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         NULL, /* 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         return(1);
 131         }
 132
 133 static int b64_free(BIO *a)
 134         {
 135         if (a == NULL) return(0);
 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) return(0);
 150         ctx=(BIO_B64_CTX *)b->ptr;
 151
 152         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 153
 154         if (ctx->encode != B64_DECODE)
 155                 {
 156                 ctx->encode=B64_DECODE;
 157                 ctx->buf_len=0;
 158                 ctx->buf_off=0;
 159                 ctx->tmp_len=0;
 160                 EVP_DecodeInit(&(ctx->base64));
 161                 }
 162
 163         /* First check if there are bytes decoded/encoded */
 164         if (ctx->buf_len > 0)
 165                 {
 166                 i=ctx->buf_len-ctx->buf_off;
 167                 if (i > outl) i=outl;
 168                 OPENSSL_assert(ctx->buf_off+i < (int)sizeof(ctx->buf));
 169                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 170                 ret=i;
 171                 out+=i;
 172                 outl-=i;
 173                 ctx->buf_off+=i;
 174                 if (ctx->buf_len == ctx->buf_off)
 175                         {
 176                         ctx->buf_len=0;
 177                         ctx->buf_off=0;
 178                         }
 179                 }
 180
 181         /* At this point, we have room of outl bytes and an empty
 182          * buffer, so we should read in some more. */
 183
 184         ret_code=0;
 185         while (outl > 0)
 186                 {
 187
 188                 if (ctx->cont <= 0)
 189                         break;
 190
 191                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 192                         B64_BLOCK_SIZE-ctx->tmp_len);
 193
 194                 if (i <= 0)
 195                         {
 196                         ret_code=i;
 197
 198                         /* Should be continue next time we are called? */
 199                         if (!BIO_should_retry(b->next_bio))
 200                                 {
 201                                 ctx->cont=i;
 202                                 /* If buffer empty break */
 203                                 if(ctx->tmp_len == 0)
 204                                         break;
 205                                 /* Fall through and process what we have */
 206                                 else
 207                                         i = 0;
 208                                 }
 209                         /* else we retry and add more data to buffer */
 210                         else
 211                                 break;
 212                         }
 213                 i+=ctx->tmp_len;
 214                 ctx->tmp_len = i;
 215
 216                 /* We need to scan, a line at a time until we
 217                  * have a valid line if we are starting. */
 218                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 219                         {
 220                         /* ctx->start=1; */
 221                         ctx->tmp_len=0;
 222                         }
 223                 else if (ctx->start)
 224                         {
 225                         q=p=(unsigned char *)ctx->tmp;
 226                         for (j=0; j<i; j++)
 227                                 {
 228                                 if (*(q++) != '\n') continue;
 229
 230                                 /* due to a previous very long line,
 231                                  * we need to keep on scanning for a '\n'
 232                                  * before we even start looking for
 233                                  * base64 encoded stuff. */
 234                                 if (ctx->tmp_nl)
 235                                         {
 236                                         p=q;
 237                                         ctx->tmp_nl=0;
 238                                         continue;
 239                                         }
 240
 241                                 k=EVP_DecodeUpdate(&(ctx->base64),
 242                                         (unsigned char *)ctx->buf,
 243                                         &num,p,q-p);
 244                                 if ((k <= 0) && (num == 0) && (ctx->start))
 245                                         EVP_DecodeInit(&ctx->base64);
 246                                 else
 247                                         {
 248                                         if (p != (unsigned char *)
 249                                                 &(ctx->tmp[0]))
 250                                                 {
 251                                                 i-=(p- (unsigned char *)
 252                                                         &(ctx->tmp[0]));
 253                                                 for (x=0; x < i; x++)
 254                                                         ctx->tmp[x]=p[x];
 255                                                 }
 256                                         EVP_DecodeInit(&ctx->base64);
 257                                         ctx->start=0;
 258                                         break;
 259                                         }
 260                                 p=q;
 261                                 }
 262
 263                         /* we fell off the end without starting */
 264                         if (j == i)
 265                                 {
 266                                 /* Is this is one long chunk?, if so, keep on
 267                                  * reading until a new line. */
 268                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 269                                         {
 270                                         /* Check buffer full */
 271                                         if (i == B64_BLOCK_SIZE)
 272                                                 {
 273                                                 ctx->tmp_nl=1;
 274                                                 ctx->tmp_len=0;
 275                                                 }
 276                                         }
 277                                 else if (p != q) /* finished on a '\n' */
 278                                         {
 279                                         n=q-p;
 280                                         for (ii=0; ii<n; ii++)
 281                                                 ctx->tmp[ii]=p[ii];
 282                                         ctx->tmp_len=n;
 283                                         }
 284                                 /* else finished on a '\n' */
 285                                 continue;
 286                                 }
 287                         else
 288                                 ctx->tmp_len=0;
 289                         }
 290                 /* If buffer isn't full and we can retry then
 291                  * restart to read in more data.
