ecdsa_utils.go

package jwt

import (
"crypto/ecdsa"
"crypto/x509"
"encoding/pem"
"errors"
)

var (
ErrNotECPublicKey=errors.New("key is not a valid ECDSA public key")
ErrNotECPrivateKey=errors.New("key is not a valid ECDSA private key")
)

// ParseECPrivateKeyFromPEM parses a PEM encoded Elliptic Curve Private Key Structure
funcParseECPrivateKeyFromPEM(key []byte) (*ecdsa.PrivateKey, error) {
varerrerror

// Parse PEM block
varblock*pem.Block
ifblock, _=pem.Decode(key); block==nil {
returnnil, ErrKeyMustBePEMEncoded
 }

// Parse the key
varparsedKeyinterface{}
ifparsedKey, err=x509.ParseECPrivateKey(block.Bytes); err!=nil {
ifparsedKey, err=x509.ParsePKCS8PrivateKey(block.Bytes); err!=nil {
returnnil, err
 }
 }

varpkey*ecdsa.PrivateKey
varokbool
ifpkey, ok=parsedKey.(*ecdsa.PrivateKey); !ok {
returnnil, ErrNotECPrivateKey
 }

returnpkey, nil
}

// ParseECPublicKeyFromPEM parses a PEM encoded PKCS1 or PKCS8 public key
funcParseECPublicKeyFromPEM(key []byte) (*ecdsa.PublicKey, error) {
varerrerror

// Parse PEM block
varblock*pem.Block
ifblock, _=pem.Decode(key); block==nil {
returnnil, ErrKeyMustBePEMEncoded
 }

// Parse the key
varparsedKeyinterface{}
ifparsedKey, err=x509.ParsePKIXPublicKey(block.Bytes); err!=nil {
ifcert, err:=x509.ParseCertificate(block.Bytes); err==nil {
parsedKey=cert.PublicKey
 } else {
returnnil, err
 }
 }

varpkey*ecdsa.PublicKey
varokbool
ifpkey, ok=parsedKey.(*ecdsa.PublicKey); !ok {
returnnil, ErrNotECPublicKey
 }

returnpkey, nil
}