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,char *buf,int num);
  66 static int b64_read(BIO *h,char *buf,int size);
  67 /*static int b64_puts(BIO *h,char *str); */
  68 /*static int b64_gets(BIO *h,char *str,int size); */
  69 static long b64_ctrl(BIO *h,int cmd,long arg1,char *arg2);
  70 static int b64_new(BIO *h);
  71 static int b64_free(BIO *data);
  72 #define B64_BLOCK_SIZE  1024
  73 #define B64_BLOCK_SIZE2 768
  74 #define B64_NONE        0
  75 #define B64_ENCODE      1
  76 #define B64_DECODE      2
  77
  78 typedef struct b64_struct
  79         {
  80         /*BIO *bio; moved to the BIO structure */
  81         int buf_len;
  82         int buf_off;
  83         int tmp_len;            /* used to find the start when decoding */
  84         int tmp_nl;             /* If true, scan until '\n' */
  85         int encode;
  86         int start;              /* have we started decoding yet? */
  87         int cont;               /* <= 0 when finished */
  88         EVP_ENCODE_CTX base64;
  89         char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE)+10];
  90         char tmp[B64_BLOCK_SIZE];
  91         } BIO_B64_CTX;
  92
  93 static BIO_METHOD methods_b64=
  94         {
  95         BIO_TYPE_BASE64,"base64 encoding",
  96         b64_write,
  97         b64_read,
  98         NULL, /* b64_puts, */
  99         NULL, /* b64_gets, */
 100         b64_ctrl,
 101         b64_new,
 102         b64_free,
 103         };
 104
 105 BIO_METHOD *BIO_f_base64(void)
 106         {
 107         return(&methods_b64);
 108         }
 109
 110 static int b64_new(BIO *bi)
 111         {
 112         BIO_B64_CTX *ctx;
 113
 114         ctx=(BIO_B64_CTX *)Malloc(sizeof(BIO_B64_CTX));
 115         if (ctx == NULL) return(0);
 116
 117         ctx->buf_len=0;
 118         ctx->tmp_len=0;
 119         ctx->tmp_nl=0;
 120         ctx->buf_off=0;
 121         ctx->cont=1;
 122         ctx->start=1;
 123         ctx->encode=0;
 124
 125         bi->init=1;
 126         bi->ptr=(char *)ctx;
 127         bi->flags=0;
 128         return(1);
 129         }
 130
 131 static int b64_free(BIO *a)
 132         {
 133         if (a == NULL) return(0);
 134         Free(a->ptr);
 135         a->ptr=NULL;
 136         a->init=0;
 137         a->flags=0;
 138         return(1);
 139         }
 140
 141 static int b64_read(BIO *b, char *out, int outl)
 142         {
 143         int ret=0,i,ii,j,k,x,n,num,ret_code=0;
 144         BIO_B64_CTX *ctx;
 145         unsigned char *p,*q;
 146
 147         if (out == NULL) return(0);
 148         ctx=(BIO_B64_CTX *)b->ptr;
 149
 150         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 151
 152         if (ctx->encode != B64_DECODE)
 153                 {
 154                 ctx->encode=B64_DECODE;
 155                 ctx->buf_len=0;
 156                 ctx->buf_off=0;
 157                 ctx->tmp_len=0;
 158                 EVP_DecodeInit(&(ctx->base64));
 159                 }
 160
 161         /* First check if there are bytes decoded/encoded */
 162         if (ctx->buf_len > 0)
 163                 {
 164                 i=ctx->buf_len-ctx->buf_off;
 165                 if (i > outl) i=outl;
 166                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 167                 ret=i;
 168                 out+=i;
 169                 outl-=i;
 170                 ctx->buf_off+=i;
 171                 if (ctx->buf_len == ctx->buf_off)
 172                         {
 173                         ctx->buf_len=0;
 174                         ctx->buf_off=0;
 175                         }
 176                 }
 177
 178         /* At this point, we have room of outl bytes and an empty
 179          * buffer, so we should read in some more. */
 180
 181         ret_code=0;
 182         while (outl > 0)
 183                 {
 184                 if (ctx->cont <= 0) break;
 185
 186                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 187                         B64_BLOCK_SIZE-ctx->tmp_len);
 188
 189                 if (i <= 0)
 190                         {
 191                         ret_code=i;
 192
 193                         /* Should be continue next time we are called? */
 194                         if (!BIO_should_retry(b->next_bio))
 195                                 ctx->cont=i;
 196                         /* else we should continue when called again */
 197                         break;
 198                         }
 199                 i+=ctx->tmp_len;
 200
 201                 /* We need to scan, a line at a time until we
 202                  * have a valid line if we are starting. */
 203                 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL))
 204                         {
 205                         /* ctx->start=1; */
 206                         ctx->tmp_len=0;
 207                         }
 208                 else if (ctx->start)
 209                         {
 210                         q=p=(unsigned char *)ctx->tmp;
 211                         for (j=0; j<i; j++)
 212                                 {
 213                                 if (*(q++) != '\n') continue;
 214
 215                                 /* due to a previous very long line,
 216                                  * we need to keep on scanning for a '\n'
 217                                  * before we even start looking for
 218                                  * base64 encoded stuff. */
 219                                 if (ctx->tmp_nl)
 220                                         {
 221                                         p=q;
 222                                         ctx->tmp_nl=0;
 223                                         continue;
 224                                         }
 225
 226                                 k=EVP_DecodeUpdate(&(ctx->base64),
 227                                         (unsigned char *)ctx->buf,
 228                                         &num,p,q-p);
 229                                 if ((k <= 0) && (num == 0) && (ctx->start))
 230                                         EVP_DecodeInit(&ctx->base64);
 231                                 else
 232                                         {
 233                                         if (p != (unsigned char *)
