rdpgw/cmd/auth/auth.go
2022-09-09 16:44:19 +02:00

98 lines
2.3 KiB
Go

package main
import (
"context"
"errors"
"github.com/bolkedebruin/rdpgw/shared/auth"
"github.com/msteinert/pam"
"github.com/thought-machine/go-flags"
"google.golang.org/grpc"
"log"
"net"
"os"
"syscall"
)
const (
protocol = "unix"
)
var opts struct {
ServiceName string `short:"n" long:"name" default:"rdpgw" description:"the PAM service name to use"`
SocketAddr string `short:"s" long:"socket" default:"/tmp/rdpgw-auth.sock" description:"the location of the socket"`
}
type AuthServiceImpl struct {
serviceName string
}
var _ auth.AuthenticateServer = (*AuthServiceImpl)(nil)
func NewAuthService(serviceName string) auth.AuthenticateServer {
s := &AuthServiceImpl{serviceName: serviceName}
return s
}
func (s *AuthServiceImpl) Authenticate(ctx context.Context, message *auth.UserPass) (*auth.AuthResponse, error) {
t, err := pam.StartFunc(s.serviceName, message.Username, func(s pam.Style, msg string) (string, error) {
switch s {
case pam.PromptEchoOff:
return message.Password, nil
case pam.PromptEchoOn, pam.ErrorMsg, pam.TextInfo:
return "", nil
}
return "", errors.New("unrecognized PAM message style")
})
r := &auth.AuthResponse{}
r.Authenticated = false
if err != nil {
log.Printf("Error authenticating user: %s due to: %s", message.Username, err)
r.Error = err.Error()
return r, err
}
if err = t.Authenticate(0); err != nil {
log.Printf("Authentication for user: %s failed due to: %s", message.Username, err)
r.Error = err.Error()
return r, nil
}
if err = t.AcctMgmt(0); err != nil {
log.Printf("Account authorization for user: %s failed due to %s", message.Username, err)
r.Error = err.Error()
return r, nil
}
log.Printf("User: %s authenticated", message.Username)
r.Authenticated = true
return r, nil
}
func main() {
_, err := flags.Parse(&opts)
if err != nil {
panic(err)
}
log.Printf("Starting auth server on %s", opts.SocketAddr)
cleanup := func() {
if _, err := os.Stat(opts.SocketAddr); err == nil {
if err := os.RemoveAll(opts.SocketAddr); err != nil {
log.Fatal(err)
}
}
}
cleanup()
oldUmask := syscall.Umask(0)
listener, err := net.Listen(protocol, opts.SocketAddr)
syscall.Umask(oldUmask)
if err != nil {
log.Fatal(err)
}
server := grpc.NewServer()
service := NewAuthService(opts.ServiceName)
auth.RegisterAuthenticateServer(server, service)
server.Serve(listener)
}