mirror of
https://github.com/shadps4-emu/ext-cryptopp.git
synced 2024-11-23 09:59:42 +00:00
86 lines
3.6 KiB
C++
86 lines
3.6 KiB
C++
// chacha.h - written and placed in the public domain by Jeffrey Walton.
|
|
// Based on Wei Dai's Salsa20, Botan's SSE2 implementation,
|
|
// and Bernstein's reference ChaCha family implementation at
|
|
// http://cr.yp.to/chacha.html.
|
|
|
|
/// \file chacha.h
|
|
/// \brief Classes for ChaCha8, ChaCha12 and ChaCha20 stream ciphers
|
|
/// \details Crypto++ provides Bernstein and ECRYPT's ChaCha from <a href="http://cr.yp.to/chacha/chacha-20080128.pdf">ChaCha,
|
|
/// a variant of Salsa20</a> (2008.01.28). Bernstein's implementation is _slightly_ different from the TLS working group's
|
|
/// implementation for cipher suites <tt>TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
|
|
/// <tt>TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256</tt>, and <tt>TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>.
|
|
/// \since Crypto++ 5.6.4
|
|
|
|
#ifndef CRYPTOPP_CHACHA_H
|
|
#define CRYPTOPP_CHACHA_H
|
|
|
|
#include "strciphr.h"
|
|
#include "secblock.h"
|
|
|
|
NAMESPACE_BEGIN(CryptoPP)
|
|
|
|
/// \brief ChaCha stream cipher information
|
|
/// \since Crypto++ 5.6.4
|
|
struct ChaCha_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
|
|
{
|
|
/// \brief The algorithm name
|
|
/// \returns the algorithm name
|
|
/// \details StaticAlgorithmName returns the algorithm's name as a static
|
|
/// member function.
|
|
/// \details Bernstein named the cipher variants ChaCha8, ChaCha12 and
|
|
/// ChaCha20. More generally, Bernstein called the family ChaCha{r}.
|
|
/// AlgorithmName() provides the exact name once rounds are set.
|
|
static const char* StaticAlgorithmName() {
|
|
return "ChaCha";
|
|
}
|
|
};
|
|
|
|
/// \brief ChaCha stream cipher implementation
|
|
/// \since Crypto++ 5.6.4
|
|
class CRYPTOPP_NO_VTABLE ChaCha_Policy : public AdditiveCipherConcretePolicy<word32, 16>
|
|
{
|
|
public:
|
|
~ChaCha_Policy() {}
|
|
ChaCha_Policy() : m_rounds(0) {}
|
|
|
|
protected:
|
|
void CipherSetKey(const NameValuePairs ¶ms, 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;
|
|
|
|
std::string AlgorithmName() const;
|
|
std::string AlgorithmProvider() const;
|
|
|
|
// MultiBlockSafe detects a condition that can arise in the SIMD
|
|
// implementations where we overflow one of the 32-bit state words
|
|
// during addition in an intermediate result. Conditions to trigger
|
|
// issue include a user seeks to around 2^32 blocks (256 GB of data).
|
|
// https://github.com/weidai11/cryptopp/issues/732
|
|
inline bool MultiBlockSafe(unsigned int blocks) const;
|
|
|
|
FixedSizeAlignedSecBlock<word32, 16> m_state;
|
|
unsigned int m_rounds;
|
|
};
|
|
|
|
/// \brief ChaCha stream cipher
|
|
/// \details Bernstein and ECRYPT's ChaCha is _slightly_ different from the TLS working
|
|
/// group's implementation for cipher suites
|
|
/// <tt>TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
|
|
/// <tt>TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256</tt>, and
|
|
/// <tt>TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>.
|
|
/// \sa <a href="http://cr.yp.to/chacha/chacha-20080208.pdf">ChaCha, a variant of Salsa20</a> (2008.01.28).
|
|
/// \since Crypto++ 5.6.4
|
|
struct ChaCha : public ChaCha_Info, public SymmetricCipherDocumentation
|
|
{
|
|
typedef SymmetricCipherFinal<ConcretePolicyHolder<ChaCha_Policy, AdditiveCipherTemplate<> >, ChaCha_Info > Encryption;
|
|
typedef Encryption Decryption;
|
|
};
|
|
|
|
NAMESPACE_END
|
|
|
|
#endif // CRYPTOPP_CHACHA_H
|