Commit | Line | Data |
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35d66180 | 1 | /* -*-c-*- |
2 | * | |
35d66180 | 3 | * Block cipher counter mode (or long cycle mode) |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
35d66180 | 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 | * |
35d66180 | 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 | * |
35d66180 | 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 | ||
35d66180 | 28 | #ifndef CATACOMB_COUNTER_DEF_H |
29 | #define CATACOMB_COUNTER_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 | ||
43 | #ifndef CATACOMB_ARENA_H | |
44 | # include "arena.h" | |
45 | #endif | |
46 | ||
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 | ||
59 | /*----- Macros ------------------------------------------------------------*/ | |
60 | ||
61 | /* --- @COUNTER_DEF@ --- * | |
62 | * | |
63 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher | |
64 | * | |
65 | * Use: Creates definitions for counter mode. | |
66 | */ | |
67 | ||
aaae9cab MW |
68 | #define COUNTER_DEF(PRE, pre) COUNTER_DEFX(PRE, pre, #pre, #pre) |
69 | ||
70 | #define COUNTER_DEFX(PRE, pre, name, fname) \ | |
35d66180 | 71 | \ |
72 | /* --- @pre_countergetiv@ --- * \ | |
73 | * \ | |
74 | * Arguments: @const pre_counterctx *ctx@ = pointer to counter \ | |
75 | * context \ | |
4efe32ba | 76 | * @void *iv@ = pointer to output data block \ |
35d66180 | 77 | * \ |
78 | * Returns: --- \ | |
79 | * \ | |
80 | * Use: Reads the currently set IV. Reading and setting an IV \ | |
81 | * is not transparent to the cipher. It will add a `step' \ | |
82 | * which must be matched by a similar operation during \ | |
83 | * decryption. \ | |
84 | */ \ | |
85 | \ | |
86 | void pre##_countergetiv(const pre##_counterctx *ctx, void *iv) \ | |
0fee61eb | 87 | { BLKC_STORE(PRE, iv, ctx->c); } \ |
35d66180 | 88 | \ |
89 | /* --- @pre_countersetiv@ --- * \ | |
90 | * \ | |
91 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
92 | * @cnost void *iv@ = pointer to IV to set \ | |
93 | * \ | |
94 | * Returns: --- \ | |
95 | * \ | |
96 | * Use: Sets the IV to use for subsequent encryption. \ | |
97 | */ \ | |
98 | \ | |
99 | void pre##_countersetiv(pre##_counterctx *ctx, const void *iv) \ | |
0fee61eb | 100 | { BLKC_LOAD(PRE, ctx->c, iv); ctx->off = PRE##_BLKSZ; } \ |
35d66180 | 101 | \ |
102 | /* --- @pre_counterbdry@ --- * \ | |
103 | * \ | |
104 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
105 | * \ | |
106 | * Returns: --- \ | |
107 | * \ | |
108 | * Use: Inserts a boundary during encryption. Successful \ | |
109 | * decryption must place a similar boundary. \ | |
110 | */ \ | |
111 | \ | |
112 | void pre##_counterbdry(pre##_counterctx *ctx) \ | |
0fee61eb | 113 | { BLKC_STEP(PRE, ctx->c); ctx->off = PRE##_BLKSZ; } \ |
35d66180 | 114 | \ |
115 | /* --- @pre_countersetkey@ --- * \ | |
116 | * \ | |
117 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
118 | * @const pre_ctx *k@ = pointer to cipher context \ | |
119 | * \ | |
120 | * Returns: --- \ | |
121 | * \ | |
122 | * Use: Sets the counter context to use a different cipher key. \ | |
123 | */ \ | |
124 | \ | |
125 | void pre##_countersetkey(pre##_counterctx *ctx, const pre##_ctx *k) \ | |
0fee61eb | 126 | { ctx->ctx = *k; } \ |
35d66180 | 127 | \ |
128 | /* --- @pre_counterinit@ --- * \ | |
129 | * \ | |
130 | * Arguments: @pre_counterctx *ctx@ = pointer to cipher context \ | |
131 | * @const void *key@ = pointer to the key buffer \ | |
