source: trunk/cscrypt/i_skey.c@ 3181

Last change on this file since 3181 was 3181, checked in by dingo35, 10 years ago

Adding threadsafety FIXMEs, feel free to join checking..

File size: 4.9 KB
Line 
1//FIXME Not checked on threadsafety yet; after checking please remove this line
2/* crypto/idea/i_skey.c */
3/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * All rights reserved.
5 *
6 * This package is an SSL implementation written
7 * by Eric Young (eay@cryptsoft.com).
8 * The implementation was written so as to conform with Netscapes SSL.
9 *
10 * This library is free for commercial and non-commercial use as long as
11 * the following conditions are aheared to. The following conditions
12 * apply to all code found in this distribution, be it the RC4, RSA,
13 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
14 * included with this distribution is covered by the same copyright terms
15 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 *
17 * Copyright remains Eric Young's, and as such any Copyright notices in
18 * the code are not to be removed.
19 * If this package is used in a product, Eric Young should be given attribution
20 * as the author of the parts of the library used.
21 * This can be in the form of a textual message at program startup or
22 * in documentation (online or textual) provided with the package.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the copyright
28 * notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in the
31 * documentation and/or other materials provided with the distribution.
32 * 3. All advertising materials mentioning features or use of this software
33 * must display the following acknowledgement:
34 * "This product includes cryptographic software written by
35 * Eric Young (eay@cryptsoft.com)"
36 * The word 'cryptographic' can be left out if the rouines from the library
37 * being used are not cryptographic related :-).
38 * 4. If you include any Windows specific code (or a derivative thereof) from
39 * the apps directory (application code) you must include an acknowledgement:
40 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 *
42 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
43 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
46 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 *
54 * The licence and distribution terms for any publically available version or
55 * derivative of this code cannot be changed. i.e. this code cannot simply be
56 * copied and put under another distribution licence
57 * [including the GNU Public Licence.]
58 */
59
60#include "idea.h"
61#include "idea_lcl.h"
62
63static IDEA_INT inverse(unsigned int xin);
64void idea_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks)
65 {
66 int i;
67 register IDEA_INT *kt,*kf,r0,r1,r2;
68
69 kt= &(ks->data[0][0]);
70 n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]);
71 n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]);
72
73 kf=kt;
74 kt+=8;
75 for (i=0; i<6; i++)
76 {
77 r2= kf[1];
78 r1= kf[2];
79 *(kt++)= ((r2<<9) | (r1>>7))&0xffff;
80 r0= kf[3];
81 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
82 r1= kf[4];
83 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
84 r0= kf[5];
85 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
86 r1= kf[6];
87 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
88 r0= kf[7];
89 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
90 r1= kf[0];
91 if (i >= 5) break;
92 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
93 *(kt++)= ((r1<<9) | (r2>>7))&0xffff;
94 kf+=8;
95 }
96 }
97
98void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
99 {
100 int r;
101 register IDEA_INT *fp,*tp,t;
102
103 tp= &(dk->data[0][0]);
104 fp= &(ek->data[8][0]);
105 for (r=0; r<9; r++)
106 {
107 *(tp++)=inverse(fp[0]);
108 *(tp++)=((int)(0x10000L-fp[2])&0xffff);
109 *(tp++)=((int)(0x10000L-fp[1])&0xffff);
110 *(tp++)=inverse(fp[3]);
111 if (r == 8) break;
112 fp-=6;
113 *(tp++)=fp[4];
114 *(tp++)=fp[5];
115 }
116
117 tp= &(dk->data[0][0]);
118 t=tp[1];
119 tp[1]=tp[2];
120 tp[2]=t;
121
122 t=tp[49];
123 tp[49]=tp[50];
124 tp[50]=t;
125 }
126
127/* taken directly from the 'paper' I'll have a look at it later */
128static IDEA_INT inverse(unsigned int xin)
129 {
130 long n1,n2,q,r,b1,b2,t;
131
132 if (xin == 0)
133 b2=0;
134 else
135 {
136 n1=0x10001;
137 n2=xin;
138 b2=1;
139 b1=0;
140
141 do {
142 r=(n1%n2);
143 q=(n1-r)/n2;
144 if (r == 0)
145 { if (b2 < 0) b2=0x10001+b2; }
146 else
147 {
148 n1=n2;
149 n2=r;
150 t=b2;
151 b2=b1-q*b2;
152 b1=t;
153 }
154 } while (r != 0);
155 }
156 return((IDEA_INT)b2);
157 }
Note: See TracBrowser for help on using the repository browser.