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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. | |
8 | * | |
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). | |
15 | * | |
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. | |
22 | * | |
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 :-). | |
37 | * 4. If you include any Windows specific code (or a derivative thereof) from | |
38 | * the apps directory (application code) you must include an acknowledgement: | |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
40 | * | |
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. | |
52 | * | |
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 | ||
59 | /* | |
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 | |
657e60fa | 70 | easy way to add encryption support to many existing applications |
1745a3fb BL |
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 | |
657e60fa | 83 | letting the application to read the data. |
1745a3fb BL |
84 | |
85 | BIO_f_reliable tries to solve both problems, so that you can | |
657e60fa | 86 | read and write arbitrary long streams using only fixed amount |
1745a3fb BL |
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 | ||
657e60fa | 94 | BIO_f_reliable goes further and adds several important capabilities: |
1745a3fb BL |
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 ouput | |
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 | |
657e60fa | 113 | initially wrote and tested this code on x86 machine and wrote the |
1745a3fb BL |
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. | |
117 | ||
118 | */ | |
119 | ||
120 | #include <stdio.h> | |
121 | #include <errno.h> | |
122 | #include "cryptlib.h" | |
ec577822 BM |
123 | #include <openssl/buffer.h> |
124 | #include <openssl/bio.h> | |
125 | #include <openssl/evp.h> | |
126 | #include <openssl/rand.h> | |
1745a3fb | 127 | |
1745a3fb BL |
128 | static int ok_write(BIO *h,char *buf,int num); |
129 | static int ok_read(BIO *h,char *buf,int size); | |
130 | static long ok_ctrl(BIO *h,int cmd,long arg1,char *arg2); | |
131 | static int ok_new(BIO *h); | |
132 | static int ok_free(BIO *data); | |
133 | static void sig_out(BIO* b); | |
134 | static void sig_in(BIO* b); | |
135 | static void block_out(BIO* b); | |
136 | static void block_in(BIO* b); | |
1745a3fb BL |
137 | #define OK_BLOCK_SIZE (1024*4) |
138 | #define OK_BLOCK_BLOCK 4 | |
139 | #define IOBS (OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE) | |
140 | #define WELLKNOWN "The quick brown fox jumped over the lazy dog's back." | |
141 | ||
142 | #ifndef L_ENDIAN | |
143 | #define swapem(x) \ | |
144 | ((unsigned long int)((((unsigned long int)(x) & 0x000000ffU) << 24) | \ | |
145 | (((unsigned long int)(x) & 0x0000ff00U) << 8) | \ | |
146 | (((unsigned long int)(x) & 0x00ff0000U) >> 8) | \ | |
147 | (((unsigned long int)(x) & 0xff000000U) >> 24))) | |
148 | #else | |
149 | #define swapem(x) (x) | |
