// This file Copyright (C) 2022 Mnemosyne LLC. // It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only), // or any future license endorsed by Mnemosyne LLC. // License text can be found in the licenses/ folder. #include #include #include #include #include // size_t, std::byte #include // uint8_t #include #include #include #include #include #ifdef _WIN32 #include #else #include #include // write() #endif #include #include #include // tr_sha1_to_string, tr_base... #include #include #include #include #include #include // tr_peerIdInit() #include #include #include #include #include "gtest/gtest.h" #include "test-fixtures.h" using namespace std::literals; #ifdef _WIN32 #define LOCAL_SOCKETPAIR_AF AF_INET #else #define LOCAL_SOCKETPAIR_AF AF_UNIX #endif namespace libtransmission::test { auto constexpr MaxWaitMsec = int{ 5000 }; class HandshakeTest : public SessionTest { public: class MediatorMock final : public tr_handshake::Mediator { public: explicit MediatorMock(tr_session* session) : session_{ session } { } [[nodiscard]] std::optional torrent(tr_sha1_digest_t const& info_hash) const override { if (auto const iter = torrents.find(info_hash); iter != std::end(torrents)) { return iter->second; } return {}; } [[nodiscard]] std::optional torrent_from_obfuscated(tr_sha1_digest_t const& obfuscated) const override { for (auto const& [info_hash, info] : torrents) { if (obfuscated == tr_sha1::digest("req2"sv, info.info_hash)) { return info; } } return {}; } [[nodiscard]] libtransmission::TimerMaker& timer_maker() override { return session_->timerMaker(); } [[nodiscard]] bool allows_dht() const override { return false; } [[nodiscard]] bool allows_tcp() const override { return true; } [[nodiscard]] size_t pad(void* setme, [[maybe_unused]] size_t maxlen) const override { TR_ASSERT(maxlen > 10); auto const len = size_t{ 10 }; std::fill_n(static_cast(setme), 10, ' '); return len; } [[nodiscard]] tr_message_stream_encryption::DH::private_key_bigend_t private_key() const override { return private_key_; } void set_utp_failed(tr_sha1_digest_t const& /*info_hash*/, tr_socket_address const& /*socket_address*/) override { } void setPrivateKeyFromBase64(std::string_view b64) { auto const str = tr_base64_decode(b64); assert(std::size(str) == std::size(private_key_)); std::copy_n(reinterpret_cast(std::data(str)), std::size(str), std::begin(private_key_)); } tr_session* const session_; std::map torrents; tr_message_stream_encryption::DH::private_key_bigend_t private_key_ = {}; }; template void sendToClient(evutil_socket_t sock, Span const& data) { auto const* walk = std::data(data); static_assert(sizeof(*walk) == 1); size_t len = std::size(data); while (len > 0) { #if defined(_WIN32) auto const n = send(sock, reinterpret_cast(walk), len, 0); #else auto const n = write(sock, walk, len); #endif assert(n >= 0); len -= n; walk += n; } } void sendB64ToClient(evutil_socket_t sock, std::string_view b64) { sendToClient(sock, tr_base64_decode(b64)); } static auto constexpr ReservedBytesNoExtensions = std::array{ 0, 0, 0, 0, 0, 0, 0, 0 }; static auto constexpr