feat(imap): postkasser kan læses, og det er bevist mod en rigtig server

Handlere til at forbinde, koble fra og hente nu, plus baggrundssynk hvert tiende
minut ved siden af Gmails. Forbindelsen prøves FØR den gemmes: en postkasse, der
blev taget imod og så fejler stille hvert tiende minut, er værre end en, der blev
afvist ved døren, mens man stadig sidder med kodeordet i hånden.

Ingen "set"-liste til deduplikering som Gmail har. Uid'er er monotone, så
last_uid er hele svaret — og den skrives også, når budgettet løb ud, for en
kørsel, der lavede opgaver og glemte hvor langt den nåede, laver dem alle igen
næste gang.

Rundturen køres nu mod go-imap's egen server i processen: flaget post kommer med,
uflaget gør ikke, og fortsættelsen fra et uid henter kun det nyere. De hidtidige
prøver dækkede de rene dele og ville alle have bestået med selve hentningen i
stykker.

Testen kræver et selvsigneret certifikat, og klienten nægter dem. Account.RootCAs
lader en test TILFØJE tillid; der er stadig ingen måde at fjerne den på. Forskellen
er en søm og ikke et hul — en prøve viser, at samme server afvises uden.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cmd/verdande/main.go

@@ -74,6 +74,7 @@ func run() error {
 	defer stopJobs()
 	runner := jobs.New(cfg, db, log, api.Mail(), api.Hub())
 	runner.SyncGmail = api.SyncGmail
+	runner.SyncMailbox = api.SyncMailbox
 	runner.Start(jobCtx)
 
 	srv := &http.Server{

internal/httpapi/errors.go

@@ -58,6 +58,11 @@ const (
 	// read "something went wrong", and had nowhere to go. The interface wraps the
 	// message in one that says where it came from.
 	CodeGmailFailed = "gmail_failed"
+
+	// And the same for a mailbox read over IMAP. A host's refusal is the whole
+	// diagnosis — a wrong app password, a host that is not listening, a folder that
+	// is not there — and it says it in its own words.
+	CodeMailboxFailed = "mailbox_failed"
 )
 
