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,
 245                                   key,
 246                                   EVP_CIPHER_CTX_key_length(ctx),
 247                                   iv,
 248                                   EVP_CIPHER_CTX_iv_length(ctx));
 249     }
 250
 251     if (ctx->cipher->dinit == NULL) {
 252         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 253         return 0;
 254     }
 255
 256     return ctx->cipher->dinit(ctx->provctx,
 257                               key,
 258                               EVP_CIPHER_CTX_key_length(ctx),
 259                               iv,
 260                               EVP_CIPHER_CTX_iv_length(ctx));
 261
 262     /* TODO(3.0): Remove legacy code below */
 263  legacy:
 264
 265     if (cipher != NULL) {
 266         /*
 267          * Ensure a context left lying around from last time is cleared (we
 268          * previously attempted to avoid this if the same ENGINE and
 269          * EVP_CIPHER could be used).
 270          */
 271         if (ctx->cipher) {
 272             unsigned long flags = ctx->flags;
 273             EVP_CIPHER_CTX_reset(ctx);
 274             /* Restore encrypt and flags */
 275             ctx->encrypt = enc;
 276             ctx->flags = flags;
 277         }
 278 #ifndef OPENSSL_NO_ENGINE
 279         if (impl != NULL) {
 280             if (!ENGINE_init(impl)) {
 281                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 282                 return 0;
 283             }
 284         } else {
 285             impl = tmpimpl;
 286         }
 287         if (impl != NULL) {
 288             /* There's an ENGINE for this job ... (apparently) */
 289             const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 290
 291             if (c == NULL) {
 292                 /*
 293                  * One positive side-effect of US's export control history,
 294                  * is that we should at least be able to avoid using US
 295                  * misspellings of "initialisation"?
 296                  */
 297                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 298                 return 0;
 299             }
 300             /* We'll use the ENGINE's private cipher definition */
 301             cipher = c;
 302             /*
 303              * Store the ENGINE functional reference so we know 'cipher' came
 304              * from an ENGINE and we need to release it when done.
 305              */
 306             ctx->engine = impl;
 307         } else {
 308             ctx->engine = NULL;
 309         }
 310 #endif
 311
 312         ctx->cipher = cipher;
 313         if (ctx->cipher->ctx_size) {
 314             ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
 315             if (ctx->cipher_data == NULL) {
 316                 ctx->cipher = NULL;
 317                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 318                 return 0;
 319             }
 320         } else {
 321             ctx->cipher_data = NULL;
 322         }
 323         ctx->key_len = cipher->key_len;
 324         /* Preserve wrap enable flag, zero everything else */
 325         ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
 326         if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 327             if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 328                 ctx->cipher = NULL;
 329                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 330                 return 0;
 331             }
 332         }
 333     }
 334 #ifndef OPENSSL_NO_ENGINE
 335  skip_to_init:
 336 #endif
 337     /* we assume block size is a power of 2 in *cryptUpdate */
 338     OPENSSL_assert(ctx->cipher->block_size == 1
 339                    || ctx->cipher->block_size == 8
 340                    || ctx->cipher->block_size == 16);
 341
 342     if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
 343         && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
 344         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
 345         return 0;
 346     }
 347
 348     if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
 349         switch (EVP_CIPHER_CTX_mode(ctx)) {
 350
 351         case EVP_CIPH_STREAM_CIPHER:
 352         case EVP_CIPH_ECB_MODE:
 353             break;
 354
 355         case EVP_CIPH_CFB_MODE:
 356         case EVP_CIPH_OFB_MODE:
 357
 358             ctx->num = 0;
 359             /* fall-through */
 360
 361         case EVP_CIPH_CBC_MODE:
 362
 363             OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 364                            (int)sizeof(ctx->iv));
 365             if (iv)
 366                 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 367             memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 368             break;
 369
 370         case EVP_CIPH_CTR_MODE:
 371             ctx->num = 0;
