Commit | Line | Data |
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79ba130c | 1 | /* -*-c-*- |
79ba130c | 2 | * |
3 | * Definitions for output feedback mode | |
4 | * | |
5 | * (c) 1999 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
79ba130c | 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. | |
45c0fd36 | 16 | * |
79ba130c | 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. | |
45c0fd36 | 21 | * |
79ba130c | 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 | ||
79ba130c | 28 | #ifndef CATACOMB_OFB_DEF_H |
29 | #define CATACOMB_OFB_DEF_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | #include <stdarg.h> | |
38 | #include <string.h> | |
39 | ||
40 | #include <mLib/bits.h> | |
41 | #include <mLib/sub.h> | |
42 | ||
2af20fa2 | 43 | #ifndef CATACOMB_ARENA_H |
44 | # include "arena.h" | |
45 | #endif | |
46 | ||
79ba130c | 47 | #ifndef CATACOMB_BLKC_H |
48 | # include "blkc.h" | |
49 | #endif | |
50 | ||
51 | #ifndef CATACOMB_GCIPHER_H | |
52 | # include "gcipher.h" | |
53 | #endif | |
54 | ||
55 | #ifndef CATACOMB_PARANOIA_H | |
56 | # include "paranoia.h" | |
57 | #endif | |
58 | ||
6a0eb244 MW |
59 | #ifndef CATACOMB_RSVR_H |
60 | # include "rsvr.h" | |
61 | #endif | |
62 | ||
79ba130c | 63 | /*----- Macros ------------------------------------------------------------*/ |
64 | ||
65 | /* --- @OFB_DEF@ --- * | |
66 | * | |
67 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher | |
68 | * | |
69 | * Use: Creates definitions for output feedback mode. | |
70 | */ | |
71 | ||
aaae9cab MW |
72 | #define OFB_DEF(PRE, pre) OFB_DEFX(PRE, pre, #pre, #pre) |
73 | ||
74 | #define OFB_DEFX(PRE, pre, name, fname) \ | |
79ba130c | 75 | \ |
76 | /* --- @pre_ofbgetiv@ --- * \ | |
77 | * \ | |
78 | * Arguments: @const pre_ofbctx *ctx@ = pointer to OFB context block \ | |
4efe32ba | 79 | * @void *iv@ = pointer to output data block \ |
79ba130c | 80 | * \ |
81 | * Returns: --- \ | |
82 | * \ | |
83 | * Use: Reads the currently set IV. Reading and setting an IV \ | |
84 | * is not transparent to the cipher. It will add a `step' \ | |
85 | * which must be matched by a similar operation during \ | |
86 | * decryption. \ | |
87 | */ \ | |
88 | \ | |
89 | void pre##_ofbgetiv(const pre##_ofbctx *ctx, void *iv) \ | |
90 | { \ | |
91 | octet *p = iv; \ | |
2af20fa2 | 92 | unsigned off = ctx->off; \ |
93 | unsigned rest = PRE##_BLKSZ - off; \ | |
0fee61eb MW |
94 | \ |
95 | memcpy(p, ctx->b + off, rest); \ | |
96 | memcpy(p + rest, ctx->b, off); \ | |
79ba130c | 97 | } \ |
98 | \ | |
99 | /* --- @pre_ofbsetiv@ --- * \ | |
100 | * \ | |
101 | * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \ | |
102 | * @cnost void *iv@ = pointer to IV to set \ | |
103 | * \ | |
104 | * Returns: --- \ | |
105 | * \ | |
106 | * Use: Sets the IV to use for subsequent encryption. \ | |
107 | */ \ | |
108 | \ | |
109 | void pre##_ofbsetiv(pre##_ofbctx *ctx, const void *iv) \ | |
6a0eb244 | 110 | { memcpy(ctx->b, iv, PRE##_BLKSZ); ctx->off = 0; } \ |
79ba130c | 111 | \ |
112 | /* --- @pre_ofbbdry@ --- * \ | |
113 | * \ | |
114 | * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \ | |
