3 * Definitions for the MGF-1 mask generator
5 * (c) 2000 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
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.
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.
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,
28 #ifndef CATACOMB_MGF_DEF_H
29 #define CATACOMB_MGF_DEF_H
35 /*----- Header files ------------------------------------------------------*/
41 #include <mLib/bits.h>
44 #ifndef CATACOMB_ARENA_H
48 #ifndef CATACOMB_GCIPHER_H
52 #ifndef CATACOMB_GRAND_H
56 #ifndef CATACOMB_PARANOIA_H
57 # include "paranoia.h"
60 /*----- Macros ------------------------------------------------------------*/
62 #define MGF_DEF(PRE, pre) MGF_DEFX(PRE, pre, #pre, #pre)
64 #define MGF_DEFX(PRE, pre, name, fname) \
66 /* --- Useful constants --- */ \
68 const octet pre##_mgfkeysz[] = { KSZ_ANY, PRE##_HASHSZ }; \
70 /* --- @pre_mgfkeybegin@, @pre_mgfkeyadd@ --- * \
72 * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \
73 * @const void *p@ = pointer to data to contribute \
77 * Use: A multi-step keying procedure for initializing an MGF \
78 * context. The data is contributed to a hashing context \
79 * which is then used for mask generation. If you only \
80 * have a fixed buffer, you can save a lot of effort by \
81 * simply calling @pre_mgfinit@. \
84 void pre##_mgfkeybegin(pre##_mgfctx *k) \
85 { k->c = 0; k->off = 0; pre##_init(&k->k); } \
87 void pre##_mgfkeyadd(pre##_mgfctx *k, const void *p, size_t sz) \
88 { pre##_hash(&k->k, p, sz); } \
90 /* ---- @pre_mgfinit@ --- * \
92 * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \
93 * @const void *p@ = pointer to data to contribute \
94 * @size_t sz@ = size of data to contribute \
98 * Use: A simpler interface to initialization if all of your \
99 * keying material is in one place. \
102 void pre##_mgfinit(pre##_mgfctx *k, const void *p, size_t sz) \
103 { k->c = 0; k->off = 0; pre##_init(&k->k); pre##_hash(&k->k, p, sz); } \
105 /* --- @pre_mgfencrypt@ --- * \
107 * Arguments: @pre_mgfctx *k@ = pointer to masking context \
108 * @const void *s@ = pointer to source buffer \
109 * @void *d@ = pointer to destination buffer \
110 * @size_t sz@ = size of buffers \
114 * Use: Outputs pseudorandom data, or masks an input buffer. \
116 * If @s@ is nonzero, the source material is exclusive- \
117 * orred with the generated mask. If @d@ is zero, the \
118 * generator is simply spun around for a while, which \
119 * isn't very useful. \
122 void pre##_mgfencrypt(pre##_mgfctx *k, const void *s, \
123 void *d, size_t sz) \
126 const octet *ss = s; \
131 /* --- Empty the buffer if there's anything there --- */ \
134 p = k->b + PRE##_HASHSZ - k->off; \
135 off = sz > k->off ? k->off : sz; \
136 sz -= off; k->off -= off; \
137 if (!dd) /* do nothing */; \
138 else if (!ss) { memcpy(dd, p, off); dd += off; } \
139 else while (off--) *dd++ = *ss++ ^ *p++; \
142 /* --- While necessary, generate some more mask --- */ \
145 STORE32(k->b, k->c); k->c++; \
146 h = k->k; pre##_hash(&h, k->b, 4); pre##_done(&h, k->b); \
147 off = sz > PRE##_HASHSZ ? PRE##_HASHSZ : sz; \
148 k->off = PRE##_HASHSZ - off; \
151 if (!dd) /* do nothing */; \
152 else if (!ss) { memcpy(dd, p, off); dd += off; } \
153 else while (off--) *dd++ = *ss++ ^ *p++; \
157 /* --- @pre_mgfsetindex@ --- * \
159 * Arguments: @pre_mgfctx *k@ = pointer to masking context \
160 * @uint32 *c@ = new index to set \
164 * Use: Sets a new index. This may be used to step around the \
165 * output stream in a rather crude way. \
