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                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 169                 ret=i;
 170                 out+=i;
 171                 outl-=i;
 172                 ctx->buf_off+=i;
 173                 if (ctx->buf_len == ctx->buf_off)
 174                         {
 175                         ctx->buf_len=0;
 176                         ctx->buf_off=0;
 177                         }
 178                 }
 179
 180         /* At this point, we have room of outl bytes and an empty
 181          * buffer, so we should read in some more. */
 182
 183         ret_code=0;
 184         while (outl > 0)
 185                 {
 186                 if (ctx->cont <= 0) break;
 187
 188                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 189                         B64_BLOCK_SIZE-ctx->tmp_len);
 190
 191                 if (i <= 0)
 192                         {
 193                         ret_code=i;
 194
 195                         /* Should be continue next time we are called? */
 196                         if (!BIO_should_retry(b->next_bio))
 197                                 ctx->cont=i;
 198                         /* else we should continue when called again */
 199                         break;
 200                         }
 201                 i+=ctx->tmp_len;
 202
 203                 /* We need to scan, a line at a time until we
 204                  * have a valid line if we are starting. */
 205                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 206                         {
 207                         /* ctx->start=1; */
 208                         ctx->tmp_len=0;
 209                         }
 210                 else if (ctx->start)
 211                         {
 212                         q=p=(unsigned char *)ctx->tmp;
 213                         for (j=0; j<i; j++)
 214                                 {
 215                                 if (*(q++) != '\n') continue;
 216
 217                                 /* due to a previous very long line,
 218                                  * we need to keep on scanning for a '\n'
 219                                  * before we even start looking for
 220                                  * base64 encoded stuff. */
 221                                 if (ctx->tmp_nl)
 222                                         {
 223                                         p=q;
 224                                         ctx->tmp_nl=0;
 225                                         continue;
 226                                         }
 227
 228                                 k=EVP_DecodeUpdate(&(ctx->base64),
 229                                         (unsigned char *)ctx->buf,
 230                                         &num,p,q-p);
 231                                 if ((k <= 0) && (num == 0) && (ctx->start))
 232                                         EVP_DecodeInit(&ctx->base64);
 233                                 else
 234                                         {
 235                                         if (p != (unsigned char *)
 236                                                 &(ctx->tmp[0]))
 237                                                 {
 238                                                 i-=(p- (unsigned char *)
 239                                                         &(ctx->tmp[0]));
 240                                                 for (x=0; x < i; x++)
 241                                                         ctx->tmp[x]=p[x];
 242                                                 }
 243                                         EVP_DecodeInit(&ctx->base64);
 244                                         ctx->start=0;
 245                                         break;
 246                                         }
 247                                 p=q;
 248                                 }
 249
 250                         /* we fell off the end without starting */
 251                         if (j == i)
 252                                 {
 253                                 /* Is this is one long chunk?, if so, keep on
 254                                  * reading until a new line. */
 255                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 256                                         {
 257                                         ctx->tmp_nl=1;
 258                                         ctx->tmp_len=0;
 259                                         }
 260                                 else if (p != q) /* finished on a '\n' */
 261                                         {
 262                                         n=q-p;
 263                                         for (ii=0; ii<n; ii++)
 264                                                 ctx->tmp[ii]=p[ii];
 265                                         ctx->tmp_len=n;
 266                                         }
 267                                 /* else finished on a '\n' */
 268                                 continue;
 269                                 }
 270                         else
 271                                 ctx->tmp_len=0;
 272                         }
 273
 274                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 275                         {
 276                         int z,jj;
 277
 278                         jj=(i>>2)<<2;
 279                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 280                                 (unsigned char *)ctx->tmp,jj);
 281                         if (jj > 2)
 282                                 {
 283                                 if (ctx->tmp[jj-1] == '=')
 284                                         {
 285                                         z--;
 286                                         if (ctx->tmp[jj-2] == '=')
 287                                                 z--;
 288                                         }
 289                                 }
 290                         /* z is now number of output bytes and jj is the
 291                          * number consumed */
 292                         if (jj != i)
 293                                 {
 294                                 memcpy((unsigned char *)ctx->tmp,
 295                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 296                                 ctx->tmp_len=i-jj;
 297                                 }
 298                         ctx->buf_len=0;
 299                         if (z > 0)
 300                                 {
 301                                 ctx->buf_len=z;
 302                                 i=1;
 303                                 }
 304                         else
 305                                 i=z;
 306                         }
 307                 else
 308                         {
 309                         i=EVP_DecodeUpdate(&(ctx->base64),
 310                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 311                                 (unsigned char *)ctx->tmp,i);
 312                         }
 313                 ctx->cont=i;
 314                 ctx->buf_off=0;
 315                 if (i < 0)
 316                         {
 317                         ret_code=0;
 318                         ctx->buf_len=0;
 319                         break;
 320                         }
 321
 322                 if (ctx->buf_len <= outl)
 323                         i=ctx->buf_len;
 324                 else
 325                         i=outl;
 326
 327                 memcpy(out,ctx->buf,i);
 328                 ret+=i;
 329                 ctx->buf_off=i;
 330                 if (ctx->buf_off == ctx->buf_len)
 331                         {
 332                         ctx->buf_len=0;
 333                         ctx->buf_off=0;
 334                         }
 335                 outl-=i;
 336                 out+=i;
 337                 }
 338         BIO_clear_retry_flags(b);
