private void generator_init(String cipher) {
cipher_ctx = Util.getCipherByName(cipher);
output_buffer = new byte[cipher_ctx.getBlockSize() / 8];
counter = new byte[cipher_ctx.getBlockSize() / 8];
allZeroString = new byte[cipher_ctx.getBlockSize() / 8];
tmp = new byte[cipher_ctx.getKeySize() / 8];
fetch_counter = output_buffer.length;
}
private final void generateOutput() {
counterInc();
output_buffer = new byte[counter.length];
cipher_ctx.encipher(counter, output_buffer);
if (output_count++ > Pg) {
output_count = 0;
nextBytes(tmp);
rekey(tmp);
}
}
// @SuppressWarnings("rawtypes")
public static BlockCipher createCipher(String type, boolean encrypt, byte[] key, byte[] iv) {
try {
CipherEntry ce = getEntry(type);
Class<?> cc = Class.forName(ce.cipherClass);
BlockCipher bc = (BlockCipher) cc.newInstance();
if (type.endsWith("-cbc")) {
bc.init(encrypt, key);
return new CBCMode(bc, iv, encrypt);
} else if (type.endsWith("-ctr")) {
bc.init(true, key);
return new CTRMode(bc, iv, encrypt);
}
throw new IllegalArgumentException("Cannot instantiate " + type);
} catch (ClassNotFoundException e) {
throw new IllegalArgumentException("Cannot instantiate " + type, e);
} catch (InstantiationException e) {
throw new IllegalArgumentException("Cannot instantiate " + type, e);
} catch (IllegalAccessException e) {
throw new IllegalArgumentException("Cannot instantiate " + type, e);
}
}
private void rekey(byte[] key) {
cipher_ctx.initialize(key);
counter = new byte[allZeroString.length];
cipher_ctx.encipher(allZeroString, counter);
Arrays.fill(key, (byte) 0);
}
