Phase 3: sending domains + per-domain OpenDKIM signing

Add/list/delete of sending domains with per-domain DKIM keys and the
OpenDKIM tables that drive signing (spec 6, 7.2.2-4, 7.2.10).

internal/domain:
- Pure-Go RSA-2048 keygen; PKCS#1 PEM written atomically at 0640; the
  published DNS TXT record is derived from the key on disk (single source
  of truth) rather than persisted. No os/exec for key generation.
- KeyTable/SigningTable fully regenerated from the registry on every
  add/delete (idempotent), written atomically; SigningTable via refile:
  with *@domain, KeyTable with absolute key paths. Table writer refuses
  any unsafe character as a backstop (spec 7.6.4).
- Reload without root: the unprivileged panel signals OpenDKIM through
  supervisord (`supervisorctl signal USR1 opendkim`, fixed args, no
  shell, no user input — spec 7.6.3). An existing key is reused, never
  overwritten, so re-adding a domain keeps its published DNS valid.
- Service orchestrates registry -> key -> table rebuild -> reload, with
  rollback of the row if a downstream step fails; delete cascades apps
  via the DB FK and removes the key + table entries.

Infra:
- Shared `selfpost` group bridges panel (writes keys) and opendkim
  (reads them); /data/opendkim is setgid so panel-created files inherit
  the group, keys are 0640, RequireSafeKeys is disabled by design.
- opendkim.conf moves from verify-only (Mode v) to signing (Mode s).
- entrypoint.sh normalises the DKIM tree on every start (ownership,
  setgid, perms, empty tables before opendkim starts) — self-healing
  after a restore.
- supervisord control socket opened to the `selfpost` group so the panel
  can request the reload.

web/store:
- Strict domain-name validation (whitelist [a-z0-9.-], DNS shape, >=2
  labels), lower-case normalisation (spec 7.6.2).
- Domain queries with application counts; delete relies on ON DELETE
  CASCADE. Dashboard lists domains + add form; domain page shows the
  DKIM record; a dedicated confirm page warns about the app cascade
  before deletion (spec 7.2.4); manual reload button (spec 7.2.12,
  OpenDKIM side; Postfix reload lands in Phase 5).
- Authenticated routes moved to a sub-mux using Go 1.22 method/wildcard
  patterns.

Tests: validateDomain, DKIM keygen/record roundtrip, table rendering +
injection-safety, key reuse, store cascade. Verified on the dev server:
gofmt/vet/test green, image builds, container e2e (add/delete a domain,
DKIM record shown, OpenDKIM reads panel keys and reloads, keys and
tables persist across a restart).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
2026-07-11 22:20:35 +03:00
parent 048be22ded
commit a7a5ad3f91
24 changed files with 1461 additions and 36 deletions
+127
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// Package domain owns SelfPost's sending-domain model: per-domain DKIM key
// generation, the OpenDKIM KeyTable/SigningTable that drive signing, and the
// orchestration that keeps the SQLite registry, the on-disk keys and OpenDKIM
// in agreement (spec 4.1, 6). Key material lives under /data so it survives
// container restarts (spec 6.1, 9).
package domain
import (
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/base64"
"encoding/pem"
"fmt"
"os"
"path/filepath"
)
// dkimKeyBits is the RSA key size for DKIM signing keys. 2048 is the DKIM
// interoperability sweet spot: strong, and short enough that the published
// public key still fits comfortably in a DNS TXT record.
const dkimKeyBits = 2048
// generateDKIMKey creates a fresh RSA private key for signing a domain.
func generateDKIMKey() (*rsa.PrivateKey, error) {
key, err := rsa.GenerateKey(rand.Reader, dkimKeyBits)
if err != nil {
return nil, fmt.Errorf("generate dkim key: %w", err)
}
return key, nil
}
// writePrivateKeyPEM writes key to path as a PKCS#1 "RSA PRIVATE KEY" PEM,
// atomically and group-readable (0640). The file is owned by the panel user and
// read by OpenDKIM through the shared `selfpost` group (see build/opendkim.conf
// and entrypoint.sh); the parent directory carries setgid so the group is
// inherited. The write is atomic (temp file + rename) so OpenDKIM never observes
// a half-written key.
