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 /*
  69  * static int b64_gets(BIO *h, char *str, int size);
  70  */
  71 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  72 static int b64_new(BIO *h);
  73 static int b64_free(BIO *data);
  74 static long b64_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
  75 #define B64_BLOCK_SIZE  1024
  76 #define B64_BLOCK_SIZE2 768
  77 #define B64_NONE        0
  78 #define B64_ENCODE      1
  79 #define B64_DECODE      2
  80
  81 typedef struct b64_struct {
  82     /*
  83      * BIO *bio; moved to the BIO structure
  84      */
  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 BIO_METHOD methods_b64 = {
  98     BIO_TYPE_BASE64, "base64 encoding",
  99     b64_write,
 100     b64_read,
 101     b64_puts,
 102     NULL,                       /* b64_gets, */
 103     b64_ctrl,
 104     b64_new,
 105     b64_free,
 106     b64_callback_ctrl,
 107 };
 108
 109 BIO_METHOD *BIO_f_base64(void)
 110 {
 111     return (&methods_b64);
 112 }
 113
 114 static int b64_new(BIO *bi)
 115 {
 116     BIO_B64_CTX *ctx;
 117
 118     ctx = (BIO_B64_CTX *)OPENSSL_malloc(sizeof(BIO_B64_CTX));
 119     if (ctx == NULL)
 120         return (0);
 121
 122     ctx->buf_len = 0;
 123     ctx->tmp_len = 0;
 124     ctx->tmp_nl = 0;
 125     ctx->buf_off = 0;
 126     ctx->cont = 1;
 127     ctx->start = 1;
 128     ctx->encode = 0;
 129
 130     bi->init = 1;
 131     bi->ptr = (char *)ctx;
 132     bi->flags = 0;
 133     bi->num = 0;
 134     return (1);
 135 }
 136
 137 static int b64_free(BIO *a)
 138 {
 139     if (a == NULL)
 140         return (0);
 141     OPENSSL_free(a->ptr);
 142     a->ptr = NULL;
 143     a->init = 0;
 144     a->flags = 0;
 145     return (1);
 146 }
 147
 148 static int b64_read(BIO *b, char *out, int outl)
 149 {
 150     int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
 151     BIO_B64_CTX *ctx;
 152     unsigned char *p, *q;
 153
 154     if (out == NULL)
 155         return (0);
 156     ctx = (BIO_B64_CTX *)b->ptr;
 157
 158     if ((ctx == NULL) || (b->next_bio == NULL))
 159         return (0);
 160
 161     BIO_clear_retry_flags(b);
 162
 163     if (ctx->encode != B64_DECODE) {
 164         ctx->encode = B64_DECODE;
 165         ctx->buf_len = 0;
 166         ctx->buf_off = 0;
 167         ctx->tmp_len = 0;
 168         EVP_DecodeInit(&(ctx->base64));
 169     }
 170
 171     /* First check if there are bytes decoded/encoded */
 172     if (ctx->buf_len > 0) {
 173         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
 174         i = ctx->buf_len - ctx->buf_off;
 175         if (i > outl)
 176             i = outl;
 177         OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
 178         memcpy(out, &(ctx->buf[ctx->buf_off]), i);
 179         ret = i;
 180         out += i;
 181         outl -= i;
 182         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
 360 static 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
 474 static 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
 556 static 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
 570 static int b64_puts(BIO *b, const char *str)
 571 {
 572     return b64_write(b, str, strlen(str));
 573 }