 // errLastAdmin is returned to the caller that already wrote the response, so it

internal/httpapi/mailbox_handlers.go

@@ -0,0 +1,211 @@
+package httpapi
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/kristianwind/verdande/internal/imap"
+	"github.com/kristianwind/verdande/internal/store"
+)
+
+// defaultMailboxSyncBudget bounds one read of one mailbox when somebody is waiting.
+// The same reasoning as Gmail's: a mailbox that has stopped answering must not
+// hold a request open until whatever sits in front of this server answers for it.
+const defaultMailboxSyncBudget = 25 * time.Second
+
+func (s *Server) handleListMailboxes(w http.ResponseWriter, r *http.Request) {
+	user := userFrom(r.Context())
+	list, err := s.db.Mailboxes(r.Context(), user.ID)
+	if err != nil {
+		s.internal(w, r, "list mailboxes", err)
+		return
+	}
+	if list == nil {
+		list = []store.Mailbox{}
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"mailboxes": list})
+}
+
+// handleAddMailbox connects one, after proving it can actually be read.
+//
+// Tested before it is saved, not after: a mailbox that was accepted and then
+// silently fails every ten minutes is worse than one that refused at the door,
+// where the person is still holding the password they just typed.
+func (s *Server) handleAddMailbox(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Name     string `json:"name"`
+		Host     string `json:"host"`
+		Username string `json:"username"`
+		Password string `json:"password"`
+		Folder   string `json:"folder"`
+	}
+	if err := decodeJSON(w, r, &body); err != nil {
+		return
+	}
+
+	body.Host = strings.TrimSpace(body.Host)
+	body.Username = strings.TrimSpace(body.Username)
+	if body.Host == "" || body.Username == "" || body.Password == "" {
+		writeError(w, http.StatusBadRequest, CodeValidation,
+			"a mailbox needs a host, a username and a password")
+		return
+	}
+	// A host with no port is the mistake everyone makes once, and 993 is the answer
+	// for every host worth naming.
+	if !strings.Contains(body.Host, ":") {
+		body.Host += ":993"
+	}
+
+	account := imap.Account{
+		Host: body.Host, Username: body.Username,
+		Password: body.Password, Folder: body.Folder,
+	}
+	client, err := imap.Dial(account)
+	if err != nil {
+		s.upstream(w, r, CodeMailboxFailed, "connect mailbox", err)
+		return
+	}
+	client.Close()
+
+	user := userFrom(r.Context())
+	m := &store.Mailbox{
+		UserID: user.ID, Kind: "imap", Name: strings.TrimSpace(body.Name),
+		Host: body.Host, Username: body.Username,
+		Password: body.Password, Folder: body.Folder,
+	}
+	if m.Name == "" {
+		m.Name = body.Username
+	}
+	if err := s.db.SaveMailbox(r.Context(), m); err != nil {
+		// The unique index. Saying which mailbox is already here beats "constraint
+		// failed", which is true and useless.
+		if strings.Contains(err.Error(), "UNIQUE") {
+			writeError(w, http.StatusConflict, CodeValidation,
+				fmt.Sprintf("%s on %s is already connected", body.Username, body.Host))
+			return
+		}
+		s.internal(w, r, "save mailbox", err)
+		return
+	}
+	writeJSON(w, http.StatusCreated, m)
+}
+
+func (s *Server) handleDeleteMailbox(w http.ResponseWriter, r *http.Request) {
+	user := userFrom(r.Context())
+	if err := s.db.DeleteMailbox(r.Context(), user.ID, chi.URLParam(r, "mailboxID")); err != nil {
+		s.internal(w, r, "delete mailbox", err)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// handleSyncMailbox reads one mailbox now, within a budget of its own.
+func (s *Server) handleSyncMailbox(w http.ResponseWriter, r *http.Request) {
+	user := userFrom(r.Context())
+	m, err := s.db.Mailbox(r.Context(), user.ID, chi.URLParam(r, "mailboxID"))
+	if err != nil {
+		s.internal(w, r, "read mailbox", err)
+		return
+	}
+	if m == nil {
+		writeError(w, http.StatusNotFound, CodeNotFound, "no such mailbox")
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), defaultMailboxSyncBudget)
+	defer cancel()
+
+	created, err := s.SyncMailbox(ctx, user, m)
+	if err != nil {
+		// Whatever was made by the deadline is kept: each task is committed as it
+		// is made, so a short budget is a shorter run rather than a lost one.
+		if errors.Is(err, context.DeadlineExceeded) {
+			writeJSON(w, http.StatusOK, map[string]any{"created": created, "partial": true})
+			return
+		}
+		s.upstream(w, r, CodeMailboxFailed, "sync mailbox", err)
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"created": created})
+}
+
+// SyncMailbox turns the flagged mail newer than the last run into tasks.
+//
+// Exported because the background job calls it too, on the same terms and without
+// a budget: nobody is waiting there.
+func (s *Server) SyncMailbox(ctx context.Context, user *store.User, m *store.Mailbox) (int, error) {
+	client, err := imap.Dial(imap.Account{
+		Host: m.Host, Username: m.Username, Password: m.Password, Folder: m.Folder,
+	})
+	if err != nil {
+		return 0, err
+	}
+	defer client.Close()
+
+	messages, err := client.Since(m.LastUID, 25)
+	if err != nil {
+		return 0, err
+	}
+	if len(messages) == 0 {
+		return 0, nil
+	}
+
+	projectID, err := s.db.InboxID(ctx, user.ID)
+	if err != nil {
+		return 0, err
+	}
+
+	created := 0
+	highest := m.LastUID
+	for _, msg := range messages {
+		if ctx.Err() != nil {
+			// What was made so far is already committed and counted, and the marker
+			// below has to be written for it: a run that created tasks and forgot how
+			// far it got would make them all again on the next pass.
+			break
+		}
+
+		subject := msg.Subject
+		if subject == "" {
+			subject = "(uden emne)"
+		}
+		content := subject
+		if msg.From != "" {
+			content = msg.From + ": " + subject
+		}
+
+		task := &store.Task{
+			ProjectID:   projectID,
+			Content:     content,
+			Description: msg.Snippet,
+			Priority:    4,
+			CreatedBy:   user.ID,
+		}
+		if err := s.db.CreateTask(ctx, task, nil); err != nil {
+			s.log.Warn("mailbox create task", "err", err, "mailbox", m.ID)
+			continue
+		}
+		created++
+		if msg.UID > highest {
+			highest = msg.UID
+		}
+		s.hub.Publish(projectID, "task.created", toTaskJSON(*task))
+	}
+
+	// Written even when the loop was cut short, and outside the request's context
+	// so a cancelled request still records what it did.
+	if highest > m.LastUID {
+		if err := s.db.MarkMailboxRead(context.WithoutCancel(ctx), m.ID, highest, time.Now()); err != nil {
+			s.log.Warn("mark mailbox read", "err", err, "mailbox", m.ID)
+		}
+	}
+	if ctx.Err() != nil {
+		return created, ctx.Err()
+	}
+	return created, nil
+}

