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 #ifndef OPENSSL_NO_ENGINE
  64 #include <openssl/engine.h>
  65 #endif
  66 #include "evp_locl.h"
  67
  68 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
  69
  70 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
  71         {
  72         memset(ctx,0,sizeof(EVP_CIPHER_CTX));
  73         /* ctx->cipher=NULL; */
  74         }
  75
  76
  77 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  78              const unsigned char *key, const unsigned char *iv, int enc)
  79         {
  80         if (cipher)
  81                 EVP_CIPHER_CTX_init(ctx);
  82         return EVP_CipherInit_ex(ctx,cipher,NULL,key,iv,enc);
  83         }
  84
  85 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
  86              const unsigned char *key, const unsigned char *iv, int enc)
  87         {
  88         if (enc == -1)
  89                 enc = ctx->encrypt;
  90         else
  91                 {
  92                 if (enc)
  93                         enc = 1;
  94                 ctx->encrypt = enc;
  95                 }
  96 #ifndef OPENSSL_NO_ENGINE
  97         /* Whether it's nice or not, "Inits" can be used on "Final"'d contexts
  98          * so this context may already have an ENGINE! Try to avoid releasing
  99          * the previous handle, re-querying for an ENGINE, and having a
 100          * reinitialisation, when it may all be unecessary. */
 101         if (ctx->engine && ctx->cipher && (!cipher ||
 102                         (cipher && (cipher->nid == ctx->cipher->nid))))
 103                 goto skip_to_init;
 104 #endif
 105         if (cipher)
 106                 {
 107                 /* Ensure a context left lying around from last time is cleared
 108                  * (the previous check attempted to avoid this if the same
 109                  * ENGINE and EVP_CIPHER could be used). */
 110                 EVP_CIPHER_CTX_cleanup(ctx);
 111
 112                 /* Restore encrypt field: it is zeroed by cleanup */
 113                 ctx->encrypt = enc;
 114 #ifndef OPENSSL_NO_ENGINE
 115                 if(impl)
 116                         {
 117                         if (!ENGINE_init(impl))
 118                                 {
 119                                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
 120                                 return 0;
 121                                 }
 122                         }
 123                 else
 124                         /* Ask if an ENGINE is reserved for this job */
 125                         impl = ENGINE_get_cipher_engine(cipher->nid);
 126                 if(impl)
 127                         {
 128                         /* There's an ENGINE for this job ... (apparently) */
 129                         const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 130                         if(!c)
 131                                 {
 132                                 /* One positive side-effect of US's export
 133                                  * control history, is that we should at least
 134                                  * be able to avoid using US mispellings of
 135                                  * "initialisation"? */
 136                                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
 137                                 return 0;
 138                                 }
 139                         /* We'll use the ENGINE's private cipher definition */
 140                         cipher = c;
 141                         /* Store the ENGINE functional reference so we know
 142                          * 'cipher' came from an ENGINE and we need to release
 143                          * it when done. */
 144                         ctx->engine = impl;
 145                         }
 146                 else
 147                         ctx->engine = NULL;
 148 #endif
 149
 150                 ctx->cipher=cipher;
 151                 ctx->cipher_data=OPENSSL_malloc(ctx->cipher->ctx_size);
 152                 ctx->key_len = cipher->key_len;
 153                 ctx->flags = 0;
 154                 if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT)
 155                         {
 156                         if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL))
 157                                 {
 158                                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
 159                                 return 0;
 160                                 }
 161                         }
 162                 }
 163         else if(!ctx->cipher)
 164                 {
 165                 EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
 166                 return 0;
 167                 }
 168 #ifndef OPENSSL_NO_ENGINE
 169 skip_to_init:
 170 #endif
 171         /* we assume block size is a power of 2 in *cryptUpdate */
 172         OPENSSL_assert(ctx->cipher->block_size == 1
 173             || ctx->cipher->block_size == 8
 174             || ctx->cipher->block_size == 16);
 175
 176         if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
 177                 switch(EVP_CIPHER_CTX_mode(ctx)) {
 178
 179                         case EVP_CIPH_STREAM_CIPHER:
 180                         case EVP_CIPH_ECB_MODE:
 181                         break;
 182
 183                         case EVP_CIPH_CFB_MODE:
 184                         case EVP_CIPH_OFB_MODE:
 185
 186                         ctx->num = 0;
 187
 188                         case EVP_CIPH_CBC_MODE:
 189
 190                         OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 191                                         (int)sizeof(ctx->iv));