 372             /* Don't reuse IV for CTR mode */
 373             if (iv)
 374                 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 375             break;
 376
 377         default:
 378             return 0;
 379         }
 380     }
 381
 382     if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 383         if (!ctx->cipher->init(ctx, key, iv, enc))
 384             return 0;
 385     }
 386     ctx->buf_len = 0;
 387     ctx->final_used = 0;
 388     ctx->block_mask = ctx->cipher->block_size - 1;
 389     return 1;
 390 }
 391
 392 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 393                      const unsigned char *in, int inl)
 394 {
 395     if (ctx->encrypt)
 396         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 397     else
 398         return EVP_DecryptUpdate(ctx, out, outl, in, inl);
 399 }
 400
 401 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 402 {
 403     if (ctx->encrypt)
 404         return EVP_EncryptFinal_ex(ctx, out, outl);
 405     else
 406         return EVP_DecryptFinal_ex(ctx, out, outl);
 407 }
 408
 409 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 410 {
 411     if (ctx->encrypt)
 412         return EVP_EncryptFinal(ctx, out, outl);
 413     else
 414         return EVP_DecryptFinal(ctx, out, outl);
 415 }
 416
 417 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 418                     const unsigned char *key, const unsigned char *iv)
 419 {
 420     return EVP_CipherInit(ctx, cipher, key, iv, 1);
 421 }
 422
 423 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 424                        ENGINE *impl, const unsigned char *key,
 425                        const unsigned char *iv)
 426 {
 427     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 428 }
 429
 430 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 431                     const unsigned char *key, const unsigned char *iv)
 432 {
 433     return EVP_CipherInit(ctx, cipher, key, iv, 0);
 434 }
 435
 436 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 437                        ENGINE *impl, const unsigned char *key,
 438                        const unsigned char *iv)
 439 {
 440     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 441 }
 442
 443 /*
 444  * According to the letter of standard difference between pointers
 445  * is specified to be valid only within same object. This makes
 446  * it formally challenging to determine if input and output buffers
 447  * are not partially overlapping with standard pointer arithmetic.
 448  */
 449 #ifdef PTRDIFF_T
 450 # undef PTRDIFF_T
 451 #endif
 452 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
 453 /*
 454  * Then we have VMS that distinguishes itself by adhering to
 455  * sizeof(size_t)==4 even in 64-bit builds, which means that
 456  * difference between two pointers might be truncated to 32 bits.
 457  * In the context one can even wonder how comparison for
 458  * equality is implemented. To be on the safe side we adhere to
 459  * PTRDIFF_T even for comparison for equality.
 460  */
 461 # define PTRDIFF_T uint64_t
 462 #else
 463 # define PTRDIFF_T size_t
 464 #endif
 465
 466 int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
 467 {
 468     PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
 469     /*
 470      * Check for partially overlapping buffers. [Binary logical
 471      * operations are used instead of boolean to minimize number
 472      * of conditional branches.]
 473      */
 474     int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
 475                                                 (diff > (0 - (PTRDIFF_T)len)));
 476
 477     return overlapped;
 478 }
 479
 480 static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
 481                                     unsigned char *out, int *outl,
 482                                     const unsigned char *in, int inl)
 483 {
 484     int i, j, bl, cmpl = inl;
 485
 486     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 487         cmpl = (cmpl + 7) / 8;
 488
 489     bl = ctx->cipher->block_size;
 490
 491     if (inl <= 0) {
 492         *outl = 0;
 493         return inl == 0;
 494     }
 495
 496     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 497         /* If block size > 1 then the cipher will have to do this check */
 498         if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
 499             EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 500             return 0;
 501         }
 502
 503         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 504         if (i < 0)
 505             return 0;
 506         else
 507             *outl = i;
 508         return 1;
 509     }
 510
 511     if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
 512         EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 513         return 0;
 514     }
 515
