Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
#include <u.h>
2 
#include <libc.h>
3 
#include <bio.h>
4 
#include "authcmdlib.h"
5 
 
6 
/*
7 
 * compute the key verification checksum
8 
 */
9 
void
10 
checksum(char key[], char csum[]) {
11 
	uchar buf[8];
12 
 
13 
	memset(buf, 0, 8);
14 
	encrypt(key, buf, 8);
15 
	sprint(csum, "C %.2ux%.2ux%.2ux%.2ux", buf[0], buf[1], buf[2], buf[3]);
16 
}
17 
 
18 
/*
19 
 * compute the proper response.  We encrypt the ascii of
20 
 * challenge number, with trailing binary zero fill.
21 
 * This process was derived empirically.
22 
 * this was copied from inet's guard.
23 
 */
24 
char *
25 
netresp(char *key, long chal, char *answer)
26 
{
27 
	uchar buf[8];
28 
 
29 
	memset(buf, 0, 8);
30 
	snprint((char *)buf, sizeof buf, "%lud", chal);
31 
	if(encrypt(key, buf, 8) < 0)
32 
		error("can't encrypt response");
33 
	chal = (buf[0]<<24)+(buf[1]<<16)+(buf[2]<<8)+buf[3];
34 
	sprint(answer, "%.8lux", chal);
35 
 
36 
	return answer;
37 
}
38 
 
39 
char *
40 
netdecimal(char *answer)
41 
{
42 
	int i;
43 
 
44 
	for(i = 0; answer[i]; i++)
45 
		switch(answer[i]){
46 
		case 'a': case 'b': case 'c':
47 
			answer[i] = '2';
48 
			break;
49 
		case 'd': case 'e': case 'f':
50 
			answer[i] = '3';
51 
			break;
52 
		}
53 
	return answer;
54 
}
55 
 
56 
int
57 
netcheck(void *key, long chal, char *response)
58 
{
59 
	char answer[32], *p;
60 
	int i;
61 
 
62 
	if(smartcheck(key, chal, response))
63 
		return 1;
64 
 
65 
	if(p = strchr(response, '\n'))
66 
		*p = '\0';
67 
	netresp(key, chal, answer);
68 
 
69 
	/*
70 
	 * check for hex response -- securenet mode 1 or 5
71 
	 */
72 
	for(i = 0; response[i]; i++)
73 
		if(response[i] >= 'A' && response[i] <= 'Z')
74 
			response[i] -= 'A' - 'a';
75 
	if(strcmp(answer, response) == 0)
76 
		return 1;
77 
 
78 
	/*
79 
	 * check for decimal response -- securenet mode 0 or 4
80 
	 */
81 
	return strcmp(netdecimal(answer), response) == 0;
82 
}
83 
 
84 
int
85 
smartcheck(void *key, long chal, char *response)
86 
{
87 
	uchar buf[2*8];
88 
	int i, c, cslo, cshi;
89 
 
90 
	snprint((char*)buf, sizeof buf, "%lud        ", chal);
91 
	cslo = 0x52;
92 
	cshi = cslo;
93 
	for(i = 0; i < 8; i++){
94 
		c = buf[i];
95 
		if(c >= '0' && c <= '9')
96 
			c -= '0';
97 
		cslo += c;
98 
		if(cslo > 0xff)
99 
			cslo -= 0xff;
100 
		cshi += cslo;
101 
		if(cshi > 0xff)
102 
			cshi -= 0xff;
103 
		buf[i] = c | (cshi & 0xf0);
104 
	}
105 
 
106 
	encrypt(key, buf, 8);
107 
	for(i = 0; i < 8; i++)
108 
		if(response[i] != buf[i] % 10 + '0')
109 
			return 0;
110 
	return 1;
111 
}