text: /*
   * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  /* We need to use some engine deprecated APIs */
  #define OPENSSL_SUPPRESS_DEPRECATED
  
  #include <stdio.h>
  #include <assert.h>
  #include "internal/cryptlib.h"
  #include <openssl/evp.h>
  #include <openssl/err.h>
  #include <openssl/rand.h>
  #include <openssl/engine.h>
  #include <openssl/params.h>
  #include <openssl/core_names.h>
  #include "crypto/evp.h"
  #include "internal/provider.h"
  #include "evp_local.h"
  
  int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx)
  {
      if (ctx == NULL)
          return 1;
  
      if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
          goto legacy;
  
      if (ctx->provctx != NULL) {
          if (ctx->cipher->freectx != NULL)
              ctx->cipher->freectx(ctx->provctx);
          ctx->provctx = NULL;
      }
      if (ctx->fetched_cipher != NULL)
          EVP_CIPHER_free(ctx->fetched_cipher);
      memset(ctx, 0, sizeof(*ctx));
  
      return 1;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      if (ctx->cipher != NULL) {
          if (ctx->cipher->cleanup && !ctx->cipher->cleanup(ctx))
              return 0;
          /* Cleanse cipher context data */
          if (ctx->cipher_data && ctx->cipher->ctx_size)
              OPENSSL_cleanse(ctx->cipher_data, ctx->cipher->ctx_size);
      }
      OPENSSL_free(ctx->cipher_data);
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
      ENGINE_finish(ctx->engine);
  #endif
      memset(ctx, 0, sizeof(*ctx));
      return 1;
  }
  
  EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
  {
      return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX));
  }
  
  void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
  {
      EVP_CIPHER_CTX_reset(ctx);
      OPENSSL_free(ctx);
  }
  
  int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                     const unsigned char *key, const unsigned char *iv, int enc)
  {
      if (cipher != NULL)
          EVP_CIPHER_CTX_reset(ctx);
      return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
  }
  
  int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                        ENGINE *impl, const unsigned char *key,
                        const unsigned char *iv, int enc)
  {
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
      ENGINE *tmpimpl = NULL;
  #endif
      /*
       * enc == 1 means we are encrypting.
       * enc == 0 means we are decrypting.
       * enc == -1 means, use the previously initialised value for encrypt/decrypt
       */
      if (enc == -1) {
          enc = ctx->encrypt;
      } else {
          if (enc)
              enc = 1;
          ctx->encrypt = enc;
      }
  
      if (cipher == NULL && ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
  
      /* TODO(3.0): Legacy work around code below. Remove this */
  
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
      /*
       * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
       * this context may already have an ENGINE! Try to avoid releasing the
       * previous handle, re-querying for an ENGINE, and having a
       * reinitialisation, when it may all be unnecessary.
       */
      if (ctx->engine && ctx->cipher
          && (cipher == NULL || cipher->nid == ctx->cipher->nid))
          goto skip_to_init;
  
      if (cipher != NULL && impl == NULL) {
           /* Ask if an ENGINE is reserved for this job */
          tmpimpl = ENGINE_get_cipher_engine(cipher->nid);
      }
  #endif
  
      /*
       * If there are engines involved then we should use legacy handling for now.
       */
      if (ctx->engine != NULL
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
              || tmpimpl != NULL
  #endif
              || impl != NULL) {
          if (ctx->cipher == ctx->fetched_cipher)
              ctx->cipher = NULL;
          EVP_CIPHER_free(ctx->fetched_cipher);
          ctx->fetched_cipher = NULL;
          goto legacy;
      }
      /*
       * Ensure a context left lying around from last time is cleared
       * (legacy code)
       */
      if (cipher != NULL && ctx->cipher != NULL) {
          OPENSSL_clear_free(ctx->cipher_data, ctx->cipher->ctx_size);
          ctx->cipher_data = NULL;
      }
  
  
      /* TODO(3.0): Start of non-legacy code below */
  
      /* Ensure a context left lying around from last time is cleared */
      if (cipher != NULL && ctx->cipher != NULL) {
          unsigned long flags = ctx->flags;
  
          EVP_CIPHER_CTX_reset(ctx);
          /* Restore encrypt and flags */
          ctx->encrypt = enc;
          ctx->flags = flags;
      }
  
      if (cipher == NULL)
          cipher = ctx->cipher;
  
      if (cipher->prov == NULL) {
  #ifdef FIPS_MODULE
          /* We only do explicit fetches inside the FIPS module */
          ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
          return 0;
  #else
          EVP_CIPHER *provciph =
              EVP_CIPHER_fetch(NULL,
                               cipher->nid == NID_undef ? "NULL"
                                                        : OBJ_nid2sn(cipher->nid),
                               "");
  
          if (provciph == NULL)
              return 0;
          cipher = provciph;
          EVP_CIPHER_free(ctx->fetched_cipher);
          ctx->fetched_cipher = provciph;
  #endif
      }
  
      ctx->cipher = cipher;
      if (ctx->provctx == NULL) {
          ctx->provctx = ctx->cipher->newctx(ossl_provider_ctx(cipher->prov));
          if (ctx->provctx == NULL) {
              ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
              return 0;
          }
      }
  
