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 "buffer.h"
  63 #include "evp.h"
  64
  65 #ifndef NOPROTO
  66 static int b64_write(BIO *h,char *buf,int num);
  67 static int b64_read(BIO *h,char *buf,int size);
  68 /*static int b64_puts(BIO *h,char *str); */
  69 /*static int b64_gets(BIO *h,char *str,int size); */
  70 static long b64_ctrl(BIO *h,int cmd,long arg1,char *arg2);
  71 static int b64_new(BIO *h);
  72 static int b64_free(BIO *data);
  73 #else
  74 static int b64_write();
  75 static int b64_read();
  76 /*static int b64_puts(); */
  77 /*static int b64_gets(); */
  78 static long b64_ctrl();
  79 static int b64_new();
  80 static int b64_free();
  81 #endif
  82
  83 #define B64_BLOCK_SIZE  1024
  84 #define B64_BLOCK_SIZE2 768
  85 #define B64_NONE        0
  86 #define B64_ENCODE      1
  87 #define B64_DECODE      2
  88
  89 typedef struct b64_struct
  90         {
  91         /*BIO *bio; moved to the BIO structure */
  92         int buf_len;
  93         int buf_off;
  94         int tmp_len;            /* used to find the start when decoding */
  95         int tmp_nl;             /* If true, scan until '\n' */
  96         int encode;
  97         int start;              /* have we started decoding yet? */
  98         int cont;               /* <= 0 when finished */
  99         EVP_ENCODE_CTX base64;
 100         char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE)+10];
 101         char tmp[B64_BLOCK_SIZE];
 102         } BIO_B64_CTX;
 103
 104 static BIO_METHOD methods_b64=
 105         {
 106         BIO_TYPE_BASE64,"base64 encoding",
 107         b64_write,
 108         b64_read,
 109         NULL, /* b64_puts, */
 110         NULL, /* b64_gets, */
 111         b64_ctrl,
 112         b64_new,
 113         b64_free,
 114         };
 115
 116 BIO_METHOD *BIO_f_base64(void)
 117         {
 118         return(&methods_b64);
 119         }
 120
 121 static int b64_new(BIO *bi)
 122         {
 123         BIO_B64_CTX *ctx;
 124
 125         ctx=(BIO_B64_CTX *)Malloc(sizeof(BIO_B64_CTX));
 126         if (ctx == NULL) return(0);
 127
 128         ctx->buf_len=0;
 129         ctx->tmp_len=0;
 130         ctx->tmp_nl=0;
 131         ctx->buf_off=0;
 132         ctx->cont=1;
 133         ctx->start=1;
 134         ctx->encode=0;
 135
 136         bi->init=1;
 137         bi->ptr=(char *)ctx;
 138         bi->flags=0;
 139         return(1);
 140         }
 141
 142 static int b64_free(BIO *a)
 143         {
 144         if (a == NULL) return(0);
 145         Free(a->ptr);
 146         a->ptr=NULL;
 147         a->init=0;
 148         a->flags=0;
 149         return(1);
 150         }
 151
 152 static int b64_read(BIO *b, char *out, int outl)
 153         {
 154         int ret=0,i,ii,j,k,x,n,num,ret_code=0;
 155         BIO_B64_CTX *ctx;
 156         unsigned char *p,*q;
 157
 158         if (out == NULL) return(0);
 159         ctx=(BIO_B64_CTX *)b->ptr;
 160
 161         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 162
 163         if (ctx->encode != B64_DECODE)
 164                 {
 165                 ctx->encode=B64_DECODE;
 166                 ctx->buf_len=0;
 167                 ctx->buf_off=0;
 168                 ctx->tmp_len=0;
 169                 EVP_DecodeInit(&(ctx->base64));
 170                 }
 171
 172         /* First check if there are bytes decoded/encoded */
 173         if (ctx->buf_len > 0)
 174                 {
 175                 i=ctx->buf_len-ctx->buf_off;
 176                 if (i > outl) i=outl;
 177                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 178                 ret=i;
 179                 out+=i;
 180                 outl-=i;
 181                 ctx->buf_off+=i;
 182                 if (ctx->buf_len == ctx->buf_off)
 183                         {
 184                         ctx->buf_len=0;
 185                         ctx->buf_off=0;
 186                         }
 187                 }
 188
 189         /* At this point, we have room of outl bytes and an empty
 190          * buffer, so we should read in some more. */
 191
 192         ret_code=0;
 193         while (outl > 0)
 194                 {
 195                 if (ctx->cont <= 0) break;
 196
 197                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 198                         B64_BLOCK_SIZE-ctx->tmp_len);
 199
 200                 if (i <= 0)
 201                         {
 202                         ret_code=i;
 203
 204                         /* Should be continue next time we are called? */
 205                         if (!BIO_should_retry(b->next_bio))
 206                                 ctx->cont=i;
 207                         /* else we should continue when called again */
 208                         break;
 209                         }
 210                 i+=ctx->tmp_len;
 211
 212                 /* We need to scan, a line at a time until we
 213                  * have a valid line if we are starting. */
 214                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 215                         {
 216                         /* ctx->start=1; */
 217                         ctx->tmp_len=0;
 218                         }
 219                 else if (ctx->start)
 220                         {
 221                         q=p=(unsigned char *)ctx->tmp;
 222                         for (j=0; j<i; j++)
 223                                 {
 224                                 if (*(q++) != '\n') continue;