PlaintextProtocolName = "\023BitTorrent protocol"sv; tr_socket_address const DefaultPeerSockAddr{ *tr_address::from_string("127.0.0.1"sv), tr_port::from_host(8080) }; tr_handshake::Mediator::TorrentInfo const TorrentWeAreSeeding{ tr_sha1::digest("abcde"sv), tr_peerIdInit(), tr_torrent_id_t{ 100 }, true /*is_done*/ }; tr_handshake::Mediator::TorrentInfo const UbuntuTorrent{ *tr_sha1_from_string("2c6b6858d61da9543d4231a71db4b1c9264b0685"sv), tr_peerIdInit(), tr_torrent_id_t{ 101 }, false /*is_done*/ }; auto createIncomingIo(tr_session* session) { auto sockpair = std::array{ -1, -1 }; EXPECT_EQ(0, evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0, std::data(sockpair))) << tr_strerror(errno); return std::pair{ tr_peerIo::new_incoming( session, &session->top_bandwidth_, tr_peer_socket(session, DefaultPeerSockAddr, sockpair[0])), sockpair[1] }; } auto createOutgoingIo(tr_session* session, tr_sha1_digest_t const& info_hash) { auto sockpair = std::array{ -1, -1 }; EXPECT_EQ(0, evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0, std::data(sockpair))) << tr_strerror(errno); auto peer_io = tr_peerIo::create(session, &session->top_bandwidth_, &info_hash, false /*incoming*/, false /*seed*/); peer_io->set_socket(tr_peer_socket(session, DefaultPeerSockAddr, sockpair[0])); return std::pair{ std::move(peer_io), sockpair[1] }; } static constexpr auto makePeerId(std::string_view sv) { auto peer_id = tr_peer_id_t{}; for (size_t i = 0, n = std::size(sv); i < n; ++i) { peer_id[i] = sv[i]; } return peer_id; } static auto makeRandomPeerId() { auto peer_id = tr_rand_obj(); auto const peer_id_prefix = "-UW110Q-"sv; std::copy(std::begin(peer_id_prefix), std::end(peer_id_prefix), std::begin(peer_id)); return peer_id; } static auto runHandshake( tr_handshake::Mediator* mediator, std::shared_ptr const& peer_io, tr_encryption_mode encryption_mode = TR_CLEAR_PREFERRED) { auto result = std::optional{}; auto handshake = tr_handshake{ mediator, peer_io, encryption_mode, [&result](auto const& resin) { result = resin; return true; } }; waitFor([&result]() { return result.has_value(); }, MaxWaitMsec); return result; } }; TEST_F(HandshakeTest, incomingPlaintext) { auto const peer_id = makeRandomPeerId(); auto mediator = MediatorMock{ session_ }; mediator.torrents.emplace(TorrentWeAreSeeding.info_hash, TorrentWeAreSeeding); // The simplest handshake there is. "The handshake starts with character // nineteen (decimal) followed by the string 'BitTorrent protocol'. // The leading character is a length prefix[.]. After the fixed headers // come eight reserved bytes, which are all zero in all current // implementations[.] Next comes the 20 byte sha1 hash of the bencoded // form of the info value from the metainfo file[.] After the download // hash comes the 20-byte peer id which is reported in tracker requests // and contained in peer lists in tracker responses." // https://www.bittorrent.org/beps/bep_0052.html auto [io, sock] = createIncomingIo(session_); sendToClient(sock, PlaintextProtocolName); sendToClient(sock, ReservedBytesNoExtensions); sendToClient(sock, TorrentWeAreSeeding.info_hash); sendToClient(sock, peer_id); auto