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/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2006 Tatsuhiro Tsujikawa
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#ifndef D_MSE_HANDSHAKE_H
#define D_MSE_HANDSHAKE_H
#include "common.h"
#include <vector>
#include "SharedHandle.h"
#include "BtConstants.h"
#include "SocketBuffer.h"
#include "Command.h"
namespace aria2 {
class Option;
class SocketCore;
class DHKeyExchange;
class ARC4Encryptor;
class DownloadContext;
class MessageDigest;
class MSEHandshake {
public:
enum HANDSHAKE_TYPE {
HANDSHAKE_NOT_YET = 0,
HANDSHAKE_LEGACY,
HANDSHAKE_ENCRYPTED
};
enum CRYPTO_TYPE {
CRYPTO_NONE = 0,
CRYPTO_PLAIN_TEXT = 0x01u,
CRYPTO_ARC4 = 0x02u
};
private:
static const size_t PRIME_BITS = 768U;
static const size_t KEY_LENGTH = (PRIME_BITS+7U)/8U;
static const size_t VC_LENGTH = 8U;
// The largest buffering occurs when receiver receives step2
// handshake. We believe that IA is less than or equal to
// BtHandshakeMessage::MESSAGE_LENGTH
static const size_t MAX_BUFFER_LENGTH = 636U;
cuid_t cuid_;
SharedHandle<SocketCore> socket_;
bool wantRead_;
const Option* option_;
unsigned char rbuf_[MAX_BUFFER_LENGTH];
size_t rbufLength_;
SocketBuffer socketBuffer_;
CRYPTO_TYPE negotiatedCryptoType_;
DHKeyExchange* dh_;
SharedHandle<ARC4Encryptor> encryptor_;
SharedHandle<ARC4Encryptor> decryptor_;
unsigned char infoHash_[INFO_HASH_LENGTH];
unsigned char secret_[KEY_LENGTH];
bool initiator_;
unsigned char initiatorVCMarker_[VC_LENGTH];
size_t markerIndex_;
uint16_t padLength_;
uint16_t iaLength_;
unsigned char* ia_;
SharedHandle<MessageDigest> sha1_;
void encryptAndSendData(unsigned char* data, size_t length);
void createReq1Hash(unsigned char* md) const;
void createReq23Hash(unsigned char* md, const unsigned char* infoHash) const;
uint16_t decodeLength16(const unsigned char* buffer);
uint16_t decodeLength16(const char* buffer)
{
return decodeLength16(reinterpret_cast<const unsigned char*>(buffer));
}
uint16_t verifyPadLength(const unsigned char* padlenbuf,
const char* padName);
void verifyVC(unsigned char* vcbuf);
void verifyReq1Hash(const unsigned char* req1buf);
void shiftBuffer(size_t offset);
public:
MSEHandshake(cuid_t cuid, const SharedHandle<SocketCore>& socket,
const Option* op);
~MSEHandshake();
HANDSHAKE_TYPE identifyHandshakeType();
void initEncryptionFacility(bool initiator);
// Reads data from Socket. If EOF is reached, throws
// RecoverableException.
void read();
// Sends pending data in the send buffer. Returns true if all data
// is sent. Otherwise returns false.
bool send();
bool getWantRead() const
{
return wantRead_;
}
void setWantRead(bool wantRead)
{
wantRead_ = wantRead;
}
bool getWantWrite() const;
void sendPublicKey();
bool receivePublicKey();
void initCipher(const unsigned char* infoHash);
void sendInitiatorStep2();
bool findInitiatorVCMarker();
bool receiveInitiatorCryptoSelectAndPadDLength();
bool receivePad();
bool findReceiverHashMarker();
bool receiveReceiverHashAndPadCLength
(const std::vector<SharedHandle<DownloadContext> >& downloadContexts);
bool receiveReceiverIALength();
bool receiveReceiverIA();
void sendReceiverStep2();
// returns plain text IA
const unsigned char* getIA() const
{
return ia_;
}
size_t getIALength() const
{
return iaLength_;
}
const unsigned char* getInfoHash() const
{
return infoHash_;
}
CRYPTO_TYPE getNegotiatedCryptoType() const
{
return negotiatedCryptoType_;
}
const SharedHandle<ARC4Encryptor>& getEncryptor() const
{
return encryptor_;
}
const SharedHandle<ARC4Encryptor>& getDecryptor() const
{
return decryptor_;
}
const unsigned char* getBuffer() const
{
return rbuf_;
}
unsigned char* getBuffer()
{
return rbuf_;
}
size_t getBufferLength() const
{
return rbufLength_;
}
};
} // namespace aria2
#endif // D_MSE_HANDSHAKE_H
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