6 files changed, 48 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index 7c30a33ac..0ce7f8c6b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,6 +42,9 @@
      [readpass.c sshconnect.c sshconnect.h sshconnect2.c uidswap.c]
      replace remaining setuid() calls with permanently_set_uid() and
      check seteuid() return values; report Marcus Meissner; ok dtucker djm
+   - markus@cvs.openbsd.org 2006/06/08 14:45:49
+     [readpass.c sshconnect.c sshconnect2.c uidswap.c uidswap.h]
+     do not set the gid, noted by solar; ok djm
 
 20060521
  - (dtucker) [auth.c monitor.c] Now that we don't log from both the monitor
@@ -4675,4 +4678,4 @@
    - (djm) Trim deprecated options from INSTALL. Mention UsePAM
    - (djm) Fix quote handling in sftp; Patch from admorten AT umich.edu
 
-$Id: ChangeLog,v 1.4341 2006/06/13 03:05:15 djm Exp $
+$Id: ChangeLog,v 1.4342 2006/06/13 03:10:00 djm Exp $
diff --git a/readpass.c b/readpass.c
index 60e4a902f..34d70b07a 100644
--- a/readpass.c
+++ b/readpass.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readpass.c,v 1.38 2006/06/06 10:20:20 markus Exp $ */
+/* $OpenBSD: readpass.c,v 1.39 2006/06/08 14:45:49 markus Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -61,7 +61,7 @@ ssh_askpass(char *askpass, const char *msg)
                 return NULL;
         }
         if (pid == 0) {
-                permanently_set_uid(getpwuid(getuid()));
+                permanently_drop_suid(getuid());
                 close(p[0]);
                 if (dup2(p[1], STDOUT_FILENO) < 0)
                         fatal("ssh_askpass: dup2: %s", strerror(errno));
diff --git a/sshconnect.c b/sshconnect.c
index 41ad82f9f..c76572662 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.183 2006/06/06 10:20:20 markus Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.184 2006/06/08 14:45:49 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -97,7 +97,7 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
                 char *argv[10];
 
                 /* Child.  Permanently give up superuser privileges. */
-                permanently_set_uid(getpwuid(original_real_uid));
+                permanently_drop_suid(original_real_uid);
 
                 /* Redirect stdin and stdout. */
                 close(pin[1]);
diff --git a/sshconnect2.c b/sshconnect2.c
index c97738c7b..4f96dcfc4 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.154 2006/06/06 10:20:20 markus Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.155 2006/06/08 14:45:49 markus Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -1253,7 +1253,7 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
                 return -1;
         }
         if (pid == 0) {
-                permanently_set_uid(getpwuid(getuid()));
+                permanently_drop_suid(getuid());
                 close(from[0]);
                 if (dup2(from[1], STDOUT_FILENO) < 0)
                         fatal("ssh_keysign: dup2: %s", strerror(errno));
diff --git a/uidswap.c b/uidswap.c
index ba2d20942..e5b0595ac 100644
--- a/uidswap.c
+++ b/uidswap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: uidswap.c,v 1.28 2006/06/06 10:20:20 markus Exp $ */
+/* $OpenBSD: uidswap.c,v 1.29 2006/06/08 14:45:49 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -123,6 +123,41 @@ temporarily_use_uid(struct passwd *pw)
                     strerror(errno));
 }
 
+void
+permanently_drop_suid(uid_t uid)
+{
+        uid_t old_uid = getuid();
+
+        debug("permanently_drop_suid: %u", (u_int)uid);
+#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
+        if (setresuid(uid, uid, uid) < 0)
+                fatal("setresuid %u: %.100s", (u_int)uid, strerror(errno));
+#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
+        if (setreuid(uid, uid) < 0)
+                fatal("setreuid %u: %.100s", (u_int)uid, strerror(errno));
+#else
+# ifndef SETEUID_BREAKS_SETUID
+        if (seteuid(uid) < 0)
+                fatal("seteuid %u: %.100s", (u_int)uid, strerror(errno));
+# endif
+        if (setuid(uid) < 0)
+                fatal("setuid %u: %.100s", (u_int)uid, strerror(errno));
+#endif
+
+#ifndef HAVE_CYGWIN
+        /* Try restoration of UID if changed (test clearing of saved uid) */
+        if (old_uid != uid &&
+            (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
+                fatal("%s: was able to restore old [e]uid", __func__);
+#endif
+
+        /* Verify UID drop was successful */
+        if (getuid() != uid || geteuid() != uid) {
+                fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
+                    __func__, (u_int)getuid(), (u_int)geteuid(), (u_int)uid);
+        }
+}
+
 /*
  * Restores to the original (privileged) uid.
  */
diff --git a/uidswap.h b/uidswap.h
index 967ea9c4d..f827782d5 100644
--- a/uidswap.h
+++ b/uidswap.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: uidswap.h,v 1.10 2006/03/25 22:22:43 djm Exp $ */
+/* $OpenBSD: uidswap.h,v 1.11 2006/06/08 14:45:49 markus Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -18,5 +18,6 @@
 void     temporarily_use_uid(struct passwd *);
 void     restore_uid(void);
 void     permanently_set_uid(struct passwd *);
+void     permanently_drop_suid(uid_t);
 
 #endif                          /* UIDSWAP_H */