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 <openssl/rand.h>
  64 #ifndef OPENSSL_NO_ENGINE
  65 #include <openssl/engine.h>
  66 #endif
  67 #include "evp_locl.h"
  68
  69 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
  70
  71 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
  72         {
  73         memset(ctx,0,sizeof(EVP_CIPHER_CTX));
  74         /* ctx->cipher=NULL; */
  75         }
  76
  77 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
  78         {
  79         EVP_CIPHER_CTX *ctx=OPENSSL_malloc(sizeof *ctx);
  80         if (ctx)
  81                 EVP_CIPHER_CTX_init(ctx);
  82         return ctx;
  83         }
  84
  85 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  86              const unsigned char *key, const unsigned char *iv, int enc)
  87         {
  88         if (cipher)
  89                 EVP_CIPHER_CTX_init(ctx);
  90         return EVP_CipherInit_ex(ctx,cipher,NULL,key,iv,enc);
  91         }
  92
  93 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
  94              const unsigned char *key, const unsigned char *iv, int enc)
  95         {
  96         if (enc == -1)
  97                 enc = ctx->encrypt;
  98         else
  99                 {
 100                 if (enc)
 101                         enc = 1;
 102                 ctx->encrypt = enc;
 103                 }
 104 #ifndef OPENSSL_NO_ENGINE
 105         /* Whether it's nice or not, "Inits" can be used on "Final"'d contexts
 106          * so this context may already have an ENGINE! Try to avoid releasing
 107          * the previous handle, re-querying for an ENGINE, and having a
 108          * reinitialisation, when it may all be unecessary. */
 109         if (ctx->engine && ctx->cipher && (!cipher ||
 110                         (cipher && (cipher->nid == ctx->cipher->nid))))
 111                 goto skip_to_init;
 112 #endif
 113         if (cipher)
 114                 {
 115                 /* Ensure a context left lying around from last time is cleared
 116                  * (the previous check attempted to avoid this if the same
 117                  * ENGINE and EVP_CIPHER could be used). */
 118                 EVP_CIPHER_CTX_cleanup(ctx);
 119
 120                 /* Restore encrypt field: it is zeroed by cleanup */
 121                 ctx->encrypt = enc;
 122 #ifndef OPENSSL_NO_ENGINE
 123                 if(impl)
 124                         {
 125                         if (!ENGINE_init(impl))
 126                                 {
 127                                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 128                                 return 0;
 129                                 }
 130                         }
 131                 else
 132                         /* Ask if an ENGINE is reserved for this job */
 133                         impl = ENGINE_get_cipher_engine(cipher->nid);
 134                 if(impl)
 135                         {
 136                         /* There's an ENGINE for this job ... (apparently) */
 137                         const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 138                         if(!c)
 139                                 {
 140                                 /* One positive side-effect of US's export
 141                                  * control history, is that we should at least
 142                                  * be able to avoid using US mispellings of
 143                                  * "initialisation"? */
 144                                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 145                                 return 0;
 146                                 }
 147                         /* We'll use the ENGINE's private cipher definition */
 148                         cipher = c;
 149                         /* Store the ENGINE functional reference so we know
 150                          * 'cipher' came from an ENGINE and we need to release
 151                          * it when done. */
 152                         ctx->engine = impl;
 153                         }
 154                 else
 155                         ctx->engine = NULL;
 156 #endif
 157
 158                 ctx->cipher=cipher;
 159                 if (ctx->cipher->ctx_size)
 160                         {
 161                         ctx->cipher_data=OPENSSL_malloc(ctx->cipher->ctx_size);
 162                         if (!ctx->cipher_data)
 163                                 {
 164                                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 165                                 return 0;
 166                                 }
 167                         }
 168                 else
 169                         {
 170                         ctx->cipher_data = NULL;
 171                         }
 172                 ctx->key_len = cipher->key_len;
 173                 ctx->flags = 0;
 174                 if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT)
 175                         {
 176                         if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL))
 177                                 {
 178                                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 179                                 return 0;
 180                                 }
 181                         }
 182                 }
 183         else if(!ctx->cipher)
 184                 {
 185                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
 186                 return 0;
 187                 }
 188 #ifndef OPENSSL_NO_ENGINE
 189 skip_to_init:
 190 #endif
 191         /* we assume block size is a power of 2 in *cryptUpdate */
 192         OPENSSL_assert(ctx->cipher->block_size == 1
 193             || ctx->cipher->block_size == 8
 194             || ctx->cipher->block_size == 16);
 195
 196         if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
 197                 switch(EVP_CIPHER_CTX_mode(ctx)) {
 198
 199                         case EVP_CIPH_STREAM_CIPHER:
 200                         case EVP_CIPH_ECB_MODE:
 201                         break;
 202
 203                         case EVP_CIPH_CFB_MODE:
 204                         case EVP_CIPH_OFB_MODE:
 205
 206                         ctx->num = 0;
 207
 208                         case EVP_CIPH_CBC_MODE:
 209
 210                         OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 211                                         (int)sizeof(ctx->iv));
 212                         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 213                         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 214                         break;
 215
 216                         default:
 217                         return 0;
 218                         break;
 219                 }
 220         }
 221
 222         if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 223                 if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
 224         }
 225         ctx->buf_len=0;
 226         ctx->final_used=0;
 227         ctx->block_mask=ctx->cipher->block_size-1;
 228         return 1;
 229         }
 230
 231 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 232              const unsigned char *in, int inl)
 233         {
 234         if (ctx->encrypt)
 235                 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 236         else    return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 237         }
 238
 239 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 240         {
 241         if (ctx->encrypt)
 242                 return EVP_EncryptFinal_ex(ctx,out,outl);
 243         else    return EVP_DecryptFinal_ex(ctx,out,outl);
 244         }
 245
 246 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 247         {
 248         if (ctx->encrypt)
 249                 return EVP_EncryptFinal(ctx,out,outl);
 250         else    return EVP_DecryptFinal(ctx,out,outl);
 251         }
 252
 253 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 254              const unsigned char *key, const unsigned char *iv)
 255         {
 256         return EVP_CipherInit(ctx, cipher, key, iv, 1);
 257         }
 258
 259 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx,const EVP_CIPHER *cipher, ENGINE *impl,
 260                 const unsigned char *key, const unsigned char *iv)
 261         {
 262         return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 263         }
 264
 265 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 266              const unsigned char *key, const unsigned char *iv)
 267         {
 268         return EVP_CipherInit(ctx, cipher, key, iv, 0);
 269         }
 270
 271 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
 272              const unsigned char *key, const unsigned char *iv)
 273         {
 274         return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 275         }
 276
 277 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 278              const unsigned char *in, int inl)
 279         {
 280         int i,j,bl;
 281
 282         OPENSSL_assert(inl > 0);
 283         if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0)
 284                 {
 285                 if(ctx->cipher->do_cipher(ctx,out,in,inl))
 286                         {
 287                         *outl=inl;
 288                         return 1;
 289                         }
 290                 else
 291                         {
 292                         *outl=0;
 293                         return 0;
 294                         }
 295                 }
 296         i=ctx->buf_len;
 297         bl=ctx->cipher->block_size;
 298         OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 299         if (i != 0)
 300                 {
 301                 if (i+inl < bl)
 302                         {
 303                         memcpy(&(ctx->buf[i]),in,inl);
 304                         ctx->buf_len+=inl;
 305                         *outl=0;
 306                         return 1;
 307                         }
 308                 else
 309                         {
 310                         j=bl-i;
 311                         memcpy(&(ctx->buf[i]),in,j);
 312                         if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 313                         inl-=j;
 314                         in+=j;
 315                         out+=bl;
 316                         *outl=bl;
 317                         }
 318                 }
 319         else
 320                 *outl = 0;
 321         i=inl&(bl-1);
 322         inl-=i;
 323         if (inl > 0)
 324                 {
 325                 if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 326                 *outl+=inl;
 327                 }
 328
 329         if (i != 0)
 330                 memcpy(ctx->buf,&(in[inl]),i);
 331         ctx->buf_len=i;
 332         return 1;
 333         }
 334
 335 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 336         {
 337         int ret;
 338         ret = EVP_EncryptFinal_ex(ctx, out, outl);
 339         return ret;
 340         }
 341
 342 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 343         {
 344         int n,ret;
 345         unsigned int i, b, bl;
 346
 347         b=ctx->cipher->block_size;
 348         OPENSSL_assert(b <= sizeof ctx->buf);
 349         if (b == 1)
 350                 {
 351                 *outl=0;
 352                 return 1;
 353                 }
 354         bl=ctx->buf_len;
 355         if (ctx->flags & EVP_CIPH_NO_PADDING)
 356                 {
 357                 if(bl)
 358                         {
 359                         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 360                         return 0;
 361                         }
 362                 *outl = 0;
 363                 return 1;
 364                 }
 365
 366         n=b-bl;
 367         for (i=bl; i<b; i++)
 368                 ctx->buf[i]=n;
 369         ret=ctx->cipher->do_cipher(ctx,out,ctx->buf,b);
 370
 371
 372         if(ret)
 373                 *outl=b;
 374
 375         return ret;
 376         }
 377
 378 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 379              const unsigned char *in, int inl)
 380         {
 381         int fix_len;
 382         unsigned int b;
 383
 384         if (inl == 0)
