public static XeCryptRc4State XeCryptRc4Key(byte[] key) {
var state = new XeCryptRc4State();
byte j, temp;
int i;
/* Initialize state with identity permutation */
for (i = 0; i < 256; i++) {
state.perm[i] = (byte)i;
}
state.index1 = 0;
state.index2 = 0;
/* Randomize the permutation using key data */
for (j = 0, i = 0; i < 256; i++) {
j += (byte)(state.perm[i] + key[i % key.Length]);
temp = state.perm[i];
state.perm[i] = state.perm[j];
state.perm[j] = temp;
}
return state;
}
public static XeCryptRc4State XeCryptRc4Key(byte[] key)
{
var state = new XeCryptRc4State();
byte j, temp;
int i;
/* Initialize state with identity permutation */
for (i = 0; i < 256; i++)
{
state.perm[i] = (byte)i;
}
state.index1 = 0;
state.index2 = 0;
/* Randomize the permutation using key data */
for (j = 0, i = 0; i < 256; i++)
{
j += (byte)(state.perm[i] + key[i % key.Length]);
temp = state.perm[i];
state.perm[i] = state.perm[j];
state.perm[j] = temp;
}
return(state);
}
public static void XeCryptRc4Ecb(XeCryptRc4State state, ref byte[] inOut, int inputOffset, int inputLength) {
int i;
byte j, temp;
for (i = 0; i < inputLength; i++) {
/* Update modification indicies */
state.index1++;
state.index2 += state.perm[state.index1];
/* Modify permutation */
temp = state.perm[state.index1];
state.perm[state.index1] = state.perm[state.index2];
state.perm[state.index2] = temp;
/* Encrypt/decrypt next byte */
j = (byte)(state.perm[state.index1] + state.perm[state.index2]);
inOut[inputOffset + i] ^= state.perm[j];
}
}
public static void XeCryptRc4Ecb(XeCryptRc4State state, ref byte[] inOut, int inputOffset, int inputLength)
{
int i;
byte j, temp;
for (i = 0; i < inputLength; i++)
{
/* Update modification indicies */
state.index1++;
state.index2 += state.perm[state.index1];
/* Modify permutation */
temp = state.perm[state.index1];
state.perm[state.index1] = state.perm[state.index2];
state.perm[state.index2] = temp;
/* Encrypt/decrypt next byte */
j = (byte)(state.perm[state.index1] + state.perm[state.index2]);
inOut[inputOffset + i] ^= state.perm[j];
}
}
