// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "secure_hash.h"

#if defined(OPENSSL_IS_BORINGSSL)
#include <openssl/mem.h>
#else
#include <openssl/crypto.h>
#endif
#include <openssl/sha.h>
#include <stddef.h>

#include <android-base/logging.h>

namespace crypto {

namespace {

class SecureHashSHA256 : public SecureHash {
 public:
  SecureHashSHA256() {
    SHA256_Init(&ctx_);
  }

  SecureHashSHA256(const SecureHashSHA256& other) : SecureHash() {
    memcpy(&ctx_, &other.ctx_, sizeof(ctx_));
  }

  ~SecureHashSHA256() override {
    OPENSSL_cleanse(&ctx_, sizeof(ctx_));
  }

  void Update(const void* input, size_t len) override {
    SHA256_Update(&ctx_, static_cast<const unsigned char*>(input), len);
  }

  void Finish(void* output, size_t len) override {
    CHECK(len >= SHA256_DIGEST_LENGTH);
    SHA256_Final(static_cast<uint8_t*>(output), &ctx_);
  }

  SecureHash* Clone() const override {
    return new SecureHashSHA256(*this);
  }

  size_t GetHashLength() const override { return SHA256_DIGEST_LENGTH; }

 private:
  SHA256_CTX ctx_;
};

}  // namespace

SecureHash* SecureHash::Create(Algorithm algorithm) {
  switch (algorithm) {
    case SHA256:
      return new SecureHashSHA256();
    default:
      LOG(ERROR) << "SecureHash not implemented for algorithm " << algorithm;
      return NULL;
  }
}

}  // namespace crypto