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 "strconv"

29 "strings"

30 "sync"

31 "time"

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

35 "github.com/mjl-/autocert"

37 "github.com/mjl-/sconf"

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

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

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

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

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

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

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

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

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

48)

50var pkglog = mlog.New("mox", nil)

52// Pedantic enables stricter parsing.

53var Pedantic bool

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

56// the same directory.

57var (

58 ConfigStaticPath string

59 ConfigDynamicPath string

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

61)

63var ErrConfig = errors.New("config error")

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

66var NewWebadminHandler = func(basePath string, isForwarded bool) http.Handler { return nopHandler }

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

68var NewWebmailHandler = func(maxMsgSize int64, basePath string, isForwarded bool, accountPath string) http.Handler {

69 return nopHandler

70}

71var NewWebapiHandler = func(maxMsgSize int64, basePath string, isForwarded bool) http.Handler { return nopHandler }

73var nopHandler = http.HandlerFunc(nil)

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

76//

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

78type Config struct {

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

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

82 Log map[string]slog.Level

84 dynamicMutex sync.Mutex

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

86 dynamicMtime time.Time

87 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. Dynamic config lock must be held when accessing.

92 AccountDestinationsLocked map[string]AccountDestination

94 // Like AccountDestinationsLocked, but for aliases.

95 aliases map[string]config.Alias

96}

98type AccountDestination struct {

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

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

101 Account string

102 Destination config.Destination

103}

104

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

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

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

108func (c *Config) LogLevelSet(log mlog.Log, pkg string, level slog.Level) {

109 c.logMutex.Lock()

110 defer c.logMutex.Unlock()

111 l := c.copyLogLevels()

112 l[pkg] = level

113 c.Log = l

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

115 mlog.SetConfig(c.Log)

116}

117

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

119func (c *Config) LogLevelRemove(log mlog.Log, pkg string) {

120 c.logMutex.Lock()

121 defer c.logMutex.Unlock()

122 l := c.copyLogLevels()

123 delete(l, pkg)

124 c.Log = l

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

126 mlog.SetConfig(c.Log)

127}

128

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

130// must be called with log lock held.

131func (c *Config) copyLogLevels() map[string]slog.Level {

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

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

134 m[pkg] = level

135 }

136 return m

137}

138

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

140func (c *Config) LogLevels() map[string]slog.Level {

141 c.logMutex.Lock()

142 defer c.logMutex.Unlock()

143 return c.copyLogLevels()

144}

145

146// DynamicLockUnlock locks the dynamic config, will try updating the latest state

147// from disk, and return an unlock function. Should be called as "defer

148// Conf.DynamicLockUnlock()()".

149func (c *Config) DynamicLockUnlock() func() {

150 c.dynamicMutex.Lock()

151 now := time.Now()

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

153 c.DynamicLastCheck = now

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

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

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

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

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

159 } else {

160 pkglog.Info("domains config reloaded")

161 c.dynamicMtime = fi.ModTime()

162 }

163 }

164 }

165 return c.dynamicMutex.Unlock

166}

167

168func (c *Config) withDynamicLock(fn func()) {

169 defer c.DynamicLockUnlock()()

170 fn()

171}

172

173// must be called with dynamic lock held.

174func (c *Config) loadDynamic() []error {

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

176 if err != nil {

177 return err

178 }

179 c.Dynamic = d

180 c.dynamicMtime = mtime

181 c.AccountDestinationsLocked = accDests

182 c.aliases = aliases

183 c.allowACMEHosts(pkglog, true)

184 return nil

185}

186

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

188func (c *Config) DynamicConfig() (config config.Dynamic) {

189 c.withDynamicLock(func() {

190 config = c.Dynamic // Shallow copy.

191 })

192 return

193}

194

195func (c *Config) Domains() (l []string) {

196 c.withDynamicLock(func() {

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

198 l = append(l, name)

199 }

200 })

201 slices.Sort(l)

202 return l

203}

204

205func (c *Config) Accounts() (l []string) {

206 c.withDynamicLock(func() {

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

208 l = append(l, name)

209 }

210 })

211 return

212}

213

214func (c *Config) AccountsDisabled() (all, disabled []string) {

215 c.withDynamicLock(func() {

216 for name, conf := range c.Dynamic.Accounts {

217 all = append(all, name)

218 if conf.LoginDisabled != "" {

219 disabled = append(disabled, name)

220 }

221 }

222 })

223 return

224}

225

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

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

228// destination for a domain.

229func (c *Config) DomainLocalparts(d dns.Domain) (map[string]string, map[string]config.Alias) {

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

231 m := map[string]string{}

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

233 c.withDynamicLock(func() {

234 for addr, ad := range c.AccountDestinationsLocked {

235 if strings.HasSuffix(addr, suffix) {

236 if ad.Catchall {

237 m[""] = ad.Account

238 } else {

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

240 }

241 }

242 }

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

244 if strings.HasSuffix(addr, suffix) {

245 aliases[a.LocalpartStr] = a

246 }

247 }

248 })

249 return m, aliases

250}

251

252func (c *Config) Domain(d dns.Domain) (dom config.Domain, ok bool) {

253 c.withDynamicLock(func() {

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

255 })

256 return

257}

258

259func (c *Config) DomainConfigs() (doms []config.Domain) {

260 c.withDynamicLock(func() {

261 doms = make([]config.Domain, 0, len(c.Dynamic.Domains))

262 for _, d := range c.Dynamic.Domains {

263 doms = append(doms, d)

264 }

265 })

266 return

267}

268

269func (c *Config) Account(name string) (acc config.Account, ok bool) {

270 c.withDynamicLock(func() {

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

272 })

273 return

274}

275

276func (c *Config) AccountDestination(addr string) (accDest AccountDestination, alias *config.Alias, ok bool) {

277 c.withDynamicLock(func() {

278 accDest, ok = c.AccountDestinationsLocked[addr]

279 if !ok {

280 var a config.Alias

281 a, ok = c.aliases[addr]

282 if ok {

283 alias = &a

284 }

285 }

286 })

287 return

288}

289

290func (c *Config) Routes(accountName string, domain dns.Domain) (accountRoutes, domainRoutes, globalRoutes []config.Route) {

291 c.withDynamicLock(func() {

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

293 accountRoutes = acc.Routes

294

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

296 domainRoutes = dom.Routes

297

298 globalRoutes = c.Dynamic.Routes

299 })

300 return

301}

302

303func (c *Config) IsClientSettingsDomain(d dns.Domain) (is bool) {

304 c.withDynamicLock(func() {

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

306 })

307 return

308}

309

310func (c *Config) allowACMEHosts(log mlog.Log, checkACMEHosts bool) {

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

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

313 continue

314 }

315

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

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

318

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

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

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

322 }

323

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

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

326 // reports as external party.

327 if dom.ReportsOnly {

328 continue

329 }

330

331 // Do not fetch TLS certs for disabled domains. The A/AAAA records may not be

332 // configured or still point to a previous machine before a migration.

