); \
263 test_run(argc, argv, defs, SRCDIR"/t/" #pre); \
264 return (0); \
265 }
266
267 #else
268 # define HASH_TEST(PRE, pre)
269 #endif
270
271 /*----- That's all, folks -------------------------------------------------*/
272
273 #ifdef __cplusplus
274 }
275 #endif
276
277 #endif
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)