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/*
* authreadkeys.c - routines to support the reading of the key file
*/
#include <stdio.h>
#include <ctype.h>
#include "ntp_fp.h"
#include "ntp.h"
#include "ntp_stdlib.h"
#include "ntp_syslog.h"
#ifdef DES
/*
* Types of ascii representations for keys. "Standard" means a 64 bit
* hex number in NBS format, i.e. with the low order bit of each byte
* a parity bit. "NTP" means a 64 bit key in NTP format, with the
* high order bit of each byte a parity bit. "Ascii" means a 1-to-8
* character string whose ascii representation is used as the key.
*/
#define KEY_TYPE_STD 1
#define KEY_TYPE_NTP 2
#define KEY_TYPE_ASCII 3
#endif
#ifdef MD5
/*
* Arbitrary long string of ASCII characters.
*/
#define KEY_TYPE_MD5 4
#endif
/* Forwards */
static char *nexttok P((char **));
/*
* nexttok - basic internal tokenizing routine
*/
static char *
nexttok(
char **str
)
{
register char *cp;
char *starttok;
cp = *str;
/*
* Space past white space
*/
while (*cp == ' ' || *cp == '\t')
cp++;
/*
* Save this and space to end of token
*/
starttok = cp;
while (*cp != '\0' && *cp != '\n' && *cp != ' '
&& *cp != '\t' && *cp != '#')
cp++;
/*
* If token length is zero return an error, else set end of
* token to zero and return start.
*/
if (starttok == cp)
return 0;
if (*cp == ' ' || *cp == '\t')
*cp++ = '\0';
else
*cp = '\0';
*str = cp;
return starttok;
}
/*
* authreadkeys - (re)read keys from a file.
*/
int
authreadkeys(
const char *file
)
{
FILE *fp;
char *line;
char *token;
u_long keyno;
int keytype;
char buf[512]; /* lots of room for line */
/*
* Open file. Complain and return if it can't be opened.
*/
fp = fopen(file, "r");
if (fp == NULL) {
msyslog(LOG_ERR, "can't open key file %s: %m", file);
return 0;
}
/*
* Remove all existing keys
*/
auth_delkeys();
/*
* Now read lines from the file, looking for key entries
*/
while ((line = fgets(buf, sizeof buf, fp)) != NULL) {
token = nexttok(&line);
if (token == 0)
continue;
/*
* First is key number. See if it is okay.
*/
keyno = atoi(token);
if (keyno == 0) {
msyslog(LOG_ERR,
"cannot change keyid 0, key entry `%s' ignored",
token);
continue;
}
if (keyno > NTP_MAXKEY) {
msyslog(LOG_ERR,
"keyid's > %d reserved for autokey, key entry `%s' ignored",
NTP_MAXKEY, token);
continue;
}
/*
* Next is keytype. See if that is all right.
*/
token = nexttok(&line);
if (token == 0) {
msyslog(LOG_ERR,
"no key type for key number %ld, entry ignored",
keyno);
continue;
}
switch (*token) {
#ifdef DES
case 'S':
case 's':
keytype = KEY_TYPE_STD; break;
case 'N':
case 'n':
keytype = KEY_TYPE_NTP; break;
case 'A':
case 'a':
keytype = KEY_TYPE_ASCII; break;
#endif
#ifdef MD5
case 'M':
case 'm':
keytype = KEY_TYPE_MD5; break;
#endif
default:
msyslog(LOG_ERR,
"invalid key type for key number %ld, entry ignored",
keyno);
continue;
}
/*
* Finally, get key and insert it
*/
token = nexttok(&line);
if (token == 0) {
msyslog(LOG_ERR,
"no key for number %ld entry, entry ignored",
keyno);
} else {
switch(keytype) {
#ifdef DES
case KEY_TYPE_STD:
case KEY_TYPE_NTP:
case KEY_TYPE_ASCII:
if (!authusekey(keyno, keytype,
(u_char *)token))
msyslog(LOG_ERR,
"format/parity error for DES key %ld, not used",
keyno);
break;
#endif
#ifdef MD5
case KEY_TYPE_MD5:
if (!authusekey(keyno, keytype,
(u_char *)token))
msyslog(LOG_ERR,
"format/parity error for MD5 key %ld, not used",
keyno);
break;
#endif
}
}
}
(void) fclose(fp);
return 1;
}
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