 234                                                 &(ctx->tmp[0]))
 235                                                 {
 236                                                 i-=(p- (unsigned char *)
 237                                                         &(ctx->tmp[0]));
 238                                                 for (x=0; x < i; x++)
 239                                                         ctx->tmp[x]=p[x];
 240                                                 EVP_DecodeInit(&ctx->base64);
 241                                                 }
 242                                         ctx->start=0;
 243                                         break;
 244                                         }
 245                                 p=q;
 246                                 }
 247
 248                         /* we fell off the end without starting */
 249                         if (j == i)
 250                                 {
 251                                 /* Is this is one long chunk?, if so, keep on
 252                                  * reading until a new line. */
 253                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 254                                         {
 255                                         ctx->tmp_nl=1;
 256                                         ctx->tmp_len=0;
 257                                         }
 258                                 else if (p != q) /* finished on a '\n' */
 259                                         {
 260                                         n=q-p;
 261                                         for (ii=0; ii<n; ii++)
 262                                                 ctx->tmp[ii]=p[ii];
 263                                         ctx->tmp_len=n;
 264                                         }
 265                                 /* else finished on a '\n' */
 266                                 continue;
 267                                 }
 268                         else
 269                                 ctx->tmp_len=0;
 270                         }
 271
 272                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 273                         {
 274                         int z,jj;
 275
 276                         jj=(i>>2)<<2;
 277                         z=EVP_DecodeBlock((unsigned char *)ctx->buf,
 278                                 (unsigned char *)ctx->tmp,jj);
 279                         if (jj > 2)
 280                                 {
 281                                 if (ctx->tmp[jj-1] == '=')
 282                                         {
 283                                         z--;
 284                                         if (ctx->tmp[jj-2] == '=')
 285                                                 z--;
 286                                         }
 287                                 }
 288                         /* z is now number of output bytes and jj is the
 289                          * number consumed */
 290                         if (jj != i)
 291                                 {
 292                                 memcpy((unsigned char *)ctx->tmp,
 293                                         (unsigned char *)&(ctx->tmp[jj]),i-jj);
 294                                 ctx->tmp_len=i-jj;
 295                                 }
 296                         ctx->buf_len=0;
 297                         if (z > 0)
 298                                 {
 299                                 ctx->buf_len=z;
 300                                 i=1;
 301                                 }
 302                         else
 303                                 i=z;
 304                         }
 305                 else
 306                         {
 307                         i=EVP_DecodeUpdate(&(ctx->base64),
 308                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 309                                 (unsigned char *)ctx->tmp,i);
 310                         }
 311                 ctx->cont=i;
 312                 ctx->buf_off=0;
 313                 if (i < 0)
 314                         {
 315                         ret_code=0;
 316                         ctx->buf_len=0;
 317                         break;
 318                         }
 319
 320                 if (ctx->buf_len <= outl)
 321                         i=ctx->buf_len;
 322                 else
 323                         i=outl;
 324
 325                 memcpy(out,ctx->buf,i);
 326                 ret+=i;
 327                 ctx->buf_off=i;
 328                 if (ctx->buf_off == ctx->buf_len)
 329                         {
 330                         ctx->buf_len=0;
 331                         ctx->buf_off=0;
 332                         }
 333                 outl-=i;
 334                 out+=i;
 335                 }
 336         BIO_clear_retry_flags(b);
 337         BIO_copy_next_retry(b);
 338         return((ret == 0)?ret_code:ret);
 339         }
 340
 341 static int b64_write(BIO *b, char *in, int inl)
 342         {
 343         int ret=inl,n,i;
 344         BIO_B64_CTX *ctx;
 345
 346         ctx=(BIO_B64_CTX *)b->ptr;
 347         BIO_clear_retry_flags(b);
 348
 349         if (ctx->encode != B64_ENCODE)
 350                 {
 351                 ctx->encode=B64_ENCODE;
 352                 ctx->buf_len=0;
 353                 ctx->buf_off=0;
 354                 ctx->tmp_len=0;
 355                 EVP_EncodeInit(&(ctx->base64));
 356                 }
 357
 358         n=ctx->buf_len-ctx->buf_off;
 359         while (n > 0)
 360                 {
 361                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 362                 if (i <= 0)
 363                         {
 364                         BIO_copy_next_retry(b);
 365                         return(i);
 366                         }
 367                 ctx->buf_off+=i;
 368                 n-=i;
 369                 }
 370         /* at this point all pending data has been written */
 371
 372         if ((in == NULL) || (inl <= 0)) return(0);
 373
 374         ctx->buf_off=0;
 375         while (inl > 0)
 376                 {
 377                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 378
