epee: add SSL support

RPC connections now have optional tranparent SSL.

An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.

SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.

Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.

To generate long term certificates:

openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT

/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.

SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.

1 files changed, 127 insertions, 72 deletions

diff --git a/contrib/epee/include/net/net_helper.h b/contrib/epee/include/net/net_helper.h
index 94744ac21..5d9bb61cf 100644
--- a/contrib/epee/include/net/net_helper.h
+++ b/contrib/epee/include/net/net_helper.h
@@ -40,6 +40,7 @@
 #include <boost/lambda/lambda.hpp>
 #include <boost/interprocess/detail/atomic.hpp>
 #include "net/net_utils_base.h"
+#include "net/net_ssl.h"
 #include "misc_language.h"
 
 #undef MONERO_DEFAULT_LOG_CATEGORY
@@ -57,6 +58,13 @@ namespace net_utils
 
   class blocked_mode_client
 	{
+		enum try_connect_result_t
+		{
+			CONNECT_SUCCESS,
+			CONNECT_FAILURE,
+			CONNECT_NO_SSL,
+		};
+
 		
 		
 				struct handler_obj
@@ -84,9 +92,9 @@ namespace net_utils
                             m_connected(false), 
                             m_deadline(m_io_service), 
                             m_shutdowned(0),
-                            m_ssl(false),
-                            m_ctx(boost::asio::ssl::context::sslv23),
-                            m_ssl_socket(m_io_service,m_ctx)
+                            m_ssl_support(epee::net_utils::ssl_support_t::e_ssl_support_autodetect),
+                            m_ctx({boost::asio::ssl::context(boost::asio::ssl::context::sslv23), {}}),
+                            m_ssl_socket(new boost::asio::ssl::stream<boost::asio::ip::tcp::socket>(m_io_service,m_ctx.context))
 		{
 			
 			
@@ -110,28 +118,92 @@ namespace net_utils
 			catch(...) { /* ignore */ }
 		}
 
+		inline void set_ssl(epee::net_utils::ssl_support_t ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_autodetect, const std::pair<std::string, std::string> &private_key_and_certificate_path = {}, const std::list<std::string> &allowed_certificates = std::list<std::string>(), bool allow_any_cert = false)
+		{
+			if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_disabled)
+				m_ctx = {boost::asio::ssl::context(boost::asio::ssl::context::sslv23), {}};
+			else
+				m_ctx = create_ssl_context(private_key_and_certificate_path, allowed_certificates, allow_any_cert);
+			m_ssl_support = ssl_support;
+		}
+
     inline
-      bool connect(const std::string& addr, int port, std::chrono::milliseconds timeout, bool ssl = false, const std::string& bind_ip = "0.0.0.0")
+      bool connect(const std::string& addr, int port, std::chrono::milliseconds timeout, const std::string& bind_ip = "0.0.0.0")
     {
-      return connect(addr, std::to_string(port), timeout, ssl, bind_ip);
+      return connect(addr, std::to_string(port), timeout, bind_ip);
     }
 
