Fix password changing getting stuck if wrong password is entered once

src/clientiface.cpp

@@ -596,6 +596,15 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 	}
 }
 
+void RemoteClient::resetChosenMech()
+{
+	if (chosen_mech == AUTH_MECHANISM_SRP) {
+		srp_verifier_delete((SRPVerifier *) auth_data);
+		auth_data = nullptr;
+	}
+	chosen_mech = AUTH_MECHANISM_NONE;
+}
+
 u64 RemoteClient::uptime() const
 {
 	return porting::getTimeS() - m_connection_time;

src/clientiface.h

@@ -243,6 +243,8 @@ public:
 	u32 allowed_auth_mechs = 0;
 	u32 allowed_sudo_mechs = 0;
 
+	void resetChosenMech();
+
 	bool isSudoMechAllowed(AuthMechanism mech)
 	{ return allowed_sudo_mechs & mech; }
 	bool isMechAllowed(AuthMechanism mech)

src/network/serverpackethandler.cpp

@@ -1639,6 +1639,7 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 			<< std::endl;
 		if (wantSudo) {
 			DenySudoAccess(peer_id);
+			client->resetChosenMech();
 			return;
 		}
 
@@ -1705,6 +1706,7 @@ void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
 				<< " tried to change their password, but supplied wrong"
 				<< " (SRP) password for authentication." << std::endl;
 			DenySudoAccess(peer_id);
+			client->resetChosenMech();
 			return;
 		}