DockerCLI/vendor/github.com/docker/notary/tuf/utils/pkcs8.go

342 lines
10 KiB
Go

// Package utils contains tuf related utility functions however this file is hard
// forked from https://github.com/youmark/pkcs8 package. It has been further modified
// based on the requirements of Notary. For converting keys into PKCS#8 format,
// original package expected *crypto.PrivateKey interface, which then type inferred
// to either *rsa.PrivateKey or *ecdsa.PrivateKey depending on the need and later
// converted to ASN.1 DER encoded form, this whole process was superfluous here as
// keys are already being kept in ASN.1 DER format wrapped in data.PrivateKey
// structure. With these changes, package has became tightly coupled with notary as
// most of the method signatures have been updated. Moreover support for ED25519
// keys has been added as well. License for original package is following:
//
// The MIT License (MIT)
//
// Copyright (c) 2014 youmark
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
package utils
import (
"crypto/aes"
"crypto/cipher"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/sha1"
"crypto/x509"
"crypto/x509/pkix"
"encoding/asn1"
"errors"
"fmt"
"golang.org/x/crypto/pbkdf2"
"github.com/docker/notary/tuf/data"
)
// Copy from crypto/x509
var (
oidPublicKeyRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
oidPublicKeyDSA = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1}
oidPublicKeyECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
// crypto/x509 doesn't have support for ED25519
// http://www.oid-info.com/get/1.3.6.1.4.1.11591.15.1
oidPublicKeyED25519 = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 11591, 15, 1}
)
// Copy from crypto/x509
var (
oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33}
oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
)
// Copy from crypto/x509
func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) {
switch curve {
case elliptic.P224():
return oidNamedCurveP224, true
case elliptic.P256():
return oidNamedCurveP256, true
case elliptic.P384():
return oidNamedCurveP384, true
case elliptic.P521():
return oidNamedCurveP521, true
}
return nil, false
}
// Unecrypted PKCS8
var (
oidPKCS5PBKDF2 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 5, 12}
oidPBES2 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 5, 13}
oidAES256CBC = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 1, 42}
)
type ecPrivateKey struct {
Version int
PrivateKey []byte
NamedCurveOID asn1.ObjectIdentifier `asn1:"optional,explicit,tag:0"`
PublicKey asn1.BitString `asn1:"optional,explicit,tag:1"`
}
type privateKeyInfo struct {
Version int
PrivateKeyAlgorithm []asn1.ObjectIdentifier
PrivateKey []byte
}
// Encrypted PKCS8
type pbkdf2Params struct {
Salt []byte
IterationCount int
}
type pbkdf2Algorithms struct {
IDPBKDF2 asn1.ObjectIdentifier
PBKDF2Params pbkdf2Params
}
type pbkdf2Encs struct {
EncryAlgo asn1.ObjectIdentifier
IV []byte
}
type pbes2Params struct {
KeyDerivationFunc pbkdf2Algorithms
EncryptionScheme pbkdf2Encs
}
type pbes2Algorithms struct {
IDPBES2 asn1.ObjectIdentifier
PBES2Params pbes2Params
}
type encryptedPrivateKeyInfo struct {
EncryptionAlgorithm pbes2Algorithms
EncryptedData []byte
}
// pkcs8 reflects an ASN.1, PKCS#8 PrivateKey.
// copied from https://github.com/golang/go/blob/964639cc338db650ccadeafb7424bc8ebb2c0f6c/src/crypto/x509/pkcs8.go#L17
type pkcs8 struct {
Version int
Algo pkix.AlgorithmIdentifier
PrivateKey []byte
}
func parsePKCS8ToTufKey(der []byte) (data.PrivateKey, error) {
var key pkcs8
if _, err := asn1.Unmarshal(der, &key); err != nil {
if _, ok := err.(asn1.StructuralError); ok {
return nil, errors.New("could not decrypt private key")
}
return nil, err
}
if key.Algo.Algorithm.Equal(oidPublicKeyED25519) {
tufED25519PrivateKey, err := ED25519ToPrivateKey(key.PrivateKey)
if err != nil {
return nil, fmt.Errorf("could not convert ed25519.PrivateKey to data.PrivateKey: %v", err)
}
return tufED25519PrivateKey, nil
}
privKey, err := x509.ParsePKCS8PrivateKey(der)
if err != nil {
return nil, err
}
switch priv := privKey.(type) {
case *rsa.PrivateKey:
tufRSAPrivateKey, err := RSAToPrivateKey(priv)
if err != nil {
return nil, fmt.Errorf("could not convert rsa.PrivateKey to data.PrivateKey: %v", err)
}
return tufRSAPrivateKey, nil
case *ecdsa.PrivateKey:
tufECDSAPrivateKey, err := ECDSAToPrivateKey(priv)
if err != nil {
return nil, fmt.Errorf("could not convert ecdsa.PrivateKey to data.PrivateKey: %v", err)
}
return tufECDSAPrivateKey, nil
}
return nil, errors.New("unsupported key type")
}
// ParsePKCS8ToTufKey requires PKCS#8 key in DER format and returns data.PrivateKey
// Password should be provided in case of Encrypted PKCS#8 key, else it should be nil.
