crypto/evp/bio_enc.c

   1 /* crypto/evp/bio_enc.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 enc_write(BIO *h,char *buf,int num);
  67 static int enc_read(BIO *h,char *buf,int size);
  68 /*static int enc_puts(BIO *h,char *str); */
  69 /*static int enc_gets(BIO *h,char *str,int size); */
  70 static long enc_ctrl(BIO *h,int cmd,long arg1,char *arg2);
  71 static int enc_new(BIO *h);
  72 static int enc_free(BIO *data);
  73 #else
  74 static int enc_write();
  75 static int enc_read();
  76 /*static int enc_puts(); */
  77 /*static int enc_gets(); */
  78 static long enc_ctrl();
  79 static int enc_new();
  80 static int enc_free();
  81 #endif
  82
  83 #define ENC_BLOCK_SIZE  (1024*4)
  84
  85 typedef struct enc_struct
  86         {
  87         int buf_len;
  88         int buf_off;
  89         int cont;               /* <= 0 when finished */
  90         int finished;
  91         int ok;                 /* bad decrypt */
  92         EVP_CIPHER_CTX cipher;
  93         char buf[ENC_BLOCK_SIZE+10];
  94         } BIO_ENC_CTX;
  95
  96 static BIO_METHOD methods_enc=
  97         {
  98         BIO_TYPE_CIPHER,"cipher",
  99         enc_write,
 100         enc_read,
 101         NULL, /* enc_puts, */
 102         NULL, /* enc_gets, */
 103         enc_ctrl,
 104         enc_new,
 105         enc_free,
 106         };
 107
 108 BIO_METHOD *BIO_f_cipher()
 109         {
 110         return(&methods_enc);
 111         }
 112
 113 static int enc_new(bi)
 114 BIO *bi;
 115         {
 116         BIO_ENC_CTX *ctx;
 117
 118         ctx=(BIO_ENC_CTX *)Malloc(sizeof(BIO_ENC_CTX));
 119         if (ctx == NULL) return(0);
 120
 121         ctx->buf_len=0;
 122         ctx->buf_off=0;
 123         ctx->cont=1;
 124         ctx->finished=0;
 125         ctx->ok=1;
 126
 127         bi->init=0;
 128         bi->ptr=(char *)ctx;
 129         bi->flags=0;
 130         return(1);
 131         }
 132
 133 static int enc_free(a)
 134 BIO *a;
 135         {
 136         BIO_ENC_CTX *b;
 137
 138         if (a == NULL) return(0);
 139         b=(BIO_ENC_CTX *)a->ptr;
 140         EVP_CIPHER_CTX_cleanup(&(b->cipher));
 141         memset(a->ptr,0,sizeof(BIO_ENC_CTX));
 142         Free(a->ptr);
 143         a->ptr=NULL;
 144         a->init=0;
 145         a->flags=0;
 146         return(1);
 147         }
 148
 149 static int enc_read(b,out,outl)
 150 BIO *b;
 151 char *out;
 152 int outl;
 153         {
 154         int ret=0,i;
 155         BIO_ENC_CTX *ctx;
 156
 157         if (out == NULL) return(0);
 158         ctx=(BIO_ENC_CTX *)b->ptr;
 159
 160         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 161
 162         /* First check if there are bytes decoded/encoded */
 163         if (ctx->buf_len > 0)
 164                 {
 165                 i=ctx->buf_len-ctx->buf_off;
 166                 if (i > outl) i=outl;
 167                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 168                 ret=i;
 169                 out+=i;
 170                 outl-=i;
 171                 ctx->buf_off+=i;
 172                 if (ctx->buf_len == ctx->buf_off)
 173                         {
 174                         ctx->buf_len=0;
 175                         ctx->buf_off=0;
 176                         }
 177                 }
 178
 179         /* At this point, we have room of outl bytes and an empty
 180          * buffer, so we should read in some more. */
 181
 182         while (outl > 0)
 183                 {
 184                 if (ctx->cont <= 0) break;
 185
 186                 /* read in at offset 8, read the EVP_Cipher
 187                  * documentation about why */
 188                 i=BIO_read(b->next_bio,&(ctx->buf[8]),ENC_BLOCK_SIZE);
 189
 190                 if (i <= 0)
 191                         {
 192                         /* Should be continue next time we are called? */
 193                         if (!BIO_should_retry(b->next_bio))
 194                                 {
 195                                 ctx->cont=i;
 196                                 i=EVP_CipherFinal(&(ctx->cipher),
 197                                         (unsigned char *)ctx->buf,
 198                                         &(ctx->buf_len));
 199                                 ctx->ok=i;
 200                                 ctx->buf_off=0;
 201                                 }
 202                         else
 203                                 ret=(ret == 0)?i:ret;
 204                         break;
 205                         }
 206                 else
 207                         {
 208                         EVP_CipherUpdate(&(ctx->cipher),
 209                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 210                                 (unsigned char *)&(ctx->buf[8]),i);
 211                         ctx->cont=1;
 212                         }
 213
 214                 if (ctx->buf_len <= outl)
 215                         i=ctx->buf_len;
 216                 else
 217                         i=outl;
 218
 219                 if (i <= 0) break;
 220                 memcpy(out,ctx->buf,i);
 221                 ret+=i;
 222                 ctx->buf_off=i;
 223                 outl-=i;
 224                 out+=i;
 225                 }
 226
 227         BIO_clear_retry_flags(b);
 228         BIO_copy_next_retry(b);
 229         return((ret == 0)?ctx->cont:ret);
 230         }
 231
 232 static int enc_write(b,in,inl)
 233 BIO *b;
 234 char *in;
 235 int inl;
 236         {
 237         int ret=0,n,i;
 238         BIO_ENC_CTX *ctx;
 239
 240         ctx=(BIO_ENC_CTX *)b->ptr;
 241         ret=inl;
 242
 243         BIO_clear_retry_flags(b);
