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1745a3fb BL |
1 | /* crypto/evp/bio_ok.c */ |
2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | |
3 | * All rights reserved. | |
4 | * | |
5 | * This package is an SSL implementation written | |
6 | * by Eric Young (eay@cryptsoft.com). | |
7 | * The implementation was written so as to conform with Netscapes SSL. | |
0f113f3e | 8 | * |
1745a3fb BL |
9 | * This library is free for commercial and non-commercial use as long as |
10 | * the following conditions are aheared to. The following conditions | |
11 | * apply to all code found in this distribution, be it the RC4, RSA, | |
12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
13 | * included with this distribution is covered by the same copyright terms | |
14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
0f113f3e | 15 | * |
1745a3fb BL |
16 | * Copyright remains Eric Young's, and as such any Copyright notices in |
17 | * the code are not to be removed. | |
18 | * If this package is used in a product, Eric Young should be given attribution | |
19 | * as the author of the parts of the library used. | |
20 | * This can be in the form of a textual message at program startup or | |
21 | * in documentation (online or textual) provided with the package. | |
0f113f3e | 22 | * |
1745a3fb BL |
23 | * Redistribution and use in source and binary forms, with or without |
24 | * modification, are permitted provided that the following conditions | |
25 | * are met: | |
26 | * 1. Redistributions of source code must retain the copyright | |
27 | * notice, this list of conditions and the following disclaimer. | |
28 | * 2. Redistributions in binary form must reproduce the above copyright | |
29 | * notice, this list of conditions and the following disclaimer in the | |
30 | * documentation and/or other materials provided with the distribution. | |
31 | * 3. All advertising materials mentioning features or use of this software | |
32 | * must display the following acknowledgement: | |
33 | * "This product includes cryptographic software written by | |
34 | * Eric Young (eay@cryptsoft.com)" | |
35 | * The word 'cryptographic' can be left out if the rouines from the library | |
36 | * being used are not cryptographic related :-). | |
0f113f3e | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
1745a3fb BL |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 40 | * |
1745a3fb BL |
41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
51 | * SUCH DAMAGE. | |
0f113f3e | 52 | * |
1745a3fb BL |
53 | * The licence and distribution terms for any publically available version or |
54 | * derivative of this code cannot be changed. i.e. this code cannot simply be | |
55 | * copied and put under another distribution licence | |
56 | * [including the GNU Public Licence.] | |
57 | */ | |
58 | ||
1d97c843 | 59 | /*- |
0f113f3e MC |
60 | From: Arne Ansper <arne@cyber.ee> |
61 | ||
62 | Why BIO_f_reliable? | |
63 | ||
64 | I wrote function which took BIO* as argument, read data from it | |
65 | and processed it. Then I wanted to store the input file in | |
66 | encrypted form. OK I pushed BIO_f_cipher to the BIO stack | |
67 | and everything was OK. BUT if user types wrong password | |
68 | BIO_f_cipher outputs only garbage and my function crashes. Yes | |
69 | I can and I should fix my function, but BIO_f_cipher is | |
70 | easy way to add encryption support to many existing applications | |
71 | and it's hard to debug and fix them all. | |
72 | ||
