summaryrefslogtreecommitdiff
path: root/src/lib/libcrypto/evp/bio_ok.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libcrypto/evp/bio_ok.c')
-rw-r--r--src/lib/libcrypto/evp/bio_ok.c575
1 files changed, 575 insertions, 0 deletions
diff --git a/src/lib/libcrypto/evp/bio_ok.c b/src/lib/libcrypto/evp/bio_ok.c
new file mode 100644
index 0000000000..4e3f10141b
--- /dev/null
+++ b/src/lib/libcrypto/evp/bio_ok.c
@@ -0,0 +1,575 @@
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
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.
117
118*/
119
120#include <stdio.h>
121#include <errno.h>
122#include "cryptlib.h"
123#include <openssl/buffer.h>
124#include <openssl/bio.h>
125#include <openssl/evp.h>
126#include <openssl/rand.h>
127
128static int ok_write(BIO *h, const char *buf, int num);
129static int ok_read(BIO *h, char *buf, int size);
130static long ok_ctrl(BIO *h, int cmd, long arg1, void *arg2);
131static int ok_new(BIO *h);
132static int ok_free(BIO *data);
133static long ok_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
134
135static void sig_out(BIO* b);
136static void sig_in(BIO* b);
137static void block_out(BIO* b);
138static void block_in(BIO* b);
139#define OK_BLOCK_SIZE (1024*4)
140#define OK_BLOCK_BLOCK 4
141#define IOBS (OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE)
142#define WELLKNOWN "The quick brown fox jumped over the lazy dog's back."
143
144#ifndef L_ENDIAN
145#define swapem(x) \
146 ((unsigned long int)((((unsigned long int)(x) & 0x000000ffU) << 24) | \
147 (((unsigned long int)(x) & 0x0000ff00U) << 8) | \
148 (((unsigned long int)(x) & 0x00ff0000U) >> 8) | \
149 (((unsigned long int)(x) & 0xff000000U) >> 24)))
150#else
151#define swapem(x) (x)
152#endif
153
154typedef struct ok_struct
155 {
156 int buf_len;
157 int buf_off;
158 int buf_len_save;
159 int buf_off_save;
160 int cont; /* <= 0 when finished */
161 int finished;
162 EVP_MD_CTX md;
163 int blockout; /* output block is ready */
164 int sigio; /* must process signature */
165 unsigned char buf[IOBS];
166 } BIO_OK_CTX;
167
168static BIO_METHOD methods_ok=
169 {
170 BIO_TYPE_CIPHER,"reliable",
171 ok_write,
172 ok_read,
173 NULL, /* ok_puts, */
174 NULL, /* ok_gets, */
175 ok_ctrl,
176 ok_new,
177 ok_free,
178 ok_callback_ctrl,
179 };
180
181BIO_METHOD *BIO_f_reliable(void)
182 {
183 return(&methods_ok);
184 }
185
186static int ok_new(BIO *bi)
187 {
188 BIO_OK_CTX *ctx;
189
190 ctx=(BIO_OK_CTX *)OPENSSL_malloc(sizeof(BIO_OK_CTX));
191 if (ctx == NULL) return(0);
192
193 ctx->buf_len=0;
194 ctx->buf_off=0;
195 ctx->buf_len_save=0;
196 ctx->buf_off_save=0;
197 ctx->cont=1;
198 ctx->finished=0;
199 ctx->blockout= 0;
200 ctx->sigio=1;
201
202 EVP_MD_CTX_init(&ctx->md);
203
204 bi->init=0;
205 bi->ptr=(char *)ctx;
206 bi->flags=0;
207 return(1);
208 }
209
210static int ok_free(BIO *a)
211 {
212 if (a == NULL) return(0);
213 EVP_MD_CTX_cleanup(&((BIO_OK_CTX *)a->ptr)->md);
214 OPENSSL_cleanse(a->ptr,sizeof(BIO_OK_CTX));
215 OPENSSL_free(a->ptr);
216 a->ptr=NULL;
217 a->init=0;
218 a->flags=0;
219 return(1);
220 }
221
222static int ok_read(BIO *b, char *out, int outl)
223 {
224 int ret=0,i,n;
225 BIO_OK_CTX *ctx;
226
227 if (out == NULL) return(0);
228 ctx=(BIO_OK_CTX *)b->ptr;
229
230 if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
231
232 while(outl > 0)
233 {
234
235 /* copy clean bytes to output buffer */
236 if (ctx->blockout)
237 {
238 i=ctx->buf_len-ctx->buf_off;
239 if (i > outl) i=outl;
240 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
241 ret+=i;
242 out+=i;
243 outl-=i;
244 ctx->buf_off+=i;
245
246 /* all clean bytes are out */
247 if (ctx->buf_len == ctx->buf_off)
248 {
249 ctx->buf_off=0;
250
251 /* copy start of the next block into proper place */
252 if(ctx->buf_len_save- ctx->buf_off_save > 0)
253 {
254 ctx->buf_len= ctx->buf_len_save- ctx->buf_off_save;
255 memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]),
256 ctx->buf_len);
257 }
258 else
259 {
260 ctx->buf_len=0;
261 }
262 ctx->blockout= 0;
263 }
264 }
265
266 /* output buffer full -- cancel */
267 if (outl == 0) break;
268
269 /* no clean bytes in buffer -- fill it */
270 n=IOBS- ctx->buf_len;
271 i=BIO_read(b->next_bio,&(ctx->buf[ctx->buf_len]),n);
272
273 if (i <= 0) break; /* nothing new */
274
275 ctx->buf_len+= i;
276
