Initial implementation of Dovecot SASL endpoint

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/emersion/go-msgauth v0.4.1-0.20200429175443-e4c87369d72f
 	github.com/emersion/go-sasl v0.0.0-20191210011802-430746ea8b9b
 	github.com/emersion/go-smtp v0.12.2-0.20200219094142-f9be832b5554
-	github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504181415-c4db6731332d // indirect
+	github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504194015-e35592c01a2c
 	github.com/foxcpp/go-imap-i18nlevel v0.0.0-20200208001533-d6ec88553005
 	github.com/foxcpp/go-imap-sql v0.4.1-0.20200426175844-c3172a53940a
 	github.com/foxcpp/go-mockdns v0.0.0-20200503193630-ff72b88723f2

go.sum

@@ -62,6 +62,10 @@ github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504173201-4582a99ffc3f h1:eT/8SMQq
 github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504173201-4582a99ffc3f/go.mod h1:5yZUmwr851vgjyAfN7OEfnrmKOh/qLA5dbGelXYsu1E=
 github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504181415-c4db6731332d h1:R2o7Kw2CJEy2N8ycjDxFTMxU0xp8gsGv7ZjWyR65LQs=
 github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504181415-c4db6731332d/go.mod h1:5yZUmwr851vgjyAfN7OEfnrmKOh/qLA5dbGelXYsu1E=
+github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504192305-6a7652986e8b h1:gx69er1ld3fIIECH3bDqdS5SOHKQ9KwlXrBkE3FGBEY=
+github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504192305-6a7652986e8b/go.mod h1:5yZUmwr851vgjyAfN7OEfnrmKOh/qLA5dbGelXYsu1E=
+github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504194015-e35592c01a2c h1:P47zvAdjLcQU1UouNlJSVWN1Pg0S7QX8pWKFBWKqCCg=
+github.com/foxcpp/go-dovecot-sasl v0.0.0-20200504194015-e35592c01a2c/go.mod h1:5yZUmwr851vgjyAfN7OEfnrmKOh/qLA5dbGelXYsu1E=
 github.com/foxcpp/go-imap-backend-tests v0.0.0-20200426175250-4110e9b66176 h1:qyze36XjZnwK9geEzr5qlChS8zJgz7L+YZ5O8JNhh90=
 github.com/foxcpp/go-imap-backend-tests v0.0.0-20200426175250-4110e9b66176/go.mod h1:yUISYv/uXLQ6tQZcds/p/hdcZ5JzrEUifyED2VffWpc=
 github.com/foxcpp/go-imap-i18nlevel v0.0.0-20200208001533-d6ec88553005 h1:pfoFtkTTQ473qStSN79jhCFBWqMQt/3DQ3NGuXvT+50=

internal/endpoint/dovecot_sasld/dovecot_sasl.go

@@ -0,0 +1,98 @@
+package dovecotsasld
+
+import (
+	"fmt"
+	"net"
+	"sync"
+
+	"github.com/emersion/go-sasl"
+	dovecotsasl "github.com/foxcpp/go-dovecot-sasl"
+	"github.com/foxcpp/maddy/internal/auth"
+	"github.com/foxcpp/maddy/internal/config"
+	"github.com/foxcpp/maddy/internal/log"
+	"github.com/foxcpp/maddy/internal/module"
+)
+
+const modName = "dovecot_sasld"
+
+type Endpoint struct {
+	addrs    []string
+	log      log.Logger
+	saslAuth auth.SASLAuth
+
+	listenersWg sync.WaitGroup
+
+	srv *dovecotsasl.Server
+}
+
+func New(_ string, addrs []string) (module.Module, error) {
+	return &Endpoint{
+		addrs: addrs,
+		saslAuth: auth.SASLAuth{
+			Log: log.Logger{Name: modName + "/saslauth"},
+		},
+		log: log.Logger{Name: modName, Debug: log.DefaultLogger.Debug},
+	}, nil
+}
+
+func (endp *Endpoint) Name() string {
+	return modName
+}
+
+func (endp *Endpoint) InstanceName() string {
+	return modName
+}
+
+func (endp *Endpoint) Init(cfg *config.Map) error {
+	cfg.Callback("auth", func(m *config.Map, node config.Node) error {
+		return endp.saslAuth.AddProvider(m, node)
+	})
+	if _, err := cfg.Process(); err != nil {
+		return err
+	}
+
+	endp.srv = dovecotsasl.NewServer()
+
+	for _, mech := range endp.saslAuth.SASLMechanisms() {
+		mech := mech
+		endp.srv.AddMechanism(mech, mechInfo[mech], func(req *dovecotsasl.AuthReq) sasl.Server {
+			var remoteAddr net.Addr
+			if req.RemoteIP != nil && req.RemotePort != 0 {
+				remoteAddr = &net.TCPAddr{IP: req.RemoteIP, Port: int(req.RemotePort)}
+			}
+
+			return endp.saslAuth.CreateSASL(mech, remoteAddr, func(_ string) error { return nil })
+		})
+	}
+
+	for _, addr := range endp.addrs {
+		parsed, err := config.ParseEndpoint(addr)
+		if err != nil {
+			return fmt.Errorf("%s: %v", modName, err)
+		}
+
+		l, err := net.Listen(parsed.Network(), parsed.Address())
+		if err != nil {
+			return fmt.Errorf("%s: %v", modName, err)
+		}
+		endp.log.Printf("listening on %v", modName, l.Addr())
+
+		endp.listenersWg.Add(1)
+		go func() {
+			defer endp.listenersWg.Done()
+			if err := endp.srv.Serve(l); err != nil {
+				endp.log.Printf("failed to serve %v: %v", modName, l.Addr(), err)
+			}
+		}()
+	}
+
+	return nil
+}
+
+func (endp *Endpoint) Close() error {
+	return endp.srv.Close()
+}
+
+func init() {
+	module.RegisterEndpoint(modName, New)
+}

internal/endpoint/dovecot_sasld/mech_info.go

@@ -0,0 +1,5 @@
+package dovecotsasld
+
+import dovecotsasl "github.com/foxcpp/go-dovecot-sasl"
+
+var mechInfo = map[string]dovecotsasl.Mechanism{}

maddy.go

@@ -32,6 +32,7 @@ import (
 	_ "github.com/foxcpp/maddy/internal/check/milter"
 	_ "github.com/foxcpp/maddy/internal/check/requiretls"
 	_ "github.com/foxcpp/maddy/internal/check/spf"
+	_ "github.com/foxcpp/maddy/internal/endpoint/dovecot_sasld"
 	_ "github.com/foxcpp/maddy/internal/endpoint/imap"
 	_ "github.com/foxcpp/maddy/internal/endpoint/smtp"
 	_ "github.com/foxcpp/maddy/internal/modify"