crypto/evp/evp_enc.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include <assert.h>
  12 #include "internal/cryptlib.h"
  13 #include <openssl/evp.h>
  14 #include <openssl/err.h>
  15 #include <openssl/rand.h>
  16 #include <openssl/rand_drbg.h>
  17 #include <openssl/engine.h>
  18 #include "internal/evp_int.h"
  19 #include "evp_locl.h"
  20
  21 int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *c)
  22 {
  23     if (c == NULL)
  24         return 1;
  25     if (c->cipher != NULL) {
  26         if (c->cipher->cleanup && !c->cipher->cleanup(c))
  27             return 0;
  28         /* Cleanse cipher context data */
  29         if (c->cipher_data && c->cipher->ctx_size)
  30             OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
  31     }
  32     OPENSSL_free(c->cipher_data);
  33 #ifndef OPENSSL_NO_ENGINE
  34     ENGINE_finish(c->engine);
  35 #endif
  36     memset(c, 0, sizeof(*c));
  37     return 1;
  38 }
  39
  40 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
  41 {
  42     return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX));
  43 }
  44
  45 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
  46 {
  47     EVP_CIPHER_CTX_reset(ctx);
  48     OPENSSL_free(ctx);
  49 }
  50
  51 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  52                    const unsigned char *key, const unsigned char *iv, int enc)
  53 {
  54     if (cipher != NULL)
  55         EVP_CIPHER_CTX_reset(ctx);
  56     return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
  57 }
  58
  59 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  60                       ENGINE *impl, const unsigned char *key,
  61                       const unsigned char *iv, int enc)
  62 {
  63     if (enc == -1)
  64         enc = ctx->encrypt;
  65     else {
  66         if (enc)
  67             enc = 1;
  68         ctx->encrypt = enc;
  69     }
  70 #ifndef OPENSSL_NO_ENGINE
  71     /*
  72      * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
  73      * this context may already have an ENGINE! Try to avoid releasing the
  74      * previous handle, re-querying for an ENGINE, and having a
  75      * reinitialisation, when it may all be unnecessary.
  76      */
  77     if (ctx->engine && ctx->cipher
  78         && (cipher == NULL || cipher->nid == ctx->cipher->nid))
  79         goto skip_to_init;
  80 #endif
  81     if (cipher) {
  82         /*
  83          * Ensure a context left lying around from last time is cleared (the
  84          * previous check attempted to avoid this if the same ENGINE and
  85          * EVP_CIPHER could be used).
  86          */
  87         if (ctx->cipher) {
  88             unsigned long flags = ctx->flags;
  89             EVP_CIPHER_CTX_reset(ctx);
  90             /* Restore encrypt and flags */
  91             ctx->encrypt = enc;
  92             ctx->flags = flags;
  93         }
  94 #ifndef OPENSSL_NO_ENGINE
  95         if (impl) {
  96             if (!ENGINE_init(impl)) {
  97                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
  98                 return 0;
  99             }
 100         } else
 101             /* Ask if an ENGINE is reserved for this job */
 102             impl = ENGINE_get_cipher_engine(cipher->nid);
 103         if (impl) {
 104             /* There's an ENGINE for this job ... (apparently) */
 105             const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 106             if (!c) {
 107                 /*
 108                  * One positive side-effect of US's export control history,
 109                  * is that we should at least be able to avoid using US
 110                  * misspellings of "initialisation"?
 111                  */
 112                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 113                 return 0;
 114             }
 115             /* We'll use the ENGINE's private cipher definition */
 116             cipher = c;
 117             /*
 118              * Store the ENGINE functional reference so we know 'cipher' came
 119              * from an ENGINE and we need to release it when done.