      if ((ctx->flags & EVP_CIPH_NO_PADDING) != 0) {
          /*
           * If this ctx was already set up for no padding then we need to tell
           * the new cipher about it.
           */
          if (!EVP_CIPHER_CTX_set_padding(ctx, 0))
              return 0;
      }
  
      if (enc) {
          if (ctx->cipher->einit == NULL) {
              ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
              return 0;
          }
  
          return ctx->cipher->einit(ctx->provctx,
                                    key,
                                    key == NULL ? 0
                                                : EVP_CIPHER_CTX_key_length(ctx),
                                    iv,
                                    iv == NULL ? 0
                                               : EVP_CIPHER_CTX_iv_length(ctx));
      }
  
      if (ctx->cipher->dinit == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
          return 0;
      }
  
      return ctx->cipher->dinit(ctx->provctx,
                                key,
                                key == NULL ? 0
                                            : EVP_CIPHER_CTX_key_length(ctx),
                                iv,
                                iv == NULL ? 0
                                           : EVP_CIPHER_CTX_iv_length(ctx));
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      if (cipher != NULL) {
          /*
           * Ensure a context left lying around from last time is cleared (we
           * previously attempted to avoid this if the same ENGINE and
           * EVP_CIPHER could be used).
           */
          if (ctx->cipher) {
              unsigned long flags = ctx->flags;
              EVP_CIPHER_CTX_reset(ctx);
              /* Restore encrypt and flags */
              ctx->encrypt = enc;
              ctx->flags = flags;
          }
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
          if (impl != NULL) {
              if (!ENGINE_init(impl)) {
                  ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
                  return 0;
              }
          } else {
              impl = tmpimpl;
          }
          if (impl != NULL) {
              /* There's an ENGINE for this job ... (apparently) */
              const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
  
              if (c == NULL) {
                  /*
                   * One positive side-effect of US's export control history,
                   * is that we should at least be able to avoid using US
                   * misspellings of "initialisation"?
                   */
                  ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
                  return 0;
              }
              /* We'll use the ENGINE's private cipher definition */
              cipher = c;
              /*
               * Store the ENGINE functional reference so we know 'cipher' came
               * from an ENGINE and we need to release it when done.
               */
              ctx->engine = impl;
          } else {
              ctx->engine = NULL;
          }
  #endif
  
          ctx->cipher = cipher;
          if (ctx->cipher->ctx_size) {
              ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
              if (ctx->cipher_data == NULL) {
                  ctx->cipher = NULL;
                  ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
                  return 0;
              }
          } else {
              ctx->cipher_data = NULL;
          }
          ctx->key_len = cipher->key_len;
          /* Preserve wrap enable flag, zero everything else */
          ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
          if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
              if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
                  ctx->cipher = NULL;
                  ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
                  return 0;
              }
          }
      }
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
   skip_to_init:
  #endif
      if (ctx->cipher == NULL)
          return 0;
  
      /* we assume block size is a power of 2 in *cryptUpdate */
      OPENSSL_assert(ctx->cipher->block_size == 1
                     || ctx->cipher->block_size == 8
                     || ctx->cipher->block_size == 16);
  
      if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
          && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
          ERR_raise(ERR_LIB_EVP, EVP_R_WRAP_MODE_NOT_ALLOWED);
          return 0;
      }
  
      if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
          switch (EVP_CIPHER_CTX_mode(ctx)) {
  
          case EVP_CIPH_STREAM_CIPHER:
          case EVP_CIPH_ECB_MODE:
              break;
  
          case EVP_CIPH_CFB_MODE:
          case EVP_CIPH_OFB_MODE:
  
              ctx->num = 0;
              /* fall-through */
  
          case EVP_CIPH_CBC_MODE:
  
              OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
                             (int)sizeof(ctx->iv));
              if (iv)
                  memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
              memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
              break;
  
          case EVP_CIPH_CTR_MODE:
              ctx->num = 0;
              /* Don't reuse IV for CTR mode */
              if (iv)
                  memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
              break;
  
          default:
              return 0;
          }
      }
  
      if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
          if (!ctx->cipher->init(ctx, key, iv, enc))
              return 0;
      }
      ctx->buf_len = 0;
      ctx->final_used = 0;
      ctx->block_mask = ctx->cipher->block_size - 1;
      return 1;
  }
  
  int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                       const unsigned char *in, int inl)
  {
      if (ctx->encrypt)
          return EVP_EncryptUpdate(ctx, out, outl, in, inl);
      else
          return EVP_DecryptUpdate(ctx, out, outl, in, inl);
  }
  
  int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      if (ctx->encrypt)
          return EVP_EncryptFinal_ex(ctx, out, outl);
      else
          return EVP_DecryptFinal_ex(ctx, out, outl);
  }
  
  int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      if (ctx->encrypt)
          return EVP_EncryptFinal(ctx, out, outl);
      else
          return EVP_DecryptFinal(ctx, out, outl);
  }
  
  int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                      const unsigned char *key, const unsigned char *iv)
  {
      return EVP_CipherInit(ctx, cipher, key, iv, 1);
  }
  
  int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                         ENGINE *impl, const unsigned char *key,
                         const unsigned char *iv)
  {
      return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
  }
  
  int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                      const unsigned char *key, const unsigned char *iv)
  {
      return EVP_CipherInit(ctx, cipher, key, iv, 0);
  }
  
  int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                         ENGINE *impl, const unsigned char *key,
                         const unsigned char *iv)
  {
      return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
  }
  
