xref: /titanic_41/usr/src/lib/libcrypt/common/des_encrypt.c (revision 0bb073995ac5a95bd35f2dd790df1ea3d8c2d507)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #pragma weak _des_encrypt1 = des_encrypt1
33 
34 #include <sys/types.h>
35 
36 void
37 des_encrypt1(char *block, char *L, char *IP, char *R, char *preS, char *E,
38 	char KS[][48], char S[][64], char *f, char *tempL, char *P, char *FP)
39 {
40 /* EXPORT DELETE START */
41 	int	i;
42 	int	t, j, k;
43 	char	t2;
44 
45 	/*
46 	 * First, permute the bits in the input
47 	 */
48 	for (j = 0; j < 64; j++)
49 		L[j] = block[IP[j]-1];
50 	/*
51 	 * Perform an encryption operation 16 times.
52 	 */
53 	for (i = 0; i < 16; i++) {
54 		/*
55 		 * Save the R array,
56 		 * which will be the new L.
57 		 */
58 		for (j = 0; j < 32; j++)
59 			tempL[j] = R[j];
60 		/*
61 		 * Expand R to 48 bits using the E selector;
62 		 * exclusive-or with the current key bits.
63 		 */
64 		for (j = 0; j < 48; j++)
65 			preS[j] = R[E[j]-1] ^ KS[i][j];
66 		/*
67 		 * The pre-select bits are now considered
68 		 * in 8 groups of 6 bits each.
69 		 * The 8 selection functions map these
70 		 * 6-bit quantities into 4-bit quantities
71 		 * and the results permuted
72 		 * to make an f(R, K).
73 		 * The indexing into the selection functions
74 		 * is peculiar; it could be simplified by
75 		 * rewriting the tables.
76 		 */
77 		for (j = 0; j < 8; j++) {
78 			t = 6*j;
79 			k = S[j][(preS[t+0]<<5)+
80 			    (preS[t+1]<<3)+
81 			    (preS[t+2]<<2)+
82 			    (preS[t+3]<<1)+
83 			    (preS[t+4]<<0)+
84 			    (preS[t+5]<<4)];
85 			t = 4*j;
86 			f[t+0] = (k>>3)&01;
87 			f[t+1] = (k>>2)&01;
88 			f[t+2] = (k>>1)&01;
89 			f[t+3] = (k>>0)&01;
90 		}
91 		/*
92 		 * The new R is L ^ f(R, K).
93 		 * The f here has to be permuted first, though.
94 		 */
95 		for (j = 0; j < 32; j++)
96 			R[j] = L[j] ^ f[P[j]-1];
97 		/*
98 		 * Finally, the new L (the original R)
99 		 * is copied back.
100 		 */
101 		for (j = 0; j < 32; j++)
102 			L[j] = tempL[j];
103 	}
104 	/*
105 	 * The output L and R are reversed.
106 	 */
107 	for (j = 0; j < 32; j++) {
108 		t2 = L[j];
109 		L[j] = R[j];
110 		R[j] = t2;
111 	}
112 	/*
113 	 * The final output
114 	 * gets the inverse permutation of the very original.
115 	 */
116 	for (j = 0; j < 64; j++)
117 		block[j] = L[FP[j]-1];
118 /* EXPORT DELETE END */
119 }
120