132 | * @size_t sz@ = size of the key \ | |
133 | * @const void *iv@ = pointer to initialization vector \ | |
134 | * \ | |
135 | * Returns: --- \ | |
136 | * \ | |
137 | * Use: Initializes a counter context ready for use. You \ | |
138 | * should ensure that the IV chosen is unique: reusing an \ | |
139 | * IV will compromise the security of the entire \ | |
140 | * plaintext. This is equivalent to calls to @pre_init@, \ | |
141 | * @pre_countersetkey@ and @pre_countersetiv@. \ | |
142 | */ \ | |
143 | \ | |
144 | void pre##_counterinit(pre##_counterctx *ctx, \ | |
145 | const void *key, size_t sz, \ | |
146 | const void *iv) \ | |
147 | { \ | |
4e66da02 | 148 | static const octet zero[PRE##_BLKSZ] = { 0 }; \ |
0fee61eb | 149 | \ |
35d66180 | 150 | pre##_init(&ctx->ctx, key, sz); \ |
151 | pre##_countersetiv(ctx, iv ? iv : zero); \ | |
152 | } \ | |
153 | \ | |
154 | /* --- @pre_counterencrypt@ --- * \ | |
155 | * \ | |
156 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
157 | * @const void *src@ = pointer to source data \ | |
158 | * @void *dest@ = pointer to destination data \ | |
159 | * @size_t sz@ = size of block to be encrypted \ | |
160 | * \ | |
161 | * Returns: --- \ | |
162 | * \ | |
163 | * Use: Encrypts or decrypts a block with a block cipher in \ | |
164 | * counter mode: encryption and decryption are the same in \ | |
165 | * counter. The destination may be null to just churn the \ | |
166 | * feedback round for a bit. The source may be null to \ | |
167 | * use the cipher as a random data generator. \ | |
168 | */ \ | |
169 | \ | |
170 | void pre##_counterencrypt(pre##_counterctx *ctx, \ | |
171 | const void *src, void *dest, \ | |
172 | size_t sz) \ | |
173 | { \ | |
174 | const octet *s = src; \ | |
175 | octet *d = dest; \ | |
176 | unsigned off = ctx->off; \ | |
0fee61eb MW |
177 | uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ/4]; \ |
178 | octet y; \ | |
35d66180 | 179 | \ |
180 | /* --- Empty blocks are trivial --- */ \ | |
181 | \ | |
0fee61eb | 182 | if (!sz) return; \ |
35d66180 | 183 | \ |
184 | /* --- If I can deal with the block from my buffer, do that --- */ \ | |
185 | \ | |
0fee61eb | 186 | if (sz < PRE##_BLKSZ - off) goto small; \ |
35d66180 | 187 | \ |
188 | /* --- Finish off what's left in my buffer --- */ \ | |
189 | \ | |
0fee61eb MW |
190 | if (!d) sz -= PRE##_BLKSZ - off; \ |
191 | else while (off < PRE##_BLKSZ) \ | |
192 | { y = s ? *s++ : 0; *d++ = ctx->b[off++] ^ y; sz--; } \ | |
35d66180 | 193 | \ |
194 | /* --- Main encryption loop --- */ \ | |
195 | \ | |
0fee61eb MW |
196 | for (;;) { \ |
197 | pre##_eblk(&ctx->ctx, ctx->c, t); \ | |
198 | BLKC_STEP(PRE, ctx->c); \ | |
199 | if (sz < PRE##_BLKSZ) break; \ | |
200 | if (!d) /* do nothing */; \ | |
201 | else if (!s) { BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ; } \ | |
202 | else { \ | |
203 | BLKC_LOAD(PRE, u, s); s += PRE##_BLKSZ; \ | |
204 | BLKC_XSTORE(PRE, d, t, u); d += PRE##_BLKSZ; \ | |
35d66180 | 205 | } \ |
0fee61eb | 206 | sz -= PRE##_BLKSZ; \ |
35d66180 | 207 | } \ |
208 | \ | |
0fee61eb MW |
209 | BLKC_STORE(PRE, ctx->b, t); \ |
210 | off = 0; \ | |
211 | \ | |
35d66180 | 212 | /* --- Tidying up the tail end --- */ \ |
213 | \ | |
214 | if (sz) { \ | |
215 | small: \ | |
0fee61eb MW |
216 | if (!d) off += sz; \ |
217 | else do { y = s ? *s++ : 0; *d++ = ctx->b[off++] ^ y; sz--; } \ | |
218 | while (sz); \ | |
35d66180 | 219 | } \ |
220 | \ | |
221 | /* --- Done --- */ \ | |
222 | \ | |
