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(ossl_provider_ctx(cipher->prov));
 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                                   key == NULL ? 0
 247                                               : EVP_CIPHER_CTX_key_length(ctx),
 248                                   iv,
 249                                   iv == NULL ? 0
 250                                              : EVP_CIPHER_CTX_iv_length(ctx));
 251     }
 252
 253     if (ctx->cipher->dinit == NULL) {
 254         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 255         return 0;
 256     }
 257
 258     return ctx->cipher->dinit(ctx->provctx,
 259                               key,
 260                               key == NULL ? 0
 261                                           : EVP_CIPHER_CTX_key_length(ctx),
 262                               iv,
 263                               iv == NULL ? 0
 264                                          : EVP_CIPHER_CTX_iv_length(ctx));
 265
 266     /* TODO(3.0): Remove legacy code below */
 267  legacy:
 268
 269     if (cipher != NULL) {
 270         /*
 271          * Ensure a context left lying around from last time is cleared (we
 272          * previously attempted to avoid this if the same ENGINE and
 273          * EVP_CIPHER could be used).
 274          */
 275         if (ctx->cipher) {
 276             unsigned long flags = ctx->flags;
 277             EVP_CIPHER_CTX_reset(ctx);
 278             /* Restore encrypt and flags */
 279             ctx->encrypt = enc;
 280             ctx->flags = flags;
 281         }
 282 #ifndef OPENSSL_NO_ENGINE
 283         if (impl != NULL) {
 284             if (!ENGINE_init(impl)) {
 285                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 286                 return 0;
 287             }
 288         } else {
 289             impl = tmpimpl;
 290         }
 291         if (impl != NULL) {
 292             /* There's an ENGINE for this job ... (apparently) */
 293             const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
 294
 295             if (c == NULL) {
 296                 /*
 297                  * One positive side-effect of US's export control history,
 298                  * is that we should at least be able to avoid using US
 299                  * misspellings of "initialisation"?
 300                  */
 301                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 302                 return 0;
 303             }
 304             /* We'll use the ENGINE's private cipher definition */
 305             cipher = c;
 306             /*
 307              * Store the ENGINE functional reference so we know 'cipher' came
 308              * from an ENGINE and we need to release it when done.
 309              */
 310             ctx->engine = impl;
 311         } else {
 312             ctx->engine = NULL;
 313         }
 314 #endif
 315
 316         ctx->cipher = cipher;
 317         if (ctx->cipher->ctx_size) {
 318             ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
 319             if (ctx->cipher_data == NULL) {
 320                 ctx->cipher = NULL;
 321                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
 322                 return 0;
 323             }
 324         } else {
 325             ctx->cipher_data = NULL;
 326         }
 327         ctx->key_len = cipher->key_len;
 328         /* Preserve wrap enable flag, zero everything else */
 329         ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
 330         if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 331             if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 332                 ctx->cipher = NULL;
 333                 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
 334                 return 0;
 335             }
 336         }
 337     }
 338 #ifndef OPENSSL_NO_ENGINE
 339  skip_to_init:
 340 #endif
 341     if (ctx->cipher == NULL)
 342         return 0;
 343
 344     /* we assume block size is a power of 2 in *cryptUpdate */
 345     OPENSSL_assert(ctx->cipher->block_size == 1
 346                    || ctx->cipher->block_size == 8
 347                    || ctx->cipher->block_size == 16);
 348
 349     if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
 350         && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
 351         EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
 352         return 0;
 353     }
 354
 355     if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
 356         switch (EVP_CIPHER_CTX_mode(ctx)) {
 357
 358         case EVP_CIPH_STREAM_CIPHER:
 359         case EVP_CIPH_ECB_MODE:
 360             break;
 361
 362         case EVP_CIPH_CFB_MODE:
 363         case EVP_CIPH_OFB_MODE:
 364
 365             ctx->num = 0;
 366             /* fall-through */
 367
 368         case EVP_CIPH_CBC_MODE:
 369
 370             OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
 371                            (int)sizeof(ctx->iv));
 372             if (iv)
 373                 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 374             memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 375             break;
 376
 377         case EVP_CIPH_CTR_MODE:
 378             ctx->num = 0;
 379             /* Don't reuse IV for CTR mode */