func writePrivateKeyPEM(path string, key *rsa.PrivateKey) error {
block := &pem.Block{
Type: "RSA PRIVATE KEY",
Bytes: x509.MarshalPKCS1PrivateKey(key),
}
return writeFileAtomic(path, pem.EncodeToMemory(block), 0o640)
}
// loadPrivateKeyPEM reads and parses a PKCS#1 RSA private key written by
// writePrivateKeyPEM. It is used to recompute the public DNS record on demand,
// keeping the private key file the single source of truth (spec 7.2.10).
func loadPrivateKeyPEM(path string) (*rsa.PrivateKey, error) {
data, err := os.ReadFile(path)
if err != nil {
return nil, err
}
block, _ := pem.Decode(data)
if block == nil || block.Type != "RSA PRIVATE KEY" {
return nil, fmt.Errorf("dkim key %s: not a PKCS#1 RSA private key", path)
}
key, err := x509.ParsePKCS1PrivateKey(block.Bytes)
if err != nil {
return nil, fmt.Errorf("parse dkim key %s: %w", path, err)
}
return key, nil
}
// DKIMRecord is the DNS TXT record a user must publish for a domain (spec 7.2.10).
type DKIMRecord struct {
// Name is the record's host, e.g. "selfpost._domainkey.example.com".
Name string
// Value is the TXT payload, e.g. "v=DKIM1; h=sha256; k=rsa; p=MIIB...".
Value string
}
// dkimRecord builds the published DKIM DNS record for a public key. The value
// mirrors what opendkim-genkey emits: v=DKIM1, sha256, RSA, and the public key
// as base64-encoded SubjectPublicKeyInfo (PKIX) DER.
func dkimRecord(selector, domainName string, pub *rsa.PublicKey) (DKIMRecord, error) {
der, err := x509.MarshalPKIXPublicKey(pub)
if err != nil {
return DKIMRecord{}, fmt.Errorf("marshal dkim public key: %w", err)
}
p := base64.StdEncoding.EncodeToString(der)
return DKIMRecord{
Name: fmt.Sprintf("%s._domainkey.%s", selector, domainName),
Value: fmt.Sprintf("v=DKIM1; h=sha256; k=rsa; p=%s", p),
}, nil
}
// writeFileAtomic writes data to path via a temp file in the same directory
// followed by a rename, so readers only ever see the complete old or new file.
// It is the single safe-write primitive for DKIM keys and OpenDKIM tables
// (spec 7.6.4).
