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 <openssl/params.h>
  19 #include <openssl/core_names.h>
  20 #include "internal/evp_int.h"
  21 #include "internal/provider.h"
  22 #include "evp_locl.h"
  23
  24 int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx)
  25 {
  26     if (ctx == NULL)
  27         return 1;
  28
  29     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
  30         goto legacy;
  31
  32     if (ctx->provctx != NULL) {
  33         if (ctx->cipher->freectx != NULL)
  34             ctx->cipher->freectx(ctx->provctx);
  35         ctx->provctx = NULL;
  36     }
  37     if (ctx->fetched_cipher != NULL)
  38         EVP_CIPHER_meth_free(ctx->fetched_cipher);
  39     memset(ctx, 0, sizeof(*ctx));
  40
  41     return 1;
  42
  43     /* TODO(3.0): Remove legacy code below */
  44  legacy:
  45
  46     if (ctx->cipher != NULL) {
  47         if (ctx->cipher->cleanup && !ctx->cipher->cleanup(ctx))
  48             return 0;
  49         /* Cleanse cipher context data */
  50         if (ctx->cipher_data && ctx->cipher->ctx_size)
  51             OPENSSL_cleanse(ctx->cipher_data, ctx->cipher->ctx_size);
  52     }
  53     OPENSSL_free(ctx->cipher_data);
  54 #ifndef OPENSSL_NO_ENGINE
  55     ENGINE_finish(ctx->engine);
  56 #endif
  57     memset(ctx, 0, sizeof(*ctx));
  58     return 1;
  59 }
  60
  61 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
  62 {
  63     return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX));
  64 }
  65
  66 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
  67 {
  68     EVP_CIPHER_CTX_reset(ctx);
  69     OPENSSL_free(ctx);
  70 }
  71
  72 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  73                    const unsigned char *key, const unsigned char *iv, int enc)
  74 {
  75     if (cipher != NULL)
  76         EVP_CIPHER_CTX_reset(ctx);
  77     return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
  78 }
  79
  80 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
  81                       ENGINE *impl, const unsigned char *key,
  82                       const unsigned char *iv, int enc)
  83 {
  84     EVP_CIPHER *provciph = NULL;
  85     ENGINE *tmpimpl = NULL;
  86     const EVP_CIPHER *tmpcipher;
  87
  88     /*
  89      * enc == 1 means we are encrypting.
  90      * enc == 0 means we are decrypting.
  91      * enc == -1 means, use the previously initialised value for encrypt/decrypt
  92      */
  93     if (enc == -1) {
  94         enc = ctx->encrypt;
  95     } else {
  96         if (enc)
  97             enc = 1;
  98         ctx->encrypt = enc;
  99     }
 100
 101     if (cipher == NULL && ctx->cipher == NULL) {
 102         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
 103         return 0;
 104     }
 105
 106     /* TODO(3.0): Legacy work around code below. Remove this */
 107
 108 #ifndef OPENSSL_NO_ENGINE
 109     /*
 110      * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
 111      * this context may already have an ENGINE! Try to avoid releasing the
 112      * previous handle, re-querying for an ENGINE, and having a
 113      * reinitialisation, when it may all be unnecessary.
 114      */
 115     if (ctx->engine && ctx->cipher
 116         && (cipher == NULL || cipher->nid == ctx->cipher->nid))
 117         goto skip_to_init;
 118
 119     if (cipher != NULL && impl == NULL) {
 120          /* Ask if an ENGINE is reserved for this job */
 121         tmpimpl = ENGINE_get_cipher_engine(cipher->nid);
 122     }
 123 #endif
 124
 125     /*
 126      * If there are engines involved then we should use legacy handling for now.
