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/crypto.h>
60#include <openssl/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#ifdef OPENSSL_FIPS
66{
67    fips_cipher_abort(IDEA);
68    private_idea_set_encrypt_key(key, ks);
69}
70
71void private_idea_set_encrypt_key(const unsigned char *key,
72                                  IDEA_KEY_SCHEDULE *ks)
73#endif
74{
75    int i;
76    register IDEA_INT *kt, *kf, r0, r1, r2;
77
78    kt = &(ks->data[0][0]);
79    n2s(key, kt[0]);
80    n2s(key, kt[1]);
81    n2s(key, kt[2]);
82    n2s(key, kt[3]);
83    n2s(key, kt[4]);
84    n2s(key, kt[5]);
85    n2s(key, kt[6]);
86    n2s(key, kt[7]);
87
88    kf = kt;
89    kt += 8;
90    for (i = 0; i < 6; i++) {
91        r2 = kf[1];
92        r1 = kf[2];
93        *(kt++) = ((r2 << 9) | (r1 >> 7)) & 0xffff;
94        r0 = kf[3];
95        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
96        r1 = kf[4];
97        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
98        r0 = kf[5];
99        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
100        r1 = kf[6];
101        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
102        r0 = kf[7];
103        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;
104        r1 = kf[0];
105        if (i >= 5)
106            break;
107        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;
108        *(kt++) = ((r1 << 9) | (r2 >> 7)) & 0xffff;
109        kf += 8;
110    }
111}
112
113void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
114{
115    int r;
116    register IDEA_INT *fp, *tp, t;
117
118    tp = &(dk->data[0][0]);
119    fp = &(ek->data[8][0]);
120    for (r = 0; r < 9; r++) {
121        *(tp++) = inverse(fp[0]);
122        *(tp++) = ((int)(0x10000L - fp[2]) & 0xffff);
123        *(tp++) = ((int)(0x10000L - fp[1]) & 0xffff);
124        *(tp++) = inverse(fp[3]);
125        if (r == 8)
126            break;
127        fp -= 6;
128        *(tp++) = fp[4];
129        *(tp++) = fp[5];
130    }
131
132    tp = &(dk->data[0][0]);
133    t = tp[1];
134    tp[1] = tp[2];
135    tp[2] = t;
136
137    t = tp[49];
138    tp[49] = tp[50];
139    tp[50] = t;
140}
141
142/* taken directly from the 'paper' I'll have a look at it later */
143static IDEA_INT inverse(unsigned int xin)
144{
145    long n1, n2, q, r, b1, b2, t;
146
147    if (xin == 0)
148        b2 = 0;
149    else {
150        n1 = 0x10001;
151        n2 = xin;
152        b2 = 1;
153        b1 = 0;
154
155        do {
156            r = (n1 % n2);
157            q = (n1 - r) / n2;
158            if (r == 0) {
159                if (b2 < 0)
160                    b2 = 0x10001 + b2;
161            } else {
162                n1 = n2;
163                n2 = r;
164                t = b2;
165                b2 = b1 - q * b2;
166                b1 = t;
167            }
168        } while (r != 0);
169    }
170    return ((IDEA_INT) b2);
171}
172