Remove support for running ssh(1) setuid and fatal if attempted.

Do not link uidwap.c into ssh any more.  Neuters UsePrivilegedPort,
which will be marked as deprecated shortly. ok markus@ djm@

1 files changed, 7 insertions, 33 deletions

diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index aeaae37936a..7192be01772 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.486 2018/07/16 22:25:01 dtucker Exp $ */
+/* $OpenBSD: ssh.c,v 1.487 2018/07/18 11:34:04 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -94,7 +94,6 @@
 #include "sshpty.h"
 #include "match.h"
 #include "msg.h"
-#include "uidswap.h"
 #include "version.h"
 #include "ssherr.h"
 #include "myproposal.h"
@@ -599,22 +598,11 @@ main(int ac, char **av)
 	original_real_uid = getuid();
 	original_effective_uid = geteuid();
 
-	/*
-	 * Use uid-swapping to give up root privileges for the duration of
-	 * option processing.  We will re-instantiate the rights when we are
-	 * ready to create the privileged port, and will permanently drop
-	 * them when the port has been created (actually, when the connection
-	 * has been made, as we may need to create the port several times).
-	 */
-	PRIV_END;
-
-	/* If we are installed setuid root be careful to not drop core. */
-	if (original_real_uid != original_effective_uid) {
-		struct rlimit rlim;
-		rlim.rlim_cur = rlim.rlim_max = 0;
-		if (setrlimit(RLIMIT_CORE, &rlim) < 0)
-			fatal("setrlimit failed: %.100s", strerror(errno));
-	}
+	if (getuid() != geteuid())
+		fatal("ssh setuid not supported.");
+	if (getgid() != getegid())
+		fatal("ssh setgid not supported.");
+
 	/* Get user data. */
 	pw = getpwuid(original_real_uid);
 	if (!pw) {
@@ -1414,22 +1402,8 @@ main(int ac, char **av)
 			L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9);
 		}
 	}
-	/*
-	 * Get rid of any extra privileges that we may have.  We will no
-	 * longer need them.  Also, extra privileges could make it very hard
-	 * to read identity files and other non-world-readable files from the
-	 * user's home directory if it happens to be on a NFS volume where
-	 * root is mapped to nobody.
-	 */
-	if (original_effective_uid == 0) {
-		PRIV_START;
-		permanently_set_uid(pw);
-	}
 
-	/*
-	 * Now that we are back to our own permissions, create ~/.ssh
-	 * directory if it doesn't already exist.
-	 */
+	/* Create ~/.ssh * directory if it doesn't already exist. */
 	if (config == NULL) {
 		r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
 		    strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);