const res = runHandshake(&mediator, io); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_TRUE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(io, res->io); EXPECT_TRUE(res->peer_id); EXPECT_EQ(peer_id, res->peer_id); EXPECT_EQ(TorrentWeAreSeeding.info_hash, io->torrent_hash()); tr_net_close_socket(sock); } // The datastream is identical to HandshakeTest.incomingPlaintext, // but this time we don't recognize the infohash sent by the peer. TEST_F(HandshakeTest, incomingPlaintextUnknownInfoHash) { auto mediator = MediatorMock{ session_ }; mediator.torrents.emplace(TorrentWeAreSeeding.info_hash, TorrentWeAreSeeding); auto [io, sock] = createIncomingIo(session_); sendToClient(sock, PlaintextProtocolName); sendToClient(sock, ReservedBytesNoExtensions); sendToClient(sock, tr_sha1::digest("some other torrent unknown to us"sv)); sendToClient(sock, makeRandomPeerId()); auto const res = runHandshake(&mediator, io); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_FALSE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(io, res->io); EXPECT_FALSE(res->peer_id); EXPECT_EQ(tr_sha1_digest_t{}, io->torrent_hash()); tr_net_close_socket(sock); } TEST_F(HandshakeTest, outgoingPlaintext) { auto const peer_id = makeRandomPeerId(); auto mediator = MediatorMock{ session_ }; mediator.torrents.emplace(UbuntuTorrent.info_hash, TorrentWeAreSeeding); auto [io, sock] = createOutgoingIo(session_, UbuntuTorrent.info_hash); sendToClient(sock, PlaintextProtocolName); sendToClient(sock, ReservedBytesNoExtensions); sendToClient(sock, UbuntuTorrent.info_hash); sendToClient(sock, peer_id); auto const res = runHandshake(&mediator, io); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_TRUE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(io, res->io); EXPECT_TRUE(res->peer_id); EXPECT_EQ(peer_id, res->peer_id); EXPECT_EQ(UbuntuTorrent.info_hash, io->torrent_hash()); EXPECT_EQ(tr_sha1_to_string(UbuntuTorrent.info_hash), tr_sha1_to_string(io->torrent_hash())); tr_net_close_socket(sock); } TEST_F(HandshakeTest, incomingEncrypted) { static auto constexpr ExpectedPeerId = makePeerId("-TR300Z-w4bd4mkebkbi"sv); auto mediator = MediatorMock{ session_ }; mediator.torrents.emplace(UbuntuTorrent.info_hash, UbuntuTorrent); mediator.setPrivateKeyFromBase64("0EYKCwBWQ4Dg9kX3c5xxjVtBDKw="sv); auto [io, sock] = createIncomingIo(session_); // Peer->Client data from a successful encrypted handshake recorded // in the wild for replay here sendB64ToClient( sock, "svkySIFcCsrDTeHjPt516UFbsoR+5vfbe5/m6stE7u5JLZ10kJ19NmP64E10qI" "nn78sCrJgjw1yEHHwrzOcKiRlYvcMotzJMe+SjrFUnaw3KBfn2bcKBhxb/sfM9" "J7nJ"sv); sendB64ToClient( sock, "ICAgICAgICAgIKdr4jIBZ4xFfO4xNiRV7Gl2azTSuTFuu06NU1WyRPif018JYe" "VGwrTPstEPu3V5lmzjtMGVLaL5EErlpJ93Xrz+ea6EIQEUZA+D4jKaV/to9NVi" "04/1W1A2PHgg+I9puac/i9BsFPcjdQeoVtU73lNCbTDQgTieyjDWmwo="sv); auto const res = runHandshake(&mediator, io); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_TRUE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(io, res->io); EXPECT_TRUE(res->peer_id); EXPECT_EQ(ExpectedPeerId, res->peer_id); EXPECT_EQ(UbuntuTorrent.info_hash, io->torrent_hash()); EXPECT_EQ(tr_sha1_to_string(UbuntuTorrent.info_hash), tr_sha1_to_string(io->torrent_hash())); tr_net_close_socket(sock); } // The datastream is identical to HandshakeTest.incomingEncrypted, // but this time we don't recognize the infohash sent by the peer. TEST_F(HandshakeTest, incomingEncryptedUnknownInfoHash) { auto mediator = MediatorMock{ session_ }; mediator.setPrivateKeyFromBase64("0EYKCwBWQ4Dg9kX3c5xxjVtBDKw="sv); auto [io, sock] = createIncomingIo(session_); // Peer->Client data from a successful encrypted handshake recorded // in the wild for replay here sendB64ToClient( sock, "svkySIFcCsrDTeHjPt516UFbsoR+5vfbe5/m6stE7u5JLZ10kJ19NmP64E10qI" "nn78sCrJgjw1yEHHwrzOcKiRlYvcMotzJMe+SjrFUnaw3KBfn2bcKBhxb/sfM9" "J7nJ"sv); sendB64ToClient( sock, "ICAgICAgICAgIKdr4jIBZ4xFfO4xNiRV7Gl2azTSuTFuu06NU1WyRPif018JYe" "VGwrTPstEPu3V5lmzjtMGVLaL5EErlpJ93Xrz+ea6EIQEUZA+D4jKaV/to9NVi" "04/1W1A2PHgg+I9puac/i9BsFPcjdQeoVtU73lNCbTDQgTieyjDWmwo="sv); auto const res = runHandshake(&mediator, io); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_FALSE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(tr_sha1_digest_t{}, io->torrent_hash()); tr_net_close_socket(sock); } TEST_F(HandshakeTest, outgoingEncrypted) { static auto constexpr ExpectedPeerId = makePeerId("-qB4250-scysDI_JuVN3"sv); auto mediator = MediatorMock{ session_ }; mediator.torrents.emplace(UbuntuTorrent.info_hash, UbuntuTorrent); mediator.setPrivateKeyFromBase64("0EYKCwBWQ4Dg9kX3c5xxjVtBDKw="sv); auto [io, sock] = createOutgoingIo(session_, UbuntuTorrent.info_hash); // Peer->Client data from a successful encrypted handshake recorded // in the wild for replay here sendB64ToClient( sock, "Sfgoq/nrQfD4Iwirfk+uhOmQMOC/QwK/vYiOact1NF9TpWXms3cvlKEKxs0VU" "mnmytRh9bh4Lcs1bswlC6R05XrJGzLhZqAqcLUUAR1VTLA5oKSjR1038zFbhn" "c71jqlpney15ChMTnx02Qt+88l0Z9OWLUUJrUVy+OoIaTMSKDDFVOjuj0y+Ii" "cE0ZnN61e0/R/g+APRK5tegw0SLZ3Nr8+y4Dl77sZyc141PR9xvDj0da1eAvf" "BvXyyDem4vUjqiLUNCEV8KDXEMPCPYAQoDZzLvMyOEtJM/if0o0UN88SWtt1k" "jRD8UNvUlXIfM0YsnJhKA6fJ7/4geK7+Wo2aicfaLFOyG5IEJbTg9OQYbDHFa" "oVzD0xY0Dx+J0loqM+CzrPj8UpeXIcbD7pJrT3XPECbFQ12cCY5LW5RymVIx8" "TP0ajGiTxou1L7DbGD54SYgV/4qFbafRsWp9AO+YDJcouFd/jiVN+r3loxvfT" "0A9H9DRAMR0rZKpQpXZ1ZAhAuAOXGHFIvtw8wd6dPybeu5+LoR2S90/IpwHWI" "jbNbypQZuA9hn4JfFMWPP9TG/E11loB4+MkrP22U72ezjL5ipd74AEEP0/u8w" "Gj1t2kXhND9ONfasA+pY25y8GM04M0B7+0xKmsHP7tntwQLAGZATH83rOxaSO" "3+o/RdiKQJAsGxMIU08scBc5VOmrAmjeYrLNpFnpXVuavH5if7490zMCu3DEn" "G9hpbYbiX95T+EUcRbM6pSCvr3Twq1Q="sv); auto const res = runHandshake(&mediator, io, TR_ENCRYPTION_PREFERRED); // check the results EXPECT_TRUE(res.has_value()); assert(res.has_value()); EXPECT_TRUE(res->is_connected); EXPECT_TRUE(res->read_anything_from_peer); EXPECT_EQ(io, res->io); EXPECT_TRUE(res->peer_id); EXPECT_EQ(ExpectedPeerId, res->peer_id); EXPECT_EQ(UbuntuTorrent.info_hash, io->torrent_hash()); EXPECT_EQ(tr_sha1_to_string(UbuntuTorrent.info_hash), tr_sha1_to_string(io->torrent_hash())); tr_net_close_socket(sock); } } // namespace libtransmission::test