d03ab969 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: ecb.h,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
4 | * |
5 | * Ciphertext block chaining for block ciphers |
6 | * |
7 | * (c) 1999 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: ecb.h,v $ |
33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
34 | * Initial import. |
35 | * |
36 | */ |
37 | |
38 | #ifndef ECB_H |
39 | #define ECB_H |
40 | |
41 | #ifdef __cplusplus |
42 | extern "C" { |
43 | #endif |
44 | |
45 | /*----- Header files ------------------------------------------------------*/ |
46 | |
47 | #include <assert.h> |
48 | #include <string.h> |
49 | |
50 | #include <mLib/bits.h> |
51 | |
52 | #ifndef BLKC_H |
53 | # include "blkc.h" |
54 | #endif |
55 | |
56 | /*----- Macros ------------------------------------------------------------*/ |
57 | |
58 | /* --- @ECB_DECL@ --- * |
59 | * |
60 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
61 | * |
62 | * Use: Creates declarations for ECB stealing mode. |
63 | */ |
64 | |
65 | #define ECB_DECL(PRE, pre) \ |
66 | \ |
67 | typedef struct pre ## _ecbctx { \ |
68 | pre ## _ctx ctx; /* Underlying cipher context */ \ |
69 | } pre ## _ecbctx; \ |
70 | \ |
71 | extern void pre ## _ecbsetkey(pre ## _ecbctx */*ctx*/, \ |
72 | const pre ## _ctx */*k*/); \ |
73 | \ |
74 | extern void pre ## _ecbinit(pre ## _ecbctx */*ctx*/, \ |
75 | const void */*key*/, size_t /*sz*/, \ |
76 | const void */*iv*/); \ |
77 | \ |
78 | extern void pre ## _ecbencrypt(pre ## _ecbctx */*ctx*/, \ |
79 | const void */*src*/, void */*dest*/, \ |
80 | size_t /*sz*/); \ |
81 | \ |
82 | extern void pre ## _ecbdecrypt(pre ## _ecbctx */*ctx*/, \ |
83 | const void */*src*/, void */*dest*/, \ |
84 | size_t /*sz*/); \ |
85 | |
86 | /* --- @ECB_DEF@ --- * |
87 | * |
88 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
89 | * |
90 | * Use: Creates an implementation for ECB stealing mode. |
91 | */ |
92 | |
93 | #define ECB_DEF(PRE, pre) \ |
94 | \ |
95 | /* --- @pre_ecbsetkey@ --- * \ |
96 | * \ |
97 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
98 | * @const pre_ctx *k@ = pointer to cipher context \ |
99 | * \ |
100 | * Returns: --- \ |
101 | * \ |
102 | * Use: Sets the ECB context to use a different cipher key. \ |
103 | */ \ |
104 | \ |
105 | void pre ## _ecbsetkey(pre ## _ecbctx *ctx, const pre ## _ctx *k) \ |
106 | { \ |
107 | ctx->ctx = *k; \ |
108 | } \ |
109 | \ |
110 | /* --- @pre_ecbinit@ --- * \ |
111 | * \ |
112 | * Arguments: @pre_ecbctx *ctx@ = pointer to cipher context \ |
113 | * @const void *key@ = pointer to the key buffer \ |
114 | * @size_t sz@ = size of the key \ |
115 | * @const void *iv@ = pointer to initialization vector \ |
116 | * \ |
117 | * Returns: --- \ |
118 | * \ |
119 | * Use: Initializes an ECB context ready for use. This is \ |
120 | * equivalent to calls to @pre_init@ and @pre_setkey@. \ |
121 | */ \ |
122 | \ |
123 | void pre ## _ecbinit(pre ## _ecbctx *ctx, \ |
124 | const void *key, size_t sz, \ |
125 | const void *iv) \ |
126 | { \ |
127 | pre ## _init(&ctx->ctx, key, sz); \ |
128 | } \ |
129 | \ |
130 | /* --- @pre_ecbencrypt@ --- * \ |
131 | * \ |
132 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
