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