i_cfb64.c revision 225736 
1/* crypto/idea/i_cfb64.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 <openssl/idea.h>
60#include "idea_lcl.h"
61
62/* The input and output encrypted as though 64bit cfb mode is being
63 * used.  The extra state information to record how much of the
64 * 64bit block we have used is contained in *num;
65 */
66
67void idea_cfb64_encrypt(const unsigned char *in, unsigned char *out,
68			long length, IDEA_KEY_SCHEDULE *schedule,
69			unsigned char *ivec, int *num, int encrypt)
70	{
71	register unsigned long v0,v1,t;
72	register int n= *num;
73	register long l=length;
74	unsigned long ti[2];
75	unsigned char *iv,c,cc;
76
77	iv=(unsigned char *)ivec;
78	if (encrypt)
79		{
80		while (l--)
81			{
82			if (n == 0)
83				{
84				n2l(iv,v0); ti[0]=v0;
85				n2l(iv,v1); ti[1]=v1;
86				idea_encrypt((unsigned long *)ti,schedule);
87				iv=(unsigned char *)ivec;
88				t=ti[0]; l2n(t,iv);
89				t=ti[1]; l2n(t,iv);
90				iv=(unsigned char *)ivec;
91				}
92			c= *(in++)^iv[n];
93			*(out++)=c;
94			iv[n]=c;
95			n=(n+1)&0x07;
96			}
97		}
98	else
99		{
100		while (l--)
101			{
102			if (n == 0)
103				{
104				n2l(iv,v0); ti[0]=v0;
105				n2l(iv,v1); ti[1]=v1;
106				idea_encrypt((unsigned long *)ti,schedule);
107				iv=(unsigned char *)ivec;
108				t=ti[0]; l2n(t,iv);
109				t=ti[1]; l2n(t,iv);
110				iv=(unsigned char *)ivec;
111				}
112			cc= *(in++);
113			c=iv[n];
114			iv[n]=cc;
115			*(out++)=c^cc;
116			n=(n+1)&0x07;
117			}
118		}
119	v0=v1=ti[0]=ti[1]=t=c=cc=0;
120	*num=n;
121	}
122
123