277 /* no signature yet -- check if we got one */
278 if (ctx->sigio == 1) sig_in(b);
279
280 /* signature ok -- check if we got block */
281 if (ctx->sigio == 0) block_in(b);
282
283 /* invalid block -- cancel */
284 if (ctx->cont <= 0) break;
285
286 }
287
288 BIO_clear_retry_flags(b);
289 BIO_copy_next_retry(b);
290 return(ret);
291 }
292
293static int ok_write(BIO *b, const char *in, int inl)
294 {
295 int ret=0,n,i;
296 BIO_OK_CTX *ctx;
297
298 ctx=(BIO_OK_CTX *)b->ptr;
299 ret=inl;
300
301 if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
302
303 if(ctx->sigio) sig_out(b);
304
305 do{
306 BIO_clear_retry_flags(b);
307 n=ctx->buf_len-ctx->buf_off;
308 while (ctx->blockout && n > 0)
309 {
310 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
311 if (i <= 0)
312 {
313 BIO_copy_next_retry(b);
314 if(!BIO_should_retry(b))
315 ctx->cont= 0;
316 return(i);
317 }
318 ctx->buf_off+=i;
319 n-=i;
320 }
321
322 /* at this point all pending data has been written */
323 ctx->blockout= 0;
324 if (ctx->buf_len == ctx->buf_off)
325 {
326 ctx->buf_len=OK_BLOCK_BLOCK;
327 ctx->buf_off=0;
328 }
329
330 if ((in == NULL) || (inl <= 0)) return(0);
331
332 n= (inl+ ctx->buf_len > OK_BLOCK_SIZE+ OK_BLOCK_BLOCK) ?
333 OK_BLOCK_SIZE+ OK_BLOCK_BLOCK- ctx->buf_len : inl;
334
335 memcpy((unsigned char *)(&(ctx->buf[ctx->buf_len])),(unsigned char *)in,n);
336 ctx->buf_len+= n;
337 inl-=n;
338 in+=n;
339
340 if(ctx->buf_len >= OK_BLOCK_SIZE+ OK_BLOCK_BLOCK)
341 {
342 block_out(b);
343 }
344 }while(inl > 0);
345
346 BIO_clear_retry_flags(b);
347 BIO_copy_next_retry(b);
348 return(ret);
349 }
350
351static long ok_ctrl(BIO *b, int cmd, long num, void *ptr)
352 {
353 BIO_OK_CTX *ctx;
354 EVP_MD *md;
355 const EVP_MD **ppmd;
356 long ret=1;
357 int i;
358
359 ctx=b->ptr;
360
361 switch (cmd)
362 {
363 case BIO_CTRL_RESET:
364 ctx->buf_len=0;
365 ctx->buf_off=0;
366 ctx->buf_len_save=0;
367 ctx->buf_off_save=0;
368 ctx->cont=1;
369 ctx->finished=0;
370 ctx->blockout= 0;
371 ctx->sigio=1;
372 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
373 break;
374 case BIO_CTRL_EOF: /* More to read */
375 if (ctx->cont <= 0)
376 ret=1;
377 else
378 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
379 break;
380 case BIO_CTRL_PENDING: /* More to read in buffer */
381 case BIO_CTRL_WPENDING: /* More to read in buffer */
382 ret=ctx->blockout ? ctx->buf_len-ctx->buf_off : 0;
383 if (ret <= 0)
384 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
385 break;
386 case BIO_CTRL_FLUSH:
387 /* do a final write */
388 if(ctx->blockout == 0)
389 block_out(b);
390
391 while (ctx->blockout)
392 {
393 i=ok_write(b,NULL,0);
394 if (i < 0)
395 {
396 ret=i;
397 break;
398 }
399 }
400
401 ctx->finished=1;
402 ctx->buf_off=ctx->buf_len=0;
403 ctx->cont=(int)ret;
404
405 /* Finally flush the underlying BIO */
406 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
407 break;
408 case BIO_C_DO_STATE_MACHINE:
409 BIO_clear_retry_flags(b);
410 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
411 BIO_copy_next_retry(b);
412 break;
413 case BIO_CTRL_INFO:
414 ret=(long)ctx->cont;
415 break;
416 case BIO_C_SET_MD:
417 md=ptr;
418 EVP_DigestInit_ex(&ctx->md, md, NULL);
419 b->init=1;
420 break;
421 case BIO_C_GET_MD:
422 if (b->init)
423 {
424 ppmd=ptr;
425 *ppmd=ctx->md.digest;
426 }
427 else
428 ret=0;
429 break;
430 default:
431 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
432 break;
433 }
434 return(ret);
435 }
436
437static long ok_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
438 {
439 long ret=1;
440
441 if (b->next_bio == NULL) return(0);
442 switch (cmd)
443 {
444 default:
445 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
446 break;
447 }
448 return(ret);
449 }
450
451static void longswap(void *_ptr, int len)
452{
453#ifndef L_ENDIAN
454 int i;
455 char *ptr=_ptr;
456
457 for(i= 0;i < len;i+= 4){
458 *((unsigned long *)&(ptr[i]))= swapem(*((unsigned long *)&(ptr[i])));
459 }
460#endif
461}
462
463static void sig_out(BIO* b)
464 {
465 BIO_OK_CTX *ctx;
466 EVP_MD_CTX *md;
467
468 ctx=b->ptr;
469 md=&ctx->md;
470
471 if(ctx->buf_len+ 2* md->digest->md_size > OK_BLOCK_SIZE) return;
472
473 EVP_DigestInit_ex(md, md->digest, NULL);
474 /* FIXME: there's absolutely no guarantee this makes any sense at all,
475 * particularly now EVP_MD_CTX has been restructured.