73 | So I wanted another BIO which would catch the incorrect passwords and | |
74 | file damages which cause garbage on BIO_f_cipher's output. | |
75 | ||
76 | The easy way is to push the BIO_f_md and save the checksum at | |
77 | the end of the file. However there are several problems with this | |
78 | approach: | |
79 | ||
80 | 1) you must somehow separate checksum from actual data. | |
81 | 2) you need lot's of memory when reading the file, because you | |
82 | must read to the end of the file and verify the checksum before | |
83 | letting the application to read the data. | |
84 | ||
85 | BIO_f_reliable tries to solve both problems, so that you can | |
86 | read and write arbitrary long streams using only fixed amount | |
87 | of memory. | |
88 | ||
89 | BIO_f_reliable splits data stream into blocks. Each block is prefixed | |
90 | with it's length and suffixed with it's digest. So you need only | |
91 | several Kbytes of memory to buffer single block before verifying | |
92 | it's digest. | |
93 | ||
94 | BIO_f_reliable goes further and adds several important capabilities: | |
95 | ||
96 | 1) the digest of the block is computed over the whole stream | |
97 | -- so nobody can rearrange the blocks or remove or replace them. | |
98 | ||
99 | 2) to detect invalid passwords right at the start BIO_f_reliable | |
100 | adds special prefix to the stream. In order to avoid known plain-text | |
101 | attacks this prefix is generated as follows: | |
102 | ||
103 | *) digest is initialized with random seed instead of | |
104 | standardized one. | |
105 | *) same seed is written to output | |
106 | *) well-known text is then hashed and the output | |
107 | of the digest is also written to output. | |
108 | ||
109 | reader can now read the seed from stream, hash the same string | |
110 | and then compare the digest output. | |
111 | ||
112 | Bad things: BIO_f_reliable knows what's going on in EVP_Digest. I | |
113 | initially wrote and tested this code on x86 machine and wrote the | |
114 | digests out in machine-dependent order :( There are people using | |
115 | this code and I cannot change this easily without making existing | |
116 | data files unreadable. | |
1745a3fb BL |
117 | |
118 | */ | |
119 | ||
120 | #include <stdio.h> | |
121 | #include <errno.h> | |
3205db2b | 122 | #include <assert.h> |
1745a3fb | 123 | #include "cryptlib.h" |
ec577822 BM |
124 | #include <openssl/buffer.h> |
125 | #include <openssl/bio.h> | |
126 | #include <openssl/evp.h> | |
127 | #include <openssl/rand.h> | |
1745a3fb | 128 | |
0e1c0612 UM |
129 | static int ok_write(BIO *h, const char *buf, int num); |
130 | static int ok_read(BIO *h, char *buf, int size); | |
131 | static long ok_ctrl(BIO *h, int cmd, long arg1, void *arg2); | |
1745a3fb BL |
132 | static int ok_new(BIO *h); |
133 | static int ok_free(BIO *data); | |
13083215 | 134 | static long ok_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp); |
d3442bc7 | 135 | |
0f113f3e MC |
136 | static __owur int sig_out(BIO *b); |
137 | static __owur int sig_in(BIO *b); | |
138 | static __owur int block_out(BIO *b); | |
139 | static __owur int block_in(BIO *b); | |
140 | #define OK_BLOCK_SIZE (1024*4) | |
141 | #define OK_BLOCK_BLOCK 4 | |
142 | #define IOBS (OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE) | |
1745a3fb BL |
143 | #define WELLKNOWN "The quick brown fox jumped over the lazy dog's back." |
144 | ||
0f113f3e MC |
145 | typedef struct ok_struct { |
146 | size_t buf_len; | |
