xref: /openssl/crypto/des/fcrypt_b.c (revision 33388b44)
1 /*
2  * Copyright 1995-2020 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 /*
11  * DES low level APIs are deprecated for public use, but still ok for internal
12  * use.
13  */
14 #include "internal/deprecated.h"
15 
16 #include <stdio.h>
17 
18 #define DES_FCRYPT
19 #include "des_local.h"
20 #undef DES_FCRYPT
21 
22 #undef PERM_OP
23 #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
24         (b)^=(t),\
25         (a)^=((t)<<(n)))
26 
27 #undef HPERM_OP
28 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
29         (a)=(a)^(t)^(t>>(16-(n))))\
30 
fcrypt_body(DES_LONG * out,DES_key_schedule * ks,DES_LONG Eswap0,DES_LONG Eswap1)31 void fcrypt_body(DES_LONG *out, DES_key_schedule *ks, DES_LONG Eswap0,
32                  DES_LONG Eswap1)
33 {
34     register DES_LONG l, r, t, u;
35     register DES_LONG *s;
36     register int j;
37     register DES_LONG E0, E1;
38 
39     l = 0;
40     r = 0;
41 
42     s = (DES_LONG *)ks;
43     E0 = Eswap0;
44     E1 = Eswap1;
45 
46     for (j = 0; j < 25; j++) {
47         D_ENCRYPT(l, r, 0);     /* 1 */
48         D_ENCRYPT(r, l, 2);     /* 2 */
49         D_ENCRYPT(l, r, 4);     /* 3 */
50         D_ENCRYPT(r, l, 6);     /* 4 */
51         D_ENCRYPT(l, r, 8);     /* 5 */
52         D_ENCRYPT(r, l, 10);    /* 6 */
53         D_ENCRYPT(l, r, 12);    /* 7 */
54         D_ENCRYPT(r, l, 14);    /* 8 */
55         D_ENCRYPT(l, r, 16);    /* 9 */
56         D_ENCRYPT(r, l, 18);    /* 10 */
57         D_ENCRYPT(l, r, 20);    /* 11 */
58         D_ENCRYPT(r, l, 22);    /* 12 */
59         D_ENCRYPT(l, r, 24);    /* 13 */
60         D_ENCRYPT(r, l, 26);    /* 14 */
61         D_ENCRYPT(l, r, 28);    /* 15 */
62         D_ENCRYPT(r, l, 30);    /* 16 */
63         t = l;
64         l = r;
65         r = t;
66     }
67     l = ROTATE(l, 3) & 0xffffffffL;
68     r = ROTATE(r, 3) & 0xffffffffL;
69 
70     PERM_OP(l, r, t,  1, 0x55555555L);
71     PERM_OP(r, l, t,  8, 0x00ff00ffL);
72     PERM_OP(l, r, t,  2, 0x33333333L);
73     PERM_OP(r, l, t, 16, 0x0000ffffL);
74     PERM_OP(l, r, t,  4, 0x0f0f0f0fL);
75 
76     out[0] = r;
77     out[1] = l;
78 }
79