func writeFileAtomic(path string, data []byte, perm os.FileMode) error {
dir := filepath.Dir(path)
tmp, err := os.CreateTemp(dir, ".tmp-*")
if err != nil {
return fmt.Errorf("create temp in %s: %w", dir, err)
}
tmpName := tmp.Name()
cleanup := true
defer func() {
if cleanup {
_ = os.Remove(tmpName)
}
}()
if _, err := tmp.Write(data); err != nil {
tmp.Close()
return fmt.Errorf("write temp %s: %w", tmpName, err)
}
if err := tmp.Chmod(perm); err != nil {
tmp.Close()
return fmt.Errorf("chmod temp %s: %w", tmpName, err)
}
if err := tmp.Sync(); err != nil {
tmp.Close()
return fmt.Errorf("sync temp %s: %w", tmpName, err)
}
if err := tmp.Close(); err != nil {
return fmt.Errorf("close temp %s: %w", tmpName, err)
}
if err := os.Rename(tmpName, path); err != nil {
return fmt.Errorf("rename %s -> %s: %w", tmpName, path, err)
}
cleanup = false
return nil
}
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package domain
import (
"os"
"path/filepath"
"strings"
"testing"
)
func TestWriteLoadPrivateKeyRoundtrip(t *testing.T) {
key, err := generateDKIMKey()
if err != nil {
t.Fatalf("generateDKIMKey: %v", err)
}
path := filepath.Join(t.TempDir(), "selfpost.private")
if err := writePrivateKeyPEM(path, key); err != nil {
t.Fatalf("writePrivateKeyPEM: %v", err)
}
info, err := os.Stat(path)
if err != nil {
t.Fatalf("stat: %v", err)
}
if perm := info.Mode().Perm(); perm != 0o640 {
t.Errorf("key perm = %o, want 0640", perm)
}
loaded, err := loadPrivateKeyPEM(path)
if err != nil {
t.Fatalf("loadPrivateKeyPEM: %v", err)
}
if loaded.N.Cmp(key.N) != 0 || loaded.E != key.E {
t.Error("loaded key does not match generated key")
}
}
func TestLoadPrivateKeyRejectsGarbage(t *testing.T) {
path := filepath.Join(t.TempDir(), "bad.private")
if err := os.WriteFile(path, []byte("not a pem"), 0o640); err != nil {
t.Fatal(err)
}
if _, err := loadPrivateKeyPEM(path); err == nil {
t.Error("expected error for non-PEM key file")
}
}
func TestDKIMRecord(t *testing.T) {
key, err := generateDKIMKey()
if err != nil {
t.Fatal(err)
}
rec, err := dkimRecord("selfpost", "example.com", &key.PublicKey)
if err != nil {
t.Fatalf("dkimRecord: %v", err)
}
if rec.Name != "selfpost._domainkey.example.com" {
t.Errorf("record name = %q", rec.Name)
}
for _, want := range []string{"v=DKIM1", "h=sha256", "k=rsa", "p="} {
if !strings.Contains(rec.Value, want) {
t.Errorf("record value %q missing %q", rec.Value, want)
}
}
}
func TestWriteFileAtomicOverwrite(t *testing.T) {
path := filepath.Join(t.TempDir(), "f")
if err := writeFileAtomic(path, []byte("one"), 0o640); err != nil {
t.Fatal(err)
}
if err := writeFileAtomic(path, []byte("two"), 0o640); err != nil {
t.Fatal(err)
}
got, err := os.ReadFile(path)
if err != nil {
t.Fatal(err)
}
if string(got) != "two" {
t.Errorf("content = %q, want %q", got, "two")
}
// No stray temp files left behind in the directory.
entries, _ := os.ReadDir(filepath.Dir(path))
if len(entries) != 1 {
t.Errorf("expected 1 file after atomic writes, found %d", len(entries))
}
}
+184
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package domain
import (
"fmt"
"os"
"os/exec"
"path/filepath"
"sort"
"strings"
)
// OpenDKIM manages the on-disk OpenDKIM state the panel is responsible for
// (spec 6): per-domain signing keys under keysDir and the KeyTable/SigningTable
// that map domains to those keys. After rewriting the tables it asks OpenDKIM to
// reload them.
type OpenDKIM struct {
keysDir string
keyTablePath string
signingTablePath string
// reload sends the running OpenDKIM a reload signal. It is a field so tests
// can substitute a no-op; the default drives supervisord (see reloadViaSupervisor).
reload func() error
}
// NewOpenDKIM builds a manager rooted at dir (typically /data/opendkim), the
// same layout entrypoint.sh prepares. The default reload path signals OpenDKIM
// through supervisord.
func NewOpenDKIM(dir string) *OpenDKIM {
return &OpenDKIM{
keysDir: filepath.Join(dir, "keys"),
keyTablePath: filepath.Join(dir, "KeyTable"),
signingTablePath: filepath.Join(dir, "SigningTable"),
reload: reloadViaSupervisor,
}
}
// SigningDomain is one row's worth of signing configuration.
