crypto/evp/bio_enc.c

   1 /* crypto/evp/bio_enc.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 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(void)
 109         {
 110         return(&methods_enc);
 111         }
 112
 113 static int enc_new(BIO *bi)
 114         {
 115         BIO_ENC_CTX *ctx;
 116
 117         ctx=(BIO_ENC_CTX *)Malloc(sizeof(BIO_ENC_CTX));
 118         EVP_CIPHER_CTX_init(&ctx->cipher);
 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(BIO *a)
 134         {
 135         BIO_ENC_CTX *b;
 136
 137         if (a == NULL) return(0);
 138         b=(BIO_ENC_CTX *)a->ptr;
 139         EVP_CIPHER_CTX_cleanup(&(b->cipher));
 140         memset(a->ptr,0,sizeof(BIO_ENC_CTX));
 141         Free(a->ptr);
 142         a->ptr=NULL;
 143         a->init=0;
 144         a->flags=0;
 145         return(1);
 146         }
 147
 148 static int enc_read(BIO *b, char *out, int outl)
 149         {
 150         int ret=0,i;
 151         BIO_ENC_CTX *ctx;
 152
 153         if (out == NULL) return(0);
 154         ctx=(BIO_ENC_CTX *)b->ptr;
 155
 156         if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
 157
 158         /* First check if there are bytes decoded/encoded */
 159         if (ctx->buf_len > 0)
 160                 {
 161                 i=ctx->buf_len-ctx->buf_off;
 162                 if (i > outl) i=outl;
 163                 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
 164                 ret=i;
 165                 out+=i;
 166                 outl-=i;
 167                 ctx->buf_off+=i;
 168                 if (ctx->buf_len == ctx->buf_off)
 169                         {
 170                         ctx->buf_len=0;
 171                         ctx->buf_off=0;
 172                         }
 173                 }
 174
 175         /* At this point, we have room of outl bytes and an empty
 176          * buffer, so we should read in some more. */
 177
 178         while (outl > 0)
 179                 {
 180                 if (ctx->cont <= 0) break;
 181
 182                 /* read in at offset 8, read the EVP_Cipher
 183                  * documentation about why */
 184                 i=BIO_read(b->next_bio,&(ctx->buf[8]),ENC_BLOCK_SIZE);
 185
 186                 if (i <= 0)
 187                         {
 188                         /* Should be continue next time we are called? */
 189                         if (!BIO_should_retry(b->next_bio))
 190                                 {
 191                                 ctx->cont=i;
 192                                 i=EVP_CipherFinal(&(ctx->cipher),
 193                                         (unsigned char *)ctx->buf,
 194                                         &(ctx->buf_len));
 195                                 ctx->ok=i;
 196                                 ctx->buf_off=0;
 197                                 }
 198                         else
 199                                 ret=(ret == 0)?i:ret;
 200                         break;
 201                         }
 202                 else
 203                         {
 204                         EVP_CipherUpdate(&(ctx->cipher),
 205                                 (unsigned char *)ctx->buf,&ctx->buf_len,
 206                                 (unsigned char *)&(ctx->buf[8]),i);
 207                         ctx->cont=1;
 208                         }
 209
 210                 if (ctx->buf_len <= outl)
 211                         i=ctx->buf_len;
 212                 else
 213                         i=outl;
 214
 215                 if (i <= 0) break;
 216                 memcpy(out,ctx->buf,i);
 217                 ret+=i;
 218                 ctx->buf_off=i;
 219                 outl-=i;
 220                 out+=i;
 221                 }
 222
 223         BIO_clear_retry_flags(b);
 224         BIO_copy_next_retry(b);
 225         return((ret == 0)?ctx->cont:ret);
 226         }
 227
 228 static int enc_write(BIO *b, char *in, int inl)
 229         {
 230         int ret=0,n,i;
 231         BIO_ENC_CTX *ctx;
 232
 233         ctx=(BIO_ENC_CTX *)b->ptr;
 234         ret=inl;
 235
 236         BIO_clear_retry_flags(b);
 237         n=ctx->buf_len-ctx->buf_off;
 238         while (n > 0)
 239                 {
 240                 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 241                 if (i <= 0)
 242                         {
 243                         BIO_copy_next_retry(b);
 244                         return(i);
 245                         }
 246                 ctx->buf_off+=i;
 247                 n-=i;
 248                 }
 249         /* at this point all pending data has been written */
 250
 251         if ((in == NULL) || (inl <= 0)) return(0);
 252
 253         ctx->buf_off=0;
 254         while (inl > 0)
 255                 {
 256                 n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl;
 257                 EVP_CipherUpdate(&(ctx->cipher),
 258                         (unsigned char *)ctx->buf,&ctx->buf_len,
 259                         (unsigned char *)in,n);
 260                 inl-=n;
 261                 in+=n;
 262
 263                 ctx->buf_off=0;
 264                 n=ctx->buf_len;
 265                 while (n > 0)
 266                         {
 267                         i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
