- (bal) Fixed uidswap.c so it should work on non-posix complient systems.

   patch based on 2.5.2 version by djm.

2 files changed, 45 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index d5834d55..76ad58a8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+20010427
+ - (bal) Fixed uidswap.c so it should work on non-posix complient systems.
+   patch based on 2.5.2 version by djm.
+
 20010425
  - OpenBSD CVS Sync
    - markus@cvs.openbsd.org 2001/04/23 21:57:07
@@ -5252,4 +5256,4 @@
  - Wrote replacements for strlcpy and mkdtemp
  - Released 1.0pre1
 
-$Id: ChangeLog,v 1.1171 2001/04/26 04:40:28 tim Exp $
+$Id: ChangeLog,v 1.1172 2001/04/26 23:03:37 mouring Exp $
diff --git a/uidswap.c b/uidswap.c
index 39952e2b..2c43877d 100644
--- a/uidswap.c
+++ b/uidswap.c
@@ -26,14 +26,18 @@ RCSID("$OpenBSD: uidswap.c,v 1.16 2001/04/20 16:32:22 markus Exp $");
  * POSIX saved uids or not.
  */
 
+#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
 /* Lets assume that posix saved ids also work with seteuid, even though that
    is not part of the posix specification. */
+#define SAVED_IDS_WORK_WITH_SETEUID
+/* Saved effective uid. */
+static uid_t 	saved_euid = 0;
+static gid_t	saved_egid = 0;
+#endif
 
 /* Saved effective uid. */
 static int	privileged = 0;
 static int	temporarily_use_uid_effective = 0;
-static uid_t	saved_euid = 0;
-static gid_t	saved_egid;
 static gid_t	saved_egroups[NGROUPS_MAX], user_groups[NGROUPS_MAX];
 static int	saved_egroupslen = -1, user_groupslen = -1;
 
@@ -45,16 +49,24 @@ void
 temporarily_use_uid(struct passwd *pw)
 {
 	/* Save the current euid, and egroups. */
+#ifdef SAVED_IDS_WORK_WITH_SETEUID
 	saved_euid = geteuid();
+	saved_egid = getegid();
 	debug("temporarily_use_uid: %d/%d (e=%d)",
 	    pw->pw_uid, pw->pw_gid, saved_euid);
 	if (saved_euid != 0) {
 		privileged = 0;
 		return;
 	}
+#else
+	if (geteuid() != 0) {
+		privileged = 0;
+		return;
+	}
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
+
 	privileged = 1;
 	temporarily_use_uid_effective = 1;
-	saved_egid = getegid();                                                       
 	saved_egroupslen = getgroups(NGROUPS_MAX, saved_egroups);                           
 	if (saved_egroupslen < 0)
 		fatal("getgroups: %.100s", strerror(errno));
@@ -71,7 +83,14 @@ temporarily_use_uid(struct passwd *pw)
 	/* Set the effective uid to the given (unprivileged) uid. */
 	if (setgroups(user_groupslen, user_groups) < 0)
 		fatal("setgroups: %.100s", strerror(errno));
-	pw->pw_gid = pw->pw_gid;
+#ifndef SAVED_IDS_WORK_WITH_SETEUID
+	/* Propagate the privileged gid to all of our gids. */
+	if (setgid(getegid()) < 0)
+		debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
+	/* Propagate the privileged uid to all of our uids. */
+	if (setuid(geteuid()) < 0)
+		debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
 	if (setegid(pw->pw_gid) < 0)
 		fatal("setegid %u: %.100s", (u_int) pw->pw_gid,
 		    strerror(errno));
@@ -92,13 +111,27 @@ restore_uid(void)
 		return;
 	if (!temporarily_use_uid_effective)
 		fatal("restore_uid: temporarily_use_uid not effective");
+
+#ifdef SAVED_IDS_WORK_WITH_SETEUID
 	/* Set the effective uid back to the saved privileged uid. */
 	if (seteuid(saved_euid) < 0)
-		fatal("seteuid %u: %.100s", (u_int) saved_euid, strerror(errno));
+		fatal("seteuid %u: %.100s", (u_int) saved_euid, 
+		    strerror(errno));
+	if (setegid(saved_egid) < 0)
+		fatal("setegid %u: %.100s", (u_int) saved_egid, 
+		    strerror(errno));
+#else /* SAVED_IDS_WORK_WITH_SETEUID */
+	/*
+	 * We are unable to restore the real uid to its unprivileged value.
+	 * Propagate the real uid (usually more privileged) to effective uid
+	 * as well.
+	 */
+	setuid(getuid());
+	setgid(getgid());
+#endif /* SAVED_IDS_WORK_WITH_SETEUID */
+
 	if (setgroups(saved_egroupslen, saved_egroups) < 0)
 		fatal("setgroups: %.100s", strerror(errno));
-	if (setegid(saved_egid) < 0)
-		fatal("setegid %u: %.100s", (u_int) saved_egid, strerror(errno));
 	temporarily_use_uid_effective = 0;
 }