115 | * \ | |
116 | * Returns: --- \ | |
117 | * \ | |
118 | * Use: Inserts a boundary during encryption. Successful \ | |
119 | * decryption must place a similar boundary. \ | |
120 | */ \ | |
121 | \ | |
122 | void pre##_ofbbdry(pre##_ofbctx *ctx) \ | |
123 | { \ | |
0fee61eb MW |
124 | uint32 t[PRE##_BLKSZ/4]; \ |
125 | \ | |
126 | BLKC_LOAD(PRE, t, ctx->b); \ | |
127 | pre##_eblk(&ctx->ctx, t, t); \ | |
128 | BLKC_STORE(PRE, ctx->b, t); \ | |
6a0eb244 | 129 | ctx->off = 0; \ |
0fee61eb | 130 | BURN(t); \ |
79ba130c | 131 | } \ |
132 | \ | |
133 | /* --- @pre_ofbsetkey@ --- * \ | |
134 | * \ | |
135 | * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \ | |
136 | * @const pre_ctx *k@ = pointer to cipher context \ | |
137 | * \ | |
138 | * Returns: --- \ | |
139 | * \ | |
140 | * Use: Sets the OFB context to use a different cipher key. \ | |
141 | */ \ | |
142 | \ | |
143 | void pre##_ofbsetkey(pre##_ofbctx *ctx, const pre##_ctx *k) \ | |
0fee61eb | 144 | { ctx->ctx = *k; } \ |
79ba130c | 145 | \ |
146 | /* --- @pre_ofbinit@ --- * \ | |
147 | * \ | |
148 | * Arguments: @pre_ofbctx *ctx@ = pointer to cipher context \ | |
149 | * @const void *key@ = pointer to the key buffer \ | |
150 | * @size_t sz@ = size of the key \ | |
151 | * @const void *iv@ = pointer to initialization vector \ | |
152 | * \ | |
153 | * Returns: --- \ | |
154 | * \ | |
155 | * Use: Initializes a OFB context ready for use. You should \ | |
156 | * ensure that the IV chosen is unique: reusing an IV will \ | |
157 | * compromise the security of the entire plaintext. This \ | |
158 | * is equivalent to calls to @pre_init@, @pre_ofbsetkey@ \ | |
159 | * and @pre_ofbsetiv@. \ | |
160 | */ \ | |
161 | \ | |
162 | void pre##_ofbinit(pre##_ofbctx *ctx, \ | |
163 | const void *key, size_t sz, \ | |
164 | const void *iv) \ | |
165 | { \ | |
4e66da02 | 166 | static const octet zero[PRE##_BLKSZ] = { 0 }; \ |
0fee61eb | 167 | \ |
79ba130c | 168 | pre##_init(&ctx->ctx, key, sz); \ |
169 | pre##_ofbsetiv(ctx, iv ? iv : zero); \ | |
170 | } \ | |
171 | \ | |
172 | /* --- @pre_ofbencrypt@ --- * \ | |
173 | * \ | |
174 | * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \ | |
175 | * @const void *src@ = pointer to source data \ | |
176 | * @void *dest@ = pointer to destination data \ | |
177 | * @size_t sz@ = size of block to be encrypted \ | |
178 | * \ | |
179 | * Returns: --- \ | |
180 | * \ | |
181 | * Use: Encrypts or decrypts a block with a block cipher in OFB \ | |
182 | * mode: encryption and decryption are the same in OFB. \ | |
183 | * The destination may be null to just churn the feedback \ | |
184 | * round for a bit. The source may be null to use the \ | |
185 | * cipher as a random data generator. \ | |
186 | */ \ | |
187 | \ | |
6a0eb244 MW |
188 | static const rsvr_policy pre##_ofbpolicy = { 0, PRE##_BLKSZ, PRE##_BLKSZ }; \ |
189 | \ | |
79ba130c | 190 | void pre##_ofbencrypt(pre##_ofbctx *ctx, \ |
81b52866 MW |
191 | const void *src, void *dest, \ |
192 | size_t sz) \ | |
79ba130c | 193 | { \ |
6a0eb244 MW |
194 | rsvr_plan plan; \ |
195 | const octet *s = src, *p; \ | |
79ba130c | 196 | octet *d = dest; \ |
