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 /*static int b64_gets(BIO *h, char *str, int size); */
  69 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  70 static int b64_new(BIO *h);
  71 static int b64_free(BIO *data);
  72 static 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
  79 typedef 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
  94 static 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
 107 BIO_METHOD *BIO_f_base64(void)
 108         {
 109         return(&methods_b64);
 110         }
 111
 112 static 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
 134 static 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
 144 static 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
 373 static 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
 491 static 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 */
 530 again:
 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
 581 static 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
 595 static int b64_puts(BIO *b, const char *str)
 596         {
 597         return b64_write(b,str,strlen(str));
 598         }