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         ctx->final_used=0;
 129         ctx->block_mask=ctx->cipher->block_size-1;
 130         return 1;
 131         }
 132
 133 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 134              unsigned char *in, int inl)
 135         {
 136         if (ctx->encrypt)
 137                 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 138         else    return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 139         }
 140
 141 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 142         {
 143         if (ctx->encrypt)
 144                 return EVP_EncryptFinal(ctx,out,outl);
 145         else    return(EVP_DecryptFinal(ctx,out,outl));
 146         }
 147
 148 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 149              unsigned char *key, unsigned char *iv)
 150         {
 151         return EVP_CipherInit(ctx, cipher, key, iv, 1);
 152         }
 153
 154 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 155              unsigned char *key, unsigned char *iv)
 156         {
 157         return EVP_CipherInit(ctx, cipher, key, iv, 0);
 158         }
 159
 160 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 161              unsigned char *in, int inl)
 162         {
 163         int i,j,bl;
 164
 165         if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0)
 166                 {
 167                 if(ctx->cipher->do_cipher(ctx,out,in,inl))
 168                         {
 169                         *outl=inl;
 170                         return 1;
 171                         }
 172                 else
 173                         {
 174                         *outl=0;
 175                         return 0;
 176                         }
 177                 }
 178         i=ctx->buf_len;
 179         bl=ctx->cipher->block_size;
 180         if (i != 0)
 181                 {
 182                 if (i+inl < bl)
 183                         {
 184                         memcpy(&(ctx->buf[i]),in,inl);
 185                         ctx->buf_len+=inl;
 186                         *outl=0;
 187                         return 1;
 188                         }
 189                 else
 190                         {
 191                         j=bl-i;
 192                         memcpy(&(ctx->buf[i]),in,j);
 193                         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 194                         inl-=j;
 195                         in+=j;
 196                         out+=bl;
 197                         *outl=bl;
 198                         }
 199                 }
 200         i=inl&(bl-1);
 201         inl-=i;
 202         if (inl > 0)
 203                 {
 204                 if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 205                 *outl+=inl;
 206                 }
 207
 208         if (i != 0)
 209                 memcpy(ctx->buf,&(in[inl]),i);
 210         ctx->buf_len=i;
 211         return 1;
 212         }
 213
 214 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 215         {
 216         int i,n,b,bl;
 217
 218         b=ctx->cipher->block_size;
 219         if (b == 1)
 220                 {
 221                 *outl=0;
 222                 return 1;
 223                 }
 224         bl=ctx->buf_len;
 225         if (ctx->flags & EVP_CIPH_NO_PADDING)
 226                 {
 227                 if(bl)
 228                         {
 229                         EVPerr(EVP_F_EVP_ENCRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 230                         return 0;
 231                         }
 232                 *outl = 0;
 233                 return 1;
 234                 }
 235         n=b-bl;
 236         for (i=bl; i<b; i++)
 237                 ctx->buf[i]=n;
 238         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
 239         *outl=b;
 240         return 1;
 241         }
 242
 243 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 244              unsigned char *in, int inl)
 245         {
 246         int b;
 247
 248         if (inl == 0)
 249                 {
 250                 *outl=0;
 251                 return 1;
 252                 }
 253
 254         if (ctx->flags & EVP_CIPH_NO_PADDING)
 255                 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 256
 257         b=ctx->cipher->block_size;
 258         if(ctx->final_used)
 259                 {
 260                 memcpy(out,ctx->final,b);
 261                 out+=b;
 262                 }
 263
 264         if(!EVP_EncryptUpdate(ctx,out,outl,in,inl))
 265                 return 0;
 266
 267         /* if we have 'decrypted' a multiple of block size, make sure
 268          * we have a copy of this last block */
 269         if (b > 1 && !ctx->buf_len)
 270                 {
 271                 if(!ctx->final_used)
 272                         {
 273                         *outl-=b;
 274                         ctx->final_used=1;
 275                         }
 276                 memcpy(ctx->final,&out[*outl],b);
 277                 }
 278         else if(ctx->final_used)
 279                 {
 280                 ctx->final_used=0;
 281                 *outl+=b;
 282                 }
 283         return 1;
 284         }
 285
 286 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 287         {
 288         int i,b;
 289         int n;
 290
 291         *outl=0;
 292         b=ctx->cipher->block_size;
 293         if (ctx->flags & EVP_CIPH_NO_PADDING)
 294                 {
 295                 if(ctx->buf_len)
 296                         {
 297                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 298                         return 0;
 299                         }
 300                 *outl = 0;
 301                 return 1;
 302                 }
 303         if (b > 1)
 304                 {
 305                 if (ctx->buf_len || !ctx->final_used)
 306                         {
 307                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 308                         return(0);
 309                         }
 310                 n=ctx->final[b-1];
 311                 if (n > b)
 312                         {
 313                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 314                         return(0);
 315                         }
 316                 for (i=0; i<n; i++)
 317                         {
 318                         if (ctx->final[--b] != n)
 319                                 {
 320                                 EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 321                                 return(0);
 322                                 }
 323                         }
 324                 n=ctx->cipher->block_size-n;
 325                 for (i=0; i<n; i++)
 326                         out[i]=ctx->final[i];
 327                 *outl=n;
 328                 }
 329         else
 330                 *outl=0;
 331         return(1);
 332         }
 333
 334 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 335         {
 336         if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
 337                 {
 338                 if(!c->cipher->cleanup(c)) return 0;
 339                 }
 340         memset(c,0,sizeof(EVP_CIPHER_CTX));
 341         return 1;
 342         }
 343
 344 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 345         {
 346         if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 347                 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 348         if(c->key_len == keylen) return 1;
 349         if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 350                 {
 351                 c->key_len = keylen;
 352                 return 1;
 353                 }
 354         EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 355         return 0;
 356         }
 357
 358 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 359         {
 360         if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
 361         else ctx->flags |= EVP_CIPH_NO_PADDING;
 362         return 1;
 363         }
 364
 365 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 366 {
 367         int ret;
 368         if(!ctx->cipher) {
 369                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 370                 return 0;
 371         }
 372
 373         if(!ctx->cipher->ctrl) {
 374                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 375                 return 0;
 376         }
 377
 378         ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 379         if(ret == -1) {
 380                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 381                 return 0;
 382         }
 383         return ret;
 384 }