Scaffold security

libp2p/security/secure_conn_interface.py

@@ -0,0 +1,21 @@
+from abc import ABC, abstractmethod
+
+"""
+Represents a secured connection object, which includes a connection and details about the security
+involved in the secured connection
+
+Relevant go repo: https://github.com/libp2p/go-conn-security/blob/master/interface.go
+"""
+class ISecureConn(ABC):
+
+    @abstractmethod
+    def get_conn(self):
+        """
+        :return: connection object that has been made secure
+        """
+
+    def get_security_details(self):
+        """
+        :return: map containing details about the connections security
+        """
+

libp2p/security/secure_transport_interface.py

@@ -0,0 +1,27 @@
+import asyncio
+
+from abc import ABC, abstractmethod
+
+"""
+Transport that is used to secure a connection. This transport is 
+chosen by a security transport multistream module.
+
+Relevant go repo: https://github.com/libp2p/go-conn-security/blob/master/interface.go
+"""
+class ISecureTransport(ABC):
+
+    @abstractmethod
+    async def secure_inbound(self, conn):
+        """
+        Secure the connection, either locally or by communicating with opposing node via conn,
+        for an inbound connection (i.e. we are not the initiator)
+        :return: secure connection object (that implements secure_conn_interface)
+        """
+
+    @abstractmethod
+    async def secure_outbound(self, conn, peer_id):
+        """
+        Secure the connection, either locally or by communicating with opposing node via conn,
+        for an inbound connection (i.e. we are the initiator)
+        :return: secure connection object (that implements secure_conn_interface)
+        """

libp2p/security/security_multistream.py

@@ -0,0 +1,87 @@
+import asyncio
+
+from abc import ABC, abstractmethod
+from libp2p.protocol_muxer.multiselect_client import MultiselectClient
+from libp2p.protocol_muxer.multiselect import Multiselect
+
+"""
+Represents a secured connection object, which includes a connection and details about the security
+involved in the secured connection
+
+Relevant go repo: https://github.com/libp2p/go-conn-security/blob/master/interface.go
+"""
+class SecurityMultistream(ABC):
+
+    def __init__():
+        # Map protocol to secure transport 
+        self.transports = {}
+
+        # Create multiselect
+        self.multiselect = Multiselect()
+
+        # Create multiselect client
+        self.multiselect_client = MultiselectClient()
+
+    def add_transport(self, protocol, transport):
+        # Associate protocol with transport
+        self.transports[protocol] = transport
+
+        # Add protocol and handler to multiselect
+        # Note: None is added as the handler for the given protocol since
+        # we only care about selecting the protocol, not any handler function
+        self.multiselect.add_handler(protocol, None)
+
+    
+    async def secure_inbound(self, conn):
+        """
+        Secure the connection, either locally or by communicating with opposing node via conn,
+        for an inbound connection (i.e. we are not the initiator)
+        :return: secure connection object (that implements secure_conn_interface)
+        """
+
+        # Select a secure transport
+        transport = await self.select_transport(conn, True)
+
+        # Create secured connection
+        secure_conn = await transport.secure_inbound(conn)
+
+        return secure_conn
+
+
+    async def secure_outbound(self, conn, peer_id):
+        """
+        Secure the connection, either locally or by communicating with opposing node via conn,
+        for an inbound connection (i.e. we are the initiator)
+        :return: secure connection object (that implements secure_conn_interface)
+        """
+
+        # Select a secure transport
+        transport = await self.select_transport(conn, True)
+
+        # Create secured connection
+        secure_conn = await transport.secure_outbound(conn, peer_id)
+
+        return secure_conn
+
+
+    async def select_transport(self, conn, initiator):
+        """
+        Select a transport that both us and the node on the 
+        other end of conn support and agree on
+        :param conn: conn to choose a transport over
+        :param initiator: true if we are the initiator, false otherwise
+        :return: selected secure transport
+        """
+        # TODO: Is conn acceptable to multiselect/multiselect_client instead of stream? In go repo,
+        # they pass in a raw conn (https://raw.githubusercontent.com/libp2p/go-conn-security-multistream/master/ssms.go)
+        
+        protocol = None
+        if initiator:
+            # Select protocol if initiator
+            protocol = await self.multiselect_client.select_one_of(list(self.transports.keys()), conn)
+        else:
+            # Select protocol if non-initiator
+            protocol = await self.multiselect.negotiate(conn)
+
+        # Return transport from protocol
+        return self.transports[protocol]