poco/Foundation/include/Poco/HMACEngine.h

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//
// HMACEngine.h
//
// $Id: //poco/1.4/Foundation/include/Poco/HMACEngine.h#1 $
//
// Library: Foundation
// Package: Crypt
// Module: HMACEngine
//
// Definition of the HMACEngine class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_HMACEngine_INCLUDED
#define Foundation_HMACEngine_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/DigestEngine.h"
#include <cstring>
namespace Poco {
template <class Engine>
class HMACEngine: public DigestEngine
/// This class implementes the HMAC message
/// authentication code algorithm, as specified
/// in RFC 2104. The underlying DigestEngine
/// (MD5Engine, SHA1Engine, etc.) must be given as
/// template argument.
/// Since the HMACEngine is a DigestEngine, it can
/// be used with the DigestStream class to create
/// a HMAC for a stream.
{
public:
enum
{
BLOCK_SIZE = Engine::BLOCK_SIZE,
DIGEST_SIZE = Engine::DIGEST_SIZE
};
HMACEngine(const std::string& passphrase)
{
init(passphrase.data(), passphrase.length());
}
HMACEngine(const char* passphrase, std::size_t length)
{
poco_check_ptr (passphrase);
init(passphrase, length);
}
~HMACEngine()
{
std::memset(_ipad, 0, BLOCK_SIZE);
std::memset(_opad, 0, BLOCK_SIZE);
delete [] _ipad;
delete [] _opad;
}
std::size_t digestLength() const
{
return DIGEST_SIZE;
}
void reset()
{
_engine.reset();
_engine.update(_ipad, BLOCK_SIZE);
}
const DigestEngine::Digest& digest()
{
const DigestEngine::Digest& d = _engine.digest();
char db[DIGEST_SIZE];
char* pdb = db;
for (DigestEngine::Digest::const_iterator it = d.begin(); it != d.end(); ++it)
*pdb++ = *it;
_engine.reset();
_engine.update(_opad, BLOCK_SIZE);
_engine.update(db, DIGEST_SIZE);
const DigestEngine::Digest& result = _engine.digest();
reset();
return result;
}
protected:
void init(const char* passphrase, std::size_t length)
{
_ipad = new char[BLOCK_SIZE];
_opad = new char[BLOCK_SIZE];
std::memset(_ipad, 0, BLOCK_SIZE);
std::memset(_opad, 0, BLOCK_SIZE);
if (length > BLOCK_SIZE)
{
_engine.reset();
_engine.update(passphrase, length);
const DigestEngine::Digest& d = _engine.digest();
char* ipad = _ipad;
char* opad = _opad;
int n = BLOCK_SIZE;
for (DigestEngine::Digest::const_iterator it = d.begin(); it != d.end() && n-- > 0; ++it)
{
*ipad++ = *it;
*opad++ = *it;
}
}
else
{
std::memcpy(_ipad, passphrase, length);
std::memcpy(_opad, passphrase, length);
}
for (int i = 0; i < BLOCK_SIZE; ++i)
{
_ipad[i] ^= 0x36;
_opad[i] ^= 0x5c;
}
reset();
}
void updateImpl(const void* data, std::size_t length)
{
_engine.update(data, length);
}
private:
HMACEngine();
HMACEngine(const HMACEngine&);
HMACEngine& operator = (const HMACEngine&);
Engine _engine;
char* _ipad;
char* _opad;
};
} // namespace Poco
#endif // Foundation_HMACEngine_INCLUDED