// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_CRYPTO_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_CRYPTO_H_

#include "base/containers/span.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/hash_functions.h"
#include "third_party/blink/renderer/platform/wtf/text/string_hasher.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"
#include "third_party/boringssl/src/include/openssl/digest.h"

namespace blink {

static const size_t kMaxDigestSize = 64;
typedef Vector<uint8_t, kMaxDigestSize> DigestValue;

enum HashAlgorithm {
  kHashAlgorithmSha1,
  kHashAlgorithmSha256,
  kHashAlgorithmSha384,
  kHashAlgorithmSha512
};

PLATFORM_EXPORT bool ComputeDigest(HashAlgorithm,
                                   const char* digestable,
                                   size_t length,
                                   DigestValue& digest_result);

class PLATFORM_EXPORT Digestor {
 public:
  explicit Digestor(HashAlgorithm);
  ~Digestor();

  bool has_failed() const { return has_failed_; }

  // Return false on failure. These do nothing once the |has_failed_| flag is
  // set. This object cannot be reused; do not update it after Finish.
  bool Update(base::span<const uint8_t>);
  bool UpdateUtf8(const String&,
                  WTF::UTF8ConversionMode = WTF::kLenientUTF8Conversion);
  bool Finish(DigestValue&);

 private:
  bssl::ScopedEVP_MD_CTX digest_context_;
  bool has_failed_ = false;
};

}  // namespace blink

namespace WTF {

struct DigestValueHash {
  STATIC_ONLY(DigestValueHash);
  static unsigned GetHash(const blink::DigestValue& v) {
    return StringHasher::ComputeHash(v.data(), v.size());
  }
  static bool Equal(const blink::DigestValue& a, const blink::DigestValue& b) {
    return a == b;
  }
  static const bool safe_to_compare_to_empty_or_deleted = true;
};
template <>
struct DefaultHash<blink::DigestValue> {
  STATIC_ONLY(DefaultHash);
  typedef DigestValueHash Hash;
};

template <>
struct DefaultHash<blink::HashAlgorithm> {
  STATIC_ONLY(DefaultHash);
  typedef IntHash<blink::HashAlgorithm> Hash;
};
template <>
struct HashTraits<blink::HashAlgorithm>
    : UnsignedWithZeroKeyHashTraits<blink::HashAlgorithm> {
  STATIC_ONLY(HashTraits);
};

}  // namespace WTF

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_CRYPTO_H_