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, 140 insertions, 0 deletions

diff --git a/src/net/tor_address.h b/src/net/tor_address.h
new file mode 100644
index 000000000..22d8cc119
--- /dev/null
+++ b/src/net/tor_address.h
@@ -0,0 +1,140 @@
+// 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.
+
+#pragma once
+
+#include <boost/utility/string_ref.hpp>
+#include <cstdint>
+#include <string>
+
+#include "common/expect.h"
+#include "net/enums.h"
+#include "net/error.h"
+
+namespace epee
+{
+namespace serialization
+{
+    class portable_storage;
+    struct section;
+}
+}
+
+namespace net
+{
+    //! Tor onion address; internal format not condensed/decoded.
+    class tor_address
+    {
+        std::uint16_t port_;
+        char host_[63]; // null-terminated
+
+        //! Keep in private, `host.size()` has no runtime check
+        tor_address(boost::string_ref host, std::uint16_t port) noexcept;
+
+    public:
+        //! \return Size of internal buffer for host.
+        static constexpr std::size_t buffer_size() noexcept { return sizeof(host_); }
+
+        //! \return `<unknown tor host>`.
+        static const char* unknown_str() noexcept;
+
+        //! An object with `port() == 0` and `host_str() == unknown_str()`.
+        tor_address() noexcept;
+
+        //! \return A default constructed `tor_address` object.
+        static tor_address unknown() noexcept { return tor_address{}; }
+
+        /*!
+            Parse `address` in onion v2 or v3 format with (i.e. x.onion:80)
+            with `default_port` being used iff port is not specified in
+            `address`.
+        */
+        static expect<tor_address> make(boost::string_ref address, std::uint16_t default_port = 0);
+
+        //! Load from epee p2p format, and \return false if not valid tor address
+        bool _load(epee::serialization::portable_storage& src, epee::serialization::section* hparent);
+
+        //! Store in epee p2p format
+        bool store(epee::serialization::portable_storage& dest, epee::serialization::section* hparent) const;
+
+        // Moves and  copies are currently identical
+
+        tor_address(const tor_address& rhs) noexcept;
+        ~tor_address() = default;
+        tor_address& operator=(const tor_address& rhs) noexcept;
+
+        //! \return True if default constructed or via `unknown()`.
+        bool is_unknown() const noexcept;
+
+        bool equal(const tor_address& rhs) const noexcept;
+        bool less(const tor_address& rhs) const noexcept;
+
+        //! \return True if onion addresses are identical.
+        bool is_same_host(const tor_address& rhs) const noexcept;
+
+        //! \return `x.onion` or `x.onion:z` if `port() != 0`.
+        std::string str() const;
+
+        //! \return Null-terminated `x.onion` value or `unknown_str()`.
+        const char* host_str() const noexcept { return host_; }
+
+        //! \return Port value or `0` if unspecified.
+        std::uint16_t port() const noexcept { return port_; }
+
+        static constexpr bool is_loopback() noexcept { return false; }
+        static constexpr bool is_local() noexcept { return false; }
+
+        static constexpr epee::net_utils::address_type get_type_id() noexcept
+        {
+            return epee::net_utils::address_type::tor;
+        }
+
+        static constexpr epee::net_utils::zone get_zone() noexcept
+        {
+            return epee::net_utils::zone::tor;
+        }
+
+        //! \return `!is_unknown()`.
+        bool is_blockable() const noexcept { return !is_unknown(); }
+    };
+
+    inline bool operator==(const tor_address& lhs, const tor_address& rhs) noexcept
+    {
+        return lhs.equal(rhs);
+    }
+
+    inline bool operator!=(const tor_address& lhs, const tor_address& rhs) noexcept
+    {
+        return !lhs.equal(rhs);
+    }
+
+    inline bool operator<(const tor_address& lhs, const tor_address& rhs) noexcept
+    {
+        return lhs.less(rhs);
+    }
+} // net