bio_b64.c revision 280304
12061Sjkh/* crypto/evp/bio_b64.c */
250479Speter/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
32061Sjkh * All rights reserved.
438666Sjb *
532427Sjb * This package is an SSL implementation written
638666Sjb * by Eric Young (eay@cryptsoft.com).
738666Sjb * The implementation was written so as to conform with Netscapes SSL.
838666Sjb *
938666Sjb * This library is free for commercial and non-commercial use as long as
1038666Sjb * the following conditions are aheared to.  The following conditions
1144918Sjkh * apply to all code found in this distribution, be it the RC4, RSA,
1238666Sjb * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
1338666Sjb * included with this distribution is covered by the same copyright terms
1438666Sjb * except that the holder is Tim Hudson (tjh@cryptsoft.com).
1538666Sjb *
1638666Sjb * Copyright remains Eric Young's, and as such any Copyright notices in
1738666Sjb * the code are not to be removed.
1838666Sjb * If this package is used in a product, Eric Young should be given attribution
1938978Sjb * as the author of the parts of the library used.
2038978Sjb * This can be in the form of a textual message at program startup or
2132427Sjb * in documentation (online or textual) provided with the package.
2238666Sjb *
2338666Sjb * Redistribution and use in source and binary forms, with or without
2438666Sjb * modification, are permitted provided that the following conditions
2538666Sjb * are met:
2638666Sjb * 1. Redistributions of source code must retain the copyright
2738666Sjb *    notice, this list of conditions and the following disclaimer.
2817308Speter * 2. Redistributions in binary form must reproduce the above copyright
2938666Sjb *    notice, this list of conditions and the following disclaimer in the
3038666Sjb *    documentation and/or other materials provided with the distribution.
3138666Sjb * 3. All advertising materials mentioning features or use of this software
3219175Sbde *    must display the following acknowledgement:
3338666Sjb *    "This product includes cryptographic software written by
3438666Sjb *     Eric Young (eay@cryptsoft.com)"
3538042Sbde *    The word 'cryptographic' can be left out if the rouines from the library
3639726Sjb *    being used are not cryptographic related :-).
3738666Sjb * 4. If you include any Windows specific code (or a derivative thereof) from
3838666Sjb *    the apps directory (application code) you must include an acknowledgement:
3938042Sbde *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
4038666Sjb *
4149315Shoek * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
4217308Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
4338666Sjb * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
4438666Sjb * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
4538666Sjb * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
4638666Sjb * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
4717308Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
4845108Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
4942128Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
5042128Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
5138666Sjb * SUCH DAMAGE.
5251361Sjb *
5338666Sjb * The licence and distribution terms for any publically available version or
5417308Speter * derivative of this code cannot be changed.  i.e. this code cannot simply be
5538666Sjb * copied and put under another distribution licence
5617308Speter * [including the GNU Public Licence.]
5738666Sjb */
5817308Speter
5927910Sasami#include <stdio.h>
6043226Sjkh#include <errno.h>
6143226Sjkh#include "cryptlib.h"
6243226Sjkh#include <openssl/buffer.h>
6338666Sjb#include <openssl/evp.h>
6427910Sasami
6538666Sjbstatic int b64_write(BIO *h, const char *buf, int num);
6638666Sjbstatic int b64_read(BIO *h, char *buf, int size);
6738666Sjbstatic int b64_puts(BIO *h, const char *str);
6827910Sasami/*
6938666Sjb * static int b64_gets(BIO *h, char *str, int size);
7038666Sjb */
7143226Sjkhstatic long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
7243226Sjkhstatic int b64_new(BIO *h);
7327910Sasamistatic int b64_free(BIO *data);
7438666Sjbstatic long b64_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