150 | #endif | |
151 | ||
152 | typedef struct ok_struct | |
153 | { | |
154 | int buf_len; | |
155 | int buf_off; | |
156 | int buf_len_save; | |
157 | int buf_off_save; | |
158 | int cont; /* <= 0 when finished */ | |
159 | int finished; | |
160 | EVP_MD_CTX md; | |
161 | int blockout; /* output block is ready */ | |
162 | int sigio; /* must process signature */ | |
163 | char buf[IOBS]; | |
164 | } BIO_OK_CTX; | |
165 | ||
166 | static BIO_METHOD methods_ok= | |
167 | { | |
168 | BIO_TYPE_CIPHER,"reliable", | |
169 | ok_write, | |
170 | ok_read, | |
171 | NULL, /* ok_puts, */ | |
172 | NULL, /* ok_gets, */ | |
173 | ok_ctrl, | |
174 | ok_new, | |
175 | ok_free, | |
176 | }; | |
177 | ||
6b691a5c | 178 | BIO_METHOD *BIO_f_reliable(void) |
1745a3fb BL |
179 | { |
180 | return(&methods_ok); | |
181 | } | |
182 | ||
6b691a5c | 183 | static int ok_new(BIO *bi) |
1745a3fb BL |
184 | { |
185 | BIO_OK_CTX *ctx; | |
186 | ||
187 | ctx=(BIO_OK_CTX *)Malloc(sizeof(BIO_OK_CTX)); | |
188 | if (ctx == NULL) return(0); | |
189 | ||
190 | ctx->buf_len=0; | |
191 | ctx->buf_off=0; | |
192 | ctx->buf_len_save=0; | |
193 | ctx->buf_off_save=0; | |
194 | ctx->cont=1; | |
195 | ctx->finished=0; | |
196 | ctx->blockout= 0; | |
197 | ctx->sigio=1; | |
198 | ||
199 | bi->init=0; | |
200 | bi->ptr=(char *)ctx; | |
201 | bi->flags=0; | |
202 | return(1); | |
203 | } | |
204 | ||
6b691a5c | 205 | static int ok_free(BIO *a) |
1745a3fb BL |
206 | { |
207 | if (a == NULL) return(0); | |
208 | memset(a->ptr,0,sizeof(BIO_OK_CTX)); | |
209 | Free(a->ptr); | |
210 | a->ptr=NULL; | |
211 | a->init=0; | |
212 | a->flags=0; | |
213 | return(1); | |
214 | } | |
215 | ||
6b691a5c | 216 | static int ok_read(BIO *b, char *out, int outl) |
1745a3fb BL |
217 | { |
218 | int ret=0,i,n; | |
219 | BIO_OK_CTX *ctx; | |
220 | ||
221 | if (out == NULL) return(0); | |
222 | ctx=(BIO_OK_CTX *)b->ptr; | |
223 | ||
224 | if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0); | |
225 | ||
226 | while(outl > 0) | |
227 | { | |
228 | ||
229 | /* copy clean bytes to output buffer */ | |
230 | if (ctx->blockout) | |
231 | { | |
232 | i=ctx->buf_len-ctx->buf_off; | |
233 | if (i > outl) i=outl; | |
234 | memcpy(out,&(ctx->buf[ctx->buf_off]),i); | |
235 | ret+=i; | |
236 | out+=i; | |
237 | outl-=i; | |
238 | ctx->buf_off+=i; | |
239 | ||
240 | /* all clean bytes are out */ | |
241 | if (ctx->buf_len == ctx->buf_off) | |
242 | { | |
243 | ctx->buf_off=0; | |
244 | ||
245 | /* copy start of the next block into proper place */ | |
246 | if(ctx->buf_len_save- ctx->buf_off_save > 0) | |
247 | { | |
248 | ctx->buf_len= ctx->buf_len_save- ctx->buf_off_save; | |
249 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]), | |
250 | ctx->buf_len); | |
251 | } | |
252 | else | |
253 | { | |
254 | ctx->buf_len=0; | |
255 | } | |
256 | ctx->blockout= 0; | |
257 | } | |
258 | } | |
259 | ||
260 | /* output buffer full -- cancel */ | |
261 | if (outl == 0) break; | |
262 | ||
