github.com/zmap/zcrypto@v0.0.0-20240512203510-0fef58d9a9db/x509/pkcs8.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package x509
     6  
     7  import (
     8  	"errors"
     9  	"fmt"
    10  
    11  	"github.com/zmap/zcrypto/encoding/asn1"
    12  	"github.com/zmap/zcrypto/x509/pkix"
    13  )
    14  
    15  // pkcs8 reflects an ASN.1, PKCS#8 PrivateKey. See
    16  // ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-8/pkcs-8v1_2.asn
    17  // and RFC 5208.
    18  type pkcs8 struct {
    19  	Version    int
    20  	Algo       pkix.AlgorithmIdentifier
    21  	PrivateKey []byte
    22  	// optional attributes omitted.
    23  }
    24  
    25  // ParsePKCS8PrivateKey parses an unencrypted, PKCS#8 private key.
    26  // See RFC 5208.
    27  func ParsePKCS8PrivateKey(der []byte) (key interface{}, err error) {
    28  	var privKey pkcs8
    29  	if _, err := asn1.Unmarshal(der, &privKey); err != nil {
    30  		return nil, err
    31  	}
    32  	switch {
    33  	case privKey.Algo.Algorithm.Equal(oidPublicKeyRSA):
    34  		key, err = ParsePKCS1PrivateKey(privKey.PrivateKey)
    35  		if err != nil {
    36  			return nil, errors.New("x509: failed to parse RSA private key embedded in PKCS#8: " + err.Error())
    37  		}
    38  		return key, nil
    39  
    40  	case privKey.Algo.Algorithm.Equal(oidPublicKeyECDSA):
    41  		bytes := privKey.Algo.Parameters.FullBytes
    42  		namedCurveOID := new(asn1.ObjectIdentifier)
    43  		if _, err := asn1.Unmarshal(bytes, namedCurveOID); err != nil {
    44  			namedCurveOID = nil
    45  		}
    46  		key, err = parseECPrivateKey(namedCurveOID, privKey.PrivateKey)
    47  		if err != nil {
    48  			return nil, errors.New("x509: failed to parse EC private key embedded in PKCS#8: " + err.Error())
    49  		}
    50  		return key, nil
    51  
    52  	default:
    53  		return nil, fmt.Errorf("x509: PKCS#8 wrapping contained private key with unknown algorithm: %v", privKey.Algo.Algorithm)
    54  	}
    55  }