internal/httpapi/server.go

@@ -260,6 +260,16 @@ func New(cfg *config.Config, db *store.DB, log *slog.Logger, web fs.FS) *Server
 
 			r.Get("/version", s.handleVersion)
 
+			// Mailboxes read over IMAP — iCloud, Fastmail, any ordinary host. Each
+			// belongs to the person who connected it, so there is no admin gate
+			// here and no shared registration: the credential is theirs.
+			r.Route("/mailboxes", func(r chi.Router) {
+				r.Get("/", s.handleListMailboxes)
+				r.Post("/", s.handleAddMailbox)
+				r.Delete("/{mailboxID}", s.handleDeleteMailbox)
+				r.Post("/{mailboxID}/sync", s.handleSyncMailbox)
+			})
+
 			r.Route("/gmail", func(r chi.Router) {
 				r.Get("/", s.handleGetGmail)
 				r.Put("/", s.handleSetGmail)

internal/imap/imap.go

@@ -17,6 +17,7 @@ package imap
 
 import (
 	"crypto/tls"
+	"crypto/x509"
 	"fmt"
 	"net"
 	"strings"
@@ -41,6 +42,13 @@ type Account struct {
 	Username string
 	Password string // an app-specific password on every host worth naming
 	Folder   string // "INBOX" when empty
+
+	// RootCAs adds a certificate authority to trust, on top of the system's. It
+	// exists so a test can put a real IMAP server behind a self-signed certificate
+	// and still be refused by everything else — the field can only widen trust,
+	// never switch verification off, which is the difference between a seam and a
+	// hole. Nil in production, where the system's roots are the answer.
+	RootCAs *x509.CertPool
 }
 
 // Dial opens a TLS connection and logs in. The caller closes it.
@@ -55,7 +63,11 @@ func Dial(a Account) (*Client, error) {
 	}
 
 	c, err := imapclient.DialTLS(a.Host, &imapclient.Options{
-		TLSConfig: &tls.Config{ServerName: host, MinVersion: tls.VersionTLS12},
+		TLSConfig: &tls.Config{
+			ServerName: host,
+			MinVersion: tls.VersionTLS12,
+			RootCAs:    a.RootCAs,
+		},
 	})
 	if err != nil {
 		return nil, fmt.Errorf("connect to %s: %w", a.Host, err)