147 | size_t buf_off; | |
148 | size_t buf_len_save; | |
149 | size_t buf_off_save; | |
150 | int cont; /* <= 0 when finished */ | |
151 | int finished; | |
152 | EVP_MD_CTX md; | |
153 | int blockout; /* output block is ready */ | |
154 | int sigio; /* must process signature */ | |
155 | unsigned char buf[IOBS]; | |
156 | } BIO_OK_CTX; | |
157 | ||
158 | static BIO_METHOD methods_ok = { | |
159 | BIO_TYPE_CIPHER, "reliable", | |
160 | ok_write, | |
161 | ok_read, | |
162 | NULL, /* ok_puts, */ | |
163 | NULL, /* ok_gets, */ | |
164 | ok_ctrl, | |
165 | ok_new, | |
166 | ok_free, | |
167 | ok_callback_ctrl, | |
168 | }; | |
1745a3fb | 169 | |
6b691a5c | 170 | BIO_METHOD *BIO_f_reliable(void) |
0f113f3e MC |
171 | { |
172 | return (&methods_ok); | |
173 | } | |
1745a3fb | 174 | |
6b691a5c | 175 | static int ok_new(BIO *bi) |
0f113f3e MC |
176 | { |
177 | BIO_OK_CTX *ctx; | |
178 | ||
179 | ctx = (BIO_OK_CTX *)OPENSSL_malloc(sizeof(BIO_OK_CTX)); | |
180 | if (ctx == NULL) | |
181 | return (0); | |
182 | ||
183 | ctx->buf_len = 0; | |
184 | ctx->buf_off = 0; | |
185 | ctx->buf_len_save = 0; | |
186 | ctx->buf_off_save = 0; | |
187 | ctx->cont = 1; | |
188 | ctx->finished = 0; | |
189 | ctx->blockout = 0; | |
190 | ctx->sigio = 1; | |
191 | ||
192 | EVP_MD_CTX_init(&ctx->md); | |
193 | ||
194 | bi->init = 0; | |
195 | bi->ptr = (char *)ctx; | |
196 | bi->flags = 0; | |
197 | return (1); | |
198 | } | |
1745a3fb | 199 | |
6b691a5c | 200 | static int ok_free(BIO *a) |
0f113f3e MC |
201 | { |
202 | if (a == NULL) | |
203 | return (0); | |
204 | EVP_MD_CTX_cleanup(&((BIO_OK_CTX *)a->ptr)->md); | |
205 | OPENSSL_cleanse(a->ptr, sizeof(BIO_OK_CTX)); | |
206 | OPENSSL_free(a->ptr); | |
207 | a->ptr = NULL; | |
208 | a->init = 0; | |
209 | a->flags = 0; | |
210 | return (1); | |
211 | } | |
212 | ||
6b691a5c | 213 | static int ok_read(BIO *b, char *out, int outl) |
0f113f3e MC |
214 | { |
215 | int ret = 0, i, n; | |
216 | BIO_OK_CTX *ctx; | |
217 | ||
218 | if (out == NULL) | |
219 | return (0); | |
220 | ctx = (BIO_OK_CTX *)b->ptr; | |
221 | ||
222 | if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) | |
223 | return (0); | |
224 | ||
225 | while (outl > 0) { | |
226 | ||
227 | /* copy clean bytes to output buffer */ | |
228 | if (ctx->blockout) { | |
229 | i = ctx->buf_len - ctx->buf_off; | |
230 | if (i > outl) | |
231 | i = outl; | |
232 | memcpy(out, &(ctx->buf[ctx->buf_off]), i); | |
233 | ret += i; | |
234 | out += i; | |
235 | outl -= i; | |
236 | ctx->buf_off += i; | |
237 | ||
238 | /* all clean bytes are out */ | |
239 | if (ctx->buf_len == ctx->buf_off) { | |
240 | ctx->buf_off = 0; | |
241 | ||
242 | /* | |
243 | * copy start of the next block into proper place | |
244 | */ | |
245 | if (ctx->buf_len_save - ctx->buf_off_save > 0) { | |
246 | ctx->buf_len = ctx->buf_len_save - ctx->buf_off_save; | |
247 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]), | |
248 | ctx->buf_len); | |
249 | } else { | |
250 | ctx->buf_len = 0; | |
251 | } | |
252 | ctx->blockout = 0; | |
253 | } | |
254 | } | |
255 | ||
256 | /* output buffer full -- cancel */ | |
257 | if (outl == 0) | |
258 | break; | |
259 | ||
260 | /* no clean bytes in buffer -- fill it */ | |
261 | n = IOBS - ctx->buf_len; | |
262 | i = BIO_read(b->next_bio, &(ctx->buf[ctx->buf_len]), n); | |
263 | ||
264 | if (i <= 0) | |
265 | break; /* nothing new */ | |
266 | ||
267 | ctx->buf_len += i; | |
268 | ||
269 | /* no signature yet -- check if we got one */ | |
270 | if (ctx->sigio == 1) { | |
