managerd: Adding a way to retrieve user from stored key

Author: fihuer

Diff for: sshproxy-managerd/sshproxy-managerd.go

@@ -17,6 +17,7 @@ import (
 	"io/ioutil"
 	"net"
 	"os"
+	"regexp"
 	"strings"
 	"time"
 
@@ -203,6 +204,17 @@ func genKey(user, host string) string {
 	return fmt.Sprintf("%s@%s", user, host)
 }
 
+// getUserFromKey returns the user from the key used in the proxiedConnections global variable.
+func getUserFromKey(key string) (string, error) {
+	re := regexp.MustCompile(`^(\w*)@`)
+	match := re.FindStringSubmatch(key)
+	if len(match) < 2 {
+		return "", errors.New("Unable to extract user from given key (" + key + ")")
+	} else {
+		return match[1], nil
+	}
+}
+
 // getAlgorithmAndRoutes returns the selection algorithm and a slice with the
 // possible destinations from the global configuration for a user connected to
 // an hostport and belonging to groups.