 516     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 517         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 518             *outl = inl;
 519             return 1;
 520         } else {
 521             *outl = 0;
 522             return 0;
 523         }
 524     }
 525     i = ctx->buf_len;
 526     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 527     if (i != 0) {
 528         if (bl - i > inl) {
 529             memcpy(&(ctx->buf[i]), in, inl);
 530             ctx->buf_len += inl;
 531             *outl = 0;
 532             return 1;
 533         } else {
 534             j = bl - i;
 535             memcpy(&(ctx->buf[i]), in, j);
 536             inl -= j;
 537             in += j;
 538             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 539                 return 0;
 540             out += bl;
 541             *outl = bl;
 542         }
 543     } else
 544         *outl = 0;
 545     i = inl & (bl - 1);
 546     inl -= i;
 547     if (inl > 0) {
 548         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 549             return 0;
 550         *outl += inl;
 551     }
 552
 553     if (i != 0)
 554         memcpy(ctx->buf, &(in[inl]), i);
 555     ctx->buf_len = i;
 556     return 1;
 557 }
 558
 559
 560 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 561                       const unsigned char *in, int inl)
 562 {
 563     int ret;
 564     size_t soutl;
 565
 566     /* Prevent accidental use of decryption context when encrypting */
 567     if (!ctx->encrypt) {
 568         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
 569         return 0;
 570     }
 571
 572     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 573         goto legacy;
 574
 575     if (ctx->cipher->cupdate == NULL) {
 576         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 577         return 0;
 578     }
 579     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl, in, (size_t)inl);
 580
 581     if (soutl > INT_MAX) {
 582         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 583         return 0;
 584     }
 585     *outl = soutl;
 586     return ret;
 587
 588     /* TODO(3.0): Remove legacy code below */
 589  legacy:
 590
 591     return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 592 }
 593
 594 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 595 {
 596     int ret;
 597     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 598     return ret;
 599 }
 600
 601 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 602 {
 603     int n, ret;
 604     unsigned int i, b, bl;
 605     size_t soutl;
 606
 607     /* Prevent accidental use of decryption context when encrypting */
 608     if (!ctx->encrypt) {
 609         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 610         return 0;
 611     }
 612
 613     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 614         goto legacy;
 615
 616     if (ctx->cipher->cfinal == NULL) {
 617         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 618         return 0;
 619     }
 620
 621     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl);
 622
 623     if (soutl > INT_MAX) {
 624         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 625         return 0;
 626     }
 627     *outl = soutl;
 628
 629     return ret;
 630
 631     /* TODO(3.0): Remove legacy code below */
 632  legacy:
 633
 634     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 635         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 636         if (ret < 0)
 637             return 0;
 638         else
 639             *outl = ret;
 640         return 1;
 641     }
 642
 643     b = ctx->cipher->block_size;
 644     OPENSSL_assert(b <= sizeof(ctx->buf));
 645     if (b == 1) {
 646         *outl = 0;
 647         return 1;
 648     }
 649     bl = ctx->buf_len;
 650     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 651         if (bl) {
 652             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 653                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 654             return 0;
 655         }
 656         *outl = 0;
 657         return 1;
 658     }
 659
 660     n = b - bl;
 661     for (i = bl; i < b; i++)
 662         ctx->buf[i] = n;
 663     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 664
 665     if (ret)
 666         *outl = b;
 667
 668     return ret;
 669 }
 670
 671 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 672                       const unsigned char *in, int inl)
 673 {
 674     int fix_len, cmpl = inl, ret;
 675     unsigned int b;
 676     size_t soutl;
 677
 678     /* Prevent accidental use of encryption context when decrypting */
 679     if (ctx->encrypt) {
 680         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
 681         return 0;
 682     }
 683
 684     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 685         goto legacy;
 686