 292                  */
 293                 else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0))
 294                         continue;
 295
 296                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 297                         {
 298                         int z,jj;
 299
 300                         jj=(i>>2)<<2;
 301                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 302                                 (unsigned char *)ctx->tmp,jj);
 303                         if (jj > 2)
 304                                 {
 305                                 if (ctx->tmp[jj-1] == '=')
 306                                         {
 307                                         z--;
 308                                         if (ctx->tmp[jj-2] == '=')
 309                                                 z--;
 310                                         }
 311                                 }
 312                         /* z is now number of output bytes and jj is the
 313                          * number consumed */
 314                         if (jj != i)
 315                                 {
 316                                 memcpy((unsigned char *)ctx->tmp,
 317                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 318                                 ctx->tmp_len=i-jj;
 319                                 }
 320                         ctx->buf_len=0;
 321                         if (z > 0)
 322                                 {
 323                                 ctx->buf_len=z;
 324                                 i=1;
 325                                 }
 326                         else
 327                                 i=z;
 328                         }
 329                 else
 330                         {
 331                         i=EVP_DecodeUpdate(&(ctx->base64),
 332                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 333                                 (unsigned char *)ctx->tmp,i);
 334                         ctx->tmp_len = 0;
 335                         }
 336                 ctx->buf_off=0;
 337                 if (i < 0)
 338                         {
 339                         ret_code=0;
 340                         ctx->buf_len=0;
 341                         break;
 342                         }
 343
 344                 if (ctx->buf_len <= outl)
 345                         i=ctx->buf_len;
 346                 else
 347                         i=outl;
 348
 349                 memcpy(out,ctx->buf,i);
 350                 ret+=i;
 351                 ctx->buf_off=i;
 352                 if (ctx->buf_off == ctx->buf_len)
 353                         {
 354                         ctx->buf_len=0;
 355                         ctx->buf_off=0;
 356                         }
 357                 outl-=i;
 358                 out+=i;
 359                 }
 360         BIO_clear_retry_flags(b);
 361         BIO_copy_next_retry(b);
 362         return((ret == 0)?ret_code:ret);
 363         }
 364
 365 static int b64_write(BIO *b, const char *in, int inl)
 366         {
 367         int ret=inl,n,i;
 368         BIO_B64_CTX *ctx;
 369
 370         ctx=(BIO_B64_CTX *)b->ptr;
 371         BIO_clear_retry_flags(b);
 372
 373         if (ctx->encode != B64_ENCODE)
 374                 {
 375                 ctx->encode=B64_ENCODE;
 376                 ctx->buf_len=0;
 377                 ctx->buf_off=0;
 378                 ctx->tmp_len=0;
 379                 EVP_EncodeInit(&(ctx->base64));
 380                 }
 381
 382         n=ctx->buf_len-ctx->buf_off;
 383         while (n > 0)
 384                 {
 385                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 386                 if (i <= 0)
 387                         {
 388                         BIO_copy_next_retry(b);
 389                         return(i);
 390                         }
 391                 ctx->buf_off+=i;
 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)) return(0);
 399
 400         while (inl > 0)
 401                 {
 402                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 403
 404                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 405                         {
 406                         if (ctx->tmp_len > 0)
 407                                 {
 408                                 n=3-ctx->tmp_len;
 409                                 /* There's a teoretical possibility for this */
 410                                 if (n > inl)
 411                                         n=inl;
 412                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 413                                 ctx->tmp_len+=n;
 414                                 if (ctx->tmp_len < 3)
 415                                         break;
 416                                 ctx->buf_len=EVP_EncodeBlock(
 417                                         (unsigned char *)ctx->buf,
 418                                         (unsigned char *)ctx->tmp,
 419                                         ctx->tmp_len);
 420                                 /* Since we're now done using the temporary
 421                                    buffer, the length should be 0'd */
 422                                 ctx->tmp_len=0;
 423                                 }
 424                         else
 425                                 {
 426                                 if (n < 3)
