This is the v1 version, had the v2 before.

responses/authenticate.go

@@ -0,0 +1,61 @@
+package responses
+
+import (
+	"encoding/base64"
+
+	"github.com/emersion/go-imap"
+	"github.com/emersion/go-sasl"
+)
+
+// An AUTHENTICATE response.
+type Authenticate struct {
+	Mechanism       sasl.Client
+	InitialResponse []byte
+	RepliesCh       chan []byte
+}
+
+// Implements
+func (r *Authenticate) Replies() <-chan []byte {
+	return r.RepliesCh
+}
+
+func (r *Authenticate) writeLine(l string) error {
+	r.RepliesCh <- []byte(l + "\r\n")
+	return nil
+}
+
+func (r *Authenticate) cancel() error {
+	return r.writeLine("*")
+}
+
+func (r *Authenticate) Handle(resp imap.Resp) error {
+	cont, ok := resp.(*imap.ContinuationReq)
+	if !ok {
+		return ErrUnhandled
+	}
+
+	// Empty challenge, send initial response as stated in RFC 2222 section 5.1
+	if cont.Info == "" && r.InitialResponse != nil {
+		encoded := base64.StdEncoding.EncodeToString(r.InitialResponse)
+		if err := r.writeLine(encoded); err != nil {
+			return err
+		}
+		r.InitialResponse = nil
+		return nil
+	}
+
+	challenge, err := base64.StdEncoding.DecodeString(cont.Info)
+	if err != nil {
+		r.cancel()
+		return err
+	}
+
+	reply, err := r.Mechanism.Next(challenge)
+	if err != nil {
+		r.cancel()
+		return err
+	}
+
+	encoded := base64.StdEncoding.EncodeToString(reply)
+	return r.writeLine(encoded)
+}

responses/capability.go

@@ -0,0 +1,20 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+// A CAPABILITY response.
+// See RFC 3501 section 7.2.1
+type Capability struct {
+	Caps []string
+}
+
+func (r *Capability) WriteTo(w *imap.Writer) error {
+	fields := []interface{}{imap.RawString("CAPABILITY")}
+	for _, cap := range r.Caps {
+		fields = append(fields, imap.RawString(cap))
+	}
+
+	return imap.NewUntaggedResp(fields).WriteTo(w)
+}

responses/enabled.go

@@ -0,0 +1,33 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+// An ENABLED response, defined in RFC 5161 section 3.2.
+type Enabled struct {
+	Caps []string
+}
+
+func (r *Enabled) Handle(resp imap.Resp) error {
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != "ENABLED" {
+		return ErrUnhandled
+	}
+
+	if caps, err := imap.ParseStringList(fields); err != nil {
+		return err
+	} else {
+		r.Caps = append(r.Caps, caps...)
+	}
+
+	return nil
+}
+
+func (r *Enabled) WriteTo(w *imap.Writer) error {
+	fields := []interface{}{imap.RawString("ENABLED")}
+	for _, cap := range r.Caps {
+		fields = append(fields, imap.RawString(cap))
+	}
+	return imap.NewUntaggedResp(fields).WriteTo(w)
+}

responses/expunge.go

@@ -0,0 +1,43 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+const expungeName = "EXPUNGE"
+
+// An EXPUNGE response.
+// See RFC 3501 section 7.4.1
+type Expunge struct {
+	SeqNums chan uint32
+}
+
+func (r *Expunge) Handle(resp imap.Resp) error {
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != expungeName {
+		return ErrUnhandled
+	}
+
+	if len(fields) == 0 {
+		return errNotEnoughFields
+	}
+
+	seqNum, err := imap.ParseNumber(fields[0])
+	if err != nil {
+		return err
+	}
+
+	r.SeqNums <- seqNum
+	return nil
+}
+
+func (r *Expunge) WriteTo(w *imap.Writer) error {
+	for seqNum := range r.SeqNums {
+		resp := imap.NewUntaggedResp([]interface{}{seqNum, imap.RawString(expungeName)})
+		if err := resp.WriteTo(w); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

