From 8401b5855faea3d6370ea023f83cb21191c1219c Mon Sep 17 00:00:00 2001
From: Wim <wim@42.be>
Date: Thu, 21 Jul 2016 22:55:31 +0200
Subject: [PATCH] Add SASL (PLAIN) support

---
 irc.go        | 20 +++++++++++++++++++
 irc_struct.go | 24 +++++++++++++----------
 sasl.go       | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 sasl_test.go  | 40 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 128 insertions(+), 10 deletions(-)
 create mode 100644 sasl.go
 create mode 100644 sasl_test.go

diff --git a/irc.go b/irc.go
index 9043e88..0ba1d65 100644
--- a/irc.go
+++ b/irc.go
@@ -439,6 +439,25 @@ func (irc *Connection) Connect(server string) error {
 	if len(irc.Password) > 0 {
 		irc.pwrite <- fmt.Sprintf("PASS %s\r\n", irc.Password)
 	}
+
+	resChan := make(chan *SASLResult)
+	if irc.UseSASL {
+		irc.setupSASLCallbacks(resChan)
+		irc.pwrite <- fmt.Sprintf("CAP LS\r\n")
+		// request SASL
+		irc.pwrite <- fmt.Sprintf("CAP REQ :sasl\r\n")
+		// if sasl request doesn't complete in 15 seconds, close chan and timeout
+		select {
+		case res := <-resChan:
+			if res.Failed {
+				close(resChan)
+				return res.Err
+			}
+		case <-time.After(time.Second * 15):
+			close(resChan)
+			return errors.New("SASL setup timed out. This shouldn't happen.")
+		}
+	}
 	irc.pwrite <- fmt.Sprintf("NICK %s\r\n", irc.nick)
 	irc.pwrite <- fmt.Sprintf("USER %s 0.0.0.0 0.0.0.0 :%s\r\n", irc.user, irc.user)
 	return nil
@@ -466,6 +485,7 @@ func IRC(nick, user string) *Connection {
 		KeepAlive:   4 * time.Minute,
 		Timeout:     1 * time.Minute,
 		PingFreq:    15 * time.Minute,
+		SASLMech:    "PLAIN",
 		QuitMessage: "",
 	}
 	irc.setupCallbacks()
diff --git a/irc_struct.go b/irc_struct.go
index 3e4a438..33db846 100644
--- a/irc_struct.go
+++ b/irc_struct.go
@@ -14,16 +14,20 @@ import (
 
 type Connection struct {
 	sync.WaitGroup
-	Debug     bool
-	Error     chan error
-	Password  string
-	UseTLS    bool
-	TLSConfig *tls.Config
-	Version   string
-	Timeout   time.Duration
-	PingFreq  time.Duration
-	KeepAlive time.Duration
-	Server    string
+	Debug        bool
+	Error        chan error
+	Password     string
+	UseTLS       bool
+	UseSASL      bool
+	SASLLogin    string
+	SASLPassword string
+	SASLMech     string
+	TLSConfig    *tls.Config
+	Version      string
+	Timeout      time.Duration
+	PingFreq     time.Duration
+	KeepAlive    time.Duration
+	Server       string
 
 	socket net.Conn
 	pwrite chan string
diff --git a/sasl.go b/sasl.go
new file mode 100644
index 0000000..e5ff9e3
--- /dev/null
+++ b/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])}
+	})
+}
diff --git a/sasl_test.go b/sasl_test.go
new file mode 100644
index 0000000..27aca18
--- /dev/null
+++ b/sasl_test.go
@@ -0,0 +1,40 @@
+package irc
+
+import (
+	"crypto/tls"
+	"os"
+	"testing"
+	"time"
+)
+
+// set SASLLogin and SASLPassword environment variables before testing
+func TestConnectionSASL(t *testing.T) {
+	SASLServer := "irc.freenode.net:7000"
+	SASLLogin := os.Getenv("SASLLogin")
+	SASLPassword := os.Getenv("SASLPassword")
+
+	if SASLLogin == "" {
+		t.SkipNow()
+	}
+	irccon := IRC("go-eventirc", "go-eventirc")
+	irccon.VerboseCallbackHandler = true
+	irccon.Debug = true
+	irccon.UseTLS = true
+	irccon.UseSASL = true
+	irccon.SASLLogin = SASLLogin
+	irccon.SASLPassword = SASLPassword
+	irccon.TLSConfig = &tls.Config{InsecureSkipVerify: true}
+	irccon.AddCallback("001", func(e *Event) { irccon.Join("#go-eventirc") })
+
+	irccon.AddCallback("366", func(e *Event) {
+		irccon.Privmsg("#go-eventirc", "Test Message SASL\n")
+		time.Sleep(2 * time.Second)
+		irccon.Quit()
+	})
+
+	err := irccon.Connect(SASLServer)
+	if err != nil {
+		t.Fatal("SASL failed")
+	}
+	irccon.Loop()
+}