7538666Sjb#define B64_BLOCK_SIZE  1024
7627910Sasami#define B64_BLOCK_SIZE2 768
7738666Sjb#define B64_NONE        0
7827910Sasami#define B64_ENCODE      1
7917308Speter#define B64_DECODE      2
8038666Sjb
8138666Sjbtypedef struct b64_struct {
8217308Speter    /*
8355678Smarcel     * BIO *bio; moved to the BIO structure
8455678Smarcel     */
8555678Smarcel    int buf_len;
8655678Smarcel    int buf_off;
872061Sjkh    int tmp_len;                /* used to find the start when decoding */
8855026Smarcel    int tmp_nl;                 /* If true, scan until '\n' */
8955026Smarcel    int encode;
9054324Smarcel    int start;                  /* have we started decoding yet? */
9117308Speter    int cont;                   /* <= 0 when finished */
9238666Sjb    EVP_ENCODE_CTX base64;
9317308Speter    char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
9455678Smarcel    char tmp[B64_BLOCK_SIZE];
9538666Sjb} BIO_B64_CTX;
9654324Smarcel
972302Spaulstatic BIO_METHOD methods_b64 = {
9839206Sjkh    BIO_TYPE_BASE64, "base64 encoding",
9939206Sjkh    b64_write,
10039206Sjkh    b64_read,
10154324Smarcel    b64_puts,
10217308Speter    NULL,                       /* b64_gets, */
10354324Smarcel    b64_ctrl,
10454324Smarcel    b64_new,
10554324Smarcel    b64_free,
10654324Smarcel    b64_callback_ctrl,
10754324Smarcel};
10854324Smarcel
10954324SmarcelBIO_METHOD *BIO_f_base64(void)
11054324Smarcel{
11154324Smarcel    return (&methods_b64);
11254324Smarcel}
11354324Smarcel
11454324Smarcelstatic int b64_new(BIO *bi)
11554324Smarcel{
11654324Smarcel    BIO_B64_CTX *ctx;
11754324Smarcel
11854324Smarcel    ctx = (BIO_B64_CTX *)OPENSSL_malloc(sizeof(BIO_B64_CTX));
11954324Smarcel    if (ctx == NULL)
12054324Smarcel        return (0);
12154324Smarcel
12254324Smarcel    ctx->buf_len = 0;
12354324Smarcel    ctx->tmp_len = 0;
12454324Smarcel    ctx->tmp_nl = 0;
12554324Smarcel    ctx->buf_off = 0;
12654324Smarcel    ctx->cont = 1;
12754324Smarcel    ctx->start = 1;
12854324Smarcel    ctx->encode = 0;
12954324Smarcel
13054324Smarcel    bi->init = 1;
13154324Smarcel    bi->ptr = (char *)ctx;
13254324Smarcel    bi->flags = 0;
13354324Smarcel    bi->num = 0;
13454324Smarcel    return (1);
13538666Sjb}
13638666Sjb
13717308Speterstatic int b64_free(BIO *a)
13838666Sjb{
13938666Sjb    if (a == NULL)
14038666Sjb        return (0);
14117308Speter    OPENSSL_free(a->ptr);
14255678Smarcel    a->ptr = NULL;
14355678Smarcel    a->init = 0;
14455678Smarcel    a->flags = 0;
14555678Smarcel    return (1);
14655678Smarcel}
1472061Sjkh
14817308Speterstatic int b64_read(BIO *b, char *out, int outl)
14938666Sjb{
15038666Sjb    int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
15117308Speter    BIO_B64_CTX *ctx;
15255678Smarcel    unsigned char *p, *q;
1533626Swollman
15417308Speter    if (out == NULL)
15555678Smarcel        return (0);
15655678Smarcel    ctx = (BIO_B64_CTX *)b->ptr;
15755678Smarcel
15855678Smarcel    if ((ctx == NULL) || (b->next_bio == NULL))
15955678Smarcel        return (0);
16055678Smarcel
16155678Smarcel    BIO_clear_retry_flags(b);
16255678Smarcel
16355678Smarcel    if (ctx->encode != B64_DECODE) {
16455678Smarcel        ctx->encode = B64_DECODE;
16555678Smarcel        ctx->buf_len = 0;
16655678Smarcel        ctx->buf_off = 0;
16755678Smarcel        ctx->tmp_len = 0;
16838666Sjb        EVP_DecodeInit(&(ctx->base64));
16938666Sjb    }
17017308Speter
17155678Smarcel    /* First check if there are bytes decoded/encoded */
17238978Sjb    if (ctx->buf_len > 0) {
1733626Swollman        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
17417308Speter        i = ctx->buf_len - ctx->buf_off;
17538666Sjb        if (i > outl)
17617308Speter            i = outl;
17743226Sjkh        OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
17843226Sjkh        memcpy(out, &(ctx->buf[ctx->buf_off]), i);
17943226Sjkh        ret = i;
18038666Sjb        out += i;
18138666Sjb        outl -= i;
18244103Smsmith        ctx->buf_off += i;
183        if (ctx->buf_len == ctx->buf_off) {
184            ctx->buf_len = 0;
185            ctx->buf_off = 0;
186        }
187    }
188
189    /*
190     * At this point, we have room of outl bytes and an empty buffer, so we
191     * should read in some more.