type SigningDomain struct {
Name string
Selector string
}
// keyPath is the private-key path for a domain/selector, matching the KeyTable.
func (o *OpenDKIM) keyPath(domainName, selector string) string {
return filepath.Join(o.keysDir, domainName, selector+".private")
}
// EnsureKey makes sure a signing key exists for the domain. An existing key is
// reused untouched — critical because overwriting it would silently invalidate
// the DKIM record already published in DNS (spec 6.1). Returns whether a new key
// was generated.
func (o *OpenDKIM) EnsureKey(domainName, selector string) (bool, error) {
if err := assertConfigSafe(domainName, selector); err != nil {
return false, err
}
path := o.keyPath(domainName, selector)
if _, err := os.Stat(path); err == nil {
return false, nil // reuse existing key
} else if !os.IsNotExist(err) {
return false, fmt.Errorf("stat dkim key: %w", err)
}
// setgid on keysDir (entrypoint.sh) makes the per-domain dir inherit the
// shared `selfpost` group so OpenDKIM can traverse into it.
if err := os.MkdirAll(filepath.Dir(path), 0o750); err != nil {
return false, fmt.Errorf("create key dir: %w", err)
}
key, err := generateDKIMKey()
if err != nil {
return false, err
}
if err := writePrivateKeyPEM(path, key); err != nil {
return false, err
}
return true, nil
}
// RemoveKey deletes a domain's key directory (spec 6.5). A missing directory is
// not an error.
func (o *OpenDKIM) RemoveKey(domainName string) error {
if err := assertConfigSafe(domainName, "x"); err != nil {
return err
}
if err := os.RemoveAll(filepath.Join(o.keysDir, domainName)); err != nil {
return fmt.Errorf("remove key dir for %s: %w", domainName, err)
}
return nil
}
// Record returns the published DKIM DNS record for a domain, recomputed from the
// private key on disk (spec 7.2.10).
func (o *OpenDKIM) Record(domainName, selector string) (DKIMRecord, error) {
key, err := loadPrivateKeyPEM(o.keyPath(domainName, selector))
if err != nil {
return DKIMRecord{}, err
}
return dkimRecord(selector, domainName, &key.PublicKey)
}
// Rebuild regenerates KeyTable and SigningTable from the full domain set and
// reloads OpenDKIM (spec 6.2). Full regeneration (rather than incremental
// edits) keeps the files a pure function of the registry, so add and delete
// share one idempotent path. Both files are written atomically before the
// reload signal is sent.
func (o *OpenDKIM) Rebuild(domains []SigningDomain) error {
keyTable, signingTable, err := renderTables(o.keysDir, domains)
if err != nil {
return err
}
if err := writeFileAtomic(o.keyTablePath, keyTable, 0o640); err != nil {
return err
}
if err := writeFileAtomic(o.signingTablePath, signingTable, 0o640); err != nil {
return err
}
return o.reload()
}
// Reload asks OpenDKIM to re-read its tables without regenerating them. It backs
// the panel's manual reload button (spec 7.2.12).
func (o *OpenDKIM) Reload() error {
return o.reload()
}
// renderTables builds the KeyTable and SigningTable byte contents for a domain
// set, sorted by name so the output is deterministic. Every domain is
// re-checked for shell/config-injection safety before being written (spec
// 7.6.4) — validation upstream already guarantees this, but the table writer
// refuses to emit anything unsafe as a hard backstop.
func renderTables(keysDir string, domains []SigningDomain) (keyTable, signingTable []byte, err error) {
sorted := append([]SigningDomain(nil), domains...)
sort.Slice(sorted, func(i, j int) bool { return sorted[i].Name < sorted[j].Name })
var kt, st strings.Builder
for _, d := range sorted {
if err := assertConfigSafe(d.Name, d.Selector); err != nil {
return nil, nil, err
}
keyName := d.Name // one key per domain; the domain name is a fine handle
// Absolute key path so OpenDKIM resolves it independently of its CWD.
