345 lines
7.2 KiB
C
345 lines
7.2 KiB
C
/* 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>
|
|
#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"
|
|
#include "pathnames.h"
|
|
|
|
char *skipspace();
|
|
int skeylookup __P((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, *p;
|
|
struct stat statbuf;
|
|
|
|
/* See if the _PATH_SKEYFILE exists, and create it if not */
|
|
if(stat(_PATH_SKEYFILE,&statbuf) == -1 && errno == ENOENT){
|
|
mp->keyfile = fopen(_PATH_SKEYFILE,"w+");
|
|
(void) chmod(_PATH_SKEYFILE, 0644);
|
|
} else {
|
|
/* Otherwise open normally for update */
|
|
mp->keyfile = fopen(_PATH_SKEYFILE,"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 */
|
|
p = mp->buf;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
if((mp->logname = cp) == NULL)
|
|
continue;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
if(cp == NULL)
|
|
continue;
|
|
mp->n = atoi(cp);
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
if((mp->seed = cp) == NULL)
|
|
continue;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
if((mp->val = cp) == 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, *p;
|
|
|
|
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);
|
|
p = mp->buf;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
mp->logname = cp;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
mp->seed = cp;
|
|
while ((cp = strsep(&p, " \t")) != NULL && *cp == '\0')
|
|
;
|
|
mp->val = cp;
|
|
/* 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;
|
|
}
|