Digest digest = new SHA1Digest();
byte[] resBuf = new byte[digest.getDigestSize()];
byte[] bytes = spki.getPublicKeyData().getBytes();
digest.update(bytes, 0, bytes.length);
digest.doFinal(resBuf, 0);
this.keyidentifier = new DEROctetString(resBuf);
this.certissuer = GeneralNames.getInstance(name.toASN1Object());
this.certserno = new DERInteger(serialNumber);
}