// internal implementation of translateKey() for public keys. See JCA doc
private PublicKey translatePublicKey(PublicKey key) throws InvalidKeyException {
if (key instanceof RSAPublicKey) {
if (key instanceof RSAPublicKeyImpl) {
return key;
}
RSAPublicKey rsaKey = (RSAPublicKey) key;
try {
return new RSAPublicKeyImpl(rsaKey.getModulus(), rsaKey.getPublicExponent());
} catch (RuntimeException e) {
// catch providers that incorrectly implement RSAPublicKey
throw new InvalidKeyException("Invalid key", e);
}
} else if ("X.509".equals(key.getFormat())) {
byte[] encoded = key.getEncoded();
return new RSAPublicKeyImpl(encoded);
} else {
throw new InvalidKeyException(
"Public keys must be instance " + "of RSAPublicKey or have X.509 encoding");
}
}
