add Salsa20 cipher

1 files changed, 43 insertions, 0 deletions

diff --git a/salsa.h b/salsa.h
new file mode 100755
index 00000000..dd66d157
--- /dev/null
+++ b/salsa.h
@@ -0,0 +1,43 @@
+// salsa.h - written and placed in the public domain by Wei Dai
+
+#ifndef CRYPTOPP_SALSA_H
+#define CRYPTOPP_SALSA_H
+
+#include "strciphr.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+//! _
+struct Salsa20_Info : public VariableKeyLength<32, 16, 32, 16, SimpleKeyingInterface::STRUCTURED_IV>
+{
+	static const char *StaticAlgorithmName() {return "Salsa20";}
+};
+
+class CRYPTOPP_NO_VTABLE Salsa20_Policy : public AdditiveCipherConcretePolicy<word32, 16>, public Salsa20_Info
+{
+public:
+	unsigned int IVSize() const {return 8;}
+	void GetNextIV(byte *IV) const;
+
+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);
+	bool IsRandomAccess() const {return true;}
+	void SeekToIteration(lword iterationCount);
+
+private:
+	int m_rounds;
+	FixedSizeSecBlock<word32, 16> m_state;
+};
+
+//! Salsa20, variable rounds: 8, 12 or 20 (default 20)
+struct Salsa20 : public Salsa20_Info, public SymmetricCipherDocumentation
+{
+	typedef SymmetricCipherFinal<ConcretePolicyHolder<Salsa20_Policy, AdditiveCipherTemplate<> >, Salsa20_Info> Encryption;
+	typedef Encryption Decryption;
+};
+
+NAMESPACE_END
+
+#endif