0fee61eb | 197 | uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ/4]; \ |
79ba130c | 198 | \ |
6a0eb244 MW |
199 | /* Construct a plan and prepare to follow through. */ \ |
200 | rsvr_mkplan(&plan, &pre##_ofbpolicy, ctx->off, sz); \ | |
0fee61eb | 201 | BLKC_LOAD(PRE, t, ctx->b); \ |
79ba130c | 202 | \ |
6a0eb244 MW |
203 | /* Initial portion, fulfilled from the buffer. If the chunk is small \ |
204 | * enough, then this will be the only portion. If the buffer is \ | |
205 | * currently empty, then we must prepare it. \ | |
206 | */ \ | |
207 | if (plan.head) { \ | |
208 | if (!ctx->off) { \ | |
209 | pre##_eblk(&ctx->ctx, t, t); \ | |
210 | BLKC_STORE(PRE, ctx->b, t); \ | |
0fee61eb | 211 | } \ |
6a0eb244 MW |
212 | p = ctx->b + ctx->off; ctx->off += plan.head; \ |
213 | if (!d) /* nothing to do */; \ | |
214 | else if (!s) { memcpy(d, p, plan.head); d += plan.head; } \ | |
215 | else while (plan.head--) *d++ = *s++ ^ *p++; \ | |
79ba130c | 216 | } \ |
217 | \ | |
6a0eb244 MW |
218 | /* If the buffer is all used, then reset it ready for next time. */ \ |
219 | ctx->off -= plan.from_rsvr; \ | |
0fee61eb | 220 | \ |
6a0eb244 MW |
221 | /* Handle multiple whole blocks. */ \ |
222 | if (!d) while (plan.from_input) { \ | |
223 | pre##_eblk(&ctx->ctx, t, t); \ | |
224 | plan.from_input -= PRE##_BLKSZ; \ | |
225 | } else if (!s) while (plan.from_input) { \ | |
226 | pre##_eblk(&ctx->ctx, t, t); \ | |
227 | BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ; \ | |
228 | plan.from_input -= PRE##_BLKSZ; \ | |
229 | } else while (plan.from_input) { \ | |
230 | pre##_eblk(&ctx->ctx, t, t); \ | |
231 | BLKC_LOAD(PRE, u, s); s += PRE##_BLKSZ; \ | |
232 | BLKC_XSTORE(PRE, d, t, u); d += PRE##_BLKSZ; \ | |
233 | plan.from_input -= PRE##_BLKSZ; \ | |
79ba130c | 234 | } \ |
235 | \ | |
6a0eb244 MW |
236 | /* Final portion. Note that the buffer must be empty if there is a \ |
237 | * tail, since otherwise the input data would have been part of the \ | |
238 | * head portion instad. */ \ | |
239 | if (!plan.tail) \ | |
240 | BLKC_STORE(PRE, ctx->b, t); \ | |
241 | else { \ | |
242 | pre##_eblk(&ctx->ctx, t, t); \ | |
243 | BLKC_STORE(PRE, ctx->b, t); \ | |
244 | p = ctx->b; ctx->off += plan.tail; \ | |
245 | if (!d) /* nothing to do */; \ | |
246 | else if (!s) { memcpy(d, p, plan.tail); d += plan.tail; } \ | |
247 | else while (plan.tail--) *d++ = *s++ ^ *p++; \ | |
248 | } \ | |
79ba130c | 249 | } \ |
250 | \ | |
251 | /* --- Generic cipher interface --- */ \ | |
252 | \ | |
253 | static const gcipher_ops gops; \ | |
254 | \ | |
255 | typedef struct gctx { \ | |
256 | gcipher c; \ | |
257 | pre##_ofbctx k; \ | |
258 | } gctx; \ | |
259 | \ | |
260 | static gcipher *ginit(const void *k, size_t sz) \ | |
261 | { \ | |
2af20fa2 | 262 | gctx *g = S_CREATE(gctx); \ |
79ba130c | 263 | g->c.ops = &gops; \ |
264 | pre##_ofbinit(&g->k, k, sz, 0); \ | |
265 | return (&g->c); \ | |
266 | } \ | |
267 | \ | |
268 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ | |
0fee61eb | 269 | { gctx *g = (gctx *)c; pre##_ofbencrypt(&g->k, s, t, sz); } \ |
79ba130c | 270 | \ |
271 | static void gdestroy(gcipher *c) \ | |
