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 #include <assert.h>
  66
  67 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
  68
  69 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
  70         {
  71         memset(ctx,0,sizeof(EVP_CIPHER_CTX));
  72         /* ctx->cipher=NULL; */
  73         }
  74
  75 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  76              unsigned char *key, unsigned char *iv, int enc)
  77         {
  78         if(enc && (enc != -1)) enc = 1;
  79         if (cipher) {
  80                 ctx->cipher=cipher;
  81                 ctx->key_len = cipher->key_len;
  82                 ctx->flags = 0;
  83                 if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
  84                         if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
  85                                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
  86                                 return 0;
  87                         }
  88                 }
  89         } else if(!ctx->cipher) {
  90                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
  91                 return 0;
  92         }
  93
  94         /* we assume block size is a power of 2 in *cryptUpdate */
  95         assert(ctx->cipher->block_size == 1
  96                || ctx->cipher->block_size == 8
  97                || ctx->cipher->block_size == 16);
  98
  99         if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
 100                 switch(EVP_CIPHER_CTX_mode(ctx)) {
 101
 102                         case EVP_CIPH_STREAM_CIPHER:
 103                         case EVP_CIPH_ECB_MODE:
 104                         break;
 105
 106                         case EVP_CIPH_CFB_MODE:
 107                         case EVP_CIPH_OFB_MODE:
 108
 109                         ctx->num = 0;
 110
 111                         case EVP_CIPH_CBC_MODE:
 112
 113                         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 114                         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 115                         break;
 116
 117                         default:
 118                         return 0;
 119                         break;
 120                 }
 121         }
 122
 123         if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 124                 if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
 125         }
 126         if(enc != -1) ctx->encrypt=enc;
 127         ctx->buf_len=0;
 128         return 1;
 129         }
 130
 131 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 132              unsigned char *in, int inl)
 133         {
 134         if (ctx->encrypt)
 135                 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 136         else    return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 137         }
 138
 139 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 140         {
 141         if (ctx->encrypt)
 142                 return EVP_EncryptFinal(ctx,out,outl);
 143         else    return(EVP_DecryptFinal(ctx,out,outl));
 144         }
 145
 146 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 147              unsigned char *key, unsigned char *iv)
 148         {
 149         return EVP_CipherInit(ctx, cipher, key, iv, 1);
 150         }
 151
 152 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 153              unsigned char *key, unsigned char *iv)
 154         {
 155         return EVP_CipherInit(ctx, cipher, key, iv, 0);
 156         }
 157
 158 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 159              unsigned char *in, int inl)
 160         {
 161         int i,j,bl;
 162
 163         i=ctx->buf_len;
 164         bl=ctx->cipher->block_size;
 165         if ((inl == 0) && (i != bl))
 166                 {
 167                 *outl=0;
 168                 return 1;
 169                 }
 170         if(i == 0 && (inl&(bl-1)) == 0)
 171                 {
 172                 if(ctx->cipher->do_cipher(ctx,out,in,inl))
 173                         {
 174                         *outl=inl;
 175                         return 1;
 176                         }
 177                 else
 178                         {
 179                         *outl=0;
 180                         return 0;
 181                         }
 182                 }
 183         *outl=0;
 184         if (i != 0)
 185                 {
 186                 if (i+inl < bl)
 187                         {
 188                         memcpy(&(ctx->buf[i]),in,inl);
 189                         ctx->buf_len+=inl;
 190                         return 1;
 191                         }
 192                 else
 193                         {
 194                         j=bl-i;
 195                         if (j != 0) memcpy(&(ctx->buf[i]),in,j);
 196                         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 197                         inl-=j;
 198                         in+=j;
 199                         out+=bl;
 200                         *outl+=bl;
 201                         }
 202                 }
 203         i=inl&(bl-1);
 204         inl-=i;
 205         if (inl > 0)
 206                 {
 207                 if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 208                 *outl+=inl;
 209                 }
 210
 211         if (i != 0)
 212                 memcpy(ctx->buf,&(in[inl]),i);
 213         ctx->buf_len=i;
 214         return 1;
 215         }
 216
 217 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 218         {
 219         int i,n,b,bl;
 220
 221         b=ctx->cipher->block_size;
 222         if (b == 1)
 223                 {
 224                 *outl=0;
 225                 return 1;
 226                 }
 227         bl=ctx->buf_len;
 228         if (ctx->flags & EVP_CIPH_NO_PADDING)
 229                 {
 230                 if(bl)