 127      */
 128     if (ctx->engine != NULL
 129             || impl != NULL
 130             || tmpimpl != NULL) {
 131         if (ctx->cipher == ctx->fetched_cipher)
 132             ctx->cipher = NULL;
 133         EVP_CIPHER_meth_free(ctx->fetched_cipher);
 134         ctx->fetched_cipher = NULL;
 135         goto legacy;
 136     }
 137
 138     tmpcipher = (cipher == NULL) ? ctx->cipher : cipher;
 139
 140     if (tmpcipher->prov == NULL) {
 141         switch(tmpcipher->nid) {
 142         case NID_aes_256_ecb:
 143         case NID_aes_192_ecb:
 144         case NID_aes_128_ecb:
 145         case NID_aes_256_cbc:
 146         case NID_aes_192_cbc:
 147         case NID_aes_128_cbc:
 148         case NID_aes_256_ofb128:
 149         case NID_aes_192_ofb128:
 150         case NID_aes_128_ofb128:
 151         case NID_aes_256_cfb128:
 152         case NID_aes_192_cfb128:
 153         case NID_aes_128_cfb128:
 154         case NID_aes_256_cfb1:
 155         case NID_aes_192_cfb1:
 156         case NID_aes_128_cfb1:
 157         case NID_aes_256_cfb8:
 158         case NID_aes_192_cfb8:
 159         case NID_aes_128_cfb8:
 160         case NID_aes_256_ctr:
 161         case NID_aes_192_ctr:
 162         case NID_aes_128_ctr:
 163             break;
 164         default:
 165             goto legacy;
 166         }
 167     }
 168
 169     /*
 170      * Ensure a context left lying around from last time is cleared
 171      * (legacy code)
 172      */
 173     if (cipher != NULL && ctx->cipher != NULL) {
 174         OPENSSL_clear_free(ctx->cipher_data, ctx->cipher->ctx_size);
 175         ctx->cipher_data = NULL;
 176     }
 177
 178
 179     /* TODO(3.0): Start of non-legacy code below */
 180
 181     /* Ensure a context left lying around from last time is cleared */
 182     if (cipher != NULL && ctx->cipher != NULL) {
 183         unsigned long flags = ctx->flags;
 184
 185         EVP_CIPHER_CTX_reset(ctx);
 186         /* Restore encrypt and flags */
 187         ctx->encrypt = enc;
 188         ctx->flags = flags;
 189     }
 190
 191     if (cipher != NULL)
 192         ctx->cipher = cipher;
 193     else
 194         cipher = ctx->cipher;
 195
 196     if (cipher->prov == NULL) {
 197         provciph = EVP_CIPHER_fetch(NULL, OBJ_nid2sn(cipher->nid), "");
 198         if (provciph == NULL) {
 199             EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 200             return 0;
 201         }
 202         cipher = provciph;
 203         EVP_CIPHER_meth_free(ctx->fetched_cipher);
 204         ctx->fetched_cipher = provciph;
 205     }
 206
 207     ctx->cipher = cipher;
 208     if (ctx->provctx == NULL) {
 209         ctx->provctx = ctx->cipher->newctx();
 210         if (ctx->provctx == NULL) {
 211             EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 212             return 0;
 213         }
 214     }
 215
 216     if ((ctx->flags & EVP_CIPH_NO_PADDING) != 0) {
 217         /*
 218          * If this ctx was already set up for no padding then we need to tell
 219          * the new cipher about it.
 220          */
 221         if (!EVP_CIPHER_CTX_set_padding(ctx, 0))
 222             return 0;
 223     }
 224
 225     switch (EVP_CIPHER_mode(ctx->cipher)) {
 226     case EVP_CIPH_CFB_MODE:
 227     case EVP_CIPH_OFB_MODE:
 228     case EVP_CIPH_CBC_MODE:
 229         /* For these modes we remember the original IV for later use */
 230         if (!ossl_assert(EVP_CIPHER_CTX_iv_length(ctx) <= (int)sizeof(ctx->oiv))) {
 231             EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 232             return 0;
 233         }
 234         if (iv != NULL)
 235             memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 236     }
 237
 238     if (enc) {
 239         if (ctx->cipher->einit == NULL) {
 240             EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 241             return 0;
 242         }
 243
 244         return ctx->cipher->einit(ctx->provctx, key, iv);
 245     }
 246
 247     if (ctx->cipher->dinit == NULL) {
 248         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 249         return 0;
 250     }
 251
 252     return ctx->cipher->dinit(ctx->provctx, key, iv);
 253
 254     /* TODO(3.0): Remove legacy code below */
 255  legacy:
 256
 257     if (cipher != NULL) {
 258         /*
 259          * Ensure a context left lying around from last time is cleared (we
 260          * previously attempted to avoid this if the same ENGINE and
 261          * EVP_CIPHER could be used).