263 | /* no clean bytes in buffer -- fill it */ | |
264 | n=IOBS- ctx->buf_len; | |
265 | i=BIO_read(b->next_bio,&(ctx->buf[ctx->buf_len]),n); | |
266 | ||
267 | if (i <= 0) break; /* nothing new */ | |
268 | ||
269 | ctx->buf_len+= i; | |
270 | ||
271 | /* no signature yet -- check if we got one */ | |
272 | if (ctx->sigio == 1) sig_in(b); | |
273 | ||
274 | /* signature ok -- check if we got block */ | |
275 | if (ctx->sigio == 0) block_in(b); | |
276 | ||
277 | /* invalid block -- cancel */ | |
278 | if (ctx->cont <= 0) break; | |
279 | ||
280 | } | |
281 | ||
282 | BIO_clear_retry_flags(b); | |
283 | BIO_copy_next_retry(b); | |
284 | return(ret); | |
285 | } | |
286 | ||
6b691a5c | 287 | static int ok_write(BIO *b, char *in, int inl) |
1745a3fb BL |
288 | { |
289 | int ret=0,n,i; | |
290 | BIO_OK_CTX *ctx; | |
291 | ||
292 | ctx=(BIO_OK_CTX *)b->ptr; | |
293 | ret=inl; | |
294 | ||
295 | if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0); | |
296 | ||
297 | if(ctx->sigio) sig_out(b); | |
298 | ||
299 | do{ | |
300 | BIO_clear_retry_flags(b); | |
301 | n=ctx->buf_len-ctx->buf_off; | |
302 | while (ctx->blockout && n > 0) | |
303 | { | |
304 | i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n); | |
305 | if (i <= 0) | |
306 | { | |
307 | BIO_copy_next_retry(b); | |
308 | if(!BIO_should_retry(b)) | |
309 | ctx->cont= 0; | |
310 | return(i); | |
311 | } | |
312 | ctx->buf_off+=i; | |
313 | n-=i; | |
314 | } | |
315 | ||
316 | /* at this point all pending data has been written */ | |
317 | ctx->blockout= 0; | |
318 | if (ctx->buf_len == ctx->buf_off) | |
319 | { | |
320 | ctx->buf_len=OK_BLOCK_BLOCK; | |
321 | ctx->buf_off=0; | |
322 | } | |
323 | ||
324 | if ((in == NULL) || (inl <= 0)) return(0); | |
325 | ||
326 | n= (inl+ ctx->buf_len > OK_BLOCK_SIZE+ OK_BLOCK_BLOCK) ? | |
327 | OK_BLOCK_SIZE+ OK_BLOCK_BLOCK- ctx->buf_len : inl; | |
328 | ||
329 | memcpy((unsigned char *)(&(ctx->buf[ctx->buf_len])),(unsigned char *)in,n); | |
330 | ctx->buf_len+= n; | |
331 | inl-=n; | |
332 | in+=n; | |
333 | ||
334 | if(ctx->buf_len >= OK_BLOCK_SIZE+ OK_BLOCK_BLOCK) | |
335 | { | |
336 | block_out(b); | |
337 | } | |
338 | }while(inl > 0); | |
339 | ||
340 | BIO_clear_retry_flags(b); | |
341 | BIO_copy_next_retry(b); | |
342 | return(ret); | |
343 | } | |
344 | ||
6b691a5c | 345 | static long ok_ctrl(BIO *b, int cmd, long num, char *ptr) |
1745a3fb BL |
346 | { |
347 | BIO_OK_CTX *ctx; | |
348 | EVP_MD *md; | |
e778802f | 349 | const EVP_MD **ppmd; |
1745a3fb BL |
350 | long ret=1; |
351 | int i; | |
352 | ||
353 | ctx=(BIO_OK_CTX *)b->ptr; | |
354 | ||
355 | switch (cmd) | |
356 | { | |
357 | case BIO_CTRL_RESET: | |
358 | ctx->buf_len=0; | |
359 | ctx->buf_off=0; | |
360 | ctx->buf_len_save=0; | |
361 | ctx->buf_off_save=0; | |
362 | ctx->cont=1; | |
363 | ctx->finished=0; | |
364 | ctx->blockout= 0; | |
365 | ctx->sigio=1; | |
366 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
367 | break; | |
