arne
/
cryptopp
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Adjusted ChaCha for dynamic round selection 

I've adjusted the ChaCha code to allow selection of the round number at
run-time and to improve readibility (slightly)
pull/157/head
DevJPM 2016-04-21 23:16:23 +02:00
parent da05d100e3
commit 275afb4955
2 changed files with 49 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
chacha.cpp
View File

@ -27,8 +27,7 @@ void ChaCha_TestInstantiations()
} }
#endif #endif
template <unsigned int R> void ChaCha_Policy::CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)
void ChaCha_Policy<R>::CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)
{ {
CRYPTOPP_UNUSED(params); CRYPTOPP_UNUSED(params);
assert(length == 16 || length == 32); assert(length == 16 || length == 32);
@ -46,8 +45,7 @@ void ChaCha_Policy<R>::CipherSetKey(const NameValuePairs &params, const byte *ke
get2(m_state[8])(m_state[9])(m_state[10])(m_state[11]); get2(m_state[8])(m_state[9])(m_state[10])(m_state[11]);
} }
template <unsigned int R> void ChaCha_Policy::CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length)
void ChaCha_Policy<R>::CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length)
{ {
CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length); CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
assert(length==8); assert(length==8);
@ -57,8 +55,7 @@ void ChaCha_Policy<R>::CipherResynchronize(byte *keystreamBuffer, const byte *IV
get(m_state[14])(m_state[15]); get(m_state[14])(m_state[15]);
} }
template<unsigned int R> void ChaCha_Policy::SeekToIteration(lword iterationCount)
void ChaCha_Policy<R>::SeekToIteration(lword iterationCount)
{ {
CRYPTOPP_UNUSED(iterationCount); CRYPTOPP_UNUSED(iterationCount);
throw NotImplemented(std::string(ChaCha_Info<R>::StaticAlgorithmName()) + ": SeekToIteration is not yet implemented"); throw NotImplemented(std::string(ChaCha_Info<R>::StaticAlgorithmName()) + ": SeekToIteration is not yet implemented");
@ -70,8 +67,7 @@ void ChaCha_Policy<R>::SeekToIteration(lword iterationCount)
// m_state[5] = (word32)SafeRightShift<32>(iterationCount); // m_state[5] = (word32)SafeRightShift<32>(iterationCount);
} }
template<unsigned int R> unsigned int ChaCha_Policy::GetAlignment() const
unsigned int ChaCha_Policy<R>::GetAlignment() const
{ {
#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE && 0 #if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE && 0
if (HasSSE2()) if (HasSSE2())
@ -81,8 +77,7 @@ unsigned int ChaCha_Policy<R>::GetAlignment() const
return GetAlignmentOf<word32>(); return GetAlignmentOf<word32>();
} }
template<unsigned int R> unsigned int ChaCha_Policy::GetOptimalBlockSize() const
unsigned int ChaCha_Policy<R>::GetOptimalBlockSize() const
{ {
#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE && 0 #if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE && 0
if (HasSSE2()) if (HasSSE2())
@ -92,8 +87,7 @@ unsigned int ChaCha_Policy<R>::GetOptimalBlockSize() const
return BYTES_PER_ITERATION; return BYTES_PER_ITERATION;
} }
template<unsigned int R> void ChaCha_Policy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
void ChaCha_Policy<R>::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
{ {
word32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; word32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
@ -104,7 +98,7 @@ void ChaCha_Policy<R>::OperateKeystream(KeystreamOperation operation, byte *outp
x8 = m_state[8]; x9 = m_state[9]; x10 = m_state[10]; x11 = m_state[11]; x8 = m_state[8]; x9 = m_state[9]; x10 = m_state[10]; x11 = m_state[11];
x12 = m_state[12]; x13 = m_state[13]; x14 = m_state[14]; x15 = m_state[15]; x12 = m_state[12]; x13 = m_state[13]; x14 = m_state[14]; x15 = m_state[15];
for (int i = static_cast<int>(ROUNDS); i > 0; i -= 2) for (int i = static_cast<int>(m_rounds); i > 0; i -= 2)
{ {
CHACHA_QUARTER_ROUND(x0, x4, x8, x12); CHACHA_QUARTER_ROUND(x0, x4, x8, x12);
CHACHA_QUARTER_ROUND(x1, x5, x9, x13); CHACHA_QUARTER_ROUND(x1, x5, x9, x13);

