crypto/evp/evp_enc.c

   1 /* crypto/evp/evp_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 "cryptlib.h"
  61 #include "evp.h"
  62
  63 char *EVP_version="EVP part of SSLeay 0.8.1b 29-Jun-1998";
  64
  65 void EVP_CipherInit(ctx,data,key,iv,enc)
  66 EVP_CIPHER_CTX *ctx;
  67 EVP_CIPHER *data;
  68 unsigned char *key;
  69 unsigned char *iv;
  70 int enc;
  71         {
  72         if (enc)
  73                 EVP_EncryptInit(ctx,data,key,iv);
  74         else
  75                 EVP_DecryptInit(ctx,data,key,iv);
  76         }
  77
  78 void EVP_CipherUpdate(ctx,out,outl,in,inl)
  79 EVP_CIPHER_CTX *ctx;
  80 unsigned char *out;
  81 int *outl;
  82 unsigned char *in;
  83 int inl;
  84         {
  85         if (ctx->encrypt)
  86                 EVP_EncryptUpdate(ctx,out,outl,in,inl);
  87         else    EVP_DecryptUpdate(ctx,out,outl,in,inl);
  88         }
  89
  90 int EVP_CipherFinal(ctx,out,outl)
  91 EVP_CIPHER_CTX *ctx;
  92 unsigned char *out;
  93 int *outl;
  94         {
  95         if (ctx->encrypt)
  96                 {
  97                 EVP_EncryptFinal(ctx,out,outl);
  98                 return(1);
  99                 }
 100         else    return(EVP_DecryptFinal(ctx,out,outl));
 101         }
 102
 103 void EVP_EncryptInit(ctx,cipher,key,iv)
 104 EVP_CIPHER_CTX *ctx;
 105 EVP_CIPHER *cipher;
 106 unsigned char *key;
 107 unsigned char *iv;
 108         {
 109         if (cipher != NULL)
 110                 ctx->cipher=cipher;
 111         ctx->cipher->init(ctx,key,iv,1);
 112         ctx->encrypt=1;
 113         ctx->buf_len=0;
 114         }
 115
 116 void EVP_DecryptInit(ctx,cipher,key,iv)
 117 EVP_CIPHER_CTX *ctx;
 118 EVP_CIPHER *cipher;
 119 unsigned char *key;
 120 unsigned char *iv;
 121         {
 122         if (cipher != NULL)
 123                 ctx->cipher=cipher;
 124         ctx->cipher->init(ctx,key,iv,0);
 125         ctx->encrypt=0;
 126         ctx->buf_len=0;
 127         }
 128
 129
 130 void EVP_EncryptUpdate(ctx,out,outl,in,inl)
 131 EVP_CIPHER_CTX *ctx;
 132 unsigned char *out;
 133 int *outl;
 134 unsigned char *in;
 135 int inl;
 136         {
 137         int i,j,bl;
 138
 139         i=ctx->buf_len;
 140         bl=ctx->cipher->block_size;
 141         *outl=0;
 142         if ((inl == 0) && (i != bl)) return;
 143         if (i != 0)
 144                 {
 145                 if (i+inl < bl)
 146                         {
 147                         memcpy(&(ctx->buf[i]),in,inl);
 148                         ctx->buf_len+=inl;
 149                         return;
 150                         }
 151                 else
 152                         {
 153                         j=bl-i;
 154                         if (j != 0) memcpy(&(ctx->buf[i]),in,j);
 155                         ctx->cipher->do_cipher(ctx,out,ctx->buf,bl);
 156                         inl-=j;
 157                         in+=j;
 158                         out+=bl;
 159                         *outl+=bl;
 160                         }
 161                 }
 162         i=inl%bl; /* how much is left */
 163         inl-=i;
 164         if (inl > 0)
 165                 {
 166                 ctx->cipher->do_cipher(ctx,out,in,inl);
 167                 *outl+=inl;
 168                 }
 169
 170         if (i != 0)
 171                 memcpy(ctx->buf,&(in[inl]),i);
 172         ctx->buf_len=i;
 173         }
 174
 175 void EVP_EncryptFinal(ctx,out,outl)
 176 EVP_CIPHER_CTX *ctx;
 177 unsigned char *out;
 178 int *outl;
 179         {
 180         int i,n,b,bl;
 181
 182         b=ctx->cipher->block_size;
 183         if (b == 1)
 184                 {
 185                 *outl=0;
 186                 return;
 187                 }
 188         bl=ctx->buf_len;
 189         n=b-bl;
 190         for (i=bl; i<b; i++)
 191                 ctx->buf[i]=n;
 192         ctx->cipher->do_cipher(ctx,out,ctx->buf,b);
 193         *outl=b;
 194         }
 195
 196 void EVP_DecryptUpdate(ctx,out,outl,in,inl)
 197 EVP_CIPHER_CTX *ctx;
 198 unsigned char *out;
 199 int *outl;
 200 unsigned char *in;
 201 int inl;
 202         {
 203         int b,bl,n;
 204         int keep_last=0;
 205
 206         *outl=0;
 207         if (inl == 0) return;
 208
 209         b=ctx->cipher->block_size;
 210         if (b > 1)
 211                 {
 212                 /* Is the input a multiple of the block size? */
 213                 bl=ctx->buf_len;
 214                 n=inl+bl;
 215                 if (n%b == 0)
 216                         {
 217                         if (inl < b) /* must be 'just one' buff */
 218                                 {
 219                                 memcpy(&(ctx->buf[bl]),in,inl);
 220                                 ctx->buf_len=b;
 221                                 *outl=0;
 222                                 return;
 223                                 }
 224                         keep_last=1;
 225                         inl-=b; /* don't do the last block */
 226                         }
 227                 }
 228         EVP_EncryptUpdate(ctx,out,outl,in,inl);
 229
 230         /* if we have 'decrypted' a multiple of block size, make sure
 231          * we have a copy of this last block */
 232         if (keep_last)
 233                 {
 234                 memcpy(&(ctx->buf[0]),&(in[inl]),b);
 235 #ifdef DEBUG
 236                 if (ctx->buf_len != 0)
 237                         {
 238                         abort();
 239                         }
 240 #endif
 241                 ctx->buf_len=b;
 242                 }
 243         }
 244
 245 int EVP_DecryptFinal(ctx,out,outl)
 246 EVP_CIPHER_CTX *ctx;
 247 unsigned char *out;
 248 int *outl;
 249         {
 250         int i,b;
 251         int n;
 252
 253         *outl=0;
 254         b=ctx->cipher->block_size;
 255         if (b > 1)
 256                 {
 257                 if (ctx->buf_len != b)
 258                         {
 259                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 260                         return(0);
 261                         }
 262                 EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0);
 263                 if (n != b)
 264                         return(0);
 265                 n=ctx->buf[b-1];
 266                 if (n > b)
 267                         {
 268                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 269                         return(0);
 270                         }
 271                 for (i=0; i<n; i++)
 272                         {
 273                         if (ctx->buf[--b] != n)
 274                                 {
 275                                 EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 276                                 return(0);
 277                                 }
 278                         }
 279                 n=ctx->cipher->block_size-n;
 280                 for (i=0; i<n; i++)
 281                         out[i]=ctx->buf[i];
 282                 *outl=n;
 283                 }
 284         else
 285                 *outl=0;
 286         return(1);
 287         }
 288
 289 void EVP_CIPHER_CTX_cleanup(c)
 290 EVP_CIPHER_CTX *c;
 291         {
 292         if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
 293                 c->cipher->cleanup(c);
 294         memset(c,0,sizeof(EVP_CIPHER_CTX));
 295         }
 296