ncbc_enc.c revision 55714 
1/* crypto/des/ncbc_enc.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include "des_locl.h"
60
61#ifdef CBC_ENC_C__DONT_UPDATE_IV
62void des_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
63	     des_key_schedule schedule, des_cblock *ivec, int enc)
64#else
65void des_ncbc_encrypt(const unsigned char *in, unsigned char *out, long length,
66	     des_key_schedule schedule, des_cblock *ivec, int enc)
67#endif
68	{
69	register DES_LONG tin0,tin1;
70	register DES_LONG tout0,tout1,xor0,xor1;
71	register long l=length;
72	DES_LONG tin[2];
73	unsigned char *iv;
74
75	iv = &(*ivec)[0];
76
77	if (enc)
78		{
79		c2l(iv,tout0);
80		c2l(iv,tout1);
81		for (l-=8; l>=0; l-=8)
82			{
83			c2l(in,tin0);
84			c2l(in,tin1);
85			tin0^=tout0; tin[0]=tin0;
86			tin1^=tout1; tin[1]=tin1;
87			des_encrypt((DES_LONG *)tin,schedule,DES_ENCRYPT);
88			tout0=tin[0]; l2c(tout0,out);
89			tout1=tin[1]; l2c(tout1,out);
90			}
91		if (l != -8)
92			{
93			c2ln(in,tin0,tin1,l+8);
94			tin0^=tout0; tin[0]=tin0;
95			tin1^=tout1; tin[1]=tin1;
96			des_encrypt((DES_LONG *)tin,schedule,DES_ENCRYPT);
97			tout0=tin[0]; l2c(tout0,out);
98			tout1=tin[1]; l2c(tout1,out);
99			}
100#ifndef CBC_ENC_C__DONT_UPDATE_IV
101		iv = &(*ivec)[0];
102		l2c(tout0,iv);
103		l2c(tout1,iv);
104#endif
105		}
106	else
107		{
108		c2l(iv,xor0);
109		c2l(iv,xor1);
110		for (l-=8; l>=0; l-=8)
111			{
112			c2l(in,tin0); tin[0]=tin0;
113			c2l(in,tin1); tin[1]=tin1;
114			des_encrypt((DES_LONG *)tin,schedule,DES_DECRYPT);
115			tout0=tin[0]^xor0;
116			tout1=tin[1]^xor1;
117			l2c(tout0,out);
118			l2c(tout1,out);
119			xor0=tin0;
120			xor1=tin1;
121			}
122		if (l != -8)
123			{
124			c2l(in,tin0); tin[0]=tin0;
125			c2l(in,tin1); tin[1]=tin1;
126			des_encrypt((DES_LONG *)tin,schedule,DES_DECRYPT);
127			tout0=tin[0]^xor0;
128			tout1=tin[1]^xor1;
129			l2cn(tout0,tout1,out,l+8);
130#ifndef CBC_ENC_C__DONT_UPDATE_IV
131			xor0=tin0;
132			xor1=tin1;
133#endif
134			}
135#ifndef CBC_ENC_C__DONT_UPDATE_IV
136		iv = &(*ivec)[0];
137		l2c(xor0,iv);
138		l2c(xor1,iv);
139#endif
140		}
141	tin0=tin1=tout0=tout1=xor0=xor1=0;
142	tin[0]=tin[1]=0;
143	}
144