1package mox

3import (

4 "bytes"

5 "context"

6 "crypto"

7 "crypto/ecdsa"

8 "crypto/ed25519"

9 "crypto/elliptic"

10 cryptorand "crypto/rand"

11 "crypto/rsa"

12 "crypto/tls"

13 "crypto/x509"

14 "encoding/base64"

15 "encoding/pem"

16 "errors"

17 "fmt"

18 "io"

19 "log/slog"

20 "net"

21 "net/http"

22 "net/url"

23 "os"

24 "os/user"

25 "path/filepath"

26 "regexp"

27 "slices"

28 "sort"

29 "strconv"

30 "strings"

31 "sync"

32 "time"

34 "golang.org/x/text/unicode/norm"

36 "github.com/mjl-/autocert"

38 "github.com/mjl-/sconf"

40 "github.com/mjl-/mox/autotls"

41 "github.com/mjl-/mox/config"

42 "github.com/mjl-/mox/dkim"

43 "github.com/mjl-/mox/dns"

44 "github.com/mjl-/mox/message"

45 "github.com/mjl-/mox/mlog"

46 "github.com/mjl-/mox/moxio"

47 "github.com/mjl-/mox/mtasts"

48 "github.com/mjl-/mox/smtp"

49)

51var pkglog = mlog.New("mox", nil)

53// Pedantic enables stricter parsing.

54var Pedantic bool

56// Config paths are set early in program startup. They will point to files in

57// the same directory.

58var (

59 ConfigStaticPath string

60 ConfigDynamicPath string

61 Conf = Config{Log: map[string]slog.Level{"": slog.LevelError}}

62)

64var ErrConfig = errors.New("config error")

66// Set by packages webadmin, webaccount, webmail, webapisrv to prevent cyclic dependencies.

67var NewWebadminHandler = func(basePath string, isForwarded bool) http.Handler { return nopHandler }

68var NewWebaccountHandler = func(basePath string, isForwarded bool) http.Handler { return nopHandler }

69var NewWebmailHandler = func(maxMsgSize int64, basePath string, isForwarded bool, accountPath string) http.Handler {

70 return nopHandler

71}

72var NewWebapiHandler = func(maxMsgSize int64, basePath string, isForwarded bool) http.Handler { return nopHandler }

74var nopHandler = http.HandlerFunc(nil)

76// Config as used in the code, a processed version of what is in the config file.

77//

78// Use methods to lookup a domain/account/address in the dynamic configuration.

79type Config struct {

80 Static config.Static // Does not change during the lifetime of a running instance.

82 logMutex sync.Mutex // For accessing the log levels.

83 Log map[string]slog.Level

85 dynamicMutex sync.Mutex

86 Dynamic config.Dynamic // Can only be accessed directly by tests. Use methods on Config for locked access.

87 dynamicMtime time.Time

88 DynamicLastCheck time.Time // For use by quickstart only to skip checks.

89 // From canonical full address (localpart@domain, lower-cased when

90 // case-insensitive, stripped of catchall separator) to account and address.

91 // Domains are IDNA names in utf8.

92 accountDestinations map[string]AccountDestination

93 // Like accountDestinations, but for aliases.

94 aliases map[string]config.Alias

95}

97type AccountDestination struct {

98 Catchall bool // If catchall destination for its domain.

99 Localpart smtp.Localpart // In original casing as written in config file.

100 Account string

101 Destination config.Destination

102}

103

104// LogLevelSet sets a new log level for pkg. An empty pkg sets the default log

105// value that is used if no explicit log level is configured for a package.

106// This change is ephemeral, no config file is changed.

107func (c *Config) LogLevelSet(log mlog.Log, pkg string, level slog.Level) {

108 c.logMutex.Lock()

109 defer c.logMutex.Unlock()

110 l := c.copyLogLevels()

111 l[pkg] = level

112 c.Log = l

113 log.Print("log level changed", slog.String("pkg", pkg), slog.Any("level", mlog.LevelStrings[level]))

114 mlog.SetConfig(c.Log)

115}

116

117// LogLevelRemove removes a configured log level for a package.

118func (c *Config) LogLevelRemove(log mlog.Log, pkg string) {

119 c.logMutex.Lock()

120 defer c.logMutex.Unlock()

121 l := c.copyLogLevels()

122 delete(l, pkg)

123 c.Log = l

124 log.Print("log level cleared", slog.String("pkg", pkg))

125 mlog.SetConfig(c.Log)

126}

127

128// copyLogLevels returns a copy of c.Log, for modifications.

129// must be called with log lock held.

130func (c *Config) copyLogLevels() map[string]slog.Level {

131 m := map[string]slog.Level{}

132 for pkg, level := range c.Log {

133 m[pkg] = level

134 }

135 return m

136}

137

138// LogLevels returns a copy of the current log levels.

139func (c *Config) LogLevels() map[string]slog.Level {

140 c.logMutex.Lock()

141 defer c.logMutex.Unlock()

142 return c.copyLogLevels()

143}

144

145func (c *Config) withDynamicLock(fn func()) {

146 c.dynamicMutex.Lock()

147 defer c.dynamicMutex.Unlock()

148 now := time.Now()

149 if now.Sub(c.DynamicLastCheck) > time.Second {

150 c.DynamicLastCheck = now

151 if fi, err := os.Stat(ConfigDynamicPath); err != nil {

152 pkglog.Errorx("stat domains config", err)

153 } else if !fi.ModTime().Equal(c.dynamicMtime) {

154 if errs := c.loadDynamic(); len(errs) > 0 {

155 pkglog.Errorx("loading domains config", errs[0], slog.Any("errors", errs))

156 } else {

157 pkglog.Info("domains config reloaded")

158 c.dynamicMtime = fi.ModTime()

159 }

160 }

161 }

162 fn()

163}

164

165// must be called with dynamic lock held.

166func (c *Config) loadDynamic() []error {

167 d, mtime, accDests, aliases, err := ParseDynamicConfig(context.Background(), pkglog, ConfigDynamicPath, c.Static)

168 if err != nil {

169 return err

170 }

171 c.Dynamic = d

172 c.dynamicMtime = mtime

173 c.accountDestinations = accDests

174 c.aliases = aliases

175 c.allowACMEHosts(pkglog, true)

176 return nil

177}

178

179// DynamicConfig returns a shallow copy of the dynamic config. Must not be modified.

180func (c *Config) DynamicConfig() (config config.Dynamic) {

181 c.withDynamicLock(func() {

182 config = c.Dynamic // Shallow copy.

183 })

184 return

185}

186

187func (c *Config) Domains() (l []string) {

188 c.withDynamicLock(func() {

189 for name := range c.Dynamic.Domains {

190 l = append(l, name)

191 }

192 })

193 sort.Slice(l, func(i, j int) bool {

194 return l[i] < l[j]

195 })

196 return l

197}

198

199func (c *Config) Accounts() (l []string) {

200 c.withDynamicLock(func() {

201 for name := range c.Dynamic.Accounts {

202 l = append(l, name)

203 }

204 })

205 return

206}

207

208// DomainLocalparts returns a mapping of encoded localparts to account names for a

209// domain, and encoded localparts to aliases. An empty localpart is a catchall

210// destination for a domain.

