1package jwt
 2
 3import (
 4	"crypto"
 5	"crypto/ed25519"
 6	"crypto/x509"
 7	"encoding/pem"
 8	"errors"
 9)
10
11var (
12	ErrNotEdPrivateKey = errors.New("key is not a valid Ed25519 private key")
13	ErrNotEdPublicKey  = errors.New("key is not a valid Ed25519 public key")
14)
15
16// ParseEdPrivateKeyFromPEM parses a PEM-encoded Edwards curve private key
17func ParseEdPrivateKeyFromPEM(key []byte) (crypto.PrivateKey, error) {
18	var err error
19
20	// Parse PEM block
21	var block *pem.Block
22	if block, _ = pem.Decode(key); block == nil {
23		return nil, ErrKeyMustBePEMEncoded
24	}
25
26	// Parse the key
27	var parsedKey interface{}
28	if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {
29		return nil, err
30	}
31
32	var pkey ed25519.PrivateKey
33	var ok bool
34	if pkey, ok = parsedKey.(ed25519.PrivateKey); !ok {
35		return nil, ErrNotEdPrivateKey
36	}
37
38	return pkey, nil
39}
40
41// ParseEdPublicKeyFromPEM parses a PEM-encoded Edwards curve public key
42func ParseEdPublicKeyFromPEM(key []byte) (crypto.PublicKey, error) {
43	var err error
44
45	// Parse PEM block
46	var block *pem.Block
47	if block, _ = pem.Decode(key); block == nil {
48		return nil, ErrKeyMustBePEMEncoded
49	}
50
51	// Parse the key
52	var parsedKey interface{}
53	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
54		return nil, err
55	}
56
57	var pkey ed25519.PublicKey
58	var ok bool
59	if pkey, ok = parsedKey.(ed25519.PublicKey); !ok {
60		return nil, ErrNotEdPublicKey
61	}
62
63	return pkey, nil
64}