271 | if (!sig_in(b)) { | |
272 | BIO_clear_retry_flags(b); | |
273 | return 0; | |
274 | } | |
275 | } | |
276 | ||
277 | /* signature ok -- check if we got block */ | |
278 | if (ctx->sigio == 0) { | |
279 | if (!block_in(b)) { | |
280 | BIO_clear_retry_flags(b); | |
281 | return 0; | |
282 | } | |
283 | } | |
284 | ||
285 | /* invalid block -- cancel */ | |
286 | if (ctx->cont <= 0) | |
287 | break; | |
288 | ||
289 | } | |
290 | ||
291 | BIO_clear_retry_flags(b); | |
292 | BIO_copy_next_retry(b); | |
293 | return (ret); | |
294 | } | |
1745a3fb | 295 | |
0e1c0612 | 296 | static int ok_write(BIO *b, const char *in, int inl) |
0f113f3e MC |
297 | { |
298 | int ret = 0, n, i; | |
299 | BIO_OK_CTX *ctx; | |
300 | ||
301 | if (inl <= 0) | |
302 | return inl; | |
303 | ||
304 | ctx = (BIO_OK_CTX *)b->ptr; | |
305 | ret = inl; | |
306 | ||
307 | if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) | |
308 | return (0); | |
309 | ||
310 | if (ctx->sigio && !sig_out(b)) | |
311 | return 0; | |
312 | ||
313 | do { | |
314 | BIO_clear_retry_flags(b); | |
315 | n = ctx->buf_len - ctx->buf_off; | |
316 | while (ctx->blockout && n > 0) { | |
317 | i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n); | |
318 | if (i <= 0) { | |
319 | BIO_copy_next_retry(b); | |
320 | if (!BIO_should_retry(b)) | |
321 | ctx->cont = 0; | |
322 | return (i); | |
323 | } | |
324 | ctx->buf_off += i; | |
325 | n -= i; | |
326 | } | |
327 | ||
328 | /* at this point all pending data has been written */ | |
329 | ctx->blockout = 0; | |
330 | if (ctx->buf_len == ctx->buf_off) { | |
331 | ctx->buf_len = OK_BLOCK_BLOCK; | |
332 | ctx->buf_off = 0; | |
333 | } | |
334 | ||
335 | if ((in == NULL) || (inl <= 0)) | |
336 | return (0); | |
337 | ||
338 | n = (inl + ctx->buf_len > OK_BLOCK_SIZE + OK_BLOCK_BLOCK) ? | |
339 | (int)(OK_BLOCK_SIZE + OK_BLOCK_BLOCK - ctx->buf_len) : inl; | |
340 | ||
341 | memcpy((unsigned char *)(&(ctx->buf[ctx->buf_len])), | |
342 | (unsigned char *)in, n); | |
343 | ctx->buf_len += n; | |
344 | inl -= n; | |
345 | in += n; | |
346 | ||
347 | if (ctx->buf_len >= OK_BLOCK_SIZE + OK_BLOCK_BLOCK) { | |
348 | if (!block_out(b)) { | |
349 | BIO_clear_retry_flags(b); | |
350 | return 0; | |
351 | } | |
352 | } | |
353 | } while (inl > 0); | |
354 | ||
355 | BIO_clear_retry_flags(b); | |
356 | BIO_copy_next_retry(b); | |
357 | return (ret); | |
358 | } | |
1745a3fb | 359 | |
0e1c0612 | 360 | static long ok_ctrl(BIO *b, int cmd, long num, void *ptr) |
0f113f3e MC |
361 | { |
362 | BIO_OK_CTX *ctx; | |
363 | EVP_MD *md; | |
364 | const EVP_MD **ppmd; | |
365 | long ret = 1; | |
366 | int i; | |
367 | ||
368 | ctx = b->ptr; | |
369 | ||
370 | switch (cmd) { | |
371 | case BIO_CTRL_RESET: | |
372 | ctx->buf_len = 0; | |
373 | ctx->buf_off = 0; | |
374 | ctx->buf_len_save = 0; | |
375 | ctx->buf_off_save = 0; | |
376 | ctx->cont = 1; | |
377 | ctx->finished = 0; | |
378 | ctx->blockout = 0; | |
379 | ctx->sigio = 1; | |
380 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
381 | break; | |
382 | case BIO_CTRL_EOF: /* More to read */ | |
383 | if (ctx->cont <= 0) | |
384 | ret = 1; | |
385 | else | |
386 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
387 | break; | |
388 | case BIO_CTRL_PENDING: /* More to read in buffer */ | |
389 | case BIO_CTRL_WPENDING: /* More to read in buffer */ | |
390 | ret = ctx->blockout ? ctx->buf_len - ctx->buf_off : 0; | |
391 | if (ret <= 0) | |
392 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