responses/fetch.go

@@ -0,0 +1,70 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+const fetchName = "FETCH"
+
+// A FETCH response.
+// See RFC 3501 section 7.4.2
+type Fetch struct {
+	Messages chan *imap.Message
+	SeqSet   *imap.SeqSet
+	Uid      bool
+}
+
+func (r *Fetch) Handle(resp imap.Resp) error {
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != fetchName {
+		return ErrUnhandled
+	} else if len(fields) < 1 {
+		return errNotEnoughFields
+	}
+
+	seqNum, err := imap.ParseNumber(fields[0])
+	if err != nil {
+		return err
+	}
+
+	msgFields, _ := fields[1].([]interface{})
+	msg := &imap.Message{SeqNum: seqNum}
+	if err := msg.Parse(msgFields); err != nil {
+		return err
+	}
+
+	if r.Uid && msg.Uid == 0 {
+		// we requested UIDs and got a message without one --> unilateral update --> ignore
+		return ErrUnhandled
+	}
+
+	var num uint32
+	if r.Uid {
+		num = msg.Uid
+	} else {
+		num = seqNum
+	}
+
+	// Check whether we obtained a result we requested with our SeqSet
+	// If the result is not contained in our SeqSet we have to handle an additional special case:
+	// In case we requested UIDs with a dynamic sequence (i.e. * or n:*) and the maximum UID of the mailbox
+	// is less then our n, the server will supply us with the max UID (cf. RFC 3501 §6.4.8 and §9 `seq-range`).
+	// Thus, such a result is correct and has to be returned by us.
+	if !r.SeqSet.Contains(num) && (!r.Uid || !r.SeqSet.Dynamic()) {
+		return ErrUnhandled
+	}
+
+	r.Messages <- msg
+	return nil
+}
+
+func (r *Fetch) WriteTo(w *imap.Writer) error {
+	var err error
+	for msg := range r.Messages {
+		resp := imap.NewUntaggedResp([]interface{}{msg.SeqNum, imap.RawString(fetchName), msg.Format()})
+		if err == nil {
+			err = resp.WriteTo(w)
+		}
+	}
+	return err
+}

responses/idle.go

@@ -0,0 +1,38 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+// An IDLE response.
+type Idle struct {
+	RepliesCh chan []byte
+	Stop      <-chan struct{}
+
+	gotContinuationReq bool
+}
+
+func (r *Idle) Replies() <-chan []byte {
+	return r.RepliesCh
+}
+
+func (r *Idle) stop() {
+	r.RepliesCh <- []byte("DONE\r\n")
+}
+
+func (r *Idle) Handle(resp imap.Resp) error {
+	// Wait for a continuation request
+	if _, ok := resp.(*imap.ContinuationReq); ok && !r.gotContinuationReq {
+		r.gotContinuationReq = true
+
+		// We got a continuation request, wait for r.Stop to be closed
+		go func() {
+			<-r.Stop
+			r.stop()
+		}()
+
+		return nil
+	}
+
+	return ErrUnhandled
+}

responses/list.go

@@ -0,0 +1,57 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+const (
+	listName = "LIST"
+	lsubName = "LSUB"
+)
+
+// A LIST response.
+// If Subscribed is set to true, LSUB will be used instead.
+// See RFC 3501 section 7.2.2
+type List struct {
+	Mailboxes  chan *imap.MailboxInfo
+	Subscribed bool
+}
+
+func (r *List) Name() string {
+	if r.Subscribed {
+		return lsubName
+	} else {
+		return listName
+	}
+}
+
+func (r *List) Handle(resp imap.Resp) error {
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != r.Name() {
+		return ErrUnhandled
+	}
+
+	mbox := &imap.MailboxInfo{}
+	if err := mbox.Parse(fields); err != nil {
+		return err
+	}
+
+	r.Mailboxes <- mbox
+	return nil
+}
+
+func (r *List) WriteTo(w *imap.Writer) error {
+	respName := r.Name()
+
+	for mbox := range r.Mailboxes {
+		fields := []interface{}{imap.RawString(respName)}
+		fields = append(fields, mbox.Format()...)
+
+		resp := imap.NewUntaggedResp(fields)
+		if err := resp.WriteTo(w); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

responses/list_test.go

@@ -0,0 +1,65 @@
+package responses
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/emersion/go-imap"
+)
+
+func TestListSlashDelimiter(t *testing.T) {
+	mbox := &imap.MailboxInfo{}
+
+	if err := mbox.Parse([]interface{}{
+		[]interface{}{"\\Unseen"},
+		"/",
+		"INBOX",
+	}); err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if response := getListResponse(t, mbox); response != `* LIST (\Unseen) "/" INBOX`+"\r\n" {
+		t.Error("Unexpected response:", response)
+	}
+}
+
+func TestListNILDelimiter(t *testing.T) {
+	mbox := &imap.MailboxInfo{}
+
+	if err := mbox.Parse([]interface{}{
+		[]interface{}{"\\Unseen"},
+		nil,
+		"INBOX",
+	}); err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if response := getListResponse(t, mbox); response != `* LIST (\Unseen) NIL INBOX`+"\r\n" {
+		t.Error("Unexpected response:", response)
+	}
+}
+
+func newListResponse(mbox *imap.MailboxInfo) (l *List) {
+	l = &List{Mailboxes: make(chan *imap.MailboxInfo)}
+
+	go func() {
+		l.Mailboxes <- mbox
+		close(l.Mailboxes)
+	}()
+
+	return
+}
+
+func getListResponse(t *testing.T, mbox *imap.MailboxInfo) string {
+	b := &bytes.Buffer{}
+	w := imap.NewWriter(b)
+
+	if err := newListResponse(mbox).WriteTo(w); err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	return b.String()
+}

