public IDEA(BigInteger keyInteger, BigInteger iv) {
this.keyInteger = keyInteger;
this.iv = iv;
BigInteger[] keyArray = Helper.extractValues(keyInteger, 8, 16);
encKeys = getEncryptionKeys(keyArray);
decKeys = getDecryptionKeys(encKeys);
}
public BigInteger[][] getEncryptionKeys(BigInteger[] keyArray) {
// String keyString
BigInteger[] outputArray = new BigInteger[52];
// BigInteger[] keyArray = Helper.stringToBigIntegerArray(keyString);
BigInteger key = Helper.bigIntegerArraySum(keyArray, 8);
BigInteger[] shortKeyArray = Helper.extractValues(key, 16, 8);
// get keys
int i = 0;
while (i != 52) {
for (int j = 0; j < shortKeyArray.length; j++) {
BigInteger tmp = shortKeyArray[j];
outputArray[i++] = tmp;
if (i == 52) {
break;
}
}
if (i != 52) {
key = Helper.shift(key, 16, 25);
shortKeyArray = Helper.extractValues(key, 16, 8);
}
}
// get as 2d array
BigInteger[][] nicerArray = new BigInteger[9][6];
int counter = 0;
for (int zeile = 0; zeile < nicerArray.length; zeile++) {
for (int spalte = 0; spalte < nicerArray[zeile].length; spalte++) {
nicerArray[zeile][spalte] = outputArray[counter++];
if (counter == 52) {
return nicerArray;
}
}
}
return nicerArray;
}
public BigInteger idea(BigInteger input, boolean isEncryption) {
// make 4*16bit block array
BigInteger[] messagePart = Helper.extractValues(input, 16, 4);
BigInteger[] key = null;
for (int round = 0; round < 9; round++) {
// keys based on encryption or decryption
if (isEncryption) {
key = encKeys[round];
} else {
key = decKeys[round];
}
// encryption/decryption
messagePart = feistelNetwork(messagePart, key, round);
}
// from 4*16bit block array to one biginteger
BigInteger output = Helper.bigIntegerArraySum(messagePart, 16);
return output;
}
