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 "internal/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 "internal/evp_int.h"
  68 #include "evp_locl.h"
  69
  70 int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *c)
  71 {
  72     if (c == NULL)
  73         return 1;
  74     if (c->cipher != NULL) {
  75         if (c->cipher->cleanup && !c->cipher->cleanup(c))
  76             return 0;
  77         /* Cleanse cipher context data */
  78         if (c->cipher_data && c->cipher->ctx_size)
  79             OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
  80     }
  81     OPENSSL_free(c->cipher_data);
  82 #ifndef OPENSSL_NO_ENGINE
  83     if (c->engine)
  84         /*
  85          * The EVP_CIPHER we used belongs to an ENGINE, release the
  86          * functional reference we held for this reason.
  87          */
  88         ENGINE_finish(c->engine);
  89 #endif
  90     memset(c, 0, sizeof(*c));
  91     return 1;
  92 }
  93
  94 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
  95 {
  96     return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX));
  97 }
  98
  99 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
 100 {
 101     EVP_CIPHER_CTX_reset(ctx);
 102     OPENSSL_free(ctx);
 103 }
 104
 105 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 106                    const unsigned char *key, const unsigned char *iv, int enc)
 107 {
 108     EVP_CIPHER_CTX_reset(ctx);
 109     return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
 110 }
 111
 112 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 113                       ENGINE *impl, const unsigned char *key,
 114                       const unsigned char *iv, int enc)
 115 {
 116     if (enc == -1)
 117         enc = ctx->encrypt;
 118     else {
 119         if (enc)
 120             enc = 1;
 121         ctx->encrypt = enc;
 122     }
 123 #ifndef OPENSSL_NO_ENGINE
 124     /*
 125      * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
 126      * this context may already have an ENGINE! Try to avoid releasing the
 127      * previous handle, re-querying for an ENGINE, and having a
 128      * reinitialisation, when it may all be unecessary.
 129      */
 130     if (ctx->engine && ctx->cipher
 131         && (!cipher || (cipher && (cipher->nid == ctx->cipher->nid))))
 132         goto skip_to_init;
 133 #endif
 134     if (cipher) {
 135         /*
 136          * Ensure a context left lying around from last time is cleared (the
 137          * previous check attempted to avoid this if the same ENGINE and
 138          * EVP_CIPHER could be used).
 139          */
 140         if (ctx->cipher) {
 141             unsigned long flags = ctx->flags;
 142             EVP_CIPHER_CTX_reset(ctx);
 143             /* Restore encrypt and flags */
 144             ctx->encrypt = enc;
 145             ctx->flags = flags;
 146         }
 147 #ifndef OPENSSL_NO_ENGINE
 148         if (impl) {
 149             if (!ENGINE_init(impl)) {
 150                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 151                 return 0;
 152             }
 153         } else
 154             /* Ask if an ENGINE is reserved for this job */
 155             impl = ENGINE_get_cipher_engine(cipher->nid);
 156         if (impl) {
 157             /* There's an ENGINE for this job ... (apparently) */
 158             const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 159             if (!c) {
 160                 /*
 161                  * One positive side-effect of US's export control history,
 162                  * is that we should at least be able to avoid using US
 163                  * mispellings of "initialisation"?
 164                  */
 165                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 166                 return 0;
 167             }
 168             /* We'll use the ENGINE's private cipher definition */
 169             cipher = c;
 170             /*
 171              * Store the ENGINE functional reference so we know 'cipher' came
 172              * from an ENGINE and we need to release it when done.
