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
65static int b64_write(BIO *h, const char *buf, int num);
66static int b64_read(BIO *h, char *buf, int size);
67static int b64_puts(BIO *h, const char *str);
68/*static int b64_gets(BIO *h, char *str, int size); */
69static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
70static int b64_new(BIO *h);
71static int b64_free(BIO *data);
72static 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
79typedef 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
94static 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
107BIO_METHOD *BIO_f_base64(void)
108	{
109	return(&methods_b64);
110	}
111
112static 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
134static 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
144static 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			for (j=0; j<i; j++)
230				{
231				if (*(q++) != '\n') continue;
232
233				/* due to a previous very long line,
234				 * we need to keep on scanning for a '\n'
235				 * before we even start looking for
236				 * base64 encoded stuff. */
237				if (ctx->tmp_nl)
238					{
239					p=q;
240					ctx->tmp_nl=0;
241					continue;
242					}
243
244				k=EVP_DecodeUpdate(&(ctx->base64),
245					(unsigned char *)ctx->buf,
246					&num,p,q-p);
247				if ((k <= 0) && (num == 0) && (ctx->start))
248					EVP_DecodeInit(&ctx->base64);
249				else
250					{
251					if (p != (unsigned char *)
252						&(ctx->tmp[0]))
253						{
254						i-=(p- (unsigned char *)
255							&(ctx->tmp[0]));
256						for (x=0; x < i; x++)
257							ctx->tmp[x]=p[x];
258						}
259					EVP_DecodeInit(&ctx->base64);
260					ctx->start=0;
261					break;
262					}
263				p=q;
264				}
265
266			/* we fell off the end without starting */
267			if (j == i)
268				{
269				/* Is this is one long chunk?, if so, keep on
270				 * reading until a new line. */
271				if (p == (unsigned char *)&(ctx->tmp[0]))
272					{
273					/* Check buffer full */
274					if (i == B64_BLOCK_SIZE)
275						{
276						ctx->tmp_nl=1;
277						ctx->tmp_len=0;
278						}
279					}
280				else if (p != q) /* finished on a '\n' */
281					{
282					n=q-p;
283					for (ii=0; ii<n; ii++)
284						ctx->tmp[ii]=p[ii];
285					ctx->tmp_len=n;
286					}
287				/* else finished on a '\n' */
288				continue;
289				}
290			else
291			{
292				ctx->tmp_len=0;
293			}
294		}
295		else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0))
296		{
297			/* If buffer isn't full and we can retry then
298			 * restart to read in more data.
299			 */
300			continue;
301		}
302
303		if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
304			{
305			int z,jj;
306
307#if 0
308			jj=(i>>2)<<2;
309#else
310			jj = i & ~3; /* process per 4 */
311#endif
312			z=EVP_DecodeBlock((unsigned char *)ctx->buf,
313				(unsigned char *)ctx->tmp,jj);
314			if (jj > 2)
315				{
316				if (ctx->tmp[jj-1] == '=')
317					{
318					z--;
319					if (ctx->tmp[jj-2] == '=')
320						z--;
321					}
322				}
323			/* z is now number of output bytes and jj is the
324			 * number consumed */
325			if (jj != i)
326				{
327				memmove(ctx->tmp, &ctx->tmp[jj], i-jj);
328				ctx->tmp_len=i-jj;
329				}
330			ctx->buf_len=0;
331			if (z > 0)
332				{
333				ctx->buf_len=z;
334				}
335			i=z;
336			}
337		else
338			{
339			i=EVP_DecodeUpdate(&(ctx->base64),
340				(unsigned char *)ctx->buf,&ctx->buf_len,
341				(unsigned char *)ctx->tmp,i);
342			ctx->tmp_len = 0;
343			}
344		ctx->buf_off=0;
345		if (i < 0)
346			{
347			ret_code=0;
348			ctx->buf_len=0;
349			break;
350			}
351
352		if (ctx->buf_len <= outl)
353			i=ctx->buf_len;
354		else
355			i=outl;
356
357		memcpy(out,ctx->buf,i);
358		ret+=i;
359		ctx->buf_off=i;
360		if (ctx->buf_off == ctx->buf_len)
361			{
362			ctx->buf_len=0;
363			ctx->buf_off=0;
364			}
365		outl-=i;
366		out+=i;
367		}
368	/* BIO_clear_retry_flags(b); */
369	BIO_copy_next_retry(b);
370	return((ret == 0)?ret_code:ret);
371	}
372
373static int b64_write(BIO *b, const char *in, int inl)
374	{
375	int ret=0;
376	int n;
377	int i;
378	BIO_B64_CTX *ctx;
379
380	ctx=(BIO_B64_CTX *)b->ptr;
381	BIO_clear_retry_flags(b);
382
383	if (ctx->encode != B64_ENCODE)
384		{
385		ctx->encode=B64_ENCODE;
386		ctx->buf_len=0;
387		ctx->buf_off=0;
388		ctx->tmp_len=0;
389		EVP_EncodeInit(&(ctx->base64));
390		}
391
392	OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
393	OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
394	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
395	n=ctx->buf_len-ctx->buf_off;
396	while (n > 0)
397		{
398		i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
399		if (i <= 0)
400			{
401			BIO_copy_next_retry(b);
402			return(i);
403			}
404		OPENSSL_assert(i <= n);
405		ctx->buf_off+=i;
406		OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
407		OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
408		n-=i;
409		}
410	/* at this point all pending data has been written */
