crypto/evp/bio_b64.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include <stdio.h>
  59 #include <errno.h>
  60 #include "internal/cryptlib.h"
  61 #include <openssl/buffer.h>
  62 #include <openssl/evp.h>
  63
  64 static int b64_write(BIO *h, const char *buf, int num);
  65 static int b64_read(BIO *h, char *buf, int size);
  66 static int b64_puts(BIO *h, const char *str);
  67 /*
  68  * static int b64_gets(BIO *h, char *str, int size);
  69  */
  70 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  71 static int b64_new(BIO *h);
  72 static int b64_free(BIO *data);
  73 static long b64_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
  74 #define B64_BLOCK_SIZE  1024
  75 #define B64_BLOCK_SIZE2 768
  76 #define B64_NONE        0
  77 #define B64_ENCODE      1
  78 #define B64_DECODE      2
  79
  80 typedef struct b64_struct {
  81     /*
  82      * BIO *bio; moved to the BIO structure
  83      */
  84     int buf_len;
  85     int buf_off;
  86     int tmp_len;                /* used to find the start when decoding */
  87     int tmp_nl;                 /* If true, scan until '\n' */
  88     int encode;
  89     int start;                  /* have we started decoding yet? */
  90     int cont;                   /* <= 0 when finished */
  91     EVP_ENCODE_CTX *base64;
  92     char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
  93     char tmp[B64_BLOCK_SIZE];
  94 } BIO_B64_CTX;
  95
  96 static BIO_METHOD methods_b64 = {
  97     BIO_TYPE_BASE64, "base64 encoding",
  98     b64_write,
  99     b64_read,
 100     b64_puts,
 101     NULL,                       /* b64_gets, */
 102     b64_ctrl,
 103     b64_new,
 104     b64_free,
 105     b64_callback_ctrl,
 106 };
 107
 108 BIO_METHOD *BIO_f_base64(void)
 109 {
 110     return (&methods_b64);
 111 }
 112
 113 static int b64_new(BIO *bi)
 114 {
 115     BIO_B64_CTX *ctx;
 116
 117     ctx = OPENSSL_zalloc(sizeof(*ctx));
 118     if (ctx == NULL)
 119         return (0);
 120
 121     ctx->cont = 1;
 122     ctx->start = 1;
 123     ctx->base64 = EVP_ENCODE_CTX_new();
 124     bi->init = 1;
 125     bi->ptr = (char *)ctx;
 126     bi->flags = 0;
 127     bi->num = 0;
 128     return (1);
 129 }
 130
 131 static int b64_free(BIO *a)
 132 {
 133     if (a == NULL)
 134         return (0);
 135     EVP_ENCODE_CTX_free(((BIO_B64_CTX *)a->ptr)->base64);
 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)
 150         return (0);
 151     ctx = (BIO_B64_CTX *)b->ptr;
 152
 153     if ((ctx == NULL) || (b->next_bio == NULL))
 154         return (0);
 155
 156     BIO_clear_retry_flags(b);
 157
 158     if (ctx->encode != B64_DECODE) {
 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         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 169         i = ctx->buf_len - ctx->buf_off;
 170         if (i > outl)
 171             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             ctx->buf_len = 0;
 180             ctx->buf_off = 0;
 181         }
 182     }
 183
 184     /*
 185      * At this point, we have room of outl bytes and an empty buffer, so we
 186      * should read in some more.
 187      */
 188
 189     ret_code = 0;
 190     while (outl > 0) {
 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             ret_code = i;
 199
 200             /* Should we continue next time we are called? */
 201             if (!BIO_should_retry(b->next_bio)) {
 202                 ctx->cont = i;
 203                 /* If buffer empty break */
 204                 if (ctx->tmp_len == 0)
 205                     break;
 206                 /* Fall through and process what we have */
 207                 else
 208                     i = 0;
 209             }
 210             /* else we retry and add more data to buffer */
 211             else
 212                 break;
 213         }
 214         i += ctx->tmp_len;
 215         ctx->tmp_len = i;
 216
 217         /*
 218          * We need to scan, a line at a time until we have a valid line if we
 219          * are starting.
 220          */
 221         if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
 222             /* ctx->start=1; */
 223             ctx->tmp_len = 0;
 224         } else if (ctx->start) {
 225             q = p = (unsigned char *)ctx->tmp;
 226             num = 0;
 227             for (j = 0; j < i; j++) {
 228                 if (*(q++) != '\n')
 229                     continue;
 230
 231                 /*
 232                  * due to a previous very long line, we need to keep on
 233                  * scanning for a '\n' before we even start looking for
 234                  * base64 encoded stuff.