responses/responses.go

@@ -0,0 +1,35 @@
+// IMAP responses defined in RFC 3501.
+package responses
+
+import (
+	"errors"
+
+	"github.com/emersion/go-imap"
+)
+
+// ErrUnhandled is used when a response hasn't been handled.
+var ErrUnhandled = errors.New("imap: unhandled response")
+
+var errNotEnoughFields = errors.New("imap: not enough fields in response")
+
+// Handler handles responses.
+type Handler interface {
+	// Handle processes a response. If the response cannot be processed,
+	// ErrUnhandledResp must be returned.
+	Handle(resp imap.Resp) error
+}
+
+// HandlerFunc is a function that handles responses.
+type HandlerFunc func(resp imap.Resp) error
+
+// Handle implements Handler.
+func (f HandlerFunc) Handle(resp imap.Resp) error {
+	return f(resp)
+}
+
+// Replier is a Handler that needs to send raw data (for instance
+// AUTHENTICATE).
+type Replier interface {
+	Handler
+	Replies() <-chan []byte
+}

responses/search.go

@@ -0,0 +1,41 @@
+package responses
+
+import (
+	"github.com/emersion/go-imap"
+)
+
+const searchName = "SEARCH"
+
+// A SEARCH response.
+// See RFC 3501 section 7.2.5
+type Search struct {
+	Ids []uint32
+}
+
+func (r *Search) Handle(resp imap.Resp) error {
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != searchName {
+		return ErrUnhandled
+	}
+
+	r.Ids = make([]uint32, len(fields))
+	for i, f := range fields {
+		if id, err := imap.ParseNumber(f); err != nil {
+			return err
+		} else {
+			r.Ids[i] = id
+		}
+	}
+
+	return nil
+}
+
+func (r *Search) WriteTo(w *imap.Writer) (err error) {
+	fields := []interface{}{imap.RawString(searchName)}
+	for _, id := range r.Ids {
+		fields = append(fields, id)
+	}
+
+	resp := imap.NewUntaggedResp(fields)
+	return resp.WriteTo(w)
+}

