Drop root priviledges

[Yuri Polyansky]

             HI!

  Just  in  case you're  interested.  Here is  a  patch  to drop  root
  priviliges.

  Useful for security parnoids  who don't believe your code unblowable
  ;-).

  Thanks!

                              Cheers,
                                        -up

diff -ur httptunnel-3.3/common.h httptunnel-3.3.secure/common.h
--- httptunnel-3.3/common.h     Tue Jul 25 13:01:35 2000
+++ httptunnel-3.3.secure/common.h      Sun Oct 20 23:50:36 2002
@@ -28,6 +28,7 @@
 #define DEFAULT_KEEP_ALIVE 5 /* seconds */
 #define DEFAULT_MAX_CONNECTION_AGE 300 /* seconds */
 #define BUG_REPORT_EMAIL "bug-httptunnel@gnu.org"
+#define DEFAULT_UID 100

 #ifndef TRUE
 #define TRUE 1
diff -ur httptunnel-3.3/hts.c httptunnel-3.3.secure/hts.c
--- httptunnel-3.3/hts.c        Sun Feb 25 14:56:37 2001
+++ httptunnel-3.3.secure/hts.c Mon Oct 21 00:41:15 2002
@@ -26,6 +26,7 @@
   int forward_port;
   size_t content_length;
   char *pid_filename;
+  int uid;
   int use_std;
   int use_daemon;
   int strict_content_length;
@@ -63,6 +64,7 @@
 "                                 open is SEC seconds (default is %d)\n"
 "  -s, --stdin-stdout             use stdin/stdout for communication\n"
 "                                 (implies --no-daemon)\n"
+"  -U, --uid                     setuid() to this uid\n"
 "  -S, --strict-content-length    always write Content-Length bytes in 
requests\n"
 "  -V, --version                  output version information and exit\n"
 "  -w, --no-daemon                don't fork into the background\n"
@@ -93,6 +95,7 @@
   arg->strict_content_length = FALSE;
   arg->keep_alive = DEFAULT_KEEP_ALIVE;
   arg->max_connection_age = DEFAULT_CONNECTION_MAX_TIME;
+  arg->uid = -1;

   for (;;)
     {
@@ -114,10 +117,11 @@
        { "forward-port", required_argument, 0, 'F' },
        { "content-length", required_argument, 0, 'c' },
        { "max-connection-age", required_argument, 0, 'M' },
+       { "uid", required_argument, 0, 'U' },
        { 0, 0, 0, 0 }
       };

-      static const char *short_options = "c:d:F:hk:M:p:sSVw"
+      static const char *short_options = "c:d:F:hk:M:p:sSVwU:"
 #ifdef DEBUG_MODE
        "D:l:"
 #endif
@@ -203,6 +207,10 @@
        case 'p':
          arg->pid_filename = optarg;
          break;
+
+       case 'U':
+         arg->uid = atoi(optarg);
+         break;

        case 'w':
          arg->use_daemon = FALSE;
@@ -307,14 +315,28 @@
   log_notice ("  debug_level = %d", debug_level);
   log_notice ("  pid_filename = %s",
              arg.pid_filename ? arg.pid_filename : "(null)");
+  log_notice ("  uid = %d", arg.uid);

   tunnel = tunnel_new_server (arg.host, arg.port, arg.content_length);
+
   if (tunnel == NULL)
     {
       log_error ("couldn't create tunnel", argv[0]);
       log_exit (1);
     }

+  /* Dropping privileges */
+  if((getuid() == 0) || (arg.uid != -1)){
+         int uid = (arg.uid != -1) ? arg.uid : DEFAULT_UID;
+         log_notice("called with uid = %d, dropping to %d...", getuid(), uid);
+         if(setuid(uid)){
+                 /* avoiding CAP_* hack */
+                 log_error("setuid(%d) failed while running with uid = %d\n", 
uid, getuid());
+                 log_exit(1);
+         }
+  }
+  log_notice("setuid() succeeded, getuid() = %d\n", getuid());
+
   if (tunnel_setopt (tunnel, "strict_content_length",
                     &arg.strict_content_length) == -1)
     log_debug ("tunnel_setopt strict_content_length error: %s",