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()
 117         {
 118         return(&methods_b64);
 119         }
 120
 121 static int b64_new(bi)
 122 BIO *bi;
 123         {
 124         BIO_B64_CTX *ctx;
 125
 126         ctx=(BIO_B64_CTX *)Malloc(sizeof(BIO_B64_CTX));
 127         if (ctx == NULL) return(0);
 128
 129         ctx->buf_len=0;
 130         ctx->tmp_len=0;
 131         ctx->tmp_nl=0;
 132         ctx->buf_off=0;
 133         ctx->cont=1;
 134         ctx->start=1;
 135         ctx->encode=0;
 136
 137         bi->init=1;
 138         bi->ptr=(char *)ctx;
 139         bi->flags=0;
 140         return(1);
 141         }
 142
 143 static int b64_free(a)
 144 BIO *a;
 145         {
 146         if (a == NULL) return(0);
 147         Free(a->ptr);
 148         a->ptr=NULL;
 149         a->init=0;
 150         a->flags=0;
 151         return(1);
 152         }
 153
 154 static int b64_read(b,out,outl)
 155 BIO *b;
 156 char *out;
 157 int outl;
 158         {
 159         int ret=0,i,ii,j,k,x,n,num,ret_code=0;
 160         BIO_B64_CTX *ctx;
 161         unsigned char *p,*q;
 162
 163         if (out == NULL) return(0);
 164         ctx=(BIO_B64_CTX *)b->ptr;
 165
 166         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 167
 168         if (ctx->encode != B64_DECODE)
 169                 {
 170                 ctx->encode=B64_DECODE;
 171                 ctx->buf_len=0;
 172                 ctx->buf_off=0;
 173                 ctx->tmp_len=0;
 174                 EVP_DecodeInit(&(ctx->base64));
 175                 }
 176
 177         /* First check if there are bytes decoded/encoded */
 178         if (ctx->buf_len > 0)
 179                 {
 180                 i=ctx->buf_len-ctx->buf_off;
 181                 if (i > outl) i=outl;
 182                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 183                 ret=i;
 184                 out+=i;
 185                 outl-=i;
 186                 ctx->buf_off+=i;
 187                 if (ctx->buf_len == ctx->buf_off)
 188                         {
 189                         ctx->buf_len=0;
 190                         ctx->buf_off=0;
 191                         }
 192                 }
 193
 194         /* At this point, we have room of outl bytes and an empty
 195          * buffer, so we should read in some more. */
 196
 197         ret_code=0;
 198         while (outl > 0)
 199                 {
 200                 if (ctx->cont <= 0) break;
 201
 202                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 203                         B64_BLOCK_SIZE-ctx->tmp_len);
 204
 205                 if (i <= 0)
 206                         {
 207                         ret_code=i;
 208
 209                         /* Should be continue next time we are called? */
 210                         if (!BIO_should_retry(b->next_bio))
 211                                 ctx->cont=i;
 212                         /* else we should continue when called again */
 213                         break;
 214                         }
 215                 i+=ctx->tmp_len;
 216
 217                 /* We need to scan, a line at a time until we
 218                  * have a valid line if we are starting. */
 219                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 220                         {
 221                         /* ctx->start=1; */
 222                         ctx->tmp_len=0;
 223                         }
 224                 else if (ctx->start)
 225                         {
 226                         q=p=(unsigned char *)ctx->tmp;
 227                         for (j=0; j<i; j++)
 228                                 {
 229                                 if (*(q++) != '\n') continue;
 230
 231                                 /* due to a previous very long line,
 232                                  * we need to keep on scanning for a '\n'
 233                                  * before we even start looking for
 234                                  * base64 encoded stuff. */
 235                                 if (ctx->tmp_nl)
 236                                         {
 237                                         p=q;
 238                                         ctx->tmp_nl=0;
 239                                         continue;
 240                                         }
 241
 242                                 k=EVP_DecodeUpdate(&(ctx->base64),
 243                                         (unsigned char *)ctx->buf,
 244                                         &num,p,q-p);
 245                                 if ((k <= 0) && (num == 0) && (ctx->start))
 246                                         EVP_DecodeInit(&ctx->base64);
 247                                 else
 248                                         {
 249                                         if (p != (unsigned char *)
 250                                                 &(ctx->tmp[0]))
 251                                                 {
 252                                                 i-=(p- (unsigned char *)
 253                                                         &(ctx->tmp[0]));
 254                                                 for (x=0; x < i; x++)
 255                                                         ctx->tmp[x]=p[x];
 256                                                 EVP_DecodeInit(&ctx->base64);
 257                                                 }
 258                                         ctx->start=0;
 259                                         break;
 260                                         }
 261                                 p=q;
 262                                 }
 263
 264                         /* we fell off the end without starting */
 265                         if (j == i)
