1 /* crypto/idea/i_skey.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 static IDEA_INT inverse(unsigned int xin);
idea_set_encrypt_key(const unsigned char * key,IDEA_KEY_SCHEDULE * ks)63 void idea_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks)
64 {
65 int i;
66 register IDEA_INT *kt,*kf,r0,r1,r2;
67
68 kt= &(ks->data[0][0]);
69 n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]);
70 n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]);
71
72 kf=kt;
73 kt+=8;
74 for (i=0; i<6; i++)
75 {
76 r2= kf[1];
77 r1= kf[2];
78 *(kt++)= ((r2<<9) | (r1>>7))&0xffff;
79 r0= kf[3];
80 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
81 r1= kf[4];
82 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
83 r0= kf[5];
84 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
85 r1= kf[6];
86 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
87 r0= kf[7];
88 *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
89 r1= kf[0];
90 if (i >= 5) break;
91 *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
92 *(kt++)= ((r1<<9) | (r2>>7))&0xffff;
93 kf+=8;
94 }
95 }
96
idea_set_decrypt_key(IDEA_KEY_SCHEDULE * ek,IDEA_KEY_SCHEDULE * dk)97 void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
98 {
99 int r;
100 register IDEA_INT *fp,*tp,t;
101
102 tp= &(dk->data[0][0]);
103 fp= &(ek->data[8][0]);
104 for (r=0; r<9; r++)
105 {
106 *(tp++)=inverse(fp[0]);
107 *(tp++)=((int)(0x10000L-fp[2])&0xffff);
108 *(tp++)=((int)(0x10000L-fp[1])&0xffff);
109 *(tp++)=inverse(fp[3]);
110 if (r == 8) break;
111 fp-=6;
112 *(tp++)=fp[4];
113 *(tp++)=fp[5];
114 }
115
116 tp= &(dk->data[0][0]);
117 t=tp[1];
118 tp[1]=tp[2];
119 tp[2]=t;
120
121 t=tp[49];
122 tp[49]=tp[50];
123 tp[50]=t;
124 }
125
126 /* taken directly from the 'paper' I'll have a look at it later */
inverse(unsigned int xin)127 static IDEA_INT inverse(unsigned int xin)
128 {
129 long n1,n2,q,r,b1,b2,t;
130
131 if (xin == 0)
132 b2=0;
133 else
134 {
135 n1=0x10001;
136 n2=xin;
137 b2=1;
138 b1=0;
139
140 do {
141 r=(n1%n2);
142 q=(n1-r)/n2;
143 if (r == 0)
144 { if (b2 < 0) b2=0x10001+b2; }
145 else
146 {
147 n1=n2;
148 n2=r;
149 t=b2;
150 b2=b1-q*b2;
151 b1=t;
152 }
153 } while (r != 0);
154 }
155 return((IDEA_INT)b2);
156 }
157