 380             if (iv)
 381                 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 382             break;
 383
 384         default:
 385             return 0;
 386         }
 387     }
 388
 389     if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 390         if (!ctx->cipher->init(ctx, key, iv, enc))
 391             return 0;
 392     }
 393     ctx->buf_len = 0;
 394     ctx->final_used = 0;
 395     ctx->block_mask = ctx->cipher->block_size - 1;
 396     return 1;
 397 }
 398
 399 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 400                      const unsigned char *in, int inl)
 401 {
 402     if (ctx->encrypt)
 403         return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 404     else
 405         return EVP_DecryptUpdate(ctx, out, outl, in, inl);
 406 }
 407
 408 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 409 {
 410     if (ctx->encrypt)
 411         return EVP_EncryptFinal_ex(ctx, out, outl);
 412     else
 413         return EVP_DecryptFinal_ex(ctx, out, outl);
 414 }
 415
 416 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 417 {
 418     if (ctx->encrypt)
 419         return EVP_EncryptFinal(ctx, out, outl);
 420     else
 421         return EVP_DecryptFinal(ctx, out, outl);
 422 }
 423
 424 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 425                     const unsigned char *key, const unsigned char *iv)
 426 {
 427     return EVP_CipherInit(ctx, cipher, key, iv, 1);
 428 }
 429
 430 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 431                        ENGINE *impl, const unsigned char *key,
 432                        const unsigned char *iv)
 433 {
 434     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
 435 }
 436
 437 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 438                     const unsigned char *key, const unsigned char *iv)
 439 {
 440     return EVP_CipherInit(ctx, cipher, key, iv, 0);
 441 }
 442
 443 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 444                        ENGINE *impl, const unsigned char *key,
 445                        const unsigned char *iv)
 446 {
 447     return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
 448 }
 449
 450 /*
 451  * According to the letter of standard difference between pointers
 452  * is specified to be valid only within same object. This makes
 453  * it formally challenging to determine if input and output buffers
 454  * are not partially overlapping with standard pointer arithmetic.
 455  */
 456 #ifdef PTRDIFF_T
 457 # undef PTRDIFF_T
 458 #endif
 459 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
 460 /*
 461  * Then we have VMS that distinguishes itself by adhering to
 462  * sizeof(size_t)==4 even in 64-bit builds, which means that
 463  * difference between two pointers might be truncated to 32 bits.
 464  * In the context one can even wonder how comparison for
 465  * equality is implemented. To be on the safe side we adhere to
 466  * PTRDIFF_T even for comparison for equality.
 467  */
 468 # define PTRDIFF_T uint64_t
 469 #else
 470 # define PTRDIFF_T size_t
 471 #endif
 472
 473 int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
 474 {
 475     PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
 476     /*
 477      * Check for partially overlapping buffers. [Binary logical
 478      * operations are used instead of boolean to minimize number
 479      * of conditional branches.]
 480      */
 481     int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
 482                                                 (diff > (0 - (PTRDIFF_T)len)));
 483
 484     return overlapped;
 485 }
 486
 487 static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
 488                                     unsigned char *out, int *outl,
 489                                     const unsigned char *in, int inl)
 490 {
 491     int i, j, bl, cmpl = inl;
 492
 493     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 494         cmpl = (cmpl + 7) / 8;
 495
 496     bl = ctx->cipher->block_size;
 497
 498     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 499         /* If block size > 1 then the cipher will have to do this check */
 500         if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
 501             EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 502             return 0;
 503         }
 504
 505         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 506         if (i < 0)
 507             return 0;
 508         else
 509             *outl = i;
 510         return 1;
 511     }
 512
 513     if (inl <= 0) {
 514         *outl = 0;
 515         return inl == 0;
 516     }
 517     if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
 518         EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 519         return 0;
 520     }
 521
 522     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 523         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 524             *outl = inl;
 525             return 1;
 526         } else {
 527             *outl = 0;
 528             return 0;
 529         }
 530     }
 531     i = ctx->buf_len;
 532     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 533     if (i != 0) {
 534         if (bl - i > inl) {
 535             memcpy(&(ctx->buf[i]), in, inl);
