contrib/opie/libopie/insecure.c

   1 /* insecure.c: The opieinsecure() library function.
   2
   3 %%% portions-copyright-cmetz-96
   4 Portions of this software are Copyright 1996-1999 by Craig Metz, All Rights
   5 Reserved. The Inner Net License Version 2 applies to these portions of
   6 the software.
   7 You should have received a copy of the license with this software. If
   8 you didn't get a copy, you may request one from <license@inner.net>.
   9
  10 Portions of this software are Copyright 1995 by Randall Atkinson and Dan
  11 McDonald, All Rights Reserved. All Rights under this copyright are assigned
  12 to the U.S. Naval Research Laboratory (NRL). The NRL Copyright Notice and
  13 License Agreement applies to this software.
  14
  15         History:
  16
  17         Modified by cmetz for OPIE 2.4. Do utmp checks on utmpx systems.
  18              Handle unterminated ut_host.
  19         Modified by cmetz for OPIE 2.31. Fixed a logic bug. Call endut[x]ent().
  20         Modified by cmetz for OPIE 2.3. Added result caching. Use
  21              __opiegetutmpentry(). Ifdef around ut_host check. Eliminate
  22              unused variable.
  23         Modified by cmetz for OPIE 2.2. Use FUNCTION declaration et al.
  24              Allow IP loopback. DISPLAY and ut_host must match exactly,
  25              not just the part before the colon. Added work-around for
  26              Sun CDE dtterm bug. Leave the environment as it was
  27              found. Use uname().
  28         Created at NRL for OPIE 2.2 from opiesubr.c. Fixed pointer
  29              assignment that should have been a comparison.
  30
  31 $FreeBSD: src/contrib/opie/libopie/insecure.c,v 1.1.1.2.6.2 2002/07/15 14:48:47 des Exp $
  32 $DragonFly: src/contrib/opie/libopie/insecure.c,v 1.2 2003/06/17 04:24:05 dillon Exp $
  33
  34 */
  35 #include "opie_cfg.h"
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <stdlib.h>     /* ANSI C standard library */
  40 #include <sys/param.h>
  41 #include <unistd.h>
  42
  43 #include <utmp.h>
  44 #if DOUTMPX
  45 #include <utmpx.h>
  46 #define utmp utmpx
  47 #define endutent endutxent
  48 #endif  /* DOUTMPX */
  49
  50 #if HAVE_SYS_UTSNAME_H
  51 #include <sys/utsname.h>
  52 #endif /* HAVE_SYS_UTSNAME_H */
  53
  54 #include "opie.h"
  55
  56 char *remote_terms[] = { "xterm", "xterms", "kterm", NULL };
  57
  58 int opieinsecure FUNCTION_NOARGS
  59 {
  60 #ifndef NO_INSECURE_CHECK
  61   char *display_name;
  62   char *s;
  63   char *term_name;
  64   int  insecure = 0;
  65 #if HAVE_UT_HOST || DOUTMPX
  66   struct utmp utmp;
  67 #endif /* HAVE_UT_HOST || DOUTMPX */
  68   static int result = -1;
  69
  70   if (result != -1)
  71     return result;
  72
  73   if (getenv("SSH_CLIENT") != NULL)
  74         return (result = 0);
  75   display_name = (char *) getenv("DISPLAY");
  76   term_name = (char *) getenv("TERM");
  77
  78   if (display_name) {
  79     insecure = 1;
  80     if (s = strchr(display_name, ':')) {
  81       int n = s - display_name;
  82       if (!n)
  83         insecure = 0;
  84       else {
  85         if (!strncmp("unix", display_name, n))
  86           insecure = 0;
  87         else if (!strncmp("localhost", display_name, n))
  88             insecure = 0;
  89         else if (!strncmp("loopback", display_name, n))
  90             insecure = 0;
  91         else if (!strncmp("127.0.0.1", display_name, n))
  92             insecure = 0;
  93         else {
  94           struct utsname utsname;
  95
  96           if (!uname(&utsname)) {
  97             if (!strncmp(utsname.nodename, display_name, n))
  98               insecure = 0;
  99             else {
 100               if (s = strchr(display_name, '.')) {
 101                 int n2 = s - display_name;
 102                 if (n < n2)
 103                   n2 = n;
 104                 if (!strncmp(utsname.nodename, display_name, n2))
 105                   insecure = 0;
 106               } /* endif display_name is '.' */
 107             } /* endif hostname != display_name */
 108           } /* endif was able to get hostname */
 109         } /* endif display_name == UNIX */
 110       }
 111     }
 112     } /* endif display_name == ":" */
 113     if (insecure)
 114       return (result = 1);
 115
 116   /* If no DISPLAY variable exists and TERM=xterm,
 117      then we probably have an xterm executing on a remote system
 118      with an rlogin or telnet to our system.  If it were a local
 119      xterm, then the DISPLAY environment variable would
 120      have to exist. rja */
 121   if (!display_name && term_name) {
 122     int i;
 123     for (i = 0; remote_terms[i]; i++)
 124       if (!strcmp(term_name, remote_terms[i]))
 125         return (result = 1);
 126   };
 127
 128 #if HAVE_UT_HOST || DOUTMPX
 129   if (isatty(0)) {
 130     memset(&utmp, 0, sizeof(struct utmp));
 131     {
 132       int i = __opiegetutmpentry(ttyname(0), &utmp);
 133       endutent();
 134       if (!i && utmp.ut_host[0]) {
 135         char host[sizeof(utmp.ut_host) + 1];
 136         insecure = 1;
 137
 138         strncpy(host, utmp.ut_host, sizeof(utmp.ut_host));
 139         host[sizeof(utmp.ut_host)] = 0;
 140
 141         if (s = strchr(host, ':')) {
 142           int n = s - host;
 143           if (!n)
 144             insecure = 0;
 145           else
 146             if (display_name) {
 147               if (!strncmp(host, display_name, n))
 148                 insecure = 0;
 149 #if 1 /* def SOLARIS */
 150               else
 151                 if (s = strchr(host, ' ')) {
 152                   *s = ':';
 153                   if (s = strchr(s + 1, ' '))
 154                     *s = '.';
 155                   if (!strncmp(host, display_name, n))
 156                     insecure = 0;
 157                 }
 158 #endif /* SOLARIS */
 159             }
 160         }
 161       }
 162     };
 163   };
 164 #endif /* HAVE_UT_HOST || DOUTMPX */
 165   if (insecure)
 166     return (result = 1);
 167
 168   return (result = 0);
 169 #else /* NO_INSECURE_CHECK */
 170   return 0;
 171 #endif /* NO_INSECURE_CHECK */
 172 }