368 | case BIO_CTRL_EOF: /* More to read */ | |
369 | if (ctx->cont <= 0) | |
370 | ret=1; | |
371 | else | |
372 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
373 | break; | |
374 | case BIO_CTRL_PENDING: /* More to read in buffer */ | |
375 | case BIO_CTRL_WPENDING: /* More to read in buffer */ | |
376 | ret=ctx->blockout ? ctx->buf_len-ctx->buf_off : 0; | |
377 | if (ret <= 0) | |
378 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
379 | break; | |
380 | case BIO_CTRL_FLUSH: | |
381 | /* do a final write */ | |
382 | if(ctx->blockout == 0) | |
383 | block_out(b); | |
384 | ||
385 | while (ctx->blockout) | |
386 | { | |
387 | i=ok_write(b,NULL,0); | |
388 | if (i < 0) | |
389 | { | |
390 | ret=i; | |
391 | break; | |
392 | } | |
393 | } | |
394 | ||
395 | ctx->finished=1; | |
396 | ctx->buf_off=ctx->buf_len=0; | |
397 | ctx->cont=(int)ret; | |
398 | ||
399 | /* Finally flush the underlying BIO */ | |
400 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
401 | break; | |
402 | case BIO_C_DO_STATE_MACHINE: | |
403 | BIO_clear_retry_flags(b); | |
404 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
405 | BIO_copy_next_retry(b); | |
406 | break; | |
407 | case BIO_CTRL_INFO: | |
408 | ret=(long)ctx->cont; | |
409 | break; | |
410 | case BIO_C_SET_MD: | |
411 | md=(EVP_MD *)ptr; | |
412 | EVP_DigestInit(&(ctx->md),md); | |
413 | b->init=1; | |
414 | break; | |
415 | case BIO_C_GET_MD: | |
416 | if (b->init) | |
417 | { | |
e778802f | 418 | ppmd=(const EVP_MD **)ptr; |
1745a3fb BL |
419 | *ppmd=ctx->md.digest; |
420 | } | |
421 | else | |
422 | ret=0; | |
423 | break; | |
424 | default: | |
425 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); | |
426 | break; | |
427 | } | |
428 | return(ret); | |
429 | } | |
430 | ||
61f5b6f3 | 431 | static void longswap(void *_ptr, int len) |
1745a3fb BL |
432 | { |
433 | #ifndef L_ENDIAN | |
434 | int i; | |
61f5b6f3 | 435 | char *ptr=_ptr; |
1745a3fb BL |
436 | |
437 | for(i= 0;i < len;i+= 4){ | |
438 | *((unsigned long *)&(ptr[i]))= swapem(*((unsigned long *)&(ptr[i]))); | |
439 | } | |
440 | #endif | |
441 | } | |
442 | ||
443 | static void sig_out(BIO* b) | |
444 | { | |
445 | BIO_OK_CTX *ctx; | |
446 | EVP_MD_CTX *md; | |
447 | ||
448 | ctx=(BIO_OK_CTX *)b->ptr; | |
449 | md= &(ctx->md); | |
450 | ||
451 | if(ctx->buf_len+ 2* md->digest->md_size > OK_BLOCK_SIZE) return; | |
452 | ||
453 | EVP_DigestInit(md, md->digest); | |
e7f97e2d | 454 | RAND_pseudo_bytes(&(md->md.base[0]), md->digest->md_size); |
1745a3fb BL |
455 | memcpy(&(ctx->buf[ctx->buf_len]), &(md->md.base[0]), md->digest->md_size); |
456 | longswap(&(ctx->buf[ctx->buf_len]), md->digest->md_size); | |
457 | ctx->buf_len+= md->digest->md_size; | |
458 | ||
9d1a01be | 459 | EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)); |
1745a3fb BL |
460 | md->digest->final(&(ctx->buf[ctx->buf_len]), &(md->md.base[0])); |
461 | ctx->buf_len+= md->digest->md_size; | |
462 | ctx->blockout= 1; | |
