1// Copyright 2014 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
5package internal
6
7import (
8	"crypto/rsa"
9	"crypto/x509"
10	"encoding/pem"
11	"errors"
12	"fmt"
13)
14
15// ParseKey converts the binary contents of a private key file
16// to an *rsa.PrivateKey. It detects whether the private key is in a
17// PEM container or not. If so, it extracts the the private key
18// from PEM container before conversion. It only supports PEM
19// containers with no passphrase.
20func ParseKey(key []byte) (*rsa.PrivateKey, error) {
21	block, _ := pem.Decode(key)
22	if block != nil {
23		key = block.Bytes
24	}
25	parsedKey, err := x509.ParsePKCS8PrivateKey(key)
26	if err != nil {
27		parsedKey, err = x509.ParsePKCS1PrivateKey(key)
28		if err != nil {
29			return nil, fmt.Errorf("private key should be a PEM or plain PKCS1 or PKCS8; parse error: %v", err)
30		}
31	}
32	parsed, ok := parsedKey.(*rsa.PrivateKey)
33	if !ok {
34		return nil, errors.New("private key is invalid")
35	}
36	return parsed, nil
37}
38