miracle091/dnscrypt-proxy
miracle091/dnscrypt-proxy
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Code Issues Releases Wiki Activity

Move a few things around

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This commit is contained in:
Frank Denis 2018-01-09 13:35:10 +01:00
parent 60a58067c1
commit 6a39b0afdb
2 changed files with 84 additions and 79 deletions
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11
common.go
View File

@ -1,6 +1,7 @@
package main
import (
"net"
"time"
)
@ -22,6 +23,16 @@ var (
TimeoutMax = 5 * time.Second
)
type ServerInfo struct {
MagicQuery [8]byte
ServerPk [32]byte
SharedKey [32]byte
CryptoConstruction CryptoConstruction
Timeout time.Duration
UDPAddr *net.UDPAddr
TCPAddr *net.TCPAddr
}
func HasTCFlag(packet []byte) bool {
return packet[2]&2 == 2
}

152
dnscrypt-proxy.go
View File

@ -20,6 +20,79 @@ type Proxy struct {
serversInfo []ServerInfo
}
func main() {
log.SetFlags(0)
_ = NewProxy("127.0.0.1:5399", "212.47.228.136:443", "E801:B84E:A606:BFB0:BAC0:CE43:445B:B15E:BA64:B02F:A3C4:AA31:AE10:636A:0790:324D", "2.dnscrypt-cert.fr.dnscrypt.org")
}
func NewProxy(listenAddrStr string, serverAddrStr string, serverPkStr string, providerName string) Proxy {
proxy := Proxy{minQuestionSize: InitialMinQuestionSize}
if _, err := rand.Read(proxy.proxySecretKey[:]); err != nil {
log.Fatal(err)
}
curve25519.ScalarBaseMult(&proxy.proxyPublicKey, &proxy.proxySecretKey)
proxy.fetchServerInfo(serverAddrStr, serverPkStr, providerName)
proxy.udpListener(listenAddrStr)
return proxy
}
func (proxy *Proxy) adjustMinQuestionSize() {
if MaxDNSPacketSize-proxy.minQuestionSize < proxy.minQuestionSize {
proxy.minQuestionSize = MaxDNSPacketSize
} else {
proxy.minQuestionSize *= 2
}
}
func (proxy *Proxy) udpListener(listenAddrStr string) error {
clientPc, err := net.ListenPacket("udp", listenAddrStr)
if err != nil {
return err
}
defer clientPc.Close()
fmt.Printf("Now listening to %v [UDP]\n", listenAddrStr)
for {
buffer := make([]byte, MaxDNSPacketSize)
length, clientAddr, err := clientPc.ReadFrom(buffer)
if err != nil {
return err
}
packet := buffer[:length]
go func() {
proxy.processIncomingUDPQuery(&proxy.serversInfo[0], packet, clientAddr, clientPc)
}()
}
}
func (proxy *Proxy) processIncomingUDPQuery(serverInfo *ServerInfo, packet []byte, clientAddr net.Addr, clientPc net.PacketConn) {
if len(packet) < MinDNSPacketSize {
return
}
encrypted, clientNonce := proxy.Crypt(serverInfo, packet)
pc, err := net.DialUDP("udp", nil, serverInfo.UDPAddr)
if err != nil {
return
}
defer pc.Close()
pc.SetDeadline(time.Now().Add(serverInfo.Timeout))
pc.Write(encrypted)
encrypted = make([]byte, MaxDNSPacketSize)
length, err := pc.Read(encrypted)
if err != nil {
return
}
encrypted = encrypted[:length]
packet, err = proxy.Decrypt(serverInfo, encrypted, clientNonce)
if err != nil {
return
}
clientPc.WriteTo(packet, clientAddr)
if HasTCFlag(packet) {
proxy.adjustMinQuestionSize()
}
}
func (proxy *Proxy) fetchServerInfo(serverAddrStr string, serverPkStr string, providerName string) {
serverPublicKey, err := hex.DecodeString(strings.Replace(serverPkStr, ":", "", -1))
if err != nil || len(serverPublicKey) != ed25519.PublicKeySize {
@ -48,82 +121,3 @@ func (proxy *Proxy) fetchServerInfo(serverAddrStr string, serverPkStr string, pr
}
proxy.serversInfo = append(proxy.serversInfo, serverInfo)
}
func NewProxy(listenAddrStr string, serverAddrStr string, serverPkStr string, providerName string) Proxy {
proxy := Proxy{minQuestionSize: InitialMinQuestionSize}
if _, err := rand.Read(proxy.proxySecretKey[:]); err != nil {
log.Fatal(err)
}
curve25519.ScalarBaseMult(&proxy.proxyPublicKey, &proxy.proxySecretKey)
proxy.fetchServerInfo(serverAddrStr, serverPkStr, providerName)
clientPc, err := net.ListenPacket("udp", listenAddrStr)
if err != nil {
log.Fatal(err)
}
defer clientPc.Close()
fmt.Printf("Now listening to %v [UDP]\n", listenAddrStr)
for {
buffer := make([]byte, MaxDNSPacketSize)
length, clientAddr, err := clientPc.ReadFrom(buffer)
if err != nil {
break
}
packet := buffer[:length]
go func() {
proxy.processIncomingQuery(&proxy.serversInfo[0], packet, clientAddr, clientPc)
}()
}
return proxy
}
type ServerInfo struct {
MagicQuery [8]byte
ServerPk [32]byte
SharedKey [32]byte
CryptoConstruction CryptoConstruction
Timeout time.Duration
UDPAddr *net.UDPAddr
TCPAddr *net.TCPAddr
}
func (proxy *Proxy) adjustMinQuestionSize() {
if MaxDNSPacketSize-proxy.minQuestionSize < proxy.minQuestionSize {
proxy.minQuestionSize = MaxDNSPacketSize
} else {
proxy.minQuestionSize *= 2
}
}
func (proxy *Proxy) processIncomingQuery(serverInfo *ServerInfo, packet []byte, clientAddr net.Addr, clientPc net.PacketConn) {
if len(packet) < MinDNSPacketSize {
return
}
encrypted, clientNonce := proxy.Crypt(serverInfo, packet)
pc, err := net.DialUDP("udp", nil, serverInfo.UDPAddr)
if err != nil {
return
}
defer pc.Close()
pc.SetDeadline(time.Now().Add(serverInfo.Timeout))
pc.Write(encrypted)
encrypted = make([]byte, MaxDNSPacketSize)
length, err := pc.Read(encrypted)
if err != nil {
return
}
encrypted = encrypted[:length]
packet, err = proxy.Decrypt(serverInfo, encrypted, clientNonce)
if err != nil {
return
}
clientPc.WriteTo(packet, clientAddr)
if HasTCFlag(packet) {
proxy.adjustMinQuestionSize()
}
}
func main() {
log.SetFlags(0)
_ = NewProxy("127.0.0.1:5399", "212.47.228.136:443", "E801:B84E:A606:BFB0:BAC0:CE43:445B:B15E:BA64:B02F:A3C4:AA31:AE10:636A:0790:324D", "2.dnscrypt-cert.fr.dnscrypt.org")
}