 225
 226                                 /* due to a previous very long line,
 227                                  * we need to keep on scanning for a '\n'
 228                                  * before we even start looking for
 229                                  * base64 encoded stuff. */
 230                                 if (ctx->tmp_nl)
 231                                         {
 232                                         p=q;
 233                                         ctx->tmp_nl=0;
 234                                         continue;
 235                                         }
 236
 237                                 k=EVP_DecodeUpdate(&(ctx->base64),
 238                                         (unsigned char *)ctx->buf,
 239                                         &num,p,q-p);
 240                                 if ((k <= 0) && (num == 0) && (ctx->start))
 241                                         EVP_DecodeInit(&ctx->base64);
 242                                 else
 243                                         {
 244                                         if (p != (unsigned char *)
 245                                                 &(ctx->tmp[0]))
 246                                                 {
 247                                                 i-=(p- (unsigned char *)
 248                                                         &(ctx->tmp[0]));
 249                                                 for (x=0; x < i; x++)
 250                                                         ctx->tmp[x]=p[x];
 251                                                 EVP_DecodeInit(&ctx->base64);
 252                                                 }
 253                                         ctx->start=0;
 254                                         break;
 255                                         }
 256                                 p=q;
 257                                 }
 258
 259                         /* we fell off the end without starting */
 260                         if (j == i)
 261                                 {
 262                                 /* Is this is one long chunk?, if so, keep on
 263                                  * reading until a new line. */
 264                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 265                                         {
 266                                         ctx->tmp_nl=1;
 267                                         ctx->tmp_len=0;
 268                                         }
 269                                 else if (p != q) /* finished on a '\n' */
 270                                         {
 271                                         n=q-p;
 272                                         for (ii=0; ii<n; ii++)
 273                                                 ctx->tmp[ii]=p[ii];
 274                                         ctx->tmp_len=n;
 275                                         }
 276                                 /* else finished on a '\n' */
 277                                 continue;
 278                                 }
 279                         else
 280                                 ctx->tmp_len=0;
 281                         }
 282
 283                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 284                         {
 285                         int z,jj;
 286
 287                         jj=(i>>2)<<2;
 288                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 289                                 (unsigned char *)ctx->tmp,jj);
 290                         if (jj > 2)
 291                                 {
 292                                 if (ctx->tmp[jj-1] == '=')
 293                                         {
 294                                         z--;
 295                                         if (ctx->tmp[jj-2] == '=')
 296                                                 z--;
 297                                         }
 298                                 }
 299                         /* z is now number of output bytes and jj is the
 300                          * number consumed */
 301                         if (jj != i)
 302                                 {
 303                                 memcpy((unsigned char *)ctx->tmp,
 304                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 305                                 ctx->tmp_len=i-jj;
 306                                 }
 307                         ctx->buf_len=0;
 308                         if (z > 0)
 309                                 {
 310                                 ctx->buf_len=z;
 311                                 i=1;
 312                                 }
 313                         else
 314                                 i=z;
 315                         }
 316                 else
 317                         {
 318                         i=EVP_DecodeUpdate(&(ctx->base64),
 319                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 320                                 (unsigned char *)ctx->tmp,i);
 321                         }
 322                 ctx->cont=i;
 323                 ctx->buf_off=0;
 324                 if (i < 0)
 325                         {
 326                         ret_code=0;
 327                         ctx->buf_len=0;
 328                         break;
 329                         }
 330
 331                 if (ctx->buf_len <= outl)