 536             ctx->buf_len += inl;
 537             *outl = 0;
 538             return 1;
 539         } else {
 540             j = bl - i;
 541             memcpy(&(ctx->buf[i]), in, j);
 542             inl -= j;
 543             in += j;
 544             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 545                 return 0;
 546             out += bl;
 547             *outl = bl;
 548         }
 549     } else
 550         *outl = 0;
 551     i = inl & (bl - 1);
 552     inl -= i;
 553     if (inl > 0) {
 554         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 555             return 0;
 556         *outl += inl;
 557     }
 558
 559     if (i != 0)
 560         memcpy(ctx->buf, &(in[inl]), i);
 561     ctx->buf_len = i;
 562     return 1;
 563 }
 564
 565
 566 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 567                       const unsigned char *in, int inl)
 568 {
 569     int ret;
 570     size_t soutl;
 571     int blocksize;
 572
 573     /* Prevent accidental use of decryption context when encrypting */
 574     if (!ctx->encrypt) {
 575         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
 576         return 0;
 577     }
 578
 579     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 580         goto legacy;
 581
 582     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 583
 584     if (ctx->cipher->cupdate == NULL  || blocksize < 1) {
 585         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 586         return 0;
 587     }
 588     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
 589                                inl + (blocksize == 1 ? 0 : blocksize), in,
 590                                (size_t)inl);
 591
 592     if (ret) {
 593         if (soutl > INT_MAX) {
 594             EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 595             return 0;
 596         }
 597         *outl = soutl;
 598     }
 599
 600     return ret;
 601
 602     /* TODO(3.0): Remove legacy code below */
 603  legacy:
 604
 605     return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 606 }
 607
 608 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 609 {
 610     int ret;
 611     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 612     return ret;
 613 }
 614
 615 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 616 {
 617     int n, ret;
 618     unsigned int i, b, bl;
 619     size_t soutl;
 620     int blocksize;
 621
 622     /* Prevent accidental use of decryption context when encrypting */
 623     if (!ctx->encrypt) {
 624         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 625         return 0;
 626     }
 627
 628     if (ctx->cipher == NULL) {
 629         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_NO_CIPHER_SET);
 630         return 0;
 631     }
 632     if (ctx->cipher->prov == NULL)
 633         goto legacy;
 634
 635     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 636
 637     if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
 638         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 639         return 0;
 640     }
 641
 642     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
 643                               blocksize == 1 ? 0 : blocksize);
 644
 645     if (ret) {
 646         if (soutl > INT_MAX) {
 647             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 648             return 0;
 649         }
 650         *outl = soutl;
 651     }
 652
 653     return ret;
 654
 655     /* TODO(3.0): Remove legacy code below */
 656  legacy:
 657
 658     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 659         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 660         if (ret < 0)
 661             return 0;
 662         else
 663             *outl = ret;
 664         return 1;
 665     }
 666
 667     b = ctx->cipher->block_size;
 668     OPENSSL_assert(b <= sizeof(ctx->buf));
 669     if (b == 1) {
 670         *outl = 0;
 671         return 1;
 672     }
 673     bl = ctx->buf_len;
 674     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 675         if (bl) {
 676             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 677                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 678             return 0;
 679         }
 680         *outl = 0;
 681         return 1;
 682     }
 683
 684     n = b - bl;
 685     for (i = bl; i < b; i++)
 686         ctx->buf[i] = n;
 687     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 688
 689     if (ret)
 690         *outl = b;
 691
 692     return ret;
 693 }
 694
 695 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 696                       const unsigned char *in, int inl)
 697 {
 698     int fix_len, cmpl = inl, ret;
 699     unsigned int b;
 700     size_t soutl;
 701     int blocksize;
 702
 703     /* Prevent accidental use of encryption context when decrypting */
 704     if (ctx->encrypt) {
 705         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
 706         return 0;
 707     }
 708
 709     if (ctx->cipher == NULL) {
 710         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_NO_CIPHER_SET);
 711         return 0;
 712     }
 713     if (ctx->cipher->prov == NULL)
 714         goto legacy;
 715
 716     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 717
