k3s/vendor/github.com/google/certificate-transparency-go/x509/pkcs8.go

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2019-01-12 04:58:27 +00:00
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"crypto/ecdsa"
"crypto/rsa"
"errors"
"fmt"
"github.com/google/certificate-transparency-go/asn1"
"github.com/google/certificate-transparency-go/x509/pkix"
)
// pkcs8 reflects an ASN.1, PKCS#8 PrivateKey. See
// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-8/pkcs-8v1_2.asn
// and RFC 5208.
type pkcs8 struct {
Version int
Algo pkix.AlgorithmIdentifier
PrivateKey []byte
// optional attributes omitted.
}
// ParsePKCS8PrivateKey parses an unencrypted, PKCS#8 private key.
// See RFC 5208.
func ParsePKCS8PrivateKey(der []byte) (key interface{}, err error) {
var privKey pkcs8
if _, err := asn1.Unmarshal(der, &privKey); err != nil {
return nil, err
}
switch {
case privKey.Algo.Algorithm.Equal(OIDPublicKeyRSA):
key, err = ParsePKCS1PrivateKey(privKey.PrivateKey)
if err != nil {
return nil, errors.New("x509: failed to parse RSA private key embedded in PKCS#8: " + err.Error())
}
return key, nil
case privKey.Algo.Algorithm.Equal(OIDPublicKeyECDSA):
bytes := privKey.Algo.Parameters.FullBytes
namedCurveOID := new(asn1.ObjectIdentifier)
if _, err := asn1.Unmarshal(bytes, namedCurveOID); err != nil {
namedCurveOID = nil
}
key, err = parseECPrivateKey(namedCurveOID, privKey.PrivateKey)
if err != nil {
return nil, errors.New("x509: failed to parse EC private key embedded in PKCS#8: " + err.Error())
}
return key, nil
default:
return nil, fmt.Errorf("x509: PKCS#8 wrapping contained private key with unknown algorithm: %v", privKey.Algo.Algorithm)
}
}
// MarshalPKCS8PrivateKey converts a private key to PKCS#8 encoded form.
// The following key types are supported: *rsa.PrivateKey, *ecdsa.PublicKey.
// Unsupported key types result in an error.
//
// See RFC 5208.
func MarshalPKCS8PrivateKey(key interface{}) ([]byte, error) {
var privKey pkcs8
switch k := key.(type) {
case *rsa.PrivateKey:
privKey.Algo = pkix.AlgorithmIdentifier{
Algorithm: OIDPublicKeyRSA,
Parameters: asn1.NullRawValue,
}
privKey.PrivateKey = MarshalPKCS1PrivateKey(k)
case *ecdsa.PrivateKey:
oid, ok := OIDFromNamedCurve(k.Curve)
if !ok {
return nil, errors.New("x509: unknown curve while marshalling to PKCS#8")
}
oidBytes, err := asn1.Marshal(oid)
if err != nil {
return nil, errors.New("x509: failed to marshal curve OID: " + err.Error())
}
privKey.Algo = pkix.AlgorithmIdentifier{
Algorithm: OIDPublicKeyECDSA,
Parameters: asn1.RawValue{
FullBytes: oidBytes,
},
}
if privKey.PrivateKey, err = marshalECPrivateKeyWithOID(k, nil); err != nil {
return nil, errors.New("x509: failed to marshal EC private key while building PKCS#8: " + err.Error())
}
default:
return nil, fmt.Errorf("x509: unknown key type while marshalling PKCS#8: %T", key)
}
return asn1.Marshal(privKey)
}