333 if dom.Disabled {

334 continue

335 }

336

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

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

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

340 } else {

341 hostnames[d] = struct{}{}

342 }

343 }

344

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

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

347 if err != nil {

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

349 } else {

350 hostnames[d] = struct{}{}

351 }

352 }

353

354 if dom.ClientSettingsDomain != "" {

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

356 }

357 }

358

359 if l.WebserverHTTPS.Enabled {

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

361 hostnames[from] = struct{}{}

362 }

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

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

365 }

366 }

367

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

369 ips := public.IPs

370 if len(public.NATIPs) > 0 {

371 ips = public.NATIPs

372 }

373 if public.IPsNATed {

374 ips = nil

375 }

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

377 }

378}

379

380// 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.

381

382// WriteDynamicLocked prepares an updated internal state for the new dynamic

383// config, then writes it to disk and activates it.

384//

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

386//

387// Must be called with config lock held.

388func WriteDynamicLocked(ctx context.Context, log mlog.Log, c config.Dynamic) error {

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

390 if len(errs) > 0 {

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

392 for i, err := range errs {

393 errstrs[i] = err.Error()

394 }

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

396 }

397

398 var b bytes.Buffer

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

400 if err != nil {

401 return err

402 }

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

404 if err != nil {

405 return err

406 }

407 defer func() {

408 if f != nil {

409 err := f.Close()

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

411 }

412 }()

413 buf := b.Bytes()

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

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

416 }

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

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

419 }

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

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

422 }

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

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

425 }

426

427 fi, err := f.Stat()

428 if err != nil {

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

430 }

431

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

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

434 }

435 f = nil

436

437 Conf.dynamicMtime = fi.ModTime()

438 Conf.DynamicLastCheck = time.Now()

439 Conf.Dynamic = c

440 Conf.AccountDestinationsLocked = accDests

441 Conf.aliases = aliases

442

443 Conf.allowACMEHosts(log, true)

444

445 return nil

446}

447

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

449func MustLoadConfig(doLoadTLSKeyCerts, checkACMEHosts bool) {

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

451 if len(errs) > 1 {

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

453 for _, err := range errs {

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

455 }

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

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

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

459 }

460}

461

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

463// encountered.

464func LoadConfig(ctx context.Context, log mlog.Log, doLoadTLSKeyCerts, checkACMEHosts bool) []error {

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

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

467

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

469 if len(errs) > 0 {

470 return errs

471 }

472

473 mlog.SetConfig(c.Log)

474 SetConfig(c)

475 return nil

476}

477

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

479func SetConfig(c *Config) {

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

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

482

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

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

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

486 RootCAs: Conf.Static.TLS.CertPool,

487 }

488 }

489

490 SetPedantic(c.Static.Pedantic)

491}

492

493// Set pedantic in all packages.

494func SetPedantic(p bool) {

495 dkim.Pedantic = p

496 dns.Pedantic = p

497 message.Pedantic = p

498 smtp.Pedantic = p

499 Pedantic = p

500}

501

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

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

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

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

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

507// explicitly configured ips we are listening on.

508func ParseConfig(ctx context.Context, log mlog.Log, p string, checkOnly, doLoadTLSKeyCerts, checkACMEHosts bool) (c *Config, errs []error) {

509 c = &Config{

510 Static: config.Static{

511 DataDir: ".",

512 },

513 }

514

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

516 if err != nil {

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

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

519 }

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

521 }

522 defer f.Close()

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

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

525 }

526

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

528 return nil, xerrs

529 }

530

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

532 c.Dynamic, c.dynamicMtime, c.AccountDestinationsLocked, c.aliases, errs = ParseDynamicConfig(ctx, log, pp, c.Static)

533

534 if !checkOnly {

535 c.allowACMEHosts(log, checkACMEHosts)

536 }

537

538 return c, errs

539}

540

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

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

543// creating an ACME registration.

544func PrepareStaticConfig(ctx context.Context, log mlog.Log, configFile string, conf *Config, checkOnly, doLoadTLSKeyCerts bool) (errs []error) {

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

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

547 }

548

549 c := &conf.Static

550

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

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

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

554 if mailbox != s {

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

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

557 }

558 }

559

560 // Post-process logging config.

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

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

563 } else {

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

565 }

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

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

568 conf.Log[pkg] = logLevel

569 } else {

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

571 }

572 }

573

574 if c.User == "" {

575 c.User = "mox"

576 }

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

578 if err != nil {

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

580 if err != nil {

581 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)

582 } else {

583 // We assume the same gid as uid.

584 c.UID = uint32(uid)

585 c.GID = uint32(uid)

586 }

587 } else {

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

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

590 } else {

591 c.UID = uint32(uid)

592 }

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

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

595 } else {

596 c.GID = uint32(gid)

597 }

598 }

599

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

601 if err != nil {

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

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

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

605 }

606 c.HostnameDomain = hostname

607

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

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

610 if err != nil {

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

612 } else if tlsrptLocalpart.IsInternational() {

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

614 // to keep this ascii-only addresses.

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

616 }

617 c.HostTLSRPT.ParsedLocalpart = tlsrptLocalpart

618 }

619

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

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

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

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

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

625 // don't appear in DANE records.

626 //

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

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

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

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

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

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

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

634 continue

635 }

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

637 continue

638 }

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

640 continue

641 }

642 switch keyType {

643 case autocert.KeyRSA2048:

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

645 continue

646 }

647 return l.TLS.HostPrivateRSA2048Keys[0]

648 case autocert.KeyECDSAP256:

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

650 continue

651 }

652 return l.TLS.HostPrivateECDSAP256Keys[0]

653 default:

654 return nil

655 }

656 }

657 return nil

658 }

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

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

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

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

663 if key == nil {

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

665 }

666 if key == nil {

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

668 }

669 if key != nil {

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

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

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

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

674 return key, nil

675 }

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

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

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

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

680 switch keyType {

681 case autocert.KeyRSA2048:

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

683 case autocert.KeyECDSAP256:

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

685 default:

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

687 }

688 }

689 }

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

691 addAcmeErrorf := func(format string, args ...any) {

692 addErrorf("acme provider %s: %s", name, fmt.Sprintf(format, args...))

693 }

694

695 var eabKeyID string

696 var eabKey []byte

697 if acme.ExternalAccountBinding != nil {

698 eabKeyID = acme.ExternalAccountBinding.KeyID

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

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

701 if err != nil {

702 addAcmeErrorf("reading external account binding key: %s", err)

703 } else {

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

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

706 if err != nil {

707 addAcmeErrorf("parsing external account binding key as base64: %s", err)

708 } else {

709 eabKey = dec[:n]

710 }

711 }

712 }

713

714 if checkOnly {

715 continue

716 }

717

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

719 os.MkdirAll(acmeDir, 0770)

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

721 if err != nil {

722 addAcmeErrorf("loading ACME identity: %s", err)

723 }

724 acme.Manager = manager

725

726 // Help configurations from older quickstarts.