211func (c *Config) DomainLocalparts(d dns.Domain) (map[string]string, map[string]config.Alias) {

212 suffix := "@" + d.Name()

213 m := map[string]string{}

214 aliases := map[string]config.Alias{}

215 c.withDynamicLock(func() {

216 for addr, ad := range c.accountDestinations {

217 if strings.HasSuffix(addr, suffix) {

218 if ad.Catchall {

219 m[""] = ad.Account

220 } else {

221 m[ad.Localpart.String()] = ad.Account

222 }

223 }

224 }

225 for addr, a := range c.aliases {

226 if strings.HasSuffix(addr, suffix) {

227 aliases[a.LocalpartStr] = a

228 }

229 }

230 })

231 return m, aliases

232}

233

234func (c *Config) Domain(d dns.Domain) (dom config.Domain, ok bool) {

235 c.withDynamicLock(func() {

236 dom, ok = c.Dynamic.Domains[d.Name()]

237 })

238 return

239}

240

241func (c *Config) Account(name string) (acc config.Account, ok bool) {

242 c.withDynamicLock(func() {

243 acc, ok = c.Dynamic.Accounts[name]

244 })

245 return

246}

247

248func (c *Config) AccountDestination(addr string) (accDest AccountDestination, alias *config.Alias, ok bool) {

249 c.withDynamicLock(func() {

250 accDest, ok = c.accountDestinations[addr]

251 if !ok {

252 var a config.Alias

253 a, ok = c.aliases[addr]

254 if ok {

255 alias = &a

256 }

257 }

258 })

259 return

260}

261

262func (c *Config) Routes(accountName string, domain dns.Domain) (accountRoutes, domainRoutes, globalRoutes []config.Route) {

263 c.withDynamicLock(func() {

264 acc := c.Dynamic.Accounts[accountName]

265 accountRoutes = acc.Routes

266

267 dom := c.Dynamic.Domains[domain.Name()]

268 domainRoutes = dom.Routes

269

270 globalRoutes = c.Dynamic.Routes

271 })

272 return

273}

274

275func (c *Config) IsClientSettingsDomain(d dns.Domain) (is bool) {

276 c.withDynamicLock(func() {

277 _, is = c.Dynamic.ClientSettingDomains[d]

278 })

279 return

280}

281

282func (c *Config) allowACMEHosts(log mlog.Log, checkACMEHosts bool) {

283 for _, l := range c.Static.Listeners {

284 if l.TLS == nil || l.TLS.ACME == "" {

285 continue

286 }

287

288 m := c.Static.ACME[l.TLS.ACME].Manager

289 hostnames := map[dns.Domain]struct{}{}

290

291 hostnames[c.Static.HostnameDomain] = struct{}{}

292 if l.HostnameDomain.ASCII != "" {

293 hostnames[l.HostnameDomain] = struct{}{}

294 }

295

296 for _, dom := range c.Dynamic.Domains {

297 // Do not allow TLS certificates for domains for which we only accept DMARC/TLS

298 // reports as external party.

299 if dom.ReportsOnly {

300 continue

301 }

302

303 if l.AutoconfigHTTPS.Enabled && !l.AutoconfigHTTPS.NonTLS {

304 if d, err := dns.ParseDomain("autoconfig." + dom.Domain.ASCII); err != nil {

305 log.Errorx("parsing autoconfig domain", err, slog.Any("domain", dom.Domain))

306 } else {

307 hostnames[d] = struct{}{}

308 }

309 }

310

311 if l.MTASTSHTTPS.Enabled && dom.MTASTS != nil && !l.MTASTSHTTPS.NonTLS {

312 d, err := dns.ParseDomain("mta-sts." + dom.Domain.ASCII)

313 if err != nil {

314 log.Errorx("parsing mta-sts domain", err, slog.Any("domain", dom.Domain))

315 } else {

316 hostnames[d] = struct{}{}

317 }

318 }

319

320 if dom.ClientSettingsDomain != "" {

321 hostnames[dom.ClientSettingsDNSDomain] = struct{}{}

322 }

323 }

324

325 if l.WebserverHTTPS.Enabled {

326 for from := range c.Dynamic.WebDNSDomainRedirects {

327 hostnames[from] = struct{}{}

328 }

329 for _, wh := range c.Dynamic.WebHandlers {

330 hostnames[wh.DNSDomain] = struct{}{}

331 }

332 }

333

334 public := c.Static.Listeners["public"]

335 ips := public.IPs

336 if len(public.NATIPs) > 0 {

337 ips = public.NATIPs

338 }

339 if public.IPsNATed {

340 ips = nil

341 }

342 m.SetAllowedHostnames(log, dns.StrictResolver{Pkg: "autotls", Log: log.Logger}, hostnames, ips, checkACMEHosts)

343 }

344}

345

346// todo future: write config parsing & writing code that can read a config and remembers the exact tokens including newlines and comments, and can write back a modified file. the goal is to be able to write a config file automatically (after changing fields through the ui), but not loose comments and whitespace, to still get useful diffs for storing the config in a version control system.

347

348// must be called with lock held.

349// Returns ErrConfig if the configuration is not valid.

350func writeDynamic(ctx context.Context, log mlog.Log, c config.Dynamic) error {

351 accDests, aliases, errs := prepareDynamicConfig(ctx, log, ConfigDynamicPath, Conf.Static, &c)

352 if len(errs) > 0 {

353 errstrs := make([]string, len(errs))

354 for i, err := range errs {

355 errstrs[i] = err.Error()

356 }

357 return fmt.Errorf("%w: %s", ErrConfig, strings.Join(errstrs, "; "))

358 }

359

360 var b bytes.Buffer

361 err := sconf.Write(&b, c)

362 if err != nil {

363 return err

364 }

365 f, err := os.OpenFile(ConfigDynamicPath, os.O_WRONLY, 0660)

366 if err != nil {

367 return err

368 }

369 defer func() {

370 if f != nil {

371 err := f.Close()

372 log.Check(err, "closing file after error")

373 }

374 }()

375 buf := b.Bytes()

376 if _, err := f.Write(buf); err != nil {

377 return fmt.Errorf("write domains.conf: %v", err)

378 }

379 if err := f.Truncate(int64(len(buf))); err != nil {

380 return fmt.Errorf("truncate domains.conf after write: %v", err)

381 }

382 if err := f.Sync(); err != nil {

383 return fmt.Errorf("sync domains.conf after write: %v", err)

384 }

385 if err := moxio.SyncDir(log, filepath.Dir(ConfigDynamicPath)); err != nil {

386 return fmt.Errorf("sync dir of domains.conf after write: %v", err)

387 }

388

389 fi, err := f.Stat()

390 if err != nil {

391 return fmt.Errorf("stat after writing domains.conf: %v", err)

392 }

393

394 if err := f.Close(); err != nil {

395 return fmt.Errorf("close written domains.conf: %v", err)

396 }

397 f = nil

398

399 Conf.dynamicMtime = fi.ModTime()

400 Conf.DynamicLastCheck = time.Now()

401 Conf.Dynamic = c

402 Conf.accountDestinations = accDests

403 Conf.aliases = aliases

404

405 Conf.allowACMEHosts(log, true)

406

407 return nil

408}

409

410// MustLoadConfig loads the config, quitting on errors.

411func MustLoadConfig(doLoadTLSKeyCerts, checkACMEHosts bool) {

412 errs := LoadConfig(context.Background(), pkglog, doLoadTLSKeyCerts, checkACMEHosts)

413 if len(errs) > 1 {

414 pkglog.Error("loading config file: multiple errors")

415 for _, err := range errs {

416 pkglog.Errorx("config error", err)

417 }

418 pkglog.Fatal("stopping after multiple config errors")

419 } else if len(errs) == 1 {

420 pkglog.Fatalx("loading config file", errs[0])

421 }

422}

423

424// LoadConfig attempts to parse and load a config, returning any errors

425// encountered.

426func LoadConfig(ctx context.Context, log mlog.Log, doLoadTLSKeyCerts, checkACMEHosts bool) []error {

427 Shutdown, ShutdownCancel = context.WithCancel(context.Background())

428 Context, ContextCancel = context.WithCancel(context.Background())

429

430 c, errs := ParseConfig(ctx, log, ConfigStaticPath, false, doLoadTLSKeyCerts, checkACMEHosts)

431 if len(errs) > 0 {

432 return errs

433 }

434

435 mlog.SetConfig(c.Log)

436 SetConfig(c)

437 return nil

438}

439

440// SetConfig sets a new config. Not to be used during normal operation.

441func SetConfig(c *Config) {

442 // Cannot just assign *c to Conf, it would copy the mutex.

443 Conf = Config{c.Static, sync.Mutex{}, c.Log, sync.Mutex{}, c.Dynamic, c.dynamicMtime, c.DynamicLastCheck, c.accountDestinations, c.aliases}

444

445 // If we have non-standard CA roots, use them for all HTTPS requests.

