128 lines
3.6 KiB
C++
128 lines
3.6 KiB
C++
/*
|
|
|
|
Copyright (c) 2007, Un Shyam
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the distribution.
|
|
* Neither the name of the author nor the names of its
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_DISABLE_ENCRYPTION
|
|
|
|
#ifndef TORRENT_PE_CRYPTO_HPP_INCLUDED
|
|
#define TORRENT_PE_CRYPTO_HPP_INCLUDED
|
|
|
|
#include <openssl/dh.h>
|
|
#include <openssl/engine.h>
|
|
#include <openssl/rc4.h>
|
|
|
|
#include "libtorrent/peer_id.hpp" // For sha1_hash
|
|
#include "libtorrent/assert.hpp"
|
|
|
|
namespace libtorrent
|
|
{
|
|
class dh_key_exchange
|
|
{
|
|
public:
|
|
dh_key_exchange();
|
|
~dh_key_exchange();
|
|
bool good() const { return m_dh; }
|
|
|
|
// Get local public key, always 96 bytes
|
|
char const* get_local_key() const;
|
|
|
|
// read remote_pubkey, generate and store shared secret in
|
|
// m_dh_secret.
|
|
int compute_secret(const char* remote_pubkey);
|
|
|
|
char const* get_secret() const { return m_dh_secret; }
|
|
|
|
sha1_hash const& get_hash_xor_mask() const { return m_xor_mask; }
|
|
|
|
private:
|
|
int get_local_key_size() const
|
|
{
|
|
TORRENT_ASSERT(m_dh);
|
|
return BN_num_bytes(m_dh->pub_key);
|
|
}
|
|
|
|
DH* m_dh;
|
|
|
|
char m_dh_local_key[96];
|
|
char m_dh_secret[96];
|
|
sha1_hash m_xor_mask;
|
|
};
|
|
|
|
class RC4_handler // Non copyable
|
|
{
|
|
public:
|
|
// Input longkeys must be 20 bytes
|
|
RC4_handler(const sha1_hash& rc4_local_longkey,
|
|
const sha1_hash& rc4_remote_longkey)
|
|
|
|
{
|
|
RC4_set_key(&m_local_key, 20,
|
|
reinterpret_cast<unsigned char const*>(rc4_local_longkey.begin()));
|
|
RC4_set_key(&m_remote_key, 20,
|
|
reinterpret_cast<unsigned char const*>(rc4_remote_longkey.begin()));
|
|
|
|
// Discard first 1024 bytes
|
|
char buf[1024];
|
|
encrypt(buf, 1024);
|
|
decrypt(buf, 1024);
|
|
};
|
|
|
|
~RC4_handler() {};
|
|
|
|
void encrypt(char* pos, int len)
|
|
{
|
|
TORRENT_ASSERT(len >= 0);
|
|
TORRENT_ASSERT(pos);
|
|
|
|
RC4 (&m_local_key, len, reinterpret_cast<unsigned char const*>(pos),
|
|
reinterpret_cast<unsigned char*>(pos));
|
|
}
|
|
|
|
void decrypt(char* pos, int len)
|
|
{
|
|
TORRENT_ASSERT(len >= 0);
|
|
TORRENT_ASSERT(pos);
|
|
|
|
RC4 (&m_remote_key, len, reinterpret_cast<unsigned char const*>(pos),
|
|
reinterpret_cast<unsigned char*>(pos));
|
|
}
|
|
|
|
private:
|
|
RC4_KEY m_local_key; // Key to encrypt outgoing data
|
|
RC4_KEY m_remote_key; // Key to decrypt incoming data
|
|
};
|
|
|
|
} // namespace libtorrent
|
|
|
|
#endif // TORRENT_PE_CRYPTO_HPP_INCLUDED
|
|
#endif // TORRENT_DISABLE_ENCRYPTION
|
|
|