mox/http/web.go
Mechiel Lukkien cc3a2c9bc8
make it possible to serve https on a different port than 443 through configuration
so you can run mox on openbsd with port redirects in pf.conf.

in the future, starting as root, binding the sockets, and passing the bound
sockets to a new unprivileged process should be implemented, but this should
get openbsd users going.

from discussion with mteege
2023-02-18 16:53:06 +01:00

232 lines
7.6 KiB
Go

// Package http provides HTTP listeners/servers, for
// autoconfiguration/autodiscovery, the account and admin web interface and
// MTA-STS policies.
package http
import (
"crypto/tls"
"fmt"
golog "log"
"net"
"net/http"
"strings"
"time"
_ "net/http/pprof"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/mjl-/mox/config"
"github.com/mjl-/mox/dns"
"github.com/mjl-/mox/mlog"
"github.com/mjl-/mox/mox-"
)
var xlog = mlog.New("http")
// Set some http headers that should prevent potential abuse. Better safe than sorry.
func safeHeaders(fn http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
h := w.Header()
h.Set("X-Frame-Options", "deny")
h.Set("X-Content-Type-Options", "nosniff")
h.Set("Content-Security-Policy", "default-src 'self' 'unsafe-inline' data:")
h.Set("Referrer-Policy", "same-origin")
fn(w, r)
}
}
// ListenAndServe starts listeners for HTTP, including those required for ACME to
// generate TLS certificates.
func ListenAndServe() {
type serve struct {
kinds []string
tlsConfig *tls.Config
mux *http.ServeMux
}
for name, l := range mox.Conf.Static.Listeners {
portServe := map[int]serve{}
var ensureServe func(https bool, port int, kind string) serve
ensureServe = func(https bool, port int, kind string) serve {
s, ok := portServe[port]
if !ok {
s = serve{nil, nil, &http.ServeMux{}}
}
s.kinds = append(s.kinds, kind)
if https && l.TLS.ACME != "" {
s.tlsConfig = l.TLS.ACMEConfig
} else if https {
s.tlsConfig = l.TLS.Config
if l.TLS.ACME != "" {
ensureServe(true, config.Port(mox.Conf.Static.ACME[l.TLS.ACME].Port, 443), "acme-tls-alpn-01")
}
}
portServe[port] = s
return s
}
if l.SMTP.Enabled && !l.SMTP.NoSTARTTLS || l.Submissions.Enabled || l.IMAPS.Enabled {
ensureServe(true, config.Port(config.Port(l.AutoconfigHTTPS.Port, 443), 443), "acme-tls-alpn01")
}
if l.AccountHTTP.Enabled {
srv := ensureServe(false, config.Port(l.AccountHTTP.Port, 80), "account-http")
srv.mux.HandleFunc("/", safeHeaders(accountHandle))
}
if l.AccountHTTPS.Enabled {
srv := ensureServe(true, config.Port(l.AccountHTTP.Port, 443), "account-https")
srv.mux.HandleFunc("/", safeHeaders(accountHandle))
}
if l.AdminHTTP.Enabled {
srv := ensureServe(false, config.Port(l.AdminHTTP.Port, 80), "admin-http")
if !l.AccountHTTP.Enabled {
srv.mux.HandleFunc("/", safeHeaders(adminIndex))
}
srv.mux.HandleFunc("/admin/", safeHeaders(adminHandle))
}
if l.AdminHTTPS.Enabled {
srv := ensureServe(true, config.Port(l.AdminHTTPS.Port, 443), "admin-https")
if !l.AccountHTTP.Enabled {
srv.mux.HandleFunc("/", safeHeaders(adminIndex))
}
srv.mux.HandleFunc("/admin/", safeHeaders(adminHandle))
}
if l.MetricsHTTP.Enabled {
srv := ensureServe(false, config.Port(l.MetricsHTTP.Port, 8010), "metrics-http")
srv.mux.Handle("/metrics", safeHeaders(promhttp.Handler().ServeHTTP))
srv.mux.HandleFunc("/", safeHeaders(func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
} else if r.Method != "GET" {
http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
return
}
w.Header().Set("Content-Type", "text/html")
fmt.Fprint(w, `<html><body>see <a href="/metrics">/metrics</a></body></html>`)
}))
}
if l.AutoconfigHTTPS.Enabled {
srv := ensureServe(true, config.Port(l.AutoconfigHTTPS.Port, 443), "autoconfig-https")
srv.mux.HandleFunc("/mail/config-v1.1.xml", safeHeaders(autoconfHandle(l)))
srv.mux.HandleFunc("/autodiscover/autodiscover.xml", safeHeaders(autodiscoverHandle(l)))
