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authordjm@openbsd.org <djm@openbsd.org>2016-11-06 05:46:37 +0000
committerDamien Miller <djm@mindrot.org>2016-11-06 16:48:29 +1100
commit010359b32659f455fddd2bd85fd7cc4d7a3b994a (patch)
tree3e7256e7255cac73e3ab1e9e3bde697a66b60865
parentefb494e81d1317209256b38b49f4280897c61e69 (diff)
upstream commit
Validate address ranges for AllowUser/DenyUsers at configuration load time and refuse to accept bad ones. It was previously possible to specify invalid CIDR address ranges (e.g. djm@127.1.2.3/55) and these would always match. Thanks to Laurence Parry for a detailed bug report. ok markus (for a previous diff version) Upstream-ID: 9dfcdd9672b06e65233ea4434c38226680d40bfb
-rw-r--r--auth.c22
-rw-r--r--match.c21
-rw-r--r--servconf.c8
3 files changed, 38 insertions, 13 deletions
diff --git a/auth.c b/auth.c
index b6a4402..f7c1e7f 100644
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.116 2016/08/13 17:47:41 markus Exp $ */
+/* $OpenBSD: auth.c,v 1.117 2016/11/06 05:46:37 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
@@ -103,6 +103,7 @@ allowed_user(struct passwd * pw)
struct stat st;
const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
u_int i;
+ int r;
#ifdef USE_SHADOW
struct spwd *spw = NULL;
#endif
@@ -192,8 +193,12 @@ allowed_user(struct passwd * pw)
/* Return false if user is listed in DenyUsers */
if (options.num_deny_users > 0) {
for (i = 0; i < options.num_deny_users; i++)
- if (match_user(pw->pw_name, hostname, ipaddr,
- options.deny_users[i])) {
+ r = match_user(pw->pw_name, hostname, ipaddr,
+ options.deny_users[i]);
+ if (r < 0) {
+ fatal("Invalid DenyUsers pattern \"%.100s\"",
+ options.deny_users[i]);
+ } else if (r != 1) {
logit("User %.100s from %.100s not allowed "
"because listed in DenyUsers",
pw->pw_name, hostname);
@@ -202,10 +207,15 @@ allowed_user(struct passwd * pw)
}
/* Return false if AllowUsers isn't empty and user isn't listed there */
if (options.num_allow_users > 0) {
- for (i = 0; i < options.num_allow_users; i++)
- if (match_user(pw->pw_name, hostname, ipaddr,
- options.allow_users[i]))
+ for (i = 0; i < options.num_allow_users; i++) {
+ r = match_user(pw->pw_name, hostname, ipaddr,
+ options.allow_users[i]);
+ if (r < 0) {
+ fatal("Invalid AllowUsers pattern \"%.100s\"",
+ options.allow_users[i]);
+ } else if (r == 1)
break;
+ }
/* i < options.num_allow_users iff we break for loop */
if (i >= options.num_allow_users) {
logit("User %.100s from %.100s not allowed because "
diff --git a/match.c b/match.c
index b29a30e..c15dcd1 100644
--- a/match.c
+++ b/match.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: match.c,v 1.32 2016/09/21 16:55:42 djm Exp $ */
+/* $OpenBSD: match.c,v 1.33 2016/11/06 05:46:37 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -191,11 +191,10 @@ match_host_and_ip(const char *host, const char *ipaddr,
{
int mhost, mip;
- /* error in ipaddr match */
if ((mip = addr_match_list(ipaddr, patterns)) == -2)
- return -1;
- else if (mip == -1) /* negative ip address match */
- return 0;
+ return -1; /* error in ipaddr match */
+ else if (host == NULL || ipaddr == NULL || mip == -1)
+ return 0; /* negative ip address match, or testing pattern */
/* negative hostname match */
if ((mhost = match_hostname(host, patterns)) == -1)
@@ -207,7 +206,9 @@ match_host_and_ip(const char *host, const char *ipaddr,
}
/*
- * match user, user@host_or_ip, user@host_or_ip_list against pattern
+ * Match user, user@host_or_ip, user@host_or_ip_list against pattern.
+ * If user, host and ipaddr are all NULL then validate pattern/
+ * Returns -1 on invalid pattern, 0 on no match, 1 on match.
*/
int
match_user(const char *user, const char *host, const char *ipaddr,
@@ -216,6 +217,14 @@ match_user(const char *user, const char *host, const char *ipaddr,
char *p, *pat;
int ret;
+ /* test mode */
+ if (user == NULL && host == NULL && ipaddr == NULL) {
+ if ((p = strchr(pattern, '@')) != NULL &&
+ match_host_and_ip(NULL, NULL, p + 1) < 0)
+ return -1;
+ return 0;
+ }
+
if ((p = strchr(pattern,'@')) == NULL)
return match_pattern(user, pattern);
diff --git a/servconf.c b/servconf.c
index 35abec4..a18ebb5 100644
--- a/servconf.c
+++ b/servconf.c
@@ -1,5 +1,5 @@
-/* $OpenBSD: servconf.c,v 1.298 2016/10/24 01:09:17 dtucker Exp $ */
+/* $OpenBSD: servconf.c,v 1.299 2016/11/06 05:46:37 djm Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
@@ -1366,6 +1366,9 @@ process_server_config_line(ServerOptions *options, char *line,
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%s line %d: too many allow users.",
filename, linenum);
+ if (match_user(NULL, NULL, NULL, arg) == -1)
+ fatal("%s line %d: invalid AllowUsers pattern: "
+ "\"%.100s\"", filename, linenum, arg);
if (!*activep)
continue;
options->allow_users[options->num_allow_users++] =
@@ -1378,6 +1381,9 @@ process_server_config_line(ServerOptions *options, char *line,
if (options->num_deny_users >= MAX_DENY_USERS)
fatal("%s line %d: too many deny users.",
filename, linenum);
+ if (match_user(NULL, NULL, NULL, arg) == -1)
+ fatal("%s line %d: invalid DenyUsers pattern: "
+ "\"%.100s\"", filename, linenum, arg);
if (!*activep)
continue;
options->deny_users[options->num_deny_users++] =