192     */
193
194    ret_code = 0;
195    while (outl > 0) {
196        if (ctx->cont <= 0)
197            break;
198
199        i = BIO_read(b->next_bio, &(ctx->tmp[ctx->tmp_len]),
200                     B64_BLOCK_SIZE - ctx->tmp_len);
201
202        if (i <= 0) {
203            ret_code = i;
204
205            /* Should we continue next time we are called? */
206            if (!BIO_should_retry(b->next_bio)) {
207                ctx->cont = i;
208                /* If buffer empty break */
209                if (ctx->tmp_len == 0)
210                    break;
211                /* Fall through and process what we have */
212                else
213                    i = 0;
214            }
215            /* else we retry and add more data to buffer */
216            else
217                break;
218        }
219        i += ctx->tmp_len;
220        ctx->tmp_len = i;
221
222        /*
223         * We need to scan, a line at a time until we have a valid line if we
224         * are starting.
225         */
226        if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
227            /* ctx->start=1; */
228            ctx->tmp_len = 0;
229        } else if (ctx->start) {
230            q = p = (unsigned char *)ctx->tmp;
231            num = 0;
232            for (j = 0; j < i; j++) {
233                if (*(q++) != '\n')
234                    continue;
235
236                /*
237                 * due to a previous very long line, we need to keep on
238                 * scanning for a '\n' before we even start looking for
239                 * base64 encoded stuff.
240                 */
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                /*
270                 * Is this is one long chunk?, if so, keep on reading until a
271                 * new line.
272                 */
273                if (p == (unsigned char *)&(ctx->tmp[0])) {
274                    /* Check buffer full */
275                    if (i == B64_BLOCK_SIZE) {
276                        ctx->tmp_nl = 1;
277                        ctx->tmp_len = 0;
278                    }
279                } else if (p != q) { /* finished on a '\n' */
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            /*
292             * If buffer isn't full and we can retry then restart to read in
293             * more data.
294             */
295            continue;
296        }
297
298        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
299            int z, jj;
300
301#if 0
302            jj = (i >> 2) << 2;
303#else
304            jj = i & ~3;        /* process per 4 */
305#endif
306            z = EVP_DecodeBlock((unsigned char *)ctx->buf,
307                                (unsigned char *)ctx->tmp, jj);
308            if (jj > 2) {
309                if (ctx->tmp[jj - 1] == '=') {
310                    z--;
311                    if (ctx->tmp[jj - 2] == '=')
312                        z--;
313                }
314            }
315            /*
316             * z is now number of output bytes and jj is the number consumed
317             */
318            if (jj != i) {
319                memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
320                ctx->tmp_len = i - jj;
321            }
322            ctx->buf_len = 0;
323            if (z > 0) {
324                ctx->buf_len = z;
325            }
326            i = z;
327        } else {
328            i = EVP_DecodeUpdate(&(ctx->base64),
329                                 (unsigned char *)ctx->buf, &ctx->buf_len,
330                                 (unsigned char *)ctx->tmp, i);
331            ctx->tmp_len = 0;
332        }
333        ctx->buf_off = 0;
334        if (i < 0) {
335            ret_code = 0;
336            ctx->buf_len = 0;
337            break;
338        }
339
340        if (ctx->buf_len <= outl)
341            i = ctx->buf_len;
342        else
343            i = outl;
344
345        memcpy(out, ctx->buf, i);
346        ret += i;
347        ctx->buf_off = i;
348        if (ctx->buf_off == ctx->buf_len) {
349            ctx->buf_len = 0;
350            ctx->buf_off = 0;
351        }
352        outl -= i;
353        out += i;
354    }
355    /* BIO_clear_retry_flags(b); */
356    BIO_copy_next_retry(b);
357    return ((ret == 0) ? ret_code : ret);
358}
359
360static int b64_write(BIO *b, const char *in, int inl)
361{
362    int ret = 0;
363    int n;
364    int i;
365    BIO_B64_CTX *ctx;
366
367    ctx = (BIO_B64_CTX *)b->ptr;
368    BIO_clear_retry_flags(b);
369
370    if (ctx->encode != B64_ENCODE) {
371        ctx->encode = B64_ENCODE;
372        ctx->buf_len = 0;
373        ctx->buf_off = 0;
374        ctx->tmp_len = 0;
375        EVP_EncodeInit(&(ctx->base64));
376    }
377
378    OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
379    OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
380    OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
381    n = ctx->buf_len - ctx->buf_off;
382    while (n > 0) {
383        i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
384        if (i <= 0) {
385            BIO_copy_next_retry(b);
386            return (i);
387        }
388        OPENSSL_assert(i <= n);
389        ctx->buf_off += i;
390        OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
391        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
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))
399        return (0);
400
401    while (inl > 0) {
402        n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
403
404        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
405            if (ctx->tmp_len > 0) {
406                OPENSSL_assert(ctx->tmp_len <= 3);
407                n = 3 - ctx->tmp_len;
408                /*
409                 * There's a theoretical possibility for this