 262          */
 263         if (ctx->cipher) {
 264             unsigned long flags = ctx->flags;
 265             EVP_CIPHER_CTX_reset(ctx);
 266             /* Restore encrypt and flags */
 267             ctx->encrypt = enc;
 268             ctx->flags = flags;
 269         }
 270 #ifndef OPENSSL_NO_ENGINE
 271         if (impl != NULL) {
 272             if (!ENGINE_init(impl)) {
 273                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 274                 return 0;
 275             }
 276         } else {
 277             impl = tmpimpl;
 278         }
 279         if (impl != NULL) {
 280             /* There's an ENGINE for this job ... (apparently) */
 281             const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 282
 283             if (c == NULL) {
 284                 /*
 285                  * One positive side-effect of US's export control history,
 286                  * is that we should at least be able to avoid using US
 287                  * misspellings of "initialisation"?
 288                  */
 289                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 290                 return 0;
 291             }
 292             /* We'll use the ENGINE's private cipher definition */
 293             cipher = c;
 294             /*
 295              * Store the ENGINE functional reference so we know 'cipher' came
 296              * from an ENGINE and we need to release it when done.
 297              */
 298             ctx->engine = impl;
 299         } else {
 300             ctx->engine = NULL;
 301         }
 302 #endif
 303
 304         ctx->cipher = cipher;
 305         if (ctx->cipher->ctx_size) {
 306             ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
 307             if (ctx->cipher_data == NULL) {
 308                 ctx->cipher = NULL;
 309                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 310                 return 0;
 311             }
 312         } else {
 313             ctx->cipher_data = NULL;
 314         }
 315         ctx->key_len = cipher->key_len;
 316         /* Preserve wrap enable flag, zero everything else */
 317         ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
 318         if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 319             if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 320                 ctx->cipher = NULL;
 321                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 322                 return 0;
 323             }
 324         }
 325     }
 326 #ifndef OPENSSL_NO_ENGINE
 327  skip_to_init:
 328 #endif
 329     /* we assume block size is a power of 2 in *cryptUpdate */
 330     OPENSSL_assert(ctx->cipher->block_size == 1
 331                    || ctx->cipher->block_size == 8
 332                    || ctx->cipher->block_size == 16);
 333
 334     if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
 335         && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
 336         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
 337         return 0;
 338     }
 339
 340     if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
 341         switch (EVP_CIPHER_CTX_mode(ctx)) {
 342
 343         case EVP_CIPH_STREAM_CIPHER:
 344         case EVP_CIPH_ECB_MODE:
 345             break;
 346
 347         case EVP_CIPH_CFB_MODE:
 348         case EVP_CIPH_OFB_MODE:
 349
 350             ctx->num = 0;
 351             /* fall-through */
 352
 353         case EVP_CIPH_CBC_MODE:
 354
 355             OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 356                            (int)sizeof(ctx->iv));
 357             if (iv)
 358                 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 359             memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 360             break;
 361
 362         case EVP_CIPH_CTR_MODE:
 363             ctx->num = 0;
 364             /* Don't reuse IV for CTR mode */
 365             if (iv)
 366                 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 367             break;
 368
 369         default:
 370             return 0;
 371         }
 372     }
 373
 374     if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 375         if (!ctx->cipher->init(ctx, key, iv, enc))
 376             return 0;
 377     }
 378     ctx->buf_len = 0;
 379     ctx->final_used = 0;
 380     ctx->block_mask = ctx->cipher->block_size - 1;
 381     return 1;
 382 }
 383
 384 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 385                      const unsigned char *in, int inl)
 386 {
 387     if (ctx->encrypt)
 388         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 389     else
 390         return EVP_DecryptUpdate(ctx, out, outl, in, inl);