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

728 acme.IssuerDomainName = "letsencrypt.org"

729 }

730

731 c.ACME[name] = acme

732 }

733

734 var haveUnspecifiedSMTPListener bool

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

736 addListenerErrorf := func(format string, args ...any) {

737 addErrorf("listener %s: %s", name, fmt.Sprintf(format, args...))

738 }

739

740 if l.Hostname != "" {

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

742 if err != nil {

743 addListenerErrorf("parsing hostname %q: %s", l.Hostname, err)

744 }

745 l.HostnameDomain = d

746 }

747 if l.TLS != nil {

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

749 addListenerErrorf("cannot have ACME and static key/certificates")

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

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

752 if !ok {

753 addListenerErrorf("unknown ACME provider %q", l.TLS.ACME)

754 }

755

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

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

758 var tlsconfig, tlsconfigFallback *tls.Config

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

760 tlsconfig = &tls.Config{}

761 tlsconfigFallback = &tls.Config{}

762 } else {

763 hostname := c.HostnameDomain

764 if l.Hostname != "" {

765 hostname = l.HostnameDomain

766 }

767 // If SNI is absent, we will use the listener hostname, but reject connections with

768 // an SNI hostname that is not allowlisted.

769 // Incoming SMTP deliveries use tlsconfigFallback for interoperability. TLS

770 // connections for unknown SNI hostnames fall back to a certificate for the

771 // listener hostname instead of causing the TLS connection to fail.

772 tlsconfig = acme.Manager.TLSConfig(hostname, true, false)

773 tlsconfigFallback = acme.Manager.TLSConfig(hostname, true, true)

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

775 }

776 l.TLS.Config = tlsconfig

777 l.TLS.ConfigFallback = tlsconfigFallback

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

779 if doLoadTLSKeyCerts {

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

781 addListenerErrorf("%w", err)

782 }

783 }

784 } else {

785 addListenerErrorf("cannot have TLS config without ACME and without static keys/certificates")

786 }

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

788 keyPath := configDirPath(configFile, privKeyFile)

789 privKey, err := loadPrivateKeyFile(keyPath)

790 if err != nil {

791 addListenerErrorf("parsing host private key for DANE and ACME certificates: %v", err)

792 continue

793 }

794 switch k := privKey.(type) {

795 case *rsa.PrivateKey:

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

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

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

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

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

801 continue

802 }

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

804 case *ecdsa.PrivateKey:

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

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

807 continue

808 }

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

810 default:

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

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

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

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

815 continue

816 }

817 }

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

819 log.Warn("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")

820 }

821

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

823 var minVersion uint16 = tls.VersionTLS12

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

825 versions := map[string]uint16{

826 "TLSv1.0": tls.VersionTLS10,

827 "TLSv1.1": tls.VersionTLS11,

828 "TLSv1.2": tls.VersionTLS12,

829 "TLSv1.3": tls.VersionTLS13,

830 }

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

832 if !ok {

833 addListenerErrorf("unknown TLS mininum version %q", l.TLS.MinVersion)

834 }

835 minVersion = v

836 }

837 if l.TLS.Config != nil {

838 l.TLS.Config.MinVersion = minVersion

839 }

840 if l.TLS.ConfigFallback != nil {

841 l.TLS.ConfigFallback.MinVersion = minVersion

842 }

843 if l.TLS.ACMEConfig != nil {

844 l.TLS.ACMEConfig.MinVersion = minVersion

845 }

846 } else {

847 var needsTLS []string

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

849 if v {

850 needsTLS = append(needsTLS, s)

851 }

852 }

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

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

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

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

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

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

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

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

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

862 if len(needsTLS) > 0 {

863 addListenerErrorf("no tls config specified, but requires tls for %s", strings.Join(needsTLS, ", "))

864 }

865 }

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

867 addListenerErrorf("autoconfig and mta-sts enabled on same port but with both http and https")

868 }

869 if l.SMTP.Enabled {

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

871 haveUnspecifiedSMTPListener = true

872 }

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

874 ip := net.ParseIP(ipstr)

875 if ip == nil {

876 addListenerErrorf("invalid IP %q", ipstr)

877 continue

878 }

879 if ip.IsUnspecified() {

880 haveUnspecifiedSMTPListener = true

881 break

882 }

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

884 haveUnspecifiedSMTPListener = true

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

886 haveUnspecifiedSMTPListener = true

887 } else {

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

889 }

890 }

891 }

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

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

894 if err != nil {

895 addListenerErrorf("parsing DNSBL zone %q: %s", s, err)

896 continue

897 }

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

899 }

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

901 addListenerErrorf("both IPsNATed and NATIPs configued (remove deprecated IPsNATed)")

902 }

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

904 ip := net.ParseIP(ipstr)

905 if ip == nil {

906 addListenerErrorf("invalid ip %q", ipstr)

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

908 addListenerErrorf("NAT ip that is the unspecified or loopback address %s", ipstr)

909 }

910 }

911 cleanPath := func(kind string, enabled bool, path string) string {

912 if !enabled {

913 return path

914 }

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

916 addListenerErrorf("%s with path %q that must start with a slash", kind, path)

917 } else if path != "" && !strings.HasSuffix(path, "/") {

918 log.Warn("http service path should end with a slash, using effective path with slash", slog.String("kind", kind), slog.String("path", path), slog.String("effectivepath", path+"/"))

919 path += "/"

920 }

921 return path

922 }

923 l.AccountHTTP.Path = cleanPath("AccountHTTP", l.AccountHTTP.Enabled, l.AccountHTTP.Path)

924 l.AccountHTTPS.Path = cleanPath("AccountHTTPS", l.AccountHTTPS.Enabled, l.AccountHTTPS.Path)

925 l.AdminHTTP.Path = cleanPath("AdminHTTP", l.AdminHTTP.Enabled, l.AdminHTTP.Path)

926 l.AdminHTTPS.Path = cleanPath("AdminHTTPS", l.AdminHTTPS.Enabled, l.AdminHTTPS.Path)

927 l.WebmailHTTP.Path = cleanPath("WebmailHTTP", l.WebmailHTTP.Enabled, l.WebmailHTTP.Path)

928 l.WebmailHTTPS.Path = cleanPath("WebmailHTTPS", l.WebmailHTTPS.Enabled, l.WebmailHTTPS.Path)

929 l.WebAPIHTTP.Path = cleanPath("WebAPIHTTP", l.WebAPIHTTP.Enabled, l.WebAPIHTTP.Path)

930 l.WebAPIHTTPS.Path = cleanPath("WebAPIHTTPS", l.WebAPIHTTPS.Enabled, l.WebAPIHTTPS.Path)

931 c.Listeners[name] = l

932 }

933 if haveUnspecifiedSMTPListener {

934 c.SpecifiedSMTPListenIPs = nil

935 }

936

937 var zerouse config.SpecialUseMailboxes

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

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

940 }

941 // DefaultMailboxes is deprecated.