411	ctx->buf_off=0;
412	ctx->buf_len=0;
413
414	if ((in == NULL) || (inl <= 0)) return(0);
415
416	while (inl > 0)
417		{
418		n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
419
420		if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
421			{
422			if (ctx->tmp_len > 0)
423				{
424				OPENSSL_assert(ctx->tmp_len <= 3);
425				n=3-ctx->tmp_len;
426				/* There's a theoretical possibility for this */
427				if (n > inl)
428					n=inl;
429				memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
430				ctx->tmp_len+=n;
431				ret += n;
432				if (ctx->tmp_len < 3)
433					break;
434				ctx->buf_len=EVP_EncodeBlock((unsigned char *)ctx->buf,(unsigned char *)ctx->tmp,ctx->tmp_len);
435				OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
436				OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
437				/* Since we're now done using the temporary
438				   buffer, the length should be 0'd */
439				ctx->tmp_len=0;
440				}
441			else
442				{
443				if (n < 3)
444					{
445					memcpy(ctx->tmp,in,n);
446					ctx->tmp_len=n;
447					ret += n;
448					break;
449					}
450				n-=n%3;
451				ctx->buf_len=EVP_EncodeBlock((unsigned char *)ctx->buf,(const unsigned char *)in,n);
452				OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
453				OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
454				ret += n;
455				}
456			}
457		else
458			{
459			EVP_EncodeUpdate(&(ctx->base64),
460				(unsigned char *)ctx->buf,&ctx->buf_len,
461				(unsigned char *)in,n);
462			OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
463			OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
464			ret += n;
465			}
466		inl-=n;
467		in+=n;
468
469		ctx->buf_off=0;
470		n=ctx->buf_len;
471		while (n > 0)
472			{
473			i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
474			if (i <= 0)
475				{
476				BIO_copy_next_retry(b);
477				return((ret == 0)?i:ret);
478				}
479			OPENSSL_assert(i <= n);
480			n-=i;
481			ctx->buf_off+=i;
482			OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
483			OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
484			}
485		ctx->buf_len=0;
486		ctx->buf_off=0;
487		}
488	return(ret);
489	}
490
491static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
492	{
493	BIO_B64_CTX *ctx;
494	long ret=1;
495	int i;
496
497	ctx=(BIO_B64_CTX *)b->ptr;
498
499	switch (cmd)
500		{
501	case BIO_CTRL_RESET:
502		ctx->cont=1;
503		ctx->start=1;
504		ctx->encode=B64_NONE;
505		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
506		break;
507	case BIO_CTRL_EOF:	/* More to read */
508		if (ctx->cont <= 0)
509			ret=1;
510		else
511			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
512		break;
513	case BIO_CTRL_WPENDING: /* More to write in buffer */
514		OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
515		ret=ctx->buf_len-ctx->buf_off;
516		if ((ret == 0) && (ctx->encode != B64_NONE)
517			&& (ctx->base64.num != 0))
518			ret=1;
519		else if (ret <= 0)
520			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
521		break;
522	case BIO_CTRL_PENDING: /* More to read in buffer */
523		OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
524		ret=ctx->buf_len-ctx->buf_off;
525		if (ret <= 0)
526			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
527		break;
528	case BIO_CTRL_FLUSH:
529		/* do a final write */
530again:
531		while (ctx->buf_len != ctx->buf_off)
532			{
533			i=b64_write(b,NULL,0);
534			if (i < 0)
535				return i;
536			}
537		if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
538			{
539			if (ctx->tmp_len != 0)
540				{
541				ctx->buf_len=EVP_EncodeBlock(
542					(unsigned char *)ctx->buf,
543					(unsigned char *)ctx->tmp,
544					ctx->tmp_len);
545				ctx->buf_off=0;
546				ctx->tmp_len=0;
547				goto again;
548				}
549			}
550		else if (ctx->encode != B64_NONE && ctx->base64.num != 0)
551			{
552			ctx->buf_off=0;
553			EVP_EncodeFinal(&(ctx->base64),
554				(unsigned char *)ctx->buf,
555				&(ctx->buf_len));
556			/* push out the bytes */
557			goto again;
558			}
559		/* Finally flush the underlying BIO */
560		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
561		break;
562
563	case BIO_C_DO_STATE_MACHINE:
564		BIO_clear_retry_flags(b);
565		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
566		BIO_copy_next_retry(b);
567		break;
568
569	case BIO_CTRL_DUP:
570		break;
571	case BIO_CTRL_INFO:
572	case BIO_CTRL_GET:
573	case BIO_CTRL_SET:
574	default:
575		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
576		break;
577		}
578	return(ret);
579	}
580
581static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
582	{
583	long ret=1;
584
585	if (b->next_bio == NULL) return(0);
586	switch (cmd)
587		{
588	default:
589		ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
590		break;
591		}
592	return(ret);
593	}
594
595static int b64_puts(BIO *b, const char *str)
596	{
597	return b64_write(b,str,strlen(str));
598	}
599