 339         BIO_copy_next_retry(b);
 340         return((ret == 0)?ret_code:ret);
 341         }
 342
 343 static int b64_write(BIO *b, const char *in, int inl)
 344         {
 345         int ret=inl,n,i;
 346         BIO_B64_CTX *ctx;
 347
 348         ctx=(BIO_B64_CTX *)b->ptr;
 349         BIO_clear_retry_flags(b);
 350
 351         if (ctx->encode != B64_ENCODE)
 352                 {
 353                 ctx->encode=B64_ENCODE;
 354                 ctx->buf_len=0;
 355                 ctx->buf_off=0;
 356                 ctx->tmp_len=0;
 357                 EVP_EncodeInit(&(ctx->base64));
 358                 }
 359
 360         n=ctx->buf_len-ctx->buf_off;
 361         while (n > 0)
 362                 {
 363                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 364                 if (i <= 0)
 365                         {
 366                         BIO_copy_next_retry(b);
 367                         return(i);
 368                         }
 369                 ctx->buf_off+=i;
 370                 n-=i;
 371                 }
 372         /* at this point all pending data has been written */
 373
 374         if ((in == NULL) || (inl <= 0)) return(0);
 375
 376         ctx->buf_off=0;
 377         while (inl > 0)
 378                 {
 379                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 380
 381                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 382                         {
 383                         if (ctx->tmp_len > 0)
 384                                 {
 385                                 n=3-ctx->tmp_len;
 386                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 387                                 ctx->tmp_len+=n;
 388                                 n=ctx->tmp_len;
 389                                 if (n < 3)
 390                                         break;
 391                                 ctx->buf_len=EVP_EncodeBlock(
 392                                         (unsigned char *)ctx->buf,
 393                                         (unsigned char *)ctx->tmp,n);
 394                                 }
 395                         else
 396                                 {
 397                                 if (n < 3)
 398                                         {
 399                                         memcpy(&(ctx->tmp[0]),in,n);
 400                                         ctx->tmp_len=n;
 401                                         break;
 402                                         }
 403                                 n-=n%3;
 404                                 ctx->buf_len=EVP_EncodeBlock(
 405                                         (unsigned char *)ctx->buf,
 406                                         (unsigned char *)in,n);
 407                                 }
 408                         }
 409                 else
 410                         {
 411                         EVP_EncodeUpdate(&(ctx->base64),
 412                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 413                                 (unsigned char *)in,n);
 414                         }
 415                 inl-=n;
 416                 in+=n;
 417
 418                 ctx->buf_off=0;
 419                 n=ctx->buf_len;
 420                 while (n > 0)
 421                         {
 422                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 423                         if (i <= 0)
 424                                 {
 425                                 BIO_copy_next_retry(b);
 426                                 return((ret == 0)?i:ret);
 427                                 }
 428                         n-=i;
 429                         ctx->buf_off+=i;
 430                         }
 431                 ctx->buf_len=0;
 432                 ctx->buf_off=0;
 433                 }
 434         return(ret);
 435         }
 436
 437 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
 438         {
 439         BIO_B64_CTX *ctx;
 440         long ret=1;
 441         int i;
 442
 443         ctx=(BIO_B64_CTX *)b->ptr;
 444
 445         switch (cmd)
 446                 {
 447         case BIO_CTRL_RESET:
 448                 ctx->cont=1;
 449                 ctx->start=1;
 450                 ctx->encode=B64_NONE;
 451                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 452                 break;
 453         case BIO_CTRL_EOF:      /* More to read */
 454                 if (ctx->cont <= 0)
 455                         ret=1;
 456                 else
 457                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 458                 break;
 459         case BIO_CTRL_WPENDING: /* More to write in buffer */
 460                 ret=ctx->buf_len-ctx->buf_off;
 461                 if ((ret == 0) && (ctx->base64.num != 0))
 462                         ret=1;
 463                 else if (ret <= 0)
 464                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 465                 break;
 466         case BIO_CTRL_PENDING: /* More to read in buffer */
 467                 ret=ctx->buf_len-ctx->buf_off;
 468                 if (ret <= 0)
 469                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 470                 break;
 471         case BIO_CTRL_FLUSH:
 472                 /* do a final write */
 473 again:
 474                 while (ctx->buf_len != ctx->buf_off)
 475                         {
 476                         i=b64_write(b,NULL,0);
 477                         if (i < 0)
 478                                 {
 479                                 ret=i;
 480                                 break;
 481                                 }
 482                         }
 483                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 484                         {
 485                         if (ctx->tmp_len != 0)
 486                                 {
 487                                 ctx->buf_len=EVP_EncodeBlock(
 488                                         (unsigned char *)ctx->buf,
 489                                         (unsigned char *)ctx->tmp,
 490                                         ctx->tmp_len);
 491                                 ctx->buf_off=0;
 492                                 ctx->tmp_len=0;
 493                                 goto again;
 494                                 }
 495                         }
 496                 else if (ctx->base64.num != 0)
 497                         {
 498                         ctx->buf_off=0;
 499                         EVP_EncodeFinal(&(ctx->base64),
 500                                 (unsigned char *)ctx->buf,
 501                                 &(ctx->buf_len));
 502                         /* push out the bytes */
 503                         goto again;
 504                         }
 505                 /* Finally flush the underlying BIO */
 506                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 507                 break;
 508
 509         case BIO_C_DO_STATE_MACHINE:
 510                 BIO_clear_retry_flags(b);
 511                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 512                 BIO_copy_next_retry(b);
 513                 break;
 514
 515         case BIO_CTRL_DUP:
 516                 break;
 517         case BIO_CTRL_INFO:
 518         case BIO_CTRL_GET:
 519         case BIO_CTRL_SET:
 520         default:
 521                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 522                 break;
 523                 }
 524         return(ret);
 525         }
 526
 527 static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 528         {
 529         long ret=1;
 530
 531         if (b->next_bio == NULL) return(0);
 532         switch (cmd)
 533                 {
 534         default:
 535                 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
 536                 break;
 537                 }
 538         return(ret);
 539         }
 540