/src/cryptopp/hmac.h

Source (jump to first uncovered line)
// hmac.h - originally written and placed in the public domain by Wei Dai

/// \file hmac.h
/// \brief Classes for HMAC message authentication codes

#ifndef CRYPTOPP_HMAC_H
#define CRYPTOPP_HMAC_H

#include "seckey.h"
#include "secblock.h"

NAMESPACE_BEGIN(CryptoPP)

/// \brief HMAC information
/// \details HMAC_Base derives from VariableKeyLength and MessageAuthenticationCode
/// \since Crypto++ 2.1
class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE HMAC_Base : public VariableKeyLength<16, 0, INT_MAX>, public MessageAuthenticationCode
{
public:
  virtual ~HMAC_Base() {}

  /// \brief Construct a HMAC_Base
  HMAC_Base() : m_innerHashKeyed(false) {}
  void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params);

  void Restart();
  void Update(const byte *input, size_t length);
  void TruncatedFinal(byte *mac, size_t size);
  unsigned int OptimalBlockSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().OptimalBlockSize();}
  unsigned int DigestSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().DigestSize();}

protected:
  virtual HashTransformation & AccessHash() =0;
  byte * AccessIpad() {return m_buf;}
  byte * AccessOpad() {return m_buf + AccessHash().BlockSize();}
  byte * AccessInnerHash() {return m_buf + 2*AccessHash().BlockSize();}

private:
  void KeyInnerHash();

  SecByteBlock m_buf;
  bool m_innerHashKeyed;
};

/// \brief HMAC
/// \tparam T HashTransformation derived class
/// \details HMAC derives from MessageAuthenticationCodeImpl. It calculates the HMAC using
///   <tt>HMAC(K, text) = H(K XOR opad, H(K XOR ipad, text))</tt>.
/// \sa <a href="http://www.weidai.com/scan-mirror/mac.html#HMAC">HMAC</a>
/// \since Crypto++ 2.1
template <class T>
class HMAC : public MessageAuthenticationCodeImpl<HMAC_Base, HMAC<T> >
{
public:
  CRYPTOPP_CONSTANT(DIGESTSIZE=T::DIGESTSIZE);
  CRYPTOPP_CONSTANT(BLOCKSIZE=T::BLOCKSIZE);

  virtual ~HMAC() {}

  /// \brief Construct a HMAC
  HMAC() {}
  /// \brief Construct a HMAC
  /// \param key the HMAC key
  /// \param length the size of the HMAC key
  HMAC(const byte *key, size_t length=HMAC_Base::DEFAULT_KEYLENGTH)
    {this->SetKey(key, length);}

  static std::string StaticAlgorithmName() {return std::string("HMAC(") + T::StaticAlgorithmName() + ")";}
  std::string AlgorithmName() const {return std::string("HMAC(") + m_hash.AlgorithmName() + ")";}
  std::string AlgorithmProvider() const {return m_hash.AlgorithmProvider();}

private:
  HashTransformation & AccessHash() {return m_hash;}

  T m_hash;
};

NAMESPACE_END

#endif

Coverage Report

Created: 2024-11-21 07:03