 391 }
 392
 393 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 394 {
 395     if (ctx->encrypt)
 396         return EVP_EncryptFinal_ex(ctx, out, outl);
 397     else
 398         return EVP_DecryptFinal_ex(ctx, out, outl);
 399 }
 400
 401 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 402 {
 403     if (ctx->encrypt)
 404         return EVP_EncryptFinal(ctx, out, outl);
 405     else
 406         return EVP_DecryptFinal(ctx, out, outl);
 407 }
 408
 409 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 410                     const unsigned char *key, const unsigned char *iv)
 411 {
 412     return EVP_CipherInit(ctx, cipher, key, iv, 1);
 413 }
 414
 415 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 416                        ENGINE *impl, const unsigned char *key,
 417                        const unsigned char *iv)
 418 {
 419     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 420 }
 421
 422 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 423                     const unsigned char *key, const unsigned char *iv)
 424 {
 425     return EVP_CipherInit(ctx, cipher, key, iv, 0);
 426 }
 427
 428 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 429                        ENGINE *impl, const unsigned char *key,
 430                        const unsigned char *iv)
 431 {
 432     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 433 }
 434
 435 /*
 436  * According to the letter of standard difference between pointers
 437  * is specified to be valid only within same object. This makes
 438  * it formally challenging to determine if input and output buffers
 439  * are not partially overlapping with standard pointer arithmetic.
 440  */
 441 #ifdef PTRDIFF_T
 442 # undef PTRDIFF_T
 443 #endif
 444 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
 445 /*
 446  * Then we have VMS that distinguishes itself by adhering to
 447  * sizeof(size_t)==4 even in 64-bit builds, which means that
 448  * difference between two pointers might be truncated to 32 bits.
 449  * In the context one can even wonder how comparison for
 450  * equality is implemented. To be on the safe side we adhere to
 451  * PTRDIFF_T even for comparison for equality.
 452  */
 453 # define PTRDIFF_T uint64_t
 454 #else
 455 # define PTRDIFF_T size_t
 456 #endif
 457
 458 int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
 459 {
 460     PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
 461     /*
 462      * Check for partially overlapping buffers. [Binary logical
 463      * operations are used instead of boolean to minimize number
 464      * of conditional branches.]
 465      */
 466     int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
 467                                                 (diff > (0 - (PTRDIFF_T)len)));
 468
 469     return overlapped;
 470 }
 471
 472 static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
 473                                     unsigned char *out, int *outl,
 474                                     const unsigned char *in, int inl)
 475 {
 476     int i, j, bl, cmpl = inl;
 477
 478     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 479         cmpl = (cmpl + 7) / 8;
 480
 481     bl = ctx->cipher->block_size;
 482
 483     if (inl <= 0) {
 484         *outl = 0;
 485         return inl == 0;
 486     }
 487
 488     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 489         /* If block size > 1 then the cipher will have to do this check */
 490         if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
 491             EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 492             return 0;
 493         }
 494
 495         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 496         if (i < 0)
 497             return 0;
 498         else
 499             *outl = i;
 500         return 1;
 501     }
 502
 503     if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
 504         EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 505         return 0;
 506     }
 507
 508     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 509         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 510             *outl = inl;
 511             return 1;
 512         } else {
 513             *outl = 0;
 514             return 0;
 515         }
 516     }
 517     i = ctx->buf_len;
 518     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 519     if (i != 0) {
 520         if (bl - i > inl) {
 521             memcpy(&(ctx->buf[i]), in, inl);
 522             ctx->buf_len += inl;
 523             *outl = 0;
 524             return 1;
 525         } else {
 526             j = bl - i;
 527             memcpy(&(ctx->buf[i]), in, j);
 528             inl -= j;
 529             in += j;
