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 < 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                 if (ctx->cont <= 0) break;
 188
 189                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 190                         B64_BLOCK_SIZE-ctx->tmp_len);
 191
 192                 if (i <= 0)
 193                         {
 194                         ret_code=i;
 195
 196                         /* Should be continue next time we are called? */
 197                         if (!BIO_should_retry(b->next_bio))
 198                                 ctx->cont=i;
 199                         /* else we should continue when called again */
 200                         break;
 201                         }
 202                 i+=ctx->tmp_len;
 203
 204                 /* We need to scan, a line at a time until we
 205                  * have a valid line if we are starting. */
 206                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 207                         {
 208                         /* ctx->start=1; */
 209                         ctx->tmp_len=0;
 210                         }
 211                 else if (ctx->start)
 212                         {
 213                         q=p=(unsigned char *)ctx->tmp;
 214                         for (j=0; j<i; j++)
 215                                 {
 216                                 if (*(q++) != '\n') continue;
 217
 218                                 /* due to a previous very long line,
 219                                  * we need to keep on scanning for a '\n'
 220                                  * before we even start looking for
 221                                  * base64 encoded stuff. */
 222                                 if (ctx->tmp_nl)
 223                                         {
 224                                         p=q;
 225                                         ctx->tmp_nl=0;
 226                                         continue;
 227                                         }
 228
 229                                 k=EVP_DecodeUpdate(&(ctx->base64),
 230                                         (unsigned char *)ctx->buf,
 231                                         &num,p,q-p);
 232                                 if ((k <= 0) && (num == 0) && (ctx->start))
 233                                         EVP_DecodeInit(&ctx->base64);
 234                                 else
 235                                         {
 236                                         if (p != (unsigned char *)
 237                                                 &(ctx->tmp[0]))
 238                                                 {
 239                                                 i-=(p- (unsigned char *)
 240                                                         &(ctx->tmp[0]));
 241                                                 for (x=0; x < i; x++)
 242                                                         ctx->tmp[x]=p[x];
 243                                                 }
 244                                         EVP_DecodeInit(&ctx->base64);
 245                                         ctx->start=0;
 246                                         break;
 247                                         }
 248                                 p=q;
 249                                 }
 250
 251                         /* we fell off the end without starting */
 252                         if (j == i)
 253                                 {
 254                                 /* Is this is one long chunk?, if so, keep on
 255                                  * reading until a new line. */
 256                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 257                                         {
 258                                         ctx->tmp_nl=1;
 259                                         ctx->tmp_len=0;
 260                                         }
 261                                 else if (p != q) /* finished on a '\n' */
 262                                         {
 263                                         n=q-p;
 264                                         for (ii=0; ii<n; ii++)
 265                                                 ctx->tmp[ii]=p[ii];
 266                                         ctx->tmp_len=n;
 267                                         }
 268                                 /* else finished on a '\n' */
 269                                 continue;
 270                                 }
 271                         else
 272                                 ctx->tmp_len=0;
 273                         }
 274
 275                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 276                         {
 277                         int z,jj;
 278
 279                         jj=(i>>2)<<2;
 280                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 281                                 (unsigned char *)ctx->tmp,jj);
 282                         if (jj > 2)
 283                                 {
 284                                 if (ctx->tmp[jj-1] == '=')
 285                                         {
 286                                         z--;
 287                                         if (ctx->tmp[jj-2] == '=')
 288                                                 z--;
 289                                         }
 290                                 }
 291                         /* z is now number of output bytes and jj is the
 292                          * number consumed */
 293                         if (jj != i)
 294                                 {
 295                                 memcpy((unsigned char *)ctx->tmp,
 296                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 297                                 ctx->tmp_len=i-jj;
 298                                 }
 299                         ctx->buf_len=0;
 300                         if (z > 0)
 301                                 {
 302                                 ctx->buf_len=z;
 303                                 i=1;
 304                                 }
 305                         else
 306                                 i=z;
 307                         }
 308                 else
 309                         {
 310                         i=EVP_DecodeUpdate(&(ctx->base64),
 311                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 312                                 (unsigned char *)ctx->tmp,i);
 313                         }
 314                 ctx->cont=i;
 315                 ctx->buf_off=0;
 316                 if (i < 0)
 317                         {
 318                         ret_code=0;
 319                         ctx->buf_len=0;
 320                         break;
 321                         }
 322
 323                 if (ctx->buf_len <= outl)
 324                         i=ctx->buf_len;
 325                 else
 326                         i=outl;
 327
 328                 memcpy(out,ctx->buf,i);
 329                 ret+=i;
 330                 ctx->buf_off=i;
 331                 if (ctx->buf_off == ctx->buf_len)
 332                         {
 333                         ctx->buf_len=0;
 334                         ctx->buf_off=0;
 335                         }
 336                 outl-=i;
 337                 out+=i;
 338                 }
 339         BIO_clear_retry_flags(b);
 340         BIO_copy_next_retry(b);
 341         return((ret == 0)?ret_code:ret);
 342         }
 343
 344 static int b64_write(BIO *b, const char *in, int inl)
 345         {
 346         int ret=inl,n,i;
 347         BIO_B64_CTX *ctx;
 348
 349         ctx=(BIO_B64_CTX *)b->ptr;
 350         BIO_clear_retry_flags(b);
 351
 352         if (ctx->encode != B64_ENCODE)
 353                 {
 354                 ctx->encode=B64_ENCODE;
 355                 ctx->buf_len=0;
 356                 ctx->buf_off=0;
 357                 ctx->tmp_len=0;
