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 (inl <= 0) {
 499         *outl = 0;
 500         return inl == 0;
 501     }
 502
 503     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 504         /* If block size > 1 then the cipher will have to do this check */
 505         if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
 506             EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 507             return 0;
 508         }
 509
 510         i = ctx->cipher->do_cipher(ctx, out, in, inl);
 511         if (i < 0)
 512             return 0;
 513         else
 514             *outl = i;
 515         return 1;
 516     }
 517
 518     if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
 519         EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 520         return 0;
 521     }
 522
 523     if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
 524         if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
 525             *outl = inl;
 526             return 1;
 527         } else {
 528             *outl = 0;
 529             return 0;
 530         }
 531     }
 532     i = ctx->buf_len;
 533     OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
 534     if (i != 0) {
 535         if (bl - i > inl) {
 536             memcpy(&(ctx->buf[i]), in, inl);
 537             ctx->buf_len += inl;
 538             *outl = 0;
 539             return 1;
 540         } else {
 541             j = bl - i;
 542             memcpy(&(ctx->buf[i]), in, j);
 543             inl -= j;
 544             in += j;
 545             if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
 546                 return 0;
 547             out += bl;
 548             *outl = bl;
 549         }
 550     } else
 551         *outl = 0;
 552     i = inl & (bl - 1);
 553     inl -= i;
 554     if (inl > 0) {
 555         if (!ctx->cipher->do_cipher(ctx, out, in, inl))
 556             return 0;
 557         *outl += inl;
 558     }
 559
 560     if (i != 0)
 561         memcpy(ctx->buf, &(in[inl]), i);
 562     ctx->buf_len = i;
 563     return 1;
 564 }
 565
 566
 567 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 568                       const unsigned char *in, int inl)
 569 {
 570     int ret;
 571     size_t soutl;
 572     int blocksize;
 573
 574     /* Prevent accidental use of decryption context when encrypting */
 575     if (!ctx->encrypt) {
 576         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
 577         return 0;
 578     }
 579
 580     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 581         goto legacy;
 582
 583     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 584
 585     if (ctx->cipher->cupdate == NULL  || blocksize < 1) {
 586         EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 587         return 0;
 588     }
 589     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
 590                                inl + (blocksize == 1 ? 0 : blocksize), in,
 591                                (size_t)inl);
 592
 593     if (ret) {
 594         if (soutl > INT_MAX) {
 595             EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
 596             return 0;
 597         }
 598         *outl = soutl;
 599     }
 600
 601     return ret;
 602
 603     /* TODO(3.0): Remove legacy code below */
 604  legacy:
 605
 606     return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 607 }
 608
 609 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 610 {
 611     int ret;
 612     ret = EVP_EncryptFinal_ex(ctx, out, outl);
 613     return ret;
 614 }
 615
 616 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 617 {
 618     int n, ret;
 619     unsigned int i, b, bl;
 620     size_t soutl;
 621     int blocksize;
 622
 623     /* Prevent accidental use of decryption context when encrypting */
 624     if (!ctx->encrypt) {
 625         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 626         return 0;
 627     }
 628
 629     if (ctx->cipher == NULL) {
 630         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_NO_CIPHER_SET);
 631         return 0;
 632     }
 633     if (ctx->cipher->prov == NULL)
 634         goto legacy;
 635
 636     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 637
 638     if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
 639         EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 640         return 0;
 641     }
 642
