From c9c098b245d98e3d4d9fd82b93452dcc0d9491b0 Mon Sep 17 00:00:00 2001
From: markus <markus@openbsd.org>
Date: Tue, 30 May 2017 08:49:32 +0000
Subject: [PATCH] revise sshkey_load_public(): remove ssh1 related comments,
 remove extra open()/close() on keyfile, prevent leak of 'pub' if 'keyp' is
 NULL, replace strlcpy+cat with asprintf; ok djm@

---
 usr.bin/ssh/authfile.c | 44 ++++++++++++++++++++----------------------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/usr.bin/ssh/authfile.c b/usr.bin/ssh/authfile.c
index dd3500ba485..080eb801392 100644
--- a/usr.bin/ssh/authfile.c
+++ b/usr.bin/ssh/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.124 2017/04/30 23:10:43 djm Exp $ */
+/* $OpenBSD: authfile.c,v 1.125 2017/05/30 08:49:32 markus Exp $ */
 /*
  * Copyright (c) 2000, 2013 Markus Friedl.  All rights reserved.
  *
@@ -311,50 +311,48 @@ sshkey_try_load_public(struct sshkey *k, const char *filename, char **commentp)
 	return SSH_ERR_INVALID_FORMAT;
 }
 
-/* load public key from ssh v1 private or any pubkey file */
+/* load public key from any pubkey file */
 int
 sshkey_load_public(const char *filename, struct sshkey **keyp, char **commentp)
 {
 	struct sshkey *pub = NULL;
-	char file[PATH_MAX];
-	int r, fd;
+	char *file = NULL;
+	int r;
 
 	if (keyp != NULL)
 		*keyp = NULL;
 	if (commentp != NULL)
 		*commentp = NULL;
 
-	/* XXX should load file once and attempt to parse each format */
-
-	if ((fd = open(filename, O_RDONLY)) < 0)
-		goto skip;
-	close(fd);
-
-	/* try ssh2 public key */
 	if ((pub = sshkey_new(KEY_UNSPEC)) == NULL)
 		return SSH_ERR_ALLOC_FAIL;
 	if ((r = sshkey_try_load_public(pub, filename, commentp)) == 0) {
-		if (keyp != NULL)
+		if (keyp != NULL) {
 			*keyp = pub;
-		return 0;
+			pub = NULL;
+		}
+		r = 0;
+		goto out;
 	}
 	sshkey_free(pub);
 
-
- skip:
 	/* try .pub suffix */
-	if ((pub = sshkey_new(KEY_UNSPEC)) == NULL)
+	if (asprintf(&file, "%s.pub", filename) == -1)
 		return SSH_ERR_ALLOC_FAIL;
-	r = SSH_ERR_ALLOC_FAIL;	/* in case strlcpy or strlcat fail */
-	if ((strlcpy(file, filename, sizeof file) < sizeof(file)) &&
-	    (strlcat(file, ".pub", sizeof file) < sizeof(file)) &&
-	    (r = sshkey_try_load_public(pub, file, commentp)) == 0) {
-		if (keyp != NULL)
+	if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_try_load_public(pub, file, commentp)) == 0) {
+		if (keyp != NULL) {
 			*keyp = pub;
-		return 0;
+			pub = NULL;
+		}
+		r = 0;
 	}
+ out:
+	free(file);
 	sshkey_free(pub);
-
 	return r;
 }
 
-- 
2.20.1