crypto/evp/evp_enc.c

   1 /* crypto/evp/evp_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 "cryptlib.h"
  61 #include <openssl/evp.h>
  62 #include <openssl/err.h>
  63 #include "evp_locl.h"
  64
  65 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
  66
  67 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
  68         {
  69         memset(ctx,0,sizeof(EVP_CIPHER_CTX));
  70         /* ctx->cipher=NULL; */
  71         }
  72
  73 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  74              unsigned char *key, unsigned char *iv, int enc)
  75         {
  76         if(enc && (enc != -1)) enc = 1;
  77         if (cipher) {
  78                 ctx->cipher=cipher;
  79                 ctx->key_len = cipher->key_len;
  80                 if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
  81                         if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
  82                                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
  83                                 return 0;
  84                         }
  85                 }
  86         } else if(!ctx->cipher) {
  87                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
  88                 return 0;
  89         }
  90         if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
  91                 switch(EVP_CIPHER_CTX_mode(ctx)) {
  92
  93                         case EVP_CIPH_STREAM_CIPHER:
  94                         case EVP_CIPH_ECB_MODE:
  95                         break;
  96
  97                         case EVP_CIPH_CFB_MODE:
  98                         case EVP_CIPH_OFB_MODE:
  99
 100                         ctx->num = 0;
 101
 102                         case EVP_CIPH_CBC_MODE:
 103
 104                         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 105                         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 106                         break;
 107
 108                         default:
 109                         return 0;
 110                         break;
 111                 }
 112         }
 113
 114         if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 115                 if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
 116         }
 117         if(enc != -1) ctx->encrypt=enc;
 118         ctx->buf_len=0;
 119         return 1;
 120         }
 121
 122 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 123              unsigned char *in, int inl)
 124         {
 125         if (ctx->encrypt)
 126                 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 127         else    return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 128         }
 129
 130 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 131         {
 132         if (ctx->encrypt)
 133                 return EVP_EncryptFinal(ctx,out,outl);
 134         else    return(EVP_DecryptFinal(ctx,out,outl));
 135         }
 136
 137 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 138              unsigned char *key, unsigned char *iv)
 139         {
 140         return EVP_CipherInit(ctx, cipher, key, iv, 1);
 141         }
 142
 143 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 144              unsigned char *key, unsigned char *iv)
 145         {
 146         return EVP_CipherInit(ctx, cipher, key, iv, 0);
 147         }
 148
 149
 150 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 151              unsigned char *in, int inl)
 152         {
 153         int i,j,bl;
 154
 155         i=ctx->buf_len;
 156         bl=ctx->cipher->block_size;
 157         *outl=0;
 158         if ((inl == 0) && (i != bl)) return 1;
 159         if (i != 0)
 160                 {
 161                 if (i+inl < bl)
 162                         {
 163                         memcpy(&(ctx->buf[i]),in,inl);
 164                         ctx->buf_len+=inl;
 165                         return 1;
 166                         }
 167                 else
 168                         {
 169                         j=bl-i;
 170                         if (j != 0) memcpy(&(ctx->buf[i]),in,j);
 171                         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 172                         inl-=j;
 173                         in+=j;
 174                         out+=bl;
 175                         *outl+=bl;
 176                         }
 177                 }
 178         i=inl%bl; /* how much is left */
 179         inl-=i;
 180         if (inl > 0)
 181                 {
 182                 if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 183                 *outl+=inl;
 184                 }
 185
 186         if (i != 0)
 187                 memcpy(ctx->buf,&(in[inl]),i);
 188         ctx->buf_len=i;
 189         return 1;
 190         }
 191
 192 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 193         {
 194         int i,n,b,bl;
 195
 196         b=ctx->cipher->block_size;
 197         if (b == 1)
 198                 {
 199                 *outl=0;
 200                 return 1;
 201                 }
 202         bl=ctx->buf_len;
 203         n=b-bl;
 204         for (i=bl; i<b; i++)
 205                 ctx->buf[i]=n;
 206         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
 207         *outl=b;
 208         return 1;
 209         }
 210
 211 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 212              unsigned char *in, int inl)
 213         {
 214         int b,bl,n;
 215         int keep_last=0;
 216
 217         *outl=0;
 218         if (inl == 0) return 1;
 219
 220         b=ctx->cipher->block_size;
 221         if (b > 1)
 222                 {
 223                 /* Is the input a multiple of the block size? */
 224                 bl=ctx->buf_len;
 225                 n=inl+bl;
 226                 if (n%b == 0)
 227                         {
 228                         if (inl < b) /* must be 'just one' buff */
 229                                 {
 230                                 memcpy(&(ctx->buf[bl]),in,inl);
 231                                 ctx->buf_len=b;
 232                                 *outl=0;
 233                                 return 1;
 234                                 }
 235                         keep_last=1;
 236                         inl-=b; /* don't do the last block */
 237                         }
 238                 }
 239         if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;
 240
 241         /* if we have 'decrypted' a multiple of block size, make sure
 242          * we have a copy of this last block */
 243         if (keep_last)
 244                 {
 245                 memcpy(&(ctx->buf[0]),&(in[inl]),b);
 246 #ifdef DEBUG
 247                 if (ctx->buf_len != 0)
 248                         {
 249                         abort();
 250                         }
 251 #endif
 252                 ctx->buf_len=b;
 253                 }
 254         return 1;
 255         }
 256
 257 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 258         {
 259         int i,b;
 260         int n;
 261
 262         *outl=0;
 263         b=ctx->cipher->block_size;
 264         if (b > 1)
 265                 {
 266                 if (ctx->buf_len != b)
 267                         {
 268                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 269                         return(0);
 270                         }
 271                 if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
 272                 if (n != b)
 273                         return(0);
 274                 n=ctx->buf[b-1];
 275                 if (n > b)
 276                         {
 277                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 278                         return(0);
 279                         }
 280                 for (i=0; i<n; i++)
 281                         {
 282                         if (ctx->buf[--b] != n)
 283                                 {
 284                                 EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 285                                 return(0);
 286                                 }
 287                         }
 288                 n=ctx->cipher->block_size-n;
 289                 for (i=0; i<n; i++)
 290                         out[i]=ctx->buf[i];
 291                 *outl=n;
 292                 }
 293         else
 294                 *outl=0;
 295         return(1);
 296         }
 297
 298 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 299         {
 300         if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
 301                 {
 302                 if(!c->cipher->cleanup(c)) return 0;
 303                 }
 304         memset(c,0,sizeof(EVP_CIPHER_CTX));
 305         return 1;
 306         }
 307
 308 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 309         {
 310         if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 311                 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 312         if(c->key_len == keylen) return 1;
 313         if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 314                 {
 315                 c->key_len = keylen;
 316                 return 1;
 317                 }
 318         EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 319         return 0;
 320         }
 321
 322 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 323 {
 324         int ret;
 325         if(!ctx->cipher) {
 326                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 327                 return 0;
 328         }
 329
 330         if(!ctx->cipher->ctrl) {
 331                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 332                 return 0;
 333         }
 334
 335         ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 336         if(ret == -1) {
 337                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 338                 return 0;
 339         }
 340         return ret;
 341 }