example/main.go
func LoadPublicKey(data []byte) (interface{}, error) {
	input := data

	block, _ := pem.Decode(data)
	if block != nil {
		input = block.Bytes
	}

	// Try to load SubjectPublicKeyInfo
	pub, err0 := x509.ParsePKIXPublicKey(input)
	if err0 == nil {
		return pub, nil
	}

	cert, err1 := x509.ParseCertificate(input)
	if err1 == nil {
		return cert.PublicKey, nil
	}

	return nil, fmt.Errorf("square/go-jose: parse error, got '%s' and '%s'", err0, err1)
}
func LoadPublicKey(data []byte) (interface{}, error) {
	input := data

	block, _ := pem.Decode(data)
	if block != nil {
		input = block.Bytes
	}

	// Try to load SubjectPublicKeyInfo
	pub, err0 := x509.ParsePKIXPublicKey(input)
	if err0 == nil {
		return pub, nil
	}

	cert, err1 := x509.ParseCertificate(input)
	if err1 == nil {
		return cert.PublicKey, nil
	}

	return nil, fmt.Errorf("square/go-jose: parse error, got '%s' and '%s'", err0, err1)
}
// LoadPublicKey loads a public key from PEM/DER-encoded data.