keyFile := filepath.Join(keysDir, d.Name, d.Selector+".private")
// KeyTable: <key-name> <domain>:<selector>:<key-path>
fmt.Fprintf(&kt, "%s %s:%s:%s\n", keyName, d.Name, d.Selector, keyFile)
// SigningTable (refile): <address-pattern> <key-name>
fmt.Fprintf(&st, "*@%s %s\n", d.Name, keyName)
}
return []byte(kt.String()), []byte(st.String()), nil
}
// assertConfigSafe rejects any domain/selector value that could break out of a
// single table line. Domains are already whitelisted to [a-z0-9.-] and selectors
// to a similar set before they reach here (spec 7.6.2); this is defence in depth
// against a validation gap ever letting whitespace, a newline or a field
// separator through into a config file (spec 7.6.4).
func assertConfigSafe(domainName, selector string) error {
for _, v := range []string{domainName, selector} {
if v == "" {
return fmt.Errorf("opendkim: empty domain or selector")
}
if strings.ContainsAny(v, " \t\r\n:/\\") {
return fmt.Errorf("opendkim: unsafe character in %q", v)
}
}
return nil
}
// reloadViaSupervisor asks supervisord (PID 1, running as root) to send the
// OpenDKIM process SIGUSR1, which makes it re-read KeyTable/SigningTable
// (opendkim's documented reload signal). The panel runs unprivileged and cannot
// signal another user's process directly, so it goes through the supervisor
// control socket, reachable via the shared `selfpost` group (spec 7.6.3, 7.6.8).
//
// Arguments are fixed literals — no user input is interpolated into the command,
// and it never goes through a shell (spec 7.6.3).
func reloadViaSupervisor() error {
cmd := exec.Command("supervisorctl",
"-c", "/etc/supervisor/supervisord.conf",
"signal", "USR1", "opendkim")
out, err := cmd.CombinedOutput()
if err != nil {
return fmt.Errorf("reload opendkim via supervisor: %w: %s", err, strings.TrimSpace(string(out)))
}
return nil
}
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package domain
import (
"os"
"path/filepath"
"strings"
"testing"
)
func TestRenderTables(t *testing.T) {
keysDir := "/data/opendkim/keys"
// Deliberately out of order to exercise the deterministic sort.
domains := []SigningDomain{
{Name: "zeta.example", Selector: "selfpost"},
{Name: "alpha.example", Selector: "sel2"},
}
kt, st, err := renderTables(keysDir, domains)
if err != nil {
t.Fatalf("renderTables: %v", err)
}
wantKT := "alpha.example alpha.example:sel2:/data/opendkim/keys/alpha.example/sel2.private\n" +
"zeta.example zeta.example:selfpost:/data/opendkim/keys/zeta.example/selfpost.private\n"
if string(kt) != wantKT {
t.Errorf("KeyTable =\n%q\nwant\n%q", kt, wantKT)
}
wantST := "*@alpha.example alpha.example\n*@zeta.example zeta.example\n"
if string(st) != wantST {
t.Errorf("SigningTable =\n%q\nwant\n%q", st, wantST)
}
}
func TestRenderTablesEmpty(t *testing.T) {
kt, st, err := renderTables("/keys", nil)
if err != nil {
t.Fatalf("renderTables(nil): %v", err)
}
if len(kt) != 0 || len(st) != 0 {
t.Errorf("expected empty tables, got kt=%q st=%q", kt, st)
}
}
func TestAssertConfigSafeRejectsInjection(t *testing.T) {
bad := []struct{ name, sel string }{
{"exa mple.com", "selfpost"},
{"example.com\nInject yes", "selfpost"},
{"example.com", "sel:evil"},
{"../etc", "selfpost"},
{"", "selfpost"},
{"example.com", ""},
}
for _, b := range bad {
if err := assertConfigSafe(b.name, b.sel); err == nil {
t.Errorf("assertConfigSafe(%q,%q) = nil, want error", b.name, b.sel)
}
}
if err := assertConfigSafe("example.com", "selfpost"); err != nil {
t.Errorf("assertConfigSafe of a clean pair errored: %v", err)
}
}
// newTestOpenDKIM builds a manager rooted at a temp dir with reload stubbed out.
