[Bugfix] fix telnet login regex panic err

pkg/proxy/proxy.go

@@ -116,7 +116,10 @@ func (p *ProxyServer) getSSHConn() (srvConn *srvconn.ServerSSHConnection, err er
 func (p *ProxyServer) getTelnetConn() (srvConn *srvconn.ServerTelnetConnection, err error) {
 	conf := config.GetConf()
 	cusString := conf.TelnetRegex
-	pattern, _ := regexp.Compile(cusString)
+	pattern, err := regexp.Compile(cusString)
+	if err != nil {
+		logger.Errorf("telnet custom regex %s compile err: %s", cusString, err)
+	}
 	srvConn = &srvconn.ServerTelnetConnection{
 		User:                 p.User,
 		Asset:                p.Asset,

pkg/srvconn/telnetconn.go

@@ -132,7 +132,7 @@ func (tc *ServerTelnetConnection) login(data []byte) AuthStatus {
 		return AuthSuccess
 	}
 	if tc.CustomString != "" {
-		if tc.CustomSuccessPattern.Match(data) {
+		if tc.CustomSuccessPattern != nil && tc.CustomSuccessPattern.Match(data) {
 			return AuthSuccess
 		}
 	}