 235                  */
 236                 if (ctx->tmp_nl) {
 237                     p = q;
 238                     ctx->tmp_nl = 0;
 239                     continue;
 240                 }
 241
 242                 k = EVP_DecodeUpdate(ctx->base64,
 243                                      (unsigned char *)ctx->buf,
 244                                      &num, p, q - p);
 245                 if ((k <= 0) && (num == 0) && (ctx->start))
 246                     EVP_DecodeInit(ctx->base64);
 247                 else {
 248                     if (p != (unsigned char *)
 249                         &(ctx->tmp[0])) {
 250                         i -= (p - (unsigned char *)
 251                               &(ctx->tmp[0]));
 252                         for (x = 0; x < i; x++)
 253                             ctx->tmp[x] = p[x];
 254                     }
 255                     EVP_DecodeInit(ctx->base64);
 256                     ctx->start = 0;
 257                     break;
 258                 }
 259                 p = q;
 260             }
 261
 262             /* we fell off the end without starting */
 263             if ((j == i) && (num == 0)) {
 264                 /*
 265                  * Is this is one long chunk?, if so, keep on reading until a
 266                  * new line.
 267                  */
 268                 if (p == (unsigned char *)&(ctx->tmp[0])) {
 269                     /* Check buffer full */
 270                     if (i == B64_BLOCK_SIZE) {
 271                         ctx->tmp_nl = 1;
 272                         ctx->tmp_len = 0;
 273                     }
 274                 } else if (p != q) { /* finished on a '\n' */
 275                     n = q - p;
 276                     for (ii = 0; ii < n; ii++)
 277                         ctx->tmp[ii] = p[ii];
 278                     ctx->tmp_len = n;
 279                 }
 280                 /* else finished on a '\n' */
 281                 continue;
 282             } else {
 283                 ctx->tmp_len = 0;
 284             }
 285         } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
 286             /*
 287              * If buffer isn't full and we can retry then restart to read in
 288              * more data.
 289              */
 290             continue;
 291         }
 292
 293         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
 294             int z, jj;
 295
 296             jj = i & ~3;        /* process per 4 */
 297             z = EVP_DecodeBlock((unsigned char *)ctx->buf,
 298                                 (unsigned char *)ctx->tmp, jj);
 299             if (jj > 2) {
 300                 if (ctx->tmp[jj - 1] == '=') {
 301                     z--;
 302                     if (ctx->tmp[jj - 2] == '=')
 303                         z--;
 304                 }
 305             }
 306             /*
 307              * z is now number of output bytes and jj is the number consumed
 308              */
 309             if (jj != i) {
 310                 memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
 311                 ctx->tmp_len = i - jj;
 312             }
 313             ctx->buf_len = 0;
 314             if (z > 0) {
 315                 ctx->buf_len = z;
 316             }
 317             i = z;
 318         } else {
 319             i = EVP_DecodeUpdate(ctx->base64,
 320                                  (unsigned char *)ctx->buf, &ctx->buf_len,
 321                                  (unsigned char *)ctx->tmp, i);
 322             ctx->tmp_len = 0;
 323         }
 324         ctx->buf_off = 0;
 325         if (i < 0) {
 326             ret_code = 0;
 327             ctx->buf_len = 0;
 328             break;
 329         }
 330
 331         if (ctx->buf_len <= outl)
 332             i = ctx->buf_len;
 333         else
 334             i = outl;
 335
 336         memcpy(out, ctx->buf, i);
 337         ret += i;
 338         ctx->buf_off = i;
 339         if (ctx->buf_off == ctx->buf_len) {
 340             ctx->buf_len = 0;
 341             ctx->buf_off = 0;
 342         }
 343         outl -= i;
 344         out += i;
 345     }
 346     /* BIO_clear_retry_flags(b); */
 347     BIO_copy_next_retry(b);
 348     return ((ret == 0) ? ret_code : ret);
 349 }
 350
 351 static int b64_write(BIO *b, const char *in, int inl)
 352 {
 353     int ret = 0;
 354     int n;
 355     int i;
 356     BIO_B64_CTX *ctx;
 357
 358     ctx = (BIO_B64_CTX *)b->ptr;
 359     BIO_clear_retry_flags(b);
 360
 361     if (ctx->encode != B64_ENCODE) {
 362         ctx->encode = B64_ENCODE;
 363         ctx->buf_len = 0;
 364         ctx->buf_off = 0;
 365         ctx->tmp_len = 0;
 366         EVP_EncodeInit(ctx->base64);
 367     }
 368
 369     OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
 370     OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
 371     OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 372     n = ctx->buf_len - ctx->buf_off;
 373     while (n > 0) {
 374         i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
 375         if (i <= 0) {
 376             BIO_copy_next_retry(b);
 377             return (i);
 378         }
 379         OPENSSL_assert(i <= n);
 380         ctx->buf_off += i;
 381         OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
 382         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 383         n -= i;
 384     }
 385     /* at this point all pending data has been written */
 386     ctx->buf_off = 0;
 387     ctx->buf_len = 0;
 388
 389     if ((in == NULL) || (inl <= 0))
 390         return (0);
 391
 392     while (inl > 0) {
 393         n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
 394
 395         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
 396             if (ctx->tmp_len > 0) {
 397                 OPENSSL_assert(ctx->tmp_len <= 3);
 398                 n = 3 - ctx->tmp_len;
 399                 /*
