1 /* $OpenBSD: bio_b64.c,v 1.29 2024/04/09 13:52:41 beck Exp $ */
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 <errno.h>
60 #include <stdio.h>
61 #include <string.h>
62
63 #include <openssl/buffer.h>
64 #include <openssl/evp.h>
65
66 #include "bio_local.h"
67 #include "evp_local.h"
68
69 static int b64_write(BIO *h, const char *buf, int num);
70 static int b64_read(BIO *h, char *buf, int size);
71 static int b64_puts(BIO *h, const char *str);
72 /*static int b64_gets(BIO *h, char *str, int size); */
73 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
74 static int b64_new(BIO *h);
75 static int b64_free(BIO *data);
76 static long b64_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
77 #define B64_BLOCK_SIZE 1024
78 #define B64_BLOCK_SIZE2 768
79 #define B64_NONE 0
80 #define B64_ENCODE 1
81 #define B64_DECODE 2
82
83 typedef struct b64_struct {
84 /*BIO *bio; moved to the BIO structure */
85 int buf_len;
86 int buf_off;
87 int tmp_len; /* used to find the start when decoding */
88 int tmp_nl; /* If true, scan until '\n' */
89 int encode;
90 int start; /* have we started decoding yet? */
91 int cont; /* <= 0 when finished */
92 EVP_ENCODE_CTX base64;
93 char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
94 char tmp[B64_BLOCK_SIZE];
95 } BIO_B64_CTX;
96
97 static const BIO_METHOD methods_b64 = {
98 .type = BIO_TYPE_BASE64,
99 .name = "base64 encoding",
100 .bwrite = b64_write,
101 .bread = b64_read,
102 .bputs = b64_puts,
103 .ctrl = b64_ctrl,
104 .create = b64_new,
105 .destroy = b64_free,
106 .callback_ctrl = b64_callback_ctrl
107 };
108
109 const BIO_METHOD *
BIO_f_base64(void)110 BIO_f_base64(void)
111 {
112 return (&methods_b64);
113 }
114 LCRYPTO_ALIAS(BIO_f_base64);
115
116 static int
b64_new(BIO * bi)117 b64_new(BIO *bi)
118 {
119 BIO_B64_CTX *ctx;
120
121 ctx = malloc(sizeof(BIO_B64_CTX));
122 if (ctx == NULL)
123 return (0);
124
125 ctx->buf_len = 0;
126 ctx->tmp_len = 0;
127 ctx->tmp_nl = 0;
128 ctx->buf_off = 0;
129 ctx->cont = 1;
130 ctx->start = 1;
131 ctx->encode = 0;
132
133 bi->init = 1;
134 bi->ptr = (char *)ctx;
135 bi->flags = 0;
136 bi->num = 0;
137 return (1);
138 }
139
140 static int
b64_free(BIO * a)141 b64_free(BIO *a)
142 {
143 if (a == NULL)
144 return (0);
145 free(a->ptr);
146 a->ptr = NULL;
147 a->init = 0;
148 a->flags = 0;
149 return (1);
150 }
151
152 static int
b64_read(BIO * b,char * out,int outl)153 b64_read(BIO *b, char *out, int outl)
154 {
155 int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
156 BIO_B64_CTX *ctx;
157 unsigned char *p, *q;
158
159 if (out == NULL)
160 return (0);
161 ctx = (BIO_B64_CTX *)b->ptr;
162
163 if ((ctx == NULL) || (b->next_bio == NULL))
164 return (0);
165
166 BIO_clear_retry_flags(b);
167
168 if (ctx->encode != B64_DECODE) {
169 ctx->encode = B64_DECODE;
170 ctx->buf_len = 0;
171 ctx->buf_off = 0;
172 ctx->tmp_len = 0;
173 EVP_DecodeInit(&(ctx->base64));
174 }
175
176 /* First check if there are bytes decoded/encoded */
177 if (ctx->buf_len > 0) {
178 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
179 i = ctx->buf_len - ctx->buf_off;
180 if (i > outl)
181 i = outl;
182 OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
183 memcpy(out, &(ctx->buf[ctx->buf_off]), i);
184 ret = i;
185 out += i;
186 outl -= i;
187 ctx->buf_off += i;
188 if (ctx->buf_len == ctx->buf_off) {
189 ctx->buf_len = 0;
190 ctx->buf_off = 0;
191 }
192 }
193
194 /* At this point, we have room of outl bytes and an empty
195 * buffer, so we should read in some more. */
196
197 ret_code = 0;
198 while (outl > 0) {
199 if (ctx->cont <= 0)
200 break;
201
202 i = BIO_read(b->next_bio, &(ctx->tmp[ctx->tmp_len]),
203 B64_BLOCK_SIZE - ctx->tmp_len);
204
205 if (i <= 0) {
206 ret_code = i;
207
208 /* Should we continue next time we are called? */
209 if (!BIO_should_retry(b->next_bio)) {
210 ctx->cont = i;
211 /* If buffer empty break */
212 if (ctx->tmp_len == 0)
213 break;
214 /* Fall through and process what we have */
215 else
216 i = 0;
217 }
218 /* else we retry and add more data to buffer */
219 else
220 break;
221 }
222 i += ctx->tmp_len;
223 ctx->tmp_len = i;
224
225 /* We need to scan, a line at a time until we
226 * have a valid line if we are starting. */