446 if Conf.Static.TLS.CertPool != nil {

447 http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{

448 RootCAs: Conf.Static.TLS.CertPool,

449 }

450 }

451

452 SetPedantic(c.Static.Pedantic)

453}

454

455// Set pedantic in all packages.

456func SetPedantic(p bool) {

457 dkim.Pedantic = p

458 dns.Pedantic = p

459 message.Pedantic = p

460 smtp.Pedantic = p

461 Pedantic = p

462}

463

464// ParseConfig parses the static config at path p. If checkOnly is true, no changes

465// are made, such as registering ACME identities. If doLoadTLSKeyCerts is true,

466// the TLS KeyCerts configuration is loaded and checked. This is used during the

467// quickstart in the case the user is going to provide their own certificates.

468// If checkACMEHosts is true, the hosts allowed for acme are compared with the

469// explicitly configured ips we are listening on.

470func ParseConfig(ctx context.Context, log mlog.Log, p string, checkOnly, doLoadTLSKeyCerts, checkACMEHosts bool) (c *Config, errs []error) {

471 c = &Config{

472 Static: config.Static{

473 DataDir: ".",

474 },

475 }

476

477 f, err := os.Open(p)

478 if err != nil {

479 if os.IsNotExist(err) && os.Getenv("MOXCONF") == "" {

480 return nil, []error{fmt.Errorf("open config file: %v (hint: use mox -config ... or set MOXCONF=...)", err)}

481 }

482 return nil, []error{fmt.Errorf("open config file: %v", err)}

483 }

484 defer f.Close()

485 if err := sconf.Parse(f, &c.Static); err != nil {

486 return nil, []error{fmt.Errorf("parsing %s%v", p, err)}

487 }

488

489 if xerrs := PrepareStaticConfig(ctx, log, p, c, checkOnly, doLoadTLSKeyCerts); len(xerrs) > 0 {

490 return nil, xerrs

491 }

492

493 pp := filepath.Join(filepath.Dir(p), "domains.conf")

494 c.Dynamic, c.dynamicMtime, c.accountDestinations, c.aliases, errs = ParseDynamicConfig(ctx, log, pp, c.Static)

495

496 if !checkOnly {

497 c.allowACMEHosts(log, checkACMEHosts)

498 }

499

500 return c, errs

501}

502

503// PrepareStaticConfig parses the static config file and prepares data structures

504// for starting mox. If checkOnly is set no substantial changes are made, like

505// creating an ACME registration.

506func PrepareStaticConfig(ctx context.Context, log mlog.Log, configFile string, conf *Config, checkOnly, doLoadTLSKeyCerts bool) (errs []error) {

507 addErrorf := func(format string, args ...any) {

508 errs = append(errs, fmt.Errorf(format, args...))

509 }

510

511 c := &conf.Static

512

513 // check that mailbox is in unicode NFC normalized form.

514 checkMailboxNormf := func(mailbox string, format string, args ...any) {

515 s := norm.NFC.String(mailbox)

516 if mailbox != s {

517 msg := fmt.Sprintf(format, args...)

518 addErrorf("%s: mailbox %q is not in NFC normalized form, should be %q", msg, mailbox, s)

519 }

520 }

521

522 // Post-process logging config.

523 if logLevel, ok := mlog.Levels[c.LogLevel]; ok {

524 conf.Log = map[string]slog.Level{"": logLevel}

525 } else {

526 addErrorf("invalid log level %q", c.LogLevel)

527 }

528 for pkg, s := range c.PackageLogLevels {

529 if logLevel, ok := mlog.Levels[s]; ok {

530 conf.Log[pkg] = logLevel

531 } else {

532 addErrorf("invalid package log level %q", s)

533 }

534 }

535

536 if c.User == "" {

537 c.User = "mox"

538 }

539 u, err := user.Lookup(c.User)

540 if err != nil {

541 uid, err := strconv.ParseUint(c.User, 10, 32)

542 if err != nil {

543 addErrorf("parsing unknown user %s as uid: %v (hint: add user mox with \"useradd -d $PWD mox\" or specify a different username on the quickstart command-line)", c.User, err)

544 } else {

545 // We assume the same gid as uid.

546 c.UID = uint32(uid)

547 c.GID = uint32(uid)

548 }

549 } else {

550 if uid, err := strconv.ParseUint(u.Uid, 10, 32); err != nil {

551 addErrorf("parsing uid %s: %v", u.Uid, err)

552 } else {

553 c.UID = uint32(uid)

554 }

555 if gid, err := strconv.ParseUint(u.Gid, 10, 32); err != nil {

556 addErrorf("parsing gid %s: %v", u.Gid, err)

557 } else {

558 c.GID = uint32(gid)

559 }

560 }

561

562 hostname, err := dns.ParseDomain(c.Hostname)

563 if err != nil {

564 addErrorf("parsing hostname: %s", err)

565 } else if hostname.Name() != c.Hostname {

566 addErrorf("hostname must be in unicode form %q instead of %q", hostname.Name(), c.Hostname)

567 }

568 c.HostnameDomain = hostname

569

570 if c.HostTLSRPT.Account != "" {

571 tlsrptLocalpart, err := smtp.ParseLocalpart(c.HostTLSRPT.Localpart)

572 if err != nil {

573 addErrorf("invalid localpart %q for host tlsrpt: %v", c.HostTLSRPT.Localpart, err)

574 } else if tlsrptLocalpart.IsInternational() {

575 // Does not appear documented in ../rfc/8460, but similar to DMARC it makes sense

576 // to keep this ascii-only addresses.

577 addErrorf("host TLSRPT localpart %q is an internationalized address, only conventional ascii-only address allowed for interopability", tlsrptLocalpart)

578 }

579 c.HostTLSRPT.ParsedLocalpart = tlsrptLocalpart

580 }

581

582 // Return private key for host name for use with an ACME. Used to return the same

583 // private key as pre-generated for use with DANE, with its public key in DNS.

584 // We only use this key for Listener's that have this ACME configured, and for

585 // which the effective listener host name (either specific to the listener, or the

586 // global name) is requested. Other host names can get a fresh private key, they

587 // don't appear in DANE records.

588 //

589 // - run 0: only use listener with explicitly matching host name in listener

590 // (default quickstart config does not set it).

591 // - run 1: only look at public listener (and host matching mox host name)

592 // - run 2: all listeners (and host matching mox host name)

593 findACMEHostPrivateKey := func(acmeName, host string, keyType autocert.KeyType, run int) crypto.Signer {

594 for listenerName, l := range Conf.Static.Listeners {

595 if l.TLS == nil || l.TLS.ACME != acmeName {

596 continue

597 }

598 if run == 0 && host != l.HostnameDomain.ASCII {

599 continue

600 }

601 if run == 1 && listenerName != "public" || host != Conf.Static.HostnameDomain.ASCII {

602 continue

603 }

604 switch keyType {

605 case autocert.KeyRSA2048:

606 if len(l.TLS.HostPrivateRSA2048Keys) == 0 {

607 continue

608 }

609 return l.TLS.HostPrivateRSA2048Keys[0]

610 case autocert.KeyECDSAP256:

611 if len(l.TLS.HostPrivateECDSAP256Keys) == 0 {

612 continue

613 }

614 return l.TLS.HostPrivateECDSAP256Keys[0]

615 default:

616 return nil

617 }

618 }

619 return nil

620 }

621 // Make a function for an autocert.Manager.GetPrivateKey, using findACMEHostPrivateKey.

