- markus@cvs.openbsd.org 2002/03/21 21:23:34

     [sshd.c]
     add privsep_preauth() and remove 1 goto; ok provos@

diff --git a/ChangeLog b/ChangeLog
index 961e24501adc0e9adda900f975e85a95a88e9561..c54aa80e0bb4c0b2cb823156fb1fa36ccdc224c4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -133,6 +133,9 @@
    - markus@cvs.openbsd.org 2002/03/21 20:51:12
      [sshd_config]
      add privsep (off)
+   - markus@cvs.openbsd.org 2002/03/21 21:23:34
+     [sshd.c]
+     add privsep_preauth() and remove 1 goto; ok provos@
 
 20020317
  - (tim) [configure.ac] Assume path given with --with-pid-dir=PATH is wanted,

diff --git a/sshd.c b/sshd.c
index 26124b77736a16464036a839b03f12f2ffed00ab..c80dfc1466aed82bc36caf6b929c97afc6fede42 100644 (file)
--- a/sshd.c
+++ b/sshd.c
@@ -42,7 +42,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.236 2002/03/20 21:08:08 stevesk Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.237 2002/03/21 21:23:34 markus Exp $");
 
 #include <openssl/dh.h>
 #include <openssl/bn.h>
@@ -551,14 +551,51 @@ privsep_preauth_child(void)
        do_setusercontext(pw);
 }
 
-static void
-privsep_postauth(Authctxt *authctxt, pid_t pid)
+static Authctxt*
+privsep_preauth(void)
 {
-       extern Authctxt *x_authctxt;
+       Authctxt *authctxt = NULL;
        int status;
+       pid_t pid;
 
-       /* Wait for the child's exit status */
-       waitpid(pid, &status, 0);
+       /* Set up unprivileged child process to deal with network data */
+       monitor = monitor_init();
+       /* Store a pointer to the kex for later rekeying */
+       monitor->m_pkex = &xxx_kex;
+
+       pid = fork();
+       if (pid == -1) {
+               fatal("fork of unprivileged child failed");
+       } else if (pid != 0) {
+               debug2("Network child is on pid %d", pid);
+
+               close(monitor->m_recvfd);
+               authctxt = monitor_child_preauth(monitor);
+               close(monitor->m_sendfd);
+
+               /* Sync memory */
+               monitor_sync(monitor);
+
+               /* Wait for the child's exit status */
+               waitpid(pid, &status, 0);
+
+               return (authctxt);
+       } else {
+               /* child */
+
+               close(monitor->m_sendfd);
+
+               /* Demote the child */
+               if (getuid() == 0 || geteuid() == 0)
+                       privsep_preauth_child();
+       }
+       return (NULL);
+}
+
+static void
+privsep_postauth(Authctxt *authctxt)
+{
+       extern Authctxt *x_authctxt;
 
        /* XXX - Remote port forwarding */
        x_authctxt = authctxt;
@@ -584,7 +621,7 @@ privsep_postauth(Authctxt *authctxt, pid_t pid)
        if (monitor->m_pid == -1)
                fatal("fork of unprivileged child failed");
        else if (monitor->m_pid != 0) {
-               debug2("User child is on pid %d", pid);
+               debug2("User child is on pid %d", monitor->m_pid);
                close(monitor->m_recvfd);
                monitor_child_postauth(monitor);
 
@@ -604,7 +641,6 @@ privsep_postauth(Authctxt *authctxt, pid_t pid)
        monitor_apply_keystate(monitor);
 }
 
-
 static char *
 list_hostkey_types(void)
 {
@@ -1379,36 +1415,9 @@ main(int ac, char **av)
 
        packet_set_nonblocking();
 
-       if (!use_privsep)
-               goto skip_privilegeseparation;
-
-       /* Set up unprivileged child process to deal with network data */
-       monitor = monitor_init();
-       /* Store a pointer to the kex for later rekeying */
-       monitor->m_pkex = &xxx_kex;
-
-       pid = fork();
-       if (pid == -1)
-               fatal("fork of unprivileged child failed");
-       else if (pid != 0) {
-               debug2("Network child is on pid %d", pid);
-
-               close(monitor->m_recvfd);
-               authctxt = monitor_child_preauth(monitor);
-               close(monitor->m_sendfd);
-
-               /* Sync memory */
-               monitor_sync(monitor);
-               goto authenticated;
-       } else {
-               close(monitor->m_sendfd);
-
-               /* Demote the child */
-               if (getuid() == 0 || geteuid() == 0)
-                       privsep_preauth_child();
-       }
-
- skip_privilegeseparation:
+       if (use_privsep)
+               if ((authctxt = privsep_preauth()) != NULL)
+                       goto authenticated;
 
        /* perform the key exchange */
        /* authenticate user and start session */
@@ -1419,12 +1428,14 @@ main(int ac, char **av)
                do_ssh1_kex();
                authctxt = do_authentication();
        }
-       if (use_privsep)
+       /*
+        * If we use privilege separation, the unprivileged child transfers
+        * the current keystate and exits
+        */
+       if (use_privsep) {
                mm_send_keystate(monitor);
-
-       /* If we use privilege separation, the unprivileged child exits */
-       if (use_privsep)
                exit(0);
+       }
 
  authenticated:
        /*
@@ -1432,7 +1443,8 @@ main(int ac, char **av)
         * file descriptor passing.
         */
        if (use_privsep) {
-               privsep_postauth(authctxt, pid);
+               privsep_postauth(authctxt);
+               /* the monitor process [priv] will not return */
                if (!compat20)
                        destroy_sensitive_data();
        }