227 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
228 /* ctx->start=1; */
229 ctx->tmp_len = 0;
230 } else if (ctx->start) {
231 q = p =(unsigned char *)ctx->tmp;
232 num = 0;
233 for (j = 0; j < i; j++) {
234 if (*(q++) != '\n')
235 continue;
236
237 /* due to a previous very long line,
238 * we need to keep on scanning for a '\n'
239 * before we even start looking for
240 * base64 encoded stuff. */
241 if (ctx->tmp_nl) {
242 p = q;
243 ctx->tmp_nl = 0;
244 continue;
245 }
246
247 k = EVP_DecodeUpdate(&(ctx->base64),
248 (unsigned char *)ctx->buf,
249 &num, p, q - p);
250 if ((k <= 0) && (num == 0) && (ctx->start))
251 EVP_DecodeInit(&ctx->base64);
252 else {
253 if (p != (unsigned char *)
254 &(ctx->tmp[0])) {
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 /* 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 /* Check buffer full */
273 if (i == B64_BLOCK_SIZE) {
274 ctx->tmp_nl = 1;
275 ctx->tmp_len = 0;
276 }
277 }
278 else if (p != q) /* finished on a '\n' */
279 {
280 n = q - p;
281 for (ii = 0; ii < n; ii++)
282 ctx->tmp[ii] = p[ii];
283 ctx->tmp_len = n;
284 }
285 /* else finished on a '\n' */
286 continue;
287 } else {
288 ctx->tmp_len = 0;
289 }
290 } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
291 /* If buffer isn't full and we can retry then
292 * restart to read in more data.
293 */
294 continue;
295 }
296
297 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
298 int z, jj;
299
300 jj = i & ~3; /* process per 4 */
301 z = EVP_DecodeBlock((unsigned char *)ctx->buf,
302 (unsigned char *)ctx->tmp, jj);
303 if (jj > 2) {
304 if (ctx->tmp[jj-1] == '=') {
305 z--;
306 if (ctx->tmp[jj-2] == '=')
307 z--;
308 }
309 }
310 /* z is now number of output bytes and jj is the
311 * number consumed */
312 if (jj != i) {
313 memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
314 ctx->tmp_len = i - jj;
315 }
316 ctx->buf_len = 0;
317 if (z > 0) {
318 ctx->buf_len = z;
319 }
320 i = z;
321 } else {
322 i = EVP_DecodeUpdate(&(ctx->base64),
323 (unsigned char *)ctx->buf, &ctx->buf_len,
324 (unsigned char *)ctx->tmp, i);
325 ctx->tmp_len = 0;
326 }
327 ctx->buf_off = 0;
328 if (i < 0) {
329 ret_code = 0;
330 ctx->buf_len = 0;
331 break;
332 }
333
334 if (ctx->buf_len <= outl)
335 i = ctx->buf_len;
336 else
337 i = outl;
338
339 memcpy(out, ctx->buf, i);
340 ret += i;
341 ctx->buf_off = i;
342 if (ctx->buf_off == ctx->buf_len) {
343 ctx->buf_len = 0;
344 ctx->buf_off = 0;
345 }
346 outl -= i;
347 out += i;
348 }
349 /* BIO_clear_retry_flags(b); */
350 BIO_copy_next_retry(b);
351 return ((ret == 0) ? ret_code : ret);
352 }
353
354 static int
b64_write(BIO * b,const char * in,int inl)355 b64_write(BIO *b, const char *in, int inl)
356 {
357 int ret = 0;
358 int n;
359 int i;
360 BIO_B64_CTX *ctx;
361
362 ctx = (BIO_B64_CTX *)b->ptr;
363 BIO_clear_retry_flags(b);
364
365 if (ctx->encode != B64_ENCODE) {
366 ctx->encode = B64_ENCODE;
367 ctx->buf_len = 0;
368 ctx->buf_off = 0;
369 ctx->tmp_len = 0;
370 EVP_EncodeInit(&(ctx->base64));
371 }
372
373 OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
374 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
375 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
376 n = ctx->buf_len - ctx->buf_off;
377 while (n > 0) {
378 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
379 if (i <= 0) {
380 BIO_copy_next_retry(b);
381 return (i);
382 }
383 OPENSSL_assert(i <= n);
384 ctx->buf_off += i;
385 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
386 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
387 n -= i;
388 }
389 /* at this point all pending data has been written */
390 ctx->buf_off = 0;
391 ctx->buf_len = 0;
392
393 if ((in == NULL) || (inl <= 0))
394 return (0);
395
396 while (inl > 0) {
397 n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
398
399 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
400 if (ctx->tmp_len > 0) {
401 OPENSSL_assert(ctx->tmp_len <= 3);
402 n = 3 - ctx->tmp_len;
403 /* There's a theoretical possibility for this */
404 if (n > inl)
405 n = inl;
406 memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
407 ctx->tmp_len += n;
408 ret += n;
409 if (ctx->tmp_len < 3)
410 break;
411 ctx->buf_len = EVP_EncodeBlock(
412 (unsigned char *)ctx->buf,