 120              */
 121             ctx->engine = impl;
 122         } else
 123             ctx->engine = NULL;
 124 #endif
 125
 126         ctx->cipher = cipher;
 127         if (ctx->cipher->ctx_size) {
 128             ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
 129             if (ctx->cipher_data == NULL) {
 130                 ctx->cipher = NULL;
 131                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 132                 return 0;
 133             }
 134         } else {
 135             ctx->cipher_data = NULL;
 136         }
 137         ctx->key_len = cipher->key_len;
 138         /* Preserve wrap enable flag, zero everything else */
 139         ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
 140         if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 141             if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 142                 ctx->cipher = NULL;
 143                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 144                 return 0;
 145             }
 146         }
 147     } else if (!ctx->cipher) {
 148         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
 149         return 0;
 150     }
 151 #ifndef OPENSSL_NO_ENGINE
 152  skip_to_init:
 153 #endif
 154     /* we assume block size is a power of 2 in *cryptUpdate */
 155     OPENSSL_assert(ctx->cipher->block_size == 1
 156                    || ctx->cipher->block_size == 8
 157                    || ctx->cipher->block_size == 16);
 158
 159     if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
 160         && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
 161         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
 162         return 0;
 163     }
 164
 165     if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
 166         switch (EVP_CIPHER_CTX_mode(ctx)) {
 167
 168         case EVP_CIPH_STREAM_CIPHER:
 169         case EVP_CIPH_ECB_MODE:
 170             break;
 171
 172         case EVP_CIPH_CFB_MODE:
 173         case EVP_CIPH_OFB_MODE:
 174
 175             ctx->num = 0;
 176             /* fall-through */
 177
 178         case EVP_CIPH_CBC_MODE:
 179
 180             OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 181                            (int)sizeof(ctx->iv));
 182             if (iv)
 183                 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 184             memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 185             break;
 186
 187         case EVP_CIPH_CTR_MODE:
 188             ctx->num = 0;
 189             /* Don't reuse IV for CTR mode */
 190             if (iv)
 191                 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 192             break;
 193
 194         default:
 195             return 0;
 196         }
 197     }
 198
 199     if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 200         if (!ctx->cipher->init(ctx, key, iv, enc))
 201             return 0;
 202     }
 203     ctx->buf_len = 0;
 204     ctx->final_used = 0;
 205     ctx->block_mask = ctx->cipher->block_size - 1;
 206     return 1;
 207 }
 208
 209 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 210                      const unsigned char *in, int inl)
 211 {
 212     if (ctx->encrypt)
 213         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 214     else
 215         return EVP_DecryptUpdate(ctx, out, outl, in, inl);
 216 }
 217
 218 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 219 {
 220     if (ctx->encrypt)
 221         return EVP_EncryptFinal_ex(ctx, out, outl);
 222     else
 223         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
 231         return EVP_DecryptFinal(ctx, out, outl);
 232 }
 233
 234 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 235                     const unsigned char *key, const unsigned char *iv)
 236 {
 237     return EVP_CipherInit(ctx, cipher, key, iv, 1);
 238 }
 239
 240 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 241                        ENGINE *impl, const unsigned char *key,
 242                        const unsigned char *iv)
 243 {
 244     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 245 }
 246
 247 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 248                     const unsigned char *key, const unsigned char *iv)
 249 {
 250     return EVP_CipherInit(ctx, cipher, key, iv, 0);
 251 }
 252
 253 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 254                        ENGINE *impl, const unsigned char *key,
 255                        const unsigned char *iv)
 256 {
 257     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 258 }
 259
 260 /*
 261  * According to the letter of standard difference between pointers
 262  * is specified to be valid only within same object. This makes
 263  * it formally challenging to determine if input and output buffers
 264  * are not partially overlapping with standard pointer arithmetic.
 265  */
 266 #ifdef PTRDIFF_T
 267 # undef PTRDIFF_T
 268 #endif
 269 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
 270 /*
 271  * Then we have VMS that distinguishes itself by adhering to
 272  * sizeof(size_t)==4 even in 64-bit builds, which means that
 273  * difference between two pointers might be truncated to 32 bits.
 274  * In the context one can even wonder how comparison for
 275  * equality is implemented. To be on the safe side we adhere to
 276  * PTRDIFF_T even for comparison for equality.
 277  */
 278 # define PTRDIFF_T uint64_t
 279 #else
 280 # define PTRDIFF_T size_t
 281 #endif
 282
 283 int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
 284 {
 285     PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
 286     /*
 287      * Check for partially overlapping buffers. [Binary logical
 288      * operations are used instead of boolean to minimize number
 289      * of conditional branches.]
