1/*
2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <openssl/cast.h>
11#include "cast_local.h"
12#include "cast_s.h"
13
14#define CAST_exp(l,A,a,n) \
15 A[n/4]=l; \
16 a[n+3]=(l )&0xff; \
17 a[n+2]=(l>> 8)&0xff; \
18 a[n+1]=(l>>16)&0xff; \
19 a[n+0]=(l>>24)&0xff;
20
21#define S4 CAST_S_table4
22#define S5 CAST_S_table5
23#define S6 CAST_S_table6
24#define S7 CAST_S_table7
25
26void CAST_set_key(CAST_KEY *key, int len, const unsigned char *data)
27{
28 CAST_LONG x[16];
29 CAST_LONG z[16];
30 CAST_LONG k[32];
31 CAST_LONG X[4], Z[4];
32 CAST_LONG l, *K;
33 int i;
34
35 for (i = 0; i < 16; i++)
36 x[i] = 0;
37 if (len > 16)
38 len = 16;
39 for (i = 0; i < len; i++)
40 x[i] = data[i];
41 if (len <= 10)
42 key->short_key = 1;
43 else
44 key->short_key = 0;
45
46 K = &k[0];
47 X[0] = ((x[0] << 24) | (x[1] << 16) | (x[2] << 8) | x[3]) & 0xffffffffL;
48 X[1] = ((x[4] << 24) | (x[5] << 16) | (x[6] << 8) | x[7]) & 0xffffffffL;
49 X[2] = ((x[8] << 24) | (x[9] << 16) | (x[10] << 8) | x[11]) & 0xffffffffL;
50 X[3] =
51 ((x[12] << 24) | (x[13] << 16) | (x[14] << 8) | x[15]) & 0xffffffffL;
52
53 for (;;) {
54 l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
55 CAST_exp(l, Z, z, 0);
56 l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
57 CAST_exp(l, Z, z, 4);
58 l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
59 CAST_exp(l, Z, z, 8);
60 l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
61 CAST_exp(l, Z, z, 12);
62
63 K[0] = S4[z[8]] ^ S5[z[9]] ^ S6[z[7]] ^ S7[z[6]] ^ S4[z[2]];
64 K[1] = S4[z[10]] ^ S5[z[11]] ^ S6[z[5]] ^ S7[z[4]] ^ S5[z[6]];
65 K[2] = S4[z[12]] ^ S5[z[13]] ^ S6[z[3]] ^ S7[z[2]] ^ S6[z[9]];
66 K[3] = S4[z[14]] ^ S5[z[15]] ^ S6[z[1]] ^ S7[z[0]] ^ S7[z[12]];
67
68 l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
69 CAST_exp(l, X, x, 0);
70 l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
71 CAST_exp(l, X, x, 4);
72 l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
73 CAST_exp(l, X, x, 8);
74 l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
75 CAST_exp(l, X, x, 12);
76
77 K[4] = S4[x[3]] ^ S5[x[2]] ^ S6[x[12]] ^ S7[x[13]] ^ S4[x[8]];
78 K[5] = S4[x[1]] ^ S5[x[0]] ^ S6[x[14]] ^ S7[x[15]] ^ S5[x[13]];
79 K[6] = S4[x[7]] ^ S5[x[6]] ^ S6[x[8]] ^ S7[x[9]] ^ S6[x[3]];
80 K[7] = S4[x[5]] ^ S5[x[4]] ^ S6[x[10]] ^ S7[x[11]] ^ S7[x[7]];
81
82 l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
83 CAST_exp(l, Z, z, 0);
84 l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
85 CAST_exp(l, Z, z, 4);
86 l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
87 CAST_exp(l, Z, z, 8);
88 l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
89 CAST_exp(l, Z, z, 12);
90
91 K[8] = S4[z[3]] ^ S5[z[2]] ^ S6[z[12]] ^ S7[z[13]] ^ S4[z[9]];
92 K[9] = S4[z[1]] ^ S5[z[0]] ^ S6[z[14]] ^ S7[z[15]] ^ S5[z[12]];
93 K[10] = S4[z[7]] ^ S5[z[6]] ^ S6[z[8]] ^ S7[z[9]] ^ S6[z[2]];
94 K[11] = S4[z[5]] ^ S5[z[4]] ^ S6[z[10]] ^ S7[z[11]] ^ S7[z[6]];
95
96 l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
97 CAST_exp(l, X, x, 0);
98 l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
99 CAST_exp(l, X, x, 4);
100 l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
101 CAST_exp(l, X, x, 8);
102 l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
103 CAST_exp(l, X, x, 12);
104
105 K[12] = S4[x[8]] ^ S5[x[9]] ^ S6[x[7]] ^ S7[x[6]] ^ S4[x[3]];
106 K[13] = S4[x[10]] ^ S5[x[11]] ^ S6[x[5]] ^ S7[x[4]] ^ S5[x[7]];
107 K[14] = S4[x[12]] ^ S5[x[13]] ^ S6[x[3]] ^ S7[x[2]] ^ S6[x[8]];
108 K[15] = S4[x[14]] ^ S5[x[15]] ^ S6[x[1]] ^ S7[x[0]] ^ S7[x[13]];
109 if (K != k)
110 break;
111 K += 16;
112 }
113
114 for (i = 0; i < 16; i++) {
115 key->data[i * 2] = k[i];
116 key->data[i * 2 + 1] = ((k[i + 16]) + 16) & 0x1f;
117 }
118}
119