 332                         i=ctx->buf_len;
 333                 else
 334                         i=outl;
 335
 336                 memcpy(out,ctx->buf,i);
 337                 ret+=i;
 338                 ctx->buf_off=i;
 339                 if (ctx->buf_off == ctx->buf_len)
 340                         {
 341                         ctx->buf_len=0;
 342                         ctx->buf_off=0;
 343                         }
 344                 outl-=i;
 345                 out+=i;
 346                 }
 347         BIO_clear_retry_flags(b);
 348         BIO_copy_next_retry(b);
 349         return((ret == 0)?ret_code:ret);
 350         }
 351
 352 static int b64_write(BIO *b, char *in, int inl)
 353         {
 354         int ret=inl,n,i;
 355         BIO_B64_CTX *ctx;
 356
 357         ctx=(BIO_B64_CTX *)b->ptr;
 358         BIO_clear_retry_flags(b);
 359
 360         if (ctx->encode != B64_ENCODE)
 361                 {
 362                 ctx->encode=B64_ENCODE;
 363                 ctx->buf_len=0;
 364                 ctx->buf_off=0;
 365                 ctx->tmp_len=0;
 366                 EVP_EncodeInit(&(ctx->base64));
 367                 }
 368
 369         n=ctx->buf_len-ctx->buf_off;
 370         while (n > 0)
 371                 {
 372                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 373                 if (i <= 0)
 374                         {
 375                         BIO_copy_next_retry(b);
 376                         return(i);
 377                         }
 378                 ctx->buf_off+=i;
 379                 n-=i;
 380                 }
 381         /* at this point all pending data has been written */
 382
 383         if ((in == NULL) || (inl <= 0)) return(0);
 384
 385         ctx->buf_off=0;
 386         while (inl > 0)
 387                 {
 388                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 389
 390                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 391                         {
 392                         if (ctx->tmp_len > 0)
 393                                 {
 394                                 n=3-ctx->tmp_len;
 395                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 396                                 ctx->tmp_len+=n;
 397                                 n=ctx->tmp_len;
 398                                 if (n < 3)
 399                                         break;
 400                                 ctx->buf_len=EVP_EncodeBlock(
 401                                         (unsigned char *)ctx->buf,
 402                                         (unsigned char *)ctx->tmp,n);
 403                                 }
 404                         else
 405                                 {
 406                                 if (n < 3)
 407                                         {
 408                                         memcpy(&(ctx->tmp[0]),in,n);
 409                                         ctx->tmp_len=n;
 410                                         break;
 411                                         }
 412                                 n-=n%3;
 413                                 ctx->buf_len=EVP_EncodeBlock(
 414                                         (unsigned char *)ctx->buf,
 415                                         (unsigned char *)in,n);
 416                                 }
 417                         }
 418                 else
 419                         {
 420                         EVP_EncodeUpdate(&(ctx->base64),
 421                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 422                                 (unsigned char *)in,n);
 423                         }
 424                 inl-=n;
 425                 in+=n;
 426
 427                 ctx->buf_off=0;
 428                 n=ctx->buf_len;
 429                 while (n > 0)
 430                         {
 431                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 432                         if (i <= 0)
 433                                 {
 434                                 BIO_copy_next_retry(b);
 435                                 return((ret == 0)?i:ret);
 436                                 }
 437                         n-=i;
 438                         ctx->buf_off+=i;
 439                         }
 440                 ctx->buf_len=0;
 441                 ctx->buf_off=0;
 442                 }
 443         return(ret);
 444         }
 445
 446 static long b64_ctrl(BIO *b, int cmd, long num, char *ptr)
 447         {
 448         BIO_B64_CTX *ctx;
 449         long ret=1;
 450         int i;
 451
 452         ctx=(BIO_B64_CTX *)b->ptr;
 453
 454         switch (cmd)
 455                 {
 456         case BIO_CTRL_RESET:
 457                 ctx->cont=1;
 458                 ctx->start=1;
 459                 ctx->encode=B64_NONE;
 460                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 461                 break;
 462         case BIO_CTRL_EOF:      /* More to read */
 463                 if (ctx->cont <= 0)
 464                         ret=1;
 465                 else
 466                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 467                 break;
 468         case BIO_CTRL_WPENDING: /* More to write in buffer */
 469                 ret=ctx->buf_len-ctx->buf_off;
 470                 if ((ret == 0) && (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->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