xref: /freebsd/usr.bin/newkey/generic.c (revision ea906c4152774dff300bb26fbfc1e4188351c89a)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user or with the express written consent of
8  * Sun Microsystems, Inc.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 
31 #if !defined(lint) && defined(SCCSIDS)
32 #if 0
33 static char sccsid[] = "@(#)generic.c 1.2 91/03/11 Copyr 1986 Sun Micro";
34 #endif
35 #endif
36 
37 /*
38  * Copyright (C) 1986, Sun Microsystems, Inc.
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/file.h>
45 
46 #include <rpc/rpc.h>
47 #include <rpc/key_prot.h>
48 
49 #include <mp.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 
53 #include "extern.h"
54 
55 static void adjust(char[], char *);
56 static void getseed(char *, int, unsigned char *);
57 
58 /*
59  * Generate a seed
60  */
61 static void
62 getseed(char *seed, int seedsize, unsigned char *pass)
63 {
64 	int i;
65 
66 	for (i = 0; i < seedsize; i++) {
67 		seed[i] = (arc4random() & 0xff) ^ pass[i % 8];
68 	}
69 }
70 
71 /*
72  * Generate a random public/secret key pair
73  */
74 void
75 genkeys(char *public, char *secret, char *pass)
76 {
77 	unsigned int i;
78 
79 #   define BASEBITS (8*sizeof (short) - 1)
80 #	define BASE		(1 << BASEBITS)
81 
82 	MINT *pk = itom(0);
83 	MINT *sk = itom(0);
84 	MINT *tmp;
85 	MINT *base = itom(BASE);
86 	MINT *root = itom(PROOT);
87 	MINT *modulus = xtom(HEXMODULUS);
88 	short r;
89 	unsigned short seed[KEYSIZE/BASEBITS + 1];
90 	char *xkey;
91 
92 	getseed((char *)seed, sizeof (seed), (u_char *)pass);
93 	for (i = 0; i < KEYSIZE/BASEBITS + 1; i++) {
94 		r = seed[i] % BASE;
95 		tmp = itom(r);
96 		mult(sk, base, sk);
97 		madd(sk, tmp, sk);
98 		mfree(tmp);
99 	}
100 	tmp = itom(0);
101 	mdiv(sk, modulus, tmp, sk);
102 	mfree(tmp);
103 	pow(root, sk, modulus, pk);
104 	xkey = mtox(sk);
105 	adjust(secret, xkey);
106 	xkey = mtox(pk);
107 	adjust(public, xkey);
108 	mfree(sk);
109 	mfree(base);
110 	mfree(pk);
111 	mfree(root);
112 	mfree(modulus);
113 }
114 
115 /*
116  * Adjust the input key so that it is 0-filled on the left
117  */
118 static void
119 adjust(char keyout[HEXKEYBYTES+1], char *keyin)
120 {
121 	char *p;
122 	char *s;
123 
124 	for (p = keyin; *p; p++)
125 		;
126 	for (s = keyout + HEXKEYBYTES; p >= keyin; p--, s--) {
127 		*s = *p;
128 	}
129 	while (s >= keyout) {
130 		*s-- = '0';
131 	}
132 }
133