 244         n=ctx->buf_len-ctx->buf_off;
 245         while (n > 0)
 246                 {
 247                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 248                 if (i <= 0)
 249                         {
 250                         BIO_copy_next_retry(b);
 251                         return(i);
 252                         }
 253                 ctx->buf_off+=i;
 254                 n-=i;
 255                 }
 256         /* at this point all pending data has been written */
 257
 258         if ((in == NULL) || (inl <= 0)) return(0);
 259
 260         ctx->buf_off=0;
 261         while (inl > 0)
 262                 {
 263                 n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl;
 264                 EVP_CipherUpdate(&(ctx->cipher),
 265                         (unsigned char *)ctx->buf,&ctx->buf_len,
 266                         (unsigned char *)in,n);
 267                 inl-=n;
 268                 in+=n;
 269
 270                 ctx->buf_off=0;
 271                 n=ctx->buf_len;
 272                 while (n > 0)
 273                         {
 274                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 275                         if (i <= 0)
 276                                 {
 277                                 BIO_copy_next_retry(b);
 278                                 return(i);
 279                                 }
 280                         n-=i;
 281                         ctx->buf_off+=i;
 282                         }
 283                 ctx->buf_len=0;
 284                 ctx->buf_off=0;
 285                 }
 286         BIO_copy_next_retry(b);
 287         return(ret);
 288         }
 289
 290 static long enc_ctrl(b,cmd,num,ptr)
 291 BIO *b;
 292 int cmd;
 293 long num;
 294 char *ptr;
 295         {
 296         BIO *dbio;
 297         BIO_ENC_CTX *ctx,*dctx;
 298         long ret=1;
 299         int i;
 300
 301         ctx=(BIO_ENC_CTX *)b->ptr;
 302
 303         switch (cmd)
 304                 {
 305         case BIO_CTRL_RESET:
 306                 ctx->ok=1;
 307                 ctx->finished=0;
 308                 EVP_CipherInit(&(ctx->cipher),NULL,NULL,NULL,
 309                         ctx->cipher.encrypt);
 310                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 311                 break;
 312         case BIO_CTRL_EOF:      /* More to read */
 313                 if (ctx->cont <= 0)
 314                         ret=1;
 315                 else
 316                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 317                 break;
 318         case BIO_CTRL_WPENDING:
 319                 ret=ctx->buf_len-ctx->buf_off;
 320                 if (ret <= 0)
 321                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 322                 break;
 323         case BIO_CTRL_PENDING: /* More to read in buffer */
 324                 ret=ctx->buf_len-ctx->buf_off;
 325                 if (ret <= 0)
 326                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 327                 break;
 328         case BIO_CTRL_FLUSH:
 329                 /* do a final write */
 330 again:
 331                 while (ctx->buf_len != ctx->buf_off)
 332                         {
 333                         i=enc_write(b,NULL,0);
 334                         if (i < 0)
 335                                 {
 336                                 ret=i;
 337                                 break;
 338                                 }
 339                         }
 340
 341                 if (!ctx->finished)
 342                         {
 343                         ctx->finished=1;
 344                         ctx->buf_off=0;
 345                         ret=EVP_CipherFinal(&(ctx->cipher),
 346                                 (unsigned char *)ctx->buf,
 347                                 &(ctx->buf_len));
 348                         ctx->ok=(int)ret;
 349                         if (ret <= 0) break;
 350
 351                         /* push out the bytes */
 352                         goto again;
 353                         }
 354
 355                 /* Finally flush the underlying BIO */
 356                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 357                 break;
 358         case BIO_C_GET_CIPHER_STATUS:
 359                 ret=(long)ctx->ok;
 360                 break;
 361         case BIO_C_DO_STATE_MACHINE:
 362                 BIO_clear_retry_flags(b);
 363                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 364                 BIO_copy_next_retry(b);
 365                 break;
 366
 367         case BIO_CTRL_DUP:
 368                 dbio=(BIO *)ptr;
 369                 dctx=(BIO_ENC_CTX *)dbio->ptr;
 370                 memcpy(&(dctx->cipher),&(ctx->cipher),sizeof(ctx->cipher));
 371                 dbio->init=1;
 372                 break;
 373         default:
 374                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 375                 break;
 376                 }
 377         return(ret);
 378         }
 379
 380 void BIO_set_cipher(b,c,k,i,e)
 381 BIO *b;
 382 EVP_CIPHER *c;
 383 unsigned char *k;
 384 unsigned char *i;
 385 int e;
 386         {
 387         BIO_ENC_CTX *ctx;
 388
 389         if (b == NULL) return;
 390
 391         if ((b->callback != NULL) &&
 392                 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
 393                 return;
 394
 395         b->init=1;
 396         ctx=(BIO_ENC_CTX *)b->ptr;
 397         EVP_CipherInit(&(ctx->cipher),c,k,i,e);
 398
 399         if (b->callback != NULL)
 400                 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
 401         }
 402