Adding initial support for broadcasting transactions over Tor

  - Support for ".onion" in --add-exclusive-node and --add-peer
  - Add --anonymizing-proxy for outbound Tor connections
  - Add --anonymous-inbounds for inbound Tor connections
  - Support for sharing ".onion" addresses over Tor connections
  - Support for broadcasting transactions received over RPC exclusively
    over Tor (else broadcast over public IP when Tor not enabled).

1 files changed, 203 insertions, 0 deletions

diff --git a/src/net/tor_address.cpp b/src/net/tor_address.cpp
new file mode 100644
index 000000000..904a9a0fc
--- /dev/null
+++ b/src/net/tor_address.cpp
@@ -0,0 +1,203 @@
+// Copyright (c) 2018, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. 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.
+//
+// 3. Neither the name of the copyright holder 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 HOLDER 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.
+
+#include "tor_address.h"
+
+#include <algorithm>
+#include <boost/spirit/include/karma_generate.hpp>
+#include <boost/spirit/include/karma_uint.hpp>
+#include <cassert>
+#include <cstring>
+#include <limits>
+
+#include "net/error.h"
+#include "serialization/keyvalue_serialization.h"
+#include "storages/portable_storage.h"
+#include "string_tools.h"
+
+namespace net
+{
+    namespace
+    {
+        constexpr const char tld[] = u8".onion";
+        constexpr const char unknown_host[] = "<unknown tor host>";
+
+        constexpr const unsigned v2_length = 16;
+        constexpr const unsigned v3_length = 56;
+
+        constexpr const char base32_alphabet[] =
+            u8"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz234567";
+
+        expect<void> host_check(boost::string_ref host) noexcept
+        {
+            if (!host.ends_with(tld))
+                return {net::error::expected_tld};
+
+            host.remove_suffix(sizeof(tld) - 1);
+
+            //! \TODO v3 has checksum, base32 decoding is required to verify it
+            if (host.size() != v2_length && host.size() != v3_length)
+                return {net::error::invalid_tor_address};
+            if (host.find_first_not_of(base32_alphabet) != boost::string_ref::npos)
+                return {net::error::invalid_tor_address};
+
+            return success();
+        }
+
+        struct tor_serialized
+        {
+            std::string host;
+            std::uint16_t port;
+
+            BEGIN_KV_SERIALIZE_MAP()
+                KV_SERIALIZE(host)
+                KV_SERIALIZE(port)
+            END_KV_SERIALIZE_MAP()
+        };
+    }
+
+    tor_address::tor_address(const boost::string_ref host, const std::uint16_t port) noexcept
+      : port_(port)
+    {
+        // this is a private constructor, throw if moved to public
+        assert(host.size() < sizeof(host_));
+
+        const std::size_t length = std::min(sizeof(host_) - 1, host.size());
+        std::memcpy(host_, host.data(), length);
+        std::memset(host_ + length, 0, sizeof(host_) - length);
+    }
+
+    const char* tor_address::unknown_str() noexcept
+    {
+        return unknown_host;
+    }
+
+    tor_address::tor_address() noexcept
+      : port_(0)
+    {
+        static_assert(sizeof(unknown_host) <= sizeof(host_), "bad buffer size");
+        std::memcpy(host_, unknown_host, sizeof(unknown_host));
+        std::memset(host_ + sizeof(unknown_host), 0, sizeof(host_) - sizeof(unknown_host));
+    }
+
+    expect<tor_address> tor_address::make(const boost::string_ref address, const std::uint16_t default_port)
+    {
+        boost::string_ref host = address.substr(0, address.rfind(':'));
+        const boost::string_ref port =
+            address.substr(host.size() + (host.size() == address.size() ? 0 : 1));
+
+        MONERO_CHECK(host_check(host));
+
+        std::uint16_t porti = default_port;
+        if (!port.empty() && !epee::string_tools::get_xtype_from_string(porti, std::string{port}))
+            return {net::error::invalid_port};
+
+        static_assert(v2_length <= v3_length, "bad internal host size");
+        static_assert(v3_length + sizeof(tld) == sizeof(tor_address::host_), "bad internal host size");
+        return tor_address{host, porti};
+    }
+
+    bool tor_address::_load(epee::serialization::portable_storage& src, epee::serialization::section* hparent)
+    {
+        tor_serialized in{};
+        if (in._load(src, hparent) && in.host.size() < sizeof(host_) && (in.host == unknown_host || !host_check(in.host).has_error()))
+        {
+            std::memcpy(host_, in.host.data(), in.host.size());
+            std::memset(host_ + in.host.size(), 0, sizeof(host_) - in.host.size());
+            port_ = in.port;
+            return true;
+        }
+        static_assert(sizeof(unknown_host) <= sizeof(host_), "bad buffer size");
+        std::memcpy(host_, unknown_host, sizeof(unknown_host)); // include null terminator
+        port_ = 0;
+        return false;
+    }
+
+    bool tor_address::store(epee::serialization::portable_storage& dest, epee::serialization::section* hparent) const
+    {
+        const tor_serialized out{std::string{host_}, port_};
+        return out.store(dest, hparent);
+    }
+
+    tor_address::tor_address(const tor_address& rhs) noexcept
+      : port_(rhs.port_)
+    {
+        std::memcpy(host_, rhs.host_, sizeof(host_));
+    }
+
+    tor_address& tor_address::operator=(const tor_address& rhs) noexcept
+    {
+        if (this != std::addressof(rhs))
+        {
+            port_ = rhs.port_;
+            std::memcpy(host_, rhs.host_, sizeof(host_));
+        }
+        return *this;
+    }
+
+    bool tor_address::is_unknown() const noexcept
+    {
+        static_assert(1 <= sizeof(host_), "host size too small");
+        return host_[0] == '<'; // character is not allowed otherwise
+    }
+
+    bool tor_address::equal(const tor_address& rhs) const noexcept
+    {
+        return port_ == rhs.port_ && is_same_host(rhs);
+    }
+
+    bool tor_address::less(const tor_address& rhs) const noexcept
+    {
+        return std::strcmp(host_str(), rhs.host_str()) < 0 || port() < rhs.port();
+    }
+
+    bool tor_address::is_same_host(const tor_address& rhs) const noexcept
+    {
+        //! \TODO v2 and v3 should be comparable - requires base32
+        return std::strcmp(host_str(), rhs.host_str()) == 0;
+    }
+
+    std::string tor_address::str() const
+    {
+        const std::size_t host_length = std::strlen(host_str());
+        const std::size_t port_length =
+            port_ == 0 ? 0 : std::numeric_limits<std::uint16_t>::digits10 + 2;
+
+        std::string out{};
+        out.reserve(host_length + port_length);
+        out.assign(host_str(), host_length);
+
+        if (port_ != 0)
+        {
+            out.push_back(':');
+            namespace karma = boost::spirit::karma;
+            karma::generate(std::back_inserter(out), karma::ushort_, port());
+        }
+        return out;
+    }
+}