00001
00002
00003 #ifndef CRYPTOPP_HMAC_H
00004 #define CRYPTOPP_HMAC_H
00005
00006 #include "seckey.h"
00007 #include "secblock.h"
00008
00009 NAMESPACE_BEGIN(CryptoPP)
00010
00011
00012 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE HMAC_Base : public VariableKeyLength<16, 0, INT_MAX>, public MessageAuthenticationCode
00013 {
00014 public:
00015 HMAC_Base() : m_innerHashKeyed(false) {}
00016 void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs ¶ms);
00017
00018 void Restart();
00019 void Update(const byte *input, size_t length);
00020 void TruncatedFinal(byte *mac, size_t size);
00021 unsigned int OptimalBlockSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().OptimalBlockSize();}
00022 unsigned int DigestSize() const {return const_cast<HMAC_Base*>(this)->AccessHash().DigestSize();}
00023
00024 protected:
00025 virtual HashTransformation & AccessHash() =0;
00026 byte * AccessIpad() {return m_buf;}
00027 byte * AccessOpad() {return m_buf + AccessHash().BlockSize();}
00028 byte * AccessInnerHash() {return m_buf + 2*AccessHash().BlockSize();}
00029
00030 private:
00031 void KeyInnerHash();
00032
00033 SecByteBlock m_buf;
00034 bool m_innerHashKeyed;
00035 };
00036
00037
00038
00039 template <class T>
00040 class HMAC : public MessageAuthenticationCodeImpl<HMAC_Base, HMAC<T> >
00041 {
00042 public:
00043 CRYPTOPP_CONSTANT(DIGESTSIZE=T::DIGESTSIZE)
00044 CRYPTOPP_CONSTANT(BLOCKSIZE=T::BLOCKSIZE)
00045
00046 HMAC() {}
00047 HMAC(const byte *key, size_t length=HMAC_Base::DEFAULT_KEYLENGTH)
00048 {this->SetKey(key, length);}
00049
00050 static std::string StaticAlgorithmName() {return std::string("HMAC(") + T::StaticAlgorithmName() + ")";}
00051 std::string AlgorithmName() const {return std::string("HMAC(") + m_hash.AlgorithmName() + ")";}
00052
00053 private:
00054 HashTransformation & AccessHash() {return m_hash;}
00055
00056 T m_hash;
00057 };
00058
00059 NAMESPACE_END
00060
00061 #endif