463 | ctx->sigio= 0; | |
464 | } | |
465 | ||
466 | static void sig_in(BIO* b) | |
467 | { | |
468 | BIO_OK_CTX *ctx; | |
469 | EVP_MD_CTX *md; | |
470 | unsigned char tmp[EVP_MAX_MD_SIZE]; | |
471 | int ret= 0; | |
472 | ||
473 | ctx=(BIO_OK_CTX *)b->ptr; | |
474 | md= &(ctx->md); | |
475 | ||
476 | if(ctx->buf_len- ctx->buf_off < 2* md->digest->md_size) return; | |
477 | ||
478 | EVP_DigestInit(md, md->digest); | |
479 | memcpy(&(md->md.base[0]), &(ctx->buf[ctx->buf_off]), md->digest->md_size); | |
480 | longswap(&(md->md.base[0]), md->digest->md_size); | |
481 | ctx->buf_off+= md->digest->md_size; | |
482 | ||
9d1a01be | 483 | EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)); |
1745a3fb BL |
484 | md->digest->final(tmp, &(md->md.base[0])); |
485 | ret= memcmp(&(ctx->buf[ctx->buf_off]), tmp, md->digest->md_size) == 0; | |
486 | ctx->buf_off+= md->digest->md_size; | |
487 | if(ret == 1) | |
488 | { | |
489 | ctx->sigio= 0; | |
490 | if(ctx->buf_len != ctx->buf_off) | |
491 | { | |
492 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off]), ctx->buf_len- ctx->buf_off); | |
493 | } | |
494 | ctx->buf_len-= ctx->buf_off; | |
495 | ctx->buf_off= 0; | |
496 | } | |
497 | else | |
498 | { | |
499 | ctx->cont= 0; | |
500 | } | |
501 | } | |
502 | ||
503 | static void block_out(BIO* b) | |
504 | { | |
505 | BIO_OK_CTX *ctx; | |
506 | EVP_MD_CTX *md; | |
507 | unsigned long tl; | |
508 | ||
509 | ctx=(BIO_OK_CTX *)b->ptr; | |
510 | md= &(ctx->md); | |
511 | ||
512 | tl= ctx->buf_len- OK_BLOCK_BLOCK; | |
513 | tl= swapem(tl); | |
514 | memcpy(ctx->buf, &tl, OK_BLOCK_BLOCK); | |
515 | tl= swapem(tl); | |
95dc05bc | 516 | EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl); |
1745a3fb BL |
517 | md->digest->final(&(ctx->buf[ctx->buf_len]), &(md->md.base[0])); |
518 | ctx->buf_len+= md->digest->md_size; | |
519 | ctx->blockout= 1; | |
520 | } | |
521 | ||
522 | static void block_in(BIO* b) | |
523 | { | |
524 | BIO_OK_CTX *ctx; | |
525 | EVP_MD_CTX *md; | |
b1c4fe36 | 526 | long tl= 0; |
1745a3fb BL |
527 | unsigned char tmp[EVP_MAX_MD_SIZE]; |
528 | ||
529 | ctx=(BIO_OK_CTX *)b->ptr; | |
530 | md= &(ctx->md); | |
531 | ||
532 | memcpy(&tl, ctx->buf, OK_BLOCK_BLOCK); | |
533 | tl= swapem(tl); | |
534 | if (ctx->buf_len < tl+ OK_BLOCK_BLOCK+ md->digest->md_size) return; | |
535 | ||
95dc05bc | 536 | EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl); |
1745a3fb BL |
537 | md->digest->final(tmp, &(md->md.base[0])); |
538 | if(memcmp(&(ctx->buf[tl+ OK_BLOCK_BLOCK]), tmp, md->digest->md_size) == 0) | |
539 | { | |
540 | /* there might be parts from next block lurking around ! */ | |
541 | ctx->buf_off_save= tl+ OK_BLOCK_BLOCK+ md->digest->md_size; | |
542 | ctx->buf_len_save= ctx->buf_len; | |
543 | ctx->buf_off= OK_BLOCK_BLOCK; | |
544 | ctx->buf_len= tl+ OK_BLOCK_BLOCK; | |
545 | ctx->blockout= 1; | |
546 | } | |
547 | else | |
548 | { | |
549 | ctx->cont= 0; | |
550 | } | |
551 | } | |
552 |