75 lines
2.0 KiB
C
75 lines
2.0 KiB
C
/*
|
|
* 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/cast.h>
|
|
#include "cast_local.h"
|
|
|
|
/*
|
|
* The input and output encrypted as though 64bit cfb mode is being used.
|
|
* The extra state information to record how much of the 64bit block we have
|
|
* used is contained in *num;
|
|
*/
|
|
|
|
void CAST_cfb64_encrypt(const unsigned char *in, unsigned char *out,
|
|
long length, const CAST_KEY *schedule,
|
|
unsigned char *ivec, int *num, int enc)
|
|
{
|
|
register CAST_LONG v0, v1, t;
|
|
register int n = *num;
|
|
register long l = length;
|
|
CAST_LONG ti[2];
|
|
unsigned char *iv, c, cc;
|
|
|
|
iv = ivec;
|
|
if (enc) {
|
|
while (l--) {
|
|
if (n == 0) {
|
|
n2l(iv, v0);
|
|
ti[0] = v0;
|
|
n2l(iv, v1);
|
|
ti[1] = v1;
|
|
CAST_encrypt((CAST_LONG *)ti, schedule);
|
|
iv = ivec;
|
|
t = ti[0];
|
|
l2n(t, iv);
|
|
t = ti[1];
|
|
l2n(t, iv);
|
|
iv = ivec;
|
|
}
|
|
c = *(in++) ^ iv[n];
|
|
*(out++) = c;
|
|
iv[n] = c;
|
|
n = (n + 1) & 0x07;
|
|
}
|
|
} else {
|
|
while (l--) {
|
|
if (n == 0) {
|
|
n2l(iv, v0);
|
|
ti[0] = v0;
|
|
n2l(iv, v1);
|
|
ti[1] = v1;
|
|
CAST_encrypt((CAST_LONG *)ti, schedule);
|
|
iv = ivec;
|
|
t = ti[0];
|
|
l2n(t, iv);
|
|
t = ti[1];
|
|
l2n(t, iv);
|
|
iv = ivec;
|
|
}
|
|
cc = *(in++);
|
|
c = iv[n];
|
|
iv[n] = cc;
|
|
*(out++) = c ^ cc;
|
|
n = (n + 1) & 0x07;
|
|
}
|
|
}
|
|
v0 = v1 = ti[0] = ti[1] = t = c = cc = 0;
|
|
*num = n;
|
|
}
|