aboutsummaryrefslogtreecommitdiff
path: root/lib/libskey/skeylogin.c
blob: bc49cb715231abd0cbcb4da78b68b872cb0b5e63 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/*   Login code for S/KEY Authentication.  S/KEY is a trademark
 *   of Bellcore.
 *
 *   Mink is the former name of the S/KEY authentication system.
 *   Many references for mink  may still be found in this program.   */

#include <sys/param.h>
#ifdef	QUOTA
#include <sys/quota.h>
#endif
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>

 
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <errno.h>
#include "skey.h"

#define	KEYFILE	"/etc/skeykeys"

char *skipspace();
int skeylookup __ARGS((struct skey *mp,char *name));

#define setpriority(x,y,z)	/* nothing */

/* Issue a skey challenge for user 'name'. If successful,
 * fill in the caller's skey structure and return 0. If unsuccessful
 * (e.g., if name is unknown) return -1.
 *
 * The file read/write pointer is left at the start of the
 * record.
 */
int
getskeyprompt(mp,name,prompt)
struct skey *mp;
char *name;
char *prompt;
{
	int rval;

	sevenbit(name);
	rval = skeylookup(mp,name);
	strcpy(prompt,"s/key 55 latour1\n");
	switch(rval){
	case -1:	/* File error */
		return -1;
	case 0:		/* Lookup succeeded, return challenge */
		sprintf(prompt,"s/key %d %s\n",mp->n - 1,mp->seed);
		return 0;
	case 1:		/* User not found */
		fclose(mp->keyfile);
		return -1;
	}
	return -1;	/* Can't happen */
}	
/* Return  a skey challenge string for user 'name'. If successful,
 * fill in the caller's skey structure and return 0. If unsuccessful
 * (e.g., if name is unknown) return -1.
 *
 * The file read/write pointer is left at the start of the
 * record.
 */
int
skeychallenge(mp,name, ss)
struct skey *mp;
char *name;
char *ss;
{
	int rval;

	rval = skeylookup(mp,name);
	switch(rval){
	case -1:	/* File error */
		return -1;
	case 0:		/* Lookup succeeded, issue challenge */
                sprintf(ss, "s/key %d %s",mp->n - 1,mp->seed);
		return 0;
	case 1:		/* User not found */
		fclose(mp->keyfile);
		return -1;
	}
	return -1;	/* Can't happen */
}	

/* Find an entry in the One-time Password database.
 * Return codes:
 * -1: error in opening database
 *  0: entry found, file R/W pointer positioned at beginning of record
 *  1: entry not found, file R/W pointer positioned at EOF
 */
int
skeylookup(mp,name)
struct skey *mp;
char *name;
{
	int found;
	int len;
	long recstart;
	char *cp;
	struct stat statbuf;

	/* See if the KEYFILE exists, and create it if not */
	if(stat(KEYFILE,&statbuf) == -1 && errno == ENOENT){
		mp->keyfile = fopen(KEYFILE,"w+");
		(void) chmod(KEYFILE, 0644);
	} else {
		/* Otherwise open normally for update */
		mp->keyfile = fopen(KEYFILE,"r+");
	}
	if(mp->keyfile == NULL)
		return -1;

	/* Look up user name in database */
	len = strlen(name);
	if( len > 8 ) len = 8;		/*  Added 8/2/91  -  nmh */
	found = 0;
	while(!feof(mp->keyfile)){
		recstart = ftell(mp->keyfile);
		mp->recstart = recstart;
		if(fgets(mp->buf,sizeof(mp->buf),mp->keyfile) != mp->buf){
			break;
		}
		rip(mp->buf);
		if(mp->buf[0] == '#')
			continue;	/* Comment */
		if((mp->logname = strtok(mp->buf," \t")) == NULL)
			continue;
		if((cp = strtok(NULL," \t")) == NULL)
			continue;
		mp->n = atoi(cp);
		if((mp->seed = strtok(NULL," \t")) == NULL)
			continue;
		if((mp->val = strtok(NULL," \t")) == NULL)
			continue;
		if(strlen(mp->logname) == len
		 && strncmp(mp->logname,name,len) == 0){
			found = 1;
			break;
		}
	}
	if(found){
		fseek(mp->keyfile,recstart,0);
		return 0;
	} else
		return 1;
}
/* Verify response to a s/key challenge.
 *
 * Return codes:
 * -1: Error of some sort; database unchanged
 *  0:  Verify successful, database updated
 *  1:  Verify failed, database unchanged
 *
 * The database file is always closed by this call.
 */
int
skeyverify(mp,response)
struct skey *mp;
char *response;
{
 struct timeval startval;
 struct timeval endval;
long microsec;
	char key[8];
	char fkey[8];
	char filekey[8];
	time_t now;
	struct tm *tm;
	char tbuf[27],buf[60];
	char me[80];
	int rval;
	char *cp;