 266                                 {
 267                                 /* Is this is one long chunk?, if so, keep on
 268                                  * reading until a new line. */
 269                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 270                                         {
 271                                         ctx->tmp_nl=1;
 272                                         ctx->tmp_len=0;
 273                                         }
 274                                 else if (p != q) /* finished on a '\n' */
 275                                         {
 276                                         n=q-p;
 277                                         for (ii=0; ii<n; ii++)
 278                                                 ctx->tmp[ii]=p[ii];
 279                                         ctx->tmp_len=n;
 280                                         }
 281                                 /* else finished on a '\n' */
 282                                 continue;
 283                                 }
 284                         else
 285                                 ctx->tmp_len=0;
 286                         }
 287
 288                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 289                         {
 290                         int z,jj;
 291
 292                         jj=(i>>2)<<2;
 293                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 294                                 (unsigned char *)ctx->tmp,jj);
 295                         if (jj > 2)
 296                                 {
 297                                 if (ctx->tmp[jj-1] == '=')
 298                                         {
 299                                         z--;
 300                                         if (ctx->tmp[jj-2] == '=')
 301                                                 z--;
 302                                         }
 303                                 }
 304                         /* z is now number of output bytes and jj is the
 305                          * number consumed */
 306                         if (jj != i)
 307                                 {
 308                                 memcpy((unsigned char *)ctx->tmp,
 309                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 310                                 ctx->tmp_len=i-jj;
 311                                 }
 312                         ctx->buf_len=0;
 313                         if (z > 0)
 314                                 {
 315                                 ctx->buf_len=z;
 316                                 i=1;
 317                                 }
 318                         else
 319                                 i=z;
 320                         }
 321                 else
 322                         {
 323                         i=EVP_DecodeUpdate(&(ctx->base64),
 324                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 325                                 (unsigned char *)ctx->tmp,i);
 326                         }
 327                 ctx->cont=i;
 328                 ctx->buf_off=0;
 329                 if (i < 0)
 330                         {
 331                         ret_code=0;
 332                         ctx->buf_len=0;
 333                         break;
 334                         }
 335
 336                 if (ctx->buf_len <= outl)
 337                         i=ctx->buf_len;
 338                 else
 339                         i=outl;
 340
 341                 memcpy(out,ctx->buf,i);
 342                 ret+=i;
 343                 ctx->buf_off=i;
 344                 if (ctx->buf_off == ctx->buf_len)
 345                         {
 346                         ctx->buf_len=0;
 347                         ctx->buf_off=0;
 348                         }
 349                 outl-=i;
 350                 out+=i;
 351                 }
 352         BIO_clear_retry_flags(b);
 353         BIO_copy_next_retry(b);
 354         return((ret == 0)?ret_code:ret);
 355         }
 356
 357 static int b64_write(b,in,inl)
 358 BIO *b;
 359 char *in;
 360 int inl;
 361         {
 362         int ret=inl,n,i;
 363         BIO_B64_CTX *ctx;
 364
 365         ctx=(BIO_B64_CTX *)b->ptr;
 366         BIO_clear_retry_flags(b);
 367
 368         if (ctx->encode != B64_ENCODE)
 369                 {
 370                 ctx->encode=B64_ENCODE;
 371                 ctx->buf_len=0;
 372                 ctx->buf_off=0;
 373                 ctx->tmp_len=0;
 374                 EVP_EncodeInit(&(ctx->base64));
 375                 }
 376
 377         n=ctx->buf_len-ctx->buf_off;
 378         while (n > 0)
 379                 {
 380                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 381                 if (i <= 0)
 382                         {
 383                         BIO_copy_next_retry(b);
 384                         return(i);
 385                         }
 386                 ctx->buf_off+=i;
 387                 n-=i;
 388                 }
 389         /* at this point all pending data has been written */
 390
 391         if ((in == NULL) || (inl <= 0)) return(0);
 392
 393         ctx->buf_off=0;
 394         while (inl > 0)
 395                 {
 396                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 397
 398                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 399                         {
 400                         if (ctx->tmp_len > 0)
 401                                 {
 402                                 n=3-ctx->tmp_len;
 403                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 404                                 ctx->tmp_len+=n;
 405                                 n=ctx->tmp_len;
 406                                 if (n < 3)