 290      */
 291     int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
 292                                                 (diff > (0 - (PTRDIFF_T)len)));
 293
 294     return overlapped;
 295 }
 296
 297 static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
 298                                     unsigned char *out, int *outl,
 299                                     const unsigned char *in, int inl)
 300 {
 301     int i, j, bl, cmpl = inl;
 302
 303     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 304         cmpl = (cmpl + 7) / 8;
 305
 306     bl = ctx->cipher->block_size;
 307
 308     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 309         /* If block size > 1 then the cipher will have to do this check */
 310         if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
 311             EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 312             return 0;
 313         }
 314
 315         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 316         if (i < 0)
 317             return 0;
 318         else
 319             *outl = i;
 320         return 1;
 321     }
 322
 323     if (inl <= 0) {
 324         *outl = 0;
 325         return inl == 0;
 326     }
 327     if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
 328         EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 329         return 0;
 330     }
 331
 332     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 333         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 334             *outl = inl;
 335             return 1;
 336         } else {
 337             *outl = 0;
 338             return 0;
 339         }
 340     }
 341     i = ctx->buf_len;
 342     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 343     if (i != 0) {
 344         if (bl - i > inl) {
 345             memcpy(&(ctx->buf[i]), in, inl);
 346             ctx->buf_len += inl;
 347             *outl = 0;
 348             return 1;
 349         } else {
 350             j = bl - i;
 351             memcpy(&(ctx->buf[i]), in, j);
 352             inl -= j;
 353             in += j;
 354             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 355                 return 0;
 356             out += bl;
 357             *outl = bl;
 358         }
 359     } else
 360         *outl = 0;
 361     i = inl & (bl - 1);
 362     inl -= i;
 363     if (inl > 0) {
 364         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 365             return 0;
 366         *outl += inl;
 367     }
 368
 369     if (i != 0)
 370         memcpy(ctx->buf, &(in[inl]), i);
 371     ctx->buf_len = i;
 372     return 1;
 373 }
 374
 375
 376 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 377                       const unsigned char *in, int inl)
 378 {
 379     /* Prevent accidental use of decryption context when encrypting */
 380     if (!ctx->encrypt) {
 381         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
 382         return 0;
 383     }
 384
 385     return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 386 }
 387
 388 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 389 {
 390     int ret;
 391     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 392     return ret;
 393 }
 394
 395 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 396 {
 397     int n, ret;
 398     unsigned int i, b, bl;
 399
 400     /* Prevent accidental use of decryption context when encrypting */
 401     if (!ctx->encrypt) {
 402         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 403         return 0;
 404     }
 405
 406     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 407         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 408         if (ret < 0)
 409             return 0;
 410         else
 411             *outl = ret;
 412         return 1;
 413     }
 414
 415     b = ctx->cipher->block_size;
 416     OPENSSL_assert(b <= sizeof(ctx->buf));
 417     if (b == 1) {
 418         *outl = 0;
 419         return 1;
 420     }
 421     bl = ctx->buf_len;
 422     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 423         if (bl) {
 424             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 425                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 426             return 0;
 427         }
 428         *outl = 0;
 429         return 1;
 430     }
 431
 432     n = b - bl;
 433     for (i = bl; i < b; i++)
 434         ctx->buf[i] = n;
 435     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 436
 437     if (ret)
 438         *outl = b;
 439
 440     return ret;
 441 }
 442
 443 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 444                       const unsigned char *in, int inl)
 445 {
 446     int fix_len, cmpl = inl;
 447     unsigned int b;
 448
 449     /* Prevent accidental use of encryption context when decrypting */
 450     if (ctx->encrypt) {
 451         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
 452         return 0;
 453     }
 454
 455     b = ctx->cipher->block_size;
 456
 457     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 458         cmpl = (cmpl + 7) / 8;
 459
 460     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 461         if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
 462             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 463             return 0;
 464         }
 465
 466         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 467         if (fix_len < 0) {
 468             *outl = 0;
 469             return 0;
 470         } else
 471             *outl = fix_len;
 472         return 1;
 473     }
 474
 475     if (inl <= 0) {
 476         *outl = 0;
 477         return inl == 0;
 478     }
 479
 480     if (ctx->flags & EVP_CIPH_NO_PADDING)
 481         return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 482
 483     OPENSSL_assert(b <= sizeof(ctx->final));
 484
 485     if (ctx->final_used) {
 486         /* see comment about PTRDIFF_T comparison above */