responses/select.go

@@ -0,0 +1,142 @@
+package responses
+
+import (
+	"fmt"
+
+	"github.com/emersion/go-imap"
+)
+
+// A SELECT response.
+type Select struct {
+	Mailbox *imap.MailboxStatus
+}
+
+func (r *Select) Handle(resp imap.Resp) error {
+	if r.Mailbox == nil {
+		r.Mailbox = &imap.MailboxStatus{Items: make(map[imap.StatusItem]interface{})}
+	}
+	mbox := r.Mailbox
+
+	switch resp := resp.(type) {
+	case *imap.DataResp:
+		name, fields, ok := imap.ParseNamedResp(resp)
+		if !ok || name != "FLAGS" {
+			return ErrUnhandled
+		} else if len(fields) < 1 {
+			return errNotEnoughFields
+		}
+
+		flags, _ := fields[0].([]interface{})
+		mbox.Flags, _ = imap.ParseStringList(flags)
+	case *imap.StatusResp:
+		if len(resp.Arguments) < 1 {
+			return ErrUnhandled
+		}
+
+		var item imap.StatusItem
+		switch resp.Code {
+		case "UNSEEN":
+			mbox.UnseenSeqNum, _ = imap.ParseNumber(resp.Arguments[0])
+		case "PERMANENTFLAGS":
+			flags, _ := resp.Arguments[0].([]interface{})
+			mbox.PermanentFlags, _ = imap.ParseStringList(flags)
+		case "UIDNEXT":
+			mbox.UidNext, _ = imap.ParseNumber(resp.Arguments[0])
+			item = imap.StatusUidNext
+		case "UIDVALIDITY":
+			mbox.UidValidity, _ = imap.ParseNumber(resp.Arguments[0])
+			item = imap.StatusUidValidity
+		default:
+			return ErrUnhandled
+		}
+
+		if item != "" {
+			mbox.ItemsLocker.Lock()
+			mbox.Items[item] = nil
+			mbox.ItemsLocker.Unlock()
+		}
+	default:
+		return ErrUnhandled
+	}
+	return nil
+}
+
+func (r *Select) WriteTo(w *imap.Writer) error {
+	mbox := r.Mailbox
+
+	if mbox.Flags != nil {
+		flags := make([]interface{}, len(mbox.Flags))
+		for i, f := range mbox.Flags {
+			flags[i] = imap.RawString(f)
+		}
+		res := imap.NewUntaggedResp([]interface{}{imap.RawString("FLAGS"), flags})
+		if err := res.WriteTo(w); err != nil {
+			return err
+		}
+	}
+
+	if mbox.PermanentFlags != nil {
+		flags := make([]interface{}, len(mbox.PermanentFlags))
+		for i, f := range mbox.PermanentFlags {
+			flags[i] = imap.RawString(f)
+		}
+		statusRes := &imap.StatusResp{
+			Type:      imap.StatusRespOk,
+			Code:      imap.CodePermanentFlags,
+			Arguments: []interface{}{flags},
+			Info:      "Flags permitted.",
+		}
+		if err := statusRes.WriteTo(w); err != nil {
+			return err
+		}
+	}
+
+	if mbox.UnseenSeqNum > 0 {
+		statusRes := &imap.StatusResp{
+			Type:      imap.StatusRespOk,
+			Code:      imap.CodeUnseen,
+			Arguments: []interface{}{mbox.UnseenSeqNum},
+			Info:      fmt.Sprintf("Message %d is first unseen", mbox.UnseenSeqNum),
+		}
+		if err := statusRes.WriteTo(w); err != nil {
+			return err
+		}
+	}
+
+	for k := range r.Mailbox.Items {
+		switch k {
+		case imap.StatusMessages:
+			res := imap.NewUntaggedResp([]interface{}{mbox.Messages, imap.RawString("EXISTS")})
+			if err := res.WriteTo(w); err != nil {
+				return err
+			}
+		case imap.StatusRecent:
+			res := imap.NewUntaggedResp([]interface{}{mbox.Recent, imap.RawString("RECENT")})
+			if err := res.WriteTo(w); err != nil {
+				return err
+			}
+		case imap.StatusUidNext:
+			statusRes := &imap.StatusResp{
+				Type:      imap.StatusRespOk,
+				Code:      imap.CodeUidNext,
+				Arguments: []interface{}{mbox.UidNext},
+				Info:      "Predicted next UID",
+			}
+			if err := statusRes.WriteTo(w); err != nil {
+				return err
+			}
+		case imap.StatusUidValidity:
+			statusRes := &imap.StatusResp{
+				Type:      imap.StatusRespOk,
+				Code:      imap.CodeUidValidity,
+				Arguments: []interface{}{mbox.UidValidity},
+				Info:      "UIDs valid",
+			}
+			if err := statusRes.WriteTo(w); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}

responses/status.go

@@ -0,0 +1,53 @@
+package responses
+
+import (
+	"errors"
+
+	"github.com/emersion/go-imap"
+	"github.com/emersion/go-imap/utf7"
+)
+
+const statusName = "STATUS"
+
+// A STATUS response.
+// See RFC 3501 section 7.2.4
+type Status struct {
+	Mailbox *imap.MailboxStatus
+}
+
+func (r *Status) Handle(resp imap.Resp) error {
+	if r.Mailbox == nil {
+		r.Mailbox = &imap.MailboxStatus{}
+	}
+	mbox := r.Mailbox
+
+	name, fields, ok := imap.ParseNamedResp(resp)
+	if !ok || name != statusName {
+		return ErrUnhandled
+	} else if len(fields) < 2 {
+		return errNotEnoughFields
+	}
+
+	if name, err := imap.ParseString(fields[0]); err != nil {
+		return err
+	} else if name, err := utf7.Encoding.NewDecoder().String(name); err != nil {
+		return err
+	} else {
+		mbox.Name = imap.CanonicalMailboxName(name)
+	}
+
+	var items []interface{}
+	if items, ok = fields[1].([]interface{}); !ok {
+		return errors.New("STATUS response expects a list as second argument")
+	}
+
+	mbox.Items = nil
+	return mbox.Parse(items)
+}
+
+func (r *Status) WriteTo(w *imap.Writer) error {
+	mbox := r.Mailbox
+	name, _ := utf7.Encoding.NewEncoder().String(mbox.Name)
+	fields := []interface{}{imap.RawString(statusName), imap.FormatMailboxName(name), mbox.Format()}
+	return imap.NewUntaggedResp(fields).WriteTo(w)
+}