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

943 checkMailboxNormf(mb, "default mailbox")

944 // We don't create parent mailboxes for default mailboxes.

945 if ParentMailboxName(mb) != "" {

946 addErrorf("default mailbox cannot be a child mailbox")

947 }

948 }

949 checkSpecialUseMailbox := func(nameOpt string) {

950 if nameOpt != "" {

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

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

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

954 }

955 // We don't currently create parent mailboxes for initial mailboxes.

956 if ParentMailboxName(nameOpt) != "" {

957 addErrorf("initial mailboxes cannot be child mailboxes")

958 }

959 }

960 }

961 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Archive)

962 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Draft)

963 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Junk)

964 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Sent)

965 checkSpecialUseMailbox(c.InitialMailboxes.SpecialUse.Trash)

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

967 checkMailboxNormf(name, "regular initial mailbox")

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

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

970 }

971 if ParentMailboxName(name) != "" {

972 addErrorf("initial mailboxes cannot be child mailboxes")

973 }

974 }

975

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

977 addTransportErrorf := func(format string, args ...any) {

978 addErrorf("transport %s: %s", name, fmt.Sprintf(format, args...))

979 }

980

981 var err error

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

983 if err != nil {

984 addTransportErrorf("bad host %s: %v", t.Host, err)

985 }

986

987 if isTLS && t.STARTTLSInsecureSkipVerify {

988 addTransportErrorf("cannot have STARTTLSInsecureSkipVerify with immediate TLS")

989 }

990 if isTLS && t.NoSTARTTLS {

991 addTransportErrorf("cannot have NoSTARTTLS with immediate TLS")

992 }

993

994 if t.Auth == nil {

995 return

996 }

997 seen := map[string]bool{}

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

999 if seen[m] {

1000 addTransportErrorf("duplicate authentication mechanism %s", m)

1001 }

1002 seen[m] = true

1003 switch m {

1004 case "SCRAM-SHA-256-PLUS":

1005 case "SCRAM-SHA-256":

1006 case "SCRAM-SHA-1-PLUS":

1007 case "SCRAM-SHA-1":

1008 case "CRAM-MD5":

1009 case "PLAIN":

1010 default:

1011 addTransportErrorf("unknown authentication mechanism %s", m)

1012 }

1013 }

1014

1015 t.Auth.EffectiveMechanisms = t.Auth.Mechanisms

1016 if len(t.Auth.EffectiveMechanisms) == 0 {

1017 t.Auth.EffectiveMechanisms = []string{"SCRAM-SHA-256-PLUS", "SCRAM-SHA-256", "SCRAM-SHA-1-PLUS", "SCRAM-SHA-1", "CRAM-MD5"}

1018 }

1019 }

1020

1021 checkTransportSocks := func(name string, t *config.TransportSocks) {

1022 addTransportErrorf := func(format string, args ...any) {

1023 addErrorf("transport %s: %s", name, fmt.Sprintf(format, args...))

1024 }

1025

1026 _, _, err := net.SplitHostPort(t.Address)

1027 if err != nil {

1028 addTransportErrorf("bad address %s: %v", t.Address, err)

1029 }

1030 for _, ipstr := range t.RemoteIPs {

1031 ip := net.ParseIP(ipstr)

1032 if ip == nil {

1033 addTransportErrorf("bad ip %s", ipstr)

1034 } else {

1035 t.IPs = append(t.IPs, ip)

1036 }

1037 }

1038 t.Hostname, err = dns.ParseDomain(t.RemoteHostname)

1039 if err != nil {

1040 addTransportErrorf("bad hostname %s: %v", t.RemoteHostname, err)

1041 }

1042 }

1043

1044 checkTransportDirect := func(name string, t *config.TransportDirect) {

1045 addTransportErrorf := func(format string, args ...any) {

1046 addErrorf("transport %s: %s", name, fmt.Sprintf(format, args...))

1047 }

1048

1049 if t.DisableIPv4 && t.DisableIPv6 {

1050 addTransportErrorf("both IPv4 and IPv6 are disabled, enable at least one")

1051 }

1052 t.IPFamily = "ip"

1053 if t.DisableIPv4 {

1054 t.IPFamily = "ip6"

1055 }

1056 if t.DisableIPv6 {

1057 t.IPFamily = "ip4"

1058 }

1059 }

1060

1061 checkTransportFail := func(name string, t *config.TransportFail) {

1062 addTransportErrorf := func(format string, args ...any) {

1063 addErrorf("transport %s: %s", name, fmt.Sprintf(format, args...))

1064 }

1065

1066 if t.SMTPCode == 0 {

1067 t.Code = smtp.C554TransactionFailed

1068 } else if t.SMTPCode/100 != 4 && t.SMTPCode/100 != 5 {

1069 addTransportErrorf("smtp code %d must be 4xx or 5xx", t.SMTPCode/100)

1070 } else {

1071 t.Code = t.SMTPCode

1072 }

1073

1074 if len(t.SMTPMessage) > 256 {

1075 addTransportErrorf("message must be <= 256 characters")

1076 }

1077 for _, c := range t.SMTPMessage {

1078 if c < ' ' || c >= 0x7f {

1079 addTransportErrorf("message cannot contain control characters including newlines, and must be ascii-only")

1080 }

1081 }

1082 t.Message = t.SMTPMessage

1083 if t.Message == "" {

1084 t.Message = "transport fail: explicit immediate delivery failure per configuration"

1085 }

1086 }

1087

1088 for name, t := range c.Transports {

1089 addTransportErrorf := func(format string, args ...any) {

1090 addErrorf("transport %s: %s", name, fmt.Sprintf(format, args...))

1091 }

1092

1093 n := 0

1094 if t.Submissions != nil {

1095 n++

1096 checkTransportSMTP(name, true, t.Submissions)

1097 }

1098 if t.Submission != nil {

1099 n++

1100 checkTransportSMTP(name, false, t.Submission)

1101 }

1102 if t.SMTP != nil {

1103 n++

1104 checkTransportSMTP(name, false, t.SMTP)

1105 }

1106 if t.Socks != nil {

1107 n++

1108 checkTransportSocks(name, t.Socks)

1109 }

1110 if t.Direct != nil {

1111 n++

1112 checkTransportDirect(name, t.Direct)

1113 }

1114 if t.Fail != nil {

1115 n++

1116 checkTransportFail(name, t.Fail)

1117 }

1118 if n > 1 {

1119 addTransportErrorf("cannot have multiple methods in a transport")

1120 }

1121 }

1122

1123 // Load CA certificate pool.

