rc5_skey.c
1.52 KB
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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/rc5.h>
#include "rc5_locl.h"
void RC5_32_set_key(RC5_32_KEY *key, int len, const unsigned char *data,
int rounds)
{
RC5_32_INT L[64], l, ll, A, B, *S, k;
int i, j, m, c, t, ii, jj;
if ((rounds != RC5_16_ROUNDS) &&
(rounds != RC5_12_ROUNDS) && (rounds != RC5_8_ROUNDS))
rounds = RC5_16_ROUNDS;
key->rounds = rounds;
S = &(key->data[0]);
j = 0;
for (i = 0; i <= (len - 8); i += 8) {
c2l(data, l);
L[j++] = l;
c2l(data, l);
L[j++] = l;
}
ii = len - i;
if (ii) {
k = len & 0x07;
c2ln(data, l, ll, k);
L[j + 0] = l;
L[j + 1] = ll;
}
c = (len + 3) / 4;
t = (rounds + 1) * 2;
S[0] = RC5_32_P;
for (i = 1; i < t; i++)
S[i] = (S[i - 1] + RC5_32_Q) & RC5_32_MASK;
j = (t > c) ? t : c;
j *= 3;
ii = jj = 0;
A = B = 0;
for (i = 0; i < j; i++) {
k = (S[ii] + A + B) & RC5_32_MASK;
A = S[ii] = ROTATE_l32(k, 3);
m = (int)(A + B);
k = (L[jj] + A + B) & RC5_32_MASK;
B = L[jj] = ROTATE_l32(k, m);
if (++ii >= t)
ii = 0;
if (++jj >= c)
jj = 0;
}
}