393 | break; | |
394 | case BIO_CTRL_FLUSH: | |
395 | /* do a final write */ | |
396 | if (ctx->blockout == 0) | |
397 | if (!block_out(b)) | |
398 | return 0; | |
399 | ||
400 | while (ctx->blockout) { | |
401 | i = ok_write(b, NULL, 0); | |
402 | if (i < 0) { | |
403 | ret = i; | |
404 | break; | |
405 | } | |
406 | } | |
407 | ||
408 | ctx->finished = 1; | |
409 | ctx->buf_off = ctx->buf_len = 0; | |
410 | ctx->cont = (int)ret; | |
411 | ||
412 | /* Finally flush the underlying BIO */ | |
413 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
414 | break; | |
415 | case BIO_C_DO_STATE_MACHINE: | |
416 | BIO_clear_retry_flags(b); | |
417 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
418 | BIO_copy_next_retry(b); | |
419 | break; | |
420 | case BIO_CTRL_INFO: | |
421 | ret = (long)ctx->cont; | |
422 | break; | |
423 | case BIO_C_SET_MD: | |
424 | md = ptr; | |
425 | if (!EVP_DigestInit_ex(&ctx->md, md, NULL)) | |
426 | return 0; | |
427 | b->init = 1; | |
428 | break; | |
429 | case BIO_C_GET_MD: | |
430 | if (b->init) { | |
431 | ppmd = ptr; | |
432 | *ppmd = ctx->md.digest; | |
433 | } else | |
434 | ret = 0; | |
435 | break; | |
436 | default: | |
437 | ret = BIO_ctrl(b->next_bio, cmd, num, ptr); | |
438 | break; | |
439 | } | |
440 | return (ret); | |
441 | } | |
1745a3fb | 442 | |
13083215 | 443 | static long ok_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp) |
0f113f3e MC |
444 | { |
445 | long ret = 1; | |
446 | ||
447 | if (b->next_bio == NULL) | |
448 | return (0); | |
449 | switch (cmd) { | |
450 | default: | |
451 | ret = BIO_callback_ctrl(b->next_bio, cmd, fp); | |
452 | break; | |
453 | } | |
454 | return (ret); | |
455 | } | |
d3442bc7 | 456 | |
3205db2b | 457 | static void longswap(void *_ptr, size_t len) |
0f113f3e MC |
458 | { |
459 | const union { | |
460 | long one; | |
461 | char little; | |
462 | } is_endian = { | |
463 | 1 | |
464 | }; | |
465 | ||
466 | if (is_endian.little) { | |
467 | size_t i; | |
468 | unsigned char *p = _ptr, c; | |
469 | ||
470 | for (i = 0; i < len; i += 4) { | |
471 | c = p[0], p[0] = p[3], p[3] = c; | |
472 | c = p[1], p[1] = p[2], p[2] = c; | |
473 | } | |
474 | } | |
475 | } | |
3205db2b | 476 | |
0f113f3e MC |
477 | static int sig_out(BIO *b) |
478 | { | |
479 | BIO_OK_CTX *ctx; | |
480 | EVP_MD_CTX *md; | |
481 | ||
482 | ctx = b->ptr; | |
483 | md = &ctx->md; | |
484 | ||
485 | if (ctx->buf_len + 2 * md->digest->md_size > OK_BLOCK_SIZE) | |
486 | return 1; | |
487 | ||
488 | if (!EVP_DigestInit_ex(md, md->digest, NULL)) | |
489 | goto berr; | |
490 | /* | |
491 | * FIXME: there's absolutely no guarantee this makes any sense at all, | |
492 | * particularly now EVP_MD_CTX has been restructured. | |
493 | */ | |
494 | RAND_pseudo_bytes(md->md_data, md->digest->md_size); | |
495 | memcpy(&(ctx->buf[ctx->buf_len]), md->md_data, md->digest->md_size); | |
496 | longswap(&(ctx->buf[ctx->buf_len]), md->digest->md_size); | |
497 | ctx->buf_len += md->digest->md_size; | |
498 | ||
499 | if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN))) | |
500 | goto berr; | |
501 | if (!EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL)) | |
502 | goto berr; | |
503 | ctx->buf_len += md->digest->md_size; | |
504 | ctx->blockout = 1; | |
505 | ctx->sigio = 0; | |
506 | return 1; | |
507 | berr: | |
508 | BIO_clear_retry_flags(b); | |
509 | return 0; | |
510 | } | |
1745a3fb | 511 | |
0f113f3e MC |
512 | static int sig_in(BIO *b) |
513 | { | |
514 | BIO_OK_CTX *ctx; | |
