rpc: Expose BIP324 session id via getpeerinfo

Author: dhruv

src/net.cpp

@@ -688,6 +688,9 @@ void CNode::CopyStats(CNodeStats& stats)
 
     X(m_conn_type);
     X(m_transport_type);
+    if (m_transport_type == TransportProtocolType::V2) {
+        stats.m_v2_session_id = m_bip324_node_state->session_id;
+    }
 }
 #undef X
 
@@ -713,6 +716,7 @@ void CNode::InitV2P2P(const Span<const std::byte> their_ellswift, const Span<con
     }
     // Both peers must keep around a copy of the garbage terminator for the BIP324 shapable handshake
     m_bip324_node_state->keys_derived = true;
+    m_bip324_node_state->session_id = HexStr(v2_keys.session_id);
 }
 
 void CNode::EnsureInitV2Key(bool initiating)

src/net.h

@@ -234,6 +234,7 @@ class CNodeStats
     uint32_t m_mapped_as;
     ConnectionType m_conn_type;
     TransportProtocolType m_transport_type;
+    std::string m_v2_session_id;
 };
 
 
@@ -469,6 +470,7 @@ struct BIP324NodeState {
     std::array<std::byte, BIP324_GARBAGE_TERMINATOR_LEN> recv_garbage_terminator;
     std::vector<std::byte> garbage_bytes_recd;
     bool keys_derived{false};
+    std::string session_id;
 };
 
 void DeriveBIP324Session(ECDHSecret&& ecdh_secret, BIP324Session& session);

src/rpc/net.cpp

@@ -168,6 +168,7 @@ static RPCHelpMan getpeerinfo()
                                                               "Please note this output is unlikely to be stable in upcoming releases as we iterate to\n"
                                                               "best capture connection behaviors."},
                     {RPCResult::Type::STR, "transport_protocol_type", "Type of transport protocol: \n" + Join(TRANSPORT_TYPE_DOC, ",\n") + ".\n"},
+                    {RPCResult::Type::STR, "v2_session_id", /* optional */ true, "BIP324 session id for an encrypted v2 connection.\n"},
                 }},
             }},
         },
@@ -273,6 +274,9 @@ static RPCHelpMan getpeerinfo()
         obj.pushKV("bytesrecv_per_msg", recvPerMsgType);
         obj.pushKV("connection_type", ConnectionTypeAsString(stats.m_conn_type));
         obj.pushKV("transport_protocol_type", TransportTypeAsString(stats.m_transport_type));
+        if (stats.m_transport_type == TransportProtocolType::V2) {
+            obj.pushKV("v2_session_id", stats.m_v2_session_id);
+        }
 
         ret.push_back(obj);
     }

test/functional/p2p_v2.py

@@ -35,7 +35,12 @@ def run_test(self):
         # sync_all() verifies that the block tips match
         self.sync_all(self.nodes[0:2])
         assert_equal(self.nodes[1].getblockcount(), 5)
-        assert_equal(self.nodes[1].getpeerinfo()[0]["transport_protocol_type"], "v2")
+        peerinfo_0 = self.nodes[0].getpeerinfo()
+        peerinfo_1 = self.nodes[1].getpeerinfo()
+        assert_equal(peerinfo_0[0]["transport_protocol_type"], "v2")
+        assert_equal(peerinfo_1[0]["transport_protocol_type"], "v2")
+        assert_equal(len(peerinfo_0[0]["v2_session_id"]), 64)
+        assert_equal(peerinfo_0[0]["v2_session_id"], peerinfo_1[0]["v2_session_id"])
 
         # V1 nodes can sync with each other
         assert_equal(self.nodes[2].getblockcount(), 0)
@@ -49,7 +54,9 @@ def run_test(self):
         self.sync_all(self.nodes[2:4])
         assert_equal(self.nodes[3].getblockcount(), 8)
         assert self.nodes[0].getbestblockhash() != self.nodes[2].getbestblockhash()
-        assert_equal(self.nodes[2].getpeerinfo()[0]["transport_protocol_type"], "v1")
+        peerinfo_2 = self.nodes[2].getpeerinfo()
+        assert_equal(peerinfo_2[0]["transport_protocol_type"], "v1")
+        assert "v2_session_id" not in peerinfo_2[0]
 
         # V1 nodes can sync with V2 nodes
         self.disconnect_nodes(0, 1)