1 /* crypto/evp/bio_b64.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 #include <stdio.h>
60 #include <errno.h>
61 #include "cryptlib.h"
62 #include <openssl/buffer.h>
63 #include <openssl/evp.h>
64
65 static int b64_write(BIO *h, const char *buf, int num);
66 static int b64_read(BIO *h, char *buf, int size);
67 static int b64_puts(BIO *h, const char *str);
68 /*static int b64_gets(BIO *h, char *str, int size); */
69 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
70 static int b64_new(BIO *h);
71 static int b64_free(BIO *data);
72 static long b64_callback_ctrl(BIO *h,int cmd,bio_info_cb *fp);
73 #define B64_BLOCK_SIZE 1024
74 #define B64_BLOCK_SIZE2 768
75 #define B64_NONE 0
76 #define B64_ENCODE 1
77 #define B64_DECODE 2
78
79 typedef struct b64_struct
80 {
81 /*BIO *bio; moved to the BIO structure */
82 int buf_len;
83 int buf_off;
84 int tmp_len; /* used to find the start when decoding */
85 int tmp_nl; /* If true, scan until '\n' */
86 int encode;
87 int start; /* have we started decoding yet? */
88 int cont; /* <= 0 when finished */
89 EVP_ENCODE_CTX base64;
90 char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE)+10];
91 char tmp[B64_BLOCK_SIZE];
92 } BIO_B64_CTX;
93
94 static BIO_METHOD methods_b64=
95 {
96 BIO_TYPE_BASE64,"base64 encoding",
97 b64_write,
98 b64_read,
99 b64_puts,
100 NULL, /* b64_gets, */
101 b64_ctrl,
102 b64_new,
103 b64_free,
104 b64_callback_ctrl,
105 };
106
107 BIO_METHOD *BIO_f_base64(void)
108 {
109 return(&methods_b64);
110 }
111
112 static int b64_new(BIO *bi)
113 {
114 BIO_B64_CTX *ctx;
115
116 ctx=(BIO_B64_CTX *)OPENSSL_malloc(sizeof(BIO_B64_CTX));
117 if (ctx == NULL) return(0);
118
119 ctx->buf_len=0;
120 ctx->tmp_len=0;
121 ctx->tmp_nl=0;
122 ctx->buf_off=0;
123 ctx->cont=1;
124 ctx->start=1;
125 ctx->encode=0;
126
127 bi->init=1;
128 bi->ptr=(char *)ctx;
129 bi->flags=0;
130 bi->num = 0;
131 return(1);
132 }
133
134 static int b64_free(BIO *a)
135 {
136 if (a == NULL) return(0);
137 OPENSSL_free(a->ptr);
138 a->ptr=NULL;
139 a->init=0;
140 a->flags=0;
141 return(1);
142 }
143
144 static int b64_read(BIO *b, char *out, int outl)
145 {
146 int ret=0,i,ii,j,k,x,n,num,ret_code=0;
147 BIO_B64_CTX *ctx;
148 unsigned char *p,*q;
149
150 if (out == NULL) return(0);
151 ctx=(BIO_B64_CTX *)b->ptr;
152
153 if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
154
155 BIO_clear_retry_flags(b);
156
157 if (ctx->encode != B64_DECODE)
158 {
159 ctx->encode=B64_DECODE;
160 ctx->buf_len=0;
161 ctx->buf_off=0;
162 ctx->tmp_len=0;
163 EVP_DecodeInit(&(ctx->base64));
164 }
165
166 /* First check if there are bytes decoded/encoded */
167 if (ctx->buf_len > 0)
168 {
169 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
170 i=ctx->buf_len-ctx->buf_off;
171 if (i > outl) i=outl;
172 OPENSSL_assert(ctx->buf_off+i < (int)sizeof(ctx->buf));
173 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
174 ret=i;
175 out+=i;
176 outl-=i;
177 ctx->buf_off+=i;
178 if (ctx->buf_len == ctx->buf_off)
179 {
180 ctx->buf_len=0;
181 ctx->buf_off=0;
182 }
183 }
184
185 /* At this point, we have room of outl bytes and an empty
186 * buffer, so we should read in some more. */
187
188 ret_code=0;
189 while (outl > 0)
190 {
191 if (ctx->cont <= 0)
192 break;
193
194 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
195 B64_BLOCK_SIZE-ctx->tmp_len);
196
197 if (i <= 0)
198 {
199 ret_code=i;
200
201 /* Should we continue next time we are called? */
202 if (!BIO_should_retry(b->next_bio))
203 {
204 ctx->cont=i;
205 /* If buffer empty break */
206 if(ctx->tmp_len == 0)
207 break;
208 /* Fall through and process what we have */
209 else
210 i = 0;
211 }
212 /* else we retry and add more data to buffer */
213 else
214 break;
215 }
216 i+=ctx->tmp_len;
217 ctx->tmp_len = i;
218
219 /* We need to scan, a line at a time until we
220 * have a valid line if we are starting. */
221 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
222 {
223 /* ctx->start=1; */
224 ctx->tmp_len=0;
225 }
226 else if (ctx->start)
227 {
228 q=p=(unsigned char *)ctx->tmp;
229 num = 0;
230 for (j=0; j<i; j++)
231 {
232 if (*(q++) != '\n') continue;
233