133 | * @const void *src@ = pointer to source data \ |
134 | * @void *dest@ = pointer to destination data \ |
135 | * @size_t sz@ = size of block to be encrypted \ |
136 | * \ |
137 | * Returns: --- \ |
138 | * \ |
139 | * Use: Encrypts a block with a block cipher in ECB mode, with \ |
140 | * ciphertext stealing and other clever tricks. \ |
141 | * Essentially, data can be encrypted in arbitrary sized \ |
142 | * chunks, although decryption must use the same chunks. \ |
143 | */ \ |
144 | \ |
145 | void pre ## _ecbencrypt(pre ## _ecbctx *ctx, \ |
146 | const void *src, void *dest, \ |
147 | size_t sz) \ |
148 | { \ |
149 | const octet *s = src; \ |
150 | octet *d = dest; \ |
151 | \ |
152 | /* --- Empty blocks are trivial --- */ \ |
153 | \ |
154 | if (!sz) \ |
155 | return; \ |
156 | \ |
157 | /* --- Short blocks aren't allowed in ECB --- * \ |
158 | * \ |
159 | * There's absolutely nothing secure I can do with them. \ |
160 | */ \ |
161 | \ |
162 | assert(((void)"ECB must have at least one whole block to work with", \ |
163 | sz >= PRE ## _BLKSZ)); \ |
164 | \ |
165 | /* --- Do the main chunk of encryption --- * \ |
166 | * \ |
167 | * This will do the whole lot if it's a whole number of blocks. Just \ |
168 | * give each block to the cipher in turn. This is trivial. \ |
169 | * Hopefully... \ |
170 | */ \ |
171 | \ |
172 | while (sz >= 2 * PRE ## _BLKSZ || sz == PRE ## _BLKSZ) { \ |
173 | uint32 x[PRE ## _BLKSZ / 4]; \ |
174 | BLKC_LOAD(PRE, x, s); \ |
175 | pre ## _eblk(&ctx->ctx, x, x); \ |
176 | BLKC_STORE(PRE, d, x); \ |
177 | s += PRE ## _BLKSZ; \ |
178 | d += PRE ## _BLKSZ; \ |
179 | sz -= PRE ## _BLKSZ; \ |
180 | } \ |
181 | \ |
182 | /* --- Do the tail-end block and bit-left-over --- * \ |
183 | * \ |
184 | * This isn't very efficient. That shouldn't matter much. \ |
185 | */ \ |
186 | \ |
187 | if (sz) { \ |
188 | uint32 x[PRE ## _BLKSZ / 4]; \ |
189 | octet b[PRE ## _BLKSZ]; \ |
190 | unsigned i; \ |
191 | \ |
192 | /* --- Let @sz@ be the size of the partial block --- */ \ |
193 | \ |
194 | sz -= PRE ## _BLKSZ; \ |
195 | \ |
196 | /* --- First stage --- * \ |
197 | * \ |
198 | * Read in the current block, and encrypt it. The first part of \ |
199 | * the result is the partial ciphertext block. Don't write that \ |
200 | * out yet, because I've not read the partial plaintext block. \ |
201 | */ \ |
202 | \ |
203 | BLKC_LOAD(PRE, x, s); \ |
204 | pre ## _eblk(&ctx->ctx, x, x); \ |
205 | BLKC_STORE(PRE, b, x); \ |
206 | \ |
207 | /* --- Second stage --- * \ |
208 | * \ |
209 | * Now move in the partial plaintext block, writing out the \ |
210 | * ciphertext as I go. Then encrypt, and write the complete \ |
211 | * ciphertext block. \ |
212 | */ \ |
213 | \ |
214 | s += PRE ## _BLKSZ; \ |
215 | d += PRE ## _BLKSZ; \ |
216 | for (i = 0; i < sz; i++) { \ |
217 | register octet y = b[i]; \ |
218 | b[i] = s[i]; \ |
219 | d[i] = y; \ |
220 | } \ |
221 | BLKC_LOAD(PRE, x, b); \ |
222 | pre ## _eblk(&ctx->ctx, x, x); \ |
223 | BLKC_STORE(PRE, d - PRE ## _BLKSZ, x); \ |
224 | } \ |
225 | \ |
226 | /* --- Done --- */ \ |
227 | \ |
228 | return; \ |
229 | } \ |
230 | \ |
231 | /* --- @pre_ecbdecrypt@ --- * \ |
232 | * \ |