 173              */
 174             ctx->engine = impl;
 175         } else
 176             ctx->engine = NULL;
 177 #endif
 178
 179         ctx->cipher = cipher;
 180         if (ctx->cipher->ctx_size) {
 181             ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
 182             if (ctx->cipher_data == NULL) {
 183                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 184                 return 0;
 185             }
 186         } else {
 187             ctx->cipher_data = NULL;
 188         }
 189         ctx->key_len = cipher->key_len;
 190         /* Preserve wrap enable flag, zero everything else */
 191         ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
 192         if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 193             if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 194                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 195                 return 0;
 196             }
 197         }
 198     } else if (!ctx->cipher) {
 199         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
 200         return 0;
 201     }
 202 #ifndef OPENSSL_NO_ENGINE
 203  skip_to_init:
 204 #endif
 205     /* we assume block size is a power of 2 in *cryptUpdate */
 206     OPENSSL_assert(ctx->cipher->block_size == 1
 207                    || ctx->cipher->block_size == 8
 208                    || ctx->cipher->block_size == 16);
 209
 210     if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
 211         && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
 212         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
 213         return 0;
 214     }
 215
 216     if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
 217         switch (EVP_CIPHER_CTX_mode(ctx)) {
 218
 219         case EVP_CIPH_STREAM_CIPHER:
 220         case EVP_CIPH_ECB_MODE:
 221             break;
 222
 223         case EVP_CIPH_CFB_MODE:
 224         case EVP_CIPH_OFB_MODE:
 225
 226             ctx->num = 0;
 227             /* fall-through */
 228
 229         case EVP_CIPH_CBC_MODE:
 230
 231             OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 232                            (int)sizeof(ctx->iv));
 233             if (iv)
 234                 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 235             memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 236             break;
 237
 238         case EVP_CIPH_CTR_MODE:
 239             ctx->num = 0;
 240             /* Don't reuse IV for CTR mode */
 241             if (iv)
 242                 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 243             break;
 244
 245         default:
 246             return 0;
 247         }
 248     }
 249
 250     if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 251         if (!ctx->cipher->init(ctx, key, iv, enc))
 252             return 0;
 253     }
 254     ctx->buf_len = 0;
 255     ctx->final_used = 0;
 256     ctx->block_mask = ctx->cipher->block_size - 1;
 257     return 1;
 258 }
 259
 260 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 261                      const unsigned char *in, int inl)
 262 {
 263     if (ctx->encrypt)
 264         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 265     else
 266         return EVP_DecryptUpdate(ctx, out, outl, in, inl);
 267 }
 268
 269 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 270 {
 271     if (ctx->encrypt)
 272         return EVP_EncryptFinal_ex(ctx, out, outl);
 273     else
 274         return EVP_DecryptFinal_ex(ctx, out, outl);
 275 }
 276
 277 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 278 {
 279     if (ctx->encrypt)
 280         return EVP_EncryptFinal(ctx, out, outl);
 281     else
 282         return EVP_DecryptFinal(ctx, out, outl);
 283 }
 284
 285 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 286                     const unsigned char *key, const unsigned char *iv)
 287 {
 288     return EVP_CipherInit(ctx, cipher, key, iv, 1);
 289 }
 290
 291 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 292                        ENGINE *impl, const unsigned char *key,
 293                        const unsigned char *iv)
 294 {
 295     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 296 }
 297
 298 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 299                     const unsigned char *key, const unsigned char *iv)
 300 {
 301     return EVP_CipherInit(ctx, cipher, key, iv, 0);
 302 }
 303
 304 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 305                        ENGINE *impl, const unsigned char *key,
 306                        const unsigned char *iv)
 307 {
 308     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 309 }
 310
 311 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 312                       const unsigned char *in, int inl)
 313 {
 314     int i, j, bl;
 315
 316     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 317         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 318         if (i < 0)
 319             return 0;
 320         else
 321             *outl = i;
 322         return 1;
 323     }
 324
 325     if (inl <= 0) {
 326         *outl = 0;
 327         return inl == 0;
 328     }
 329
 330     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 331         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 332             *outl = inl;
 333             return 1;
 334         } else {
 335             *outl = 0;
 336             return 0;
 337         }
 338     }
 339     i = ctx->buf_len;
 340     bl = ctx->cipher->block_size;
 341     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 342     if (i != 0) {
 343         if (i + inl < bl) {
 344             memcpy(&(ctx->buf[i]), in, inl);
 345             ctx->buf_len += inl;
 346             *outl = 0;
 347             return 1;
 348         } else {
 349             j = bl - i;
 350             memcpy(&(ctx->buf[i]), in, j);
 351             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 352                 return 0;
 353             inl -= j;
 354             in += j;
 355             out += bl;
 356             *outl = bl;
 357         }
 358     } else
 359         *outl = 0;
 360     i = inl & (bl - 1);
 361     inl -= i;
 362     if (inl > 0) {
 363         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 364             return 0;
 365         *outl += inl;
 366     }
 367
 368     if (i != 0)
 369         memcpy(ctx->buf, &(in[inl]), i);
 370     ctx->buf_len = i;
 371     return 1;
 372 }
 373
 374 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 375 {
 376     int ret;
 377     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 378     return ret;
 379 }
 380
 381 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 382 {
 383     int n, ret;
 384     unsigned int i, b, bl;
 385
 386     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 387         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 388         if (ret < 0)
 389             return 0;
 390         else
