rc2skey.c

老外写的加密库cryptlib(版本3.1)

/* crypto/rc2/rc2_skey.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * 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 ([e-mail]).
 *
 * 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 ([e-mail])"
 *    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 ([e-mail])"
 *
 * 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.]
 */

#if defined( INC_ALL ) || defined( INC_CHILD )
  #include "osconfig.h"
  #include "rc2.h"
  #include "rc2locl.h"
#else
  #include "crypt/osconfig.h"
  #include "crypt/rc2.h"
  #include "crypt/rc2locl.h"
#endif /* Compiler-specific includes */

static unsigned char key_table[256]={
	0xd9,0x78,0xf9,0xc4,0x19,0xdd,0xb5,0xed,0x28,0xe9,0xfd,0x79,
	0x4a,0xa0,0xd8,0x9d,0xc6,0x7e,0x37,0x83,0x2b,0x76,0x53,0x8e,
	0x62,0x4c,0x64,0x88,0x44,0x8b,0xfb,0xa2,0x17,0x9a,0x59,0xf5,
	0x87,0xb3,0x4f,0x13,0x61,0x45,0x6d,0x8d,0x09,0x81,0x7d,0x32,
	0xbd,0x8f,0x40,0xeb,0x86,0xb7,0x7b,0x0b,0xf0,0x95,0x21,0x22,
	0x5c,0x6b,0x4e,0x82,0x54,0xd6,0x65,0x93,0xce,0x60,0xb2,0x1c,
	0x73,0x56,0xc0,0x14,0xa7,0x8c,0xf1,0xdc,0x12,0x75,0xca,0x1f,
	0x3b,0xbe,0xe4,0xd1,0x42,0x3d,0xd4,0x30,0xa3,0x3c,0xb6,0x26,
	0x6f,0xbf,0x0e,0xda,0x46,0x69,0x07,0x57,0x27,0xf2,0x1d,0x9b,
	0xbc,0x94,0x43,0x03,0xf8,0x11,0xc7,0xf6,0x90,0xef,0x3e,0xe7,
	0x06,0xc3,0xd5,0x2f,0xc8,0x66,0x1e,0xd7,0x08,0xe8,0xea,0xde,
	0x80,0x52,0xee,0xf7,0x84,0xaa,0x72,0xac,0x35,0x4d,0x6a,0x2a,
	0x96,0x1a,0xd2,0x71,0x5a,0x15,0x49,0x74,0x4b,0x9f,0xd0,0x5e,
	0x04,0x18,0xa4,0xec,0xc2,0xe0,0x41,0x6e,0x0f,0x51,0xcb,0xcc,
	0x24,0x91,0xaf,0x50,0xa1,0xf4,0x70,0x39,0x99,0x7c,0x3a,0x85,
	0x23,0xb8,0xb4,0x7a,0xfc,0x02,0x36,0x5b,0x25,0x55,0x97,0x31,
	0x2d,0x5d,0xfa,0x98,0xe3,0x8a,0x92,0xae,0x05,0xdf,0x29,0x10,
	0x67,0x6c,0xba,0xc9,0xd3,0x00,0xe6,0xcf,0xe1,0x9e,0xa8,0x2c,
	0x63,0x16,0x01,0x3f,0x58,0xe2,0x89,0xa9,0x0d,0x38,0x34,0x1b,
	0xab,0x33,0xff,0xb0,0xbb,0x48,0x0c,0x5f,0xb9,0xb1,0xcd,0x2e,
	0xc5,0xf3,0xdb,0x47,0xe5,0xa5,0x9c,0x77,0x0a,0xa6,0x20,0x68,
	0xfe,0x7f,0xc1,0xad,
	};

/* It has come to my attention that there are 2 versions of the RC2
 * key schedule.  One which is normal, and anther which has a hook to
 * use a reduced key length.
 * BSAFE uses the 'retarded' version.  What I previously shipped is
 * the same as specifying 1024 for the 'bits' parameter.  Bsafe uses
 * a version where the bits parameter is the same as len*8 */
void RC2_set_key(RC2_KEY *key, int len, const unsigned char *data, int bits)
	{
	int i,j;
	unsigned char *k;
	RC2_INT *ki;
	unsigned int c,d;

	k= (unsigned char *)&(key->data[0]);
	*k=0; /* for if there is a zero length key */

	if (len > 128) len=128;
	if (bits <= 0) bits=1024;
	if (bits > 1024) bits=1024;

	for (i=0; i<len; i++)
		k[i]=data[i];

	/* expand table */
	d=k[len-1];
	j=0;
	for (i=len; i < 128; i++,j++)
		{
		d=key_table[(k[j]+d)&0xff];
		k[i]=d;
		}

	/* hmm.... key reduction to 'bits' bits */

	j=(bits+7)>>3;
	i=128-j;
	c= (0xff>>(-bits & 0x07));

	d=key_table[k[i]&c];
	k[i]=d;
	while (i--)
		{
		d=key_table[k[i+j]^d];
		k[i]=d;
		}

	/* copy from bytes into RC2_INT's */
	ki= &(key->data[63]);
	for (i=127; i>=0; i-=2)
		*(ki--)=((k[i]<<8)|k[i-1])&0xffff;
	}