  /*
   * According to the letter of standard difference between pointers
   * is specified to be valid only within same object. This makes
   * it formally challenging to determine if input and output buffers
   * are not partially overlapping with standard pointer arithmetic.
   */
  #ifdef PTRDIFF_T
  # undef PTRDIFF_T
  #endif
  #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
  /*
   * Then we have VMS that distinguishes itself by adhering to
   * sizeof(size_t)==4 even in 64-bit builds, which means that
   * difference between two pointers might be truncated to 32 bits.
   * In the context one can even wonder how comparison for
   * equality is implemented. To be on the safe side we adhere to
   * PTRDIFF_T even for comparison for equality.
   */
  # define PTRDIFF_T uint64_t
  #else
  # define PTRDIFF_T size_t
  #endif
  
  int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
  {
      PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
      /*
       * Check for partially overlapping buffers. [Binary logical
       * operations are used instead of boolean to minimize number
       * of conditional branches.]
       */
      int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
                                                  (diff > (0 - (PTRDIFF_T)len)));
  
      return overlapped;
  }
  
  static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
                                      unsigned char *out, int *outl,
                                      const unsigned char *in, int inl)
  {
      int i, j, bl, cmpl = inl;
  
      if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
          cmpl = (cmpl + 7) / 8;
  
      bl = ctx->cipher->block_size;
  
      if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
          /* If block size > 1 then the cipher will have to do this check */
          if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
              ERR_raise(ERR_LIB_EVP, EVP_R_PARTIALLY_OVERLAPPING);
              return 0;
          }
  
          i = ctx->cipher->do_cipher(ctx, out, in, inl);
          if (i < 0)
              return 0;
          else
              *outl = i;
          return 1;
      }
  
      if (inl <= 0) {
          *outl = 0;
          return inl == 0;
      }
      if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
          ERR_raise(ERR_LIB_EVP, EVP_R_PARTIALLY_OVERLAPPING);
          return 0;
      }
  
      if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
          if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
              *outl = inl;
              return 1;
          } else {
              *outl = 0;
              return 0;
          }
      }
      i = ctx->buf_len;
      OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
      if (i != 0) {
          if (bl - i > inl) {
              memcpy(&(ctx->buf[i]), in, inl);
              ctx->buf_len += inl;
              *outl = 0;
              return 1;
          } else {
              j = bl - i;
              memcpy(&(ctx->buf[i]), in, j);
              inl -= j;
              in += j;
              if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
                  return 0;
              out += bl;
              *outl = bl;
          }
      } else
          *outl = 0;
      i = inl & (bl - 1);
      inl -= i;
      if (inl > 0) {
          if (!ctx->cipher->do_cipher(ctx, out, in, inl))
              return 0;
          *outl += inl;
      }
  
      if (i != 0)
          memcpy(ctx->buf, &(in[inl]), i);
      ctx->buf_len = i;
      return 1;
  }
  
  
  int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                        const unsigned char *in, int inl)
  {
      int ret;
      size_t soutl;
      int blocksize;
  
      if (outl != NULL) {
          *outl = 0;
      } else {
          ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      /* Prevent accidental use of decryption context when encrypting */
      if (!ctx->encrypt) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_OPERATION);
          return 0;
      }
  
      if (ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
  
      if (ctx->cipher->prov == NULL)
          goto legacy;
  
      blocksize = EVP_CIPHER_CTX_block_size(ctx);
  
      if (ctx->cipher->cupdate == NULL  || blocksize < 1) {
          ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);
          return 0;
      }
      ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
                                 inl + (blocksize == 1 ? 0 : blocksize), in,
                                 (size_t)inl);
  
      if (ret) {
          if (soutl > INT_MAX) {
              ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);
              return 0;
          }
          *outl = soutl;
      }
  
      return ret;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
  }
  
  int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      int ret;
      ret = EVP_EncryptFinal_ex(ctx, out, outl);
      return ret;
  }
  
  int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      int n, ret;
      unsigned int i, b, bl;
      size_t soutl;
      int blocksize;
  
      if (outl != NULL) {
          *outl = 0;
      } else {
          ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      /* Prevent accidental use of decryption context when encrypting */
      if (!ctx->encrypt) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_OPERATION);
          return 0;
      }
  
      if (ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
      if (ctx->cipher->prov == NULL)
          goto legacy;
  
      blocksize = EVP_CIPHER_CTX_block_size(ctx);
  
      if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);
          return 0;
      }
  
      ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
                                blocksize == 1 ? 0 : blocksize);
  
      if (ret) {
          if (soutl > INT_MAX) {
              ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);
              return 0;
          }
          *outl = soutl;
      }
  
      return ret;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
          ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
          if (ret < 0)
              return 0;
          else
              *outl = ret;
          return 1;
      }
  
      b = ctx->cipher->block_size;
      OPENSSL_assert(b <= sizeof(ctx->buf));
      if (b == 1) {
          *outl = 0;
          return 1;
      }
      bl = ctx->buf_len;
      if (ctx->flags & EVP_CIPH_NO_PADDING) {
          if (bl) {
              ERR_raise(ERR_LIB_EVP, EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
              return 0;
          }
          *outl = 0;
          return 1;
      }
  
      n = b - bl;
      for (i = bl; i < b; i++)
          ctx->buf[i] = n;
      ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
  
      if (ret)
          *outl = b;
  
      return ret;
  }
  
  int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                        const unsigned char *in, int inl)
  {
      int fix_len, cmpl = inl, ret;
      unsigned int b;
      size_t soutl;
      int blocksize;
  
      if (outl != NULL) {
          *outl = 0;
      } else {
          ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      /* Prevent accidental use of encryption context when decrypting */
      if (ctx->encrypt) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_OPERATION);
          return 0;
      }
  
      if (ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
      if (ctx->cipher->prov == NULL)
          goto legacy;
  
      blocksize = EVP_CIPHER_CTX_block_size(ctx);
  
      if (ctx->cipher->cupdate == NULL || blocksize < 1) {
          ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);
          return 0;
      }
      ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
                                 inl + (blocksize == 1 ? 0 : blocksize), in,
                                 (size_t)inl);
  
      if (ret) {
          if (soutl > INT_MAX) {
              ERR_raise(ERR_LIB_EVP, EVP_R_UPDATE_ERROR);
              return 0;
          }
          *outl = soutl;
      }
  
      return ret;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      b = ctx->cipher->block_size;
  
      if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
          cmpl = (cmpl + 7) / 8;
  
      if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
          if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
              ERR_raise(ERR_LIB_EVP, EVP_R_PARTIALLY_OVERLAPPING);
              return 0;
          }
  
          fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
          if (fix_len < 0) {
              *outl = 0;
              return 0;
          } else
              *outl = fix_len;
          return 1;
      }
  
      if (inl <= 0) {
          *outl = 0;
          return inl == 0;
      }
  
      if (ctx->flags & EVP_CIPH_NO_PADDING)
          return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
  
      OPENSSL_assert(b <= sizeof(ctx->final));
  
      if (ctx->final_used) {
          /* see comment about PTRDIFF_T comparison above */
          if (((PTRDIFF_T)out == (PTRDIFF_T)in)
              || is_partially_overlapping(out, in, b)) {
              ERR_raise(ERR_LIB_EVP, EVP_R_PARTIALLY_OVERLAPPING);
              return 0;
          }
          memcpy(out, ctx->final, b);
          out += b;
          fix_len = 1;
      } else
          fix_len = 0;
  
      if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
          return 0;
  
      /*
       * if we have 'decrypted' a multiple of block size, make sure we have a
       * copy of this last block
       */
      if (b > 1 && !ctx->buf_len) {
          *outl -= b;
          ctx->final_used = 1;
          memcpy(ctx->final, &out[*outl], b);
      } else
          ctx->final_used = 0;
  
      if (fix_len)
          *outl += b;
  
      return 1;
  }
  
  int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      int ret;
      ret = EVP_DecryptFinal_ex(ctx, out, outl);
      return ret;
  }
  
  int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
  {
      int i, n;
      unsigned int b;
      size_t soutl;
      int ret;
      int blocksize;
  
      if (outl != NULL) {
          *outl = 0;
      } else {
          ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      /* Prevent accidental use of encryption context when decrypting */
      if (ctx->encrypt) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_OPERATION);
          return 0;
      }
  
      if (ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
  
      if (ctx->cipher->prov == NULL)
          goto legacy;
  
      blocksize = EVP_CIPHER_CTX_block_size(ctx);
  
      if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);
          return 0;
      }
  
      ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
                                blocksize == 1 ? 0 : blocksize);
  
      if (ret) {
          if (soutl > INT_MAX) {
              ERR_raise(ERR_LIB_EVP, EVP_R_FINAL_ERROR);
              return 0;
          }
          *outl = soutl;
      }
  
      return ret;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
      *outl = 0;
      if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
          i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
          if (i < 0)
              return 0;
          else
              *outl = i;
          return 1;
      }
  
      b = ctx->cipher->block_size;
      if (ctx->flags & EVP_CIPH_NO_PADDING) {
          if (ctx->buf_len) {
              ERR_raise(ERR_LIB_EVP, EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
              return 0;
          }
          *outl = 0;
          return 1;
      }
      if (b > 1) {
          if (ctx->buf_len || !ctx->final_used) {
              ERR_raise(ERR_LIB_EVP, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
              return 0;
          }
          OPENSSL_assert(b <= sizeof(ctx->final));
  
          /*
           * The following assumes that the ciphertext has been authenticated.
           * Otherwise it provides a padding oracle.
           */
          n = ctx->final[b - 1];
          if (n == 0 || n > (int)b) {
              ERR_raise(ERR_LIB_EVP, EVP_R_BAD_DECRYPT);
              return 0;
          }
          for (i = 0; i < n; i++) {
              if (ctx->final[--b] != n) {
                  ERR_raise(ERR_LIB_EVP, EVP_R_BAD_DECRYPT);
                  return 0;
              }
          }
          n = ctx->cipher->block_size - n;
          for (i = 0; i < n; i++)
              out[i] = ctx->final[i];
          *outl = n;
      } else
          *outl = 0;
      return 1;
  }
  
  int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
  {
      if (c->cipher->prov != NULL) {
          int ok;
          OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
          size_t len = keylen;
  
          if (EVP_CIPHER_CTX_key_length(c) == keylen)
              return 1;
  
