You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
226 lines
6.9 KiB
226 lines
6.9 KiB
From 940747f88c16e029b69a74e80a2e94f65cb3e628 Mon Sep 17 00:00:00 2001
|
|
From: Thorsten Kukuk <kukuk@suse.com>
|
|
Date: Thu, 14 Nov 2024 10:27:28 +0100
|
|
Subject: [PATCH] pam_access: rework resolving of tokens as hostname
|
|
|
|
* modules/pam_access/pam_access.c: separate resolving of IP addresses
|
|
from hostnames. Don't resolve TTYs or display variables as hostname
|
|
(#834).
|
|
Add "nodns" option to disallow resolving of tokens as hostname.
|
|
* modules/pam_access/pam_access.8.xml: document nodns option
|
|
* modules/pam_access/access.conf.5.xml: document that hostnames should
|
|
be written as FQHN.
|
|
---
|
|
modules/pam_access/access.conf.5.xml | 4 ++
|
|
modules/pam_access/pam_access.8.xml | 46 ++++++++++++------
|
|
modules/pam_access/pam_access.c | 72 +++++++++++++++++++++++++++-
|
|
3 files changed, 105 insertions(+), 17 deletions(-)
|
|
|
|
diff --git a/modules/pam_access/access.conf.5.xml b/modules/pam_access/access.conf.5.xml
|
|
index 0b93db00..10b8ba92 100644
|
|
--- a/modules/pam_access/access.conf.5.xml
|
|
+++ b/modules/pam_access/access.conf.5.xml
|
|
@@ -233,6 +233,10 @@
|
|
An IPv6 link local host address must contain the interface
|
|
identifier. IPv6 link local network/netmask is not supported.
|
|
</para>
|
|
+ <para>
|
|
+ Hostnames should be written as Fully-Qualified Host Name (FQHN) to avoid
|
|
+ confusion with device names or PAM service names.
|
|
+ </para>
|
|
</refsect1>
|
|
|
|
<refsect1 xml:id="access.conf-see_also">
|
|
diff --git a/modules/pam_access/pam_access.8.xml b/modules/pam_access/pam_access.8.xml
|
|
index c991d7a0..71a4f7ee 100644
|
|
--- a/modules/pam_access/pam_access.8.xml
|
|
+++ b/modules/pam_access/pam_access.8.xml
|
|
@@ -22,11 +22,14 @@
|
|
<arg choice="opt" rep="norepeat">
|
|
debug
|
|
</arg>
|
|
+ <arg choice="opt" rep="norepeat">
|
|
+ noaudit
|
|
+ </arg>
|
|
<arg choice="opt" rep="norepeat">
|
|
nodefgroup
|
|
</arg>
|
|
<arg choice="opt" rep="norepeat">
|
|
- noaudit
|
|
+ nodns
|
|
</arg>
|
|
<arg choice="opt" rep="norepeat">
|
|
quiet_log
|
|
@@ -132,6 +135,33 @@
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
+ <varlistentry>
|
|
+ <term>
|
|
+ nodefgroup
|
|
+ </term>
|
|
+ <listitem>
|
|
+ <para>
|
|
+ User tokens which are not enclosed in parentheses will not be
|
|
+ matched against the group database. The backwards compatible default is
|
|
+ to try the group database match even for tokens not enclosed
|
|
+ in parentheses.
|
|
+ </para>
|
|
+ </listitem>
|
|
+ </varlistentry>
|
|
+
|
|
+ <varlistentry>
|
|
+ <term>
|
|
+ nodns
|
|
+ </term>
|
|
+ <listitem>
|
|
+ <para>
|
|
+ Do not try to resolve tokens as hostnames, only IPv4 and IPv6
|
|
+ addresses will be resolved. Which means to allow login from a
|
|
+ remote host, the IP addresses need to be specified in <filename>access.conf</filename>.
|
|
+ </para>
|
|
+ </listitem>
|
|
+ </varlistentry>
|
|
+
|
|
<varlistentry>
|
|
<term>
|
|
quiet_log
|
|
@@ -185,20 +215,6 @@
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
- <varlistentry>
|
|
- <term>
|
|
- nodefgroup
|
|
- </term>
|
|
- <listitem>
|
|
- <para>
|
|
- User tokens which are not enclosed in parentheses will not be
|
|
- matched against the group database. The backwards compatible default is
|
|
- to try the group database match even for tokens not enclosed
|
|
- in parentheses.