 268                         if (i <= 0)
 269                                 {
 270                                 BIO_copy_next_retry(b);
 271                                 return(i);
 272                                 }
 273                         n-=i;
 274                         ctx->buf_off+=i;
 275                         }
 276                 ctx->buf_len=0;
 277                 ctx->buf_off=0;
 278                 }
 279         BIO_copy_next_retry(b);
 280         return(ret);
 281         }
 282
 283 static long enc_ctrl(BIO *b, int cmd, long num, char *ptr)
 284         {
 285         BIO *dbio;
 286         BIO_ENC_CTX *ctx,*dctx;
 287         long ret=1;
 288         int i;
 289         EVP_CIPHER_CTX **c_ctx;
 290
 291         ctx=(BIO_ENC_CTX *)b->ptr;
 292
 293         switch (cmd)
 294                 {
 295         case BIO_CTRL_RESET:
 296                 ctx->ok=1;
 297                 ctx->finished=0;
 298                 EVP_CipherInit(&(ctx->cipher),NULL,NULL,NULL,
 299                         ctx->cipher.encrypt);
 300                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 301                 break;
 302         case BIO_CTRL_EOF:      /* More to read */
 303                 if (ctx->cont <= 0)
 304                         ret=1;
 305                 else
 306                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 307                 break;
 308         case BIO_CTRL_WPENDING:
 309                 ret=ctx->buf_len-ctx->buf_off;
 310                 if (ret <= 0)
 311                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 312                 break;
 313         case BIO_CTRL_PENDING: /* More to read in buffer */
 314                 ret=ctx->buf_len-ctx->buf_off;
 315                 if (ret <= 0)
 316                         ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 317                 break;
 318         case BIO_CTRL_FLUSH:
 319                 /* do a final write */
 320 again:
 321                 while (ctx->buf_len != ctx->buf_off)
 322                         {
 323                         i=enc_write(b,NULL,0);
 324                         if (i < 0)
 325                                 {
 326                                 ret=i;
 327                                 break;
 328                                 }
 329                         }
 330
 331                 if (!ctx->finished)
 332                         {
 333                         ctx->finished=1;
 334                         ctx->buf_off=0;
 335                         ret=EVP_CipherFinal(&(ctx->cipher),
 336                                 (unsigned char *)ctx->buf,
 337                                 &(ctx->buf_len));
 338                         ctx->ok=(int)ret;
 339                         if (ret <= 0) break;
 340
 341                         /* push out the bytes */
 342                         goto again;
 343                         }
 344
 345                 /* Finally flush the underlying BIO */
 346                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 347                 break;
 348         case BIO_C_GET_CIPHER_STATUS:
 349                 ret=(long)ctx->ok;
 350                 break;
 351         case BIO_C_DO_STATE_MACHINE:
 352                 BIO_clear_retry_flags(b);
 353                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 354                 BIO_copy_next_retry(b);
 355                 break;
 356         case BIO_C_GET_CIPHER_CTX:
 357                 c_ctx=(EVP_CIPHER_CTX **)ptr;
 358                 (*c_ctx)= &(ctx->cipher);
 359                 b->init=1;
 360                 break;
 361         case BIO_CTRL_DUP:
 362                 dbio=(BIO *)ptr;
 363                 dctx=(BIO_ENC_CTX *)dbio->ptr;
 364                 memcpy(&(dctx->cipher),&(ctx->cipher),sizeof(ctx->cipher));
 365                 dbio->init=1;
 366                 break;
 367         default:
 368                 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
 369                 break;
 370                 }
 371         return(ret);
 372         }
 373
 374 /*
 375 void BIO_set_cipher_ctx(b,c)
 376 BIO *b;
 377 EVP_CIPHER_ctx *c;
 378         {
 379         if (b == NULL) return;
 380
 381         if ((b->callback != NULL) &&
 382                 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
 383                 return;
 384
 385         b->init=1;
 386         ctx=(BIO_ENC_CTX *)b->ptr;
 387         memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
 388
 389         if (b->callback != NULL)
 390                 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
 391         }
 392 */
 393
 394 void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, unsigned char *k,
 395              unsigned char *i, int e)
 396         {
 397         BIO_ENC_CTX *ctx;
 398
 399         if (b == NULL) return;
 400
 401         if ((b->callback != NULL) &&
 402                 (b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0))
 403                 return;
 404
 405         b->init=1;
 406         ctx=(BIO_ENC_CTX *)b->ptr;
 407         EVP_CipherInit(&(ctx->cipher),c,k,i,e);
 408
 409         if (b->callback != NULL)
 410                 b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L);
 411         }
 412