dist/ntp/libntp/authreadkeys.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * authreadkeys.c - routines to support the reading of the key file
   5  */
   6 #include <stdio.h>
   7 #include <ctype.h>
   8
   9 #include "ntp_fp.h"
  10 #include "ntp.h"
  11 #include "ntp_syslog.h"
  12 #include "ntp_stdlib.h"
  13
  14 /*
  15  *  Arbitrary long string of ASCII characters.
  16  */
  17 #define KEY_TYPE_MD5    4
  18
  19 /* Forwards */
  20 static char *nexttok P((char **));
  21
  22 /*
  23  * nexttok - basic internal tokenizing routine
  24  */
  25 static char *
  26 nexttok(
  27         char **str
  28         )
  29 {
  30         register char *cp;
  31         char *starttok;
  32
  33         cp = *str;
  34
  35         /*
  36          * Space past white space
  37          */
  38         while (*cp == ' ' || *cp == '\t')
  39             cp++;
  40
  41         /*
  42          * Save this and space to end of token
  43          */
  44         starttok = cp;
  45         while (*cp != '\0' && *cp != '\n' && *cp != ' '
  46                && *cp != '\t' && *cp != '#')
  47             cp++;
  48
  49         /*
  50          * If token length is zero return an error, else set end of
  51          * token to zero and return start.
  52          */
  53         if (starttok == cp)
  54             return 0;
  55
  56         if (*cp == ' ' || *cp == '\t')
  57             *cp++ = '\0';
  58         else
  59             *cp = '\0';
  60
  61         *str = cp;
  62         return starttok;
  63 }
  64
  65
  66 /*
  67  * authreadkeys - (re)read keys from a file.
  68  */
  69 int
  70 authreadkeys(
  71         const char *file
  72         )
  73 {
  74         FILE *fp;
  75         char *line;
  76         char *token;
  77         u_long keyno;
  78         int keytype;
  79         char buf[512];          /* lots of room for line */
  80
  81         /*
  82          * Open file.  Complain and return if it can't be opened.
  83          */
  84         fp = fopen(file, "r");
  85         if (fp == NULL) {
  86                 msyslog(LOG_ERR, "can't open key file %s: %m", file);
  87                 return 0;
  88         }
  89
  90         /*
  91          * Remove all existing keys
  92          */
  93         auth_delkeys();
  94
  95         /*
  96          * Now read lines from the file, looking for key entries
  97          */
  98         while ((line = fgets(buf, sizeof buf, fp)) != NULL) {
  99                 token = nexttok(&line);
 100                 if (token == 0)
 101                     continue;
 102
 103                 /*
 104                  * First is key number.  See if it is okay.
 105                  */
 106                 keyno = atoi(token);
 107                 if (keyno == 0) {
 108                         msyslog(LOG_ERR,
 109                                 "cannot change keyid 0, key entry `%s' ignored",
 110                                 token);
 111                         continue;
 112                 }
 113
 114                 if (keyno > NTP_MAXKEY) {
 115                         msyslog(LOG_ERR,
 116                                 "keyid's > %d reserved for autokey, key entry `%s' ignored",
 117                                 NTP_MAXKEY, token);
 118                         continue;
 119                 }
 120
 121                 /*
 122                  * Next is keytype.  See if that is all right.
 123                  */
 124                 token = nexttok(&line);
 125                 if (token == 0) {
 126                         msyslog(LOG_ERR,
 127                                 "no key type for key number %ld, entry ignored",
 128                                 keyno);
 129                         continue;
 130                 }
 131                 switch (*token) {
 132                     case 'M':
 133                     case 'm':
 134                         keytype = KEY_TYPE_MD5; break;
 135                     default:
 136                         msyslog(LOG_ERR,
 137                                 "invalid key type for key number %ld, entry ignored",
 138                                 keyno);
 139                         continue;
 140                 }
 141
 142                 /*
 143                  * Finally, get key and insert it
 144                  */
 145                 token = nexttok(&line);
 146                 if (token == 0) {
 147                         msyslog(LOG_ERR,
 148                                 "no key for number %ld entry, entry ignored",
 149                                 keyno);
 150                 } else {
 151                         switch(keytype) {
 152                             case KEY_TYPE_MD5:
 153                                 if (!authusekey(keyno, keytype,
 154                                                 (u_char *)token))
 155                                     msyslog(LOG_ERR,
 156                                             "format/parity error for MD5 key %ld, not used",
 157                                             keyno);
 158                                 break;
 159                         }
 160                 }
 161         }
 162         (void) fclose(fp);
 163         return 1;
 164 }