i_cfb64.c revision 68654 
1169092Sdeischen/* crypto/idea/i_cfb64.c */
2169092Sdeischen/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3169092Sdeischen * All rights reserved.
4156608Sdeischen *
5156608Sdeischen * This package is an SSL implementation written
6169092Sdeischen * by Eric Young (eay@cryptsoft.com).
7156608Sdeischen * The implementation was written so as to conform with Netscapes SSL.
8156608Sdeischen *
9156608Sdeischen * This library is free for commercial and non-commercial use as long as
10156608Sdeischen * the following conditions are aheared to.  The following conditions
11156608Sdeischen * apply to all code found in this distribution, be it the RC4, RSA,
12169092Sdeischen * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13156608Sdeischen * included with this distribution is covered by the same copyright terms
14156608Sdeischen * 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 * $FreeBSD: head/crypto/openssl/crypto/idea/i_cfb64.c 68654 2000-11-13 02:20:29Z kris $
58 */
59
60#include <openssl/idea.h>
61#include "idea_lcl.h"
62
63/* The input and output encrypted as though 64bit cfb mode is being
64 * used.  The extra state information to record how much of the
65 * 64bit block we have used is contained in *num;
66 */
67
68void idea_cfb64_encrypt(const unsigned char *in, unsigned char *out,
69			long length, IDEA_KEY_SCHEDULE *schedule,
70			unsigned char *ivec, int *num, int encrypt)
71	{
72	register unsigned long v0,v1,t;
73	register int n= *num;
74	register long l=length;
75	unsigned long ti[2];
76	unsigned char *iv,c,cc;
77
78	iv=(unsigned char *)ivec;
79	if (encrypt)
80		{
81		while (l--)
82			{
83			if (n == 0)
84				{
85				n2l(iv,v0); ti[0]=v0;
86				n2l(iv,v1); ti[1]=v1;
87				idea_encrypt((unsigned long *)ti,schedule);
88				iv=(unsigned char *)ivec;
89				t=ti[0]; l2n(t,iv);
90				t=ti[1]; l2n(t,iv);
91				iv=(unsigned char *)ivec;
92				}
93			c= *(in++)^iv[n];
94			*(out++)=c;
95			iv[n]=c;
96			n=(n+1)&0x07;
97			}
98		}
99	else
100		{
101		while (l--)
102			{
103			if (n == 0)
104				{
105				n2l(iv,v0); ti[0]=v0;
106				n2l(iv,v1); ti[1]=v1;
107				idea_encrypt((unsigned long *)ti,schedule);
108				iv=(unsigned char *)ivec;
109				t=ti[0]; l2n(t,iv);
110				t=ti[1]; l2n(t,iv);
111				iv=(unsigned char *)ivec;
112				}
113			cc= *(in++);
114			c=iv[n];
115			iv[n]=cc;
116			*(out++)=c^cc;
117			n=(n+1)&0x07;
118			}
119		}
120	v0=v1=ti[0]=ti[1]=t=c=cc=0;
121	*num=n;
122	}
123
124