1 files changed, 61 insertions, 0 deletions

diff --git a/CryptoPP/hmac.h b/CryptoPP/hmac.h
new file mode 100644
index 000000000..62db5ef33
--- /dev/null
+++ b/CryptoPP/hmac.h
@@ -0,0 +1,61 @@
+// hmac.h - written and placed in the public domain by Wei Dai
+
+#ifndef CRYPTOPP_HMAC_H
+#define CRYPTOPP_HMAC_H
+
+#include "seckey.h"
+#include "secblock.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+//! _
+class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE HMAC_Base : public VariableKeyLength<16, 0, INT_MAX>, public MessageAuthenticationCode
+{
+public:
+	HMAC_Base() : m_innerHashKeyed(false) {}
+	void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params);
+
+	void Restart();
+	void Update(const byte *input, size_t length);
+	void TruncatedFinal(byte *mac, size_t size);
+	unsigned int OptimalBlockSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().OptimalBlockSize();}
+	unsigned int DigestSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().DigestSize();}
+
+protected:
+	virtual HashTransformation & AccessHash() =0;
+	byte * AccessIpad() {return m_buf;}
+	byte * AccessOpad() {return m_buf + AccessHash().BlockSize();}
+	byte * AccessInnerHash() {return m_buf + 2*AccessHash().BlockSize();}
+
+private:
+	void KeyInnerHash();
+
+	SecByteBlock m_buf;
+	bool m_innerHashKeyed;
+};
+
+//! <a href="http://www.weidai.com/scan-mirror/mac.html#HMAC">HMAC</a>
+/*! HMAC(K, text) = H(K XOR opad, H(K XOR ipad, text)) */
+template <class T>
+class HMAC : public MessageAuthenticationCodeImpl<HMAC_Base, HMAC<T> >
+{
+public:
+	CRYPTOPP_CONSTANT(DIGESTSIZE=T::DIGESTSIZE)
+	CRYPTOPP_CONSTANT(BLOCKSIZE=T::BLOCKSIZE)
+
+	HMAC() {}
+	HMAC(const byte *key, size_t length=HMAC_Base::DEFAULT_KEYLENGTH)
+		{this->SetKey(key, length);}
+
+	static std::string StaticAlgorithmName() {return std::string("HMAC(") + T::StaticAlgorithmName() + ")";}
+	std::string AlgorithmName() const {return std::string("HMAC(") + m_hash.AlgorithmName() + ")";}
+
+private:
+	HashTransformation & AccessHash() {return m_hash;}
+
+	T m_hash;
+};
+
+NAMESPACE_END
+
+#endif