          /* Check the cipher actually understands this parameter */
          if (OSSL_PARAM_locate_const(EVP_CIPHER_settable_ctx_params(c->cipher),
                                      OSSL_CIPHER_PARAM_KEYLEN) == NULL)
              return 0;
  
          params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_KEYLEN, &len);
          ok = evp_do_ciph_ctx_setparams(c->cipher, c->provctx, params);
  
          return ok > 0 ? 1 : 0;
      }
  
      /* TODO(3.0) legacy code follows */
  
      /*
       * Note there have never been any built-in ciphers that define this flag
       * since it was first introduced.
       */
      if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
          return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
      if (EVP_CIPHER_CTX_key_length(c) == keylen)
          return 1;
      if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
          c->key_len = keylen;
          return 1;
      }
      ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_KEY_LENGTH);
      return 0;
  }
  
  int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
  {
      int ok;
      OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
      unsigned int pd = pad;
  
      if (pad)
          ctx->flags &= ~EVP_CIPH_NO_PADDING;
      else
          ctx->flags |= EVP_CIPH_NO_PADDING;
  
      if (ctx->cipher != NULL && ctx->cipher->prov == NULL)
          return 1;
      params[0] = OSSL_PARAM_construct_uint(OSSL_CIPHER_PARAM_PADDING, &pd);
      ok = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
  
      return ok != 0;
  }
  
  int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
  {
      int ret = EVP_CTRL_RET_UNSUPPORTED;
      int set_params = 1;
      size_t sz = arg;
      unsigned int i;
      OSSL_PARAM params[4] = {
          OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END
      };
  
      if (ctx == NULL || ctx->cipher == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NO_CIPHER_SET);
          return 0;
      }
  
      if (ctx->cipher->prov == NULL)
          goto legacy;
  
      switch (type) {
      case EVP_CTRL_SET_KEY_LENGTH:
          params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_KEYLEN, &sz);
          break;
      case EVP_CTRL_RAND_KEY:      /* Used by DES */
          set_params = 0;
          params[0] =
              OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_RANDOM_KEY,
                                                ptr, sz);
          break;
  
      case EVP_CTRL_INIT:
          /*
           * TODO(3.0) EVP_CTRL_INIT is purely legacy, no provider counterpart
           * As a matter of fact, this should be dead code, but some caller
           * might still do a direct control call with this command, so...
           * Legacy methods return 1 except for exceptional circumstances, so
           * we do the same here to not be disruptive.
           */
          return 1;
      case EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS: /* Used by DASYNC */
      default:
          goto end;
      case EVP_CTRL_AEAD_SET_IVLEN:
          if (arg < 0)
              return 0;
          params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_IVLEN, &sz);
          break;
      case EVP_CTRL_AEAD_SET_IV_FIXED:
          params[0] = OSSL_PARAM_construct_octet_string(
                          OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED, ptr, sz);
          break;
      case EVP_CTRL_GCM_IV_GEN:
          set_params = 0;
          if (arg < 0)
              sz = 0; /* special case that uses the iv length */
          params[0] = OSSL_PARAM_construct_octet_string(
                          OSSL_CIPHER_PARAM_AEAD_TLS1_GET_IV_GEN, ptr, sz);
          break;
      case EVP_CTRL_GCM_SET_IV_INV:
          if (arg < 0)
              return 0;
          params[0] = OSSL_PARAM_construct_octet_string(
                          OSSL_CIPHER_PARAM_AEAD_TLS1_SET_IV_INV, ptr, sz);
          break;
      case EVP_CTRL_GET_RC5_ROUNDS:
          set_params = 0; /* Fall thru */
      case EVP_CTRL_SET_RC5_ROUNDS:
          if (arg < 0)
              return 0;
          i = (unsigned int)arg;
          params[0] = OSSL_PARAM_construct_uint(OSSL_CIPHER_PARAM_ROUNDS, &i);
          break;
      case EVP_CTRL_SET_SPEED:
          if (arg < 0)
              return 0;
          i = (unsigned int)arg;
          params[0] = OSSL_PARAM_construct_uint(OSSL_CIPHER_PARAM_SPEED, &i);
          break;
      case EVP_CTRL_AEAD_GET_TAG:
          set_params = 0; /* Fall thru */
      case EVP_CTRL_AEAD_SET_TAG:
          params[0] = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TAG,
                                                        ptr, sz);
          break;
      case EVP_CTRL_AEAD_TLS1_AAD:
          /* This one does a set and a get - since it returns a size */
          params[0] =
              OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TLS1_AAD,
                                                ptr, sz);
          ret = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              goto end;
          params[0] =
              OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD, &sz);
          ret = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              goto end;
          return sz;
  #ifndef OPENSSL_NO_RC2
      case EVP_CTRL_GET_RC2_KEY_BITS:
          set_params = 0; /* Fall thru */
      case EVP_CTRL_SET_RC2_KEY_BITS:
          params[0] = OSSL_PARAM_construct_size_t(OSSL_CIPHER_PARAM_RC2_KEYBITS, &sz);
          break;
  #endif /* OPENSSL_NO_RC2 */
  #if !defined(OPENSSL_NO_MULTIBLOCK)
      case EVP_CTRL_TLS1_1_MULTIBLOCK_MAX_BUFSIZE:
          params[0] = OSSL_PARAM_construct_size_t(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_SEND_FRAGMENT, &sz);
          ret = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return 0;
  