     inline
-			bool connect(const std::string& addr, const std::string& port, std::chrono::milliseconds timeout, bool ssl = false, const std::string& bind_ip = "0.0.0.0")
+			try_connect_result_t try_connect(const std::string& addr, const std::string& port, const boost::asio::ip::tcp::endpoint &remote_endpoint, std::chrono::milliseconds timeout, const std::string& bind_ip, epee::net_utils::ssl_support_t ssl_support)
 		{
-      m_connected = false;
-      m_ssl = ssl;
+				m_ssl_socket->next_layer().open(remote_endpoint.protocol());
+				if(bind_ip != "0.0.0.0" && bind_ip != "0" && bind_ip != "" )
+				{
+					boost::asio::ip::tcp::endpoint local_endpoint(boost::asio::ip::address::from_string(addr.c_str()), 0);
+					m_ssl_socket->next_layer().bind(local_endpoint);
+				}
+
+				
+				m_deadline.expires_from_now(timeout);
+
+				boost::system::error_code ec = boost::asio::error::would_block;
+
+				m_ssl_socket->next_layer().async_connect(remote_endpoint, boost::lambda::var(ec) = boost::lambda::_1);
+				while (ec == boost::asio::error::would_block)
+				{	
+					m_io_service.run_one(); 
+				}
+				
+				if (!ec && m_ssl_socket->next_layer().is_open())
+				{
+					m_connected = true;
+					m_deadline.expires_at(std::chrono::steady_clock::time_point::max());
+					// SSL Options
+					if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled || ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
+					{
+						if (!ssl_handshake(*m_ssl_socket, boost::asio::ssl::stream_base::client, m_ctx))
+						{
+							if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
+							{
+								boost::system::error_code ignored_ec;
+								m_ssl_socket->next_layer().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);
+								m_ssl_socket->next_layer().close();
+								m_connected = false;
+								return CONNECT_NO_SSL;
+							}
+							else
+							{
+								MWARNING("Failed to establish SSL connection");
+								m_connected = false;
+								return CONNECT_FAILURE;
+							}
+						}
+						m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_enabled;
+					}
+					return CONNECT_SUCCESS;
+				}else
+				{
+					MWARNING("Some problems at connect, message: " << ec.message());
+					return CONNECT_FAILURE;
+				}
+
+		}
+
+    inline
+			bool connect(const std::string& addr, const std::string& port, std::chrono::milliseconds timeout, const std::string& bind_ip = "0.0.0.0")
+		{
+			m_connected = false;
 			try
 			{
-				m_ssl_socket.next_layer().close();
+				m_ssl_socket->next_layer().close();
 
 				// Set SSL options
 				// disable sslv2
-				m_ctx.set_options(boost::asio::ssl::context::default_workarounds | boost::asio::ssl::context::no_sslv2);
-				m_ctx.set_default_verify_paths();
+				m_ctx.context.set_options(boost::asio::ssl::context::default_workarounds | boost::asio::ssl::context::no_sslv2);
+				m_ctx.context.set_default_verify_paths();
+				m_ssl_socket.reset(new boost::asio::ssl::stream<boost::asio::ip::tcp::socket>(m_io_service, m_ctx.context));
 
 				// Get a list of endpoints corresponding to the server name.
-				
 
 				//////////////////////////////////////////////////////////////////////////
 
@@ -151,45 +223,20 @@ namespace net_utils
 				//boost::asio::ip::tcp::endpoint remote_endpoint(boost::asio::ip::address::from_string(addr.c_str()), port);
 				boost::asio::ip::tcp::endpoint remote_endpoint(*iterator);
 