 385                 {
 386                 *outl=0;
 387                 return 1;
 388                 }
 389
 390         if (ctx->flags & EVP_CIPH_NO_PADDING)
 391                 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 392
 393         b=ctx->cipher->block_size;
 394         OPENSSL_assert(b <= sizeof ctx->final);
 395
 396         if(ctx->final_used)
 397                 {
 398                 memcpy(out,ctx->final,b);
 399                 out+=b;
 400                 fix_len = 1;
 401                 }
 402         else
 403                 fix_len = 0;
 404
 405
 406         if(!EVP_EncryptUpdate(ctx,out,outl,in,inl))
 407                 return 0;
 408
 409         /* if we have 'decrypted' a multiple of block size, make sure
 410          * we have a copy of this last block */
 411         if (b > 1 && !ctx->buf_len)
 412                 {
 413                 *outl-=b;
 414                 ctx->final_used=1;
 415                 memcpy(ctx->final,&out[*outl],b);
 416                 }
 417         else
 418                 ctx->final_used = 0;
 419
 420         if (fix_len)
 421                 *outl += b;
 422
 423         return 1;
 424         }
 425
 426 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 427         {
 428         int ret;
 429         ret = EVP_DecryptFinal_ex(ctx, out, outl);
 430         return ret;
 431         }
 432
 433 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 434         {
 435         int i,n;
 436         unsigned int b;
 437
 438         *outl=0;
 439         b=ctx->cipher->block_size;
 440         if (ctx->flags & EVP_CIPH_NO_PADDING)
 441                 {
 442                 if(ctx->buf_len)
 443                         {
 444                         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 445                         return 0;
 446                         }
 447                 *outl = 0;
 448                 return 1;
 449                 }
 450         if (b > 1)
 451                 {
 452                 if (ctx->buf_len || !ctx->final_used)
 453                         {
 454                         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 455                         return(0);
 456                         }
 457                 OPENSSL_assert(b <= sizeof ctx->final);
 458                 n=ctx->final[b-1];
 459                 if (n == 0 || n > (int)b)
 460                         {
 461                         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_BAD_DECRYPT);
 462                         return(0);
 463                         }
 464                 for (i=0; i<n; i++)
 465                         {
 466                         if (ctx->final[--b] != n)
 467                                 {
 468                                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_BAD_DECRYPT);
 469                                 return(0);
 470                                 }
 471                         }
 472                 n=ctx->cipher->block_size-n;
 473                 for (i=0; i<n; i++)
 474                         out[i]=ctx->final[i];
 475                 *outl=n;
 476                 }
 477         else
 478                 *outl=0;
 479         return(1);
 480         }
 481
 482 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
 483         {
 484         if (ctx)
 485                 {
 486                 EVP_CIPHER_CTX_cleanup(ctx);
 487                 OPENSSL_free(ctx);
 488                 }
 489         }
 490
 491 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 492         {
 493         if (c->cipher != NULL)
 494                 {
 495                 if(c->cipher->cleanup && !c->cipher->cleanup(c))
 496                         return 0;
 497                 /* Cleanse cipher context data */
 498                 if (c->cipher_data)
 499                         OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
 500                 }
 501         if (c->cipher_data)
 502                 OPENSSL_free(c->cipher_data);
 503 #ifndef OPENSSL_NO_ENGINE
 504         if (c->engine)
 505                 /* The EVP_CIPHER we used belongs to an ENGINE, release the
 506                  * functional reference we held for this reason. */
 507                 ENGINE_finish(c->engine);
 508 #endif
 509         memset(c,0,sizeof(EVP_CIPHER_CTX));
 510         return 1;
 511         }
 512
 513 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 514         {
 515         if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 516                 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 517         if(c->key_len == keylen) return 1;
 518         if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 519                 {
 520                 c->key_len = keylen;
 521                 return 1;
 522                 }
 523         EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 524         return 0;
 525         }
 526
 527 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 528         {
 529         if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
 530         else ctx->flags |= EVP_CIPH_NO_PADDING;
 531         return 1;
 532         }
 533
 534 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 535 {
 536         int ret;
 537         if(!ctx->cipher) {
 538                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 539                 return 0;
 540         }
 541
 542         if(!ctx->cipher->ctrl) {
 543                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 544                 return 0;
 545         }
 546
 547         ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 548         if(ret == -1) {
 549                 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 550                 return 0;
 551         }
 552         return ret;
 553 }
 554
 555 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 556         {
 557         if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 558                 return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 559         if (RAND_bytes(key, ctx->key_len) <= 0)
 560                 return 0;
 561         return 1;
 562         }
 563