crypto/evp/bio_b64.c

   1 /* crypto/evp/bio_b64.c */
   2 /* Copyright (C) 1995-1997 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_NONE        0
  85 #define B64_ENCODE      1
  86 #define B64_DECODE      2
  87
  88 typedef struct b64_struct
  89         {
  90         /*BIO *bio; moved to the BIO structure */
  91         int buf_len;
  92         int buf_off;
  93         int tmp_len;            /* used to find the start when decoding */
  94         int tmp_nl;             /* If true, scan until '\n' */
  95         int encode;
  96         int start;              /* have we started decoding yet? */
  97         int cont;               /* <= 0 when finished */
  98         EVP_ENCODE_CTX base64;
  99         char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE)+10];
 100         char tmp[B64_BLOCK_SIZE];
 101         } BIO_B64_CTX;
 102
 103 static BIO_METHOD methods_b64=
 104         {
 105         BIO_TYPE_BASE64,"base64 encoding",
 106         b64_write,
 107         b64_read,
 108         NULL, /* b64_puts, */
 109         NULL, /* b64_gets, */
 110         b64_ctrl,
 111         b64_new,
 112         b64_free,
 113         };
 114
 115 BIO_METHOD *BIO_f_base64()
 116         {
 117         return(&methods_b64);
 118         }
 119
 120 static int b64_new(bi)
 121 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(a)
 143 BIO *a;
 144         {
 145         if (a == NULL) return(0);
 146         Free(a->ptr);
 147         a->ptr=NULL;
 148         a->init=0;
 149         a->flags=0;
 150         return(1);
 151         }
 152
 153 static int b64_read(b,out,outl)
 154 BIO *b;
 155 char *out;
 156 int outl;
 157         {
 158         int ret=0,i,ii,j,k,x,n,num;
 159         BIO_B64_CTX *ctx;
 160         unsigned char *p,*q;
 161
 162         if (out == NULL) return(0);
 163         ctx=(BIO_B64_CTX *)b->ptr;
 164
 165         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 166
 167         if (ctx->encode != B64_DECODE)
 168                 {
 169                 ctx->encode=B64_DECODE;
 170                 ctx->buf_len=0;
 171                 ctx->buf_off=0;
 172                 EVP_DecodeInit(&(ctx->base64));
 173                 }
 174
 175         /* First check if there are bytes decoded/encoded */
 176         if (ctx->buf_len > 0)
 177                 {
 178                 i=ctx->buf_len-ctx->buf_off;
 179                 if (i > outl) i=outl;
 180                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 181                 ret=i;
 182                 out+=i;
 183                 outl-=i;
 184                 ctx->buf_off+=i;
 185                 if (ctx->buf_len == ctx->buf_off)
 186                         {
 187                         ctx->buf_len=0;
 188                         ctx->buf_off=0;
 189                         }
 190                 }
 191
 192         /* At this point, we have room of outl bytes and an empty
 193          * buffer, so we should read in some more. */
 194
 195         while (outl > 0)
 196                 {
 197                 if (ctx->cont <= 0) break;
 198
 199                 i=BIO_read(b->next_bio,&(ctx->tmp[ctx->tmp_len]),
 200                         B64_BLOCK_SIZE-ctx->tmp_len);
 201
 202                 if (i <= 0)
 203                         {
 204                         /* Should be continue next time we are called? */
 205                         if (!BIO_should_retry(b->next_bio))
 206                                 ctx->cont=i;
 207                         break;
 208                         }
 209                 i+=ctx->tmp_len;
 210
 211                 /* We need to scan, a line at a time until we
 212                  * have a valid line if we are starting. */
 213                 if (ctx->start)
 214                         {
 215                         q=p=(unsigned char *)ctx->tmp;
 216                         for (j=0; j<i; j++)
 217                                 {
 218                                 if (*(q++) != '\n') continue;
 219
 220                                 /* due to a previous very long line,
 221                                  * we need to keep on scanning for a '\n'
 222                                  * before we even start looking for
 223                                  * base64 encoded stuff. */
 224                                 if (ctx->tmp_nl)
 225                                         {
 226                                         p=q;
 227                                         ctx->tmp_nl=0;
 228                                         continue;
 229                                         }
 230
 231                                 k=EVP_DecodeUpdate(&(ctx->base64),
 232                                         (unsigned char *)ctx->buf,
 233                                         &num,p,q-p);
 234                                 if ((k <= 0) && (num == 0) && (ctx->start))
 235                                         EVP_DecodeInit(&ctx->base64);
 236                                 else
 237                                         {
 238                                         if (p != (unsigned char *)
 239                                                 &(ctx->tmp[0]))
 240                                                 {
 241                                                 i-=(p- (unsigned char *)
 242                                                         &(ctx->tmp[0]));
 243                                                 for (x=0; x < i; x++)
 244                                                         ctx->tmp[x]=p[x];
 245                                                 EVP_DecodeInit(&ctx->base64);
 246                                                 }
 247                                         ctx->start=0;
 248                                         break;
 249                                         }
 250                                 p=q;
 251                                 }
 252
 253                         /* we fell off the end without starting */
 254                         if (j == i)
 255                                 {
 256                                 /* Is this is one long chunk?, if so, keep on
 257                                  * reading until a new line. */
 258                                 if (p == (unsigned char *)&(ctx->tmp[0]))
 259                                         {
 260                                         ctx->tmp_nl=1;
 261                                         ctx->tmp_len=0;
 262                                         }
 263                                 else if (p != q) /* finished on a '\n' */
 264                                         {
 265                                         n=q-p;
 266                                         for (ii=0; ii<n; ii++)