-
-				m_ssl_socket.next_layer().open(remote_endpoint.protocol());
-				if(bind_ip != "0.0.0.0" && bind_ip != "0" && bind_ip != "" )
-				{
-					boost::asio::ip::tcp::endpoint local_endpoint(boost::asio::ip::address::from_string(addr.c_str()), 0);
-					m_ssl_socket.next_layer().bind(local_endpoint);
-				}
-
-				
-				m_deadline.expires_from_now(timeout);
-
-
-				boost::system::error_code ec = boost::asio::error::would_block;
-
-				m_ssl_socket.next_layer().async_connect(remote_endpoint, boost::lambda::var(ec) = boost::lambda::_1);
-				while (ec == boost::asio::error::would_block)
-				{	
-					m_io_service.run_one(); 
-				}
-				
-				if (!ec && m_ssl_socket.next_layer().is_open())
+				try_connect_result_t try_connect_result = try_connect(addr, port, remote_endpoint, timeout, bind_ip, m_ssl_support);
+				if (try_connect_result == CONNECT_FAILURE)
+					return false;
+				if (m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
 				{
-					m_connected = true;
-					m_deadline.expires_at(std::chrono::steady_clock::time_point::max());
-					// SSL Options
-					if(m_ssl) {
-						// Disable verification of host certificate
-						m_ssl_socket.set_verify_mode(boost::asio::ssl::verify_peer);
-						// Handshake
-						m_ssl_socket.next_layer().set_option(boost::asio::ip::tcp::no_delay(true));
-						m_ssl_socket.handshake(boost::asio::ssl::stream_base::client);
+					m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_enabled;
+					if (try_connect_result == CONNECT_NO_SSL)
+					{
+						MERROR("SSL handshake failed on an autodetect connection, reconnecting without SSL");
+						m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_disabled;
+						if (try_connect(addr, port, remote_endpoint, timeout, bind_ip, m_ssl_support) != CONNECT_SUCCESS)
+							return false;
 					}
-					return true;
-				}else
-				{
-					MWARNING("Some problems at connect, message: " << ec.message());
-					return false;
 				}
-
 			}
 			catch(const boost::system::system_error& er)
 			{
@@ -213,9 +260,9 @@ namespace net_utils
 				if(m_connected)
 				{
 					m_connected = false;
-					if(m_ssl)
+					if(m_ssl_support != epee::net_utils::ssl_support_t::e_ssl_support_disabled)
 						shutdown_ssl();
-					m_ssl_socket.next_layer().shutdown(boost::asio::ip::tcp::socket::shutdown_both);
+					m_ssl_socket->next_layer().shutdown(boost::asio::ip::tcp::socket::shutdown_both);
 				}
 			}
 			
@@ -342,9 +389,13 @@ namespace net_utils
 			return true;
 		}
 
-		bool is_connected()
+		bool is_connected(bool *ssl = NULL)
 		{
-			return m_connected && m_ssl_socket.next_layer().is_open();
+			if (!m_connected || !m_ssl_socket->next_layer().is_open())
+				return false;
+			if (ssl)
+				*ssl = m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled;
+			return true;
 		}
 
 		inline 
@@ -506,15 +557,15 @@ namespace net_utils
 		{
 			m_deadline.cancel();
 			boost::system::error_code ec;
-			if(m_ssl)
+			if(m_ssl_support != epee::net_utils::ssl_support_t::e_ssl_support_disabled)
 				shutdown_ssl();
-			m_ssl_socket.next_layer().cancel(ec);
+			m_ssl_socket->next_layer().cancel(ec);
 			if(ec)
 				MDEBUG("Problems at cancel: " << ec.message());
-			m_ssl_socket.next_layer().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
+			m_ssl_socket->next_layer().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
 			if(ec)
 				MDEBUG("Problems at shutdown: " << ec.message());
-			m_ssl_socket.next_layer().close(ec);
+			m_ssl_socket->next_layer().close(ec);
 			if(ec)
 				MDEBUG("Problems at close: " << ec.message());
 			boost::interprocess::ipcdetail::atomic_write32(&m_shutdowned, 1);
@@ -533,7 +584,7 @@ namespace net_utils
 
 		boost::asio::ip::tcp::socket& get_socket()
 		{
-			return m_ssl_socket.next_layer();
+			return m_ssl_socket->next_layer();
 		}
 		
 	private:
@@ -550,7 +601,7 @@ namespace net_utils
 				// connect(), read_line() or write_line() functions to return.
 				LOG_PRINT_L3("Timed out socket");
         m_connected = false;
-				m_ssl_socket.next_layer().close();
+				m_ssl_socket->next_layer().close();
 