 391             *outl = ret;
 392         return 1;
 393     }
 394
 395     b = ctx->cipher->block_size;
 396     OPENSSL_assert(b <= sizeof ctx->buf);
 397     if (b == 1) {
 398         *outl = 0;
 399         return 1;
 400     }
 401     bl = ctx->buf_len;
 402     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 403         if (bl) {
 404             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 405                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 406             return 0;
 407         }
 408         *outl = 0;
 409         return 1;
 410     }
 411
 412     n = b - bl;
 413     for (i = bl; i < b; i++)
 414         ctx->buf[i] = n;
 415     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 416
 417     if (ret)
 418         *outl = b;
 419
 420     return ret;
 421 }
 422
 423 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 424                       const unsigned char *in, int inl)
 425 {
 426     int fix_len;
 427     unsigned int b;
 428
 429     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 430         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 431         if (fix_len < 0) {
 432             *outl = 0;
 433             return 0;
 434         } else
 435             *outl = fix_len;
 436         return 1;
 437     }
 438
 439     if (inl <= 0) {
 440         *outl = 0;
 441         return inl == 0;
 442     }
 443
 444     if (ctx->flags & EVP_CIPH_NO_PADDING)
 445         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 446
 447     b = ctx->cipher->block_size;
 448     OPENSSL_assert(b <= sizeof ctx->final);
 449
 450     if (ctx->final_used) {
 451         memcpy(out, ctx->final, b);
 452         out += b;
 453         fix_len = 1;
 454     } else
 455         fix_len = 0;
 456
 457     if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))
 458         return 0;
 459
 460     /*
 461      * if we have 'decrypted' a multiple of block size, make sure we have a
 462      * copy of this last block
 463      */
 464     if (b > 1 && !ctx->buf_len) {
 465         *outl -= b;
 466         ctx->final_used = 1;
 467         memcpy(ctx->final, &out[*outl], b);
 468     } else
 469         ctx->final_used = 0;
 470
 471     if (fix_len)
 472         *outl += b;
 473
 474     return 1;
 475 }
 476
 477 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 478 {
 479     int ret;
 480     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 481     return ret;
 482 }
 483
 484 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 485 {
 486     int i, n;
 487     unsigned int b;
 488     *outl = 0;
 489
 490     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 491         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 492         if (i < 0)
 493             return 0;
 494         else
 495             *outl = i;
 496         return 1;
 497     }
 498
 499     b = ctx->cipher->block_size;
 500     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 501         if (ctx->buf_len) {
 502             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 503                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 504             return 0;
 505         }
 506         *outl = 0;
 507         return 1;
 508     }
 509     if (b > 1) {
 510         if (ctx->buf_len || !ctx->final_used) {
 511             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 512             return (0);
 513         }
 514         OPENSSL_assert(b <= sizeof ctx->final);
 515
 516         /*
 517          * The following assumes that the ciphertext has been authenticated.
 518          * Otherwise it provides a padding oracle.
 519          */
 520         n = ctx->final[b - 1];
 521         if (n == 0 || n > (int)b) {
 522             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 523             return (0);
 524         }
 525         for (i = 0; i < n; i++) {
 526             if (ctx->final[--b] != n) {
 527                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 528                 return (0);
 529             }
 530         }
 531         n = ctx->cipher->block_size - n;
 532         for (i = 0; i < n; i++)
 533             out[i] = ctx->final[i];
 534         *outl = n;
 535     } else
 536         *outl = 0;
 537     return (1);
 538 }
 539
 540 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 541 {
 542     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 543         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 544     if (c->key_len == keylen)
 545         return 1;
 546     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 547         c->key_len = keylen;
 548         return 1;
 549     }
 550     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 551     return 0;
 552 }
 553
 554 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 555 {
 556     if (pad)
 557         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 558     else
 559         ctx->flags |= EVP_CIPH_NO_PADDING;
 560     return 1;
 561 }
 562
 563 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 564 {
 565     int ret;
 566     if (!ctx->cipher) {
 567         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 568         return 0;
 569     }
 570
 571     if (!ctx->cipher->ctrl) {
 572         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 573         return 0;
 574     }
 575
 576     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 577     if (ret == -1) {
 578         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 579                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 580         return 0;
 581     }
 582     return ret;
 583 }
 584
 585 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 586 {
 587     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 588         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 589     if (RAND_bytes(key, ctx->key_len) <= 0)
 590         return 0;
 591     return 1;
 592 }
 593
 594 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 595 {
 596     if ((in == NULL) || (in->cipher == NULL)) {
 597         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 598         return 0;
 599     }
 600 #ifndef OPENSSL_NO_ENGINE
 601     /* Make sure it's safe to copy a cipher context using an ENGINE */
 602     if (in->engine && !ENGINE_init(in->engine)) {
 603         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
 604         return 0;
 605     }
 606 #endif
 607
 608     EVP_CIPHER_CTX_reset(out);
 609     memcpy(out, in, sizeof(*out));
 610
 611     if (in->cipher_data && in->cipher->ctx_size) {
 612         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
 613         if (out->cipher_data == NULL) {
 614             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
 615             return 0;
 616         }
 617         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
 618     }
 619
 620     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
 621         return in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out);
 622     return 1;
 623 }