0fee61eb | 272 | { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); } \ |
79ba130c | 273 | \ |
274 | static void gsetiv(gcipher *c, const void *iv) \ | |
0fee61eb | 275 | { gctx *g = (gctx *)c; pre##_ofbsetiv(&g->k, iv); } \ |
79ba130c | 276 | \ |
277 | static void gbdry(gcipher *c) \ | |
278 | { \ | |
279 | gctx *g = (gctx *)c; \ | |
280 | pre##_ofbbdry(&g->k); \ | |
281 | } \ | |
282 | \ | |
283 | static const gcipher_ops gops = { \ | |
2af20fa2 | 284 | &pre##_ofb, \ |
79ba130c | 285 | gencrypt, gencrypt, gdestroy, gsetiv, gbdry \ |
286 | }; \ | |
287 | \ | |
288 | const gccipher pre##_ofb = { \ | |
aaae9cab | 289 | name "-ofb", pre##_keysz, PRE##_BLKSZ, \ |
79ba130c | 290 | ginit \ |
291 | }; \ | |
292 | \ | |
293 | /* --- Generic random number generator interface --- */ \ | |
294 | \ | |
295 | typedef struct grctx { \ | |
296 | grand r; \ | |
297 | pre##_ofbctx k; \ | |
298 | } grctx; \ | |
299 | \ | |
300 | static void grdestroy(grand *r) \ | |
0fee61eb | 301 | { grctx *g = (grctx *)r; BURN(*g); S_DESTROY(g); } \ |
79ba130c | 302 | \ |
303 | static int grmisc(grand *r, unsigned op, ...) \ | |
304 | { \ | |
305 | grctx *g = (grctx *)r; \ | |
306 | va_list ap; \ | |
307 | int rc = 0; \ | |
360c232e | 308 | uint32 i; \ |
79ba130c | 309 | octet buf[PRE##_BLKSZ]; \ |
310 | va_start(ap, op); \ | |
311 | \ | |
312 | switch (op) { \ | |
313 | case GRAND_CHECK: \ | |
314 | switch (va_arg(ap, unsigned)) { \ | |
315 | case GRAND_CHECK: \ | |
316 | case GRAND_SEEDINT: \ | |
317 | case GRAND_SEEDUINT32: \ | |
318 | case GRAND_SEEDBLOCK: \ | |
4ab1268f | 319 | case GRAND_SEEDRAND: \ |
79ba130c | 320 | rc = 1; \ |
321 | break; \ | |
322 | default: \ | |
323 | rc = 0; \ | |
324 | break; \ | |
325 | } \ | |
326 | break; \ | |
327 | case GRAND_SEEDINT: \ | |
328 | memset(buf, 0, sizeof(buf)); \ | |
360c232e | 329 | i = va_arg(ap, unsigned); \ |
330 | STORE32(buf, i); \ | |
79ba130c | 331 | pre##_ofbsetiv(&g->k, buf); \ |
332 | break; \ | |
333 | case GRAND_SEEDUINT32: \ | |
334 | memset(buf, 0, sizeof(buf)); \ | |
360c232e | 335 | i = va_arg(ap, uint32); \ |
336 | STORE32(buf, i); \ | |
79ba130c | 337 | pre##_ofbsetiv(&g->k, buf); \ |
338 | break; \ | |
339 | case GRAND_SEEDBLOCK: { \ | |
340 | const void *p = va_arg(ap, const void *); \ | |
341 | size_t sz = va_arg(ap, size_t); \ | |
342 | if (sz < sizeof(buf)) { \ | |
343 | memset(buf, 0, sizeof(buf)); \ | |
344 | memcpy(buf, p, sz); \ | |
345 | p = buf; \ | |
346 | } \ | |
347 | pre##_ofbsetiv(&g->k, p); \ | |
348 | } break; \ | |
4ab1268f | 349 | case GRAND_SEEDRAND: { \ |
350 | grand *rr = va_arg(ap, grand *); \ | |
351 | rr->ops->fill(rr, buf, sizeof(buf)); \ | |
352 | pre##_ofbsetiv(&g->k, buf); \ | |
353 | } break; \ | |
354 | default: \ | |
355 | GRAND_BADOP; \ | |
356 | break; \ | |
79ba130c | 357 | } \ |
358 | \ | |
359 | va_end(ap); \ | |
360 | return (rc); \ | |
361 | } \ | |
362 | \ | |
363 | static octet grbyte(grand *r) \ | |
364 | { \ | |
365 | grctx *g = (grctx *)r; \ | |
366 | octet o; \ | |
367 | pre##_ofbencrypt(&g->k, 0, &o, 1); \ | |
368 | return (o); \ | |
369 | } \ | |
370 | \ | |
371 | static uint32 grword(grand *r) \ | |
