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
47static void adjust(char[HEXKEYBYTES + 1], char *);
48static void getseed(char *, int, unsigned char *);
49
50/*
51 * Generate a seed
52 */
53static void
54getseed(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 */
66void
67genkeys(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 */
110static void
111adjust(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