515 | EVP_MD_CTX *md; | |
516 | unsigned char tmp[EVP_MAX_MD_SIZE]; | |
517 | int ret = 0; | |
518 | ||
519 | ctx = b->ptr; | |
520 | md = &ctx->md; | |
521 | ||
522 | if ((int)(ctx->buf_len - ctx->buf_off) < 2 * md->digest->md_size) | |
523 | return 1; | |
524 | ||
525 | if (!EVP_DigestInit_ex(md, md->digest, NULL)) | |
526 | goto berr; | |
527 | memcpy(md->md_data, &(ctx->buf[ctx->buf_off]), md->digest->md_size); | |
528 | longswap(md->md_data, md->digest->md_size); | |
529 | ctx->buf_off += md->digest->md_size; | |
530 | ||
531 | if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN))) | |
532 | goto berr; | |
533 | if (!EVP_DigestFinal_ex(md, tmp, NULL)) | |
534 | goto berr; | |
535 | ret = memcmp(&(ctx->buf[ctx->buf_off]), tmp, md->digest->md_size) == 0; | |
536 | ctx->buf_off += md->digest->md_size; | |
537 | if (ret == 1) { | |
538 | ctx->sigio = 0; | |
539 | if (ctx->buf_len != ctx->buf_off) { | |
540 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off]), | |
541 | ctx->buf_len - ctx->buf_off); | |
542 | } | |
543 | ctx->buf_len -= ctx->buf_off; | |
544 | ctx->buf_off = 0; | |
545 | } else { | |
546 | ctx->cont = 0; | |
547 | } | |
548 | return 1; | |
549 | berr: | |
550 | BIO_clear_retry_flags(b); | |
551 | return 0; | |
1745a3fb BL |
552 | } |
553 | ||
0f113f3e MC |
554 | static int block_out(BIO *b) |
555 | { | |
556 | BIO_OK_CTX *ctx; | |
557 | EVP_MD_CTX *md; | |
558 | unsigned long tl; | |
559 | ||
560 | ctx = b->ptr; | |
561 | md = &ctx->md; | |
562 | ||
563 | tl = ctx->buf_len - OK_BLOCK_BLOCK; | |
564 | ctx->buf[0] = (unsigned char)(tl >> 24); | |
565 | ctx->buf[1] = (unsigned char)(tl >> 16); | |
566 | ctx->buf[2] = (unsigned char)(tl >> 8); | |
567 | ctx->buf[3] = (unsigned char)(tl); | |
568 | if (!EVP_DigestUpdate(md, | |
569 | (unsigned char *)&(ctx->buf[OK_BLOCK_BLOCK]), tl)) | |
570 | goto berr; | |
571 | if (!EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL)) | |
572 | goto berr; | |
573 | ctx->buf_len += md->digest->md_size; | |
574 | ctx->blockout = 1; | |
575 | return 1; | |
576 | berr: | |
577 | BIO_clear_retry_flags(b); | |
578 | return 0; | |
579 | } | |
1745a3fb | 580 | |
0f113f3e MC |
581 | static int block_in(BIO *b) |
582 | { | |
583 | BIO_OK_CTX *ctx; | |
584 | EVP_MD_CTX *md; | |
585 | unsigned long tl = 0; | |
586 | unsigned char tmp[EVP_MAX_MD_SIZE]; | |
587 | ||
588 | ctx = b->ptr; | |
589 | md = &ctx->md; | |
590 | ||
591 | assert(sizeof(tl) >= OK_BLOCK_BLOCK); /* always true */ | |
592 | tl = ctx->buf[0]; | |
593 | tl <<= 8; | |
594 | tl |= ctx->buf[1]; | |
595 | tl <<= 8; | |
596 | tl |= ctx->buf[2]; | |
597 | tl <<= 8; | |
598 | tl |= ctx->buf[3]; | |
599 | ||
600 | if (ctx->buf_len < tl + OK_BLOCK_BLOCK + md->digest->md_size) | |
601 | return 1; | |
602 | ||
603 | if (!EVP_DigestUpdate(md, | |
604 | (unsigned char *)&(ctx->buf[OK_BLOCK_BLOCK]), tl)) | |
605 | goto berr; | |
606 | if (!EVP_DigestFinal_ex(md, tmp, NULL)) | |
607 | goto berr; | |
608 | if (memcmp(&(ctx->buf[tl + OK_BLOCK_BLOCK]), tmp, md->digest->md_size) == | |
609 | 0) { | |
610 | /* there might be parts from next block lurking around ! */ | |
611 | ctx->buf_off_save = tl + OK_BLOCK_BLOCK + md->digest->md_size; | |
612 | ctx->buf_len_save = ctx->buf_len; | |
613 | ctx->buf_off = OK_BLOCK_BLOCK; | |
614 | ctx->buf_len = tl + OK_BLOCK_BLOCK; | |
615 | ctx->blockout = 1; | |
616 | } else { | |
617 | ctx->cont = 0; | |
618 | } | |
619 | return 1; | |
620 | berr: | |
621 | BIO_clear_retry_flags(b); | |
622 | return 0; | |
623 | } |