476 */
477 RAND_pseudo_bytes(md->md_data, md->digest->md_size);
478 memcpy(&(ctx->buf[ctx->buf_len]), md->md_data, md->digest->md_size);
479 longswap(&(ctx->buf[ctx->buf_len]), md->digest->md_size);
480 ctx->buf_len+= md->digest->md_size;
481
482 EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
483 EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL);
484 ctx->buf_len+= md->digest->md_size;
485 ctx->blockout= 1;
486 ctx->sigio= 0;
487 }
488
489static void sig_in(BIO* b)
490 {
491 BIO_OK_CTX *ctx;
492 EVP_MD_CTX *md;
493 unsigned char tmp[EVP_MAX_MD_SIZE];
494 int ret= 0;
495
496 ctx=b->ptr;
497 md=&ctx->md;
498
499 if(ctx->buf_len- ctx->buf_off < 2* md->digest->md_size) return;
500
501 EVP_DigestInit_ex(md, md->digest, NULL);
502 memcpy(md->md_data, &(ctx->buf[ctx->buf_off]), md->digest->md_size);
503 longswap(md->md_data, md->digest->md_size);
504 ctx->buf_off+= md->digest->md_size;
505
506 EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
507 EVP_DigestFinal_ex(md, tmp, NULL);
508 ret= memcmp(&(ctx->buf[ctx->buf_off]), tmp, md->digest->md_size) == 0;
509 ctx->buf_off+= md->digest->md_size;
510 if(ret == 1)
511 {
512 ctx->sigio= 0;
513 if(ctx->buf_len != ctx->buf_off)
514 {
515 memmove(ctx->buf, &(ctx->buf[ctx->buf_off]), ctx->buf_len- ctx->buf_off);
516 }
517 ctx->buf_len-= ctx->buf_off;
518 ctx->buf_off= 0;
519 }
520 else
521 {
522 ctx->cont= 0;
523 }
524 }
525
526static void block_out(BIO* b)
527 {
528 BIO_OK_CTX *ctx;
529 EVP_MD_CTX *md;
530 unsigned long tl;
531
532 ctx=b->ptr;
533 md=&ctx->md;
534
535 tl= ctx->buf_len- OK_BLOCK_BLOCK;
536 tl= swapem(tl);
537 memcpy(ctx->buf, &tl, OK_BLOCK_BLOCK);
538 tl= swapem(tl);
539 EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl);
540 EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL);
541 ctx->buf_len+= md->digest->md_size;
542 ctx->blockout= 1;
543 }
544
545static void block_in(BIO* b)
546 {
547 BIO_OK_CTX *ctx;
548 EVP_MD_CTX *md;
549 long tl= 0;
550 unsigned char tmp[EVP_MAX_MD_SIZE];
551
552 ctx=b->ptr;
553 md=&ctx->md;
554
555 memcpy(&tl, ctx->buf, OK_BLOCK_BLOCK);
556 tl= swapem(tl);
557 if (ctx->buf_len < tl+ OK_BLOCK_BLOCK+ md->digest->md_size) return;
558
559 EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl);
560 EVP_DigestFinal_ex(md, tmp, NULL);
561 if(memcmp(&(ctx->buf[tl+ OK_BLOCK_BLOCK]), tmp, md->digest->md_size) == 0)
562 {
563 /* there might be parts from next block lurking around ! */
564 ctx->buf_off_save= tl+ OK_BLOCK_BLOCK+ md->digest->md_size;
565 ctx->buf_len_save= ctx->buf_len;
566 ctx->buf_off= OK_BLOCK_BLOCK;
567 ctx->buf_len= tl+ OK_BLOCK_BLOCK;
568 ctx->blockout= 1;
569 }
570 else
571 {
572 ctx->cont= 0;
573 }
574 }
575