 				// There is no longer an active deadline. The expiry is set to positive
 				// infinity so that the actor takes no action until a new deadline is set.
@@ -565,7 +616,7 @@ namespace net_utils
 			// ssl socket shutdown blocks if server doesn't respond. We close after 2 secs
 			boost::system::error_code ec = boost::asio::error::would_block;
 			m_deadline.expires_from_now(std::chrono::milliseconds(2000));
-			m_ssl_socket.async_shutdown(boost::lambda::var(ec) = boost::lambda::_1);
+			m_ssl_socket->async_shutdown(boost::lambda::var(ec) = boost::lambda::_1);
 			while (ec == boost::asio::error::would_block)
 			{
 				m_io_service.run_one();
@@ -586,35 +637,39 @@ namespace net_utils
 		bool write(const void* data, size_t sz, boost::system::error_code& ec)
 		{
 			bool success;
-			if(m_ssl)
-				success = boost::asio::write(m_ssl_socket, boost::asio::buffer(data, sz), ec);
+			if(m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled)
+				success = boost::asio::write(*m_ssl_socket, boost::asio::buffer(data, sz), ec);
 			else
-				success = boost::asio::write(m_ssl_socket.next_layer(), boost::asio::buffer(data, sz), ec);
+				success = boost::asio::write(m_ssl_socket->next_layer(), boost::asio::buffer(data, sz), ec);
 			return success;
 		}
 		
 		void async_write(const void* data, size_t sz, boost::system::error_code& ec) 
 		{
-			if(m_ssl)
-				boost::asio::async_write(m_ssl_socket, boost::asio::buffer(data, sz), boost::lambda::var(ec) = boost::lambda::_1);
+			if(m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled)
+				boost::asio::async_write(*m_ssl_socket, boost::asio::buffer(data, sz), boost::lambda::var(ec) = boost::lambda::_1);
 			else
-				boost::asio::async_write(m_ssl_socket.next_layer(), boost::asio::buffer(data, sz), boost::lambda::var(ec) = boost::lambda::_1);
+				boost::asio::async_write(m_ssl_socket->next_layer(), boost::asio::buffer(data, sz), boost::lambda::var(ec) = boost::lambda::_1);
 		}
 		
 		void async_read(char* buff, size_t sz, boost::asio::detail::transfer_at_least_t transfer_at_least, handler_obj& hndlr)
 		{
-			if(!m_ssl)
-				boost::asio::async_read(m_ssl_socket.next_layer(), boost::asio::buffer(buff, sz), transfer_at_least, hndlr);
+			if(m_ssl_support != epee::net_utils::ssl_support_t::e_ssl_support_enabled)
+				boost::asio::async_read(m_ssl_socket->next_layer(), boost::asio::buffer(buff, sz), transfer_at_least, hndlr);
 			else
-				boost::asio::async_read(m_ssl_socket, boost::asio::buffer(buff, sz), transfer_at_least, hndlr);
+				boost::asio::async_read(*m_ssl_socket, boost::asio::buffer(buff, sz), transfer_at_least, hndlr);
 			
 		}
 		
 	protected:
 		boost::asio::io_service m_io_service;
-		boost::asio::ssl::context m_ctx;
-		boost::asio::ssl::stream<boost::asio::ip::tcp::socket> m_ssl_socket;
-		bool m_ssl;
+		epee::net_utils::ssl_context_t m_ctx;
+		std::shared_ptr<boost::asio::ssl::stream<boost::asio::ip::tcp::socket>> m_ssl_socket;
+		epee::net_utils::ssl_support_t m_ssl_support;
+		std::string m_ssl_private_key;
+		std::string m_ssl_certificate;
+		std::list<std::string> m_ssl_allowed_certificates;
+		bool m_ssl_allow_any_cerl;
 		bool m_initialized;
 		bool m_connected;
 		boost::asio::steady_timer m_deadline;
@@ -722,7 +777,7 @@ namespace net_utils
 				// asynchronous operations are cancelled. This allows the blocked
 				// connect(), read_line() or write_line() functions to return.
 				LOG_PRINT_L3("Timed out socket");
-				m_ssl_socket.next_layer().close();
+				m_ssl_socket->next_layer().close();
 
 				// There is no longer an active deadline. The expiry is set to positive
 				// infinity so that the actor takes no action until a new deadline is set.