622 makeGetPrivateKey := func(acmeName string) func(host string, keyType autocert.KeyType) (crypto.Signer, error) {

623 return func(host string, keyType autocert.KeyType) (crypto.Signer, error) {

624 key := findACMEHostPrivateKey(acmeName, host, keyType, 0)

625 if key == nil {

626 key = findACMEHostPrivateKey(acmeName, host, keyType, 1)

627 }

628 if key == nil {

629 key = findACMEHostPrivateKey(acmeName, host, keyType, 2)

630 }

631 if key != nil {

632 log.Debug("found existing private key for certificate for host",

633 slog.String("acmename", acmeName),

634 slog.String("host", host),

635 slog.Any("keytype", keyType))

636 return key, nil

637 }

638 log.Debug("generating new private key for certificate for host",

639 slog.String("acmename", acmeName),

640 slog.String("host", host),

641 slog.Any("keytype", keyType))

642 switch keyType {

643 case autocert.KeyRSA2048:

644 return rsa.GenerateKey(cryptorand.Reader, 2048)

645 case autocert.KeyECDSAP256:

646 return ecdsa.GenerateKey(elliptic.P256(), cryptorand.Reader)

647 default:

648 return nil, fmt.Errorf("unrecognized requested key type %v", keyType)

649 }

650 }

651 }

652 for name, acme := range c.ACME {

653 var eabKeyID string

654 var eabKey []byte

655 if acme.ExternalAccountBinding != nil {

656 eabKeyID = acme.ExternalAccountBinding.KeyID

657 p := configDirPath(configFile, acme.ExternalAccountBinding.KeyFile)

658 buf, err := os.ReadFile(p)

659 if err != nil {

660 addErrorf("reading external account binding key for acme provider %q: %s", name, err)

661 } else {

662 dec := make([]byte, base64.RawURLEncoding.DecodedLen(len(buf)))

663 n, err := base64.RawURLEncoding.Decode(dec, buf)

664 if err != nil {

665 addErrorf("parsing external account binding key as base64 for acme provider %q: %s", name, err)

666 } else {

667 eabKey = dec[:n]

668 }

669 }

670 }

671

672 if checkOnly {

673 continue

674 }

675

676 acmeDir := dataDirPath(configFile, c.DataDir, "acme")

677 os.MkdirAll(acmeDir, 0770)

678 manager, err := autotls.Load(name, acmeDir, acme.ContactEmail, acme.DirectoryURL, eabKeyID, eabKey, makeGetPrivateKey(name), Shutdown.Done())

679 if err != nil {

680 addErrorf("loading ACME identity for %q: %s", name, err)

681 }

682 acme.Manager = manager

683

684 // Help configurations from older quickstarts.

685 if acme.IssuerDomainName == "" && acme.DirectoryURL == "https://acme-v02.api.letsencrypt.org/directory" {

686 acme.IssuerDomainName = "letsencrypt.org"

687 }

688

689 c.ACME[name] = acme

690 }

691

692 var haveUnspecifiedSMTPListener bool

693 for name, l := range c.Listeners {

694 if l.Hostname != "" {

695 d, err := dns.ParseDomain(l.Hostname)

696 if err != nil {

697 addErrorf("bad listener hostname %q: %s", l.Hostname, err)

698 }

699 l.HostnameDomain = d

700 }

701 if l.TLS != nil {

702 if l.TLS.ACME != "" && len(l.TLS.KeyCerts) != 0 {

703 addErrorf("listener %q: cannot have ACME and static key/certificates", name)

704 } else if l.TLS.ACME != "" {

705 acme, ok := c.ACME[l.TLS.ACME]

706 if !ok {

707 addErrorf("listener %q: unknown ACME provider %q", name, l.TLS.ACME)

708 }

709

710 // If only checking or with missing ACME definition, we don't have an acme manager,

711 // so set an empty tls config to continue.

712 var tlsconfig *tls.Config

713 if checkOnly || acme.Manager == nil {

714 tlsconfig = &tls.Config{}

715 } else {

716 tlsconfig = acme.Manager.TLSConfig.Clone()

717 l.TLS.ACMEConfig = acme.Manager.ACMETLSConfig

718

719 // SMTP STARTTLS connections are commonly made without SNI, because certificates

720 // often aren't verified.

721 hostname := c.HostnameDomain

722 if l.Hostname != "" {

723 hostname = l.HostnameDomain

724 }

725 getCert := tlsconfig.GetCertificate

726 tlsconfig.GetCertificate = func(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {

727 if hello.ServerName == "" {

728 hello.ServerName = hostname.ASCII

729 }

730 return getCert(hello)

731 }

732 }

733 l.TLS.Config = tlsconfig

734 } else if len(l.TLS.KeyCerts) != 0 {

735 if doLoadTLSKeyCerts {

736 if err := loadTLSKeyCerts(configFile, "listener "+name, l.TLS); err != nil {

737 addErrorf("%w", err)

738 }

739 }

740 } else {

741 addErrorf("listener %q: cannot have TLS config without ACME and without static keys/certificates", name)

742 }

743 for _, privKeyFile := range l.TLS.HostPrivateKeyFiles {

744 keyPath := configDirPath(configFile, privKeyFile)

745 privKey, err := loadPrivateKeyFile(keyPath)

746 if err != nil {

747 addErrorf("listener %q: parsing host private key for DANE and ACME certificates: %v", name, err)

748 continue

749 }

750 switch k := privKey.(type) {

751 case *rsa.PrivateKey:

752 if k.N.BitLen() != 2048 {

753 log.Error("need rsa key with 2048 bits, for host private key for DANE/ACME certificates, ignoring",

754 slog.String("listener", name),

755 slog.String("file", keyPath),

756 slog.Int("bits", k.N.BitLen()))

757 continue

758 }

759 l.TLS.HostPrivateRSA2048Keys = append(l.TLS.HostPrivateRSA2048Keys, k)

760 case *ecdsa.PrivateKey:

761 if k.Curve != elliptic.P256() {

762 log.Error("unrecognized ecdsa curve for host private key for DANE/ACME certificates, ignoring", slog.String("listener", name), slog.String("file", keyPath))

763 continue

764 }

765 l.TLS.HostPrivateECDSAP256Keys = append(l.TLS.HostPrivateECDSAP256Keys, k)

766 default:

767 log.Error("unrecognized key type for host private key for DANE/ACME certificates, ignoring",

768 slog.String("listener", name),

769 slog.String("file", keyPath),

770 slog.String("keytype", fmt.Sprintf("%T", privKey)))

771 continue

772 }

773 }

774 if l.TLS.ACME != "" && (len(l.TLS.HostPrivateRSA2048Keys) == 0) != (len(l.TLS.HostPrivateECDSAP256Keys) == 0) {

775 log.Error("warning: uncommon configuration with either only an RSA 2048 or ECDSA P256 host private key for DANE/ACME certificates; this ACME implementation can retrieve certificates for both type of keys, it is recommended to set either both or none; continuing")

776 }

777

778 // TLS 1.2 was introduced in 2008. TLS <1.2 was deprecated by ../rfc/8996:31 and ../rfc/8997:66 in 2021.

779 var minVersion uint16 = tls.VersionTLS12

780 if l.TLS.MinVersion != "" {

781 versions := map[string]uint16{

782 "TLSv1.0": tls.VersionTLS10,

783 "TLSv1.1": tls.VersionTLS11,

784 "TLSv1.2": tls.VersionTLS12,

785 "TLSv1.3": tls.VersionTLS13,

786 }

787 v, ok := versions[l.TLS.MinVersion]

788 if !ok {

789 addErrorf("listener %q: unknown TLS mininum version %q", name, l.TLS.MinVersion)

790 }

791 minVersion = v

792 }

793 if l.TLS.Config != nil {

794 l.TLS.Config.MinVersion = minVersion

795 }

796 if l.TLS.ACMEConfig != nil {

797 l.TLS.ACMEConfig.MinVersion = minVersion

798 }

799 } else {

800 var needsTLS []string

801 needtls := func(s string, v bool) {

802 if v {

803 needsTLS = append(needsTLS, s)

804 }

805 }

806 needtls("IMAPS", l.IMAPS.Enabled)

807 needtls("SMTP", l.SMTP.Enabled && !l.SMTP.NoSTARTTLS)

808 needtls("Submissions", l.Submissions.Enabled)

809 needtls("Submission", l.Submission.Enabled && !l.Submission.NoRequireSTARTTLS)

810 needtls("AccountHTTPS", l.AccountHTTPS.Enabled)

811 needtls("AdminHTTPS", l.AdminHTTPS.Enabled)

812 needtls("AutoconfigHTTPS", l.AutoconfigHTTPS.Enabled && !l.AutoconfigHTTPS.NonTLS)

813 needtls("MTASTSHTTPS", l.MTASTSHTTPS.Enabled && !l.MTASTSHTTPS.NonTLS)