internal/imap/roundtrip_test.go

@@ -0,0 +1,183 @@
+package imap
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"math/big"
+	"net"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/emersion/go-imap/v2"
+	"github.com/emersion/go-imap/v2/imapserver"
+	"github.com/emersion/go-imap/v2/imapserver/imapmemserver"
+)
+
+// The round trip, against a real IMAP server rather than a stub of one. The
+// earlier tests cover the pure parts — what a sender renders as, where a snippet
+// is cut — and would all have passed with the fetch itself broken.
+func TestFlaggedMailComesBackAsMessages(t *testing.T) {
+	addr, pool := serveMailbox(t, []mail{
+		{subject: "Faktura 4711", from: "Anders Bo <anders@example.dk>", body: "Vedhæftet.", flagged: true},
+		{subject: "Nyhedsbrev", from: "noreply@example.com", body: "Læs mere", flagged: false},
+		{subject: "Kontrakt", from: "jura@example.dk", body: "Til underskrift", flagged: true},
+	})
+
+	client, err := Dial(Account{
+		Host: addr, Username: "kw", Password: "hemmelig", RootCAs: pool,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer client.Close()
+
+	msgs, err := client.Since(0, 25)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Two of the three. The newsletter is unflagged, and flagging is the whole
+	// signal: unread is a state the owner is still using.
+	if len(msgs) != 2 {
+		t.Fatalf("got %d messages, want the 2 flagged ones", len(msgs))
+	}
+	if msgs[0].Subject != "Faktura 4711" {
+		t.Errorf("first subject is %q", msgs[0].Subject)
+	}
+	if !strings.Contains(msgs[0].From, "anders@example.dk") {
+		t.Errorf("first sender is %q", msgs[0].From)
+	}
+	if msgs[0].UID == 0 {
+		t.Error("no uid came back, so a second run would fetch everything again")
+	}
+
+	// And reading on from a marker returns only what is newer, which is the whole
+	// of the deduplication.
+	rest, err := client.Since(msgs[0].UID, 25)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rest) != 1 || rest[0].Subject != "Kontrakt" {
+		t.Fatalf("reading on from uid %d gave %d messages", msgs[0].UID, len(rest))
+	}
+}
+
+func TestAWrongPasswordIsRefusedClearly(t *testing.T) {
+	addr, pool := serveMailbox(t, nil)
+	_, err := Dial(Account{Host: addr, Username: "kw", Password: "forkert", RootCAs: pool})
+	if err == nil {
+		t.Fatal("a wrong password was accepted")
+	}
+	// Hosts say everything from AUTHENTICATIONFAILED to a sentence about the web,
+	// so the reply names the host and the user rather than repeating their words.
+	if !strings.Contains(err.Error(), "kw") {
+		t.Errorf("the error does not say whose login was refused: %v", err)
+	}
+}
+
+// A certificate this process signed itself must not be enough on its own.
+func TestAnUntrustedCertificateIsRefused(t *testing.T) {
+	addr, _ := serveMailbox(t, nil)
+	if _, err := Dial(Account{Host: addr, Username: "kw", Password: "hemmelig"}); err == nil {
+		t.Fatal("a self-signed certificate was accepted without being trusted")
+	}
+}
+
+type mail struct {
+	subject, from, body string
+	flagged             bool
+}
+
+// serveMailbox starts an in-process IMAP server over TLS and returns its address
+// and the pool that trusts it.
+func serveMailbox(t *testing.T, mails []mail) (string, *x509.CertPool) {
+	t.Helper()
+
+	cert, pool := selfSigned(t)
+	memServer := imapmemserver.New()
+	user := imapmemserver.NewUser("kw", "hemmelig")
+	if err := user.Create("INBOX", nil); err != nil {
+		t.Fatal(err)
+	}
+	memServer.AddUser(user)
+
+	for _, m := range mails {
+		flags := []imap.Flag{}
+		if m.flagged {
+			flags = append(flags, imap.FlagFlagged)
+		}
+		raw := "From: " + m.from + "\r\nSubject: " + m.subject +
+			"\r\nDate: Tue, 18 Aug 2026 10:00:00 +0200\r\n\r\n" + m.body + "\r\n"
+		if _, err := user.Append("INBOX", strings.NewReader(raw), &imap.AppendOptions{
+			Flags: flags,
+		}); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	srv := imapserver.New(&imapserver.Options{
+		NewSession: func(_ *imapserver.Conn) (imapserver.Session, *imapserver.GreetingData, error) {
+			return memServer.NewSession(), nil, nil
+		},
+		TLSConfig:    &tls.Config{Certificates: []tls.Certificate{cert}},
+		InsecureAuth: false,
+	})
+	t.Cleanup(func() { srv.Close() })
+
+	ln, err := tls.Listen("tcp", "127.0.0.1:0", &tls.Config{Certificates: []tls.Certificate{cert}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	go srv.Serve(ln)
+
+	// "localhost", not the loopback address: the certificate names a host, and the
+	// client checks that name — as it should.
+	_, port, _ := net.SplitHostPort(ln.Addr().String())
+	return net.JoinHostPort("localhost", port), pool
+}
+
+func selfSigned(t *testing.T) (tls.Certificate, *x509.CertPool) {
+	t.Helper()
+
+	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	template := x509.Certificate{
+		SerialNumber:          big.NewInt(1),
+		Subject:               pkix.Name{CommonName: "localhost"},
+		DNSNames:              []string{"localhost"},
+		IPAddresses:           []net.IP{net.ParseIP("127.0.0.1")},
+		NotBefore:             time.Now().Add(-time.Hour),
+		NotAfter:              time.Now().Add(time.Hour),
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		IsCA:                  true,
+		BasicConstraintsValid: true,
+	}
+	der, err := x509.CreateCertificate(rand.Reader, &template, &template, &key.PublicKey, key)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der})
+	keyDER, err := x509.MarshalECPrivateKey(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	keyPEM := pem.EncodeToMemory(&pem.Block{Type: "EC PRIVATE KEY", Bytes: keyDER})
+
+	cert, err := tls.X509KeyPair(certPEM, keyPEM)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pool := x509.NewCertPool()
+	pool.AppendCertsFromPEM(certPEM)
+	return cert, pool
+}