1124 if c.TLS.CA != nil {

1125 if c.TLS.CA.AdditionalToSystem {

1126 var err error

1127 c.TLS.CertPool, err = x509.SystemCertPool()

1128 if err != nil {

1129 addErrorf("fetching system CA cert pool: %v", err)

1130 }

1131 } else {

1132 c.TLS.CertPool = x509.NewCertPool()

1133 }

1134 for _, certfile := range c.TLS.CA.CertFiles {

1135 p := configDirPath(configFile, certfile)

1136 pemBuf, err := os.ReadFile(p)

1137 if err != nil {

1138 addErrorf("reading TLS CA cert file: %v", err)

1139 continue

1140 } else if !c.TLS.CertPool.AppendCertsFromPEM(pemBuf) {

1141 // todo: can we check more fully if we're getting some useful data back?

1142 addErrorf("no CA certs added from %q", p)

1143 }

1144 }

1145 }

1146 return

1147}

1148

1149// PrepareDynamicConfig parses the dynamic config file given a static file.

1150func 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) {

1151 addErrorf := func(format string, args ...any) {

1152 errs = append(errs, fmt.Errorf(format, args...))

1153 }

1154

1155 f, err := os.Open(dynamicPath)

1156 if err != nil {

1157 addErrorf("parsing domains config: %v", err)

1158 return

1159 }

1160 defer f.Close()

1161 fi, err := f.Stat()

1162 if err != nil {

1163 addErrorf("stat domains config: %v", err)

1164 }

1165 if err := sconf.Parse(f, &c); err != nil {

1166 addErrorf("parsing dynamic config file: %v", err)

1167 return

1168 }

1169

1170 accDests, aliases, errs = prepareDynamicConfig(ctx, log, dynamicPath, static, &c)

1171 return c, fi.ModTime(), accDests, aliases, errs

1172}

1173

1174func 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) {

1175 addErrorf := func(format string, args ...any) {

1176 errs = append(errs, fmt.Errorf(format, args...))

1177 }

1178

1179 // Check that mailbox is in unicode NFC normalized form.

1180 checkMailboxNormf := func(mailbox string, what string, errorf func(format string, args ...any)) {

1181 s := norm.NFC.String(mailbox)

1182 if mailbox != s {

1183 errorf("%s: mailbox %q is not in NFC normalized form, should be %q", what, mailbox, s)

1184 }

1185 }

1186

1187 // Validate postmaster account exists.

1188 if _, ok := c.Accounts[static.Postmaster.Account]; !ok {

1189 addErrorf("postmaster account %q does not exist", static.Postmaster.Account)

1190 }

1191 checkMailboxNormf(static.Postmaster.Mailbox, "postmaster mailbox", addErrorf)

1192

1193 accDests = map[string]AccountDestination{}

1194 aliases = map[string]config.Alias{}

1195

1196 // Validate host TLSRPT account/address.

1197 if static.HostTLSRPT.Account != "" {

1198 if _, ok := c.Accounts[static.HostTLSRPT.Account]; !ok {

1199 addErrorf("host tlsrpt account %q does not exist", static.HostTLSRPT.Account)

1200 }

1201 checkMailboxNormf(static.HostTLSRPT.Mailbox, "host tlsrpt mailbox", addErrorf)

1202

1203 // Localpart has been parsed already.

1204

1205 addrFull := smtp.NewAddress(static.HostTLSRPT.ParsedLocalpart, static.HostnameDomain).String()

1206 dest := config.Destination{

1207 Mailbox: static.HostTLSRPT.Mailbox,

1208 HostTLSReports: true,

1209 }

1210 accDests[addrFull] = AccountDestination{false, static.HostTLSRPT.ParsedLocalpart, static.HostTLSRPT.Account, dest}

1211 }

1212

1213 var haveSTSListener, haveWebserverListener bool

1214 for _, l := range static.Listeners {

1215 if l.MTASTSHTTPS.Enabled {

1216 haveSTSListener = true

1217 }

1218 if l.WebserverHTTP.Enabled || l.WebserverHTTPS.Enabled {

1219 haveWebserverListener = true

1220 }

1221 }

1222

1223 checkRoutes := func(descr string, routes []config.Route) {

1224 parseRouteDomains := func(l []string) []string {

1225 var r []string

1226 for _, e := range l {

1227 if e == "." {

1228 r = append(r, e)

1229 continue

1230 }

1231 prefix := ""

1232 if strings.HasPrefix(e, ".") {

1233 prefix = "."

1234 e = e[1:]

1235 }

1236 d, err := dns.ParseDomain(e)

1237 if err != nil {

1238 addErrorf("%s: invalid domain %s: %v", descr, e, err)

1239 }

1240 r = append(r, prefix+d.ASCII)

1241 }

1242 return r

1243 }

1244

1245 for i := range routes {

1246 routes[i].FromDomainASCII = parseRouteDomains(routes[i].FromDomain)

1247 routes[i].ToDomainASCII = parseRouteDomains(routes[i].ToDomain)

1248 var ok bool

1249 routes[i].ResolvedTransport, ok = static.Transports[routes[i].Transport]

1250 if !ok {

1251 addErrorf("%s: route references undefined transport %s", descr, routes[i].Transport)

1252 }

1253 }

1254 }

1255

1256 checkRoutes("global routes", c.Routes)

1257

1258 // Validate domains.

1259 c.ClientSettingDomains = map[dns.Domain]struct{}{}

1260 for d, domain := range c.Domains {

1261 addDomainErrorf := func(format string, args ...any) {

1262 addErrorf(fmt.Sprintf("domain %v: %s", d, fmt.Sprintf(format, args...)))

1263 }

1264

1265 dnsdomain, err := dns.ParseDomain(d)

1266 if err != nil {

1267 addDomainErrorf("parsing domain: %s", err)

1268 } else if dnsdomain.Name() != d {

1269 addDomainErrorf("must be specified in unicode form, %s", dnsdomain.Name())

1270 }

1271

1272 domain.Domain = dnsdomain

1273

1274 if domain.ClientSettingsDomain != "" {

1275 csd, err := dns.ParseDomain(domain.ClientSettingsDomain)

1276 if err != nil {

1277 addDomainErrorf("bad client settings domain %q: %s", domain.ClientSettingsDomain, err)

1278 }

1279 domain.ClientSettingsDNSDomain = csd

1280 c.ClientSettingDomains[csd] = struct{}{}

1281 }

1282

1283 if domain.LocalpartCatchallSeparator != "" && len(domain.LocalpartCatchallSeparators) != 0 {

1284 addDomainErrorf("cannot have both LocalpartCatchallSeparator and LocalpartCatchallSeparators")

1285 }

1286 domain.LocalpartCatchallSeparatorsEffective = domain.LocalpartCatchallSeparators

1287 if domain.LocalpartCatchallSeparator != "" {

1288 domain.LocalpartCatchallSeparatorsEffective = append(domain.LocalpartCatchallSeparatorsEffective, domain.LocalpartCatchallSeparator)

1289 }

1290 sepSeen := map[string]bool{}

1291 for _, sep := range domain.LocalpartCatchallSeparatorsEffective {

1292 if sepSeen[sep] {

1293 addDomainErrorf("duplicate localpart catchall separator %q", sep)

1294 }

1295 sepSeen[sep] = true

1296 }

1297

1298 for _, sign := range domain.DKIM.Sign {

1299 if _, ok := domain.DKIM.Selectors[sign]; !ok {

1300 addDomainErrorf("unknown selector %s for signing", sign)

1301 }

1302 }

1303 for name, sel := range domain.DKIM.Selectors {

1304 addSelectorErrorf := func(format string, args ...any) {

1305 addDomainErrorf("selector %s: %s", name, fmt.Sprintf(format, args...))

