/contrib/ntp/libntp/authreadkeys.c

  1/*
  2 * authreadkeys.c - routines to support the reading of the key file
  3 */
  4#include <stdio.h>
  5#include <ctype.h>
  6
  7#include "ntp_fp.h"
  8#include "ntp.h"
  9#include "ntp_syslog.h"
 10#include "ntp_stdlib.h"
 11
 12/*
 13 *  Arbitrary long string of ASCII characters.
 14 */
 15#define	KEY_TYPE_MD5	4
 16
 17/* Forwards */
 18static char *nexttok P((char **));
 19
 20/*
 21 * nexttok - basic internal tokenizing routine
 22 */
 23static char *
 24nexttok(
 25	char **str
 26	)
 27{
 28	register char *cp;
 29	char *starttok;
 30
 31	cp = *str;
 32
 33	/*
 34	 * Space past white space
 35	 */
 36	while (*cp == ' ' || *cp == '\t')
 37	    cp++;
 38	
 39	/*
 40	 * Save this and space to end of token
 41	 */
 42	starttok = cp;
 43	while (*cp != '\0' && *cp != '\n' && *cp != ' '
 44	       && *cp != '\t' && *cp != '#')
 45	    cp++;
 46	
 47	/*
 48	 * If token length is zero return an error, else set end of
 49	 * token to zero and return start.
 50	 */
 51	if (starttok == cp)
 52	    return 0;
 53	
 54	if (*cp == ' ' || *cp == '\t')
 55	    *cp++ = '\0';
 56	else
 57	    *cp = '\0';
 58	
 59	*str = cp;
 60	return starttok;
 61}
 62
 63
 64/*
 65 * authreadkeys - (re)read keys from a file.
 66 */
 67int
 68authreadkeys(
 69	const char *file
 70	)
 71{
 72	FILE *fp;
 73	char *line;
 74	char *token;
 75	u_long keyno;
 76	int keytype;
 77	char buf[512];		/* lots of room for line */
 78
 79	/*
 80	 * Open file.  Complain and return if it can't be opened.
 81	 */
 82	fp = fopen(file, "r");
 83	if (fp == NULL) {
 84		msyslog(LOG_ERR, "can't open key file %s: %m", file);
 85		return 0;
 86	}
 87
 88	/*
 89	 * Remove all existing keys
 90	 */
 91	auth_delkeys();
 92
 93	/*
 94	 * Now read lines from the file, looking for key entries
 95	 */
 96	while ((line = fgets(buf, sizeof buf, fp)) != NULL) {
 97		token = nexttok(&line);
 98		if (token == 0)
 99		    continue;
100		
101		/*
102		 * First is key number.  See if it is okay.
103		 */
104		keyno = atoi(token);
105		if (keyno == 0) {
106			msyslog(LOG_ERR,
107				"cannot change keyid 0, key entry `%s' ignored",
108				token);
109			continue;
110		}
111
112		if (keyno > NTP_MAXKEY) {
113			msyslog(LOG_ERR,
114				"keyid's > %d reserved for autokey, key entry `%s' ignored",
115				NTP_MAXKEY, token);
116			continue;
117		}
118
119		/*
120		 * Next is keytype.  See if that is all right.
121		 */
122		token = nexttok(&line);
123		if (token == 0) {
124			msyslog(LOG_ERR,
125				"no key type for key number %ld, entry ignored",
126				keyno);
127			continue;
128		}
129		switch (*token) {
130		    case 'M':
131		    case 'm':
132			keytype = KEY_TYPE_MD5; break;
133		    default:
134			msyslog(LOG_ERR,
135				"invalid key type for key number %ld, entry ignored",
136				keyno);
137			continue;
138		}
139
140		/*
141		 * Finally, get key and insert it
142		 */
143		token = nexttok(&line);
144		if (token == 0) {
145			msyslog(LOG_ERR,
146				"no key for number %ld entry, entry ignored",
147				keyno);
148		} else {
149			switch(keytype) {
150			    case KEY_TYPE_MD5:
151				if (!authusekey(keyno, keytype,
152						(u_char *)token))
153				    msyslog(LOG_ERR,
154					    "format/parity error for MD5 key %ld, not used",
155					    keyno);
156				break;
157			}
158		}
159	}
160	(void) fclose(fp);
161	return 1;
162}