 231                         {
 232                         EVPerr(EVP_F_EVP_ENCRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 233                         return 0;
 234                         }
 235                 *outl = 0;
 236                 return 1;
 237                 }
 238         n=b-bl;
 239         for (i=bl; i<b; i++)
 240                 ctx->buf[i]=n;
 241         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
 242         *outl=b;
 243         return 1;
 244         }
 245
 246 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 247              unsigned char *in, int inl)
 248         {
 249         int b,bl,n;
 250         int keep_last=0;
 251
 252         *outl=0;
 253         if (inl == 0) return 1;
 254
 255         if (ctx->flags & EVP_CIPH_NO_PADDING)
 256                 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 257
 258         b=ctx->cipher->block_size;
 259         if (b > 1)
 260                 {
 261                 /* Is the input a multiple of the block size? */
 262                 bl=ctx->buf_len;
 263                 n=inl+bl;
 264                 if (n%b == 0)
 265                         {
 266                         if (inl < b) /* must be 'just one' buff */
 267                                 {
 268                                 memcpy(&(ctx->buf[bl]),in,inl);
 269                                 ctx->buf_len=b;
 270                                 *outl=0;
 271                                 return 1;
 272                                 }
 273                         keep_last=1;
 274                         inl-=b; /* don't do the last block */
 275                         }
 276                 }
 277         if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;
 278
 279         /* if we have 'decrypted' a multiple of block size, make sure
 280          * we have a copy of this last block */
 281         if (keep_last)
 282                 {
 283                 memcpy(&(ctx->buf[0]),&(in[inl]),b);
 284 #ifdef DEBUG
 285                 if (ctx->buf_len != 0)
 286                         {
 287                         abort();
 288                         }
 289 #endif
 290                 ctx->buf_len=b;
 291                 }
 292         return 1;
 293         }
 294
 295 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 296         {
 297         int i,b;
 298         int n;
 299
 300         *outl=0;
 301         b=ctx->cipher->block_size;
 302         if (ctx->flags & EVP_CIPH_NO_PADDING)
 303                 {
 304                 if(ctx->buf_len)
 305                         {
 306                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 307                         return 0;
 308                         }
 309                 *outl = 0;
 310                 return 1;
 311                 }
 312         if (b > 1)
 313                 {
 314                 if (ctx->buf_len != b)
 315                         {
 316                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 317                         return(0);
 318                         }
 319                 if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
 320                 if (n != b)
 321                         return(0);
 322                 n=ctx->buf[b-1];
 323                 if (n > b)
 324                         {
 325                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 326                         return(0);
 327                         }
 328                 for (i=0; i<n; i++)
 329                         {
 330                         if (ctx->buf[--b] != n)
 331                                 {
 332                                 EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 333                                 return(0);
 334                                 }
 335                         }
 336                 n=ctx->cipher->block_size-n;
 337                 for (i=0; i<n; i++)
 338                         out[i]=ctx->buf[i];
 339                 *outl=n;
 340                 }
 341         else
 342                 *outl=0;
 343         return(1);
 344         }
 345
 346 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 347         {
 348         if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
 349                 {
 350                 if(!c->cipher->cleanup(c)) return 0;
 351                 }
 352         memset(c,0,sizeof(EVP_CIPHER_CTX));
 353         return 1;
 354         }
 355
 356 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 357         {
 358         if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 359                 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 360         if(c->key_len == keylen) return 1;
 361         if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 362                 {
 363                 c->key_len = keylen;
 364                 return 1;
 365                 }
 366         EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 367         return 0;
 368         }
 369
 370 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 371         {
 372         if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
 373         else ctx->flags |= EVP_CIPH_NO_PADDING;
 374         return 1;
 375         }
 376
 377 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 378 {
 379         int ret;
 380         if(!ctx->cipher) {
 381                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 382                 return 0;
 383         }
 384
 385         if(!ctx->cipher->ctrl) {
 386                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 387                 return 0;
 388         }
 389
 390         ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 391         if(ret == -1) {
 392                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 393                 return 0;
 394         }
 395         return ret;
 396 }