234 /* due to a previous very long line,
235 * we need to keep on scanning for a '\n'
236 * before we even start looking for
237 * base64 encoded stuff. */
238 if (ctx->tmp_nl)
239 {
240 p=q;
241 ctx->tmp_nl=0;
242 continue;
243 }
244
245 k=EVP_DecodeUpdate(&(ctx->base64),
246 (unsigned char *)ctx->buf,
247 &num,p,q-p);
248 if ((k <= 0) && (num == 0) && (ctx->start))
249 EVP_DecodeInit(&ctx->base64);
250 else
251 {
252 if (p != (unsigned char *)
253 &(ctx->tmp[0]))
254 {
255 i-=(p- (unsigned char *)
256 &(ctx->tmp[0]));
257 for (x=0; x < i; x++)
258 ctx->tmp[x]=p[x];
259 }
260 EVP_DecodeInit(&ctx->base64);
261 ctx->start=0;
262 break;
263 }
264 p=q;
265 }
266
267 /* we fell off the end without starting */
268 if ((j == i) && (num == 0))
269 {
270 /* Is this is one long chunk?, if so, keep on
271 * reading until a new line. */
272 if (p == (unsigned char *)&(ctx->tmp[0]))
273 {
274 /* Check buffer full */
275 if (i == B64_BLOCK_SIZE)
276 {
277 ctx->tmp_nl=1;
278 ctx->tmp_len=0;
279 }
280 }
281 else if (p != q) /* finished on a '\n' */
282 {
283 n=q-p;
284 for (ii=0; ii<n; ii++)
285 ctx->tmp[ii]=p[ii];
286 ctx->tmp_len=n;
287 }
288 /* else finished on a '\n' */
289 continue;
290 }
291 else
292 {
293 ctx->tmp_len=0;
294 }
295 }
296 else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0))
297 {
298 /* If buffer isn't full and we can retry then
299 * restart to read in more data.
300 */
301 continue;
302 }
303
304 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
305 {
306 int z,jj;
307
308 #if 0
309 jj=(i>>2)<<2;
310 #else
311 jj = i & ~3; /* process per 4 */
312 #endif
313 z=EVP_DecodeBlock((unsigned char *)ctx->buf,
314 (unsigned char *)ctx->tmp,jj);
315 if (jj > 2)
316 {
317 if (ctx->tmp[jj-1] == '=')
318 {
319 z--;
320 if (ctx->tmp[jj-2] == '=')
321 z--;
322 }
323 }
324 /* z is now number of output bytes and jj is the
325 * number consumed */
326 if (jj != i)
327 {
328 memmove(ctx->tmp, &ctx->tmp[jj], i-jj);
329 ctx->tmp_len=i-jj;
330 }
331 ctx->buf_len=0;
332 if (z > 0)
333 {
334 ctx->buf_len=z;
335 }
336 i=z;
337 }
338 else
339 {
340 i=EVP_DecodeUpdate(&(ctx->base64),
341 (unsigned char *)ctx->buf,&ctx->buf_len,
342 (unsigned char *)ctx->tmp,i);
343 ctx->tmp_len = 0;
344 }
345 ctx->buf_off=0;
346 if (i < 0)
347 {
348 ret_code=0;
349 ctx->buf_len=0;
350 break;
351 }
352
353 if (ctx->buf_len <= outl)
354 i=ctx->buf_len;
355 else
356 i=outl;
357
358 memcpy(out,ctx->buf,i);
359 ret+=i;
360 ctx->buf_off=i;
361 if (ctx->buf_off == ctx->buf_len)
362 {
363 ctx->buf_len=0;
364 ctx->buf_off=0;
365 }
366 outl-=i;
367 out+=i;
368 }
369 /* BIO_clear_retry_flags(b); */
370 BIO_copy_next_retry(b);
371 return((ret == 0)?ret_code:ret);
372 }
373
374 static int b64_write(BIO *b, const char *in, int inl)
375 {
376 int ret=0;
377 int n;
378 int i;
379 BIO_B64_CTX *ctx;
380
381 ctx=(BIO_B64_CTX *)b->ptr;
382 BIO_clear_retry_flags(b);
383
384 if (ctx->encode != B64_ENCODE)
385 {
386 ctx->encode=B64_ENCODE;
387 ctx->buf_len=0;
388 ctx->buf_off=0;
389 ctx->tmp_len=0;
390 EVP_EncodeInit(&(ctx->base64));
391 }
392
393 OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
394 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
395 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
396 n=ctx->buf_len-ctx->buf_off;
397 while (n > 0)
398 {
399 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
400 if (i <= 0)
401 {
402 BIO_copy_next_retry(b);
403 return(i);
404 }
405 OPENSSL_assert(i <= n);
406 ctx->buf_off+=i;
407 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
408 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
409 n-=i;
410 }
411 /* at this point all pending data has been written */
412 ctx->buf_off=0;
413 ctx->buf_len=0;
414
415 if ((in == NULL) || (inl <= 0)) return(0);
416
417 while (inl > 0)
418 {
419 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
420
421 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
422 {
423 if (ctx->tmp_len > 0)
424 {
425 OPENSSL_assert(ctx->tmp_len <= 3);
426 n=3-ctx->tmp_len;
427 /* There's a theoretical possibility for this */
428 if (n > inl)
429 n=inl;
430 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
