Move SASL mechanism detection to xmpp/sasl.go

1 files changed, 30 insertions, 0 deletions

diff --git a/xmpp/sasl.go b/xmpp/sasl.go
index 8687782..e06bcd5 100644
--- a/xmpp/sasl.go
+++ b/xmpp/sasl.go
@@ -34,3 +34,33 @@ func (s *session) sasl() {
 		}
 	}
 }
+
+// hasSaslPlain scans the given stream features XML element for the SASL PLAIN
+// mechanism which is supported by xengineering.eu/limox/xmpp. It returns true
+// if the stream has support for this mechanism and false otherwise.
+func hasSaslPlain(e []xml.Token) bool {
+	mechanism := xml.Name{`urn:ietf:params:xml:ns:xmpp-sasl`, `mechanism`}
+
+	for i, t := range e {
+		switch s := t.(type) {
+		case xml.StartElement:
+			if s.Name == mechanism {
+				if i+1 < len(e) {
+					subtype := func() string {
+						switch c := e[i+1].(type) {
+						case xml.CharData:
+							return string(c)
+						default:
+							return ""
+						}
+					}()
+					if subtype == `PLAIN` {
+						return true
+					}
+				}
+			}
+		}
+	}
+
+	return false
+}