 487         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
 488             || is_partially_overlapping(out, in, b)) {
 489             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 490             return 0;
 491         }
 492         memcpy(out, ctx->final, b);
 493         out += b;
 494         fix_len = 1;
 495     } else
 496         fix_len = 0;
 497
 498     if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
 499         return 0;
 500
 501     /*
 502      * if we have 'decrypted' a multiple of block size, make sure we have a
 503      * copy of this last block
 504      */
 505     if (b > 1 && !ctx->buf_len) {
 506         *outl -= b;
 507         ctx->final_used = 1;
 508         memcpy(ctx->final, &out[*outl], b);
 509     } else
 510         ctx->final_used = 0;
 511
 512     if (fix_len)
 513         *outl += b;
 514
 515     return 1;
 516 }
 517
 518 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 519 {
 520     int ret;
 521     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 522     return ret;
 523 }
 524
 525 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 526 {
 527     int i, n;
 528     unsigned int b;
 529
 530     /* Prevent accidental use of encryption context when decrypting */
 531     if (ctx->encrypt) {
 532         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 533         return 0;
 534     }
 535
 536     *outl = 0;
 537
 538     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 539         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 540         if (i < 0)
 541             return 0;
 542         else
 543             *outl = i;
 544         return 1;
 545     }
 546
 547     b = ctx->cipher->block_size;
 548     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 549         if (ctx->buf_len) {
 550             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 551                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 552             return 0;
 553         }
 554         *outl = 0;
 555         return 1;
 556     }
 557     if (b > 1) {
 558         if (ctx->buf_len || !ctx->final_used) {
 559             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 560             return 0;
 561         }
 562         OPENSSL_assert(b <= sizeof(ctx->final));
 563
 564         /*
 565          * The following assumes that the ciphertext has been authenticated.
 566          * Otherwise it provides a padding oracle.
 567          */
 568         n = ctx->final[b - 1];
 569         if (n == 0 || n > (int)b) {
 570             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 571             return 0;
 572         }
 573         for (i = 0; i < n; i++) {
 574             if (ctx->final[--b] != n) {
 575                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 576                 return 0;
 577             }
 578         }
 579         n = ctx->cipher->block_size - n;
 580         for (i = 0; i < n; i++)
 581             out[i] = ctx->final[i];
 582         *outl = n;
 583     } else
 584         *outl = 0;
 585     return 1;
 586 }
 587
 588 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 589 {
 590     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 591         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 592     if (c->key_len == keylen)
 593         return 1;
 594     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 595         c->key_len = keylen;
 596         return 1;
 597     }
 598     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 599     return 0;
 600 }
 601
 602 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 603 {
 604     if (pad)
 605         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 606     else
 607         ctx->flags |= EVP_CIPH_NO_PADDING;
 608     return 1;
 609 }
 610
 611 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 612 {
 613     int ret;
 614
 615     if (!ctx->cipher) {
 616         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 617         return 0;
 618     }
 619
 620     if (!ctx->cipher->ctrl) {
 621         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 622         return 0;
 623     }
 624
 625     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 626     if (ret == -1) {
 627         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 628                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 629         return 0;
 630     }
 631     return ret;
 632 }
 633
 634 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 635 {
 636     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 637         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 638     if (RAND_priv_bytes(key, ctx->key_len) <= 0)
 639         return 0;
 640     return 1;
 641 }
 642
 643 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 644 {
 645     if ((in == NULL) || (in->cipher == NULL)) {
 646         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 647         return 0;
 648     }
 649 #ifndef OPENSSL_NO_ENGINE
 650     /* Make sure it's safe to copy a cipher context using an ENGINE */
 651     if (in->engine && !ENGINE_init(in->engine)) {
 652         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
 653         return 0;
 654     }
 655 #endif
 656
 657     EVP_CIPHER_CTX_reset(out);
 658     memcpy(out, in, sizeof(*out));
 659
 660     if (in->cipher_data && in->cipher->ctx_size) {
 661         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
 662         if (out->cipher_data == NULL) {
 663             out->cipher = NULL;
 664             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
 665             return 0;
 666         }
 667         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
 668     }
 669
 670     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
 671         if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
 672             out->cipher = NULL;
 673             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
 674             return 0;
 675         }
 676     return 1;
 677 }