 687     if (ctx->cipher->cupdate == NULL) {
 688         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 689         return 0;
 690     }
 691     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl, in, (size_t)inl);
 692
 693     if (ret) {
 694         if (soutl > INT_MAX) {
 695             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 696             return 0;
 697         }
 698         *outl = soutl;
 699     }
 700
 701     return ret;
 702
 703     /* TODO(3.0): Remove legacy code below */
 704  legacy:
 705
 706     b = ctx->cipher->block_size;
 707
 708     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 709         cmpl = (cmpl + 7) / 8;
 710
 711     if (inl <= 0) {
 712         *outl = 0;
 713         return inl == 0;
 714     }
 715
 716     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 717         if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
 718             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 719             return 0;
 720         }
 721
 722         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 723         if (fix_len < 0) {
 724             *outl = 0;
 725             return 0;
 726         } else
 727             *outl = fix_len;
 728         return 1;
 729     }
 730
 731     if (ctx->flags & EVP_CIPH_NO_PADDING)
 732         return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 733
 734     OPENSSL_assert(b <= sizeof(ctx->final));
 735
 736     if (ctx->final_used) {
 737         /* see comment about PTRDIFF_T comparison above */
 738         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
 739             || is_partially_overlapping(out, in, b)) {
 740             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 741             return 0;
 742         }
 743         memcpy(out, ctx->final, b);
 744         out += b;
 745         fix_len = 1;
 746     } else
 747         fix_len = 0;
 748
 749     if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
 750         return 0;
 751
 752     /*
 753      * if we have 'decrypted' a multiple of block size, make sure we have a
 754      * copy of this last block
 755      */
 756     if (b > 1 && !ctx->buf_len) {
 757         *outl -= b;
 758         ctx->final_used = 1;
 759         memcpy(ctx->final, &out[*outl], b);
 760     } else
 761         ctx->final_used = 0;
 762
 763     if (fix_len)
 764         *outl += b;
 765
 766     return 1;
 767 }
 768
 769 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 770 {
 771     int ret;
 772     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 773     return ret;
 774 }
 775
 776 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 777 {
 778     int i, n;
 779     unsigned int b;
 780     size_t soutl;
 781     int ret;
 782
 783     /* Prevent accidental use of encryption context when decrypting */
 784     if (ctx->encrypt) {
 785         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 786         return 0;
 787     }
 788
 789     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 790         goto legacy;
 791
 792     if (ctx->cipher->cfinal == NULL) {
 793         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 794         return 0;
 795     }
 796
 797     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl);
 798
 799     if (ret) {
 800         if (soutl > INT_MAX) {
 801             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 802             return 0;
 803         }
 804         *outl = soutl;
 805     }
 806
 807     return ret;
 808
 809     /* TODO(3.0): Remove legacy code below */
 810  legacy:
 811
 812     *outl = 0;
 813
 814     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 815         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 816         if (i < 0)
 817             return 0;
 818         else
 819             *outl = i;
 820         return 1;
 821     }
 822
 823     b = ctx->cipher->block_size;
 824     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 825         if (ctx->buf_len) {
 826             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 827                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 828             return 0;
 829         }
 830         *outl = 0;
 831         return 1;
 832     }
 833     if (b > 1) {
 834         if (ctx->buf_len || !ctx->final_used) {
 835             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 836             return 0;
 837         }
 838         OPENSSL_assert(b <= sizeof(ctx->final));
 839
 840         /*
 841          * The following assumes that the ciphertext has been authenticated.
 842          * Otherwise it provides a padding oracle.
 843          */
 844         n = ctx->final[b - 1];
 845         if (n == 0 || n > (int)b) {
 846             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 847             return 0;
 848         }
 849         for (i = 0; i < n; i++) {
 850             if (ctx->final[--b] != n) {
