254 lines
6.6 KiB
Go
254 lines
6.6 KiB
Go
package dbus
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"errors"
|
|
"io"
|
|
"os"
|
|
"strconv"
|
|
)
|
|
|
|
// AuthStatus represents the Status of an authentication mechanism.
|
|
type AuthStatus byte
|
|
|
|
const (
|
|
// AuthOk signals that authentication is finished; the next command
|
|
// from the server should be an OK.
|
|
AuthOk AuthStatus = iota
|
|
|
|
// AuthContinue signals that additional data is needed; the next command
|
|
// from the server should be a DATA.
|
|
AuthContinue
|
|
|
|
// AuthError signals an error; the server sent invalid data or some
|
|
// other unexpected thing happened and the current authentication
|
|
// process should be aborted.
|
|
AuthError
|
|
)
|
|
|
|
type authState byte
|
|
|
|
const (
|
|
waitingForData authState = iota
|
|
waitingForOk
|
|
waitingForReject
|
|
)
|
|
|
|
// Auth defines the behaviour of an authentication mechanism.
|
|
type Auth interface {
|
|
// Return the name of the mechnism, the argument to the first AUTH command
|
|
// and the next status.
|
|
FirstData() (name, resp []byte, status AuthStatus)
|
|
|
|
// Process the given DATA command, and return the argument to the DATA
|
|
// command and the next status. If len(resp) == 0, no DATA command is sent.
|
|
HandleData(data []byte) (resp []byte, status AuthStatus)
|
|
}
|
|
|
|
// Auth authenticates the connection, trying the given list of authentication
|
|
// mechanisms (in that order). If nil is passed, the EXTERNAL and
|
|
// DBUS_COOKIE_SHA1 mechanisms are tried for the current user. For private
|
|
// connections, this method must be called before sending any messages to the
|
|
// bus. Auth must not be called on shared connections.
|
|
func (conn *Conn) Auth(methods []Auth) error {
|
|
if methods == nil {
|
|
uid := strconv.Itoa(os.Getuid())
|
|
methods = []Auth{AuthExternal(uid), AuthCookieSha1(uid, getHomeDir())}
|
|
}
|
|
in := bufio.NewReader(conn.transport)
|
|
err := conn.transport.SendNullByte()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = authWriteLine(conn.transport, []byte("AUTH"))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
s, err := authReadLine(in)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if len(s) < 2 || !bytes.Equal(s[0], []byte("REJECTED")) {
|
|
return errors.New("dbus: authentication protocol error")
|
|
}
|
|
s = s[1:]
|
|
for _, v := range s {
|
|
for _, m := range methods {
|
|
if name, data, status := m.FirstData(); bytes.Equal(v, name) {
|
|
var ok bool
|
|
err = authWriteLine(conn.transport, []byte("AUTH"), []byte(v), data)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
switch status {
|
|
case AuthOk:
|
|
err, ok = conn.tryAuth(m, waitingForOk, in)
|
|
case AuthContinue:
|
|
err, ok = conn.tryAuth(m, waitingForData, in)
|
|
default:
|
|
panic("dbus: invalid authentication status")
|
|
}
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if ok {
|
|
if conn.transport.SupportsUnixFDs() {
|
|
err = authWriteLine(conn, []byte("NEGOTIATE_UNIX_FD"))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
line, err := authReadLine(in)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
switch {
|
|
case bytes.Equal(line[0], []byte("AGREE_UNIX_FD")):
|
|
conn.EnableUnixFDs()
|
|
conn.unixFD = true
|
|
case bytes.Equal(line[0], []byte("ERROR")):
|
|
default:
|
|
return errors.New("dbus: authentication protocol error")
|
|
}
|
|
}
|
|
err = authWriteLine(conn.transport, []byte("BEGIN"))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
go conn.inWorker()
|
|
go conn.outWorker()
|
|
return nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return errors.New("dbus: authentication failed")
|
|
}
|
|
|
|
// tryAuth tries to authenticate with m as the mechanism, using state as the
|
|
// initial authState and in for reading input. It returns (nil, true) on
|
|
// success, (nil, false) on a REJECTED and (someErr, false) if some other
|
|
// error occured.