func ParsePKCS8ToTufKey(der []byte, password []byte) (data.PrivateKey, error) {
if password == nil {
return parsePKCS8ToTufKey(der)
}
var privKey encryptedPrivateKeyInfo
if _, err := asn1.Unmarshal(der, &privKey); err != nil {
return nil, errors.New("pkcs8: only PKCS #5 v2.0 supported")
}
if !privKey.EncryptionAlgorithm.IDPBES2.Equal(oidPBES2) {
return nil, errors.New("pkcs8: only PBES2 supported")
}
if !privKey.EncryptionAlgorithm.PBES2Params.KeyDerivationFunc.IDPBKDF2.Equal(oidPKCS5PBKDF2) {
return nil, errors.New("pkcs8: only PBKDF2 supported")
}
encParam := privKey.EncryptionAlgorithm.PBES2Params.EncryptionScheme
kdfParam := privKey.EncryptionAlgorithm.PBES2Params.KeyDerivationFunc.PBKDF2Params
switch {
case encParam.EncryAlgo.Equal(oidAES256CBC):
iv := encParam.IV
salt := kdfParam.Salt
iter := kdfParam.IterationCount
encryptedKey := privKey.EncryptedData
symkey := pbkdf2.Key(password, salt, iter, 32, sha1.New)
block, err := aes.NewCipher(symkey)
if err != nil {
return nil, err
}
mode := cipher.NewCBCDecrypter(block, iv)
mode.CryptBlocks(encryptedKey, encryptedKey)
// no need to explicitly remove padding, as ASN.1 unmarshalling will automatically discard it
key, err := parsePKCS8ToTufKey(encryptedKey)
if err != nil {
return nil, errors.New("pkcs8: incorrect password")
}
return key, nil
default:
return nil, errors.New("pkcs8: only AES-256-CBC supported")
}
}
func convertTUFKeyToPKCS8(priv data.PrivateKey) ([]byte, error) {
var pkey privateKeyInfo
switch priv.Algorithm() {
case data.RSAKey, data.RSAx509Key:
// Per RFC5958, if publicKey is present, then version is set to v2(1) else version is set to v1(0).
// But openssl set to v1 even publicKey is present
pkey.Version = 0
pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 1)
pkey.PrivateKeyAlgorithm[0] = oidPublicKeyRSA
pkey.PrivateKey = priv.Private()
case data.ECDSAKey, data.ECDSAx509Key:
// To extract Curve value, parsing ECDSA key to *ecdsa.PrivateKey
eckey, err := x509.ParseECPrivateKey(priv.Private())
if err != nil {
return nil, err
}
oidNamedCurve, ok := oidFromNamedCurve(eckey.Curve)
if !ok {
return nil, errors.New("pkcs8: unknown elliptic curve")
}
// Per RFC5958, if publicKey is present, then version is set to v2(1) else version is set to v1(0).
// But openssl set to v1 even publicKey is present
pkey.Version = 1
pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 2)
pkey.PrivateKeyAlgorithm[0] = oidPublicKeyECDSA
pkey.PrivateKeyAlgorithm[1] = oidNamedCurve
pkey.PrivateKey = priv.Private()
case data.ED25519Key:
pkey.Version = 0
pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 1)
pkey.PrivateKeyAlgorithm[0] = oidPublicKeyED25519
pkey.PrivateKey = priv.Private()
default:
return nil, fmt.Errorf("algorithm %s not supported", priv.Algorithm())
}
return asn1.Marshal(pkey)
}
func convertTUFKeyToPKCS8Encrypted(priv data.PrivateKey, password []byte) ([]byte, error) {
// Convert private key into PKCS8 format
pkey, err := convertTUFKeyToPKCS8(priv)
if err != nil {
return nil, err
}
// Calculate key from password based on PKCS5 algorithm
// Use 8 byte salt, 16 byte IV, and 2048 iteration
iter := 2048
salt := make([]byte, 8)
iv := make([]byte, 16)
_, err = rand.Reader.Read(salt)
if err != nil {
return nil, err
}
_, err = rand.Reader.Read(iv)
if err != nil {
return nil, err
}
key := pbkdf2.Key(password, salt, iter, 32, sha1.New)
// Use AES256-CBC mode, pad plaintext with PKCS5 padding scheme
padding := aes.BlockSize - len(pkey)%aes.BlockSize
if padding > 0 {
n := len(pkey)
pkey = append(pkey, make([]byte, padding)...)
for i := 0; i < padding; i++ {
pkey[n+i] = byte(padding)
}
}
encryptedKey := make([]byte, len(pkey))
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
mode := cipher.NewCBCEncrypter(block, iv)
mode.CryptBlocks(encryptedKey, pkey)
pbkdf2algo := pbkdf2Algorithms{oidPKCS5PBKDF2, pbkdf2Params{salt, iter}}
pbkdf2encs := pbkdf2Encs{oidAES256CBC, iv}
pbes2algo := pbes2Algorithms{oidPBES2, pbes2Params{pbkdf2algo, pbkdf2encs}}
encryptedPkey := encryptedPrivateKeyInfo{pbes2algo, encryptedKey}
return asn1.Marshal(encryptedPkey)
}
// ConvertTUFKeyToPKCS8 converts a private key (data.Private) to PKCS#8 and returns in DER format
// if password is not nil, it would convert the Private Key to Encrypted PKCS#8.
func ConvertTUFKeyToPKCS8(priv data.PrivateKey, password []byte) ([]byte, error) {
if password == nil {
return convertTUFKeyToPKCS8(priv)
}
return convertTUFKeyToPKCS8Encrypted(priv, password)
}