 851                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 852                 return 0;
 853             }
 854         }
 855         n = ctx->cipher->block_size - n;
 856         for (i = 0; i < n; i++)
 857             out[i] = ctx->final[i];
 858         *outl = n;
 859     } else
 860         *outl = 0;
 861     return 1;
 862 }
 863
 864 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 865 {
 866     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 867         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 868     if (EVP_CIPHER_CTX_key_length(c) == keylen)
 869         return 1;
 870     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 871         c->key_len = keylen;
 872         return 1;
 873     }
 874     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 875     return 0;
 876 }
 877
 878 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 879 {
 880     if (pad)
 881         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 882     else
 883         ctx->flags |= EVP_CIPH_NO_PADDING;
 884
 885     if (ctx->cipher != NULL && ctx->cipher->prov != NULL) {
 886         OSSL_PARAM params[] = {
 887             OSSL_PARAM_int(OSSL_CIPHER_PARAM_PADDING, NULL),
 888             OSSL_PARAM_END
 889         };
 890
 891         params[0].data = &pad;
 892
 893         if (ctx->cipher->ctx_set_params == NULL) {
 894             EVPerr(EVP_F_EVP_CIPHER_CTX_SET_PADDING, EVP_R_CTRL_NOT_IMPLEMENTED);
 895             return 0;
 896         }
 897
 898         if (!ctx->cipher->ctx_set_params(ctx->provctx, params))
 899             return 0;
 900     }
 901
 902     return 1;
 903 }
 904
 905 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 906 {
 907     int ret;
 908
 909     if (!ctx->cipher) {
 910         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 911         return 0;
 912     }
 913
 914     if (!ctx->cipher->ctrl) {
 915         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 916         return 0;
 917     }
 918
 919     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 920     if (ret == -1) {
 921         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 922                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 923         return 0;
 924     }
 925     return ret;
 926 }
 927
 928 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 929 {
 930     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 931         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 932     if (RAND_priv_bytes(key, ctx->key_len) <= 0)
 933         return 0;
 934     return 1;
 935 }
 936
 937 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 938 {
 939     if ((in == NULL) || (in->cipher == NULL)) {
 940         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 941         return 0;
 942     }
 943
 944     if (in->cipher->prov == NULL)
 945         goto legacy;
 946
 947     if (in->cipher->dupctx == NULL) {
 948         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 949         return 0;
 950     }
 951
 952     EVP_CIPHER_CTX_reset(out);
 953
 954     *out = *in;
 955     out->provctx = NULL;
 956
 957     if (in->fetched_cipher != NULL && !EVP_CIPHER_upref(in->fetched_cipher)) {
 958         out->fetched_cipher = NULL;
 959         return 0;
 960     }
 961
 962     out->provctx = in->cipher->dupctx(in->provctx);
 963     if (out->provctx == NULL) {
 964         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 965         return 0;
 966     }
 967
 968     return 1;
 969
 970     /* TODO(3.0): Remove legacy code below */
 971  legacy:
 972
 973 #ifndef OPENSSL_NO_ENGINE
 974     /* Make sure it's safe to copy a cipher context using an ENGINE */
 975     if (in->engine && !ENGINE_init(in->engine)) {
 976         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
 977         return 0;
 978     }
 979 #endif
 980
 981     EVP_CIPHER_CTX_reset(out);
 982     memcpy(out, in, sizeof(*out));
 983
 984     if (in->cipher_data && in->cipher->ctx_size) {
 985         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
 986         if (out->cipher_data == NULL) {
 987             out->cipher = NULL;
 988             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
 989             return 0;
 990         }
 991         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
 992     }
 993
 994     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
 995         if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
 996             out->cipher = NULL;
 997             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
 998             return 0;
 999         }
1000     return 1;
1001 }
1002
1003 static void *evp_cipher_from_dispatch(int nid, const OSSL_DISPATCH *fns,
1004                                       OSSL_PROVIDER *prov)
1005 {
1006     EVP_CIPHER *cipher = NULL;
1007     int fnciphcnt = 0, fnctxcnt = 0;
1008
