salsa.h

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// salsa.h - originally written and placed in the public domain by Wei Dai
 
 
#ifndef CRYPTOPP_SALSA_H
#define CRYPTOPP_SALSA_H
 
#include "strciphr.h"
#include "secblock.h"
 
// Clang 3.3 integrated assembler crash on Linux. Clang 3.4 due to compiler
// error with .intel_syntax, http://llvm.org/bugs/show_bug.cgi?id=24232
#if CRYPTOPP_BOOL_X32 || defined(CRYPTOPP_DISABLE_MIXED_ASM)
# define CRYPTOPP_DISABLE_SALSA_ASM 1
#endif
 
NAMESPACE_BEGIN(CryptoPP)
 
 
void Salsa20_Core(word32* data, unsigned int rounds);
 
struct Salsa20_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
{
        static std::string StaticAlgorithmName() {return "Salsa20";}
};
 
class CRYPTOPP_NO_VTABLE Salsa20_Policy : public AdditiveCipherConcretePolicy<word32, 16>
{
protected:
        Salsa20_Policy() : m_rounds(ROUNDS) {}
        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);
 
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)
        unsigned int GetAlignment() const;
        unsigned int GetOptimalBlockSize() const;
#endif
 
        std::string AlgorithmProvider() const;
 
        CRYPTOPP_CONSTANT(ROUNDS = 20);  // Default rounds
        FixedSizeAlignedSecBlock<word32, 16> m_state;
        int m_rounds;
};
 
struct Salsa20 : public Salsa20_Info, public SymmetricCipherDocumentation
{
        typedef SymmetricCipherFinal<ConcretePolicyHolder<Salsa20_Policy, AdditiveCipherTemplate<> >, Salsa20_Info> Encryption;
        typedef Encryption Decryption;
};
 
struct XSalsa20_Info : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 24>
{
        static std::string StaticAlgorithmName() {return "XSalsa20";}
};
 
class CRYPTOPP_NO_VTABLE XSalsa20_Policy : public Salsa20_Policy
{
public:
        void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
        void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
 
protected:
        FixedSizeSecBlock<word32, 8> m_key;
};
 
struct XSalsa20 : public XSalsa20_Info, public SymmetricCipherDocumentation
{
        typedef SymmetricCipherFinal<ConcretePolicyHolder<XSalsa20_Policy, AdditiveCipherTemplate<> >, XSalsa20_Info> Encryption;
        typedef Encryption Decryption;
};
 
NAMESPACE_END
 
#endif