431 ctx->tmp_len+=n;
432 ret += n;
433 if (ctx->tmp_len < 3)
434 break;
435 ctx->buf_len=EVP_EncodeBlock((unsigned char *)ctx->buf,(unsigned char *)ctx->tmp,ctx->tmp_len);
436 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
437 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
438 /* Since we're now done using the temporary
439 buffer, the length should be 0'd */
440 ctx->tmp_len=0;
441 }
442 else
443 {
444 if (n < 3)
445 {
446 memcpy(ctx->tmp,in,n);
447 ctx->tmp_len=n;
448 ret += n;
449 break;
450 }
451 n-=n%3;
452 ctx->buf_len=EVP_EncodeBlock((unsigned char *)ctx->buf,(const unsigned char *)in,n);
453 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
454 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
455 ret += n;
456 }
457 }
458 else
459 {
460 EVP_EncodeUpdate(&(ctx->base64),
461 (unsigned char *)ctx->buf,&ctx->buf_len,
462 (unsigned char *)in,n);
463 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
464 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
465 ret += n;
466 }
467 inl-=n;
468 in+=n;
469
470 ctx->buf_off=0;
471 n=ctx->buf_len;
472 while (n > 0)
473 {
474 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
475 if (i <= 0)
476 {
477 BIO_copy_next_retry(b);
478 return((ret == 0)?i:ret);
479 }
480 OPENSSL_assert(i <= n);
481 n-=i;
482 ctx->buf_off+=i;
483 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
484 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
485 }
486 ctx->buf_len=0;
487 ctx->buf_off=0;
488 }
489 return(ret);
490 }
491
492 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
493 {
494 BIO_B64_CTX *ctx;
495 long ret=1;
496 int i;
497
498 ctx=(BIO_B64_CTX *)b->ptr;
499
500 switch (cmd)
501 {
502 case BIO_CTRL_RESET:
503 ctx->cont=1;
504 ctx->start=1;
505 ctx->encode=B64_NONE;
506 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
507 break;
508 case BIO_CTRL_EOF: /* More to read */
509 if (ctx->cont <= 0)
510 ret=1;
511 else
512 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
513 break;
514 case BIO_CTRL_WPENDING: /* More to write in buffer */
515 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
516 ret=ctx->buf_len-ctx->buf_off;
517 if ((ret == 0) && (ctx->encode != B64_NONE)
518 && (ctx->base64.num != 0))
519 ret=1;
520 else if (ret <= 0)
521 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
522 break;
523 case BIO_CTRL_PENDING: /* More to read in buffer */
524 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
525 ret=ctx->buf_len-ctx->buf_off;
526 if (ret <= 0)
527 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
528 break;
529 case BIO_CTRL_FLUSH:
530 /* do a final write */
531 again:
532 while (ctx->buf_len != ctx->buf_off)
533 {
534 i=b64_write(b,NULL,0);
535 if (i < 0)
536 return i;
537 }
538 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
539 {
540 if (ctx->tmp_len != 0)
541 {
542 ctx->buf_len=EVP_EncodeBlock(
543 (unsigned char *)ctx->buf,
544 (unsigned char *)ctx->tmp,
545 ctx->tmp_len);
546 ctx->buf_off=0;
547 ctx->tmp_len=0;
548 goto again;
549 }
550 }
551 else if (ctx->encode != B64_NONE && ctx->base64.num != 0)
552 {
553 ctx->buf_off=0;
554 EVP_EncodeFinal(&(ctx->base64),
555 (unsigned char *)ctx->buf,
556 &(ctx->buf_len));
557 /* push out the bytes */
558 goto again;
559 }
560 /* Finally flush the underlying BIO */
561 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
562 break;
563
564 case BIO_C_DO_STATE_MACHINE:
565 BIO_clear_retry_flags(b);
566 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
567 BIO_copy_next_retry(b);
568 break;
569
570 case BIO_CTRL_DUP:
571 break;
572 case BIO_CTRL_INFO:
573 case BIO_CTRL_GET:
574 case BIO_CTRL_SET:
575 default:
576 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
577 break;
578 }
579 return(ret);
580 }
581
582 static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
583 {
584 long ret=1;
585
586 if (b->next_bio == NULL) return(0);
587 switch (cmd)
588 {
589 default:
590 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
591 break;
592 }
593 return(ret);
594 }
595
596 static int b64_puts(BIO *b, const char *str)
597 {
598 return b64_write(b,str,strlen(str));
599 }