 530             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 531                 return 0;
 532             out += bl;
 533             *outl = bl;
 534         }
 535     } else
 536         *outl = 0;
 537     i = inl & (bl - 1);
 538     inl -= i;
 539     if (inl > 0) {
 540         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 541             return 0;
 542         *outl += inl;
 543     }
 544
 545     if (i != 0)
 546         memcpy(ctx->buf, &(in[inl]), i);
 547     ctx->buf_len = i;
 548     return 1;
 549 }
 550
 551
 552 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 553                       const unsigned char *in, int inl)
 554 {
 555     int ret;
 556     size_t soutl;
 557
 558     /* Prevent accidental use of decryption context when encrypting */
 559     if (!ctx->encrypt) {
 560         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
 561         return 0;
 562     }
 563
 564     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 565         goto legacy;
 566
 567     if (ctx->cipher->cupdate == NULL) {
 568         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 569         return 0;
 570     }
 571     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl, in, (size_t)inl);
 572
 573     if (soutl > INT_MAX) {
 574         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 575         return 0;
 576     }
 577     *outl = soutl;
 578     return ret;
 579
 580     /* TODO(3.0): Remove legacy code below */
 581  legacy:
 582
 583     return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 584 }
 585
 586 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 587 {
 588     int ret;
 589     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 590     return ret;
 591 }
 592
 593 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 594 {
 595     int n, ret;
 596     unsigned int i, b, bl;
 597     size_t soutl;
 598
 599     /* Prevent accidental use of decryption context when encrypting */
 600     if (!ctx->encrypt) {
 601         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 602         return 0;
 603     }
 604
 605     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 606         goto legacy;
 607
 608     if (ctx->cipher->cfinal == NULL) {
 609         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 610         return 0;
 611     }
 612
 613     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl);
 614
 615     if (soutl > INT_MAX) {
 616         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 617         return 0;
 618     }
 619     *outl = soutl;
 620
 621     return ret;
 622
 623     /* TODO(3.0): Remove legacy code below */
 624  legacy:
 625
 626     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 627         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 628         if (ret < 0)
 629             return 0;
 630         else
 631             *outl = ret;
 632         return 1;
 633     }
 634
 635     b = ctx->cipher->block_size;
 636     OPENSSL_assert(b <= sizeof(ctx->buf));
 637     if (b == 1) {
 638         *outl = 0;
 639         return 1;
 640     }
 641     bl = ctx->buf_len;
 642     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 643         if (bl) {
 644             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 645                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 646             return 0;
 647         }
 648         *outl = 0;
 649         return 1;
 650     }
 651
 652     n = b - bl;
 653     for (i = bl; i < b; i++)
 654         ctx->buf[i] = n;
 655     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 656
 657     if (ret)
 658         *outl = b;
 659
 660     return ret;
 661 }
 662
 663 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 664                       const unsigned char *in, int inl)
 665 {
 666     int fix_len, cmpl = inl, ret;
 667     unsigned int b;
 668     size_t soutl;
 669
 670     /* Prevent accidental use of encryption context when decrypting */
 671     if (ctx->encrypt) {
 672         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
 673         return 0;
 674     }
 675
 676     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 677         goto legacy;
 678
 679     if (ctx->cipher->cupdate == NULL) {
 680         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 681         return 0;
 682     }
 683     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl, in, (size_t)inl);
 684
 685     if (ret) {
 686         if (soutl > INT_MAX) {
 687             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 688             return 0;
 689         }
 690         *outl = soutl;
 691     }
 692
 693     return ret;
 694
 695     /* TODO(3.0): Remove legacy code below */
