539364846a
git-svn-id: http://mc-server.googlecode.com/svn/trunk@808 0a769ca7-a7f5-676a-18bf-c427514a06d6
94 lines
2.5 KiB
C++
94 lines
2.5 KiB
C++
#ifndef CRYPTOPP_DMAC_H
|
|
#define CRYPTOPP_DMAC_H
|
|
|
|
#include "cbcmac.h"
|
|
|
|
NAMESPACE_BEGIN(CryptoPP)
|
|
|
|
//! _
|
|
template <class T>
|
|
class CRYPTOPP_NO_VTABLE DMAC_Base : public SameKeyLengthAs<T>, public MessageAuthenticationCode
|
|
{
|
|
public:
|
|
static std::string StaticAlgorithmName() {return std::string("DMAC(") + T::StaticAlgorithmName() + ")";}
|
|
|
|
CRYPTOPP_CONSTANT(DIGESTSIZE=T::BLOCKSIZE)
|
|
|
|
DMAC_Base() {}
|
|
|
|
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms);
|
|
void Update(const byte *input, size_t length);
|
|
void TruncatedFinal(byte *mac, size_t size);
|
|
unsigned int DigestSize() const {return DIGESTSIZE;}
|
|
|
|
private:
|
|
byte *GenerateSubKeys(const byte *key, size_t keylength);
|
|
|
|
size_t m_subkeylength;
|
|
SecByteBlock m_subkeys;
|
|
CBC_MAC<T> m_mac1;
|
|
typename T::Encryption m_f2;
|
|
unsigned int m_counter;
|
|
};
|
|
|
|
//! DMAC
|
|
/*! Based on "CBC MAC for Real-Time Data Sources" by Erez Petrank
|
|
and Charles Rackoff. T should be a class derived from BlockCipherDocumentation.
|
|
*/
|
|
template <class T>
|
|
class DMAC : public MessageAuthenticationCodeFinal<DMAC_Base<T> >
|
|
{
|
|
public:
|
|
DMAC() {}
|
|
DMAC(const byte *key, size_t length=DMAC_Base<T>::DEFAULT_KEYLENGTH)
|
|
{this->SetKey(key, length);}
|
|
};
|
|
|
|
template <class T>
|
|
void DMAC_Base<T>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
|
|
{
|
|
m_subkeylength = T::StaticGetValidKeyLength(T::BLOCKSIZE);
|
|
m_subkeys.resize(2*UnsignedMin((unsigned int)T::BLOCKSIZE, m_subkeylength));
|
|
m_mac1.SetKey(GenerateSubKeys(key, length), m_subkeylength, params);
|
|
m_f2.SetKey(m_subkeys+m_subkeys.size()/2, m_subkeylength, params);
|
|
m_counter = 0;
|
|
m_subkeys.resize(0);
|
|
}
|
|
|
|
template <class T>
|
|
void DMAC_Base<T>::Update(const byte *input, size_t length)
|
|
{
|
|
m_mac1.Update(input, length);
|
|
m_counter = (unsigned int)((m_counter + length) % T::BLOCKSIZE);
|
|
}
|
|
|
|
template <class T>
|
|
void DMAC_Base<T>::TruncatedFinal(byte *mac, size_t size)
|
|
{
|
|
ThrowIfInvalidTruncatedSize(size);
|
|
|
|
byte pad[T::BLOCKSIZE];
|
|
byte padByte = byte(T::BLOCKSIZE-m_counter);
|
|
memset(pad, padByte, padByte);
|
|
m_mac1.Update(pad, padByte);
|
|
m_mac1.TruncatedFinal(mac, size);
|
|
m_f2.ProcessBlock(mac);
|
|
|
|
m_counter = 0; // reset for next message
|
|
}
|
|
|
|
template <class T>
|
|
byte *DMAC_Base<T>::GenerateSubKeys(const byte *key, size_t keylength)
|
|
{
|
|
typename T::Encryption cipher(key, keylength);
|
|
memset(m_subkeys, 0, m_subkeys.size());
|
|
cipher.ProcessBlock(m_subkeys);
|
|
m_subkeys[m_subkeys.size()/2 + T::BLOCKSIZE - 1] = 1;
|
|
cipher.ProcessBlock(m_subkeys+m_subkeys.size()/2);
|
|
return m_subkeys;
|
|
}
|
|
|
|
NAMESPACE_END
|
|
|
|
#endif
|