233 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
234 | * @const void *src@ = pointer to source data \ |
235 | * @void *dest@ = pointer to destination data \ |
236 | * @size_t sz@ = size of block to be encrypted \ |
237 | * \ |
238 | * Returns: --- \ |
239 | * \ |
240 | * Use: Encrypts a block with a block cipher in ECB mode, with \ |
241 | * ciphertext stealing and other clever tricks. \ |
242 | * Essentially, data can be encrypted in arbitrary sized \ |
243 | * chunks, although decryption must use the same chunks. \ |
244 | */ \ |
245 | \ |
246 | void pre ## _ecbdecrypt(pre ## _ecbctx *ctx, \ |
247 | const void *src, void *dest, \ |
248 | size_t sz) \ |
249 | { \ |
250 | const octet *s = src; \ |
251 | octet *d = dest; \ |
252 | \ |
253 | /* --- Empty blocks are trivial --- */ \ |
254 | \ |
255 | if (!sz) \ |
256 | return; \ |
257 | \ |
258 | /* --- Short blocks aren't allowed in ECB --- * \ |
259 | * \ |
260 | * There's absolutely nothing secure I can do with them. \ |
261 | */ \ |
262 | \ |
263 | assert(((void)"ECB must have at least one whole block to work with", \ |
264 | sz >= PRE ## _BLKSZ)); \ |
265 | \ |
266 | /* --- Do the main chunk of decryption --- * \ |
267 | * \ |
268 | * This will do the whole lot if it's a whole number of blocks. \ |
269 | * Each block is just handed to the block cipher in turn. \ |
270 | */ \ |
271 | \ |
272 | while (sz >= 2 * PRE ## _BLKSZ || sz == PRE ## _BLKSZ) { \ |
273 | uint32 x[PRE ## _BLKSZ / 4]; \ |
274 | BLKC_LOAD(PRE, x, s); \ |
275 | pre ## _dblk(&ctx->ctx, x, x); \ |
276 | BLKC_STORE(PRE, d, x); \ |
277 | s += PRE ## _BLKSZ; \ |
278 | d += PRE ## _BLKSZ; \ |
279 | sz -= PRE ## _BLKSZ; \ |
280 | } \ |
281 | \ |
282 | /* --- Do the tail-end block and bit-left-over --- * \ |
283 | * \ |
284 | * This isn't very efficient. That shouldn't matter much. \ |
285 | */ \ |
286 | \ |
287 | if (sz) { \ |
288 | uint32 x[PRE ## _BLKSZ / 4]; \ |
289 | octet b[PRE ## _BLKSZ]; \ |
290 | unsigned i; \ |
291 | \ |
292 | /* --- Let @sz@ be the size of the partial block --- */ \ |
293 | \ |
294 | sz -= PRE ## _BLKSZ; \ |
295 | \ |
296 | /* --- First stage --- * \ |
297 | * \ |
298 | * Take the complete ciphertext block, and decrypt it. This block \ |
299 | * is carried over for the next encryption operation. \ |
300 | */ \ |
301 | \ |
302 | BLKC_LOAD(PRE, x, s); \ |
303 | pre ## _dblk(&ctx->ctx, x, x); \ |
304 | BLKC_STORE(PRE, b, x); \ |
305 | \ |
306 | /* --- Second stage --- * \ |
307 | * \ |
308 | * The first few bytes are the partial plaintext block. Write that \ |
309 | * and replace with the partial ciphertext block. Then decrypt \ |
310 | * what's left as the complete plaintext. \ |
311 | */ \ |
312 | \ |
313 | s += PRE ## _BLKSZ; \ |
314 | d += PRE ## _BLKSZ; \ |
315 | for (i = 0; i < sz; i++) { \ |
316 | register octet y = s[i]; \ |
317 | d[i] = b[i]; \ |
318 | b[i] = y; \ |
319 | } \ |
320 | BLKC_LOAD(PRE, x, b); \ |
321 | pre ## _dblk(&ctx->ctx, x, x); \ |
322 | BLKC_STORE(PRE, d - PRE ## _BLKSZ, x); \ |
323 | } \ |
324 | \ |
325 | /* --- Done --- */ \ |
326 | \ |
327 | return; \ |
328 | } \ |
329 | \ |
330 | ECB_TEST(PRE, pre) |
331 | |
332 | /*----- Test rig ----------------------------------------------------------*/ |
