-
Notifications
You must be signed in to change notification settings - Fork 0
/
sudoless.go
154 lines (138 loc) · 3.28 KB
/
sudoless.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
package sudoless
import (
"crypto/tls"
"fmt"
"io/ioutil"
"log"
"net"
"os"
"os/exec"
"os/user"
"path/filepath"
"sort"
"strconv"
"strings"
"syscall"
)
type Sudoless struct {
Files []*os.File
pointer uintptr
}
var s = &Sudoless{pointer: 3}
func Port(p int) (net.Listener, error) {
if havePrivileges() {
log.Printf("Open port %v", p)
port, err := net.Listen("tcp", fmt.Sprintf(":%v", p))
if err != nil {
return nil, err
}
file, err := port.(*net.TCPListener).File()
if err != nil {
return nil, err
}
s.Files = append(s.Files, file)
return nil, nil
} else {
log.Printf("Listening port %v", p)
port, err := net.FileListener(os.NewFile(s.pointer, "[socket]"))
s.pointer++
if err != nil {
log.Fatal("Failed to listen ", err)
os.Exit(1)
}
return port, nil
}
}
func Certs(path string) []tls.Certificate {
certs := []tls.Certificate{}
possibleFiles, err := filepath.Glob(path)
sort.Strings(possibleFiles)
var certFile, keyFile *os.File
if havePrivileges() {
for i := 0; i < len(possibleFiles)-1; i++ {
if (strings.HasSuffix(possibleFiles[i], "fullchain.pem") && strings.HasSuffix(possibleFiles[i+1], "privkey.pem")) ||
(strings.HasSuffix(possibleFiles[i], "server.crt") && strings.HasSuffix(possibleFiles[i+1], "server.key")) {
certFile, err = os.Open(possibleFiles[i])
if err != nil {
log.Fatal("error loading cert:", err)
}
keyFile, err = os.Open(possibleFiles[i+1])
if err != nil {
log.Fatal("error loading key:", err)
}
s.Files = append(s.Files, certFile, keyFile)
i++
}
}
} else {
fdCount, err := strconv.Atoi(os.Args[len(os.Args)-1])
os.Args = os.Args[:len(os.Args)-1]
if err != nil {
log.Fatal("Failed to parse fdCount", err)
}
for int(s.pointer) < fdCount {
certFile := os.NewFile(s.pointer, "[socket]")
defer certFile.Close()
keyFile := os.NewFile(s.pointer+1, "[socket]")
defer keyFile.Close()
s.pointer += 2
certBytes, err := ioutil.ReadAll(certFile)
if err != nil {
log.Fatal("Failed to read cert", err)
}
keyBytes, err := ioutil.ReadAll(keyFile)
if err != nil {
log.Fatal("Failed to read key", err)
}
cert, err := tls.X509KeyPair(certBytes, keyBytes)
if err != nil {
log.Fatal("error building cert: %v", err)
}
certs = append(certs, cert)
}
}
return certs
}
func DropPrivileges(u string) error {
if havePrivileges() {
log.Println("Starting as user", u)
cmd := exec.Command(os.Args[0], append(os.Args[1:], fmt.Sprintf("%v", len(s.Files)+3))...)
cmd.ExtraFiles = s.Files
unprivilegedUser, err := user.Lookup(u)
if err != nil {
return err
}
uid, err := strconv.Atoi(unprivilegedUser.Uid)
if err != nil {
return err
}
gid, err := strconv.Atoi(unprivilegedUser.Gid)
if err != nil {
return err
}
cmd.SysProcAttr = &syscall.SysProcAttr{
Credential: &syscall.Credential{
Uid: uint32(uid),
Gid: uint32(gid),
},
Setsid: true,
}
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if err := cmd.Start(); err != nil {
return err
}
err = ioutil.WriteFile(".pid", []byte(strconv.Itoa(cmd.Process.Pid)), 0644)
if err != nil {
panic(err)
}
cmd.Process.Release()
os.Exit(0)
return nil /* unreachable */
} else {
return nil
}
}
func havePrivileges() bool {
return os.Getuid() == 0
}