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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);
63 : 506 : 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 : 506 : kt= &(ks->data[0][0]);
69 : 506 : n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]);
70 : 506 : n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]);
71 : :
72 : 506 : kf=kt;
73 : 506 : kt+=8;
74 [ + - ]: 3036 : for (i=0; i<6; i++)
75 : : {
76 : 3036 : r2= kf[1];
77 : 3036 : r1= kf[2];
78 : 3036 : *(kt++)= ((r2<<9) | (r1>>7))&0xffff;
79 : 3036 : r0= kf[3];
80 : 3036 : *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
81 : 3036 : r1= kf[4];
82 : 3036 : *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
83 : 3036 : r0= kf[5];
84 : 3036 : *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
85 : 3036 : r1= kf[6];
86 : 3036 : *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
87 : 3036 : r0= kf[7];
88 : 3036 : *(kt++)= ((r1<<9) | (r0>>7))&0xffff;
89 : 3036 : r1= kf[0];
90 [ + + ]: 3036 : if (i >= 5) break;
91 : 2530 : *(kt++)= ((r0<<9) | (r1>>7))&0xffff;
92 : 2530 : *(kt++)= ((r1<<9) | (r2>>7))&0xffff;
93 : 2530 : kf+=8;
94 : : }
95 : 506 : }
96 : :
97 : 250 : 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 : 250 : tp= &(dk->data[0][0]);
103 : 250 : fp= &(ek->data[8][0]);
104 [ + - ]: 2250 : for (r=0; r<9; r++)
105 : : {
106 : 2250 : *(tp++)=inverse(fp[0]);
107 : 2250 : *(tp++)=((int)(0x10000L-fp[2])&0xffff);
108 : 2250 : *(tp++)=((int)(0x10000L-fp[1])&0xffff);
109 : 2250 : *(tp++)=inverse(fp[3]);
110 [ + + ]: 2250 : if (r == 8) break;
111 : 2000 : fp-=6;
112 : 2000 : *(tp++)=fp[4];
113 : 2000 : *(tp++)=fp[5];
114 : : }
115 : :
116 : 250 : tp= &(dk->data[0][0]);
117 : 250 : t=tp[1];
118 : 250 : tp[1]=tp[2];
119 : 250 : tp[2]=t;
120 : :
121 : 250 : t=tp[49];
122 : 250 : tp[49]=tp[50];
123 : 250 : tp[50]=t;
124 : 250 : }
125 : :
126 : : /* taken directly from the 'paper' I'll have a look at it later */
127 : 4500 : static IDEA_INT inverse(unsigned int xin)
128 : : {
129 : : long n1,n2,q,r,b1,b2,t;
130 : :
131 [ + - ]: 4500 : if (xin == 0)
132 : : b2=0;
133 : : else
134 : : {
135 : 4500 : n1=0x10001;
136 : 4500 : n2=xin;
137 : 4500 : b2=1;
138 : 4500 : b1=0;
139 : :
140 : : do {
141 : 44423 : r=(n1%n2);
142 : 44423 : q=(n1-r)/n2;
143 [ + + ]: 44423 : if (r == 0)
144 [ + + ]: 4500 : { if (b2 < 0) b2=0x10001+b2; }
145 : : else
146 : : {
147 : 39923 : n1=n2;
148 : 39923 : n2=r;
149 : 39923 : t=b2;
150 : 39923 : b2=b1-q*b2;
151 : 39923 : b1=t;
152 : : }
153 [ + + ]: 44423 : } while (r != 0);
154 : : }
155 : 4500 : return((IDEA_INT)b2);
156 : : }
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