1009     if ((cipher = EVP_CIPHER_meth_new(nid, 0, 0)) == NULL)
1010         return NULL;
1011
1012     for (; fns->function_id != 0; fns++) {
1013         switch (fns->function_id) {
1014         case OSSL_FUNC_CIPHER_NEWCTX:
1015             if (cipher->newctx != NULL)
1016                 break;
1017             cipher->newctx = OSSL_get_OP_cipher_newctx(fns);
1018             fnctxcnt++;
1019             break;
1020         case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
1021             if (cipher->einit != NULL)
1022                 break;
1023             cipher->einit = OSSL_get_OP_cipher_encrypt_init(fns);
1024             fnciphcnt++;
1025             break;
1026         case OSSL_FUNC_CIPHER_DECRYPT_INIT:
1027             if (cipher->dinit != NULL)
1028                 break;
1029             cipher->dinit = OSSL_get_OP_cipher_decrypt_init(fns);
1030             fnciphcnt++;
1031             break;
1032         case OSSL_FUNC_CIPHER_UPDATE:
1033             if (cipher->cupdate != NULL)
1034                 break;
1035             cipher->cupdate = OSSL_get_OP_cipher_update(fns);
1036             fnciphcnt++;
1037             break;
1038         case OSSL_FUNC_CIPHER_FINAL:
1039             if (cipher->cfinal != NULL)
1040                 break;
1041             cipher->cfinal = OSSL_get_OP_cipher_final(fns);
1042             fnciphcnt++;
1043             break;
1044         case OSSL_FUNC_CIPHER_CIPHER:
1045             if (cipher->ccipher != NULL)
1046                 break;
1047             cipher->ccipher = OSSL_get_OP_cipher_cipher(fns);
1048             break;
1049         case OSSL_FUNC_CIPHER_FREECTX:
1050             if (cipher->freectx != NULL)
1051                 break;
1052             cipher->freectx = OSSL_get_OP_cipher_freectx(fns);
1053             fnctxcnt++;
1054             break;
1055         case OSSL_FUNC_CIPHER_DUPCTX:
1056             if (cipher->dupctx != NULL)
1057                 break;
1058             cipher->dupctx = OSSL_get_OP_cipher_dupctx(fns);
1059             break;
1060         case OSSL_FUNC_CIPHER_KEY_LENGTH:
1061             if (cipher->key_length != NULL)
1062                 break;
1063             cipher->key_length = OSSL_get_OP_cipher_key_length(fns);
1064             break;
1065         case OSSL_FUNC_CIPHER_IV_LENGTH:
1066             if (cipher->iv_length != NULL)
1067                 break;
1068             cipher->iv_length = OSSL_get_OP_cipher_iv_length(fns);
1069             break;
1070         case OSSL_FUNC_CIPHER_BLOCK_SIZE:
1071             if (cipher->blocksize != NULL)
1072                 break;
1073             cipher->blocksize = OSSL_get_OP_cipher_block_size(fns);
1074             break;
1075         case OSSL_FUNC_CIPHER_GET_PARAMS:
1076             if (cipher->get_params != NULL)
1077                 break;
1078             cipher->get_params = OSSL_get_OP_cipher_get_params(fns);
1079             break;
1080         case OSSL_FUNC_CIPHER_CTX_GET_PARAMS:
1081             if (cipher->ctx_get_params != NULL)
1082                 break;
1083             cipher->ctx_get_params = OSSL_get_OP_cipher_ctx_get_params(fns);
1084             break;
1085         case OSSL_FUNC_CIPHER_CTX_SET_PARAMS:
1086             if (cipher->ctx_set_params != NULL)
1087                 break;
1088             cipher->ctx_set_params = OSSL_get_OP_cipher_ctx_set_params(fns);
1089             break;
1090         }
1091     }
1092     if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
1093             || (fnciphcnt == 0 && cipher->ccipher == NULL)
1094             || fnctxcnt != 2) {
1095         /*
1096          * In order to be a consistent set of functions we must have at least
1097          * a complete set of "encrypt" functions, or a complete set of "decrypt"
1098          * functions, or a single "cipher" function. In all cases we need a
1099          * complete set of context management functions
1100          */
1101         EVP_CIPHER_meth_free(cipher);
1102         EVPerr(EVP_F_EVP_CIPHER_FROM_DISPATCH, EVP_R_INVALID_PROVIDER_FUNCTIONS);
1103         return NULL;
1104     }
1105     cipher->prov = prov;
1106     if (prov != NULL)
1107         ossl_provider_upref(prov);
1108
1109     return cipher;
1110 }
1111
1112 static int evp_cipher_upref(void *cipher)
1113 {
1114     return EVP_CIPHER_upref(cipher);
1115 }
1116
1117 static void evp_cipher_free(void *cipher)
1118 {
1119     EVP_CIPHER_meth_free(cipher);
1120 }
1121
1122 static int evp_cipher_nid(void *vcipher)
1123 {
1124     EVP_CIPHER *cipher = vcipher;
1125
1126     return cipher->nid;
1127 }
1128
1129 EVP_CIPHER *EVP_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
1130                              const char *properties)
1131 {
1132     return evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
1133                              evp_cipher_from_dispatch, evp_cipher_upref,
1134                              evp_cipher_free, evp_cipher_nid);
1135 }