Support using DOH server for type 65 query

infra/conf/transport_internet.go

@@ -390,6 +390,7 @@ type TLSConfig struct {
 	PinnedPeerCertificatePublicKeySha256 *[]string        `json:"pinnedPeerCertificatePublicKeySha256"`
 	MasterKeyLog                         string           `json:"masterKeyLog"`
 	ECHConfig                            string           `json:"echConfig"`
+	ECHDOHServer                         string           `json:"echDohServer"`
 }
 
 // Build implements Buildable.
@@ -446,6 +447,7 @@ func (c *TLSConfig) Build() (proto.Message, error) {
 
 	config.MasterKeyLog = c.MasterKeyLog
 	config.EchConfig = c.ECHConfig
+	config.Ech_DOHserver = c.ECHDOHServer
 
 	return config, nil
 }

transport/internet/tls/config.go

@@ -390,7 +390,7 @@ func (c *Config) GetTLSConfig(opts ...Option) *tls.Config {
 			config.KeyLogWriter = writer
 		}
 	}
-	if len(c.EchConfig) > 0 {
+	if len(c.EchConfig) > 0 || len(c.Ech_DOHserver) > 0 {
 		err := ApplyECH(c, config)
 		if err != nil {
 			errors.LogError(context.Background(), err)

transport/internet/tls/config.pb.go

@@ -221,6 +221,7 @@ type Config struct {
 	PinnedPeerCertificatePublicKeySha256 [][]byte `protobuf:"bytes,14,rep,name=pinned_peer_certificate_public_key_sha256,json=pinnedPeerCertificatePublicKeySha256,proto3" json:"pinned_peer_certificate_public_key_sha256,omitempty"`
 	MasterKeyLog                         string   `protobuf:"bytes,15,opt,name=master_key_log,json=masterKeyLog,proto3" json:"master_key_log,omitempty"`
 	EchConfig                            string   `protobuf:"bytes,16,opt,name=ech_config,json=echConfig,proto3" json:"ech_config,omitempty"`
+	Ech_DOHserver                        string   `protobuf:"bytes,17,opt,name=ech_DOHserver,json=echDOHserver,proto3" json:"ech_DOHserver,omitempty"`
 }
 
 func (x *Config) Reset() {
@@ -368,6 +369,13 @@ func (x *Config) GetEchConfig() string {
 	return ""
 }
 
+func (x *Config) GetEch_DOHserver() string {
+	if x != nil {
+		return x.Ech_DOHserver
+	}
+	return ""
+}
+
 var File_transport_internet_tls_config_proto protoreflect.FileDescriptor
 
 var file_transport_internet_tls_config_proto_rawDesc = []byte{
@@ -399,7 +407,7 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x4e, 0x43, 0x49, 0x50, 0x48, 0x45, 0x52, 0x4d, 0x45, 0x4e, 0x54, 0x10, 0x00, 0x12, 0x14, 0x0a,
 	0x10, 0x41, 0x55, 0x54, 0x48, 0x4f, 0x52, 0x49, 0x54, 0x59, 0x5f, 0x56, 0x45, 0x52, 0x49, 0x46,
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+	0x5f, 0x49, 0x53, 0x53, 0x55, 0x45, 0x10, 0x02, 0x22, 0xba, 0x06, 0x0a, 0x06, 0x43, 0x6f, 0x6e,
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@@ -449,14 +457,17 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x01, 0x28, 0x09, 0x52, 0x0c, 0x6d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x4b, 0x65, 0x79, 0x4c, 0x6f,
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+	0x12, 0x23, 0x0a, 0x0d, 0x65, 0x63, 0x68, 0x5f, 0x44, 0x4f, 0x48, 0x73, 0x65, 0x72, 0x76, 0x65,
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+	0x72, 0x18, 0x11, 0x20, 0x01, 0x28, 0x09, 0x52, 0x0c, 0x65, 0x63, 0x68, 0x44, 0x4f, 0x48, 0x73,
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+	0x65, 0x72, 0x76, 0x65, 0x72, 0x42, 0x73, 0x0a, 0x1f, 0x63, 0x6f, 0x6d, 0x2e, 0x78, 0x72, 0x61,
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-	0x74, 0x2e, 0x54, 0x6c, 0x73, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x69, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2f, 0x74, 0x6c, 0x73, 0xaa, 0x02, 0x1b, 0x58,
+	0x72, 0x61, 0x79, 0x2e, 0x54, 0x72, 0x61, 0x6e, 0x73, 0x70, 0x6f, 0x72, 0x74, 0x2e, 0x49, 0x6e,
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+	0x6f, 0x33,
 }
 
