forked from intelsdi-x/snap
-
Notifications
You must be signed in to change notification settings - Fork 0
/
encrypter.go
129 lines (109 loc) · 2.62 KB
/
encrypter.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
/*
http://www.apache.org/licenses/LICENSE-2.0.txt
Copyright 2015 Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package encrypter
import (
"crypto/aes"
"crypto/cipher"
"crypto/md5"
"crypto/rand"
"crypto/rsa"
"errors"
"hash"
"io"
"io/ioutil"
)
var ErrKeyNotValid = errors.New("given key length is invalid. did you set it?")
const (
nonceSize = 12
keySize = 32
)
func GenerateKey() ([]byte, error) {
key := make([]byte, keySize)
_, err := io.ReadFull(rand.Reader, key)
if err != nil {
return nil, err
}
return key, nil
}
type Encrypter struct {
Key []byte
rsaPublic *rsa.PublicKey
rsaPrivate *rsa.PrivateKey
md5 hash.Hash
}
func New(pub *rsa.PublicKey, priv *rsa.PrivateKey) *Encrypter {
return &Encrypter{
rsaPublic: pub,
rsaPrivate: priv,
md5: md5.New(),
}
}
func (e *Encrypter) Encrypt(in io.Reader) ([]byte, error) {
if len(e.Key) < keySize {
return nil, ErrKeyNotValid
}
bytes, err := ioutil.ReadAll(in)
if err != nil {
return nil, err
}
c, err := aes.NewCipher(e.Key)
if err != nil {
return nil, err
}
gcm, err := cipher.NewGCM(c)
if err != nil {
return nil, err
}
nonce, err := generateNonce()
if err != nil {
return nil, err
}
return gcm.Seal(nonce, nonce, bytes, nil), nil
}
func (e *Encrypter) Decrypt(in io.Reader) ([]byte, error) {
if len(e.Key) < keySize {
return nil, ErrKeyNotValid
}
bytes, err := ioutil.ReadAll(in)
if err != nil {
return nil, err
}
c, err := aes.NewCipher(e.Key)
if err != nil {
return nil, err
}
gcm, err := cipher.NewGCM(c)
if err != nil {
return nil, err
}
nonce := bytes[:nonceSize]
return gcm.Open(nil, nonce, bytes[nonceSize:], nil)
}
func (e *Encrypter) EncryptKey() ([]byte, error) {
if len(e.Key) != keySize {
return nil, ErrKeyNotValid
}
return rsa.EncryptOAEP(e.md5, rand.Reader, e.rsaPublic, e.Key, []byte(""))
}
func (e *Encrypter) DecryptKey(in []byte) ([]byte, error) {
return rsa.DecryptOAEP(e.md5, rand.Reader, e.rsaPrivate, in, []byte(""))
}
func generateNonce() ([]byte, error) {
nonce := make([]byte, nonceSize)
_, err := io.ReadFull(rand.Reader, nonce)
if err != nil {
return nil, err
}
return nonce, nil
}