 718     if (ctx->cipher->cupdate == NULL || blocksize < 1) {
 719         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 720         return 0;
 721     }
 722     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
 723                                inl + (blocksize == 1 ? 0 : blocksize), in,
 724                                (size_t)inl);
 725
 726     if (ret) {
 727         if (soutl > INT_MAX) {
 728             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 729             return 0;
 730         }
 731         *outl = soutl;
 732     }
 733
 734     return ret;
 735
 736     /* TODO(3.0): Remove legacy code below */
 737  legacy:
 738
 739     b = ctx->cipher->block_size;
 740
 741     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 742         cmpl = (cmpl + 7) / 8;
 743
 744     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 745         if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
 746             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 747             return 0;
 748         }
 749
 750         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 751         if (fix_len < 0) {
 752             *outl = 0;
 753             return 0;
 754         } else
 755             *outl = fix_len;
 756         return 1;
 757     }
 758
 759     if (inl <= 0) {
 760         *outl = 0;
 761         return inl == 0;
 762     }
 763
 764     if (ctx->flags & EVP_CIPH_NO_PADDING)
 765         return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 766
 767     OPENSSL_assert(b <= sizeof(ctx->final));
 768
 769     if (ctx->final_used) {
 770         /* see comment about PTRDIFF_T comparison above */
 771         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
 772             || is_partially_overlapping(out, in, b)) {
 773             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 774             return 0;
 775         }
 776         memcpy(out, ctx->final, b);
 777         out += b;
 778         fix_len = 1;
 779     } else
 780         fix_len = 0;
 781
 782     if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
 783         return 0;
 784
 785     /*
 786      * if we have 'decrypted' a multiple of block size, make sure we have a
 787      * copy of this last block
 788      */
 789     if (b > 1 && !ctx->buf_len) {
 790         *outl -= b;
 791         ctx->final_used = 1;
 792         memcpy(ctx->final, &out[*outl], b);
 793     } else
 794         ctx->final_used = 0;
 795
 796     if (fix_len)
 797         *outl += b;
 798
 799     return 1;
 800 }
 801
 802 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 803 {
 804     int ret;
 805     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 806     return ret;
 807 }
 808
 809 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 810 {
 811     int i, n;
 812     unsigned int b;
 813     size_t soutl;
 814     int ret;
 815     int blocksize;
 816
 817     /* Prevent accidental use of encryption context when decrypting */
 818     if (ctx->encrypt) {
 819         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 820         return 0;
 821     }
 822
 823     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 824         goto legacy;
 825
 826     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 827
 828     if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
 829         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 830         return 0;
 831     }
 832
 833     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
 834                               blocksize == 1 ? 0 : blocksize);
 835
 836     if (ret) {
 837         if (soutl > INT_MAX) {
 838             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 839             return 0;
 840         }
 841         *outl = soutl;
 842     }
 843
 844     return ret;
 845
 846     /* TODO(3.0): Remove legacy code below */
 847  legacy:
 848
 849     *outl = 0;
 850     if (ctx->cipher == NULL) {
 851         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_NO_CIPHER_SET);
 852         return 0;
 853     }
 854
 855     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 856         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 857         if (i < 0)
 858             return 0;
 859         else
 860             *outl = i;
 861         return 1;
 862     }
 863
 864     b = ctx->cipher->block_size;
 865     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 866         if (ctx->buf_len) {
 867             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 868                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 869             return 0;
 870         }
 871         *outl = 0;
 872         return 1;
 873     }
 874     if (b > 1) {
 875         if (ctx->buf_len || !ctx->final_used) {
 876             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 877             return 0;
 878         }
 879         OPENSSL_assert(b <= sizeof(ctx->final));
 880
 881         /*
 882          * The following assumes that the ciphertext has been authenticated.
 883          * Otherwise it provides a padding oracle.
 884          */
 885         n = ctx->final[b - 1];
 886         if (n == 0 || n > (int)b) {
 887             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 888             return 0;
 889         }