 427                                         {
 428                                         memcpy(&(ctx->tmp[0]),in,n);
 429                                         ctx->tmp_len=n;
 430                                         break;
 431                                         }
 432                                 n-=n%3;
 433                                 ctx->buf_len=EVP_EncodeBlock(
 434                                         (unsigned char *)ctx->buf,
 435                                         (unsigned char *)in,n);
 436                                 }
 437                         }
 438                 else
 439                         {
 440                         EVP_EncodeUpdate(&(ctx->base64),
 441                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 442                                 (unsigned char *)in,n);
 443                         }
 444                 inl-=n;
 445                 in+=n;
 446
 447                 ctx->buf_off=0;
 448                 n=ctx->buf_len;
 449                 while (n > 0)
 450                         {
 451                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 452                         if (i <= 0)
 453                                 {
 454                                 BIO_copy_next_retry(b);
 455                                 return((ret == 0)?i:ret);
 456                                 }
 457                         n-=i;
 458                         ctx->buf_off+=i;
 459                         }
 460                 ctx->buf_len=0;
 461                 ctx->buf_off=0;
 462                 }
 463         return(ret);
 464         }
 465
 466 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
 467         {
 468         BIO_B64_CTX *ctx;
 469         long ret=1;
 470         int i;
 471
 472         ctx=(BIO_B64_CTX *)b->ptr;
 473
 474         switch (cmd)
 475                 {
 476         case BIO_CTRL_RESET:
 477                 ctx->cont=1;
 478                 ctx->start=1;
 479                 ctx->encode=B64_NONE;
 480                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 481                 break;
 482         case BIO_CTRL_EOF:      /* More to read */
 483                 if (ctx->cont <= 0)
 484                         ret=1;
 485                 else
 486                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 487                 break;
 488         case BIO_CTRL_WPENDING: /* More to write in buffer */
 489                 ret=ctx->buf_len-ctx->buf_off;
 490                 if ((ret == 0) && (ctx->encode != B64_NONE)
 491                         && (ctx->base64.num != 0))
 492                         ret=1;
 493                 else if (ret <= 0)
 494                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 495                 break;
 496         case BIO_CTRL_PENDING: /* More to read in buffer */
 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                         {
 506                         i=b64_write(b,NULL,0);
 507                         if (i < 0)
 508                                 return i;
 509                         }
 510                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 511                         {
 512                         if (ctx->tmp_len != 0)
 513                                 {
 514                                 ctx->buf_len=EVP_EncodeBlock(
 515                                         (unsigned char *)ctx->buf,
 516                                         (unsigned char *)ctx->tmp,
 517                                         ctx->tmp_len);
 518                                 ctx->buf_off=0;
 519                                 ctx->tmp_len=0;
 520                                 goto again;
 521                                 }
 522                         }
 523                 else if (ctx->encode != B64_NONE && ctx->base64.num != 0)
 524                         {
 525                         ctx->buf_off=0;
 526                         EVP_EncodeFinal(&(ctx->base64),
 527                                 (unsigned char *)ctx->buf,
 528                                 &(ctx->buf_len));
 529                         /* push out the bytes */
 530                         goto again;
 531                         }
 532                 /* Finally flush the underlying BIO */
 533                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 534                 break;
 535
 536         case BIO_C_DO_STATE_MACHINE:
 537                 BIO_clear_retry_flags(b);
 538                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 539                 BIO_copy_next_retry(b);
 540                 break;
 541
 542         case BIO_CTRL_DUP:
 543                 break;
 544         case BIO_CTRL_INFO:
 545         case BIO_CTRL_GET:
 546         case BIO_CTRL_SET:
 547         default:
 548                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 549                 break;
 550                 }
 551         return(ret);
 552         }
 553
 554 static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 555         {
 556         long ret=1;
 557
 558         if (b->next_bio == NULL) return(0);
 559         switch (cmd)
 560                 {
 561         default:
 562                 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
 563                 break;
 564                 }
 565         return(ret);
 566         }
 567