410                 */
411                if (n > inl)
412                    n = inl;
413                memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
414                ctx->tmp_len += n;
415                ret += n;
416                if (ctx->tmp_len < 3)
417                    break;
418                ctx->buf_len =
419                    EVP_EncodeBlock((unsigned char *)ctx->buf,
420                                    (unsigned char *)ctx->tmp, ctx->tmp_len);
421                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
422                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
423                /*
424                 * Since we're now done using the temporary buffer, the
425                 * length should be 0'd
426                 */
427                ctx->tmp_len = 0;
428            } else {
429                if (n < 3) {
430                    memcpy(ctx->tmp, in, n);
431                    ctx->tmp_len = n;
432                    ret += n;
433                    break;
434                }
435                n -= n % 3;
436                ctx->buf_len =
437                    EVP_EncodeBlock((unsigned char *)ctx->buf,
438                                    (const unsigned char *)in, n);
439                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
440                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
441                ret += n;
442            }
443        } else {
444            EVP_EncodeUpdate(&(ctx->base64),
445                             (unsigned char *)ctx->buf, &ctx->buf_len,
446                             (unsigned char *)in, n);
447            OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
448            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
449            ret += n;
450        }
451        inl -= n;
452        in += n;
453
454        ctx->buf_off = 0;
455        n = ctx->buf_len;
456        while (n > 0) {
457            i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
458            if (i <= 0) {
459                BIO_copy_next_retry(b);
460                return ((ret == 0) ? i : ret);
461            }
462            OPENSSL_assert(i <= n);
463            n -= i;
464            ctx->buf_off += i;
465            OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
466            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
467        }
468        ctx->buf_len = 0;
469        ctx->buf_off = 0;
470    }
471    return (ret);
472}
473
474static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
475{
476    BIO_B64_CTX *ctx;
477    long ret = 1;
478    int i;
479
480    ctx = (BIO_B64_CTX *)b->ptr;
481
482    switch (cmd) {
483    case BIO_CTRL_RESET:
484        ctx->cont = 1;
485        ctx->start = 1;
486        ctx->encode = B64_NONE;
487        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
488        break;
489    case BIO_CTRL_EOF:         /* More to read */
490        if (ctx->cont <= 0)
491            ret = 1;
492        else
493            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
494        break;
495    case BIO_CTRL_WPENDING:    /* More to write in buffer */
496        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
497        ret = ctx->buf_len - ctx->buf_off;
498        if ((ret == 0) && (ctx->encode != B64_NONE)
499            && (ctx->base64.num != 0))
500            ret = 1;
501        else if (ret <= 0)
502            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
503        break;
504    case BIO_CTRL_PENDING:     /* More to read in buffer */
505        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
506        ret = ctx->buf_len - ctx->buf_off;
507        if (ret <= 0)
508            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
509        break;
510    case BIO_CTRL_FLUSH:
511        /* do a final write */
512 again:
513        while (ctx->buf_len != ctx->buf_off) {
514            i = b64_write(b, NULL, 0);
515            if (i < 0)
516                return i;
517        }
518        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
519            if (ctx->tmp_len != 0) {
520                ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
521                                               (unsigned char *)ctx->tmp,
522                                               ctx->tmp_len);
523                ctx->buf_off = 0;
524                ctx->tmp_len = 0;
525                goto again;
526            }
527        } else if (ctx->encode != B64_NONE && ctx->base64.num != 0) {
528            ctx->buf_off = 0;
529            EVP_EncodeFinal(&(ctx->base64),
530                            (unsigned char *)ctx->buf, &(ctx->buf_len));
531            /* push out the bytes */
532            goto again;
533        }
534        /* Finally flush the underlying BIO */
535        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
536        break;
537
538    case BIO_C_DO_STATE_MACHINE:
539        BIO_clear_retry_flags(b);
540        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
541        BIO_copy_next_retry(b);
542        break;
543
544    case BIO_CTRL_DUP:
545        break;
546    case BIO_CTRL_INFO:
547    case BIO_CTRL_GET:
548    case BIO_CTRL_SET:
549    default:
550        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
551        break;
552    }
553    return (ret);
554}
555
556static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
557{
558    long ret = 1;
559
560    if (b->next_bio == NULL)
561        return (0);
562    switch (cmd) {
563    default:
564        ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
565        break;
566    }
567    return (ret);
568}
569
570static int b64_puts(BIO *b, const char *str)
571{
572    return b64_write(b, str, strlen(str));
573}
574