crypto/secure_hash.h

// 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.
//
// This interface is deprecated and being removed: https://crbug.com/374310081.
// New users should use crypto/hash instead.

#ifndef CRYPTO_SECURE_HASH_H_
#define CRYPTO_SECURE_HASH_H_

#include <stddef.h>

#include <memory>

#include "base/containers/span.h"
#include "crypto/crypto_export.h"

namespace crypto {

// A wrapper to calculate secure hashes incrementally, allowing to
// be used when the full input is not known in advance. The end result will the
// same as if we have the full input in advance.
//
// TODO(https://issues.chromium.org/issues/374310081): Delete this.
class CRYPTO_EXPORT SecureHash {
 public:
  enum Algorithm {
    SHA256,
    SHA512,
  };

  SecureHash(const SecureHash&) = delete;
  SecureHash& operator=(const SecureHash&) = delete;

  virtual ~SecureHash() {}

  static std::unique_ptr<SecureHash> Create(Algorithm type);

  virtual void Update(base::span<const uint8_t> input) = 0;
  virtual void Finish(base::span<uint8_t> output) = 0;

  virtual size_t GetHashLength() const = 0;

  // Create a clone of this SecureHash. The returned clone and this both
  // represent the same hash state. But from this point on, calling
  // Update()/Finish() on either doesn't affect the state of the other.
  virtual std::unique_ptr<SecureHash> Clone() const = 0;

 protected:
  SecureHash() {}
};

}  // namespace crypto

#endif  // CRYPTO_SECURE_HASH_H_