From fffe3169bb490c4b010b168c639aa6f9b2ec0c52 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pavel=20B=C5=99ezina?= <pbrezina@redhat.com>
Date: Thu, 10 Dec 2020 22:05:30 +0100
Subject: [PATCH 26/27] pam: add pam_gssapi_check_upn option
:config: Added `pam_gssapi_check_upn` to enforce authentication
only with principal that can be associated with target user.
Reviewed-by: Robbie Harwood <rharwood@redhat.com>
Reviewed-by: Sumit Bose <sbose@redhat.com>
---
src/confdb/confdb.c | 10 ++++++++++
src/confdb/confdb.h | 2 ++
src/config/SSSDConfig/sssdoptions.py | 1 +
src/config/SSSDConfigTest.py | 6 ++++--
src/config/cfg_rules.ini | 3 +++
src/config/etc/sssd.api.conf | 2 ++
src/db/sysdb_subdomains.c | 12 ++++++++++++
src/man/sssd.conf.5.xml | 26 ++++++++++++++++++++++++++
src/responder/pam/pamsrv.c | 9 +++++++++
src/responder/pam/pamsrv.h | 1 +
10 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/src/confdb/confdb.c b/src/confdb/confdb.c
index 7f1956d6d..2881ce5da 100644
--- a/src/confdb/confdb.c
+++ b/src/confdb/confdb.c
@@ -1593,6 +1593,16 @@ static int confdb_get_domain_internal(struct confdb_ctx *cdb,
}
}
+ tmp = ldb_msg_find_attr_as_string(res->msgs[0], CONFDB_PAM_GSSAPI_CHECK_UPN,
+ NULL);
+ if (tmp != NULL) {
+ domain->gssapi_check_upn = talloc_strdup(domain, tmp);
+ if (domain->gssapi_check_upn == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+ }
+
domain->has_views = false;
domain->view_name = NULL;
diff --git a/src/confdb/confdb.h b/src/confdb/confdb.h
index 7a3bc8bb5..036f9ecad 100644
--- a/src/confdb/confdb.h
+++ b/src/confdb/confdb.h
@@ -145,6 +145,7 @@
#define CONFDB_PAM_P11_URI "p11_uri"
#define CONFDB_PAM_INITGROUPS_SCHEME "pam_initgroups_scheme"
#define CONFDB_PAM_GSSAPI_SERVICES "pam_gssapi_services"
+#define CONFDB_PAM_GSSAPI_CHECK_UPN "pam_gssapi_check_upn"
/* SUDO */
#define CONFDB_SUDO_CONF_ENTRY "config/sudo"
@@ -435,6 +436,7 @@ struct sss_domain_info {
/* List of PAM services that are allowed to authenticate with GSSAPI. */
char **gssapi_services;
+ char *gssapi_check_upn; /* true | false | NULL */
};
/**
diff --git a/src/config/SSSDConfig/sssdoptions.py b/src/config/SSSDConfig/sssdoptions.py
index f59fe8d9f..5da52a937 100644
--- a/src/config/SSSDConfig/sssdoptions.py
+++ b/src/config/SSSDConfig/sssdoptions.py
@@ -105,6 +105,7 @@ class SSSDOptions(object):
'p11_uri': _('PKCS#11 URI to restrict the selection of devices for Smartcard authentication'),
'pam_initgroups_scheme' : _('When shall the PAM responder force an initgroups request'),
'pam_gssapi_services' : _('List of PAM services that are allowed to authenticate with GSSAPI.'),
+ 'pam_gssapi_check_upn' : _('Whether to match authenticated UPN with target user'),
# [sudo]
'sudo_timed': _('Whether to evaluate the time-based attributes in sudo rules'),
diff --git a/src/config/SSSDConfigTest.py b/src/config/SSSDConfigTest.py
index 21fffe1b6..ea4e4f6c9 100755
--- a/src/config/SSSDConfigTest.py
+++ b/src/config/SSSDConfigTest.py
@@ -654,7 +654,8 @@ class SSSDConfigTestSSSDDomain(unittest.TestCase):
're_expression',
'cached_auth_timeout',
'auto_private_groups',
- 'pam_gssapi_services']
+ 'pam_gssapi_services',
+ 'pam_gssapi_check_upn']
self.assertTrue(type(options) == dict,
"Options should be a dictionary")
@@ -1032,7 +1033,8 @@ class SSSDConfigTestSSSDDomain(unittest.TestCase):
're_expression',
'cached_auth_timeout',
'auto_private_groups',
- 'pam_gssapi_services']
+ 'pam_gssapi_services',
+ 'pam_gssapi_check_upn']
self.assertTrue(type(options) == dict,
"Options should be a dictionary")
diff --git a/src/config/cfg_rules.ini b/src/config/cfg_rules.ini
index c6dfd5648..6642c6321 100644
--- a/src/config/cfg_rules.ini
+++ b/src/config/cfg_rules.ini
@@ -140,6 +140,7 @@ option = p11_wait_for_card_timeout
option = p11_uri
option = pam_initgroups_scheme
option = pam_gssapi_services
+option = pam_gssapi_check_upn
[rule/allowed_sudo_options]
validator = ini_allowed_options
@@ -439,6 +440,7 @@ option = full_name_format
option = re_expression
option = auto_private_groups
