1 /*	$OpenBSD: x99token.c,v 1.6 2003/06/13 17:27:41 millert Exp $	*/
2 
3 /*
4  * X9.9 calculator
5  * This software is provided AS IS with no express or implied warranty
6  * October 1995, Paul Borman <prb@krystal.com>
7  *
8  * Donated to the Public Domain by Paul Borman
9  */
10 #include <sys/param.h>
11 #include <sys/stat.h>
12 
13 #include <ctype.h>
14 #include <err.h>
15 #include <pwd.h>
16 #include <readpassphrase.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <unistd.h>
21 #include <des.h>
22 
23 #define	KEYFILE		".keyfile.des"
24 #define	HEXDIGITS	"0123456789abcdef"
25 #define	DECDIGITS	"0123456789012345"
26 
27 void predict(des_key_schedule, const char *, int);
28 
29 char *digits = HEXDIGITS;
30 extern char *__progname;
31 
32 int
main(int argc,char ** argv)33 main(int argc, char **argv)
34 {
35 	int i;
36 	char buf[256];
37 	des_key_schedule ks;
38 	des_cblock key;
39 	char _keyfile[MAXPATHLEN];
40 	char *keyfile = 0;
41 	FILE *fp;
42 	int init = 0;
43 	int hex = 1;
44 	int cnt = 1;
45 	unsigned int pin;
46 	struct passwd *pwd;
47 
48 	while ((i = getopt(argc, argv, "dk:in:")) != -1) {
49 		switch (i) {
50 		case 'k':
51 			keyfile = optarg;
52 			break;
53 		case 'i':
54 			init = 1;
55 			break;
56 		case 'd':
57 			hex = 0;
58 			break;
59 		case 'n':
60 			cnt = atoi(optarg);
61 			if (cnt <= 0)
62 				err(1, "invalid count: %s", optarg);
63 			break;
64 		default:
65 			fprintf(stderr, "usage: %s [-n cnt] [-h] [-k keyfile]\n"
66 			    "       %s -i [-k keyfile]\n", __progname,
67 			    __progname);
68 			exit(1);
69 		}
70 	}
71 
72 	if (!keyfile) {
73 		if ((pwd = getpwuid(getuid())) == NULL) {
74 			fprintf(stderr, "Say, just who are you, anyhow?\n");
75 			exit(1);
76 		}
77 		snprintf(_keyfile, sizeof(_keyfile), "%s/%s", pwd->pw_dir,
78 		    KEYFILE);
79 		keyfile = _keyfile;
80 	}
81 
82 	if (init)
83 		readpassphrase("Enter Key: ", buf, sizeof(buf), 0);
84 	else if ((fp = fopen(keyfile, "r")) == NULL)
85 		err(1, "unable to open %s", keyfile);
86 	else {
87 		if (fgets(buf, sizeof(buf), fp) == NULL) {
88 			fprintf(stderr, "No key in %s\n", keyfile);
89 			exit(1);
90 		}
91 		fclose(fp);
92 	}
93 
94 	memset(key, 0, sizeof(key));
95 	if (init && buf[3] == ' ') {
96 		char *b = buf;
97 		/* Assume octal input */
98 		for (i = 0; i < 8; ++i) {
99 			if (!*b)
100 				fprintf(stderr, "%s: invalid key\n", buf);
101 			while (isdigit(*b))
102 				key[i] = key[i] << 3 | (*b++ - '0');
103 			while (*b && !isdigit(*b))
104 				++b;
105 		}
106 	} else {
107 		for (i = 0; i < 16; ++i) {
108 			int d;
109 
110 			if (islower(buf[i]))
111 				buf[i] = toupper(buf[i]);
112 			if (buf[i] >= '0' && buf[i] <= '9')
113 				d = buf[i] - '0';
114 			else if (buf[i] >= 'A' && buf[i] <= 'F')
115 				d = buf[i] - 'A' + 10;
116 			else {
117 				fprintf(stderr, "invalid key: %s\n", buf);
118 				exit(1);
119 			}
120 			key[i>>1] |= d << ((i & 1) ? 0 : 4);
121 		}
122 	}
123 
124 	/* XXX - should warn on non-space or non-digit */
125 	readpassphrase("Enter Pin: ", buf, sizeof(buf), 0);
126 	for (i = 0, pin = 0; buf[i] && buf[i] != '\n'; ++i)
127 		if (isdigit(buf[i]))
128 			pin = pin * 16 + buf[i] - '0' + 1;
129 
130 	if ((pin & 0xffff0000) == 0)
131 		pin |= pin << 16;
132 
133 	for (i = 0; i < 8; ++i)
134 		key[0] ^= (pin >> ((i * 7) % 26)) & 0x7f;
135 
136 	if (init) {
137 		if ((fp = fopen(keyfile, "w")) == NULL)
138 			err(1, "could not open %s for writing", keyfile);
139 		fchmod(fileno(fp), 0600);
140 		for (i = 0; i < 8; ++i) {
141 			fprintf(fp, "%c", digits[(key[i]>>4)&0xf]);
142 			fprintf(fp, "%c", digits[(key[i]>>0)&0xf]);
143 		}
144 		fputc('\n', fp);
145 		fclose(fp);
146 		exit(0);
147 	}
148 
149 	des_fixup_key_parity(&key);
150 	des_key_sched(&key, ks);
151 
152 	buf[0] = '\0';
153 	readpassphrase("Enter challenge: ", buf, sizeof(buf), RPP_ECHO_ON);
154 	if (buf[0] == '\0')
155 		exit(0);
156 
157 	for (i = 0; i < 8; ++i)
158 		if (buf[i] == '\n')
159 			buf[i] = '\0';
160 
161 	if (!hex)
162 		digits = DECDIGITS;
163 
164 	predict(ks, buf, cnt);
165 
166 	memset(&ks, 0, sizeof(ks));
167 	memset(buf, 0, sizeof(buf));
168 
169 	exit(0);
170 }
171 
172 void
predict(des_key_schedule ks,const char * chal,int cnt)173 predict(des_key_schedule ks, const char *chal, int cnt)
174 {
175 	int i;
176 	des_cblock cb;
177 
178 	memcpy(&cb, chal, sizeof(cb));
179 	while (cnt-- > 0) {
180 		printf("%.8s: ", (char *)cb);
181 		des_ecb_encrypt(&cb, &cb, ks, DES_ENCRYPT);
182 		for (i = 0; i < 4; ++i) {
183 			printf("%c", digits[(cb[i]>>4) & 0xf]);
184 			printf("%c", digits[(cb[i]>>0) & 0xf]);
185 		}
186 		putchar('\n');
187 		for (i = 0; i < 8; ++i) {
188 			if ((cb[i] &= 0xf) > 9)
189 				cb[i] -= 10;
190 			cb[i] |= 0x30;
191 		}
192 	}
193 	memset(&cb, 0, sizeof(cb));
194 }
195