open-nomad/vendor/github.com/godbus/dbus/auth_sha1.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

103 lines
2.4 KiB
Go

package dbus
import (
"bufio"
"bytes"
"crypto/rand"
"crypto/sha1"
"encoding/hex"
"os"
)
// AuthCookieSha1 returns an Auth that authenticates as the given user with the
// DBUS_COOKIE_SHA1 mechanism. The home parameter should specify the home
// directory of the user.
func AuthCookieSha1(user, home string) Auth {
return authCookieSha1{user, home}
}
type authCookieSha1 struct {
user, home string
}
func (a authCookieSha1) FirstData() ([]byte, []byte, AuthStatus) {
b := make([]byte, 2*len(a.user))
hex.Encode(b, []byte(a.user))
return []byte("DBUS_COOKIE_SHA1"), b, AuthContinue
}
func (a authCookieSha1) HandleData(data []byte) ([]byte, AuthStatus) {
challenge := make([]byte, len(data)/2)
_, err := hex.Decode(challenge, data)
if err != nil {
return nil, AuthError
}
b := bytes.Split(challenge, []byte{' '})
if len(b) != 3 {
return nil, AuthError
}
context := b[0]
id := b[1]
svchallenge := b[2]
cookie := a.getCookie(context, id)
if cookie == nil {
return nil, AuthError
}
clchallenge := a.generateChallenge()
if clchallenge == nil {
return nil, AuthError
}
hash := sha1.New()
hash.Write(bytes.Join([][]byte{svchallenge, clchallenge, cookie}, []byte{':'}))
hexhash := make([]byte, 2*hash.Size())
hex.Encode(hexhash, hash.Sum(nil))
data = append(clchallenge, ' ')
data = append(data, hexhash...)
resp := make([]byte, 2*len(data))
hex.Encode(resp, data)
return resp, AuthOk
}
// getCookie searches for the cookie identified by id in context and returns
// the cookie content or nil. (Since HandleData can't return a specific error,
// but only whether an error occured, this function also doesn't bother to
// return an error.)
func (a authCookieSha1) getCookie(context, id []byte) []byte {
file, err := os.Open(a.home + "/.dbus-keyrings/" + string(context))
if err != nil {
return nil
}
defer file.Close()
rd := bufio.NewReader(file)
for {
line, err := rd.ReadBytes('\n')
if err != nil {
return nil
}
line = line[:len(line)-1]
b := bytes.Split(line, []byte{' '})
if len(b) != 3 {
return nil
}
if bytes.Equal(b[0], id) {
return b[2]
}
}
}
// generateChallenge returns a random, hex-encoded challenge, or nil on error
// (see above).
func (a authCookieSha1) generateChallenge() []byte {
b := make([]byte, 16)
n, err := rand.Read(b)
if err != nil {
return nil
}
if n != 16 {
return nil
}
enc := make([]byte, 32)
hex.Encode(enc, b)
return enc
}