-
Notifications
You must be signed in to change notification settings - Fork 1
/
backend.go
143 lines (108 loc) · 2.83 KB
/
backend.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
package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"fmt"
"io"
)
type Backend interface {
// Get a key value map under a given prefix
GetMap(string) (map[string][]byte, error)
// Set key value map under the given prefix
SetMap(string, map[string][]byte) error
// Delete all keys under the given prefix
DeleteMap(string) error
KeyExists(string) bool
}
func NewBackend(dcfg *DriverConfig) (Backend, error) {
var (
be Backend
err error
)
switch dcfg.BackendType {
case "consul":
be, err = NewConsulBackend(dcfg.BackendAddr, dcfg.Prefix)
default:
err = fmt.Errorf("backend not supported: %s", dcfg.BackendType)
}
// Enable encryption
if err == nil && len(dcfg.EncryptionKey) > 1 {
return &BasicEncryptedBackend{be: be, key: []byte(dcfg.EncryptionKey)}, nil
}
return be, err
}
type BasicEncryptedBackend struct {
be Backend
key []byte
}
// Get a key value map under a given prefix
func (ebe *BasicEncryptedBackend) GetMap(prefix string) (map[string][]byte, error) {
m, err := ebe.be.GetMap(prefix)
if err == nil {
for k, v := range m {
txt, err := ebe.decrypt(v)
if err != nil {
return nil, err
}
m[k] = txt
}
}
return m, err
}
// Set key value map under the given prefix
func (ebe *BasicEncryptedBackend) SetMap(prefix string, kmap map[string][]byte) error {
emap := map[string][]byte{}
for k, v := range kmap {
ct, err := ebe.encrypt(v)
if err != nil {
return err
}
emap[k] = ct
}
return ebe.be.SetMap(prefix, emap)
}
func (ebe *BasicEncryptedBackend) KeyExists(key string) bool {
return ebe.be.KeyExists(key)
}
// Delete all keys under the given prefix
func (ebe *BasicEncryptedBackend) DeleteMap(prefix string) error {
return ebe.be.DeleteMap(prefix)
}
func (ebe *BasicEncryptedBackend) encrypt(text []byte) ([]byte, error) {
return encrypt(ebe.key, text)
}
func (ebe *BasicEncryptedBackend) decrypt(ciphertext []byte) ([]byte, error) {
return decrypt(ebe.key, ciphertext)
}
func encrypt(key, text []byte) (ciphertext []byte, err error) {
var block cipher.Block
if block, err = aes.NewCipher(key); err != nil {
return nil, err
}
ciphertext = make([]byte, aes.BlockSize+len(string(text)))
// iv = initialization vector
iv := ciphertext[:aes.BlockSize]
if _, err = io.ReadFull(rand.Reader, iv); err != nil {
return
}
cfb := cipher.NewCFBEncrypter(block, iv)
cfb.XORKeyStream(ciphertext[aes.BlockSize:], text)
return
}
func decrypt(key, ciphertext []byte) (plaintext []byte, err error) {
var block cipher.Block
if block, err = aes.NewCipher(key); err != nil {
return
}
if len(ciphertext) < aes.BlockSize {
err = fmt.Errorf("ciphertext too short")
return
}
iv := ciphertext[:aes.BlockSize]
ciphertext = ciphertext[aes.BlockSize:]
cfb := cipher.NewCFBDecrypter(block, iv)
cfb.XORKeyStream(ciphertext, ciphertext)
plaintext = ciphertext
return
}