1306 }

1307

1308 seld, err := dns.ParseDomain(name)

1309 if err != nil {

1310 addSelectorErrorf("parsing selector: %s", err)

1311 } else if seld.Name() != name {

1312 addSelectorErrorf("must be specified in unicode form, %q", seld.Name())

1313 }

1314 sel.Domain = seld

1315

1316 if sel.Expiration != "" {

1317 exp, err := time.ParseDuration(sel.Expiration)

1318 if err != nil {

1319 addSelectorErrorf("invalid expiration %q: %v", sel.Expiration, err)

1320 } else {

1321 sel.ExpirationSeconds = int(exp / time.Second)

1322 }

1323 }

1324

1325 sel.HashEffective = sel.Hash

1326 switch sel.HashEffective {

1327 case "":

1328 sel.HashEffective = "sha256"

1329 case "sha1":

1330 log.Error("using sha1 with DKIM is deprecated as not secure enough, switch to sha256")

1331 case "sha256":

1332 default:

1333 addSelectorErrorf("unsupported hash %q", sel.HashEffective)

1334 }

1335

1336 pemBuf, err := os.ReadFile(configDirPath(dynamicPath, sel.PrivateKeyFile))

1337 if err != nil {

1338 addSelectorErrorf("reading private key: %s", err)

1339 continue

1340 }

1341 p, _ := pem.Decode(pemBuf)

1342 if p == nil {

1343 addSelectorErrorf("private key has no PEM block")

1344 continue

1345 }

1346 key, err := x509.ParsePKCS8PrivateKey(p.Bytes)

1347 if err != nil {

1348 addSelectorErrorf("parsing private key: %s", err)

1349 continue

1350 }

1351 switch k := key.(type) {

1352 case *rsa.PrivateKey:

1353 if k.N.BitLen() < 1024 {

1354 // ../rfc/6376:757

1355 // Let's help user do the right thing.

1356 addSelectorErrorf("rsa keys should be >= 1024 bits, is %d bits", k.N.BitLen())

1357 }

1358 sel.Key = k

1359 sel.Algorithm = fmt.Sprintf("rsa-%d", k.N.BitLen())

1360 case ed25519.PrivateKey:

1361 if sel.HashEffective != "sha256" {

1362 addSelectorErrorf("hash algorithm %q is not supported with ed25519, only sha256 is", sel.HashEffective)

1363 }

1364 sel.Key = k

1365 sel.Algorithm = "ed25519"

1366 default:

1367 addSelectorErrorf("private key type %T not yet supported", key)

1368 }

1369

1370 if len(sel.Headers) == 0 {

1371 // ../rfc/6376:2139

1372 // ../rfc/6376:2203

1373 // ../rfc/6376:2212

1374 // By default we seal signed headers, and we sign user-visible headers to

1375 // prevent/limit reuse of previously signed messages: All addressing fields, date

1376 // and subject, message-referencing fields, parsing instructions (content-type).

1377 sel.HeadersEffective = strings.Split("From,To,Cc,Bcc,Reply-To,References,In-Reply-To,Subject,Date,Message-Id,Content-Type", ",")

1378 } else {

1379 var from bool

1380 for _, h := range sel.Headers {

1381 from = from || strings.EqualFold(h, "From")

1382 // ../rfc/6376:2269

1383 if strings.EqualFold(h, "DKIM-Signature") || strings.EqualFold(h, "Received") || strings.EqualFold(h, "Return-Path") {

1384 log.Error("DKIM-signing header %q is recommended against as it may be modified in transit")

1385 }

1386 }

1387 if !from {

1388 addSelectorErrorf("From-field must always be DKIM-signed")

1389 }

1390 sel.HeadersEffective = sel.Headers

1391 }

1392

1393 domain.DKIM.Selectors[name] = sel

1394 }

1395

1396 if domain.MTASTS != nil {

1397 if !haveSTSListener {

1398 addDomainErrorf("MTA-STS enabled, but there is no listener for MTASTS", d)

1399 }

1400 sts := domain.MTASTS

1401 if sts.PolicyID == "" {

1402 addDomainErrorf("invalid empty MTA-STS PolicyID")

1403 }

1404 switch sts.Mode {

1405 case mtasts.ModeNone, mtasts.ModeTesting, mtasts.ModeEnforce:

1406 default:

1407 addDomainErrorf("invalid mtasts mode %q", sts.Mode)

1408 }

1409 }

1410

1411 checkRoutes("routes for domain", domain.Routes)

1412

1413 c.Domains[d] = domain

1414 }

1415

1416 // To determine ReportsOnly.

1417 domainHasAddress := map[string]bool{}

1418

1419 // Validate email addresses.

1420 for accName, acc := range c.Accounts {

1421 addAccountErrorf := func(format string, args ...any) {

1422 addErrorf("account %q: %s", accName, fmt.Sprintf(format, args...))

1423 }

1424

1425 var err error

1426 acc.DNSDomain, err = dns.ParseDomain(acc.Domain)

1427 if err != nil {

1428 addAccountErrorf("parsing domain %s: %s", acc.Domain, err)

1429 }

1430

1431 if strings.EqualFold(acc.RejectsMailbox, "Inbox") {

1432 addAccountErrorf("cannot set RejectsMailbox to inbox, messages will be removed automatically from the rejects mailbox")

1433 }

1434 checkMailboxNormf(acc.RejectsMailbox, "rejects mailbox", addErrorf)

1435

1436 if len(acc.LoginDisabled) > 256 {

1437 addAccountErrorf("message for disabled login must be <256 characters")

1438 }

1439 for _, c := range acc.LoginDisabled {

1440 // For IMAP and SMTP. IMAP only allows UTF8 after "ENABLE IMAPrev2".