 379                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 380                         {
 381                         if (ctx->tmp_len > 0)
 382                                 {
 383                                 n=3-ctx->tmp_len;
 384                                 memcpy(&(ctx->tmp[ctx->tmp_len]),in,n);
 385                                 ctx->tmp_len+=n;
 386                                 n=ctx->tmp_len;
 387                                 if (n < 3)
 388                                         break;
 389                                 ctx->buf_len=EVP_EncodeBlock(
 390                                         (unsigned char *)ctx->buf,
 391                                         (unsigned char *)ctx->tmp,n);
 392                                 }
 393                         else
 394                                 {
 395                                 if (n < 3)
 396                                         {
 397                                         memcpy(&(ctx->tmp[0]),in,n);
 398                                         ctx->tmp_len=n;
 399                                         break;
 400                                         }
 401                                 n-=n%3;
 402                                 ctx->buf_len=EVP_EncodeBlock(
 403                                         (unsigned char *)ctx->buf,
 404                                         (unsigned char *)in,n);
 405                                 }
 406                         }
 407                 else
 408                         {
 409                         EVP_EncodeUpdate(&(ctx->base64),
 410                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 411                                 (unsigned char *)in,n);
 412                         }
 413                 inl-=n;
 414                 in+=n;
 415
 416                 ctx->buf_off=0;
 417                 n=ctx->buf_len;
 418                 while (n > 0)
 419                         {
 420                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 421                         if (i <= 0)
 422                                 {
 423                                 BIO_copy_next_retry(b);
 424                                 return((ret == 0)?i:ret);
 425                                 }
 426                         n-=i;
 427                         ctx->buf_off+=i;
 428                         }
 429                 ctx->buf_len=0;
 430                 ctx->buf_off=0;
 431                 }
 432         return(ret);
 433         }
 434
 435 static long b64_ctrl(BIO *b, int cmd, long num, char *ptr)
 436         {
 437         BIO_B64_CTX *ctx;
 438         long ret=1;
 439         int i;
 440
 441         ctx=(BIO_B64_CTX *)b->ptr;
 442
 443         switch (cmd)
 444                 {
 445         case BIO_CTRL_RESET:
 446                 ctx->cont=1;
 447                 ctx->start=1;
 448                 ctx->encode=B64_NONE;
 449                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 450                 break;
 451         case BIO_CTRL_EOF:      /* More to read */
 452                 if (ctx->cont <= 0)
 453                         ret=1;
 454                 else
 455                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 456                 break;
 457         case BIO_CTRL_WPENDING: /* More to write in buffer */
 458                 ret=ctx->buf_len-ctx->buf_off;
 459                 if ((ret == 0) && (ctx->base64.num != 0))
 460                         ret=1;
 461                 else if (ret <= 0)
 462                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 463                 break;
 464         case BIO_CTRL_PENDING: /* More to read in buffer */
 465                 ret=ctx->buf_len-ctx->buf_off;
 466                 if (ret <= 0)
 467                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 468                 break;
 469         case BIO_CTRL_FLUSH:
 470                 /* do a final write */
 471 again:
 472                 while (ctx->buf_len != ctx->buf_off)
 473                         {
 474                         i=b64_write(b,NULL,0);
 475                         if (i < 0)
 476                                 {
 477                                 ret=i;
 478                                 break;
 479                                 }
 480                         }
 481                 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
 482                         {
 483                         if (ctx->tmp_len != 0)
 484                                 {
 485                                 ctx->buf_len=EVP_EncodeBlock(
 486                                         (unsigned char *)ctx->buf,
 487                                         (unsigned char *)ctx->tmp,
 488                                         ctx->tmp_len);
 489                                 ctx->buf_off=0;
 490                                 ctx->tmp_len=0;
 491                                 goto again;
 492                                 }
 493                         }
 494                 else if (ctx->base64.num != 0)
 495                         {
 496                         ctx->buf_off=0;
 497                         EVP_EncodeFinal(&(ctx->base64),
 498                                 (unsigned char *)ctx->buf,
 499                                 &(ctx->buf_len));
 500                         /* push out the bytes */
 501                         goto again;
 502                         }
 503                 /* Finally flush the underlying BIO */
 504                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 505                 break;
 506
 507         case BIO_C_DO_STATE_MACHINE:
 508                 BIO_clear_retry_flags(b);
 509                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 510                 BIO_copy_next_retry(b);
 511                 break;
 512
 513         case BIO_CTRL_DUP:
 514                 break;
 515         case BIO_CTRL_INFO:
 516         case BIO_CTRL_GET:
 517         case BIO_CTRL_SET:
 518         default:
 519                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 520                 break;
 521                 }
 522         return(ret);
 523         }
 524