 var (

transport/internet/tls/config.proto

@@ -89,4 +89,5 @@ message Config {
 
   string master_key_log = 15;
   string ech_config = 16;
+  string ech_DOHserver = 17;
 }

transport/internet/tls/ech.go

@@ -4,18 +4,107 @@
 package tls
 
 import (
-	"context"
+	"bytes"
 	"crypto/tls"
 	"encoding/base64"
+	"io"
+	"net/http"
+	"regexp"
+	"sync"
+	"time"
 
+	"github.com/miekg/dns"
 	"github.com/xtls/xray-core/common/errors"
 )
 
 func ApplyECH(c *Config, config *tls.Config) error {
-	ECHConfig, err := base64.StdEncoding.DecodeString(c.EchConfig)
+	var ECHConfig []byte
+	var err error
+
+	if len(c.EchConfig) > 0 {
+		ECHConfig, err = base64.StdEncoding.DecodeString(c.EchConfig)
 		if err != nil {
-		errors.LogError(context.Background(), "invalid ECH config")
+			return errors.New("invalid ECH config")
 		}
+	} else {
+		if c.ServerName == "" {
+			return errors.New("Using DOH for ECH needs serverName")
+		}
+		ECHRecord, err := QueryRecord(c.ServerName, c.Ech_DOHserver)
+		if err != nil {
+			return err
+		}
+		ECHConfig, _ = base64.StdEncoding.DecodeString(ECHRecord)
+	}
+
 	config.EncryptedClientHelloConfigList = ECHConfig
 	return nil
 }
+
+type record struct {
+	record string
+	expire time.Time
+}
+
+var (
+	dnsCache = make(map[string]record)
+	mutex    sync.RWMutex
+)
+
+func QueryRecord(domain string, server string) (string, error) {
+	mutex.RLock()
+	defer mutex.RUnlock()
+	rec, found := dnsCache[domain]
+	if found && rec.expire.After(time.Now()) {
+		return "", nil
+	}
+	record, err := dohQuery(server, domain)
+	if err != nil {
+		return "", err
+	}
+	rec.record = record
+	rec.expire = time.Now().Add(time.Second * 600)
+	return record, nil
+}
+
+func dohQuery(server string, domain string) (string, error) {
+	m := new(dns.Msg)
+	m.SetQuestion(dns.Fqdn(domain), dns.TypeHTTPS)
+	msg, err := m.Pack()
+	if err != nil {
+		return "", err
+	}
+	client := &http.Client{
+		Timeout: 5 * time.Second,
+	}
+	req, err := http.NewRequest("POST", server, bytes.NewReader(msg))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/dns-message")
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return "", errors.New("query failed with response code:", resp.StatusCode)
+	}
+	respMsg := new(dns.Msg)
+	err = respMsg.Unpack(respBody)
+	if err != nil {
+		return "", err
+	}
+	if len(respMsg.Answer) > 0 {
+		re := regexp.MustCompile(`ech="([^"]+)"`)
+		match := re.FindStringSubmatch(respMsg.Answer[0].String())
+		if match[1] != "" {
+			return match[1], nil
+		}
+	}
+	return "", errors.New("no ech record found")
+}