 643     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
 644                               blocksize == 1 ? 0 : blocksize);
 645
 646     if (ret) {
 647         if (soutl > INT_MAX) {
 648             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 649             return 0;
 650         }
 651         *outl = soutl;
 652     }
 653
 654     return ret;
 655
 656     /* TODO(3.0): Remove legacy code below */
 657  legacy:
 658
 659     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 660         ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 661         if (ret < 0)
 662             return 0;
 663         else
 664             *outl = ret;
 665         return 1;
 666     }
 667
 668     b = ctx->cipher->block_size;
 669     OPENSSL_assert(b <= sizeof(ctx->buf));
 670     if (b == 1) {
 671         *outl = 0;
 672         return 1;
 673     }
 674     bl = ctx->buf_len;
 675     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 676         if (bl) {
 677             EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
 678                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 679             return 0;
 680         }
 681         *outl = 0;
 682         return 1;
 683     }
 684
 685     n = b - bl;
 686     for (i = bl; i < b; i++)
 687         ctx->buf[i] = n;
 688     ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
 689
 690     if (ret)
 691         *outl = b;
 692
 693     return ret;
 694 }
 695
 696 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 697                       const unsigned char *in, int inl)
 698 {
 699     int fix_len, cmpl = inl, ret;
 700     unsigned int b;
 701     size_t soutl;
 702     int blocksize;
 703
 704     /* Prevent accidental use of encryption context when decrypting */
 705     if (ctx->encrypt) {
 706         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
 707         return 0;
 708     }
 709
 710     if (ctx->cipher == NULL) {
 711         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_NO_CIPHER_SET);
 712         return 0;
 713     }
 714     if (ctx->cipher->prov == NULL)
 715         goto legacy;
 716
 717     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 718
 719     if (ctx->cipher->cupdate == NULL || blocksize < 1) {
 720         EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 721         return 0;
 722     }
 723     ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
 724                                inl + (blocksize == 1 ? 0 : blocksize), in,
 725                                (size_t)inl);
 726
 727     if (ret) {
 728         if (soutl > INT_MAX) {
 729             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
 730             return 0;
 731         }
 732         *outl = soutl;
 733     }
 734
 735     return ret;
 736
 737     /* TODO(3.0): Remove legacy code below */
 738  legacy:
 739
 740     b = ctx->cipher->block_size;
 741
 742     if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
 743         cmpl = (cmpl + 7) / 8;
 744
 745     if (inl <= 0) {
 746         *outl = 0;
 747         return inl == 0;
 748     }
 749
 750     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 751         if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
 752             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 753             return 0;
 754         }
 755
 756         fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
 757         if (fix_len < 0) {
 758             *outl = 0;
 759             return 0;
 760         } else
 761             *outl = fix_len;
 762         return 1;
 763     }
 764
 765     if (ctx->flags & EVP_CIPH_NO_PADDING)
 766         return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
 767
 768     OPENSSL_assert(b <= sizeof(ctx->final));
 769
 770     if (ctx->final_used) {
 771         /* see comment about PTRDIFF_T comparison above */
 772         if (((PTRDIFF_T)out == (PTRDIFF_T)in)
 773             || is_partially_overlapping(out, in, b)) {
 774             EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
 775             return 0;
 776         }
 777         memcpy(out, ctx->final, b);
 778         out += b;
 779         fix_len = 1;
 780     } else
 781         fix_len = 0;
 782
 783     if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
 784         return 0;
 785
 786     /*
 787      * if we have 'decrypted' a multiple of block size, make sure we have a