333 | |
334 | #ifdef TEST_RIG |
335 | |
336 | #include <stdio.h> |
337 | |
338 | #include "daftstory.h" |
339 | |
340 | /* --- @ECB_TEST@ --- * |
341 | * |
342 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions |
343 | * |
344 | * Use: Standard test rig for ECB functions. |
345 | */ |
346 | |
347 | #define ECB_TEST(PRE, pre) \ |
348 | \ |
349 | /* --- Initial plaintext for the test --- */ \ |
350 | \ |
351 | static const octet text[] = TEXT; \ |
352 | \ |
353 | /* --- Key and IV to use --- */ \ |
354 | \ |
355 | static const octet key[] = KEY; \ |
356 | static const octet iv[] = IV; \ |
357 | \ |
358 | /* --- Buffers for encryption and decryption output --- */ \ |
359 | \ |
360 | static octet ct[sizeof(text)]; \ |
361 | static octet pt[sizeof(text)]; \ |
362 | \ |
363 | static void hexdump(const octet *p, size_t sz) \ |
364 | { \ |
365 | const octet *q = p + sz; \ |
366 | for (sz = 0; p < q; p++, sz++) { \ |
367 | printf("%02x", *p); \ |
368 | if ((sz + 1) % PRE ## _BLKSZ == 0) \ |
369 | putchar(':'); \ |
370 | } \ |
371 | } \ |
372 | \ |
373 | int main(void) \ |
374 | { \ |
375 | size_t sz = 0, rest; \ |
376 | pre ## _ecbctx ctx; \ |
377 | int status = 0; \ |
378 | int done = 0; \ |
379 | \ |
380 | size_t keysz = PRE ## _KEYSZ ? \ |
381 | PRE ## _KEYSZ : strlen((const char *)key); \ |
382 | \ |
383 | fputs(#pre "-ecb: ", stdout); \ |
384 | \ |
385 | pre ## _ecbinit(&ctx, key, keysz, iv); \ |
386 | \ |
387 | while (sz <= sizeof(text)) { \ |
388 | rest = sizeof(text) - sz; \ |
389 | if ((sz != 0 && sz < PRE ## _BLKSZ) || \ |
390 | (rest != 0 && rest < PRE ## _BLKSZ)) \ |
391 | goto next; \ |
392 | memcpy(ct, text, sizeof(text)); \ |
393 | pre ## _ecbencrypt(&ctx, ct, ct, sz); \ |
394 | pre ## _ecbencrypt(&ctx, ct + sz, ct + sz, rest); \ |
395 | memcpy(pt, ct, sizeof(text)); \ |
396 | pre ## _ecbdecrypt(&ctx, pt, pt, sz); \ |
397 | pre ## _ecbdecrypt(&ctx, pt + sz, pt + sz, rest); \ |
398 | if (memcmp(pt, text, sizeof(text)) == 0) { \ |
399 | done++; \ |
400 | if (sizeof(text) < 40 || done % 8 == 0) \ |
401 | fputc('.', stdout); \ |
402 | if (done % 480 == 0) \ |
403 | fputs("\n\t", stdout); \ |
404 | fflush(stdout); \ |
405 | } else { \ |
406 | printf("\nError (sz = %lu)\n", (unsigned long)sz); \ |
407 | status = 1; \ |
408 | printf("\tplaintext = "); hexdump(text, sz); \ |
409 | printf(", "); hexdump(text + sz, rest); \ |
410 | fputc('\n', stdout); \ |
411 | printf("\tciphertext = "); hexdump(ct, sz); \ |
412 | printf(", "); hexdump(ct + sz, rest); \ |
413 | fputc('\n', stdout); \ |
414 | printf("\trecovered text = "); hexdump(pt, sz); \ |
415 | printf(", "); hexdump(pt + sz, rest); \ |
416 | fputc('\n', stdout); \ |
417 | fputc('\n', stdout); \ |
418 | } \ |
419 | next: \ |
420 | if (sz < 63) \ |
421 | sz++; \ |
422 | else \ |
423 | sz += 9; \ |
424 | } \ |
425 | \ |
426 | fputs(status ? " failed\n" : " ok\n", stdout); \ |
427 | return (status); \ |
428 | } |
429 | |
430 | #else |
431 | # define ECB_TEST(PRE, pre) |
432 | #endif |
433 | |
434 | /*----- That's all, folks -------------------------------------------------*/ |
435 | |
436 | #ifdef __cplusplus |
437 | } |
438 | #endif |
439 | |
440 | #endif |