/* Copyright (c) 2007-2018, Un Shyam & Arvid Norberg 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_PE_CRYPTO_HPP_INCLUDED #define TORRENT_PE_CRYPTO_HPP_INCLUDED #if !defined TORRENT_DISABLE_ENCRYPTION #include "libtorrent/config.hpp" #include "libtorrent/aux_/disable_warnings_push.hpp" #include #include "libtorrent/aux_/disable_warnings_pop.hpp" #include "libtorrent/receive_buffer.hpp" #include "libtorrent/sha1_hash.hpp" #include "libtorrent/extensions.hpp" #include "libtorrent/assert.hpp" #include "libtorrent/span.hpp" #include "libtorrent/buffer.hpp" #include "libtorrent/aux_/array.hpp" #include #include #include namespace libtorrent { namespace mp = boost::multiprecision; using key_t = mp::number>; TORRENT_EXTRA_EXPORT std::array export_key(key_t const& k); // RC4 state from libtomcrypt struct rc4 { int x; int y; aux::array buf; }; // TODO: 3 dh_key_exchange should probably move into its own file class TORRENT_EXTRA_EXPORT dh_key_exchange { public: dh_key_exchange(); bool good() const { return true; } // Get local public key key_t const& get_local_key() const { return m_dh_local_key; } // read remote_pubkey, generate and store shared secret in // m_dh_shared_secret. void compute_secret(std::uint8_t const* remote_pubkey); void compute_secret(key_t const& remote_pubkey); key_t const& get_secret() const { return m_dh_shared_secret; } sha1_hash const& get_hash_xor_mask() const { return m_xor_mask; } private: key_t m_dh_local_key; key_t m_dh_local_secret; key_t m_dh_shared_secret; sha1_hash m_xor_mask; }; struct TORRENT_EXTRA_EXPORT encryption_handler { std::tuple>> encrypt(span> iovec); int decrypt(crypto_receive_buffer& recv_buffer , std::size_t& bytes_transferred); bool switch_send_crypto(std::shared_ptr crypto , int pending_encryption); void switch_recv_crypto(std::shared_ptr crypto , crypto_receive_buffer& recv_buffer); bool is_send_plaintext() const { return m_send_barriers.empty() || m_send_barriers.back().next != INT_MAX; } bool is_recv_plaintext() const { return m_dec_handler.get() == nullptr; } private: struct barrier { barrier(std::shared_ptr plugin, int n) : enc_handler(plugin), next(n) {} std::shared_ptr enc_handler; // number of bytes to next barrier int next; }; std::list m_send_barriers; std::shared_ptr m_dec_handler; }; struct TORRENT_EXTRA_EXPORT rc4_handler : crypto_plugin { public: rc4_handler(); // Input keys must be 20 bytes void set_incoming_key(span key) override; void set_outgoing_key(span key) override; std::tuple>> encrypt(span> buf) override; std::tuple decrypt(span> buf) override; private: rc4 m_rc4_incoming; rc4 m_rc4_outgoing; // determines whether or not encryption and decryption is enabled bool m_encrypt; bool m_decrypt; }; } // namespace libtorrent #endif // TORRENT_DISABLE_ENCRYPTION #endif // TORRENT_PE_CRYPTO_HPP_INCLUDED