          params[0] = OSSL_PARAM_construct_size_t(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_BUFSIZE, &sz);
          params[1] = OSSL_PARAM_construct_end();
          ret = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return 0;
          return sz;
      case EVP_CTRL_TLS1_1_MULTIBLOCK_AAD: {
          EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM *p =
              (EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM *)ptr;
  
          if (arg < (int)sizeof(EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM))
              return 0;
  
          params[0] = OSSL_PARAM_construct_octet_string(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD, (void*)p->inp, p->len);
          params[1] = OSSL_PARAM_construct_uint(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE, &p->interleave);
          ret = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return ret;
          /* Retrieve the return values changed by the set */
          params[0] = OSSL_PARAM_construct_size_t(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD_PACKLEN, &sz);
          params[1] = OSSL_PARAM_construct_uint(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE, &p->interleave);
          params[2] = OSSL_PARAM_construct_end();
          ret = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return 0;
          return sz;
      }
      case EVP_CTRL_TLS1_1_MULTIBLOCK_ENCRYPT: {
          EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM *p =
              (EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM *)ptr;
  
          params[0] = OSSL_PARAM_construct_octet_string(
                          OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC, p->out, p->len);
  
          params[1] = OSSL_PARAM_construct_octet_string(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_IN, (void*)p->inp,
                  p->len);
          params[2] = OSSL_PARAM_construct_uint(
                  OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE, &p->interleave);
          ret = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return ret;
          params[0] = OSSL_PARAM_construct_size_t(
                          OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_LEN, &sz);
          params[1] = OSSL_PARAM_construct_end();
          ret = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
          if (ret <= 0)
              return 0;
          return sz;
      }
  #endif /* OPENSSL_NO_MULTIBLOCK */
      case EVP_CTRL_AEAD_SET_MAC_KEY:
          if (arg < 0)
              return -1;
          params[0] = OSSL_PARAM_construct_octet_string(
                  OSSL_CIPHER_PARAM_AEAD_MAC_KEY, ptr, sz);
          break;
      }
  
      if (set_params)
          ret = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);
      else
          ret = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
      goto end;
  
  /* TODO(3.0): Remove legacy code below */
  legacy:
      if (ctx->cipher->ctrl == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_CTRL_NOT_IMPLEMENTED);
          return 0;
      }
  
      ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
  
   end:
      if (ret == EVP_CTRL_RET_UNSUPPORTED) {
          ERR_raise(ERR_LIB_EVP, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
          return 0;
      }
      return ret;
  }
  
  int EVP_CIPHER_get_params(EVP_CIPHER *cipher, OSSL_PARAM params[])
  {
      if (cipher != NULL && cipher->get_params != NULL)
          return cipher->get_params(params);
      return 0;
  }
  
  int EVP_CIPHER_CTX_set_params(EVP_CIPHER_CTX *ctx, const OSSL_PARAM params[])
  {
      if (ctx->cipher != NULL && ctx->cipher->set_ctx_params != NULL)
          return ctx->cipher->set_ctx_params(ctx->provctx, params);
      return 0;
  }
  
  int EVP_CIPHER_CTX_get_params(EVP_CIPHER_CTX *ctx, OSSL_PARAM params[])
  {
      if (ctx->cipher != NULL && ctx->cipher->get_ctx_params != NULL)
          return ctx->cipher->get_ctx_params(ctx->provctx, params);
      return 0;
  }
  
  const OSSL_PARAM *EVP_CIPHER_gettable_params(const EVP_CIPHER *cipher)
  {
      if (cipher != NULL && cipher->gettable_params != NULL)
          return cipher->gettable_params(
                     ossl_provider_ctx(EVP_CIPHER_provider(cipher)));
      return NULL;
  }
  
  const OSSL_PARAM *EVP_CIPHER_settable_ctx_params(const EVP_CIPHER *cipher)
  {
      if (cipher != NULL && cipher->settable_ctx_params != NULL)
          return cipher->settable_ctx_params(
                     ossl_provider_ctx(EVP_CIPHER_provider(cipher)));
      return NULL;
  }
  
  const OSSL_PARAM *EVP_CIPHER_gettable_ctx_params(const EVP_CIPHER *cipher)
  {
      if (cipher != NULL && cipher->gettable_ctx_params != NULL)
          return cipher->gettable_ctx_params(
                     ossl_provider_ctx(EVP_CIPHER_provider(cipher)));
      return NULL;
  }
  