413 (unsigned char *)ctx->tmp, ctx->tmp_len);
414 OPENSSL_assert(ctx->buf_len <=
415 (int)sizeof(ctx->buf));
416 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
417 /* Since we're now done using the temporary
418 buffer, the length should be 0'd */
419 ctx->tmp_len = 0;
420 } else {
421 if (n < 3) {
422 memcpy(ctx->tmp, in, n);
423 ctx->tmp_len = n;
424 ret += n;
425 break;
426 }
427 n -= n % 3;
428 ctx->buf_len = EVP_EncodeBlock(
429 (unsigned char *)ctx->buf,
430 (const unsigned char *)in, n);
431 OPENSSL_assert(ctx->buf_len <=
432 (int)sizeof(ctx->buf));
433 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
434 ret += n;
435 }
436 } else {
437 if (!EVP_EncodeUpdate(&(ctx->base64),
438 (unsigned char *)ctx->buf, &ctx->buf_len,
439 (unsigned char *)in, n))
440 return ((ret == 0) ? -1 : ret);
441 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
442 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
443 ret += n;
444 }
445 inl -= n;
446 in += n;
447
448 ctx->buf_off = 0;
449 n = ctx->buf_len;
450 while (n > 0) {
451 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
452 if (i <= 0) {
453 BIO_copy_next_retry(b);
454 return ((ret == 0) ? i : ret);
455 }
456 OPENSSL_assert(i <= n);
457 n -= i;
458 ctx->buf_off += i;
459 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
460 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
461 }
462 ctx->buf_len = 0;
463 ctx->buf_off = 0;
464 }
465 return (ret);
466 }
467
468 static long
b64_ctrl(BIO * b,int cmd,long num,void * ptr)469 b64_ctrl(BIO *b, int cmd, long num, void *ptr)
470 {
471 BIO_B64_CTX *ctx;
472 long ret = 1;
473 int i;
474
475 ctx = (BIO_B64_CTX *)b->ptr;
476
477 switch (cmd) {
478 case BIO_CTRL_RESET:
479 ctx->cont = 1;
480 ctx->start = 1;
481 ctx->encode = B64_NONE;
482 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
483 break;
484 case BIO_CTRL_EOF: /* More to read */
485 if (ctx->cont <= 0)
486 ret = 1;
487 else
488 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
489 break;
490 case BIO_CTRL_WPENDING: /* More to write in buffer */
491 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
492 ret = ctx->buf_len - ctx->buf_off;
493 if ((ret == 0) && (ctx->encode != B64_NONE) &&
494 (ctx->base64.num != 0))
495 ret = 1;
496 else if (ret <= 0)
497 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
498 break;
499 case BIO_CTRL_PENDING: /* More to read in buffer */
500 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
501 ret = ctx->buf_len - ctx->buf_off;
502 if (ret <= 0)
503 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
504 break;
505 case BIO_CTRL_FLUSH:
506 /* do a final write */
507 again:
508 while (ctx->buf_len != ctx->buf_off) {
509 i = b64_write(b, NULL, 0);
510 if (i < 0)
511 return i;
512 }
513 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
514 if (ctx->tmp_len != 0) {
515 ctx->buf_len = EVP_EncodeBlock(
516 (unsigned char *)ctx->buf,
517 (unsigned char *)ctx->tmp,
518 ctx->tmp_len);
519 ctx->buf_off = 0;
520 ctx->tmp_len = 0;
521 goto again;
522 }
523 } else if (ctx->encode != B64_NONE && ctx->base64.num != 0) {
524 ctx->buf_off = 0;
525 EVP_EncodeFinal(&(ctx->base64),
526 (unsigned char *)ctx->buf,
527 &(ctx->buf_len));
528 /* push out the bytes */
529 goto again;
530 }
531 /* Finally flush the underlying BIO */
532 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
533 break;
534
535 case BIO_C_DO_STATE_MACHINE:
536 BIO_clear_retry_flags(b);
537 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
538 BIO_copy_next_retry(b);
539 break;
540
541 case BIO_CTRL_DUP:
542 break;
543 case BIO_CTRL_INFO:
544 case BIO_CTRL_GET:
545 case BIO_CTRL_SET:
546 default:
547 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
548 break;
549 }
550 return (ret);
551 }
552
553 static long
b64_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)554 b64_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
555 {
556 long ret = 1;
557
558 if (b->next_bio == NULL)
559 return (0);
560 switch (cmd) {
561 default:
562 ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
563 break;
564 }
565 return (ret);
566 }
567
568 static int
b64_puts(BIO * b,const char * str)569 b64_puts(BIO *b, const char *str)
570 {
571 return b64_write(b, str, strlen(str));
572 }
573