1441 if c < ' ' || c >= 0x7f {

1442 addAccountErrorf("message cannot contain control characters including newlines, and must be ascii-only")

1443 }

1444 }

1445

1446 if acc.AutomaticJunkFlags.JunkMailboxRegexp != "" {

1447 r, err := regexp.Compile(acc.AutomaticJunkFlags.JunkMailboxRegexp)

1448 if err != nil {

1449 addAccountErrorf("invalid JunkMailboxRegexp regular expression: %v", err)

1450 }

1451 acc.JunkMailbox = r

1452 }

1453 if acc.AutomaticJunkFlags.NeutralMailboxRegexp != "" {

1454 r, err := regexp.Compile(acc.AutomaticJunkFlags.NeutralMailboxRegexp)

1455 if err != nil {

1456 addAccountErrorf("invalid NeutralMailboxRegexp regular expression: %v", err)

1457 }

1458 acc.NeutralMailbox = r

1459 }

1460 if acc.AutomaticJunkFlags.NotJunkMailboxRegexp != "" {

1461 r, err := regexp.Compile(acc.AutomaticJunkFlags.NotJunkMailboxRegexp)

1462 if err != nil {

1463 addAccountErrorf("invalid NotJunkMailboxRegexp regular expression: %v", err)

1464 }

1465 acc.NotJunkMailbox = r

1466 }

1467

1468 if acc.JunkFilter != nil {

1469 params := acc.JunkFilter.Params

1470 if params.MaxPower < 0 || params.MaxPower > 0.5 {

1471 addAccountErrorf("junk filter MaxPower must be >= 0 and < 0.5")

1472 }

1473 if params.TopWords < 0 {

1474 addAccountErrorf("junk filter TopWords must be >= 0")

1475 }

1476 if params.IgnoreWords < 0 || params.IgnoreWords > 0.5 {

1477 addAccountErrorf("junk filter IgnoreWords must be >= 0 and < 0.5")

1478 }

1479 if params.RareWords < 0 {

1480 addAccountErrorf("junk filter RareWords must be >= 0")

1481 }

1482 }

1483

1484 acc.ParsedFromIDLoginAddresses = make([]smtp.Address, len(acc.FromIDLoginAddresses))

1485 for i, s := range acc.FromIDLoginAddresses {

1486 a, err := smtp.ParseAddress(s)

1487 if err != nil {

1488 addAccountErrorf("invalid fromid login address %q: %v", s, err)

1489 }

1490 // We check later on if address belongs to account.

1491 dom, ok := c.Domains[a.Domain.Name()]

1492 if !ok {

1493 addAccountErrorf("unknown domain in fromid login address %q", s)

1494 } else if len(dom.LocalpartCatchallSeparatorsEffective) == 0 {

1495 addAccountErrorf("localpart catchall separator not configured for domain for fromid login address %q", s)

1496 }

1497 acc.ParsedFromIDLoginAddresses[i] = a

1498 }

1499

1500 // Clear any previously derived state.

1501 acc.Aliases = nil

1502

1503 c.Accounts[accName] = acc

1504

1505 if acc.OutgoingWebhook != nil {

1506 u, err := url.Parse(acc.OutgoingWebhook.URL)

1507 if err == nil && (u.Scheme != "http" && u.Scheme != "https") {

1508 err = errors.New("scheme must be http or https")

1509 }

1510 if err != nil {

1511 addAccountErrorf("parsing outgoing hook url %q: %v", acc.OutgoingWebhook.URL, err)

1512 }

1513

1514 // note: outgoing hook events are in ../queue/hooks.go, ../mox-/config.go, ../queue.go and ../webapi/gendoc.sh. keep in sync.

1515 outgoingHookEvents := []string{"delivered", "suppressed", "delayed", "failed", "relayed", "expanded", "canceled", "unrecognized"}

1516 for _, e := range acc.OutgoingWebhook.Events {

1517 if !slices.Contains(outgoingHookEvents, e) {

1518 addAccountErrorf("unknown outgoing hook event %q", e)

1519 }

1520 }

1521 }

1522 if acc.IncomingWebhook != nil {

1523 u, err := url.Parse(acc.IncomingWebhook.URL)

1524 if err == nil && (u.Scheme != "http" && u.Scheme != "https") {

1525 err = errors.New("scheme must be http or https")

1526 }

1527 if err != nil {

1528 addAccountErrorf("parsing incoming hook url %q: %v", acc.IncomingWebhook.URL, err)

1529 }

1530 }

1531

1532 // 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.

1533 replaceLocalparts := map[string]string{}

1534

1535 for addrName, dest := range acc.Destinations {

1536 addDestErrorf := func(format string, args ...any) {

1537 addAccountErrorf("destination %q: %s", addrName, fmt.Sprintf(format, args...))

1538 }

1539

1540 checkMailboxNormf(dest.Mailbox, "destination mailbox", addDestErrorf)

1541

1542 if dest.SMTPError != "" {

1543 if len(dest.SMTPError) > 256 {

1544 addDestErrorf("smtp error must be smaller than 256 bytes")

1545 }

1546 for _, c := range dest.SMTPError {

1547 if c < ' ' || c >= 0x7f {

1548 addDestErrorf("smtp error cannot contain contain control characters (including newlines) or non-ascii")

1549 break

1550 }

1551 }

1552

1553 if dest.Mailbox != "" {

1554 addDestErrorf("cannot have both SMTPError and Mailbox")

1555 }

1556 if len(dest.Rulesets) != 0 {

1557 addDestErrorf("cannot have both SMTPError and Rulesets")

1558 }

1559

1560 t := strings.SplitN(dest.SMTPError, " ", 2)

1561 switch t[0] {

1562 default:

1563 addDestErrorf("smtp error must be 421 or 550 (with optional message), not %q", dest.SMTPError)

1564

1565 case "421":

1566 dest.SMTPErrorCode = smtp.C451LocalErr

1567 dest.SMTPErrorSecode = smtp.SeSys3Other0

1568 dest.SMTPErrorMsg = "error processing"

1569 case "550":

1570 dest.SMTPErrorCode = smtp.C550MailboxUnavail

1571 dest.SMTPErrorSecode = smtp.SeAddr1UnknownDestMailbox1

1572 dest.SMTPErrorMsg = "no such user(s)"

1573 }

1574 if len(t) > 1 {

1575 dest.SMTPErrorMsg = strings.TrimSpace(t[1])

1576 }

1577 acc.Destinations[addrName] = dest

1578 }

1579

1580 if dest.MessageAuthRequiredSMTPError != "" {

1581 if len(dest.MessageAuthRequiredSMTPError) > 256 {

1582 addDestErrorf("message authentication required smtp error must be smaller than 256 bytes")

1583 }

1584 for _, c := range dest.MessageAuthRequiredSMTPError {

1585 if c < ' ' || c >= 0x7f {

1586 addDestErrorf("message authentication required smtp error cannot contain contain control characters (including newlines) or non-ascii")

1587 break

1588 }

1589 }

1590 }

1591

1592 for i, rs := range dest.Rulesets {

1593 addRulesetErrorf := func(format string, args ...any) {

1594 addDestErrorf("ruleset %d: %s", i+1, fmt.Sprintf(format, args...))