 400                  * There's a theoretical possibility for this
 401                  */
 402                 if (n > inl)
 403                     n = inl;
 404                 memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
 405                 ctx->tmp_len += n;
 406                 ret += n;
 407                 if (ctx->tmp_len < 3)
 408                     break;
 409                 ctx->buf_len =
 410                     EVP_EncodeBlock((unsigned char *)ctx->buf,
 411                                     (unsigned char *)ctx->tmp, ctx->tmp_len);
 412                 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
 413                 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 414                 /*
 415                  * Since we're now done using the temporary buffer, the
 416                  * length should be 0'd
 417                  */
 418                 ctx->tmp_len = 0;
 419             } else {
 420                 if (n < 3) {
 421                     memcpy(ctx->tmp, in, n);
 422                     ctx->tmp_len = n;
 423                     ret += n;
 424                     break;
 425                 }
 426                 n -= n % 3;
 427                 ctx->buf_len =
 428                     EVP_EncodeBlock((unsigned char *)ctx->buf,
 429                                     (const unsigned char *)in, n);
 430                 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
 431                 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 432                 ret += n;
 433             }
 434         } else {
 435             EVP_EncodeUpdate(ctx->base64,
 436                              (unsigned char *)ctx->buf, &ctx->buf_len,
 437                              (unsigned char *)in, n);
 438             OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
 439             OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 440             ret += n;
 441         }
 442         inl -= n;
 443         in += n;
 444
 445         ctx->buf_off = 0;
 446         n = ctx->buf_len;
 447         while (n > 0) {
 448             i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
 449             if (i <= 0) {
 450                 BIO_copy_next_retry(b);
 451                 return ((ret == 0) ? i : ret);
 452             }
 453             OPENSSL_assert(i <= n);
 454             n -= i;
 455             ctx->buf_off += i;
 456             OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
 457             OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 458         }
 459         ctx->buf_len = 0;
 460         ctx->buf_off = 0;
 461     }
 462     return (ret);
 463 }
 464
 465 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
 466 {
 467     BIO_B64_CTX *ctx;
 468     long ret = 1;
 469     int i;
 470
 471     ctx = (BIO_B64_CTX *)b->ptr;
 472
 473     switch (cmd) {
 474     case BIO_CTRL_RESET:
 475         ctx->cont = 1;
 476         ctx->start = 1;
 477         ctx->encode = B64_NONE;
 478         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 479         break;
 480     case BIO_CTRL_EOF:         /* More to read */
 481         if (ctx->cont <= 0)
 482             ret = 1;
 483         else
 484             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 485         break;
 486     case BIO_CTRL_WPENDING:    /* More to write in buffer */
 487         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 488         ret = ctx->buf_len - ctx->buf_off;
 489         if ((ret == 0) && (ctx->encode != B64_NONE)
 490             && (EVP_ENCODE_CTX_num(ctx->base64) != 0))
 491             ret = 1;
 492         else if (ret <= 0)
 493             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 494         break;
 495     case BIO_CTRL_PENDING:     /* More to read in buffer */
 496         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 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             i = b64_write(b, NULL, 0);
 506             if (i < 0)
 507                 return i;
 508         }
 509         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
 510             if (ctx->tmp_len != 0) {
 511                 ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
 512                                                (unsigned char *)ctx->tmp,
 513                                                ctx->tmp_len);
 514                 ctx->buf_off = 0;
 515                 ctx->tmp_len = 0;
 516                 goto again;
 517             }
 518         } else if (ctx->encode != B64_NONE
 519                    && EVP_ENCODE_CTX_num(ctx->base64) != 0) {
 520             ctx->buf_off = 0;
 521             EVP_EncodeFinal(ctx->base64,
 522                             (unsigned char *)ctx->buf, &(ctx->buf_len));
 523             /* push out the bytes */
 524             goto again;
 525         }
 526         /* Finally flush the underlying BIO */
 527         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 528         break;
 529
 530     case BIO_C_DO_STATE_MACHINE:
 531         BIO_clear_retry_flags(b);
 532         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 533         BIO_copy_next_retry(b);
 534         break;
 535
 536     case BIO_CTRL_DUP:
 537         break;
 538     case BIO_CTRL_INFO:
 539     case BIO_CTRL_GET:
 540     case BIO_CTRL_SET:
 541     default:
 542         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 543         break;
 544     }
 545     return (ret);
 546 }
 547
 548 static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 549 {
 550     long ret = 1;
 551
 552     if (b->next_bio == NULL)
 553         return (0);
 554     switch (cmd) {
 555     default:
 556         ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
 557         break;
 558     }
 559     return (ret);
 560 }
 561
 562 static int b64_puts(BIO *b, const char *str)
 563 {
 564     return b64_write(b, str, strlen(str));
 565 }