 788      * copy of this last block
 789      */
 790     if (b > 1 && !ctx->buf_len) {
 791         *outl -= b;
 792         ctx->final_used = 1;
 793         memcpy(ctx->final, &out[*outl], b);
 794     } else
 795         ctx->final_used = 0;
 796
 797     if (fix_len)
 798         *outl += b;
 799
 800     return 1;
 801 }
 802
 803 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 804 {
 805     int ret;
 806     ret = EVP_DecryptFinal_ex(ctx, out, outl);
 807     return ret;
 808 }
 809
 810 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 811 {
 812     int i, n;
 813     unsigned int b;
 814     size_t soutl;
 815     int ret;
 816     int blocksize;
 817
 818     /* Prevent accidental use of encryption context when decrypting */
 819     if (ctx->encrypt) {
 820         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
 821         return 0;
 822     }
 823
 824     if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
 825         goto legacy;
 826
 827     blocksize = EVP_CIPHER_CTX_block_size(ctx);
 828
 829     if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
 830         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 831         return 0;
 832     }
 833
 834     ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
 835                               blocksize == 1 ? 0 : blocksize);
 836
 837     if (ret) {
 838         if (soutl > INT_MAX) {
 839             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
 840             return 0;
 841         }
 842         *outl = soutl;
 843     }
 844
 845     return ret;
 846
 847     /* TODO(3.0): Remove legacy code below */
 848  legacy:
 849
 850     *outl = 0;
 851     if (ctx->cipher == NULL) {
 852         EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_NO_CIPHER_SET);
 853         return 0;
 854     }
 855
 856     if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
 857         i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
 858         if (i < 0)
 859             return 0;
 860         else
 861             *outl = i;
 862         return 1;
 863     }
 864
 865     b = ctx->cipher->block_size;
 866     if (ctx->flags & EVP_CIPH_NO_PADDING) {
 867         if (ctx->buf_len) {
 868             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
 869                    EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 870             return 0;
 871         }
 872         *outl = 0;
 873         return 1;
 874     }
 875     if (b > 1) {
 876         if (ctx->buf_len || !ctx->final_used) {
 877             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 878             return 0;
 879         }
 880         OPENSSL_assert(b <= sizeof(ctx->final));
 881
 882         /*
 883          * The following assumes that the ciphertext has been authenticated.
 884          * Otherwise it provides a padding oracle.
 885          */
 886         n = ctx->final[b - 1];
 887         if (n == 0 || n > (int)b) {
 888             EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 889             return 0;
 890         }
 891         for (i = 0; i < n; i++) {
 892             if (ctx->final[--b] != n) {
 893                 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
 894                 return 0;
 895             }
 896         }
 897         n = ctx->cipher->block_size - n;
 898         for (i = 0; i < n; i++)
 899             out[i] = ctx->final[i];
 900         *outl = n;
 901     } else
 902         *outl = 0;
 903     return 1;
 904 }
 905
 906 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 907 {
 908     if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 909         return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 910     if (EVP_CIPHER_CTX_key_length(c) == keylen)
 911         return 1;
 912     if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
 913         c->key_len = keylen;
 914         return 1;
 915     }
 916     EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
 917     return 0;
 918 }
 919
 920 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 921 {
 922     if (pad)
 923         ctx->flags &= ~EVP_CIPH_NO_PADDING;
 924     else
 925         ctx->flags |= EVP_CIPH_NO_PADDING;
 926
 927     if (ctx->cipher != NULL && ctx->cipher->prov != NULL) {
 928         OSSL_PARAM params[] = {
 929             OSSL_PARAM_int(OSSL_CIPHER_PARAM_PADDING, NULL),
 930             OSSL_PARAM_END
 931         };
 932
