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
|
//
// Copyright 2021 The Sigstore Authors.
//
// 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 cryptoutils
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"github.com/secure-systems-lab/go-securesystemslib/encrypted"
)
const (
// PrivateKeyPEMType is the string "PRIVATE KEY" to be used during PEM encoding and decoding
PrivateKeyPEMType PEMType = "PRIVATE KEY"
// ECPrivateKeyPEMType is the string "EC PRIVATE KEY" used to parse SEC 1 EC private keys
ECPrivateKeyPEMType PEMType = "EC PRIVATE KEY"
// PKCS1PrivateKeyPEMType is the string "RSA PRIVATE KEY" used to parse PKCS#1-encoded private keys
PKCS1PrivateKeyPEMType PEMType = "RSA PRIVATE KEY"
encryptedCosignPrivateKeyPEMType PEMType = "ENCRYPTED COSIGN PRIVATE KEY"
// EncryptedSigstorePrivateKeyPEMType is the string "ENCRYPTED SIGSTORE PRIVATE KEY" to be used during PEM encoding and decoding
EncryptedSigstorePrivateKeyPEMType PEMType = "ENCRYPTED SIGSTORE PRIVATE KEY"
)
func pemEncodeKeyPair(priv crypto.PrivateKey, pub crypto.PublicKey, pf PassFunc) (privPEM, pubPEM []byte, err error) {
pubPEM, err = MarshalPublicKeyToPEM(pub)
if err != nil {
return nil, nil, err
}
derBytes, err := MarshalPrivateKeyToDER(priv)
if err != nil {
return nil, nil, err
}
if pf == nil {
return PEMEncode(PrivateKeyPEMType, derBytes), pubPEM, nil
}
password, err := pf(true)
if err != nil {
return nil, nil, err
}
if password == nil {
return PEMEncode(PrivateKeyPEMType, derBytes), pubPEM, nil
}
if derBytes, err = encrypted.Encrypt(derBytes, password); err != nil {
return nil, nil, err
}
return PEMEncode(EncryptedSigstorePrivateKeyPEMType, derBytes), pubPEM, nil
}
// GeneratePEMEncodedECDSAKeyPair generates an ECDSA keypair, optionally password encrypted using a provided PassFunc, and PEM encoded.
func GeneratePEMEncodedECDSAKeyPair(curve elliptic.Curve, pf PassFunc) (privPEM, pubPEM []byte, err error) {
priv, err := ecdsa.GenerateKey(curve, rand.Reader)
if err != nil {
return nil, nil, err
}
return pemEncodeKeyPair(priv, priv.Public(), pf)
}
// GeneratePEMEncodedRSAKeyPair generates an RSA keypair, optionally password encrypted using a provided PassFunc, and PEM encoded.
func GeneratePEMEncodedRSAKeyPair(keyLengthBits int, pf PassFunc) (privPEM, pubPEM []byte, err error) {
priv, err := rsa.GenerateKey(rand.Reader, keyLengthBits)
if err != nil {
return nil, nil, err
}
return pemEncodeKeyPair(priv, priv.Public(), pf)
}
// MarshalPrivateKeyToEncryptedDER marshals the private key and encrypts the DER-encoded value using the specified password function
func MarshalPrivateKeyToEncryptedDER(priv crypto.PrivateKey, pf PassFunc) ([]byte, error) {
derKey, err := MarshalPrivateKeyToDER(priv)
if err != nil {
return nil, err
}
password, err := pf(true)
if err != nil {
return nil, err
}
if password == nil {
return nil, errors.New("password was nil")
}
return encrypted.Encrypt(derKey, password)
}
// UnmarshalPEMToPrivateKey converts a PEM-encoded byte slice into a crypto.PrivateKey
func UnmarshalPEMToPrivateKey(pemBytes []byte, pf PassFunc) (crypto.PrivateKey, error) {
derBlock, _ := pem.Decode(pemBytes)
if derBlock == nil {
return nil, errors.New("PEM decoding failed")
}
switch derBlock.Type {
case string(PrivateKeyPEMType):
return x509.ParsePKCS8PrivateKey(derBlock.Bytes)
case string(PKCS1PrivateKeyPEMType):
return x509.ParsePKCS1PrivateKey(derBlock.Bytes)
case string(ECPrivateKeyPEMType):
return x509.ParseECPrivateKey(derBlock.Bytes)
case string(EncryptedSigstorePrivateKeyPEMType), string(encryptedCosignPrivateKeyPEMType):
derBytes := derBlock.Bytes
if pf != nil {
password, err := pf(false)
if err != nil {
return nil, err
}
if password != nil {
derBytes, err = encrypted.Decrypt(derBytes, password)
if err != nil {
return nil, err
}
}
}
return x509.ParsePKCS8PrivateKey(derBytes)
}
return nil, fmt.Errorf("unknown private key PEM file type: %v", derBlock.Type)
}
// MarshalPrivateKeyToDER converts a crypto.PrivateKey into a PKCS8 ASN.1 DER byte slice
func MarshalPrivateKeyToDER(priv crypto.PrivateKey) ([]byte, error) {
if priv == nil {
return nil, errors.New("empty key")
}
return x509.MarshalPKCS8PrivateKey(priv)
}
// MarshalPrivateKeyToPEM converts a crypto.PrivateKey into a PKCS#8 PEM-encoded byte slice
func MarshalPrivateKeyToPEM(priv crypto.PrivateKey) ([]byte, error) {
derBytes, err := MarshalPrivateKeyToDER(priv)
if err != nil {
return nil, err
}
return PEMEncode(PrivateKeyPEMType, derBytes), nil
}
|
