forked from fangdingjun/obfssh
/
server.go
159 lines (138 loc) · 3.6 KB
/
server.go
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package main
import (
"bytes"
"crypto/tls"
"errors"
"flag"
"fmt"
"io/ioutil"
"net"
"os"
"github.com/fangdingjun/go-log"
"github.com/fangdingjun/obfssh"
"golang.org/x/crypto/ssh"
)
func main() {
var configfile string
var logfile string
var logFileCount int
var logFileSize int64
var loglevel string
flag.StringVar(&configfile, "c", "config.yaml", "configure file")
flag.StringVar(&logfile, "log_file", "", "log file, default stdout")
flag.IntVar(&logFileCount, "log_count", 10, "max count of log to keep")
flag.Int64Var(&logFileSize, "log_size", 10, "max log file size MB")
flag.StringVar(&loglevel, "log_level", "INFO", "log level, values:\nOFF, FATAL, PANIC, ERROR, WARN, INFO, DEBUG")
flag.Parse()
if logfile != "" {
log.Default.Out = &log.FixedSizeFileWriter{
MaxCount: logFileCount,
Name: logfile,
MaxSize: logFileSize * 1024 * 1024,
}
}
if loglevel != "" {
lv, err := log.ParseLevel(loglevel)
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
log.Default.Level = lv
}
conf, err := loadConfig(configfile)
if err != nil {
log.Fatal(err)
}
sconf := &obfssh.Conf{}
config := &ssh.ServerConfig{
PasswordCallback: func(c ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
if u, err := conf.getUser(c.User()); err == nil {
if u.Password != "" && c.User() == u.Username && string(pass) == u.Password {
return nil, nil
}
}
return nil, fmt.Errorf("password reject for user %s", c.User())
},
PublicKeyCallback: func(c ssh.ConnMetadata, k ssh.PublicKey) (*ssh.Permissions, error) {
checker := &ssh.CertChecker{
IsUserAuthority: func(k ssh.PublicKey) bool {
if u, err := conf.getUser(c.User()); err == nil {
for _, pk := range u.publicKeys {
if k.Type() == pk.Type() &&
bytes.Compare(k.Marshal(), pk.Marshal()) == 0 {
return true
}
}
}
return false
},
}
checker.UserKeyFallback = func(c1 ssh.ConnMetadata, k1 ssh.PublicKey) (*ssh.Permissions, error) {
log.Debug("user key fallback")
if checker.IsUserAuthority(k1) {
return nil, nil
}
return nil, errors.New("public not acceptable")
}
return checker.Authenticate(c, k)
},
// auth log
AuthLogCallback: func(c ssh.ConnMetadata, method string, err error) {
if err != nil {
log.Debugf("%s", err.Error())
log.Debugf("%s auth failed for %s from %s", method, c.User(), c.RemoteAddr())
} else {
log.Debugf("Accepted %s for user %s from %s", method, c.User(), c.RemoteAddr())
}
},
}
privateBytes, err := ioutil.ReadFile(conf.HostKey)
if err != nil {
log.Fatal(err)
}
private, err := ssh.ParsePrivateKey(privateBytes)
if err != nil {
log.Fatal(err)
}
config.AddHostKey(private)
for _, lst := range conf.Listen {
go func(lst listen) {
var l net.Listener
var err error
if lst.Key == "" || lst.Cert == "" {
l, err = net.Listen("tcp", fmt.Sprintf(":%d", lst.Port))
} else {
cert, err := tls.LoadX509KeyPair(lst.Cert, lst.Key)
if err != nil {
log.Fatal(err)
}
l, err = tls.Listen("tcp", fmt.Sprintf(":%d", lst.Port), &tls.Config{
Certificates: []tls.Certificate{cert},
})
}
if err != nil {
log.Fatal(err)
}
defer l.Close()
for {
c, err := l.Accept()
if err != nil {
fmt.Println(err)
return
}
log.Debugf("accept tcp connection from %s", c.RemoteAddr())
go func(c net.Conn) {
defer c.Close()
sc, err := obfssh.NewServer(c, config, sconf)
if err != nil {
c.Close()
log.Errorf("%s", err.Error())
return
}
sc.Run()
}(c)
}
}(lst)
}
select {}
}