54
chacha.h
View File

@ -4,32 +4,37 @@
// family implementation at http://cr.yp.to/chacha.html. // family implementation at http://cr.yp.to/chacha.html.
//! \file chacha.h //! \file chacha.h
//! \brief Classes for ChaCha8, ChaCha12 and ChaCha20 stream ciphers //! \brief Classes for the ChaCha family of stream ciphers
#ifndef CRYPTOPP_CHACHA_H #ifndef CRYPTOPP_CHACHA_H
#define CRYPTOPP_CHACHA_H #define CRYPTOPP_CHACHA_H
#include "strciphr.h" #include "strciphr.h"
#include "secblock.h" #include "secblock.h"
#include "algparam.h" // for MakeParameters()
NAMESPACE_BEGIN(CryptoPP) NAMESPACE_BEGIN(CryptoPP)
//! \class ChaCha_Info //! \class ChaCha_Info
//! \brief ChaCha stream cipher information //! \brief ChaCha stream cipher information
struct ChaCha_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
{
static const char *StaticAlgorithmName() {static const std::string name = "ChaCha"; return name.c_str();}
};
//! \class ChaChaFR_Info
//! \brief ChaCha stream cipher information for compile-time fixed rounds
template<unsigned int R> template<unsigned int R>
struct ChaCha_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>, public FixedRounds<R> struct ChaChaFR_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>, public FixedRounds<R>
{ {
static const char *StaticAlgorithmName() { static const std::string name = "ChaCha" + IntToString(R); return name.c_str(); } static const char *StaticAlgorithmName() { static const std::string name = "ChaCha" + IntToString(R); return name.c_str(); }
}; };
//! \class ChaCha_Policy //! \class ChaCha_Policy
//! \brief ChaCha stream cipher implementation //! \brief ChaCha stream cipher implementation
template <unsigned int R>
class CRYPTOPP_NO_VTABLE ChaCha_Policy : public AdditiveCipherConcretePolicy<word32, 16> class CRYPTOPP_NO_VTABLE ChaCha_Policy : public AdditiveCipherConcretePolicy<word32, 16>
{ {
protected: protected:
CRYPTOPP_CONSTANT(ROUNDS=FixedRounds<R>::ROUNDS);
void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length); void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount); void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length); void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
@ -39,33 +44,54 @@ protected:
unsigned int GetOptimalBlockSize() const; unsigned int GetOptimalBlockSize() const;
FixedSizeAlignedSecBlock<word32, 16> m_state; FixedSizeAlignedSecBlock<word32, 16> m_state;
unsigned int m_rounds;
};
//! \class ChaCha_Policy
//! \brief ChaCha stream cipher implementation for fixed rounds
template<unsigned int R>
class CRYPTOPP_NO_VTABLE ChaChaFR_Policy : public ChaCha_Policy
{
protected:
CRYPTOPP_CONSTANT(ROUNDS = FixedRounds<R>::ROUNDS);
void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length) { CRYPTOPP_UNUSED(params); ChaCha_Policy::CipherSetKey(MakeParameters(Name::Rounds(), ROUNDS), key, length); }
}; };
//! \class ChaCha8 //! \class ChaCha8
//! \brief ChaCha8 stream cipher //! \brief ChaCha8 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28). //! \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 struct ChaCha8 : public ChaChaFR_Info<8>, public SymmetricCipherDocumentation
{ {
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<8>, AdditiveCipherTemplate<> >, ChaCha_Info<8> > Encryption; typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaChaFR_Policy<8>, AdditiveCipherTemplate<> >, ChaChaFR_Info<8> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<8>, AdditiveCipherTemplate<> >, ChaCha_Info<8> > Decryption; typedef Encryption Decryption;
}; };
//! \class ChaCha12 //! \class ChaCha12
//! \brief ChaCha12 stream cipher //! \brief ChaCha12 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28). //! \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 struct ChaCha12 : public ChaChaFR_Info<12>, public SymmetricCipherDocumentation
{ {
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<12>, AdditiveCipherTemplate<> >, ChaCha_Info<12> > Encryption; typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaChaFR_Policy<12>, AdditiveCipherTemplate<> >, ChaChaFR_Info<12> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<12>, AdditiveCipherTemplate<> >, ChaCha_Info<12> > Decryption; typedef Encryption Decryption;
}; };
//! \class ChaCha20 //! \class ChaCha20
//! \brief ChaCha20 stream cipher //! \brief ChaCha20 stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28). //! \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 struct ChaCha20 : public ChaChaFR_Info<20>, public SymmetricCipherDocumentation
{ {
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<20>, AdditiveCipherTemplate<> >, ChaCha_Info<20> > Encryption; typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaChaFR_Policy<20>, AdditiveCipherTemplate<> >, ChaChaFR_Info<20> > Encryption;
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy<20>, AdditiveCipherTemplate<> >, ChaCha_Info<20> > Decryption; typedef Encryption Decryption;
};
//! \class ChaCha
//! \brief ChaCha stream cipher
//! \sa <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28).
struct ChaCha : public ChaCha_Info, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy, AdditiveCipherTemplate<> >, ChaCha_Info > Encryption;
typedef Encryption Decryption;
}; };
NAMESPACE_END NAMESPACE_END