	time(&now);
	tm = localtime(&now);
	strftime(tbuf, sizeof(tbuf), " %b %d,%Y %T", tm);

	if(response == NULL){
		fclose(mp->keyfile);
		return -1;
	}
	rip(response);

	/* Convert response to binary */
	if(etob(key,response) != 1 && atob8(key,response) != 0){
		/* Neither english words or ascii hex */
		fclose(mp->keyfile);
		return -1;
	}

	/* Compute fkey = f(key) */
	memcpy(fkey,key,sizeof(key));
	f(fkey);
	/* in order to make the window of update as short as possible
           we must do the comparison here and if OK write it back
           other wise the same password can be used twice to get in
  	   to the system
	*/

	setpriority(PRIO_PROCESS, 0, -4);
/*
  gettimeofday(&startval, (char *)0 );
*/

	/* reread the file record NOW*/

	fseek(mp->keyfile,mp->recstart,0);
	if(fgets(mp->buf,sizeof(mp->buf),mp->keyfile) != mp->buf){
		setpriority(PRIO_PROCESS, 0, 0);
		fclose(mp->keyfile);
		return -1;
	}
	rip(mp->buf);
	mp->logname = strtok(mp->buf," \t");
	cp = strtok(NULL," \t") ;
	mp->seed = strtok(NULL," \t");
	mp->val = strtok(NULL," \t");
	/* And convert file value to hex for comparison */
	atob8(filekey,mp->val);

	/* Do actual comparison */
	if(memcmp(filekey,fkey,8) != 0){
		/* Wrong response */
		setpriority(PRIO_PROCESS, 0, 0);
		fclose(mp->keyfile);
		return 1;
	}

	/* Update key in database by overwriting entire record. Note
	 * that we must write exactly the same number of bytes as in
	 * the original record (note fixed width field for N)
	 */
	btoa8(mp->val,key);
	mp->n--;
	fseek(mp->keyfile,mp->recstart,0);
	fprintf(mp->keyfile,"%s %04d %-16s %s %-21s\n",mp->logname,mp->n,mp->seed,
	 mp->val, tbuf);
/*
gettimeofday(&endval, (char *)0 );
 microsec = (endval.tv_sec - startval.tv_sec) * 1000000 + (endval.tv_usec - startval.tv_usec);
fprintf(stderr, "window= %d micro seconds \n"  , microsec);
*/


	fclose(mp->keyfile);
	
	setpriority(PRIO_PROCESS, 0, 0);
	return 0;
}


/* Convert 8-byte hex-ascii string to binary array
 * Returns 0 on success, -1 on error
 */
atob8(out,in)
register char *out,*in;
{
	register int i;
	register int val;

	if(in == NULL || out == NULL)
		return -1;

	for(i=0;i<8;i++){
		if((in = skipspace(in)) == NULL)
			return -1;
		if((val = htoi(*in++)) == -1)
			return -1;
		*out = val << 4;

		if((in = skipspace(in)) == NULL)
			return -1;
		if((val = htoi(*in++)) == -1)
			return -1;
		*out++ |= val;
	}
	return 0;
}

char *
skipspace(cp)
register char *cp;
{
	while(*cp == ' ' || *cp == '\t')
		cp++;

	if(*cp == '\0')
		return NULL;
	else
		return cp;
}

/* Convert 8-byte binary array to hex-ascii string */
int
btoa8(out,in)
register char *out,*in;
{
	register int i;

	if(in == NULL || out == NULL)
		return -1;

	for(i=0;i<8;i++){
		sprintf(out,"%02x",*in++ & 0xff);
		out += 2;
	}
	return 0;
}


/* Convert hex digit to binary integer */
int
htoi(c)
register char c;
{
	if('0' <= c && c <= '9')
		return c - '0';
	if('a' <= c && c <= 'f')
		return 10 + c - 'a';
	if('A' <= c && c <= 'F')
		return 10 + c - 'A';
	return -1;
}