// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/digest.h>

#include <assert.h>

#include <string.h>

#include <openssl/err.h>

#include <openssl/mem.h>

#include "../../internal.h"

#include "../../mem_internal.h"

#include "internal.h"

using namespace bssl;

int EVP_MD_type(const EVP_MD *md) { return md->type; }

int EVP_MD_nid(const EVP_MD *md) { return EVP_MD_type(md); }

uint32_t EVP_MD_flags(const EVP_MD *md) { return md->flags; }

size_t EVP_MD_size(const EVP_MD *md) { return md->md_size; }

size_t EVP_MD_block_size(const EVP_MD *md) { return md->block_size; }

void EVP_MD_CTX_init(EVP_MD_CTX *ctx) {

  ctx->digest = nullptr;

  ctx->pctx = nullptr;

  ctx->pctx_ops = nullptr;

}

EVP_MD_CTX *EVP_MD_CTX_new() {

  EVP_MD_CTX *ctx = New<EVP_MD_CTX>();

  if (ctx) {

    EVP_MD_CTX_init(ctx);

  }

  return ctx;

}

EVP_MD_CTX *EVP_MD_CTX_create() { return EVP_MD_CTX_new(); }

int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx) {

  assert(ctx->pctx == nullptr || ctx->pctx_ops != nullptr);

  if (ctx->pctx_ops) {

    ctx->pctx_ops->free(ctx->pctx);

  }

  EVP_MD_CTX_init(ctx);

  return 1;

}

void EVP_MD_CTX_cleanse(EVP_MD_CTX *ctx) {

  OPENSSL_cleanse(ctx->md_data, sizeof(ctx->md_data));

  EVP_MD_CTX_cleanup(ctx);

}

void EVP_MD_CTX_free(EVP_MD_CTX *ctx) {

  if (!ctx) {

    return;

  }

  EVP_MD_CTX_cleanup(ctx);

  Delete(ctx);

}

void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx) { EVP_MD_CTX_free(ctx); }

int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, uint8_t *out, size_t len) {

  OPENSSL_PUT_ERROR(DIGEST, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);

  return 0;

}

uint32_t EVP_MD_meth_get_flags(const EVP_MD *md) { return EVP_MD_flags(md); }

void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, int flags) {}

int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in) {

  // `in->digest` may be NULL if this is a signing `EVP_MD_CTX` for, e.g.,

  // Ed25519 which does not hash with `EVP_MD_CTX`.

  if (in == nullptr || (in->pctx == nullptr && in->digest == nullptr)) {

    OPENSSL_PUT_ERROR(DIGEST, DIGEST_R_INPUT_NOT_INITIALIZED);

    return 0;

  }

  if (out == in) {

    OPENSSL_PUT_ERROR(DIGEST, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);

    return 0;

  }

  EVP_PKEY_CTX *pctx = nullptr;

  assert(in->pctx == nullptr || in->pctx_ops != nullptr);

  if (in->pctx) {

    pctx = in->pctx_ops->dup(in->pctx);

    if (!pctx) {

      return 0;

    }

  }

  EVP_MD_CTX_cleanup(out);

  out->digest = in->digest;

  if (in->digest != nullptr) {

    OPENSSL_memcpy(out->md_data, in->md_data, in->digest->ctx_size);

  }

  out->pctx = pctx;

  out->pctx_ops = in->pctx_ops;

  assert(out->pctx == nullptr || out->pctx_ops != nullptr);

  return 1;

}

void EVP_MD_CTX_move(EVP_MD_CTX *out, EVP_MD_CTX *in) {

  EVP_MD_CTX_cleanup(out);

  // While not guaranteed, `EVP_MD_CTX` is currently safe to move with `memcpy`.

  // bssl-crypto currently relies on this, however, so if we change this, we

  // need to box the `HMAC_CTX`. (Relying on this is only fine because we assume

  // BoringSSL and bssl-crypto will always be updated atomically. We do not

  // allow any version skew between the two.)

  OPENSSL_memcpy(out, in, sizeof(EVP_MD_CTX));

  EVP_MD_CTX_init(in);

}

int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in) {

  EVP_MD_CTX_init(out);

  return EVP_MD_CTX_copy_ex(out, in);

}

int EVP_MD_CTX_reset(EVP_MD_CTX *ctx) {

  EVP_MD_CTX_cleanup(ctx);

  EVP_MD_CTX_init(ctx);

  return 1;

}

int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *engine) {

  EVP_MD_CTX_cleanup(ctx);

  assert(ctx->pctx == nullptr);

  assert(type->ctx_size != 0);

  assert(type->ctx_size <= sizeof(ctx->md_data));

  ctx->digest = type;

  ctx->digest->init(ctx);

  return 1;

}

int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type) {

  EVP_MD_CTX_init(ctx);

  return EVP_DigestInit_ex(ctx, type, nullptr);

}

int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t len) {

  ctx->digest->update(ctx, data, len);

  return 1;

}

int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, uint8_t *md_out, unsigned int *size) {

  assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);

  ctx->digest->final(ctx, md_out);

  if (size != nullptr) {

    *size = ctx->digest->md_size;

  }

  OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);

  return 1;

}

int EVP_DigestFinal(EVP_MD_CTX *ctx, uint8_t *md, unsigned int *size) {

  (void)EVP_DigestFinal_ex(ctx, md, size);

  EVP_MD_CTX_cleanup(ctx);

  return 1;

}

int EVP_Digest(const void *data, size_t count, uint8_t *out_md,

               unsigned int *out_size, const EVP_MD *type, ENGINE *impl) {

  ScopedEVP_MD_CTX ctx;

  return EVP_DigestInit_ex(ctx.get(), type, impl) &&

         EVP_DigestUpdate(ctx.get(), data, count) &&

         EVP_DigestFinal_ex(ctx.get(), out_md, out_size);

}

const EVP_MD *EVP_MD_CTX_get0_md(const EVP_MD_CTX *ctx) {

  if (ctx == nullptr) {

    return nullptr;

  }

  return ctx->digest;

}

const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx) {

  return EVP_MD_CTX_get0_md(ctx);

}

size_t EVP_MD_CTX_size(const EVP_MD_CTX *ctx) {

  return EVP_MD_size(EVP_MD_CTX_get0_md(ctx));

}

size_t EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx) {

  return EVP_MD_block_size(EVP_MD_CTX_get0_md(ctx));

}

int EVP_MD_CTX_type(const EVP_MD_CTX *ctx) {

  return EVP_MD_type(EVP_MD_CTX_get0_md(ctx));

}

EVP_PKEY_CTX *EVP_MD_CTX_pkey_ctx(const EVP_MD_CTX *ctx) { return ctx->pctx; }

int EVP_add_digest(const EVP_MD *digest) { return 1; }