fix socks5 issues

Author: arvidn

ChangeLog

@@ -1,5 +1,6 @@
 2.0.13
 
+	* fix socks5 issues
 	* fix issue in loading v2 resume data merkle trees
 
 2.0.12 released

include/libtorrent/proxy_base.hpp

@@ -312,9 +312,10 @@ struct proxy_base
 	{
 		TORRENT_ASSERT(m_magic == 0x1337);
 		if (!e) return false;
-		std::forward<Handler>(h)(e);
 		error_code ec;
-		close(ec);
+		// prevent lifetime management use-after-free
+		close(ec); // close first
+		std::move(h)(e); // consume
 		return true;
 	}
 

include/libtorrent/socks5_stream.hpp

@@ -268,7 +268,7 @@ class socks5_stream : public proxy_base
 		int version = read_uint8(p);
 		int method = read_uint8(p);
 
-		if (version < m_version)
+		if (version != m_version)
 		{
 			std::move(h)(error_code(socks_error::unsupported_version));
 			return;
@@ -378,7 +378,12 @@ class socks5_stream : public proxy_base
 			else
 			{
 				// we either need a hostname or a valid endpoint
-				TORRENT_ASSERT(m_remote_endpoint.address() != address());
+				// MUST prevent malformed buf writes, endpoint corruption
+				if (m_remote_endpoint.address() == address())
+				{
+					std::move(h)(boost::asio::error::invalid_argument);
+					return;
+				}
 
 				write_uint8(aux::is_v4(m_remote_endpoint) ? 1 : 4, p); // address type
 				write_address(m_remote_endpoint.address(), p);
@@ -448,7 +453,7 @@ class socks5_stream : public proxy_base
 
 		if (m_version == 5)
 		{
-			if (version < m_version)
+			if (version != m_version)
 			{
 				std::move(h)(error_code(socks_error::unsupported_version));
 				return;