public void init(boolean forEncryption, CipherParameters params) throws IllegalArgumentException {
this.forEncryption = forEncryption;
CipherParameters cipherParameters;
if (params instanceof AEADParameters) {
AEADParameters param = (AEADParameters) params;
nonce = param.getNonce();
initialAssociatedText = param.getAssociatedText();
macSize = param.getMacSize() / 8;
cipherParameters = param.getKey();
} else if (params instanceof ParametersWithIV) {
ParametersWithIV param = (ParametersWithIV) params;
nonce = param.getIV();
initialAssociatedText = null;
macSize = macBlock.length / 2;
cipherParameters = param.getParameters();
} else {
throw new IllegalArgumentException("invalid parameters passed to CCM");
}
// NOTE: Very basic support for key re-use, but no performance gain from it
if (cipherParameters != null) {
keyParam = cipherParameters;
}
if (nonce == null || nonce.length < 7 || nonce.length > 13) {
throw new IllegalArgumentException("nonce must have length from 7 to 13 octets");
}
reset();
}
protected byte[] engineGetIV() {
return (ivParam != null) ? ivParam.getIV() : null;
}