372 | { \ | |
373 | grctx *g = (grctx *)r; \ | |
374 | octet b[4]; \ | |
375 | pre##_ofbencrypt(&g->k, 0, b, sizeof(b)); \ | |
376 | return (LOAD32(b)); \ | |
377 | } \ | |
378 | \ | |
379 | static void grfill(grand *r, void *p, size_t sz) \ | |
0fee61eb | 380 | { grctx *g = (grctx *)r; pre##_ofbencrypt(&g->k, 0, p, sz); } \ |
79ba130c | 381 | \ |
382 | static const grand_ops grops = { \ | |
aaae9cab | 383 | name "-ofb", \ |
2af20fa2 | 384 | GRAND_CRYPTO, 0, \ |
79ba130c | 385 | grmisc, grdestroy, \ |
44ff6c11 | 386 | grword, grbyte, grword, grand_defaultrange, grfill \ |
79ba130c | 387 | }; \ |
388 | \ | |
389 | /* --- @pre_ofbrand@ --- * \ | |
390 | * \ | |
391 | * Arguments: @const void *k@ = pointer to key material \ | |
392 | * @size_t sz@ = size of key material \ | |
393 | * \ | |
394 | * Returns: Pointer to generic random number generator interface. \ | |
395 | * \ | |
396 | * Use: Creates a random number interface wrapper around an \ | |
397 | * OFB-mode block cipher. \ | |
398 | */ \ | |
399 | \ | |
400 | grand *pre##_ofbrand(const void *k, size_t sz) \ | |
401 | { \ | |
2af20fa2 | 402 | grctx *g = S_CREATE(grctx); \ |
79ba130c | 403 | g->r.ops = &grops; \ |
404 | pre##_ofbinit(&g->k, k, sz, 0); \ | |
405 | return (&g->r); \ | |
406 | } \ | |
407 | \ | |
aaae9cab | 408 | OFB_TESTX(PRE, pre, name, name) |
79ba130c | 409 | |
410 | /*----- Test rig ----------------------------------------------------------*/ | |
411 | ||
aaae9cab MW |
412 | #define OFB_TEST(PRE, pre) OFB_TESTX(PRE, pre, #pre, #pre) |
413 | ||
79ba130c | 414 | #ifdef TEST_RIG |
415 | ||
57f459eb | 416 | #include "modes-test.h" |
79ba130c | 417 | |
418 | /* --- @OFB_TEST@ --- * | |
419 | * | |
420 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions | |
421 | * | |
422 | * Use: Standard test rig for OFB functions. | |
423 | */ | |
424 | ||
81b52866 | 425 | #define OFB_TESTX(PRE, pre, name, fname) \ |
79ba130c | 426 | \ |
57f459eb MW |
427 | static pre##_ctx key; \ |
428 | static pre##_ofbctx ctx; \ | |
79ba130c | 429 | \ |
57f459eb MW |
430 | static void pre##_ofb_test_setup(const octet *k, size_t ksz) \ |
431 | { pre##_init(&key, k, ksz); pre##_ofbsetkey(&ctx, &key); } \ | |
79ba130c | 432 | \ |
57f459eb MW |
433 | static void pre##_ofb_test_reset(const octet *iv) \ |
434 | { pre##_ofbsetiv(&ctx, iv); } \ | |
79ba130c | 435 | \ |
57f459eb MW |
436 | static void pre##_ofb_test_enc(const octet *s, octet *d, size_t sz) \ |
437 | { pre##_ofbencrypt(&ctx, s, d, sz); } \ | |
79ba130c | 438 | \ |
57f459eb | 439 | int main(int argc, char *argv[]) \ |
79ba130c | 440 | { \ |
57f459eb MW |
441 | return test_encmode(fname "-ofb", PRE##_KEYSZ, PRE##_BLKSZ, 1, 0, \ |
442 | pre##_ofb_test_setup, pre##_ofb_test_reset, \ | |
443 | pre##_ofb_test_enc, pre##_ofb_test_enc, \ | |
444 | argc, argv); \ | |
79ba130c | 445 | } |
446 | ||
447 | #else | |
aaae9cab | 448 | # define OFB_TESTX(PRE, pre, name, fname) |
79ba130c | 449 | #endif |
450 | ||
451 | /*----- That's all, folks -------------------------------------------------*/ | |
452 | ||
453 | #ifdef __cplusplus | |
454 | } | |
455 | #endif | |
456 | ||
457 | #endif |