 933         params[0].data = &pad;
 934
 935         if (ctx->cipher->ctx_set_params == NULL) {
 936             EVPerr(EVP_F_EVP_CIPHER_CTX_SET_PADDING, EVP_R_CTRL_NOT_IMPLEMENTED);
 937             return 0;
 938         }
 939
 940         if (!ctx->cipher->ctx_set_params(ctx->provctx, params))
 941             return 0;
 942     }
 943
 944     return 1;
 945 }
 946
 947 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 948 {
 949     int ret;
 950
 951     if (!ctx->cipher) {
 952         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 953         return 0;
 954     }
 955
 956     if (!ctx->cipher->ctrl) {
 957         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 958         return 0;
 959     }
 960
 961     ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 962     if (ret == -1) {
 963         EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
 964                EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 965         return 0;
 966     }
 967     return ret;
 968 }
 969
 970 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
 971 {
 972     int kl;
 973     if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
 974         return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
 975     kl = EVP_CIPHER_CTX_key_length(ctx);
 976     if (kl <= 0 || RAND_priv_bytes(key, kl) <= 0)
 977         return 0;
 978     return 1;
 979 }
 980
 981 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
 982 {
 983     if ((in == NULL) || (in->cipher == NULL)) {
 984         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
 985         return 0;
 986     }
 987
 988     if (in->cipher->prov == NULL)
 989         goto legacy;
 990
 991     if (in->cipher->dupctx == NULL) {
 992         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
 993         return 0;
 994     }
 995
 996     EVP_CIPHER_CTX_reset(out);
 997
 998     *out = *in;
 999     out->provctx = NULL;
1000
1001     if (in->fetched_cipher != NULL && !EVP_CIPHER_upref(in->fetched_cipher)) {
1002         out->fetched_cipher = NULL;
1003         return 0;
1004     }
1005
1006     out->provctx = in->cipher->dupctx(in->provctx);
1007     if (out->provctx == NULL) {
1008         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
1009         return 0;
1010     }
1011
1012     return 1;
1013
1014     /* TODO(3.0): Remove legacy code below */
1015  legacy:
1016
1017 #ifndef OPENSSL_NO_ENGINE
1018     /* Make sure it's safe to copy a cipher context using an ENGINE */
1019     if (in->engine && !ENGINE_init(in->engine)) {
1020         EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
1021         return 0;
1022     }
1023 #endif
1024
1025     EVP_CIPHER_CTX_reset(out);
1026     memcpy(out, in, sizeof(*out));
1027
1028     if (in->cipher_data && in->cipher->ctx_size) {
1029         out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
1030         if (out->cipher_data == NULL) {
1031             out->cipher = NULL;
1032             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
1033             return 0;
1034         }
1035         memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
1036     }
1037
1038     if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
1039         if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
1040             out->cipher = NULL;
1041             EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
1042             return 0;
1043         }
1044     return 1;
1045 }
1046
1047 static void *evp_cipher_from_dispatch(int nid, const OSSL_DISPATCH *fns,
1048                                       OSSL_PROVIDER *prov)
1049 {
1050     EVP_CIPHER *cipher = NULL;
1051     int fnciphcnt = 0, fnctxcnt = 0;
1052
1053     if ((cipher = EVP_CIPHER_meth_new(nid, 0, 0)) == NULL)
1054         return NULL;
1055
1056     for (; fns->function_id != 0; fns++) {
1057         switch (fns->function_id) {
1058         case OSSL_FUNC_CIPHER_NEWCTX:
1059             if (cipher->newctx != NULL)
1060                 break;
1061             cipher->newctx = OSSL_get_OP_cipher_newctx(fns);
1062             fnctxcnt++;
1063             break;
1064         case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
1065             if (cipher->einit != NULL)
1066                 break;
1067             cipher->einit = OSSL_get_OP_cipher_encrypt_init(fns);
1068             fnciphcnt++;
1069             break;
1070         case OSSL_FUNC_CIPHER_DECRYPT_INIT:
1071             if (cipher->dinit != NULL)
1072                 break;
1073             cipher->dinit = OSSL_get_OP_cipher_decrypt_init(fns);
1074             fnciphcnt++;
1075             break;
1076         case OSSL_FUNC_CIPHER_UPDATE:
1077             if (cipher->cupdate != NULL)
1078                 break;
1079             cipher->cupdate = OSSL_get_OP_cipher_update(fns);
1080             fnciphcnt++;
1081             break;
1082         case OSSL_FUNC_CIPHER_FINAL:
1083             if (cipher->cfinal != NULL)
1084                 break;
1085             cipher->cfinal = OSSL_get_OP_cipher_final(fns);
1086             fnciphcnt++;
1087             break;
1088         case OSSL_FUNC_CIPHER_CIPHER:
1089             if (cipher->ccipher != NULL)
1090                 break;
1091             cipher->ccipher = OSSL_get_OP_cipher_cipher(fns);
1092             break;
1093         case OSSL_FUNC_CIPHER_FREECTX:
1094             if (cipher->freectx != NULL)
1095                 break;
1096             cipher->freectx = OSSL_get_OP_cipher_freectx(fns);
1097             fnctxcnt++;
1098             break;
1099         case OSSL_FUNC_CIPHER_DUPCTX:
1100             if (cipher->dupctx != NULL)
1101                 break;
1102             cipher->dupctx = OSSL_get_OP_cipher_dupctx(fns);
1103             break;
1104         case OSSL_FUNC_CIPHER_KEY_LENGTH:
1105             if (cipher->key_length != NULL)
1106                 break;
1107             cipher->key_length = OSSL_get_OP_cipher_key_length(fns);
1108             break;
1109         case OSSL_FUNC_CIPHER_IV_LENGTH:
1110             if (cipher->iv_length != NULL)
1111                 break;
1112             cipher->iv_length = OSSL_get_OP_cipher_iv_length(fns);
1113             break;
1114         case OSSL_FUNC_CIPHER_BLOCK_SIZE:
1115             if (cipher->blocksize != NULL)
1116                 break;
1117             cipher->blocksize = OSSL_get_OP_cipher_block_size(fns);
1118             break;
1119         case OSSL_FUNC_CIPHER_GET_PARAMS:
1120             if (cipher->get_params != NULL)
1121                 break;
1122             cipher->get_params = OSSL_get_OP_cipher_get_params(fns);
1123             break;
1124         case OSSL_FUNC_CIPHER_CTX_GET_PARAMS:
1125             if (cipher->ctx_get_params != NULL)
1126                 break;
1127             cipher->ctx_get_params = OSSL_get_OP_cipher_ctx_get_params(fns);
1128             break;
1129         case OSSL_FUNC_CIPHER_CTX_SET_PARAMS:
1130             if (cipher->ctx_set_params != NULL)
1131                 break;
1132             cipher->ctx_set_params = OSSL_get_OP_cipher_ctx_set_params(fns);
1133             break;
1134         }
1135     }
1136     if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
1137             || (fnciphcnt == 0 && cipher->ccipher == NULL)
1138             || fnctxcnt != 2
1139             || cipher->blocksize == NULL
1140             || cipher->iv_length == NULL
1141             || cipher->key_length == NULL) {
1142         /*
1143          * In order to be a consistent set of functions we must have at least
1144          * a complete set of "encrypt" functions, or a complete set of "decrypt"
1145          * functions, or a single "cipher" function. In all cases we need a
1146          * complete set of context management functions, as well as the
1147          * blocksize, iv_length and key_length functions.
1148          */
1149         EVP_CIPHER_meth_free(cipher);
1150         EVPerr(EVP_F_EVP_CIPHER_FROM_DISPATCH, EVP_R_INVALID_PROVIDER_FUNCTIONS);
1151         return NULL;
1152     }
1153     cipher->prov = prov;
1154     if (prov != NULL)
1155         ossl_provider_upref(prov);
1156
1157     return cipher;
1158 }
1159
1160 static int evp_cipher_upref(void *cipher)
1161 {
1162     return EVP_CIPHER_upref(cipher);
1163 }
1164
1165 static void evp_cipher_free(void *cipher)
1166 {
1167     EVP_CIPHER_meth_free(cipher);
1168 }
1169
1170 static int evp_cipher_nid(void *vcipher)
1171 {
1172     EVP_CIPHER *cipher = vcipher;
1173
1174     return cipher->nid;
1175 }
1176
1177 EVP_CIPHER *EVP_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
1178                              const char *properties)
1179 {
1180     return evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
1181                              evp_cipher_from_dispatch, evp_cipher_upref,
1182                              evp_cipher_free, evp_cipher_nid);
1183 }