  #ifndef FIPS_MODULE
  static OSSL_LIB_CTX *EVP_CIPHER_CTX_get_libctx(EVP_CIPHER_CTX *ctx)
  {
      const EVP_CIPHER *cipher = ctx->cipher;
      const OSSL_PROVIDER *prov;
  
      if (cipher == NULL)
          return NULL;
  
      prov = EVP_CIPHER_provider(cipher);
      return ossl_provider_libctx(prov);
  }
  #endif
  
  int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
  {
      if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
          return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
  
  #ifdef FIPS_MODULE
      return 0;
  #else
      {
          int kl;
          OSSL_LIB_CTX *libctx = EVP_CIPHER_CTX_get_libctx(ctx);
  
          kl = EVP_CIPHER_CTX_key_length(ctx);
          if (kl <= 0 || RAND_priv_bytes_ex(libctx, key, kl) <= 0)
              return 0;
          return 1;
      }
  #endif /* FIPS_MODULE */
  }
  
  int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
  {
      if ((in == NULL) || (in->cipher == NULL)) {
          ERR_raise(ERR_LIB_EVP, EVP_R_INPUT_NOT_INITIALIZED);
          return 0;
      }
  
      if (in->cipher->prov == NULL)
          goto legacy;
  
      if (in->cipher->dupctx == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NOT_ABLE_TO_COPY_CTX);
          return 0;
      }
  
      EVP_CIPHER_CTX_reset(out);
  
      *out = *in;
      out->provctx = NULL;
  
      if (in->fetched_cipher != NULL && !EVP_CIPHER_up_ref(in->fetched_cipher)) {
          out->fetched_cipher = NULL;
          return 0;
      }
  
      out->provctx = in->cipher->dupctx(in->provctx);
      if (out->provctx == NULL) {
          ERR_raise(ERR_LIB_EVP, EVP_R_NOT_ABLE_TO_COPY_CTX);
          return 0;
      }
  
      return 1;
  
      /* TODO(3.0): Remove legacy code below */
   legacy:
  
  #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)
      /* Make sure it's safe to copy a cipher context using an ENGINE */
      if (in->engine && !ENGINE_init(in->engine)) {
          ERR_raise(ERR_LIB_EVP, ERR_R_ENGINE_LIB);
          return 0;
      }
  #endif
  
      EVP_CIPHER_CTX_reset(out);
      memcpy(out, in, sizeof(*out));
  
      if (in->cipher_data && in->cipher->ctx_size) {
          out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
          if (out->cipher_data == NULL) {
              out->cipher = NULL;
              ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
      }
  
      if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
          if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
              out->cipher = NULL;
              ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
              return 0;
          }
      return 1;
  }
  
  EVP_CIPHER *evp_cipher_new(void)
  {
      EVP_CIPHER *cipher = OPENSSL_zalloc(sizeof(EVP_CIPHER));
  
      if (cipher != NULL) {
          cipher->lock = CRYPTO_THREAD_lock_new();
          if (cipher->lock == NULL) {
              OPENSSL_free(cipher);
              return NULL;
          }
          cipher->refcnt = 1;
      }
      return cipher;
  }
  
  /*
   * FIPS module note: since internal fetches will be entirely
   * provider based, we know that none of its code depends on legacy
   * NIDs or any functionality that use them.
   */
  #ifndef FIPS_MODULE
  /* TODO(3.x) get rid of the need for legacy NIDs */
  static void set_legacy_nid(const char *name, void *vlegacy_nid)
  {
      int nid;
      int *legacy_nid = vlegacy_nid;
      /*
       * We use lowest level function to get the associated method, because
       * higher level functions such as EVP_get_cipherbyname() have changed
       * to look at providers too.
       */
      const void *legacy_method = OBJ_NAME_get(name, OBJ_NAME_TYPE_CIPHER_METH);
  
      if (*legacy_nid == -1)       /* We found a clash already */
          return;
      if (legacy_method == NULL)
          return;
      nid = EVP_CIPHER_nid(legacy_method);
      if (*legacy_nid != NID_undef && *legacy_nid != nid) {
          *legacy_nid = -1;
          return;
      }
      *legacy_nid = nid;
  }
  #endif
  
  static void *evp_cipher_from_dispatch(const int name_id,
                                        const OSSL_DISPATCH *fns,
                                        OSSL_PROVIDER *prov)
  {
      EVP_CIPHER *cipher = NULL;
      int fnciphcnt = 0, fnctxcnt = 0;
  
      if ((cipher = evp_cipher_new()) == NULL) {
          ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
          return NULL;
      }
  