func newTestOpenDKIM(t *testing.T) (*OpenDKIM, *int) {
t.Helper()
dir := t.TempDir()
if err := os.MkdirAll(filepath.Join(dir, "keys"), 0o750); err != nil {
t.Fatal(err)
}
reloads := 0
o := NewOpenDKIM(dir)
o.reload = func() error { reloads++; return nil }
return o, &reloads
}
func TestEnsureKeyReusesExisting(t *testing.T) {
o, _ := newTestOpenDKIM(t)
created, err := o.EnsureKey("example.com", "selfpost")
if err != nil {
t.Fatalf("EnsureKey: %v", err)
}
if !created {
t.Fatal("expected a new key to be created")
}
first, err := os.ReadFile(o.keyPath("example.com", "selfpost"))
if err != nil {
t.Fatal(err)
}
created, err = o.EnsureKey("example.com", "selfpost")
if err != nil {
t.Fatalf("EnsureKey (second): %v", err)
}
if created {
t.Error("expected existing key to be reused, not regenerated")
}
second, _ := os.ReadFile(o.keyPath("example.com", "selfpost"))
if string(first) != string(second) {
t.Error("key file changed on reuse — published DNS record would break")
}
}
func TestRebuildWritesTablesAndReloads(t *testing.T) {
o, reloads := newTestOpenDKIM(t)
if _, err := o.EnsureKey("example.com", "selfpost"); err != nil {
t.Fatal(err)
}
if err := o.Rebuild([]SigningDomain{{Name: "example.com", Selector: "selfpost"}}); err != nil {
t.Fatalf("Rebuild: %v", err)
}
if *reloads != 1 {
t.Errorf("reload called %d times, want 1", *reloads)
}
kt, err := os.ReadFile(o.keyTablePath)
if err != nil {
t.Fatal(err)
}
if !strings.Contains(string(kt), "example.com:selfpost:") {
t.Errorf("KeyTable missing entry: %q", kt)
}
}
func TestRemoveKey(t *testing.T) {
o, _ := newTestOpenDKIM(t)
if _, err := o.EnsureKey("example.com", "selfpost"); err != nil {
t.Fatal(err)
}
if err := o.RemoveKey("example.com"); err != nil {
t.Fatalf("RemoveKey: %v", err)
}
if _, err := os.Stat(filepath.Join(o.keysDir, "example.com")); !os.IsNotExist(err) {
t.Error("key directory still present after RemoveKey")
}
// Removing a non-existent key is not an error.
if err := o.RemoveKey("example.com"); err != nil {
t.Errorf("RemoveKey on missing dir errored: %v", err)
}
}
func TestRecordFromWrittenKey(t *testing.T) {
o, _ := newTestOpenDKIM(t)
if _, err := o.EnsureKey("example.com", "selfpost"); err != nil {
t.Fatal(err)
}
rec, err := o.Record("example.com", "selfpost")
if err != nil {
t.Fatalf("Record: %v", err)
}
if rec.Name != "selfpost._domainkey.example.com" {
t.Errorf("record name = %q", rec.Name)
}
if !strings.HasPrefix(rec.Value, "v=DKIM1;") {
t.Errorf("record value = %q", rec.Value)
}
}
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package domain
import (
"fmt"
"codeberg.org/mix/selfpost/internal/store"
)
// Service coordinates the three places a sending domain lives: the SQLite
// registry, the on-disk DKIM keys and OpenDKIM's tables. Callers (the web
// handlers) validate user input first; Service keeps the three stores in
// agreement and drives the OpenDKIM reload (spec 6, 7.2.2-4, 7.2.10).
