AdGuardHome/home/control_tls.go
2019-07-19 12:18:16 +03:00

339 lines
9.4 KiB
Go

// Control: TLS configuring handlers
package home
import (
"context"
"crypto"
"crypto/ecdsa"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"encoding/base64"
"encoding/json"
"encoding/pem"
"errors"
"fmt"
"net/http"
"reflect"
"strings"
"time"
"github.com/AdguardTeam/golibs/log"
"github.com/joomcode/errorx"
)
// RegisterTLSHandlers registers HTTP handlers for TLS configuration
func RegisterTLSHandlers() {
http.HandleFunc("/control/tls/status", postInstall(optionalAuth(ensureGET(handleTLSStatus))))
http.HandleFunc("/control/tls/configure", postInstall(optionalAuth(ensurePOST(handleTLSConfigure))))
http.HandleFunc("/control/tls/validate", postInstall(optionalAuth(ensurePOST(handleTLSValidate))))
}
func handleTLSStatus(w http.ResponseWriter, r *http.Request) {
log.Tracef("%s %v", r.Method, r.URL)
marshalTLS(w, config.TLS)
}
func handleTLSValidate(w http.ResponseWriter, r *http.Request) {
log.Tracef("%s %v", r.Method, r.URL)
data, err := unmarshalTLS(r)
if err != nil {
httpError(w, http.StatusBadRequest, "Failed to unmarshal TLS config: %s", err)
return
}
// check if port is available
// BUT: if we are already using this port, no need
alreadyRunning := false
if config.httpsServer.server != nil {
alreadyRunning = true
}
if !alreadyRunning {
err = checkPortAvailable(config.BindHost, data.PortHTTPS)
if err != nil {
httpError(w, http.StatusBadRequest, "port %d is not available, cannot enable HTTPS on it", data.PortHTTPS)
return
}
}
data.tlsConfigStatus = validateCertificates(data.CertificateChain, data.PrivateKey, data.ServerName)
marshalTLS(w, data)
}
func handleTLSConfigure(w http.ResponseWriter, r *http.Request) {
log.Tracef("%s %v", r.Method, r.URL)
data, err := unmarshalTLS(r)
if err != nil {
httpError(w, http.StatusBadRequest, "Failed to unmarshal TLS config: %s", err)
return
}
// check if port is available
// BUT: if we are already using this port, no need
alreadyRunning := false
if config.httpsServer.server != nil {
alreadyRunning = true
}
if !alreadyRunning {
err = checkPortAvailable(config.BindHost, data.PortHTTPS)
if err != nil {
httpError(w, http.StatusBadRequest, "port %d is not available, cannot enable HTTPS on it", data.PortHTTPS)
return
}
}
restartHTTPS := false
data.tlsConfigStatus = validateCertificates(data.CertificateChain, data.PrivateKey, data.ServerName)
if !reflect.DeepEqual(config.TLS.tlsConfigSettings, data.tlsConfigSettings) {
log.Printf("tls config settings have changed, will restart HTTPS server")
restartHTTPS = true
}
config.TLS = data
err = writeAllConfigsAndReloadDNS()
if err != nil {
httpError(w, http.StatusInternalServerError, "Couldn't write config file: %s", err)
return
}
marshalTLS(w, data)
// this needs to be done in a goroutine because Shutdown() is a blocking call, and it will block
// until all requests are finished, and _we_ are inside a request right now, so it will block indefinitely
if restartHTTPS {
go func() {
time.Sleep(time.Second) // TODO: could not find a way to reliably know that data was fully sent to client by https server, so we wait a bit to let response through before closing the server
config.httpsServer.cond.L.Lock()
config.httpsServer.cond.Broadcast()
if config.httpsServer.server != nil {
config.httpsServer.server.Shutdown(context.TODO())
}
config.httpsServer.cond.L.Unlock()
}()
}
}
func verifyCertChain(data *tlsConfigStatus, certChain string, serverName string) error {
log.Tracef("got certificate: %s", certChain)
// now do a more extended validation
var certs []*pem.Block // PEM-encoded certificates
var skippedBytes []string // skipped bytes
pemblock := []byte(certChain)
for {
var decoded *pem.Block
decoded, pemblock = pem.Decode(pemblock)
if decoded == nil {
break
}
if decoded.Type == "CERTIFICATE" {
certs = append(certs, decoded)
} else {
skippedBytes = append(skippedBytes, decoded.Type)
}
}
var parsedCerts []*x509.Certificate
for _, cert := range certs {
parsed, err := x509.ParseCertificate(cert.Bytes)
if err != nil {
data.WarningValidation = fmt.Sprintf("Failed to parse certificate: %s", err)
return errors.New(data.WarningValidation)
}
parsedCerts = append(parsedCerts, parsed)
}
if len(parsedCerts) == 0 {
data.WarningValidation = fmt.Sprintf("You have specified an empty certificate")
return errors.New(data.WarningValidation)
}
data.ValidCert = true
// spew.Dump(parsedCerts)
opts := x509.VerifyOptions{
DNSName: serverName,
}
log.Printf("number of certs - %d", len(parsedCerts))
if len(parsedCerts) > 1 {