 696  legacy:
 697
 698     b = ctx->cipher->block_size;
 699
 700     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 701         cmpl = (cmpl + 7) / 8;
 702
 703     if (inl <= 0) {
 704         *outl = 0;
 705         return inl == 0;
 706     }
 707
 708     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 709         if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
 710             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 711             return 0;
 712         }
 713
 714         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 715         if (fix_len < 0) {
 716             *outl = 0;
 717             return 0;
 718         } else
 719             *outl = fix_len;
 720         return 1;
 721     }
 722
 723     if (ctx->flags & EVP_CIPH_NO_PADDING)
 724         return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 725
 726     OPENSSL_assert(b <= sizeof(ctx->final));
 727
 728     if (ctx->final_used) {
 729         /* see comment about PTRDIFF_T comparison above */
 730         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
 731             || is_partially_overlapping(out, in, b)) {
 732             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 733             return 0;
 734         }
 735         memcpy(out, ctx->final, b);
 736         out += b;
 737         fix_len = 1;
 738     } else
 739         fix_len = 0;
 740
 741     if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
 742         return 0;
 743
 744     /*
 745      * if we have 'decrypted' a multiple of block size, make sure we have a
 746      * copy of this last block
 747      */
 748     if (b > 1 && !ctx->buf_len) {
 749         *outl -= b;
 750         ctx->final_used = 1;
 751         memcpy(ctx->final, &out[*outl], b);
 752     } else
 753         ctx->final_used = 0;
 754
 755     if (fix_len)
 756         *outl += b;
 757
 758     return 1;
 759 }
 760
 761 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 762 {
 763     int ret;
 764     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 765     return ret;
 766 }
 767
 768 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 769 {
 770     int i, n;
 771     unsigned int b;
 772     size_t soutl;
 773     int ret;
 774
 775     /* Prevent accidental use of encryption context when decrypting */
 776     if (ctx->encrypt) {
 777         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 778         return 0;
 779     }
 780
 781     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 782         goto legacy;
 783
 784     if (ctx->cipher->cfinal == NULL) {
 785         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 786         return 0;
 787     }
 788
 789     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl);
 790
 791     if (ret) {
 792         if (soutl > INT_MAX) {
 793             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 794             return 0;
 795         }
 796         *outl = soutl;
 797     }
 798
 799     return ret;
 800
 801     /* TODO(3.0): Remove legacy code below */
 802  legacy:
 803
 804     *outl = 0;
 805
 806     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 807         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 808         if (i < 0)
 809             return 0;
 810         else
 811             *outl = i;
 812         return 1;
 813     }
 814
 815     b = ctx->cipher->block_size;
 816     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 817         if (ctx->buf_len) {
 818             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 819                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 820             return 0;
 821         }
 822         *outl = 0;
 823         return 1;
 824     }
 825     if (b > 1) {
 826         if (ctx->buf_len || !ctx->final_used) {
 827             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 828             return 0;
 829         }
 830         OPENSSL_assert(b <= sizeof(ctx->final));
 831
 832         /*
 833          * The following assumes that the ciphertext has been authenticated.
 834          * Otherwise it provides a padding oracle.
 835          */
 836         n = ctx->final[b - 1];
 837         if (n == 0 || n > (int)b) {
 838             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 839             return 0;
 840         }
 841         for (i = 0; i < n; i++) {
 842             if (ctx->final[--b] != n) {
 843                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 844                 return 0;
 845             }
 846         }
 847         n = ctx->cipher->block_size - n;
 848         for (i = 0; i < n; i++)
 849             out[i] = ctx->final[i];
 850         *outl = n;
 851     } else
 852         *outl = 0;