 407                                         break;
 408                                 ctx->buf_len=EVP_EncodeBlock(
 409                                         (unsigned char *)ctx->buf,
 410                                         (unsigned char *)ctx->tmp,n);
 411                                 }
 412                         else
 413                                 {
 414                                 if (n < 3)
 415                                         {
 416                                         memcpy(&(ctx->tmp[0]),in,n);
 417                                         ctx->tmp_len=n;
 418                                         break;
 419                                         }
 420                                 n-=n%3;
 421                                 ctx->buf_len=EVP_EncodeBlock(
 422                                         (unsigned char *)ctx->buf,
 423                                         (unsigned char *)in,n);
 424                                 }
 425                         }
 426                 else
 427                         {
 428                         EVP_EncodeUpdate(&(ctx->base64),
 429                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 430                                 (unsigned char *)in,n);
 431                         }
 432                 inl-=n;
 433                 in+=n;
 434
 435                 ctx->buf_off=0;
 436                 n=ctx->buf_len;
 437                 while (n > 0)
 438                         {
 439                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 440                         if (i <= 0)
 441                                 {
 442                                 BIO_copy_next_retry(b);
 443                                 return((ret == 0)?i:ret);
 444                                 }
 445                         n-=i;
 446                         ctx->buf_off+=i;
 447                         }
 448                 ctx->buf_len=0;
 449                 ctx->buf_off=0;
 450                 }
 451         return(ret);
 452         }
 453
 454 static long b64_ctrl(b,cmd,num,ptr)
 455 BIO *b;
 456 int cmd;
 457 long num;
 458 char *ptr;
 459         {
 460         BIO_B64_CTX *ctx;
 461         long ret=1;
 462         int i;
 463
 464         ctx=(BIO_B64_CTX *)b->ptr;
 465
 466         switch (cmd)
 467                 {
 468         case BIO_CTRL_RESET:
 469                 ctx->cont=1;
 470                 ctx->start=1;
 471                 ctx->encode=B64_NONE;
 472                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 473                 break;
 474         case BIO_CTRL_EOF:      /* More to read */
 475                 if (ctx->cont <= 0)
 476                         ret=1;
 477                 else
 478                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 479                 break;
 480         case BIO_CTRL_WPENDING: /* More to write in buffer */
 481                 ret=ctx->buf_len-ctx->buf_off;
 482                 if ((ret == 0) && (ctx->base64.num != 0))
 483                         ret=1;
 484                 else if (ret <= 0)
 485                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 486                 break;
 487         case BIO_CTRL_PENDING: /* More to read in buffer */
 488                 ret=ctx->buf_len-ctx->buf_off;
 489                 if (ret <= 0)
 490                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 491                 break;
 492         case BIO_CTRL_FLUSH:
 493                 /* do a final write */
 494 again:
 495                 while (ctx->buf_len != ctx->buf_off)
 496                         {
 497                         i=b64_write(b,NULL,0);
 498                         if (i < 0)
 499                                 {
 500                                 ret=i;
 501                                 break;
 502                                 }
 503                         }
 504                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 505                         {
 506                         if (ctx->tmp_len != 0)
 507                                 {
 508                                 ctx->buf_len=EVP_EncodeBlock(
 509                                         (unsigned char *)ctx->buf,
 510                                         (unsigned char *)ctx->tmp,
 511                                         ctx->tmp_len);
 512                                 ctx->buf_off=0;
 513                                 ctx->tmp_len=0;
 514                                 goto again;
 515                                 }
 516                         }
 517                 else if (ctx->base64.num != 0)
 518                         {
 519                         ctx->buf_off=0;
 520                         EVP_EncodeFinal(&(ctx->base64),
 521                                 (unsigned char *)ctx->buf,
 522                                 &(ctx->buf_len));
 523                         /* push out the bytes */
 524                         goto again;
 525                         }
 526                 /* Finally flush the underlying BIO */
 527                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 528                 break;
 529
 530         case BIO_C_DO_STATE_MACHINE:
 531                 BIO_clear_retry_flags(b);
 532                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 533                 BIO_copy_next_retry(b);
 534                 break;
 535
 536         case BIO_CTRL_DUP:
 537                 break;
 538         case BIO_CTRL_INFO:
 539         case BIO_CTRL_GET:
 540         case BIO_CTRL_SET:
 541         default:
 542                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 543                 break;
 544                 }
 545         return(ret);
 546         }
 547