// set up an intermediate
pool := x509.NewCertPool()
for _, cert := range parsedCerts[1:] {
log.Printf("got an intermediate cert")
pool.AddCert(cert)
}
opts.Intermediates = pool
}
// TODO: save it as a warning rather than error it out -- shouldn't be a big problem
mainCert := parsedCerts[0]
_, err := mainCert.Verify(opts)
if err != nil {
// let self-signed certs through
data.WarningValidation = fmt.Sprintf("Your certificate does not verify: %s", err)
} else {
data.ValidChain = true
}
// spew.Dump(chains)
// update status
if mainCert != nil {
notAfter := mainCert.NotAfter
data.Subject = mainCert.Subject.String()
data.Issuer = mainCert.Issuer.String()
data.NotAfter = notAfter
data.NotBefore = mainCert.NotBefore
data.DNSNames = mainCert.DNSNames
}
return nil
}
func validatePkey(data *tlsConfigStatus, pkey string) error {
// now do a more extended validation
var key *pem.Block // PEM-encoded certificates
var skippedBytes []string // skipped bytes
// go through all pem blocks, but take first valid pem block and drop the rest
pemblock := []byte(pkey)
for {
var decoded *pem.Block
decoded, pemblock = pem.Decode(pemblock)
if decoded == nil {
break
}
if decoded.Type == "PRIVATE KEY" || strings.HasSuffix(decoded.Type, " PRIVATE KEY") {
key = decoded
break
} else {
skippedBytes = append(skippedBytes, decoded.Type)
}
}
if key == nil {
data.WarningValidation = "No valid keys were found"
return errors.New(data.WarningValidation)
}
// parse the decoded key
_, keytype, err := parsePrivateKey(key.Bytes)
if err != nil {
data.WarningValidation = fmt.Sprintf("Failed to parse private key: %s", err)
return errors.New(data.WarningValidation)
}
data.ValidKey = true
data.KeyType = keytype
return nil
}
// Process certificate data and its private key.
// All parameters are optional.
// On error, return partially set object
// with 'WarningValidation' field containing error description.
func validateCertificates(certChain, pkey, serverName string) tlsConfigStatus {
var data tlsConfigStatus
// check only public certificate separately from the key
if certChain != "" {
if verifyCertChain(&data, certChain, serverName) != nil {
return data
}
}
// validate private key (right now the only validation possible is just parsing it)
if pkey != "" {
if validatePkey(&data, pkey) != nil {
return data
}
}
// if both are set, validate both in unison
if pkey != "" && certChain != "" {
_, err := tls.X509KeyPair([]byte(certChain), []byte(pkey))
if err != nil {
data.WarningValidation = fmt.Sprintf("Invalid certificate or key: %s", err)
return data
}
data.ValidPair = true
}
return data
}
// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
func parsePrivateKey(der []byte) (crypto.PrivateKey, string, error) {
if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
return key, "RSA", nil
}
if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
switch key := key.(type) {
case *rsa.PrivateKey:
return key, "RSA", nil
case *ecdsa.PrivateKey:
return key, "ECDSA", nil
default:
return nil, "", errors.New("tls: found unknown private key type in PKCS#8 wrapping")
}
}
if key, err := x509.ParseECPrivateKey(der); err == nil {
return key, "ECDSA", nil
}
return nil, "", errors.New("tls: failed to parse private key")
}
// unmarshalTLS handles base64-encoded certificates transparently
func unmarshalTLS(r *http.Request) (tlsConfig, error) {
data := tlsConfig{}
err := json.NewDecoder(r.Body).Decode(&data)
if err != nil {
return data, errorx.Decorate(err, "Failed to parse new TLS config json")
}
if data.CertificateChain != "" {
certPEM, err := base64.StdEncoding.DecodeString(data.CertificateChain)
if err != nil {
return data, errorx.Decorate(err, "Failed to base64-decode certificate chain")
}
data.CertificateChain = string(certPEM)
}
if data.PrivateKey != "" {
keyPEM, err := base64.StdEncoding.DecodeString(data.PrivateKey)
if err != nil {
return data, errorx.Decorate(err, "Failed to base64-decode private key")
}
data.PrivateKey = string(keyPEM)
}
return data, nil
}
func marshalTLS(w http.ResponseWriter, data tlsConfig) {
w.Header().Set("Content-Type", "application/json")
if data.CertificateChain != "" {
encoded := base64.StdEncoding.EncodeToString([]byte(data.CertificateChain))
data.CertificateChain = encoded
}
if data.PrivateKey != "" {
encoded := base64.StdEncoding.EncodeToString([]byte(data.PrivateKey))
data.PrivateKey = encoded
}
err := json.NewEncoder(w).Encode(data)
if err != nil {
httpError(w, http.StatusInternalServerError, "Failed to marshal json with TLS status: %s", err)
return
}
}