freebsd-skq/crypto/cast/c_ofb64.c
2015-03-20 15:28:40 +00:00

111 lines
4.3 KiB
C

/* crypto/cast/c_ofb64.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <openssl/cast.h>
#include "cast_lcl.h"
/*
* The input and output encrypted as though 64bit ofb 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_ofb64_encrypt(const unsigned char *in, unsigned char *out,
long length, const CAST_KEY *schedule,
unsigned char *ivec, int *num)
{
register CAST_LONG v0, v1, t;
register int n = *num;
register long l = length;
unsigned char d[8];
register char *dp;
CAST_LONG ti[2];
unsigned char *iv;
int save = 0;
iv = ivec;
n2l(iv, v0);
n2l(iv, v1);
ti[0] = v0;
ti[1] = v1;
dp = (char *)d;
l2n(v0, dp);
l2n(v1, dp);
while (l--) {
if (n == 0) {
CAST_encrypt((CAST_LONG *)ti, schedule);
dp = (char *)d;
t = ti[0];
l2n(t, dp);
t = ti[1];
l2n(t, dp);
save++;
}
*(out++) = *(in++) ^ d[n];
n = (n + 1) & 0x07;
}
if (save) {
v0 = ti[0];
v1 = ti[1];
iv = ivec;
l2n(v0, iv);
l2n(v1, iv);
}
t = v0 = v1 = ti[0] = ti[1] = 0;
*num = n;
}