hmac.h
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// 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
HMAC_Base
HMAC information.
Definition hmac.h:18
HMAC_Base::OptimalBlockSize
unsigned int OptimalBlockSize() const
Provides the input block size most efficient for this hash.
Definition hmac.h:29
HMAC_Base::UncheckedSetKey
void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params)
Sets the key for this object without performing parameter validation.
HMAC_Base::TruncatedFinal
void TruncatedFinal(byte *mac, size_t size)
Computes the hash of the current message.
HMAC_Base::Restart
void Restart()
Restart the hash.
HMAC_Base::HMAC_Base
HMAC_Base()
Construct a HMAC_Base.
Definition hmac.h:23
HMAC_Base::DigestSize
unsigned int DigestSize() const
Provides the digest size of the hash.
Definition hmac.h:30
HMAC_Base::Update
void Update(const byte *input, size_t length)
Updates a hash with additional input.
HMAC
HMAC.
Definition hmac.h:53
HMAC::HMAC
HMAC(const byte *key, size_t length=HMAC_Base::DEFAULT_KEYLENGTH)
Construct a HMAC.
Definition hmac.h:65
HMAC::HMAC
HMAC()
Construct a HMAC.
Definition hmac.h:61
HashTransformation
Interface for hash functions and data processing part of MACs.
Definition cryptlib.h:1118
HashTransformation::BlockSize
virtual unsigned int BlockSize() const
Provides the block size of the compression function.
Definition cryptlib.h:1170
MessageAuthenticationCode
Interface for message authentication codes.
Definition cryptlib.h:1304
MessageAuthenticationCodeImpl
Provides a base implementation of Algorithm and SimpleKeyingInterface for message authentication code...
Definition seckey.h:363
NameValuePairs
Interface for retrieving values given their names.
Definition cryptlib.h:327
SecByteBlock
SecBlock<byte> typedef.
Definition secblock.h:1226
VariableKeyLength
Inherited by keyed algorithms with variable key length.
Definition seckey.h:166
VariableKeyLength< 16, 0, INT_MAX >::DEFAULT_KEYLENGTH
static const int DEFAULT_KEYLENGTH
The default key length used by the algorithm provided as a constant.
Definition seckey.h:184
CryptoPP
Crypto++ library namespace.
secblock.h
Classes and functions for secure memory allocations.
seckey.h
Classes and functions for implementing secret key algorithms.