814 needtls("WebserverHTTPS", l.WebserverHTTPS.Enabled)

815 if len(needsTLS) > 0 {

816 addErrorf("listener %q does not specify tls config, but requires tls for %s", name, strings.Join(needsTLS, ", "))

817 }

818 }

819 if l.AutoconfigHTTPS.Enabled && l.MTASTSHTTPS.Enabled && l.AutoconfigHTTPS.Port == l.MTASTSHTTPS.Port && l.AutoconfigHTTPS.NonTLS != l.MTASTSHTTPS.NonTLS {

820 addErrorf("listener %q tries to enable autoconfig and mta-sts enabled on same port but with both http and https", name)

821 }

822 if l.SMTP.Enabled {

823 if len(l.IPs) == 0 {

824 haveUnspecifiedSMTPListener = true

825 }

826 for _, ipstr := range l.IPs {

827 ip := net.ParseIP(ipstr)

828 if ip == nil {

829 addErrorf("listener %q has invalid IP %q", name, ipstr)

830 continue

831 }

832 if ip.IsUnspecified() {

833 haveUnspecifiedSMTPListener = true

834 break

835 }

836 if len(c.SpecifiedSMTPListenIPs) >= 2 {

837 haveUnspecifiedSMTPListener = true

838 } else if len(c.SpecifiedSMTPListenIPs) > 0 && (c.SpecifiedSMTPListenIPs[0].To4() == nil) == (ip.To4() == nil) {

839 haveUnspecifiedSMTPListener = true

840 } else {

841 c.SpecifiedSMTPListenIPs = append(c.SpecifiedSMTPListenIPs, ip)

842 }

843 }

844 }

845 for _, s := range l.SMTP.DNSBLs {

846 d, err := dns.ParseDomain(s)

847 if err != nil {

848 addErrorf("listener %q has invalid DNSBL zone %q", name, s)

849 continue

850 }

851 l.SMTP.DNSBLZones = append(l.SMTP.DNSBLZones, d)

852 }

853 if l.IPsNATed && len(l.NATIPs) > 0 {

854 addErrorf("listener %q has both IPsNATed and NATIPs (remove deprecated IPsNATed)", name)

855 }

856 for _, ipstr := range l.NATIPs {

857 ip := net.ParseIP(ipstr)

858 if ip == nil {

859 addErrorf("listener %q has invalid ip %q", name, ipstr)

860 } else if ip.IsUnspecified() || ip.IsLoopback() {

861 addErrorf("listener %q has NAT ip that is the unspecified or loopback address %s", name, ipstr)

862 }

863 }

864 checkPath := func(kind string, enabled bool, path string) {

865 if enabled && path != "" && !strings.HasPrefix(path, "/") {

866 addErrorf("listener %q has %s with path %q that must start with a slash", name, kind, path)

867 }

868 }

869 checkPath("AccountHTTP", l.AccountHTTP.Enabled, l.AccountHTTP.Path)

870 checkPath("AccountHTTPS", l.AccountHTTPS.Enabled, l.AccountHTTPS.Path)

871 checkPath("AdminHTTP", l.AdminHTTP.Enabled, l.AdminHTTP.Path)

872 checkPath("AdminHTTPS", l.AdminHTTPS.Enabled, l.AdminHTTPS.Path)

873 c.Listeners[name] = l

874 }

875 if haveUnspecifiedSMTPListener {

876 c.SpecifiedSMTPListenIPs = nil

877 }

878

879 var zerouse config.SpecialUseMailboxes

880 if len(c.DefaultMailboxes) > 0 && (c.InitialMailboxes.SpecialUse != zerouse || len(c.InitialMailboxes.Regular) > 0) {

881 addErrorf("cannot have both DefaultMailboxes and InitialMailboxes")

882 }

883 // DefaultMailboxes is deprecated.

884 for _, mb := range c.DefaultMailboxes {

885 checkMailboxNormf(mb, "default mailbox")

886 }

887 checkSpecialUseMailbox := func(nameOpt string) {

888 if nameOpt != "" {

889 checkMailboxNormf(nameOpt, "special-use initial mailbox")

890 if strings.EqualFold(nameOpt, "inbox") {

891 addErrorf("initial mailbox cannot be set to Inbox (Inbox is always created)")

892 }

893 }

894 }

895 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Archive)

896 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Draft)

897 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Junk)

898 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Sent)

899 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Trash)

900 for _, name := range c.InitialMailboxes.Regular {

901 checkMailboxNormf(name, "regular initial mailbox")

902 if strings.EqualFold(name, "inbox") {

903 addErrorf("initial regular mailbox cannot be set to Inbox (Inbox is always created)")

904 }

905 }

906

907 checkTransportSMTP := func(name string, isTLS bool, t *config.TransportSMTP) {

908 var err error

909 t.DNSHost, err = dns.ParseDomain(t.Host)

910 if err != nil {

911 addErrorf("transport %s: bad host %s: %v", name, t.Host, err)

912 }

913

914 if isTLS && t.STARTTLSInsecureSkipVerify {

915 addErrorf("transport %s: cannot have STARTTLSInsecureSkipVerify with immediate TLS")

916 }

917 if isTLS && t.NoSTARTTLS {

918 addErrorf("transport %s: cannot have NoSTARTTLS with immediate TLS")

919 }

920

921 if t.Auth == nil {

922 return

923 }

924 seen := map[string]bool{}

925 for _, m := range t.Auth.Mechanisms {

926 if seen[m] {

927 addErrorf("transport %s: duplicate authentication mechanism %s", name, m)

928 }

929 seen[m] = true

930 switch m {

931 case "SCRAM-SHA-256-PLUS":

932 case "SCRAM-SHA-256":

933 case "SCRAM-SHA-1-PLUS":

934 case "SCRAM-SHA-1":

935 case "CRAM-MD5":

936 case "PLAIN":

937 default:

938 addErrorf("transport %s: unknown authentication mechanism %s", name, m)

939 }

940 }

941

942 t.Auth.EffectiveMechanisms = t.Auth.Mechanisms

943 if len(t.Auth.EffectiveMechanisms) == 0 {

944 t.Auth.EffectiveMechanisms = []string{"SCRAM-SHA-256-PLUS", "SCRAM-SHA-256", "SCRAM-SHA-1-PLUS", "SCRAM-SHA-1", "CRAM-MD5"}

945 }

946 }

947

948 checkTransportSocks := func(name string, t *config.TransportSocks) {

949 _, _, err := net.SplitHostPort(t.Address)

950 if err != nil {

951 addErrorf("transport %s: bad address %s: %v", name, t.Address, err)

952 }

953 for _, ipstr := range t.RemoteIPs {

954 ip := net.ParseIP(ipstr)

955 if ip == nil {

956 addErrorf("transport %s: bad ip %s", name, ipstr)

957 } else {

958 t.IPs = append(t.IPs, ip)

959 }

960 }

961 t.Hostname, err = dns.ParseDomain(t.RemoteHostname)

962 if err != nil {

963 addErrorf("transport %s: bad hostname %s: %v", name, t.RemoteHostname, err)

964 }

965 }

966

967 checkTransportDirect := func(name string, t *config.TransportDirect) {

968 if t.DisableIPv4 && t.DisableIPv6 {

969 addErrorf("transport %s: both IPv4 and IPv6 are disabled, enable at least one", name)

970 }

971 t.IPFamily = "ip"

972 if t.DisableIPv4 {

973 t.IPFamily = "ip6"

974 }

975 if t.DisableIPv6 {

976 t.IPFamily = "ip4"

977 }

978 }

979

980 for name, t := range c.Transports {

981 n := 0

982 if t.Submissions != nil {

983 n++

984 checkTransportSMTP(name, true, t.Submissions)

985 }

986 if t.Submission != nil {

987 n++

988 checkTransportSMTP(name, false, t.Submission)

989 }

990 if t.SMTP != nil {

991 n++

992 checkTransportSMTP(name, false, t.SMTP)

993 }

994 if t.Socks != nil {

995 n++

996 checkTransportSocks(name, t.Socks)

997 }

998 if t.Direct != nil {

999 n++

1000 checkTransportDirect(name, t.Direct)

1001 }

1002 if n > 1 {

1003 addErrorf("transport %s: cannot have multiple methods in a transport", name)

1004 }

1005 }

1006

1007 // Load CA certificate pool.