 890         for (i = 0; i < n; i++) {
 891             if (ctx->final[--b] != n) {
 892                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 893                 return 0;
 894             }
 895         }
 896         n = ctx->cipher->block_size - n;
 897         for (i = 0; i < n; i++)
 898             out[i] = ctx->final[i];
 899         *outl = n;
 900     } else
 901         *outl = 0;
 902     return 1;
 903 }
 904
 905 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 906 {
 907     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 908         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 909     if (EVP_CIPHER_CTX_key_length(c) == keylen)
 910         return 1;
 911     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 912         c->key_len = keylen;
 913         return 1;
 914     }
 915     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 916     return 0;
 917 }
 918
 919 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 920 {
 921     if (pad)
 922         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 923     else
 924         ctx->flags |= EVP_CIPH_NO_PADDING;
 925
 926     if (ctx->cipher != NULL && ctx->cipher->prov != NULL) {
 927         OSSL_PARAM params[] = {
 928             OSSL_PARAM_int(OSSL_CIPHER_PARAM_PADDING, NULL),
 929             OSSL_PARAM_END
 930         };
 931
 932         params[0].data = &pad;
 933
 934         if (ctx->cipher->ctx_set_params == NULL) {
 935             EVPerr(EVP_F_EVP_CIPHER_CTX_SET_PADDING, EVP_R_CTRL_NOT_IMPLEMENTED);
 936             return 0;
 937         }
 938
 939         if (!ctx->cipher->ctx_set_params(ctx->provctx, params))
 940             return 0;
 941     }
 942
 943     return 1;
 944 }
 945
 946 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 947 {
 948     int ret;
 949
 950     if (!ctx->cipher) {
 951         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 952         return 0;
 953     }
 954
 955     if (!ctx->cipher->ctrl) {
 956         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 957         return 0;
 958     }
 959
 960     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 961     if (ret == -1) {
 962         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 963                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 964         return 0;
 965     }
 966     return ret;
 967 }
 968
 969 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 970 {
 971     int kl;
 972     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 973         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 974     kl = EVP_CIPHER_CTX_key_length(ctx);
 975     if (kl <= 0 || RAND_priv_bytes(key, kl) <= 0)
 976         return 0;
 977     return 1;
 978 }
 979
 980 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 981 {
 982     if ((in == NULL) || (in->cipher == NULL)) {
 983         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 984         return 0;
 985     }
 986
 987     if (in->cipher->prov == NULL)
 988         goto legacy;
 989
 990     if (in->cipher->dupctx == NULL) {
 991         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 992         return 0;
 993     }
 994
 995     EVP_CIPHER_CTX_reset(out);
 996
 997     *out = *in;
 998     out->provctx = NULL;
 999
1000     if (in->fetched_cipher != NULL && !EVP_CIPHER_upref(in->fetched_cipher)) {
1001         out->fetched_cipher = NULL;
1002         return 0;
1003     }
1004
1005     out->provctx = in->cipher->dupctx(in->provctx);
1006     if (out->provctx == NULL) {
1007         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
1008         return 0;
1009     }
1010
1011     return 1;
1012
1013     /* TODO(3.0): Remove legacy code below */
1014  legacy:
1015
1016 #ifndef OPENSSL_NO_ENGINE
1017     /* Make sure it's safe to copy a cipher context using an ENGINE */
1018     if (in->engine && !ENGINE_init(in->engine)) {
1019         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
1020         return 0;
1021     }
1022 #endif
1023
1024     EVP_CIPHER_CTX_reset(out);
1025     memcpy(out, in, sizeof(*out));
1026
1027     if (in->cipher_data && in->cipher->ctx_size) {
1028         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
1029         if (out->cipher_data == NULL) {
1030             out->cipher = NULL;
1031             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
1032             return 0;
1033         }
1034         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
1035     }
1036
1037     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
1038         if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
1039             out->cipher = NULL;
1040             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
1041             return 0;
1042         }
1043     return 1;
1044 }
1045
1046 static void *evp_cipher_from_dispatch(const OSSL_DISPATCH *fns,
1047                                       OSSL_PROVIDER *prov)
1048 {
1049     EVP_CIPHER *cipher = NULL;
1050     int fnciphcnt = 0, fnctxcnt = 0;
1051
1052     /*
1053      * The legacy NID is set by EVP_CIPHER_fetch() if the name exists in
1054      * the object database.
1055      */
1056     if ((cipher = EVP_CIPHER_meth_new(0, 0, 0)) == NULL)
1057         return NULL;
1058
1059     for (; fns->function_id != 0; fns++) {
1060         switch (fns->function_id) {