 267                                                 ctx->tmp[ii]=p[ii];
 268                                         ctx->tmp_len=n;
 269                                         }
 270                                 /* else finished on a '\n' */
 271                                 continue;
 272                                 }
 273                         else
 274                                 ctx->tmp_len=0;
 275                         }
 276                 i=EVP_DecodeUpdate(&(ctx->base64),
 277                         (unsigned char *)ctx->buf,&ctx->buf_len,
 278                         (unsigned char *)ctx->tmp,i);
 279                 ctx->cont=i;
 280                 ctx->buf_off=0;
 281                 if (i < 0)
 282                         {
 283                         ctx->buf_len=0;
 284                         break;
 285                         }
 286
 287                 if (ctx->buf_len <= outl)
 288                         i=ctx->buf_len;
 289                 else
 290                         i=outl;
 291
 292                 memcpy(out,ctx->buf,i);
 293                 ret+=i;
 294                 ctx->buf_off=i;
 295                 if (ctx->buf_off == ctx->buf_len)
 296                         {
 297                         ctx->buf_len=0;
 298                         ctx->buf_off=0;
 299                         }
 300                 outl-=i;
 301                 out+=i;
 302                 }
 303         BIO_clear_retry_flags(b);
 304         BIO_copy_next_retry(b);
 305         return((ret == 0)?ctx->cont:ret);
 306         }
 307
 308 static int b64_write(b,in,inl)
 309 BIO *b;
 310 char *in;
 311 int inl;
 312         {
 313         int ret=inl,n,i;
 314         BIO_B64_CTX *ctx;
 315
 316         ctx=(BIO_B64_CTX *)b->ptr;
 317         BIO_clear_retry_flags(b);
 318
 319         if (ctx->encode != B64_ENCODE)
 320                 {
 321                 ctx->encode=B64_ENCODE;
 322                 ctx->buf_len=0;
 323                 ctx->buf_off=0;
 324                 EVP_EncodeInit(&(ctx->base64));
 325                 }
 326
 327         n=ctx->buf_len-ctx->buf_off;
 328         while (n > 0)
 329                 {
 330                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 331                 if (i <= 0)
 332                         {
 333                         BIO_copy_next_retry(b);
 334                         return(i);
 335                         }
 336                 ctx->buf_off+=i;
 337                 n-=i;
 338                 }
 339         /* at this point all pending data has been written */
 340
 341         if ((in == NULL) || (inl <= 0)) return(0);
 342
 343         ctx->buf_off=0;
 344         while (inl > 0)
 345                 {
 346                 n=(inl > B64_BLOCK_SIZE)?B64_BLOCK_SIZE:inl;
 347                 EVP_EncodeUpdate(&(ctx->base64),
 348                         (unsigned char *)ctx->buf,&ctx->buf_len,
 349                         (unsigned char *)in,n);
 350                 inl-=n;
 351                 in+=n;
 352
 353                 ctx->buf_off=0;
 354                 n=ctx->buf_len;
 355                 while (n > 0)
 356                         {
 357                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 358                         if (i <= 0)
 359                                 {
 360                                 BIO_copy_next_retry(b);
 361                                 return((ret == 0)?i:ret);
 362                                 }
 363                         n-=i;
 364                         ctx->buf_off+=i;
 365                         }
 366                 ctx->buf_len=0;
 367                 ctx->buf_off=0;
 368                 }
 369         return(ret);
 370         }
 371
 372 static long b64_ctrl(b,cmd,num,ptr)
 373 BIO *b;
 374 int cmd;
 375 long num;
 376 char *ptr;
 377         {
 378         BIO_B64_CTX *ctx;
 379         long ret=1;
 380         int i;
 381
 382         ctx=(BIO_B64_CTX *)b->ptr;
 383
 384         switch (cmd)
 385                 {
 386         case BIO_CTRL_RESET:
 387                 ctx->cont=1;
 388                 ctx->start=1;
 389                 ctx->encode=B64_NONE;
 390                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 391                 break;
 392         case BIO_CTRL_EOF:      /* More to read */
 393                 if (ctx->cont <= 0)
 394                         ret=1;
 395                 else
 396                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 397                 break;
 398         case BIO_CTRL_WPENDING: /* More to write in buffer */
 399                 ret=ctx->buf_len-ctx->buf_off;
 400                 if ((ret == 0) && (ctx->base64.num != 0))
 401                         ret=1;
 402                 else if (ret <= 0)
 403                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 404                 break;
 405         case BIO_CTRL_PENDING: /* More to read in buffer */
 406                 ret=ctx->buf_len-ctx->buf_off;
 407                 if (ret <= 0)
 408                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 409                 break;
 410         case BIO_CTRL_FLUSH:
 411                 /* do a final write */
 412 again:
 413                 while (ctx->buf_len != ctx->buf_off)
 414                         {
 415                         i=b64_write(b,NULL,0);
 416                         if (i < 0)
 417                                 {
 418                                 ret=i;
 419                                 break;
 420                                 }
 421                         }
 422                 if (ctx->base64.num != 0)
 423                         {
 424                         ctx->buf_off=0;
 425                         EVP_EncodeFinal(&(ctx->base64),
 426                                 (unsigned char *)ctx->buf,
 427                                 &(ctx->buf_len));
 428                         /* push out the bytes */
 429                         goto again;
 430                         }
 431                 /* Finally flush the underlying BIO */
 432                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 433                 break;
 434
 435         case BIO_C_DO_STATE_MACHINE:
 436                 BIO_clear_retry_flags(b);
 437                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 438                 BIO_copy_next_retry(b);
 439                 break;
 440
 441         case BIO_CTRL_DUP:
 442                 break;
 443         case BIO_CTRL_INFO:
 444         case BIO_CTRL_GET:
 445         case BIO_CTRL_SET:
 446         default:
 447                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 448                 break;
 449                 }
 450         return(ret);
 451         }
 452