1008 if c.TLS.CA != nil {

1009 if c.TLS.CA.AdditionalToSystem {

1010 var err error

1011 c.TLS.CertPool, err = x509.SystemCertPool()

1012 if err != nil {

1013 addErrorf("fetching system CA cert pool: %v", err)

1014 }

1015 } else {

1016 c.TLS.CertPool = x509.NewCertPool()

1017 }

1018 for _, certfile := range c.TLS.CA.CertFiles {

1019 p := configDirPath(configFile, certfile)

1020 pemBuf, err := os.ReadFile(p)

1021 if err != nil {

1022 addErrorf("reading TLS CA cert file: %v", err)

1023 continue

1024 } else if !c.TLS.CertPool.AppendCertsFromPEM(pemBuf) {

1025 // todo: can we check more fully if we're getting some useful data back?

1026 addErrorf("no CA certs added from %q", p)

1027 }

1028 }

1029 }

1030 return

1031}

1032

1033// PrepareDynamicConfig parses the dynamic config file given a static file.

1034func ParseDynamicConfig(ctx context.Context, log mlog.Log, dynamicPath string, static config.Static) (c config.Dynamic, mtime time.Time, accDests map[string]AccountDestination, aliases map[string]config.Alias, errs []error) {

1035 addErrorf := func(format string, args ...any) {

1036 errs = append(errs, fmt.Errorf(format, args...))

1037 }

1038

1039 f, err := os.Open(dynamicPath)

1040 if err != nil {

1041 addErrorf("parsing domains config: %v", err)

1042 return

1043 }

1044 defer f.Close()

1045 fi, err := f.Stat()

1046 if err != nil {

1047 addErrorf("stat domains config: %v", err)

1048 }

1049 if err := sconf.Parse(f, &c); err != nil {

1050 addErrorf("parsing dynamic config file: %v", err)

1051 return

1052 }

1053

1054 accDests, aliases, errs = prepareDynamicConfig(ctx, log, dynamicPath, static, &c)

1055 return c, fi.ModTime(), accDests, aliases, errs

1056}

1057

1058func prepareDynamicConfig(ctx context.Context, log mlog.Log, dynamicPath string, static config.Static, c *config.Dynamic) (accDests map[string]AccountDestination, aliases map[string]config.Alias, errs []error) {

1059 addErrorf := func(format string, args ...any) {

1060 errs = append(errs, fmt.Errorf(format, args...))

1061 }

1062

1063 // Check that mailbox is in unicode NFC normalized form.

1064 checkMailboxNormf := func(mailbox string, format string, args ...any) {

1065 s := norm.NFC.String(mailbox)

1066 if mailbox != s {

1067 msg := fmt.Sprintf(format, args...)

1068 addErrorf("%s: mailbox %q is not in NFC normalized form, should be %q", msg, mailbox, s)

1069 }

1070 }

1071

1072 // Validate postmaster account exists.

1073 if _, ok := c.Accounts[static.Postmaster.Account]; !ok {

1074 addErrorf("postmaster account %q does not exist", static.Postmaster.Account)

1075 }

1076 checkMailboxNormf(static.Postmaster.Mailbox, "postmaster mailbox")

1077

1078 accDests = map[string]AccountDestination{}

1079 aliases = map[string]config.Alias{}

1080

1081 // Validate host TLSRPT account/address.

1082 if static.HostTLSRPT.Account != "" {

1083 if _, ok := c.Accounts[static.HostTLSRPT.Account]; !ok {

1084 addErrorf("host tlsrpt account %q does not exist", static.HostTLSRPT.Account)

1085 }

1086 checkMailboxNormf(static.HostTLSRPT.Mailbox, "host tlsrpt mailbox")

1087

1088 // Localpart has been parsed already.

1089

1090 addrFull := smtp.NewAddress(static.HostTLSRPT.ParsedLocalpart, static.HostnameDomain).String()

1091 dest := config.Destination{

1092 Mailbox: static.HostTLSRPT.Mailbox,

1093 HostTLSReports: true,

1094 }

1095 accDests[addrFull] = AccountDestination{false, static.HostTLSRPT.ParsedLocalpart, static.HostTLSRPT.Account, dest}

1096 }

1097

1098 var haveSTSListener, haveWebserverListener bool

1099 for _, l := range static.Listeners {

1100 if l.MTASTSHTTPS.Enabled {

1101 haveSTSListener = true

1102 }

1103 if l.WebserverHTTP.Enabled || l.WebserverHTTPS.Enabled {

1104 haveWebserverListener = true

1105 }

1106 }

1107

1108 checkRoutes := func(descr string, routes []config.Route) {

1109 parseRouteDomains := func(l []string) []string {

1110 var r []string

1111 for _, e := range l {

1112 if e == "." {

1113 r = append(r, e)

1114 continue

1115 }

1116 prefix := ""

1117 if strings.HasPrefix(e, ".") {

1118 prefix = "."

1119 e = e[1:]

1120 }

1121 d, err := dns.ParseDomain(e)

1122 if err != nil {

1123 addErrorf("%s: invalid domain %s: %v", descr, e, err)

1124 }

1125 r = append(r, prefix+d.ASCII)

1126 }

1127 return r

1128 }

1129

1130 for i := range routes {

1131 routes[i].FromDomainASCII = parseRouteDomains(routes[i].FromDomain)

1132 routes[i].ToDomainASCII = parseRouteDomains(routes[i].ToDomain)

1133 var ok bool

1134 routes[i].ResolvedTransport, ok = static.Transports[routes[i].Transport]

1135 if !ok {

1136 addErrorf("%s: route references undefined transport %s", descr, routes[i].Transport)

1137 }

1138 }

1139 }

1140

1141 checkRoutes("global routes", c.Routes)

1142

1143 // Validate domains.

1144 c.ClientSettingDomains = map[dns.Domain]struct{}{}

1145 for d, domain := range c.Domains {

1146 dnsdomain, err := dns.ParseDomain(d)

1147 if err != nil {

1148 addErrorf("bad domain %q: %s", d, err)

1149 } else if dnsdomain.Name() != d {

1150 addErrorf("domain %s must be specified in unicode form, %s", d, dnsdomain.Name())

1151 }

1152

1153 domain.Domain = dnsdomain

1154

1155 if domain.ClientSettingsDomain != "" {

1156 csd, err := dns.ParseDomain(domain.ClientSettingsDomain)

1157 if err != nil {

1158 addErrorf("bad client settings domain %q: %s", domain.ClientSettingsDomain, err)

1159 }

1160 domain.ClientSettingsDNSDomain = csd

1161 c.ClientSettingDomains[csd] = struct{}{}

1162 }

1163

1164 for _, sign := range domain.DKIM.Sign {

1165 if _, ok := domain.DKIM.Selectors[sign]; !ok {

1166 addErrorf("selector %s for signing is missing in domain %s", sign, d)

1167 }

1168 }

1169 for name, sel := range domain.DKIM.Selectors {

1170 seld, err := dns.ParseDomain(name)

1171 if err != nil {

1172 addErrorf("bad selector %q: %s", name, err)

1173 } else if seld.Name() != name {

1174 addErrorf("selector %q must be specified in unicode form, %q", name, seld.Name())

1175 }

1176 sel.Domain = seld

1177

1178 if sel.Expiration != "" {

1179 exp, err := time.ParseDuration(sel.Expiration)

1180 if err != nil {

1181 addErrorf("selector %q has invalid expiration %q: %v", name, sel.Expiration, err)

1182 } else {

1183 sel.ExpirationSeconds = int(exp / time.Second)

1184 }

1185 }

1186

1187 sel.HashEffective = sel.Hash

1188 switch sel.HashEffective {

1189 case "":

1190 sel.HashEffective = "sha256"

1191 case "sha1":

1192 log.Error("using sha1 with DKIM is deprecated as not secure enough, switch to sha256")

1193 case "sha256":

1194 default:

1195 addErrorf("unsupported hash %q for selector %q in domain %s", sel.HashEffective, name, d)

1196 }

1197

1198 pemBuf, err := os.ReadFile(configDirPath(dynamicPath, sel.PrivateKeyFile))

1199 if err != nil {

1200 addErrorf("reading private key for selector %s in domain %s: %s", name, d, err)

1201 continue

1202 }

1203 p, _ := pem.Decode(pemBuf)

1204 if p == nil {

1205 addErrorf("private key for selector %s in domain %s has no PEM block", name, d)

1206 continue

1207 }

1208 key, err := x509.ParsePKCS8PrivateKey(p.Bytes)

1209 if err != nil {

1210 addErrorf("parsing private key for selector %s in domain %s: %s", name, d, err)

1211 continue

1212 }

1213 switch k := key.(type) {

1214 case *rsa.PrivateKey:

1215 if k.N.BitLen() < 1024 {

1216 // ../rfc/6376:757

1217 // Let's help user do the right thing.