223 | ctx->off = off; \ | |
224 | return; \ | |
225 | } \ | |
226 | \ | |
227 | /* --- Generic cipher interface --- */ \ | |
228 | \ | |
229 | static const gcipher_ops gops; \ | |
230 | \ | |
231 | typedef struct gctx { \ | |
232 | gcipher c; \ | |
233 | pre##_counterctx k; \ | |
234 | } gctx; \ | |
235 | \ | |
236 | static gcipher *ginit(const void *k, size_t sz) \ | |
237 | { \ | |
238 | gctx *g = S_CREATE(gctx); \ | |
239 | g->c.ops = &gops; \ | |
240 | pre##_counterinit(&g->k, k, sz, 0); \ | |
241 | return (&g->c); \ | |
242 | } \ | |
243 | \ | |
244 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ | |
0fee61eb | 245 | { gctx *g = (gctx *)c; pre##_counterencrypt(&g->k, s, t, sz); } \ |
35d66180 | 246 | \ |
247 | static void gdestroy(gcipher *c) \ | |
0fee61eb | 248 | { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); } \ |
35d66180 | 249 | \ |
250 | static void gsetiv(gcipher *c, const void *iv) \ | |
0fee61eb | 251 | { gctx *g = (gctx *)c; pre##_countersetiv(&g->k, iv); } \ |
35d66180 | 252 | \ |
253 | static void gbdry(gcipher *c) \ | |
0fee61eb | 254 | { gctx *g = (gctx *)c; pre##_counterbdry(&g->k); } \ |
35d66180 | 255 | \ |
256 | static const gcipher_ops gops = { \ | |
257 | &pre##_counter, \ | |
258 | gencrypt, gencrypt, gdestroy, gsetiv, gbdry \ | |
259 | }; \ | |
260 | \ | |
261 | const gccipher pre##_counter = { \ | |
aaae9cab | 262 | name "-counter", pre##_keysz, PRE##_BLKSZ, \ |
35d66180 | 263 | ginit \ |
264 | }; \ | |
265 | \ | |
266 | /* --- Generic random number generator interface --- */ \ | |
267 | \ | |
268 | typedef struct grctx { \ | |
269 | grand r; \ | |
270 | pre##_counterctx k; \ | |
271 | } grctx; \ | |
272 | \ | |
273 | static void grdestroy(grand *r) \ | |
274 | { \ | |
275 | grctx *g = (grctx *)r; \ | |
276 | BURN(*g); \ | |
277 | S_DESTROY(g); \ | |
278 | } \ | |
279 | \ | |
280 | static int grmisc(grand *r, unsigned op, ...) \ | |
281 | { \ | |
282 | grctx *g = (grctx *)r; \ | |
283 | va_list ap; \ | |
284 | int rc = 0; \ | |
285 | octet buf[PRE##_BLKSZ]; \ | |
286 | va_start(ap, op); \ | |
287 | \ | |
288 | switch (op) { \ | |
289 | case GRAND_CHECK: \ | |
290 | switch (va_arg(ap, unsigned)) { \ | |
291 | case GRAND_CHECK: \ | |
292 | case GRAND_SEEDINT: \ | |
293 | case GRAND_SEEDUINT32: \ | |
294 | case GRAND_SEEDBLOCK: \ | |
295 | case GRAND_SEEDRAND: \ | |
296 | rc = 1; \ | |
297 | break; \ | |
298 | default: \ | |
299 | rc = 0; \ | |
300 | break; \ | |
301 | } \ | |
302 | break; \ | |
303 | case GRAND_SEEDINT: \ | |
0fee61eb | 304 | BLKC_SET(PRE, g->k.c, va_arg(ap, unsigned)); \ |
35d66180 | 305 | g->k.off = PRE##_BLKSZ; \ |
306 | break; \ | |
307 | case GRAND_SEEDUINT32: \ | |
0fee61eb | 308 | BLKC_SET(PRE, g->k.c, va_arg(ap, uint32)); \ |
35d66180 | 309 | g->k.off = PRE##_BLKSZ; \ |
310 | break; \ | |
311 | case GRAND_SEEDBLOCK: { \ | |
312 | const void *p = va_arg(ap, const void *); \ | |
313 | size_t sz = va_arg(ap, size_t); \ | |
314 | if (sz < sizeof(buf)) { \ | |
315 | memset(buf, 0, sizeof(buf)); \ | |
316 | memcpy(buf, p, sz); \ | |
317 | p = buf; \ | |
318 | } \ | |
319 | pre##_countersetiv(&g->k, p); \ | |
320 | } break; \ | |
321 | case GRAND_SEEDRAND: { \ | |
322 | grand *rr = va_arg(ap, grand *); \ | |
323 | rr->ops->fill(rr, buf, sizeof(buf)); \ | |
324 | pre##_countersetiv(&g->k, buf); \ | |
325 | } break; \ | |
326 | default: \ | |
327 | GRAND_BADOP; \ | |
328 | break; \ | |
329 | } \ | |
330 | \ | |
331 | va_end(ap); \ | |
332 | return (rc); \ | |