1595 }

1596

1597 checkMailboxNormf(rs.Mailbox, "ruleset mailbox", addRulesetErrorf)

1598

1599 n := 0

1600

1601 if rs.SMTPMailFromRegexp != "" {

1602 n++

1603 r, err := regexp.Compile(rs.SMTPMailFromRegexp)

1604 if err != nil {

1605 addRulesetErrorf("invalid SMTPMailFrom regular expression: %v", err)

1606 }

1607 c.Accounts[accName].Destinations[addrName].Rulesets[i].SMTPMailFromRegexpCompiled = r

1608 }

1609 if rs.MsgFromRegexp != "" {

1610 n++

1611 r, err := regexp.Compile(rs.MsgFromRegexp)

1612 if err != nil {

1613 addRulesetErrorf("invalid MsgFrom regular expression: %v", err)

1614 }

1615 c.Accounts[accName].Destinations[addrName].Rulesets[i].MsgFromRegexpCompiled = r

1616 }

1617 if rs.VerifiedDomain != "" {

1618 n++

1619 d, err := dns.ParseDomain(rs.VerifiedDomain)

1620 if err != nil {

1621 addRulesetErrorf("invalid VerifiedDomain: %v", err)

1622 }

1623 c.Accounts[accName].Destinations[addrName].Rulesets[i].VerifiedDNSDomain = d

1624 }

1625

1626 var hdr [][2]*regexp.Regexp

1627 for k, v := range rs.HeadersRegexp {

1628 n++

1629 if strings.ToLower(k) != k {

1630 addRulesetErrorf("header field %q must only have lower case characters", k)

1631 }

1632 if strings.ToLower(v) != v {

1633 addRulesetErrorf("header value %q must only have lower case characters", v)

1634 }

1635 rk, err := regexp.Compile(k)

1636 if err != nil {

1637 addRulesetErrorf("invalid rule header regexp %q: %v", k, err)

1638 }

1639 rv, err := regexp.Compile(v)

1640 if err != nil {

1641 addRulesetErrorf("invalid rule header regexp %q: %v", v, err)

1642 }

1643 hdr = append(hdr, [...]*regexp.Regexp{rk, rv})

1644 }

1645 c.Accounts[accName].Destinations[addrName].Rulesets[i].HeadersRegexpCompiled = hdr

1646

1647 if n == 0 {

1648 addRulesetErrorf("ruleset must have at least one rule")

1649 }

1650

1651 if rs.IsForward && rs.ListAllowDomain != "" {

1652 addRulesetErrorf("ruleset cannot have both IsForward and ListAllowDomain")

1653 }

1654 if rs.IsForward {

1655 if rs.SMTPMailFromRegexp == "" || rs.VerifiedDomain == "" {

1656 addRulesetErrorf("ruleset with IsForward must have both SMTPMailFromRegexp and VerifiedDomain too")

1657 }

1658 }

1659 if rs.ListAllowDomain != "" {

1660 d, err := dns.ParseDomain(rs.ListAllowDomain)

1661 if err != nil {

1662 addRulesetErrorf("invalid ListAllowDomain %q: %v", rs.ListAllowDomain, err)

1663 }

1664 c.Accounts[accName].Destinations[addrName].Rulesets[i].ListAllowDNSDomain = d

1665 }

1666

1667 checkMailboxNormf(rs.AcceptRejectsToMailbox, "rejects mailbox", addRulesetErrorf)

1668 if strings.EqualFold(rs.AcceptRejectsToMailbox, "inbox") {

1669 addRulesetErrorf("AcceptRejectsToMailbox cannot be set to Inbox")

1670 }

1671 }

1672

1673 // Catchall destination for domain.

1674 if strings.HasPrefix(addrName, "@") {

1675 d, err := dns.ParseDomain(addrName[1:])

1676 if err != nil {

1677 addDestErrorf("parsing domain %q", addrName[1:])

1678 continue

1679 } else if _, ok := c.Domains[d.Name()]; !ok {

1680 addDestErrorf("unknown domain for address")

1681 continue

1682 }

1683 domainHasAddress[d.Name()] = true

1684 addrFull := "@" + d.Name()

1685 if _, ok := accDests[addrFull]; ok {

1686 addDestErrorf("duplicate canonicalized catchall destination address %s", addrFull)

1687 }

1688 accDests[addrFull] = AccountDestination{true, "", accName, dest}

1689 continue

1690 }

1691

1692 // todo deprecated: remove support for parsing destination as just a localpart instead full address.

1693 var address smtp.Address

1694 if localpart, err := smtp.ParseLocalpart(addrName); err != nil && errors.Is(err, smtp.ErrBadLocalpart) {

1695 address, err = smtp.ParseAddress(addrName)

1696 if err != nil {

1697 addDestErrorf("invalid email address")

1698 continue

1699 } else if _, ok := c.Domains[address.Domain.Name()]; !ok {

1700 addDestErrorf("unknown domain for address")

1701 continue

1702 }

1703 } else {

1704 if err != nil {

1705 addDestErrorf("invalid localpart %q", addrName)

1706 continue

1707 }

1708 address = smtp.NewAddress(localpart, acc.DNSDomain)

1709 if _, ok := c.Domains[acc.DNSDomain.Name()]; !ok {

1710 addDestErrorf("unknown domain %s", acc.DNSDomain.Name())

1711 continue

1712 }

1713 replaceLocalparts[addrName] = address.Pack(true)

1714 }

1715

1716 origLP := address.Localpart

1717 dc := c.Domains[address.Domain.Name()]

1718 domainHasAddress[address.Domain.Name()] = true

1719 lp := CanonicalLocalpart(address.Localpart, dc)

1720 var hasSep bool

1721 for _, sep := range dc.LocalpartCatchallSeparatorsEffective {

1722 if strings.Contains(string(address.Localpart), sep) {

1723 hasSep = true

1724 addDestErrorf("localpart of address %s includes domain catchall separator %s", address, sep)

1725 }

1726 }

1727 if !hasSep {

1728 address.Localpart = lp

1729 }

1730 addrFull := address.Pack(true)

1731 if _, ok := accDests[addrFull]; ok {

1732 addDestErrorf("duplicate canonicalized destination address %s", addrFull)

1733 }

1734 accDests[addrFull] = AccountDestination{false, origLP, accName, dest}

1735 }

1736

1737 for lp, addr := range replaceLocalparts {

1738 dest, ok := acc.Destinations[lp]

1739 if !ok {

1740 addAccountErrorf("could not find localpart %q to replace with address in destinations", lp)

1741 } else {

1742 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`,

1743 slog.Any("localpart", lp),

1744 slog.Any("address", addr),

1745 slog.String("account", accName))

1746 acc.Destinations[addr] = dest

1747 delete(acc.Destinations, lp)

1748 }

1749 }

1750

1751 // Now that all addresses are parsed, check if all fromid login addresses match

1752 // configured addresses.

1753 for i, a := range acc.ParsedFromIDLoginAddresses {

1754 // For domain catchall.