Question

Is there a possibility to generate an java.security.cert.X509Certificate from an byte[]?

Answer 1

Sure.

The certificate objects can be created by an instance of CertificateFactory – in particular, one configured to create X509 certificates. This can be created like so:

CertificateFactory certFactory = CertificateFactory.getInstance("X.509");

Then you need to pass it an InputStream containing the bytes of the certificate. This can be achieved by wrapping your byte array in a ByteArrayInputStream:

InputStream in = new ByteArrayInputStream(bytes);
X509Certificate cert = (X509Certificate)certFactory.generateCertificate(in);