168 void pre##_mgfsetindex(pre##_mgfctx *k, uint32 c) \
169 { k->c = c; k->off = 0; } \
171 /* --- Generic cipher interface --- */ \
173 static const gcipher_ops gops; \
175 typedef struct gctx { \
180 static gcipher *ginit(const void *k, size_t sz) \
182 gctx *g = S_CREATE(gctx); \
184 pre##_mgfinit(&g->k, k, sz); \
188 static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \
189 { gctx *g = (gctx *)c; pre##_mgfencrypt(&g->k, s, t, sz); } \
191 static void gdestroy(gcipher *c) \
192 { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); } \
194 static const gcipher_ops gops = { \
196 gencrypt, gencrypt, gdestroy, 0, 0 \
199 const gccipher pre##_mgf = { \
200 name "-mgf", pre##_mgfkeysz, 0, \
204 /* --- Generic random number generator interface --- */ \
206 typedef struct grctx { \
211 static void grdestroy(grand *r) \
213 grctx *g = (grctx *)r; \
218 static int grmisc(grand *r, unsigned op, ...) \
220 grctx *g = (grctx *)r; \
227 switch (va_arg(ap, unsigned)) { \
229 case GRAND_SEEDINT: \
230 case GRAND_SEEDUINT32: \
231 case GRAND_SEEDBLOCK: \
232 case GRAND_SEEDRAND: \
240 case GRAND_SEEDINT: \
241 pre##_mgfsetindex(&g->k, va_arg(ap, unsigned)); \
243 case GRAND_SEEDUINT32: \
244 pre##_mgfsetindex(&g->k, va_arg(ap, uint32)); \
246 case GRAND_SEEDBLOCK: { \
247 const void *p = va_arg(ap, const void *); \
248 size_t sz = va_arg(ap, size_t); \
249 pre##_hash(&g->k.k, p, sz); \
251 case GRAND_SEEDRAND: { \
252 octet buf[PRE##_BUFSZ]; \
253 grand *rr = va_arg(ap, grand *); \
254 rr->ops->fill(rr, buf, sizeof(buf)); \
255 pre##_hash(&g->k.k, buf, sizeof(buf)); \
266 static octet grbyte(grand *r) \
268 grctx *g = (grctx *)r; \
270 pre##_mgfencrypt(&g->k, 0, &o, 1); \
274 static uint32 grword(grand *r) \
276 grctx *g = (grctx *)r; \
278 pre##_mgfencrypt(&g->k, 0, b, sizeof(b)); \
279 return (LOAD32(b)); \
282 static void grfill(grand *r, void *p, size_t sz) \
283 { grctx *g = (grctx *)r; pre##_mgfencrypt(&g->k, 0, p, sz); } \
285 static const grand_ops grops = { \
289 grword, grbyte, grword, grand_defaultrange, grfill \
292 /* --- @pre_mgfrand@ --- * \
294 * Arguments: @const void *k@ = pointer to key material \
295 * @size_t sz@ = size of key material \
297 * Returns: Pointer to a generic random number generator instance. \
299 * Use: Creates a random number interface wrapper around an \
300 * MGF-1-mode hash function. \
303 extern grand *pre##_mgfrand(const void *k, size_t sz) \
305 grctx *g = S_CREATE(grctx); \
307 pre##_mgfinit(&g->k, k, sz); \
311 MGF_TESTX(PRE, pre, name, fname)
313 /*----- Test rig ----------------------------------------------------------*/
315 #define MGF_TEST(PRE, pre) MGF_TESTX(PRE, pre, #pre, #pre)
319 #include "modes-test.h"
321 /* --- @MGF_TEST@ --- *
323 * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
325 * Use: Standard test rig for MGF functions.
328 #define MGF_TESTX(PRE, pre, name, fname) \
330 static pre##_mgfctx ctx; \
332 static void pre##_mgf_test_setup(const octet *k, size_t ksz) \
333 { pre##_mgfinit(&ctx, k, ksz); } \
335 static void pre##_mgf_test_reset(const octet *iv) \
336 { pre##_mgfsetindex(&ctx, 0); } \
338 static void pre##_mgf_test_enc(const octet *s, octet *d, size_t sz) \
339 { pre##_mgfencrypt(&ctx, s, d, sz); } \
341 int main(int argc, char *argv[]) \
343 return test_encmode(fname "-mgf", 0, PRE##_HASHSZ, 1, 0, \
344 pre##_mgf_test_setup, pre##_mgf_test_reset, \
345 pre##_mgf_test_enc, pre##_mgf_test_enc, \
350 # define MGF_TESTX(PRE, pre, name, fname)
353 /*----- That's all, folks -------------------------------------------------*/