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Add ChaCha family of stream ciphers

pull/157/head
Jeffrey Walton 2016-04-21 12:08:21 -04:00
parent 53b51331a4
commit d4d418503f
1 changed files with 67 additions and 0 deletions
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// chacha.h - written and placed in the public domain by Jeffrey Walton.
// Copyright assigned to the Crypto++ project.
//! \file chacha.h
//! \brief Classes for ChaCha8, ChaCha12 and ChaCha stream ciphers
#ifndef CRYPTOPP_CHACHA_H
#define CRYPTOPP_CHACHA_H
#include "strciphr.h"
#include "secblock.h"
NAMESPACE_BEGIN(CryptoPP)
//! \class ChaCha_Info
//! \brief ChaCha stream cipher information
template <unsigned int R>
struct ChaCha_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>, public FixedRounds<R>
{
static const char *StaticAlgorithmName() {return "ChaCha";}
};
template <unsigned int R>
class CRYPTOPP_NO_VTABLE ChaCha_Base : public AdditiveCipherConcretePolicy<word32, 16>
{
protected:
void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
bool CipherIsRandomAccess() const {return true;}
void SeekToIteration(lword iterationCount);
unsigned int GetAlignment() const;
unsigned int GetOptimalBlockSize() const;
FixedSizeAlignedSecBlock<word32, 16> m_state;
};
//! \class ChaCha8
//! \brief ChaCha8 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28).
struct ChaCha8 : public ChaCha_Info<8>, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<8>, AdditiveCipherTemplate<> >, ChaCha_Info<8> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<8>, AdditiveCipherTemplate<> >, ChaCha_Info<8> > Decryption;
};
//! \class ChaCha12
//! \brief ChaCha12 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28).
struct ChaCha12 : public ChaCha_Info<12>, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<12>, AdditiveCipherTemplate<> >, ChaCha_Info<12> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<12>, AdditiveCipherTemplate<> >, ChaCha_Info<12> > Decryption;
};
//! \class ChaCha20
//! \brief ChaCha20 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28).
struct ChaCha20 : public ChaCha_Info<20>, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<20>, AdditiveCipherTemplate<> >, ChaCha_Info<20> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Base<20>, AdditiveCipherTemplate<> >, ChaCha_Info<20> > Decryption;
};
NAMESPACE_END
#endif // CRYPTOPP_CHACHA_H