 192                         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 193                         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 194                         break;
 195
 196                         default:
 197                         return 0;
 198                         break;
 199                 }
 200         }
 201
 202         if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 203                 if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
 204         }
 205         ctx->buf_len=0;
 206         ctx->final_used=0;
 207         ctx->block_mask=ctx->cipher->block_size-1;
 208         return 1;
 209         }
 210
 211 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 212              const unsigned char *in, int inl)
 213         {
 214         if (ctx->encrypt)
 215                 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 216         else    return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 217         }
 218
 219 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 220         {
 221         if (ctx->encrypt)
 222                 return EVP_EncryptFinal_ex(ctx,out,outl);
 223         else    return EVP_DecryptFinal_ex(ctx,out,outl);
 224         }
 225
 226 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 227         {
 228         if (ctx->encrypt)
 229                 return EVP_EncryptFinal(ctx,out,outl);
 230         else    return EVP_DecryptFinal(ctx,out,outl);
 231         }
 232
 233 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 234              const unsigned char *key, const unsigned char *iv)
 235         {
 236         return EVP_CipherInit(ctx, cipher, key, iv, 1);
 237         }
 238
 239 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx,const EVP_CIPHER *cipher, ENGINE *impl,
 240                 const unsigned char *key, const unsigned char *iv)
 241         {
 242         return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 243         }
 244
 245 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 246              const unsigned char *key, const unsigned char *iv)
 247         {
 248         return EVP_CipherInit(ctx, cipher, key, iv, 0);
 249         }
 250
 251 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
 252              const unsigned char *key, const unsigned char *iv)
 253         {
 254         return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 255         }
 256
 257 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 258              const unsigned char *in, int inl)
 259         {
 260         int i,j,bl;
 261
 262         OPENSSL_assert(inl > 0);
 263         if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0)
 264                 {
 265                 if(ctx->cipher->do_cipher(ctx,out,in,inl))
 266                         {
 267                         *outl=inl;
 268                         return 1;
 269                         }
 270                 else
 271                         {
 272                         *outl=0;
 273                         return 0;
 274                         }
 275                 }
 276         i=ctx->buf_len;
 277         bl=ctx->cipher->block_size;
 278         OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 279         if (i != 0)
 280                 {
 281                 if (i+inl < bl)
 282                         {
 283                         memcpy(&(ctx->buf[i]),in,inl);
 284                         ctx->buf_len+=inl;
 285                         *outl=0;
 286                         return 1;
 287                         }
 288                 else
 289                         {
 290                         j=bl-i;
 291                         memcpy(&(ctx->buf[i]),in,j);
 292                         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 293                         inl-=j;
 294                         in+=j;
 295                         out+=bl;
 296                         *outl=bl;
 297                         }
 298                 }
 299         else
 300                 *outl = 0;
 301         i=inl&(bl-1);
 302         inl-=i;
 303         if (inl > 0)
 304                 {
 305                 if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 306                 *outl+=inl;
 307                 }
 308
 309         if (i != 0)
 310                 memcpy(ctx->buf,&(in[inl]),i);
 311         ctx->buf_len=i;
 312         return 1;
 313         }
 314
 315 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 316         {
 317         int ret;
 318         ret = EVP_EncryptFinal_ex(ctx, out, outl);
 319         return ret;
 320         }
 321
 322 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 323         {
 324         int n,ret;
 325         unsigned int i, b, bl;
 326
 327         b=ctx->cipher->block_size;
 328         OPENSSL_assert(b <= sizeof ctx->buf);
 329         if (b == 1)
 330                 {
 331                 *outl=0;
 332                 return 1;
 333                 }
 334         bl=ctx->buf_len;
 335         if (ctx->flags & EVP_CIPH_NO_PADDING)
 336                 {
 337                 if(bl)
 338                         {
 339                         EVPerr(EVP_F_EVP_ENCRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 340                         return 0;
 341                         }
 342                 *outl = 0;
 343                 return 1;
 344                 }
 345
 346         n=b-bl;
 347         for (i=bl; i<b; i++)
 348                 ctx->buf[i]=n;
 349         ret=ctx->cipher->do_cipher(ctx,out,ctx->buf,b);
 350
 351
 352         if(ret)
 353                 *outl=b;
 354
 355         return ret;
 356         }
 357
