Actually add sasl.go

vendor/github.com/thoj/go-ircevent/sasl.go

@@ -0,0 +1,54 @@
+package irc
+
+import (
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type SASLResult struct {
+	Failed bool
+	Err    error
+}
+
+func (irc *Connection) setupSASLCallbacks(result chan<- *SASLResult) {
+	irc.AddCallback("CAP", func(e *Event) {
+		if len(e.Arguments) == 3 {
+			if e.Arguments[1] == "LS" {
+				if !strings.Contains(e.Arguments[2], "sasl") {
+					result <- &SASLResult{true, errors.New("no SASL capability " + e.Arguments[2])}
+				}
+			}
+			if e.Arguments[1] == "ACK" {
+				if irc.SASLMech != "PLAIN" {
+					result <- &SASLResult{true, errors.New("only PLAIN is supported")}
+				}
+				irc.SendRaw("AUTHENTICATE " + irc.SASLMech)
+			}
+		}
+	})
+	irc.AddCallback("AUTHENTICATE", func(e *Event) {
+		str := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s\x00%s\x00%s", irc.SASLLogin, irc.SASLLogin, irc.SASLPassword)))
+		irc.SendRaw("AUTHENTICATE " + str)
+	})
+	irc.AddCallback("901", func(e *Event) {
+		irc.SendRaw("CAP END")
+		irc.SendRaw("QUIT")
+		result <- &SASLResult{true, errors.New(e.Arguments[1])}
+	})
+	irc.AddCallback("902", func(e *Event) {
+		irc.SendRaw("CAP END")
+		irc.SendRaw("QUIT")
+		result <- &SASLResult{true, errors.New(e.Arguments[1])}
+	})
+	irc.AddCallback("903", func(e *Event) {
+		irc.SendRaw("CAP END")
+		result <- &SASLResult{false, nil}
+	})
+	irc.AddCallback("904", func(e *Event) {
+		irc.SendRaw("CAP END")
+		irc.SendRaw("QUIT")
+		result <- &SASLResult{true, errors.New(e.Arguments[1])}
+	})
+}