xref: /freebsd/usr.bin/newkey/generic.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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 /*
32  * Copyright (C) 1986, Sun Microsystems, Inc.
33  */
34 
35 #include <sys/cdefs.h>
36 #include <sys/file.h>
37 
38 #include <rpc/rpc.h>
39 #include <rpc/key_prot.h>
40 
41 #include <mp.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 
45 #include "extern.h"
46 
47 static void adjust(char[HEXKEYBYTES + 1], char *);
48 static void getseed(char *, int, unsigned char *);
49 
50 /*
51  * Generate a seed
52  */
53 static void
54 getseed(char *seed, int seedsize, unsigned char *pass)
55 {
56 	int i;
57 
58 	for (i = 0; i < seedsize; i++) {
59 		seed[i] = (arc4random() & 0xff) ^ pass[i % 8];
60 	}
61 }
62 
63 /*
64  * Generate a random public/secret key pair
65  */
66 void
67 genkeys(char *public, char *secret, char *pass)
68 {
69 	unsigned int i;
70 
71 #   define BASEBITS (8*sizeof (short) - 1)
72 #	define BASE		(1 << BASEBITS)
73 
74 	MINT *pk = mp_itom(0);
75 	MINT *sk = mp_itom(0);
76 	MINT *tmp;
77 	MINT *base = mp_itom((short)BASE);
78 	MINT *root = mp_itom(PROOT);
79 	MINT *modulus = mp_xtom(HEXMODULUS);
80 	short r;
81 	unsigned short seed[KEYSIZE/BASEBITS + 1];
82 	char *xkey;
83 
84 	getseed((char *)seed, sizeof (seed), (u_char *)pass);
85 	for (i = 0; i < KEYSIZE/BASEBITS + 1; i++) {
86 		r = seed[i] % BASE;
87 		tmp = mp_itom(r);
88 		mp_mult(sk, base, sk);
89 		mp_madd(sk, tmp, sk);
90 		mp_mfree(tmp);
91 	}
92 	tmp = mp_itom(0);
93 	mp_mdiv(sk, modulus, tmp, sk);
94 	mp_mfree(tmp);
95 	mp_pow(root, sk, modulus, pk);
96 	xkey = mp_mtox(sk);
97 	adjust(secret, xkey);
98 	xkey = mp_mtox(pk);
99 	adjust(public, xkey);
100 	mp_mfree(sk);
101 	mp_mfree(base);
102 	mp_mfree(pk);
103 	mp_mfree(root);
104 	mp_mfree(modulus);
105 }
106 
107 /*
108  * Adjust the input key so that it is 0-filled on the left
109  */
110 static void
111 adjust(char keyout[HEXKEYBYTES+1], char *keyin)
112 {
113 	char *p;
114 	char *s;
115 
116 	for (p = keyin; *p; p++)
117 		;
118 	for (s = keyout + HEXKEYBYTES; p >= keyin; p--, s--) {
119 		*s = *p;
120 	}
121 	while (s >= keyout) {
122 		*s-- = '0';
123 	}
124 }
125