}
if l.MTASTSHTTPS.Enabled {
srv := ensureServe(true, config.Port(l.MTASTSHTTPS.Port, 443), "mtasts-https")
srv.mux.HandleFunc("/.well-known/mta-sts.txt", safeHeaders(mtastsPolicyHandle))
}
if l.PprofHTTP.Enabled {
// Importing net/http/pprof registers handlers on the default serve mux.
port := config.Port(l.PprofHTTP.Port, 8011)
if _, ok := portServe[port]; ok {
xlog.Fatal("cannot serve pprof on same endpoint as other http services")
}
portServe[port] = serve{[]string{"pprof-http"}, nil, http.DefaultServeMux}
}
// We'll explicitly ensure these TLS certs exist (e.g. are created with ACME)
// immediately after startup. We only do so for our explicitly hostnames, not for
// autoconfig or mta-sts DNS records, they can be requested on demand (perhaps
// never).
ensureHosts := map[dns.Domain]struct{}{}
if l.TLS != nil && l.TLS.ACME != "" {
m := mox.Conf.Static.ACME[l.TLS.ACME].Manager
m.AllowHostname(mox.Conf.Static.HostnameDomain)
ensureHosts[mox.Conf.Static.HostnameDomain] = struct{}{}
if l.HostnameDomain.ASCII != "" {
m.AllowHostname(l.HostnameDomain)
ensureHosts[l.HostnameDomain] = struct{}{}
}
go func() {
// Just in case someone adds quite some domains to their config. We don't want to
// hit any ACME rate limits.
if len(ensureHosts) > 10 {
return
}
time.Sleep(1 * time.Second)
i := 0
for hostname := range ensureHosts {
if i > 0 {
// Sleep just a little. We don't want to hammer our ACME provider, e.g. Let's Encrypt.
time.Sleep(10 * time.Second)
}
i++
hello := &tls.ClientHelloInfo{
ServerName: hostname.ASCII,
// Make us fetch an ECDSA P256 cert.
// We add TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 to get around the ecDSA check in autocert.
CipherSuites: []uint16{tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, tls.TLS_AES_128_GCM_SHA256},
SupportedCurves: []tls.CurveID{tls.CurveP256},
SignatureSchemes: []tls.SignatureScheme{tls.ECDSAWithP256AndSHA256},
SupportedVersions: []uint16{tls.VersionTLS13},
}
xlog.Print("ensuring certificate availability", mlog.Field("hostname", hostname))
if _, err := m.Manager.GetCertificate(hello); err != nil {
xlog.Errorx("requesting automatic certificate", err, mlog.Field("hostname", hostname))
}
}
}()
}
for port, srv := range portServe {
for _, ip := range l.IPs {
listenAndServe(ip, port, srv.tlsConfig, name, srv.kinds, srv.mux)
}
}
}
}
// Only used when the account page is not active on the same listener.
func adminIndex(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
if r.Method != "GET" {
http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
return
}
http.Redirect(w, r, "/admin/", http.StatusSeeOther)
}
func listenAndServe(ip string, port int, tlsConfig *tls.Config, name string, kinds []string, mux *http.ServeMux) {
addr := net.JoinHostPort(ip, fmt.Sprintf("%d", port))
var protocol string
var ln net.Listener
var err error
if tlsConfig == nil {
protocol = "http"
xlog.Print("http listener", mlog.Field("name", name), mlog.Field("kinds", strings.Join(kinds, ",")), mlog.Field("address", addr))
ln, err = net.Listen(mox.Network(ip), addr)
if err != nil {
xlog.Fatalx("http: listen"+mox.LinuxSetcapHint(err), err, mlog.Field("addr", addr))
}
} else {
protocol = "https"
xlog.Print("https listener", mlog.Field("name", name), mlog.Field("kinds", strings.Join(kinds, ",")), mlog.Field("address", addr))
ln, err = tls.Listen(mox.Network(ip), addr, tlsConfig)
if err != nil {
xlog.Fatalx("https: listen"+mox.LinuxSetcapHint(err), err, mlog.Field("addr", addr))
}
}
server := &http.Server{
Handler: mux,
TLSConfig: tlsConfig,
ErrorLog: golog.New(mlog.ErrWriter(xlog.Fields(mlog.Field("pkg", "net/http")), mlog.LevelInfo, protocol+" error"), "", 0),
}
go func() {
err := server.Serve(ln)
xlog.Fatalx(protocol+": serve", err)
}()
}