 853     return 1;
 854 }
 855
 856 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 857 {
 858     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 859         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 860     if (EVP_CIPHER_CTX_key_length(c) == keylen)
 861         return 1;
 862     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 863         c->key_len = keylen;
 864         return 1;
 865     }
 866     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 867     return 0;
 868 }
 869
 870 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 871 {
 872     if (pad)
 873         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 874     else
 875         ctx->flags |= EVP_CIPH_NO_PADDING;
 876
 877     if (ctx->cipher != NULL && ctx->cipher->prov != NULL) {
 878         OSSL_PARAM params[] = {
 879             OSSL_PARAM_int(OSSL_CIPHER_PARAM_PADDING, NULL),
 880             OSSL_PARAM_END
 881         };
 882
 883         params[0].data = &pad;
 884
 885         if (ctx->cipher->ctx_set_params == NULL) {
 886             EVPerr(EVP_F_EVP_CIPHER_CTX_SET_PADDING, EVP_R_CTRL_NOT_IMPLEMENTED);
 887             return 0;
 888         }
 889
 890         if (!ctx->cipher->ctx_set_params(ctx->provctx, params))
 891             return 0;
 892     }
 893
 894     return 1;
 895 }
 896
 897 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 898 {
 899     int ret;
 900
 901     if (!ctx->cipher) {
 902         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 903         return 0;
 904     }
 905
 906     if (!ctx->cipher->ctrl) {
 907         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 908         return 0;
 909     }
 910
 911     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 912     if (ret == -1) {
 913         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 914                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 915         return 0;
 916     }
 917     return ret;
 918 }
 919
 920 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 921 {
 922     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 923         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 924     if (RAND_priv_bytes(key, ctx->key_len) <= 0)
 925         return 0;
 926     return 1;
 927 }
 928
 929 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 930 {
 931     if ((in == NULL) || (in->cipher == NULL)) {
 932         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 933         return 0;
 934     }
 935
 936     if (in->cipher->prov == NULL)
 937         goto legacy;
 938
 939     if (in->cipher->dupctx == NULL) {
 940         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 941         return 0;
 942     }
 943
 944     EVP_CIPHER_CTX_reset(out);
 945
 946     *out = *in;
 947     out->provctx = NULL;
 948
 949     if (in->fetched_cipher != NULL && !EVP_CIPHER_upref(in->fetched_cipher)) {
 950         out->fetched_cipher = NULL;
 951         return 0;
 952     }
 953
 954     out->provctx = in->cipher->dupctx(in->provctx);
 955     if (out->provctx == NULL) {
 956         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 957         return 0;
 958     }
 959
 960     return 1;
 961
 962     /* TODO(3.0): Remove legacy code below */
 963  legacy:
 964
 965 #ifndef OPENSSL_NO_ENGINE
 966     /* Make sure it's safe to copy a cipher context using an ENGINE */
 967     if (in->engine && !ENGINE_init(in->engine)) {
 968         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
 969         return 0;
 970     }
 971 #endif
 972
 973     EVP_CIPHER_CTX_reset(out);
 974     memcpy(out, in, sizeof(*out));
 975
 976     if (in->cipher_data && in->cipher->ctx_size) {
 977         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
 978         if (out->cipher_data == NULL) {
 979             out->cipher = NULL;
 980             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
 981             return 0;
 982         }
 983         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
 984     }
 985
 986     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
 987         if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
 988             out->cipher = NULL;
 989             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
 990             return 0;
 991         }
 992     return 1;
 993 }
 994
 995 static void *evp_cipher_from_dispatch(int nid, const OSSL_DISPATCH *fns,
 996                                       OSSL_PROVIDER *prov)
 997 {
 998     EVP_CIPHER *cipher = NULL;
 999     int fnciphcnt = 0, fnctxcnt = 0;
1000
1001     if ((cipher = EVP_CIPHER_meth_new(nid, 0, 0)) == NULL)
1002         return NULL;
1003
1004     for (; fns->function_id != 0; fns++) {
1005         switch (fns->function_id) {
