1// salsa.h - written and placed in the public domain by Wei Dai
2
3#ifndef CRYPTOPP_SALSA_H
4#define CRYPTOPP_SALSA_H
5
6#include "strciphr.h"
7
8NAMESPACE_BEGIN(CryptoPP)
9
10//! _
11struct Salsa20_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::UNIQUE_IV, 8>
12{
13	static const char *StaticAlgorithmName() {return "Salsa20";}
14};
15
16class CRYPTOPP_NO_VTABLE Salsa20_Policy : public AdditiveCipherConcretePolicy<word32, 16>
17{
18protected:
19	void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
20	void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
21	void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
22	bool CipherIsRandomAccess() const {return true;}
23	void SeekToIteration(lword iterationCount);
24#if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X64
25	unsigned int GetAlignment() const;
26	unsigned int GetOptimalBlockSize() const;
27#endif
28
29	FixedSizeAlignedSecBlock<word32, 16> m_state;
30	int m_rounds;
31};
32
33/// <a href="http://www.cryptolounge.org/wiki/Salsa20">Salsa20</a>, variable rounds: 8, 12 or 20 (default 20)
34struct Salsa20 : public Salsa20_Info, public SymmetricCipherDocumentation
35{
36	typedef SymmetricCipherFinal<ConcretePolicyHolder<Salsa20_Policy, AdditiveCipherTemplate<> >, Salsa20_Info> Encryption;
37	typedef Encryption Decryption;
38};
39
40//! _
41struct XSalsa20_Info : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 24>
42{
43	static const char *StaticAlgorithmName() {return "XSalsa20";}
44};
45
46class CRYPTOPP_NO_VTABLE XSalsa20_Policy : public Salsa20_Policy
47{
48public:
49	void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
50	void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
51
52protected:
53	FixedSizeSecBlock<word32, 8> m_key;
54};
55
56/// <a href="http://www.cryptolounge.org/wiki/XSalsa20">XSalsa20</a>, variable rounds: 8, 12 or 20 (default 20)
57struct XSalsa20 : public XSalsa20_Info, public SymmetricCipherDocumentation
58{
59	typedef SymmetricCipherFinal<ConcretePolicyHolder<XSalsa20_Policy, AdditiveCipherTemplate<> >, XSalsa20_Info> Encryption;
60	typedef Encryption Decryption;
61};
62
63NAMESPACE_END
64
65#endif
66