option = pam_gssapi_services
+option = pam_gssapi_check_upn
#Entry cache timeouts
option = entry_cache_user_timeout
@@ -834,6 +836,7 @@ option = ad_site
option = use_fully_qualified_names
option = auto_private_groups
option = pam_gssapi_services
+option = pam_gssapi_check_upn
[rule/sssd_checks]
validator = sssd_checks
diff --git a/src/config/etc/sssd.api.conf b/src/config/etc/sssd.api.conf
index f46f3c46d..d3cad7380 100644
--- a/src/config/etc/sssd.api.conf
+++ b/src/config/etc/sssd.api.conf
@@ -81,6 +81,7 @@ p11_wait_for_card_timeout = int, None, false
p11_uri = str, None, false
pam_initgroups_scheme = str, None, false
pam_gssapi_services = str, None, false
+pam_gssapi_check_upn = bool, None, false
[sudo]
# sudo service
@@ -201,6 +202,7 @@ full_name_format = str, None, false
re_expression = str, None, false
auto_private_groups = str, None, false
pam_gssapi_services = str, None, false
+pam_gssapi_check_upn = bool, None, false
#Entry cache timeouts
entry_cache_user_timeout = int, None, false
diff --git a/src/db/sysdb_subdomains.c b/src/db/sysdb_subdomains.c
index bfc6df0f5..03ba12164 100644
--- a/src/db/sysdb_subdomains.c
+++ b/src/db/sysdb_subdomains.c
@@ -254,6 +254,18 @@ check_subdom_config_file(struct confdb_ctx *confdb,
goto done;
}
+ /* allow to set pam_gssapi_check_upn */
+ ret = confdb_get_string(confdb, subdomain, sd_conf_path,
+ CONFDB_PAM_GSSAPI_CHECK_UPN,
+ subdomain->parent->gssapi_check_upn,
+ &subdomain->gssapi_check_upn);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_OP_FAILURE,
+ "Failed to get %s option for the subdomain: %s\n",
+ CONFDB_PAM_GSSAPI_CHECK_UPN, subdomain->name);
+ goto done;
+ }
+
ret = EOK;
done:
talloc_free(tmp_ctx);
diff --git a/src/man/sssd.conf.5.xml b/src/man/sssd.conf.5.xml
index db9dd4677..d637e2eaa 100644
--- a/src/man/sssd.conf.5.xml
+++ b/src/man/sssd.conf.5.xml
@@ -1735,6 +1735,31 @@ pam_gssapi_services = sudo, sudo-i
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term>pam_gssapi_check_upn</term>
+ <listitem>
+ <para>
+ If True, SSSD will require that the Kerberos user
+ principal that successfully authenticated through
+ GSSAPI can be associated with the user who is being
+ authenticated. Authentication will fail if the check
+ fails.
+ </para>
+ <para>
+ If False, every user that is able to obtained
+ required service ticket will be authenticated.
+ </para>
+ <para>
+ Note: This option can also be set per-domain which
+ overwrites the value in [pam] section. It can also
+ be set for trusted domain which overwrites the value
+ in the domain section.
+ </para>
+ <para>
+ Default: True
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
</refsect2>
@@ -3810,6 +3835,7 @@ ldap_user_extra_attrs = phone:telephoneNumber
<para>ad_site,</para>
<para>use_fully_qualified_names</para>
<para>pam_gssapi_services</para>
+ <para>pam_gssapi_check_upn</para>
<para>
For more details about these options see their individual description
in the manual page.
diff --git a/src/responder/pam/pamsrv.c b/src/responder/pam/pamsrv.c
index 0492569c7..0db2824ff 100644
--- a/src/responder/pam/pamsrv.c
+++ b/src/responder/pam/pamsrv.c
@@ -348,6 +348,15 @@ static int pam_process_init(TALLOC_CTX *mem_ctx,
}
}
+ ret = confdb_get_bool(pctx->rctx->cdb, CONFDB_PAM_CONF_ENTRY,
+ CONFDB_PAM_GSSAPI_CHECK_UPN, true,
+ &pctx->gssapi_check_upn);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_FATAL_FAILURE, "Failed to read %s [%d]: %s\n",
+ CONFDB_PAM_GSSAPI_CHECK_UPN, ret, sss_strerror(ret));
+ goto done;
+ }
+
/* The responder is initialized. Now tell it to the monitor. */
ret = sss_monitor_service_init(rctx, rctx->ev, SSS_BUS_PAM,
SSS_PAM_SBUS_SERVICE_NAME,
diff --git a/src/responder/pam/pamsrv.h b/src/responder/pam/pamsrv.h
index 730dee288..bf4dd75b0 100644
--- a/src/responder/pam/pamsrv.h
+++ b/src/responder/pam/pamsrv.h
@@ -65,6 +65,7 @@ struct pam_ctx {
/* List of PAM services that are allowed to authenticate with GSSAPI. */
char **gssapi_services;
+ bool gssapi_check_upn;
};
struct pam_auth_req {
--
2.21.3