type Service struct {
store *store.Store
odk *OpenDKIM
selector string
}
// NewService builds the domain service. selectorDefault is the DKIM selector
// assigned to new domains (spec 8: DKIM_SELECTOR_DEFAULT); it is
// operator-configured, not user input.
func NewService(st *store.Store, odk *OpenDKIM, selectorDefault string) *Service {
return &Service{store: st, odk: odk, selector: selectorDefault}
}
// List returns all domains with application counts (spec 7.2.2).
func (s *Service) List() ([]store.Domain, error) {
return s.store.ListDomains()
}
// Get returns one domain by id (store.ErrDomainNotFound if absent).
func (s *Service) Get(id int64) (store.Domain, error) {
return s.store.GetDomain(id)
}
// Add registers a new sending domain: it records the row, ensures a DKIM key
// exists on disk, and regenerates + reloads the OpenDKIM tables (spec 7.2.3).
// name must already be normalised and validated by the caller. A duplicate
// returns store.ErrDomainExists.
//
// The registry row is written first so its UNIQUE constraint is the single
// arbiter of "already exists" (avoiding a check-then-act race). An existing
// on-disk key is reused rather than overwritten, so re-adding a domain whose DB
// row was lost keeps its published DNS record valid. If key generation or the
// OpenDKIM rebuild fails, the row is rolled back so we never leave a registered
// domain that OpenDKIM cannot sign.
func (s *Service) Add(name string) (store.Domain, error) {
d, err := s.store.AddDomain(name, s.selector)
if err != nil {
return store.Domain{}, err
}
if _, err := s.odk.EnsureKey(d.Name, d.DKIMSelector); err != nil {
s.rollbackAdd(d.ID)
return store.Domain{}, err
}
if err := s.resync(); err != nil {
s.rollbackAdd(d.ID)
return store.Domain{}, err
}
return d, nil
}
// rollbackAdd best-effort removes a half-created domain after a downstream
// failure. Errors here are logged by the caller's returned error path; the key
// (if freshly generated) is left in place harmlessly and reused on retry.
func (s *Service) rollbackAdd(id int64) {
_ = s.store.DeleteDomain(id)
}
// Delete removes a domain and everything bound to it — applications and their
// SASL/binding rows go via the DB cascade, and the DKIM key and table entries
// are removed here (spec 7.2.4, 6.5). The registry row and tables are updated
// (so OpenDKIM stops signing for the domain) before the key is deleted.
func (s *Service) Delete(id int64) error {
d, err := s.store.GetDomain(id)
if err != nil {
return err
}
if err := s.store.DeleteDomain(id); err != nil {
return err
}
if err := s.resync(); err != nil {
return err
}
if err := s.odk.RemoveKey(d.Name); err != nil {
// The domain is gone from the registry and tables; a leftover key
// directory is harmless. Surface it so it is not silently ignored.
return fmt.Errorf("domain deleted but key cleanup failed: %w", err)
}
return nil
}
// DKIMRecord returns the DNS TXT record to publish for a domain (spec 7.2.10).
func (s *Service) DKIMRecord(d store.Domain) (DKIMRecord, error) {
return s.odk.Record(d.Name, d.DKIMSelector)
}
// Resync regenerates the OpenDKIM tables from the registry and reloads OpenDKIM.
// It backs the manual reload button (spec 7.2.12) and doubles as a recovery path
// if the tables ever drift from the database.
func (s *Service) Resync() error {
return s.resync()
}
// resync rebuilds KeyTable/SigningTable from the current domain set and reloads.
func (s *Service) resync() error {
domains, err := s.store.ListDomains()
if err != nil {
return err
}
signing := make([]SigningDomain, 0, len(domains))
for _, d := range domains {
signing = append(signing, SigningDomain{Name: d.Name, Selector: d.DKIMSelector})
}
return s.odk.Rebuild(signing)
}