  #ifndef FIPS_MODULE
      /* TODO(3.x) get rid of the need for legacy NIDs */
      cipher->nid = NID_undef;
      evp_names_do_all(prov, name_id, set_legacy_nid, &cipher->nid);
      if (cipher->nid == -1) {
          ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
          EVP_CIPHER_free(cipher);
          return NULL;
      }
  #endif
  
      cipher->name_id = name_id;
  
      for (; fns->function_id != 0; fns++) {
          switch (fns->function_id) {
          case OSSL_FUNC_CIPHER_NEWCTX:
              if (cipher->newctx != NULL)
                  break;
              cipher->newctx = OSSL_FUNC_cipher_newctx(fns);
              fnctxcnt++;
              break;
          case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
              if (cipher->einit != NULL)
                  break;
              cipher->einit = OSSL_FUNC_cipher_encrypt_init(fns);
              fnciphcnt++;
              break;
          case OSSL_FUNC_CIPHER_DECRYPT_INIT:
              if (cipher->dinit != NULL)
                  break;
              cipher->dinit = OSSL_FUNC_cipher_decrypt_init(fns);
              fnciphcnt++;
              break;
          case OSSL_FUNC_CIPHER_UPDATE:
              if (cipher->cupdate != NULL)
                  break;
              cipher->cupdate = OSSL_FUNC_cipher_update(fns);
              fnciphcnt++;
              break;
          case OSSL_FUNC_CIPHER_FINAL:
              if (cipher->cfinal != NULL)
                  break;
              cipher->cfinal = OSSL_FUNC_cipher_final(fns);
              fnciphcnt++;
              break;
          case OSSL_FUNC_CIPHER_CIPHER:
              if (cipher->ccipher != NULL)
                  break;
              cipher->ccipher = OSSL_FUNC_cipher_cipher(fns);
              break;
          case OSSL_FUNC_CIPHER_FREECTX:
              if (cipher->freectx != NULL)
                  break;
              cipher->freectx = OSSL_FUNC_cipher_freectx(fns);
              fnctxcnt++;
              break;
          case OSSL_FUNC_CIPHER_DUPCTX:
              if (cipher->dupctx != NULL)
                  break;
              cipher->dupctx = OSSL_FUNC_cipher_dupctx(fns);
              break;
          case OSSL_FUNC_CIPHER_GET_PARAMS:
              if (cipher->get_params != NULL)
                  break;
              cipher->get_params = OSSL_FUNC_cipher_get_params(fns);
              break;
          case OSSL_FUNC_CIPHER_GET_CTX_PARAMS:
              if (cipher->get_ctx_params != NULL)
                  break;
              cipher->get_ctx_params = OSSL_FUNC_cipher_get_ctx_params(fns);
              break;
          case OSSL_FUNC_CIPHER_SET_CTX_PARAMS:
              if (cipher->set_ctx_params != NULL)
                  break;
              cipher->set_ctx_params = OSSL_FUNC_cipher_set_ctx_params(fns);
              break;
          case OSSL_FUNC_CIPHER_GETTABLE_PARAMS:
              if (cipher->gettable_params != NULL)
                  break;
              cipher->gettable_params = OSSL_FUNC_cipher_gettable_params(fns);
              break;
          case OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS:
              if (cipher->gettable_ctx_params != NULL)
                  break;
              cipher->gettable_ctx_params =
                  OSSL_FUNC_cipher_gettable_ctx_params(fns);
              break;
          case OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS:
              if (cipher->settable_ctx_params != NULL)
                  break;
              cipher->settable_ctx_params =
                  OSSL_FUNC_cipher_settable_ctx_params(fns);
              break;
          }
      }
      if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
              || (fnciphcnt == 0 && cipher->ccipher == NULL)
              || fnctxcnt != 2) {
          /*
           * In order to be a consistent set of functions we must have at least
           * a complete set of "encrypt" functions, or a complete set of "decrypt"
           * functions, or a single "cipher" function. In all cases we need both
           * the "newctx" and "freectx" functions.
           */
          EVP_CIPHER_free(cipher);
          ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
          return NULL;
      }
      cipher->prov = prov;
      if (prov != NULL)
          ossl_provider_up_ref(prov);
  
      return cipher;
  }
  
  static int evp_cipher_up_ref(void *cipher)
  {
      return EVP_CIPHER_up_ref(cipher);
  }
  
  static void evp_cipher_free(void *cipher)
  {
      EVP_CIPHER_free(cipher);
  }
  
  EVP_CIPHER *EVP_CIPHER_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
                               const char *properties)
  {
      EVP_CIPHER *cipher =
          evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
                            evp_cipher_from_dispatch, evp_cipher_up_ref,
                            evp_cipher_free);
  
      if (cipher != NULL && !evp_cipher_cache_constants(cipher)) {
          EVP_CIPHER_free(cipher);
          cipher = NULL;
      }
      return cipher;
  }
  
  int EVP_CIPHER_up_ref(EVP_CIPHER *cipher)
  {
      int ref = 0;
  
      CRYPTO_UP_REF(&cipher->refcnt, &ref, cipher->lock);
      return 1;
  }
  
  void EVP_CIPHER_free(EVP_CIPHER *cipher)
  {
      int i;
  
      if (cipher == NULL)
          return;
  
      CRYPTO_DOWN_REF(&cipher->refcnt, &i, cipher->lock);
      if (i > 0)
          return;
      ossl_provider_free(cipher->prov);
      CRYPTO_THREAD_lock_free(cipher->lock);
      OPENSSL_free(cipher);
  }
  
  void EVP_CIPHER_do_all_provided(OSSL_LIB_CTX *libctx,
                                  void (*fn)(EVP_CIPHER *mac, void *arg),
                                  void *arg)
  {
      evp_generic_do_all(libctx, OSSL_OP_CIPHER,
                         (void (*)(void *, void *))fn, arg,
                         evp_cipher_from_dispatch, evp_cipher_free);
  }
  