|
|
func (conn *Conn) tryAuth(m Auth, state authState, in *bufio.Reader) (error, bool) {
|
|
for {
|
|
s, err := authReadLine(in)
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
switch {
|
|
case state == waitingForData && string(s[0]) == "DATA":
|
|
if len(s) != 2 {
|
|
err = authWriteLine(conn.transport, []byte("ERROR"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
continue
|
|
}
|
|
data, status := m.HandleData(s[1])
|
|
switch status {
|
|
case AuthOk, AuthContinue:
|
|
if len(data) != 0 {
|
|
err = authWriteLine(conn.transport, []byte("DATA"), data)
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
}
|
|
if status == AuthOk {
|
|
state = waitingForOk
|
|
}
|
|
case AuthError:
|
|
err = authWriteLine(conn.transport, []byte("ERROR"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
}
|
|
case state == waitingForData && string(s[0]) == "REJECTED":
|
|
return nil, false
|
|
case state == waitingForData && string(s[0]) == "ERROR":
|
|
err = authWriteLine(conn.transport, []byte("CANCEL"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
state = waitingForReject
|
|
case state == waitingForData && string(s[0]) == "OK":
|
|
if len(s) != 2 {
|
|
err = authWriteLine(conn.transport, []byte("CANCEL"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
state = waitingForReject
|
|
}
|
|
conn.uuid = string(s[1])
|
|
return nil, true
|
|
case state == waitingForData:
|
|
err = authWriteLine(conn.transport, []byte("ERROR"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
case state == waitingForOk && string(s[0]) == "OK":
|
|
if len(s) != 2 {
|
|
err = authWriteLine(conn.transport, []byte("CANCEL"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
state = waitingForReject
|
|
}
|
|
conn.uuid = string(s[1])
|
|
return nil, true
|
|
case state == waitingForOk && string(s[0]) == "REJECTED":
|
|
return nil, false
|
|
case state == waitingForOk && (string(s[0]) == "DATA" ||
|
|
string(s[0]) == "ERROR"):
|
|
|
|
err = authWriteLine(conn.transport, []byte("CANCEL"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
state = waitingForReject
|
|
case state == waitingForOk:
|
|
err = authWriteLine(conn.transport, []byte("ERROR"))
|
|
if err != nil {
|
|
return err, false
|
|
}
|
|
case state == waitingForReject && string(s[0]) == "REJECTED":
|
|
return nil, false
|
|
case state == waitingForReject:
|
|
return errors.New("dbus: authentication protocol error"), false
|
|
default:
|
|
panic("dbus: invalid auth state")
|
|
}
|
|
}
|
|
}
|
|
|
|
// authReadLine reads a line and separates it into its fields.
|
|
func authReadLine(in *bufio.Reader) ([][]byte, error) {
|
|
data, err := in.ReadBytes('\n')
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
data = bytes.TrimSuffix(data, []byte("\r\n"))
|
|
return bytes.Split(data, []byte{' '}), nil
|
|
}
|
|
|
|
// authWriteLine writes the given line in the authentication protocol format
|
|
// (elements of data separated by a " " and terminated by "\r\n").
|
|
func authWriteLine(out io.Writer, data ...[]byte) error {
|
|
buf := make([]byte, 0)
|
|
for i, v := range data {
|
|
buf = append(buf, v...)
|
|
if i != len(data)-1 {
|
|
buf = append(buf, ' ')
|
|
}
|
|
}
|
|
buf = append(buf, '\r')
|
|
buf = append(buf, '\n')
|
|
n, err := out.Write(buf)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if n != len(buf) {
|
|
return io.ErrUnexpectedEOF
|
|
}
|
|
return nil
|
|
}
|