salsa.h
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// salsa.h - written and placed in the public domain by Wei Dai
//! \file salsa.h
//! \brief Classes for Salsa and Salsa20 stream ciphers
#ifndef CRYPTOPP_SALSA_H
#define CRYPTOPP_SALSA_H
#include "strciphr.h"
#include "secblock.h"
// TODO: work around GCC 4.8+ issue with SSE2 ASM until the exact details are known
// and fix is released. Duplicate with "valgrind ./cryptest.exe tv salsa"
// "Inline assembly operands don't work with .intel_syntax", http://llvm.org/bugs/show_bug.cgi?id=24232
#if CRYPTOPP_BOOL_X32 || defined(CRYPTOPP_DISABLE_INTEL_ASM) || (CRYPTOPP_GCC_VERSION >= 40800)
# define CRYPTOPP_DISABLE_SALSA_ASM
#endif
NAMESPACE_BEGIN(CryptoPP)
//! \class Salsa20_Info
//! \brief Salsa20 stream cipher information
struct Salsa20_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
{
CRYPTOPP_CONSTEXPR static const char *StaticAlgorithmName() {return "Salsa20";}
};
//! \class Salsa20_Policy
//! \brief Salsa20 stream cipher operation
class CRYPTOPP_NO_VTABLE Salsa20_Policy : 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);
#if (CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64) && !defined(CRYPTOPP_DISABLE_SALSA_ASM)
unsigned int GetAlignment() const;
unsigned int GetOptimalBlockSize() const;
#endif
FixedSizeAlignedSecBlock<word32, 16> m_state;
int m_rounds;
};
//! \class Salsa20
//! \brief Salsa20 stream cipher
//! \details Salsa20 provides a variable number of rounds: 8, 12 or 20. The default number of rounds is 20.
//! \sa <a href="http://www.cryptolounge.org/wiki/XSalsa20">XSalsa20</a>
struct Salsa20 : public Salsa20_Info, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<Salsa20_Policy, AdditiveCipherTemplate<> >, Salsa20_Info> Encryption;
typedef Encryption Decryption;
};
//! \class XSalsa20_Info
//! \brief XSalsa20 stream cipher information
struct XSalsa20_Info : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 24>
{
CRYPTOPP_CONSTEXPR static const char *StaticAlgorithmName() {return "XSalsa20";}
};
//! \class XSalsa20_Policy
//! \brief XSalsa20 stream cipher operation
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;
};
//! \class XSalsa20
//! \brief XSalsa20 stream cipher
//! \details XSalsa20 provides a variable number of rounds: 8, 12 or 20. The default number of rounds is 20.
//! \sa <a href="http://www.cryptolounge.org/wiki/XSalsa20">XSalsa20</a>
struct XSalsa20 : public XSalsa20_Info, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<XSalsa20_Policy, AdditiveCipherTemplate<> >, XSalsa20_Info> Encryption;
typedef Encryption Decryption;
};
NAMESPACE_END
#endif
AdditiveCipherAbstractPolicy::CipherIsRandomAccess
virtual bool CipherIsRandomAccess() const =0
Flag indicating random access.
FixedSizeAlignedSecBlock< word32, 16 >
AdditiveCipherAbstractPolicy::CipherResynchronize
virtual void CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)
Resynchronize the cipher.
Definition: strciphr.h:166
SymmetricCipherDocumentation
Provides Encryption and Decryption typedefs used by derived classes to implement a symmetric cipher.
Definition: seckey.h:439
SymmetricCipherFinal
SymmetricCipher implementation.
Definition: strciphr.h:582
AdditiveCipherConcretePolicy
Base class for additive stream ciphers.
Definition: strciphr.h:188
AdditiveCipherAbstractPolicy::CipherSetKey
virtual void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)=0
Key the cipher.
secblock.h
Classes and functions for secure memory allocations.
SimpleKeyingInterface
Interface for algorithms that take byte strings as keys.
Definition: cryptlib.h:524
Salsa20_Info
Salsa20 stream cipher information.
Definition: salsa.h:23
FixedKeyLength
Inherited by keyed algorithms with fixed key length.
Definition: seckey.h:128
KeystreamOperation
KeystreamOperation
Keystream operation flags.
Definition: strciphr.h:92
XSalsa20_Policy
XSalsa20 stream cipher operation.
Definition: salsa.h:66
FixedSizeSecBlock< word32, 8 >
Salsa20_Policy
Salsa20 stream cipher operation.
Definition: salsa.h:30
XSalsa20_Info
XSalsa20 stream cipher information.
Definition: salsa.h:59
CryptoPP
Crypto++ library namespace.
AdditiveCipherAbstractPolicy::SeekToIteration
virtual void SeekToIteration(lword iterationCount)
Seeks to a random position in the stream.
Definition: strciphr.h:177
AdditiveCipherConcretePolicy::GetAlignment
unsigned int GetAlignment() const
Provides data alignment requirements.
Definition: strciphr.h:198
XSalsa20
XSalsa20 stream cipher.
Definition: salsa.h:80
AdditiveCipherConcretePolicy::OperateKeystream
virtual void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)=0
Operates the keystream.
AdditiveCipherAbstractPolicy::GetOptimalBlockSize
virtual unsigned int GetOptimalBlockSize() const
Provides number of ideal bytes to process.
Definition: strciphr.h:127
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:277
strciphr.h
Classes for implementing stream ciphers.
Salsa20
Salsa20 stream cipher.
Definition: salsa.h:51
VariableKeyLength
Inherited by keyed algorithms with variable key length.
Definition: seckey.h:177