 358 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 359              const unsigned char *in, int inl)
 360         {
 361         int fix_len;
 362         unsigned int b;
 363
 364         if (inl == 0)
 365                 {
 366                 *outl=0;
 367                 return 1;
 368                 }
 369
 370         if (ctx->flags & EVP_CIPH_NO_PADDING)
 371                 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 372
 373         b=ctx->cipher->block_size;
 374         OPENSSL_assert(b <= sizeof ctx->final);
 375
 376         if(ctx->final_used)
 377                 {
 378                 memcpy(out,ctx->final,b);
 379                 out+=b;
 380                 fix_len = 1;
 381                 }
 382         else
 383                 fix_len = 0;
 384
 385
 386         if(!EVP_EncryptUpdate(ctx,out,outl,in,inl))
 387                 return 0;
 388
 389         /* if we have 'decrypted' a multiple of block size, make sure
 390          * we have a copy of this last block */
 391         if (b > 1 && !ctx->buf_len)
 392                 {
 393                 *outl-=b;
 394                 ctx->final_used=1;
 395                 memcpy(ctx->final,&out[*outl],b);
 396                 }
 397         else
 398                 ctx->final_used = 0;
 399
 400         if (fix_len)
 401                 *outl += b;
 402
 403         return 1;
 404         }
 405
 406 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 407         {
 408         int ret;
 409         ret = EVP_DecryptFinal_ex(ctx, out, outl);
 410         return ret;
 411         }
 412
 413 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 414         {
 415         int i,n;
 416         unsigned int b;
 417
 418         *outl=0;
 419         b=ctx->cipher->block_size;
 420         if (ctx->flags & EVP_CIPH_NO_PADDING)
 421                 {
 422                 if(ctx->buf_len)
 423                         {
 424                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 425                         return 0;
 426                         }
 427                 *outl = 0;
 428                 return 1;
 429                 }
 430         if (b > 1)
 431                 {
 432                 if (ctx->buf_len || !ctx->final_used)
 433                         {
 434                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 435                         return(0);
 436                         }
 437                 OPENSSL_assert(b <= sizeof ctx->final);
 438                 n=ctx->final[b-1];
 439                 if (n > (int)b)
 440                         {
 441                         EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 442                         return(0);
 443                         }
 444                 for (i=0; i<n; i++)
 445                         {
 446                         if (ctx->final[--b] != n)
 447                                 {
 448                                 EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 449                                 return(0);
 450                                 }
 451                         }
 452                 n=ctx->cipher->block_size-n;
 453                 for (i=0; i<n; i++)
 454                         out[i]=ctx->final[i];
 455                 *outl=n;
 456                 }
 457         else
 458                 *outl=0;
 459         return(1);
 460         }
 461
 462 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 463         {
 464         if (c->cipher != NULL)
 465                 {
 466                 if(c->cipher->cleanup && !c->cipher->cleanup(c))
 467                         return 0;
 468                 /* Cleanse cipher context data */
 469                 if (c->cipher_data)
 470                         OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
 471                 }
 472         if (c->cipher_data)
 473                 OPENSSL_free(c->cipher_data);
 474 #ifndef OPENSSL_NO_ENGINE
 475         if (c->engine)
 476                 /* The EVP_CIPHER we used belongs to an ENGINE, release the
 477                  * functional reference we held for this reason. */
 478                 ENGINE_finish(c->engine);
 479 #endif
 480         memset(c,0,sizeof(EVP_CIPHER_CTX));
 481         return 1;
 482         }
 483
 484 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 485         {
 486         if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 487                 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 488         if(c->key_len == keylen) return 1;
 489         if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 490                 {
 491                 c->key_len = keylen;
 492                 return 1;
 493                 }
 494         EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 495         return 0;
 496         }
 497
 498 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 499         {
 500         if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
 501         else ctx->flags |= EVP_CIPH_NO_PADDING;
 502         return 1;
 503         }
 504
 505 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 506 {
 507         int ret;
 508         if(!ctx->cipher) {
 509                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 510                 return 0;
 511         }
 512
 513         if(!ctx->cipher->ctrl) {
 514                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 515                 return 0;
 516         }
 517
 518         ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 519         if(ret == -1) {
 520                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 521                 return 0;
 522         }
 523         return ret;
 524 }