1006         case OSSL_FUNC_CIPHER_NEWCTX:
1007             if (cipher->newctx != NULL)
1008                 break;
1009             cipher->newctx = OSSL_get_OP_cipher_newctx(fns);
1010             fnctxcnt++;
1011             break;
1012         case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
1013             if (cipher->einit != NULL)
1014                 break;
1015             cipher->einit = OSSL_get_OP_cipher_encrypt_init(fns);
1016             fnciphcnt++;
1017             break;
1018         case OSSL_FUNC_CIPHER_DECRYPT_INIT:
1019             if (cipher->dinit != NULL)
1020                 break;
1021             cipher->dinit = OSSL_get_OP_cipher_decrypt_init(fns);
1022             fnciphcnt++;
1023             break;
1024         case OSSL_FUNC_CIPHER_UPDATE:
1025             if (cipher->cupdate != NULL)
1026                 break;
1027             cipher->cupdate = OSSL_get_OP_cipher_update(fns);
1028             fnciphcnt++;
1029             break;
1030         case OSSL_FUNC_CIPHER_FINAL:
1031             if (cipher->cfinal != NULL)
1032                 break;
1033             cipher->cfinal = OSSL_get_OP_cipher_final(fns);
1034             fnciphcnt++;
1035             break;
1036         case OSSL_FUNC_CIPHER_CIPHER:
1037             if (cipher->ccipher != NULL)
1038                 break;
1039             cipher->ccipher = OSSL_get_OP_cipher_cipher(fns);
1040             break;
1041         case OSSL_FUNC_CIPHER_FREECTX:
1042             if (cipher->freectx != NULL)
1043                 break;
1044             cipher->freectx = OSSL_get_OP_cipher_freectx(fns);
1045             fnctxcnt++;
1046             break;
1047         case OSSL_FUNC_CIPHER_DUPCTX:
1048             if (cipher->dupctx != NULL)
1049                 break;
1050             cipher->dupctx = OSSL_get_OP_cipher_dupctx(fns);
1051             break;
1052         case OSSL_FUNC_CIPHER_KEY_LENGTH:
1053             if (cipher->key_length != NULL)
1054                 break;
1055             cipher->key_length = OSSL_get_OP_cipher_key_length(fns);
1056             break;
1057         case OSSL_FUNC_CIPHER_IV_LENGTH:
1058             if (cipher->iv_length != NULL)
1059                 break;
1060             cipher->iv_length = OSSL_get_OP_cipher_iv_length(fns);
1061             break;
1062         case OSSL_FUNC_CIPHER_BLOCK_SIZE:
1063             if (cipher->blocksize != NULL)
1064                 break;
1065             cipher->blocksize = OSSL_get_OP_cipher_block_size(fns);
1066             break;
1067         case OSSL_FUNC_CIPHER_GET_PARAMS:
1068             if (cipher->get_params != NULL)
1069                 break;
1070             cipher->get_params = OSSL_get_OP_cipher_get_params(fns);
1071             break;
1072         case OSSL_FUNC_CIPHER_CTX_GET_PARAMS:
1073             if (cipher->ctx_get_params != NULL)
1074                 break;
1075             cipher->ctx_get_params = OSSL_get_OP_cipher_ctx_get_params(fns);
1076             break;
1077         case OSSL_FUNC_CIPHER_CTX_SET_PARAMS:
1078             if (cipher->ctx_set_params != NULL)
1079                 break;
1080             cipher->ctx_set_params = OSSL_get_OP_cipher_ctx_set_params(fns);
1081             break;
1082         }
1083     }
1084     if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
1085             || (fnciphcnt == 0 && cipher->ccipher == NULL)
1086             || fnctxcnt != 2) {
1087         /*
1088          * In order to be a consistent set of functions we must have at least
1089          * a complete set of "encrypt" functions, or a complete set of "decrypt"
1090          * functions, or a single "cipher" function. In all cases we need a
1091          * complete set of context management functions
1092          */
1093         EVP_CIPHER_meth_free(cipher);
1094         EVPerr(EVP_F_EVP_CIPHER_FROM_DISPATCH, EVP_R_INVALID_PROVIDER_FUNCTIONS);
1095         return NULL;
1096     }
1097     cipher->prov = prov;
1098     if (prov != NULL)
1099         ossl_provider_upref(prov);
1100
1101     return cipher;
1102 }
1103
1104 static int evp_cipher_upref(void *cipher)
1105 {
1106     return EVP_CIPHER_upref(cipher);
1107 }
1108
1109 static void evp_cipher_free(void *cipher)
1110 {
1111     EVP_CIPHER_meth_free(cipher);
1112 }
1113
1114 static int evp_cipher_nid(void *vcipher)
1115 {
1116     EVP_CIPHER *cipher = vcipher;
1117
1118     return cipher->nid;
1119 }
1120
1121 EVP_CIPHER *EVP_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
1122                              const char *properties)
1123 {
1124     return evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
1125                              evp_cipher_from_dispatch, evp_cipher_upref,
1126                              evp_cipher_free, evp_cipher_nid);
1127 }