1 files changed, 86 insertions, 0 deletions
diff --git a/cap_sasl.go b/cap_sasl.go
new file mode 100644
index 0000000..7044efb
--- /dev/null
+++ b/cap_sasl.go
@@ -0,0 +1,86 @@
+package main
+
+import (
+	"encoding/base64"
+	"bytes"
+)
+
+type ExtraSasl struct {
+	AuthMethod string
+}
+
+const (
+	RPL_LOGGEDIN    = "900"
+	RPL_LOGGEDOUT   = "901"
+	ERR_NICKLOCKED  = "902"
+	RPL_SASLSUCCESS = "903"
+	ERR_SASLFAIL    = "904"
+	ERR_SASLTOOLONG = "905"
+	ERR_SASLABORTED = "906"
+	ERR_SASLALREADY = "907"
+	RPL_SASLMECHS   = "908"
+)
+
+const (
+	panicSaslMethod = "stored illegal SASL method"
+)
+
+func init() {
+	Caps["sasl"] = "PLAIN,EXTERNAL"
+	CommandHandlers["AUTHENTICATE"] = handleClientAuthenticate
+}
+
+func handleClientAuthenticate(msg RMsg, client *Client) error {
+	_, ok := client.Caps["sasl"]
+	if !ok {
+		return client.Send(MakeMsg(self, "TODO", "you're trying to sasl without requesting for it"))
+	}
+
+	if len(msg.Params) < 1 {
+		return client.Send(MakeMsg(self, ERR_NEEDMOREPARAMS, "AUTHENTICATE", "Not enough parameters"))
+	}
+
+	extraSasl_, ok := client.Extra["sasl"]
+	if !ok {
+		client.Extra["sasl"] = &ExtraSasl{}
+		extraSasl_ = client.Extra["sasl"]
+	}
+	extraSasl, ok := extraSasl_.(*ExtraSasl)
+	if !ok {
+		panic(panicType)
+	}
+
+	switch extraSasl.AuthMethod {
+	case "":
+		if msg.Params[0] != "PLAIN" && msg.Params[0] != "EXTERNAL" {
+			return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed (invalid method)"))
+		}
+		extraSasl.AuthMethod = msg.Params[0]
+		return client.Send(MakeMsg(self, "AUTHENTICATE", "+"))
+	case "*": // Abort
+		extraSasl.AuthMethod = ""
+		return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed (aborted)"))
+	case "EXTERNAL":
+		extraSasl.AuthMethod = ""
+		return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed"))
+	case "PLAIN":
+		extraSasl.AuthMethod = ""
+		saslPlainData, err := base64.StdEncoding.DecodeString(msg.Params[0])
+		if err != nil {
+			return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed (base64 decoding error)"))
+		}
+		saslPlainSegments := bytes.Split(saslPlainData, []byte{0})
+		if len(saslPlainSegments) != 3 {
+			return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed (not three segments)"))
+		}
+		_ = string(saslPlainSegments[0]) // authzid unused
+		authcid := string(saslPlainSegments[1])
+		passwd := string(saslPlainSegments[2])
+		if authcid == "runxiyu" && passwd == "hunter2" {
+			return client.Send(MakeMsg(self, RPL_SASLSUCCESS, client.Nick, "SASL authentication successful"))
+		}
+		return client.Send(MakeMsg(self, ERR_SASLFAIL, client.Nick, "SASL authentication failed"))
+	default:
+		panic(panicSaslMethod)
+	}
+}