1218 addErrorf("rsa keys should be >= 1024 bits")

1219 }

1220 sel.Key = k

1221 sel.Algorithm = fmt.Sprintf("rsa-%d", k.N.BitLen())

1222 case ed25519.PrivateKey:

1223 if sel.HashEffective != "sha256" {

1224 addErrorf("hash algorithm %q is not supported with ed25519, only sha256 is", sel.HashEffective)

1225 }

1226 sel.Key = k

1227 sel.Algorithm = "ed25519"

1228 default:

1229 addErrorf("private key type %T not yet supported, at selector %s in domain %s", key, name, d)

1230 }

1231

1232 if len(sel.Headers) == 0 {

1233 // ../rfc/6376:2139

1234 // ../rfc/6376:2203

1235 // ../rfc/6376:2212

1236 // By default we seal signed headers, and we sign user-visible headers to

1237 // prevent/limit reuse of previously signed messages: All addressing fields, date

1238 // and subject, message-referencing fields, parsing instructions (content-type).

1239 sel.HeadersEffective = strings.Split("From,To,Cc,Bcc,Reply-To,References,In-Reply-To,Subject,Date,Message-Id,Content-Type", ",")

1240 } else {

1241 var from bool

1242 for _, h := range sel.Headers {

1243 from = from || strings.EqualFold(h, "From")

1244 // ../rfc/6376:2269

1245 if strings.EqualFold(h, "DKIM-Signature") || strings.EqualFold(h, "Received") || strings.EqualFold(h, "Return-Path") {

1246 log.Error("DKIM-signing header %q is recommended against as it may be modified in transit")

1247 }

1248 }

1249 if !from {

1250 addErrorf("From-field must always be DKIM-signed")

1251 }

1252 sel.HeadersEffective = sel.Headers

1253 }

1254

1255 domain.DKIM.Selectors[name] = sel

1256 }

1257

1258 if domain.MTASTS != nil {

1259 if !haveSTSListener {

1260 addErrorf("MTA-STS enabled for domain %q, but there is no listener for MTASTS", d)

1261 }

1262 sts := domain.MTASTS

1263 if sts.PolicyID == "" {

1264 addErrorf("invalid empty MTA-STS PolicyID")

1265 }

1266 switch sts.Mode {

1267 case mtasts.ModeNone, mtasts.ModeTesting, mtasts.ModeEnforce:

1268 default:

1269 addErrorf("invalid mtasts mode %q", sts.Mode)

1270 }

1271 }

1272

1273 checkRoutes("routes for domain", domain.Routes)

1274

1275 c.Domains[d] = domain

1276 }

1277

1278 // To determine ReportsOnly.

1279 domainHasAddress := map[string]bool{}

1280

1281 // Validate email addresses.

1282 for accName, acc := range c.Accounts {

1283 var err error

1284 acc.DNSDomain, err = dns.ParseDomain(acc.Domain)

1285 if err != nil {

1286 addErrorf("parsing domain %s for account %q: %s", acc.Domain, accName, err)

1287 }

1288

1289 if strings.EqualFold(acc.RejectsMailbox, "Inbox") {

1290 addErrorf("account %q: cannot set RejectsMailbox to inbox, messages will be removed automatically from the rejects mailbox", accName)

1291 }

1292 checkMailboxNormf(acc.RejectsMailbox, "account %q", accName)

1293

1294 if acc.AutomaticJunkFlags.JunkMailboxRegexp != "" {

1295 r, err := regexp.Compile(acc.AutomaticJunkFlags.JunkMailboxRegexp)

1296 if err != nil {

1297 addErrorf("invalid JunkMailboxRegexp regular expression: %v", err)

1298 }

1299 acc.JunkMailbox = r

1300 }

1301 if acc.AutomaticJunkFlags.NeutralMailboxRegexp != "" {

1302 r, err := regexp.Compile(acc.AutomaticJunkFlags.NeutralMailboxRegexp)

1303 if err != nil {

1304 addErrorf("invalid NeutralMailboxRegexp regular expression: %v", err)

1305 }

1306 acc.NeutralMailbox = r

1307 }

1308 if acc.AutomaticJunkFlags.NotJunkMailboxRegexp != "" {

1309 r, err := regexp.Compile(acc.AutomaticJunkFlags.NotJunkMailboxRegexp)

1310 if err != nil {

1311 addErrorf("invalid NotJunkMailboxRegexp regular expression: %v", err)

1312 }

1313 acc.NotJunkMailbox = r

1314 }

1315

1316 if acc.JunkFilter != nil {

1317 params := acc.JunkFilter.Params

1318 if params.MaxPower < 0 || params.MaxPower > 0.5 {

1319 addErrorf("junk filter MaxPower must be >= 0 and < 0.5")

1320 }

1321 if params.TopWords < 0 {

1322 addErrorf("junk filter TopWords must be >= 0")

1323 }

1324 if params.IgnoreWords < 0 || params.IgnoreWords > 0.5 {

1325 addErrorf("junk filter IgnoreWords must be >= 0 and < 0.5")

1326 }

1327 if params.RareWords < 0 {

1328 addErrorf("junk filter RareWords must be >= 0")

1329 }

1330 }

1331

1332 acc.ParsedFromIDLoginAddresses = make([]smtp.Address, len(acc.FromIDLoginAddresses))

1333 for i, s := range acc.FromIDLoginAddresses {

1334 a, err := smtp.ParseAddress(s)

1335 if err != nil {

1336 addErrorf("invalid fromid login address %q in account %q: %v", s, accName, err)

1337 }

1338 // We check later on if address belongs to account.

1339 dom, ok := c.Domains[a.Domain.Name()]

1340 if !ok {

1341 addErrorf("unknown domain in fromid login address %q for account %q", s, accName)

1342 } else if dom.LocalpartCatchallSeparator == "" {

1343 addErrorf("localpart catchall separator not configured for domain for fromid login address %q for account %q", s, accName)

1344 }

1345 acc.ParsedFromIDLoginAddresses[i] = a

1346 }

1347

1348 // Clear any previously derived state.

1349 acc.Aliases = nil

1350

1351 c.Accounts[accName] = acc

1352

1353 if acc.OutgoingWebhook != nil {

1354 u, err := url.Parse(acc.OutgoingWebhook.URL)

1355 if err == nil && (u.Scheme != "http" && u.Scheme != "https") {

1356 err = errors.New("scheme must be http or https")

1357 }

1358 if err != nil {

1359 addErrorf("parsing outgoing hook url %q in account %q: %v", acc.OutgoingWebhook.URL, accName, err)

1360 }

1361

1362 // note: outgoing hook events are in ../queue/hooks.go, ../mox-/config.go, ../queue.go and ../webapi/gendoc.sh. keep in sync.

