-
Notifications
You must be signed in to change notification settings - Fork 0
/
key.go
146 lines (121 loc) · 3.12 KB
/
key.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
package yckms
import (
"context"
"encoding/binary"
"errors"
"io"
"github.com/yandex-cloud/go-genproto/yandex/cloud/kms/v1"
ycsdk "github.com/yandex-cloud/go-sdk"
)
const (
magic = "yckms"
schemeVersion byte = 1
)
type YcSymmetricKeyInterface interface {
GetKey() []byte
Decrypt() error
GetEncryptedKey() []byte
ReadEncryptedKey(r io.Reader) error
CreateKey() error
}
type ycSymmetricKey struct {
keyID string
key []byte
encryptedKey []byte
sdk *ycsdk.SDK
}
func serializeEncryptedKey(encryptedKey []byte) []byte {
/*
magic value "yckms"
scheme version (current version is 1)
uint64 - encrypted key len
encrypted key ...
*/
encryptedKeyLen := make([]byte, 4)
binary.LittleEndian.PutUint32(encryptedKeyLen, uint32(len(encryptedKey)))
result := append([]byte(magic), schemeVersion)
result = append(result, encryptedKeyLen...)
return append(result, encryptedKey...)
}
func deserializeEncryptedKey(r io.Reader) ([]byte, error) {
magicSchemeBytes := make([]byte, len(magic)+1)
_, err := r.Read(magicSchemeBytes)
if err != nil {
return nil, err
}
if string(magicSchemeBytes[0:len(magic)]) != magic {
return nil, errors.New("YC KMS: invalid encrypted header format")
}
if schemeVersion != magicSchemeBytes[len(magic)] {
return nil, errors.New("YC KMS: scheme version is not supported")
}
encryptedKeyLenBytes := make([]byte, 4)
_, err = r.Read(encryptedKeyLenBytes)
if err != nil {
return nil, err
}
encryptedKeyLen := binary.LittleEndian.Uint32(encryptedKeyLenBytes)
/*
Sanity check
*/
if encryptedKeyLen > 4096 {
return nil, errors.New("YC KMS: invalid size of the encrypted key")
}
encryptedKey := make([]byte, encryptedKeyLen)
_, err = r.Read(encryptedKey)
if err != nil {
return nil, err
}
return encryptedKey, nil
}
func (key *ycSymmetricKey) GetKey() []byte {
return key.key
}
func (key *ycSymmetricKey) Decrypt() error {
ctx := context.Background()
rsp, err := key.sdk.KMSCrypto().SymmetricCrypto().Decrypt(ctx, &kms.SymmetricDecryptRequest{
KeyId: key.keyID,
AadContext: nil,
Ciphertext: key.encryptedKey,
})
if err != nil {
return err
}
key.key = rsp.Plaintext
return nil
}
func (key *ycSymmetricKey) GetEncryptedKey() []byte {
if key.encryptedKey != nil {
return serializeEncryptedKey(key.encryptedKey)
}
return nil
}
func (key *ycSymmetricKey) ReadEncryptedKey(r io.Reader) error {
encryptedKey, err := deserializeEncryptedKey(r)
if err == nil {
key.encryptedKey = encryptedKey
}
return err
}
func (key *ycSymmetricKey) CreateKey() error {
ctx := context.Background()
dataKeyResponse, err := key.sdk.KMSCrypto().SymmetricCrypto().GenerateDataKey(ctx, &kms.GenerateDataKeyRequest{
KeyId: key.keyID,
DataKeySpec: kms.SymmetricAlgorithm_AES_256,
SkipPlaintext: false,
})
if err != nil {
return err
}
key.encryptedKey = dataKeyResponse.DataKeyCiphertext
key.key = dataKeyResponse.DataKeyPlaintext
return nil
}
func YcSymmetricKeyFromKeyIDAndSdk(keyID string, sdk *ycsdk.SDK) YcSymmetricKeyInterface {
return &ycSymmetricKey{
keyID: keyID,
key: nil,
encryptedKey: nil,
sdk: sdk,
}
}