dnscrypt-proxy/serversInfo.go

116 lines
3.0 KiB
Go

package main
import (
"encoding/hex"
"fmt"
"log"
"math/rand"
"net"
"strings"
"sync"
"time"
"golang.org/x/crypto/ed25519"
)
type ServerStamp struct {
serverAddrStr string
serverPkStr string
providerName string
}
type RegisteredServer struct {
name string
stamp ServerStamp
}
func NewServerStampFromLegacy(serverAddrStr string, serverPkStr string, providerName string) (ServerStamp, error) {
return ServerStamp{
serverAddrStr: serverAddrStr,
serverPkStr: serverPkStr,
providerName: providerName,
}, nil
}
type ServerInfo struct {
MagicQuery [8]byte
ServerPk [32]byte
SharedKey [32]byte
CryptoConstruction CryptoConstruction
Name string
Timeout time.Duration
UDPAddr *net.UDPAddr
TCPAddr *net.TCPAddr
}
type ServersInfo struct {
sync.RWMutex
inner []ServerInfo
registeredServers []RegisteredServer
}
func (serversInfo *ServersInfo) registerServer(proxy *Proxy, name string, stamp ServerStamp) error {
serversInfo.Lock()
defer serversInfo.Unlock()
newServer, err := serversInfo.fetchServerInfo(proxy, name, stamp)
if err != nil {
return err
}
for i, oldServer := range serversInfo.inner {
if oldServer.Name == newServer.Name {
serversInfo.inner[i] = newServer
return nil
}
}
serversInfo.inner = append(serversInfo.inner, newServer)
serversInfo.registeredServers = append(serversInfo.registeredServers, RegisteredServer{name: name, stamp: stamp})
return nil
}
func (serversInfo *ServersInfo) refresh(proxy *Proxy) {
fmt.Println("Refreshing certificates")
serversInfo.RLock()
registeredServers := serversInfo.registeredServers
serversInfo.RUnlock()
for _, registeredServer := range registeredServers {
serversInfo.registerServer(proxy, registeredServer.name, registeredServer.stamp)
}
}
func (serversInfo *ServersInfo) getOne() *ServerInfo {
serversInfo.RLock()
serverInfo := &serversInfo.inner[rand.Intn(len(serversInfo.inner))]
serversInfo.RUnlock()
return serverInfo
}
func (serversInfo *ServersInfo) fetchServerInfo(proxy *Proxy, name string, stamp ServerStamp) (ServerInfo, error) {
serverPk, err := hex.DecodeString(strings.Replace(stamp.serverPkStr, ":", "", -1))
if err != nil || len(serverPk) != ed25519.PublicKeySize {
log.Fatal("Invalid public key")
}
certInfo, err := FetchCurrentCert(proxy, serverPk, stamp.serverAddrStr, stamp.providerName)
if err != nil {
return ServerInfo{}, err
}
remoteUDPAddr, err := net.ResolveUDPAddr("udp", stamp.serverAddrStr)
if err != nil {
return ServerInfo{}, err
}
remoteTCPAddr, err := net.ResolveTCPAddr("tcp", stamp.serverAddrStr)
if err != nil {
return ServerInfo{}, err
}
serverInfo := ServerInfo{
MagicQuery: certInfo.MagicQuery,
ServerPk: certInfo.ServerPk,
SharedKey: certInfo.SharedKey,
CryptoConstruction: certInfo.CryptoConstruction,
Name: name,
Timeout: TimeoutMin,
UDPAddr: remoteUDPAddr,
TCPAddr: remoteTCPAddr,
}
return serverInfo, nil
}