1363 outgoingHookEvents := []string{"delivered", "suppressed", "delayed", "failed", "relayed", "expanded", "canceled", "unrecognized"}

1364 for _, e := range acc.OutgoingWebhook.Events {

1365 if !slices.Contains(outgoingHookEvents, e) {

1366 addErrorf("unknown outgoing hook event %q", e)

1367 }

1368 }

1369 }

1370 if acc.IncomingWebhook != nil {

1371 u, err := url.Parse(acc.IncomingWebhook.URL)

1372 if err == nil && (u.Scheme != "http" && u.Scheme != "https") {

1373 err = errors.New("scheme must be http or https")

1374 }

1375 if err != nil {

1376 addErrorf("parsing incoming hook url %q in account %q: %v", acc.IncomingWebhook.URL, accName, err)

1377 }

1378 }

1379

1380 // todo deprecated: only localpart as keys for Destinations, we are replacing them with full addresses. if domains.conf is written, we won't have to do this again.

1381 replaceLocalparts := map[string]string{}

1382

1383 for addrName, dest := range acc.Destinations {

1384 checkMailboxNormf(dest.Mailbox, "account %q, destination %q", accName, addrName)

1385

1386 for i, rs := range dest.Rulesets {

1387 checkMailboxNormf(rs.Mailbox, "account %q, destination %q, ruleset %d", accName, addrName, i+1)

1388

1389 n := 0

1390

1391 if rs.SMTPMailFromRegexp != "" {

1392 n++

1393 r, err := regexp.Compile(rs.SMTPMailFromRegexp)

1394 if err != nil {

1395 addErrorf("invalid SMTPMailFrom regular expression: %v", err)

1396 }

1397 c.Accounts[accName].Destinations[addrName].Rulesets[i].SMTPMailFromRegexpCompiled = r

1398 }

1399 if rs.MsgFromRegexp != "" {

1400 n++

1401 r, err := regexp.Compile(rs.MsgFromRegexp)

1402 if err != nil {

1403 addErrorf("invalid MsgFrom regular expression: %v", err)

1404 }

1405 c.Accounts[accName].Destinations[addrName].Rulesets[i].MsgFromRegexpCompiled = r

1406 }

1407 if rs.VerifiedDomain != "" {

1408 n++

1409 d, err := dns.ParseDomain(rs.VerifiedDomain)

1410 if err != nil {

1411 addErrorf("invalid VerifiedDomain: %v", err)

1412 }

1413 c.Accounts[accName].Destinations[addrName].Rulesets[i].VerifiedDNSDomain = d

1414 }

1415

1416 var hdr [][2]*regexp.Regexp

1417 for k, v := range rs.HeadersRegexp {

1418 n++

1419 if strings.ToLower(k) != k {

1420 addErrorf("header field %q must only have lower case characters", k)

1421 }

1422 if strings.ToLower(v) != v {

1423 addErrorf("header value %q must only have lower case characters", v)

1424 }

1425 rk, err := regexp.Compile(k)

1426 if err != nil {

1427 addErrorf("invalid rule header regexp %q: %v", k, err)

1428 }

1429 rv, err := regexp.Compile(v)

1430 if err != nil {

1431 addErrorf("invalid rule header regexp %q: %v", v, err)

1432 }

1433 hdr = append(hdr, [...]*regexp.Regexp{rk, rv})

1434 }

1435 c.Accounts[accName].Destinations[addrName].Rulesets[i].HeadersRegexpCompiled = hdr

1436

1437 if n == 0 {

1438 addErrorf("ruleset must have at least one rule")

1439 }

1440

1441 if rs.IsForward && rs.ListAllowDomain != "" {

1442 addErrorf("ruleset cannot have both IsForward and ListAllowDomain")

1443 }

1444 if rs.IsForward {

1445 if rs.SMTPMailFromRegexp == "" || rs.VerifiedDomain == "" {

1446 addErrorf("ruleset with IsForward must have both SMTPMailFromRegexp and VerifiedDomain too")

1447 }

1448 }

1449 if rs.ListAllowDomain != "" {

1450 d, err := dns.ParseDomain(rs.ListAllowDomain)

1451 if err != nil {

1452 addErrorf("invalid ListAllowDomain %q: %v", rs.ListAllowDomain, err)

1453 }

1454 c.Accounts[accName].Destinations[addrName].Rulesets[i].ListAllowDNSDomain = d

1455 }

1456

1457 checkMailboxNormf(rs.AcceptRejectsToMailbox, "account %q, destination %q, ruleset %d, rejects mailbox", accName, addrName, i+1)

1458 if strings.EqualFold(rs.AcceptRejectsToMailbox, "inbox") {

1459 addErrorf("account %q, destination %q, ruleset %d: AcceptRejectsToMailbox cannot be set to Inbox", accName, addrName, i+1)

1460 }

1461 }

1462

1463 // Catchall destination for domain.

1464 if strings.HasPrefix(addrName, "@") {

1465 d, err := dns.ParseDomain(addrName[1:])

1466 if err != nil {

1467 addErrorf("parsing domain %q in account %q", addrName[1:], accName)

1468 continue

1469 } else if _, ok := c.Domains[d.Name()]; !ok {

1470 addErrorf("unknown domain for address %q in account %q", addrName, accName)

1471 continue

1472 }

1473 domainHasAddress[d.Name()] = true

1474 addrFull := "@" + d.Name()

1475 if _, ok := accDests[addrFull]; ok {

1476 addErrorf("duplicate canonicalized catchall destination address %s", addrFull)

1477 }

1478 accDests[addrFull] = AccountDestination{true, "", accName, dest}

1479 continue

1480 }

1481

1482 // todo deprecated: remove support for parsing destination as just a localpart instead full address.

1483 var address smtp.Address

1484 if localpart, err := smtp.ParseLocalpart(addrName); err != nil && errors.Is(err, smtp.ErrBadLocalpart) {

1485 address, err = smtp.ParseAddress(addrName)

1486 if err != nil {

1487 addErrorf("invalid email address %q in account %q", addrName, accName)

1488 continue

1489 } else if _, ok := c.Domains[address.Domain.Name()]; !ok {

1490 addErrorf("unknown domain for address %q in account %q", addrName, accName)

1491 continue

1492 }

1493 } else {

1494 if err != nil {

1495 addErrorf("invalid localpart %q in account %q", addrName, accName)

1496 continue

1497 }

1498 address = smtp.NewAddress(localpart, acc.DNSDomain)

1499 if _, ok := c.Domains[acc.DNSDomain.Name()]; !ok {

1500 addErrorf("unknown domain %s for account %q", acc.DNSDomain.Name(), accName)

1501 continue

1502 }

1503 replaceLocalparts[addrName] = address.Pack(true)

1504 }

1505

1506 origLP := address.Localpart

1507 dc := c.Domains[address.Domain.Name()]

1508 domainHasAddress[address.Domain.Name()] = true

1509 lp := CanonicalLocalpart(address.Localpart, dc)

1510 if dc.LocalpartCatchallSeparator != "" && strings.Contains(string(address.Localpart), dc.LocalpartCatchallSeparator) {

1511 addErrorf("localpart of address %s includes domain catchall separator %s", address, dc.LocalpartCatchallSeparator)

1512 } else {

1513 address.Localpart = lp

1514 }

1515 addrFull := address.Pack(true)

1516 if _, ok := accDests[addrFull]; ok {

1517 addErrorf("duplicate canonicalized destination address %s", addrFull)

1518 }

1519 accDests[addrFull] = AccountDestination{false, origLP, accName, dest}

1520 }

1521

1522 for lp, addr := range replaceLocalparts {

1523 dest, ok := acc.Destinations[lp]

1524 if !ok {

1525 addErrorf("could not find localpart %q to replace with address in destinations", lp)

1526 } else {

1527 log.Warn(`deprecation warning: support for account destination addresses specified as just localpart ("username") instead of full email address will be removed in the future; update domains.conf, for each Account, for each Destination, ensure each key is an email address by appending "@" and the default domain for the account`,

1528 slog.Any("localpart", lp),

1529 slog.Any("address", addr),

1530 slog.String("account", accName))

1531 acc.Destinations[addr] = dest

1532 delete(acc.Destinations, lp)

1533 }

1534 }

1535

1536 // Now that all addresses are parsed, check if all fromid login addresses match

1537 // configured addresses.

1538 for i, a := range acc.ParsedFromIDLoginAddresses {

1539 // For domain catchall.