internal/jobs/jobs.go

@@ -37,6 +37,10 @@ type Runner struct {
 	// startable from main.
 	SyncGmail func(ctx context.Context, user *store.User) (int, error)
 
+	// SyncMailbox reads one IMAP mailbox. Supplied by the HTTP layer for the same
+	// reason as SyncGmail: it owns turning a message into a task.
+	SyncMailbox func(ctx context.Context, user *store.User, m *store.Mailbox) (int, error)
+
 	wg sync.WaitGroup
 }
 
@@ -61,6 +65,7 @@ func (r *Runner) Start(ctx context.Context) {
 	// account for a to-do app. Ten minutes is fast enough for something somebody
 	// starred and slow enough not to look like abuse.
 	r.every(ctx, "gmail", 10*time.Minute, r.syncGmailAccounts)
+	r.every(ctx, "mailboxes", 10*time.Minute, r.syncMailboxes)
 }
 
 func (r *Runner) Wait() { r.wg.Wait() }
@@ -272,6 +277,44 @@ func (r *Runner) syncGmailAccounts(ctx context.Context) error {
 	return nil
 }
 
+// syncMailboxes polls every connected IMAP mailbox.
+//
+// Nobody is waiting, so no budget of its own — the request handler has one because
+// a person is watching a spinner. A host that has gone quiet costs this run its
+// own dial timeout and nothing else: the loop moves on, per mailbox and per
+// person, so one bad password does not stop everybody else's mail.
+func (r *Runner) syncMailboxes(ctx context.Context) error {
+	if r.SyncMailbox == nil {
+		return nil
+	}
+	userIDs, err := r.db.UsersWithMailboxes(ctx)
+	if err != nil {
+		return err
+	}
+	for _, id := range userIDs {
+		user, err := r.db.UserByID(ctx, id)
+		if err != nil || user == nil {
+			continue
+		}
+		boxes, err := r.db.Mailboxes(ctx, id)
+		if err != nil {
+			r.log.Warn("list mailboxes", "err", err, "user", id)
+			continue
+		}
+		for i := range boxes {
+			created, err := r.SyncMailbox(ctx, user, &boxes[i])
+			if err != nil {
+				r.log.Warn("mailbox sync", "err", err, "user", id, "mailbox", boxes[i].ID)
+				continue
+			}
+			if created > 0 {
+				r.log.Info("tasks created from a mailbox", "user", id, "count", created)
+			}
+		}
+	}
+	return nil
+}
+
 // --- housekeeping -----------------------------------------------------------------
 
 func (r *Runner) emptyTrash(ctx context.Context) error {