|
|
- </para>
|
|
- </listitem>
|
|
- </varlistentry>
|
|
-
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
diff --git a/modules/pam_access/pam_access.c b/modules/pam_access/pam_access.c
|
|
index 48e7c7e9..109115e9 100644
|
|
--- a/modules/pam_access/pam_access.c
|
|
+++ b/modules/pam_access/pam_access.c
|
|
@@ -100,6 +100,7 @@ struct login_info {
|
|
int only_new_group_syntax; /* Only allow group entries of the form "(xyz)" */
|
|
int noaudit; /* Do not audit denials */
|
|
int quiet_log; /* Do not log denials */
|
|
+ int nodns; /* Do not try to resolve tokens as hostnames */
|
|
const char *fs; /* field separator */
|
|
const char *sep; /* list-element separator */
|
|
int from_remote_host; /* If PAM_RHOST was used for from */
|
|
@@ -154,6 +155,8 @@ parse_args(pam_handle_t *pamh, struct login_info *loginfo,
|
|
loginfo->noaudit = YES;
|
|
} else if (strcmp (argv[i], "quiet_log") == 0) {
|
|
loginfo->quiet_log = YES;
|
|
+ } else if (strcmp (argv[i], "nodns") == 0) {
|
|
+ loginfo->nodns = YES;
|
|
} else {
|
|
pam_syslog(pamh, LOG_ERR, "unrecognized option [%s]", argv[i]);
|
|
}
|
|
@@ -820,7 +823,7 @@ remote_match (pam_handle_t *pamh, char *tok, struct login_info *item)
|
|
if ((str_len = strlen(string)) > tok_len
|
|
&& strcasecmp(tok, string + str_len - tok_len) == 0)
|
|
return YES;
|
|
- } else if (tok[tok_len - 1] == '.') { /* internet network numbers (end with ".") */
|
|
+ } else if (tok[tok_len - 1] == '.') { /* internet network numbers/subnet (end with ".") */
|
|
struct addrinfo hint;
|
|
|
|
memset (&hint, '\0', sizeof (hint));
|
|
@@ -895,6 +898,39 @@ string_match (pam_handle_t *pamh, const char *tok, const char *string,
|
|
}
|
|
|
|
|
|
+static int
|
|
+is_device (pam_handle_t *pamh, const char *tok)
|
|
+{
|
|
+ struct stat st;
|
|
+ const char *dev = "/dev/";
|
|
+ char *devname;
|
|
+
|
|
+ devname = malloc (strlen(dev) + strlen (tok) + 1);
|
|
+ if (devname == NULL) {
|
|
+ pam_syslog(pamh, LOG_ERR, "Cannot allocate memory for device name: %m");
|
|
+ /*
|
|
+ * We should return an error and abort, but pam_access has no good
|
|
+ * error handling.
|
|
+ */
|
|
+ return NO;
|
|
+ }
|
|
+
|
|
+ char *cp = stpcpy (devname, dev);
|
|
+ strcpy (cp, tok);
|
|
+
|
|
+ if (lstat(devname, &st) != 0)
|
|
+ {
|
|
+ free (devname);
|
|
+ return NO;
|
|
+ }
|
|
+ free (devname);
|
|
+
|
|
+ if (S_ISCHR(st.st_mode))
|
|
+ return YES;
|
|
+
|
|
+ return NO;
|
|
+}
|
|
+
|
|
/* network_netmask_match - match a string against one token
|
|
* where string is a hostname or ip (v4,v6) address and tok
|
|
* represents either a hostname, a single ip (v4,v6) address
|
|
@@ -956,10 +992,42 @@ network_netmask_match (pam_handle_t *pamh,
|
|
return NO;
|
|
}
|
|
}
|
|
+ else if (isipaddr(tok, NULL, NULL) == YES)
|
|
+ {
|
|
+ if (getaddrinfo (tok, NULL, NULL, &ai) != 0)
|
|
+ {
|
|
+ if (item->debug)
|
|
+ pam_syslog(pamh, LOG_DEBUG, "cannot resolve IP address \"%s\"", tok);
|
|
+
|
|
+ return NO;
|
|
+ }
|
|
+ netmask_ptr = NULL;
|
|
+ }
|
|
+ else if (item->nodns)
|
|
+ {
|
|
+ /* Only hostnames are left, which we would need to resolve via DNS */
|
|
+ return NO;
|
|
+ }
|
|
else
|
|
{
|
|
+ /* Bail out on X11 Display entries and ttys. */
|
|
+ if (tok[0] == ':')
|
|
+ {
|
|
+ if (item->debug)
|
|
+ pam_syslog (pamh, LOG_DEBUG,
|
|
+ "network_netmask_match: tok=%s is X11 display", tok);
|
|
+ return NO;
|
|
+ }
|
|
+ if (is_device (pamh, tok))
|
|
+ {
|
|
+ if (item->debug)
|
|
+ pam_syslog (pamh, LOG_DEBUG,
|
|
+ "network_netmask_match: tok=%s is a TTY", tok);
|
|
+ return NO;
|
|
+ }
|
|
+
|
|
/*
|
|
- * It is either an IP address or a hostname.
|
|
+ * It is most likely a hostname.
|
|
* Let getaddrinfo sort everything out
|
|
*/
|
|
if (getaddrinfo (tok, NULL, NULL, &ai) != 0)
|
|
--
|
|
2.47.0
|
|
|