1061         case OSSL_FUNC_CIPHER_NEWCTX:
1062             if (cipher->newctx != NULL)
1063                 break;
1064             cipher->newctx = OSSL_get_OP_cipher_newctx(fns);
1065             fnctxcnt++;
1066             break;
1067         case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
1068             if (cipher->einit != NULL)
1069                 break;
1070             cipher->einit = OSSL_get_OP_cipher_encrypt_init(fns);
1071             fnciphcnt++;
1072             break;
1073         case OSSL_FUNC_CIPHER_DECRYPT_INIT:
1074             if (cipher->dinit != NULL)
1075                 break;
1076             cipher->dinit = OSSL_get_OP_cipher_decrypt_init(fns);
1077             fnciphcnt++;
1078             break;
1079         case OSSL_FUNC_CIPHER_UPDATE:
1080             if (cipher->cupdate != NULL)
1081                 break;
1082             cipher->cupdate = OSSL_get_OP_cipher_update(fns);
1083             fnciphcnt++;
1084             break;
1085         case OSSL_FUNC_CIPHER_FINAL:
1086             if (cipher->cfinal != NULL)
1087                 break;
1088             cipher->cfinal = OSSL_get_OP_cipher_final(fns);
1089             fnciphcnt++;
1090             break;
1091         case OSSL_FUNC_CIPHER_CIPHER:
1092             if (cipher->ccipher != NULL)
1093                 break;
1094             cipher->ccipher = OSSL_get_OP_cipher_cipher(fns);
1095             break;
1096         case OSSL_FUNC_CIPHER_FREECTX:
1097             if (cipher->freectx != NULL)
1098                 break;
1099             cipher->freectx = OSSL_get_OP_cipher_freectx(fns);
1100             fnctxcnt++;
1101             break;
1102         case OSSL_FUNC_CIPHER_DUPCTX:
1103             if (cipher->dupctx != NULL)
1104                 break;
1105             cipher->dupctx = OSSL_get_OP_cipher_dupctx(fns);
1106             break;
1107         case OSSL_FUNC_CIPHER_KEY_LENGTH:
1108             if (cipher->key_length != NULL)
1109                 break;
1110             cipher->key_length = OSSL_get_OP_cipher_key_length(fns);
1111             break;
1112         case OSSL_FUNC_CIPHER_IV_LENGTH:
1113             if (cipher->iv_length != NULL)
1114                 break;
1115             cipher->iv_length = OSSL_get_OP_cipher_iv_length(fns);
1116             break;
1117         case OSSL_FUNC_CIPHER_BLOCK_SIZE:
1118             if (cipher->blocksize != NULL)
1119                 break;
1120             cipher->blocksize = OSSL_get_OP_cipher_block_size(fns);
1121             break;
1122         case OSSL_FUNC_CIPHER_GET_PARAMS:
1123             if (cipher->get_params != NULL)
1124                 break;
1125             cipher->get_params = OSSL_get_OP_cipher_get_params(fns);
1126             break;
1127         case OSSL_FUNC_CIPHER_CTX_GET_PARAMS:
1128             if (cipher->ctx_get_params != NULL)
1129                 break;
1130             cipher->ctx_get_params = OSSL_get_OP_cipher_ctx_get_params(fns);
1131             break;
1132         case OSSL_FUNC_CIPHER_CTX_SET_PARAMS:
1133             if (cipher->ctx_set_params != NULL)
1134                 break;
1135             cipher->ctx_set_params = OSSL_get_OP_cipher_ctx_set_params(fns);
1136             break;
1137         }
1138     }
1139     if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
1140             || (fnciphcnt == 0 && cipher->ccipher == NULL)
1141             || fnctxcnt != 2
1142             || cipher->blocksize == NULL
1143             || cipher->iv_length == NULL
1144             || cipher->key_length == NULL) {
1145         /*
1146          * In order to be a consistent set of functions we must have at least
1147          * a complete set of "encrypt" functions, or a complete set of "decrypt"
1148          * functions, or a single "cipher" function. In all cases we need a
1149          * complete set of context management functions, as well as the
1150          * blocksize, iv_length and key_length functions.
1151          */
1152         EVP_CIPHER_meth_free(cipher);
1153         EVPerr(EVP_F_EVP_CIPHER_FROM_DISPATCH, EVP_R_INVALID_PROVIDER_FUNCTIONS);
1154         return NULL;
1155     }
1156     cipher->prov = prov;
1157     if (prov != NULL)
1158         ossl_provider_upref(prov);
1159
1160     return cipher;
1161 }
1162
1163 static int evp_cipher_upref(void *cipher)
1164 {
1165     return EVP_CIPHER_upref(cipher);
1166 }
1167
1168 static void evp_cipher_free(void *cipher)
1169 {
1170     EVP_CIPHER_meth_free(cipher);
1171 }
1172
1173 EVP_CIPHER *EVP_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
1174                              const char *properties)
1175 {
1176     EVP_CIPHER *cipher =
1177         evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
1178                           evp_cipher_from_dispatch, evp_cipher_upref,
1179                           evp_cipher_free);
1180
1181 #ifndef FIPS_MODE
1182     /* TODO(3.x) get rid of the need for legacy NIDs */
1183     if (cipher != NULL) {
1184         /*
1185          * FIPS module note: since internal fetches will be entirely
1186          * provider based, we know that none of its code depends on legacy
1187          * NIDs or any functionality that use them.
1188          */
1189         cipher->nid = OBJ_sn2nid(algorithm);
1190     }
1191 #endif
1192
1193     return cipher;
1194 }