private byte[] getPublicKeyBytes(PublicKey publicKey)
throws IOException, InvalidKeySpecException, NoSuchAlgorithmException {
byte[] enc = publicKey.getEncoded();
ASN1InputStream ap = new ASN1InputStream(enc);
DERSequence der = (DERSequence) ap.readObject();
DERBitString key = (DERBitString) der.getObjectAt(1);
byte[] k = key.getBytes();
ap.close();
return k;
}
private EncodedKeySpec getSpec(byte[] encodedKey, PublicKey pub)
throws IOException, InvalidKeySpecException, NoSuchAlgorithmException {
byte[] encc = pub.getEncoded();
ASN1InputStream ap = new ASN1InputStream(encc);
DERSequence der = (DERSequence) ap.readObject();
DERSequence s1 = (DERSequence) der.getObjectAt(0);
DERBitString bit = new DERBitString(encodedKey);
DERSequence s2 = new DERSequence(new DERObject[] {s1, bit});
byte[] enc = s2.getEncoded();
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(enc);
ap.close();
return keySpec;
}