openssl/crypto/rc5/rc5_skey.c
2000-06-03 14:13:58 +00:00

114 lines
4.0 KiB
C

/* crypto/rc5/rc5_skey.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/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;
}
}