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