333 | } \ | |
334 | \ | |
335 | static octet grbyte(grand *r) \ | |
336 | { \ | |
337 | grctx *g = (grctx *)r; \ | |
338 | octet o; \ | |
339 | pre##_counterencrypt(&g->k, 0, &o, 1); \ | |
340 | return (o); \ | |
341 | } \ | |
342 | \ | |
343 | static uint32 grword(grand *r) \ | |
344 | { \ | |
345 | grctx *g = (grctx *)r; \ | |
346 | octet b[4]; \ | |
347 | pre##_counterencrypt(&g->k, 0, b, sizeof(b)); \ | |
348 | return (LOAD32(b)); \ | |
349 | } \ | |
350 | \ | |
351 | static void grfill(grand *r, void *p, size_t sz) \ | |
0fee61eb | 352 | { grctx *g = (grctx *)r; pre##_counterencrypt(&g->k, 0, p, sz); } \ |
35d66180 | 353 | \ |
354 | static const grand_ops grops = { \ | |
aaae9cab | 355 | name "-counter", \ |
35d66180 | 356 | GRAND_CRYPTO, 0, \ |
357 | grmisc, grdestroy, \ | |
44ff6c11 | 358 | grword, grbyte, grword, grand_defaultrange, grfill \ |
35d66180 | 359 | }; \ |
360 | \ | |
361 | /* --- @pre_counterrand@ --- * \ | |
362 | * \ | |
363 | * Arguments: @const void *k@ = pointer to key material \ | |
364 | * @size_t sz@ = size of key material \ | |
365 | * \ | |
366 | * Returns: Pointer to generic random number generator interface. \ | |
367 | * \ | |
368 | * Use: Creates a random number interface wrapper around an \ | |
369 | * counter-mode block cipher. \ | |
370 | */ \ | |
371 | \ | |
372 | grand *pre##_counterrand(const void *k, size_t sz) \ | |
373 | { \ | |
374 | grctx *g = S_CREATE(grctx); \ | |
375 | g->r.ops = &grops; \ | |
376 | pre##_counterinit(&g->k, k, sz, 0); \ | |
377 | return (&g->r); \ | |
378 | } \ | |
379 | \ | |
aaae9cab | 380 | COUNTER_TESTX(PRE, pre, name, fname) |
35d66180 | 381 | |
382 | /*----- Test rig ----------------------------------------------------------*/ | |
383 | ||
aaae9cab MW |
384 | #define COUNTER_TEST(PRE, pre) COUNTER_TESTX(PRE, pre, #pre, #pre) |
385 | ||
35d66180 | 386 | #ifdef TEST_RIG |
387 | ||
57f459eb | 388 | #include "modes-test.h" |
35d66180 | 389 | |
390 | /* --- @COUNTER_TEST@ --- * | |
391 | * | |
392 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions | |
393 | * | |
394 | * Use: Standard test rig for counter functions. | |
395 | */ | |
396 | ||
aaae9cab | 397 | #define COUNTER_TESTX(PRE, pre, name, fname) \ |
35d66180 | 398 | \ |
57f459eb MW |
399 | static pre##_ctx key; \ |
400 | static pre##_counterctx ctx; \ | |
35d66180 | 401 | \ |
57f459eb MW |
402 | static void pre##_counter_test_setup(const octet *k, size_t ksz) \ |
403 | { pre##_init(&key, k, ksz); pre##_countersetkey(&ctx, &key); } \ | |
35d66180 | 404 | \ |
57f459eb MW |
405 | static void pre##_counter_test_reset(const octet *iv) \ |
406 | { pre##_countersetiv(&ctx, iv); } \ | |
35d66180 | 407 | \ |
57f459eb MW |
408 | static void pre##_counter_test_enc(const octet *s, octet *d, size_t sz) \ |
409 | { pre##_counterencrypt(&ctx, s, d, sz); } \ | |
35d66180 | 410 | \ |
57f459eb | 411 | int main(int argc, char *argv[]) \ |
35d66180 | 412 | { \ |
57f459eb MW |
413 | return test_encmode(fname "-counter", PRE##_KEYSZ, PRE##_BLKSZ, 1, 0, \ |
414 | pre##_counter_test_setup, pre##_counter_test_reset, \ | |
415 | pre##_counter_test_enc, pre##_counter_test_enc, \ | |
416 | argc, argv); \ | |
35d66180 | 417 | } |
418 | ||
419 | #else | |
aaae9cab | 420 | # define COUNTER_TESTX(PRE, pre, name, fname) |
35d66180 | 421 | #endif |
422 | ||
423 | /*----- That's all, folks -------------------------------------------------*/ | |
424 | ||
425 | #ifdef __cplusplus | |
426 | } | |
427 | #endif | |
428 | ||
429 | #endif |