Update EEBUS to use version 0.6 of EEBUS libs

charger/eebus/certificate.go

@@ -0,0 +1,77 @@
+package eebus
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+
+	"github.com/enbility/ship-go/cert"
+)
+
+// CreateCertificate returns a newly created EEBUS compatible certificate
+func CreateCertificate() (tls.Certificate, error) {
+	return cert.CreateCertificate("", EEBUSBrandName, "DE", EEBUSDeviceCode)
+}
+
+// pemBlockForKey marshals private key into pem block
+func pemBlockForKey(priv interface{}) (*pem.Block, error) {
+	switch k := priv.(type) {
+	case *rsa.PrivateKey:
+		return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}, nil
+	case *ecdsa.PrivateKey:
+		b, err := x509.MarshalECPrivateKey(k)
+		if err != nil {
+			return nil, fmt.Errorf("unable to marshal ECDSA private key: %w", err)
+		}
+		return &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}, nil
+	default:
+		return nil, errors.New("unknown private key type")
+	}
+}
+
+// GetX509KeyPair saves returns the cert and key string values
+func GetX509KeyPair(cert tls.Certificate) (string, string, error) {
+	var certValue, keyValue string
+
+	out := new(bytes.Buffer)
+	err := pem.Encode(out, &pem.Block{Type: "CERTIFICATE", Bytes: cert.Certificate[0]})
+	if err == nil {
+		certValue = out.String()
+	}
+
+	if len(certValue) > 0 {
+		var pb *pem.Block
+		if pb, err = pemBlockForKey(cert.PrivateKey); err == nil {
+			out.Reset()
+			err = pem.Encode(out, pb)
+		}
+	}
+
+	if err == nil {
+		keyValue = out.String()
+	}
+
+	return certValue, keyValue, err
+}
+
+// SkiFromX509 extracts SKI from certificate
+func skiFromX509(leaf *x509.Certificate) (string, error) {
+	if len(leaf.SubjectKeyId) == 0 {
+		return "", errors.New("missing SubjectKeyId")
+	}
+	return fmt.Sprintf("%0x", leaf.SubjectKeyId), nil
+}
+
+// SkiFromCert extracts SKI from certificate
+func SkiFromCert(cert tls.Certificate) (string, error) {
+	leaf, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		return "", errors.New("failed parsing certificate: " + err.Error())
+	}
+	return skiFromX509(leaf)
+}