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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 "des_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 DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
| long length, DES_key_schedule *schedule,
| DES_cblock *ivec, int *num, int enc)
| {
| register DES_LONG v0, v1;
| register long l = length;
| register int n = *num;
| DES_LONG ti[2];
| unsigned char *iv, c, cc;
|
| iv = &(*ivec)[0];
| if (enc) {
| while (l--) {
| if (n == 0) {
| c2l(iv, v0);
| ti[0] = v0;
| c2l(iv, v1);
| ti[1] = v1;
| DES_encrypt1(ti, schedule, DES_ENCRYPT);
| iv = &(*ivec)[0];
| v0 = ti[0];
| l2c(v0, iv);
| v0 = ti[1];
| l2c(v0, iv);
| iv = &(*ivec)[0];
| }
| c = *(in++) ^ iv[n];
| *(out++) = c;
| iv[n] = c;
| n = (n + 1) & 0x07;
| }
| } else {
| while (l--) {
| if (n == 0) {
| c2l(iv, v0);
| ti[0] = v0;
| c2l(iv, v1);
| ti[1] = v1;
| DES_encrypt1(ti, schedule, DES_ENCRYPT);
| iv = &(*ivec)[0];
| v0 = ti[0];
| l2c(v0, iv);
| v0 = ti[1];
| l2c(v0, iv);
| iv = &(*ivec)[0];
| }
| cc = *(in++);
| c = iv[n];
| iv[n] = cc;
| *(out++) = c ^ cc;
| n = (n + 1) & 0x07;
| }
| }
| v0 = v1 = ti[0] = ti[1] = c = cc = 0;
| *num = n;
| }
|
|