 358                 EVP_EncodeInit(&(ctx->base64));
 359                 }
 360
 361         n=ctx->buf_len-ctx->buf_off;
 362         while (n > 0)
 363                 {
 364                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 365                 if (i <= 0)
 366                         {
 367                         BIO_copy_next_retry(b);
 368                         return(i);
 369                         }
 370                 ctx->buf_off+=i;
 371                 n-=i;
 372                 }
 373         /* at this point all pending data has been written */
 374         ctx->buf_off=0;
 375         ctx->buf_len=0;
 376
 377         if ((in == NULL) || (inl <= 0)) return(0);
 378
 379         while (inl > 0)
 380                 {
 381                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 382
 383                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 384                         {
 385                         if (ctx->tmp_len > 0)
 386                                 {
 387                                 n=3-ctx->tmp_len;
 388                                 /* There's a teoretical possibility for this */
 389                                 if (n > inl)
 390                                         n=inl;
 391                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 392                                 ctx->tmp_len+=n;
 393                                 if (ctx->tmp_len < 3)
 394                                         break;
 395                                 ctx->buf_len=EVP_EncodeBlock(
 396                                         (unsigned char *)ctx->buf,
 397                                         (unsigned char *)ctx->tmp,
 398                                         ctx->tmp_len);
 399                                 /* Since we're now done using the temporary
 400                                    buffer, the length should be 0'd */
 401                                 ctx->tmp_len=0;
 402                                 }
 403                         else
 404                                 {
 405                                 if (n < 3)
 406                                         {
 407                                         memcpy(&(ctx->tmp[0]),in,n);
 408                                         ctx->tmp_len=n;
 409                                         break;
 410                                         }
 411                                 n-=n%3;
 412                                 ctx->buf_len=EVP_EncodeBlock(
 413                                         (unsigned char *)ctx->buf,
 414                                         (unsigned char *)in,n);
 415                                 }
 416                         }
 417                 else
 418                         {
 419                         EVP_EncodeUpdate(&(ctx->base64),
 420                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 421                                 (unsigned char *)in,n);
 422                         }
 423                 inl-=n;
 424                 in+=n;
 425
 426                 ctx->buf_off=0;
 427                 n=ctx->buf_len;
 428                 while (n > 0)
 429                         {
 430                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 431                         if (i <= 0)
 432                                 {
 433                                 BIO_copy_next_retry(b);
 434                                 return((ret == 0)?i:ret);
 435                                 }
 436                         n-=i;
 437                         ctx->buf_off+=i;
 438                         }
 439                 ctx->buf_len=0;
 440                 ctx->buf_off=0;
 441                 }
 442         return(ret);
 443         }
 444
 445 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
 446         {
 447         BIO_B64_CTX *ctx;
 448         long ret=1;
 449         int i;
 450
 451         ctx=(BIO_B64_CTX *)b->ptr;
 452
 453         switch (cmd)
 454                 {
 455         case BIO_CTRL_RESET:
 456                 ctx->cont=1;
 457                 ctx->start=1;
 458                 ctx->encode=B64_NONE;
 459                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 460                 break;
 461         case BIO_CTRL_EOF:      /* More to read */
 462                 if (ctx->cont <= 0)
 463                         ret=1;
 464                 else
 465                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 466                 break;
 467         case BIO_CTRL_WPENDING: /* More to write in buffer */
 468                 ret=ctx->buf_len-ctx->buf_off;
 469                 if ((ret == 0) && (ctx->encode != B64_NONE)
 470                         && (ctx->base64.num != 0))
 471                         ret=1;
 472                 else if (ret <= 0)
 473                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 474                 break;
 475         case BIO_CTRL_PENDING: /* More to read in buffer */
 476                 ret=ctx->buf_len-ctx->buf_off;
 477                 if (ret <= 0)
 478                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 479                 break;
 480         case BIO_CTRL_FLUSH:
 481                 /* do a final write */
 482 again:
 483                 while (ctx->buf_len != ctx->buf_off)
 484                         {
 485                         i=b64_write(b,NULL,0);
 486                         if (i < 0)
 487                                 {
 488                                 ret=i;
 489                                 break;
 490                                 }
 491                         }
 492                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 493                         {
 494                         if (ctx->tmp_len != 0)
 495                                 {
 496                                 ctx->buf_len=EVP_EncodeBlock(
 497                                         (unsigned char *)ctx->buf,
 498                                         (unsigned char *)ctx->tmp,
 499                                         ctx->tmp_len);
 500                                 ctx->buf_off=0;
 501                                 ctx->tmp_len=0;
 502                                 goto again;
 503                                 }
 504                         }
 505                 else if (ctx->encode != B64_NONE && ctx->base64.num != 0)
 506                         {
 507                         ctx->buf_off=0;
 508                         EVP_EncodeFinal(&(ctx->base64),
 509                                 (unsigned char *)ctx->buf,
 510                                 &(ctx->buf_len));
 511                         /* push out the bytes */
 512                         goto again;
 513                         }
 514                 /* Finally flush the underlying BIO */
 515                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 516                 break;
 517
 518         case BIO_C_DO_STATE_MACHINE:
 519                 BIO_clear_retry_flags(b);
 520                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 521                 BIO_copy_next_retry(b);
 522                 break;
 523
 524         case BIO_CTRL_DUP:
 525                 break;
 526         case BIO_CTRL_INFO:
 527         case BIO_CTRL_GET:
 528         case BIO_CTRL_SET:
 529         default:
 530                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 531                 break;
 532                 }
 533         return(ret);
 534         }
 535
 536 static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 537         {
 538         long ret=1;
 539
 540         if (b->next_bio == NULL) return(0);
 541         switch (cmd)
 542                 {
 543         default:
 544                 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
 545                 break;
 546                 }
 547         return(ret);
 548         }
 549