--- Linux-PAM-0.99.6.2/modules/pam_selinux/pam_selinux.8.xml.select-context 2007-02-21 20:38:10.000000000 +0100
+++ Linux-PAM-0.99.6.2/modules/pam_selinux/pam_selinux.8.xml 2007-02-21 20:38:11.000000000 +0100
@@ -33,6 +33,9 @@
<arg choice="opt">
verbose
</arg>
+ <arg choice="opt">
+ select_context
+ </arg>
</cmdsynopsis>
</refsynopsisdiv>
@@ -118,6 +121,17 @@
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term>
+ <option>select_context</option>
+ </term>
+ <listitem>
+ <para>
+ Attempt to ask the user for a custom security context role.
+ If MLS is on ask also for sensitivity level.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
</refsect1>
--- Linux-PAM-0.99.6.2/modules/pam_selinux/pam_selinux.c.select-context 2007-02-21 20:38:10.000000000 +0100
+++ Linux-PAM-0.99.6.2/modules/pam_selinux/pam_selinux.c 2007-02-21 20:44:01.000000000 +0100
@@ -63,9 +63,64 @@
#include <selinux/selinux.h>
#include <selinux/get_context_list.h>
#include <selinux/flask.h>
+#include <selinux/av_permissions.h>
#include <selinux/selinux.h>
#include <selinux/context.h>
+#include <selinux/get_default_type.h>
+#ifdef HAVE_LIBAUDIT
+#include <libaudit.h>
+#include <sys/select.h>
+#include <errno.h>
+#endif
+
+/* Send audit message */
+static
+
+int send_audit_message(pam_handle_t *pamh, int success, security_context_t default_context,
+ security_context_t selected_context)
+{
+ int rc=0;
+#ifdef HAVE_LIBAUDIT
+ char *msg = NULL;
+ int audit_fd = audit_open();
+ security_context_t default_raw=NULL;
+ security_context_t selected_raw=NULL;
+ rc = -1;
+ if (audit_fd < 0) {
+ pam_syslog(pamh, LOG_ERR, _("Error connecting to audit system.\n"));
+ return rc;
+ }
+ if (selinux_trans_to_raw_context(default_context, &default_raw) < 0) {
+ pam_syslog(pamh, LOG_ERR, _("Error translating default context.\n"));
+ goto out;
+ }
+ if (selinux_trans_to_raw_context(selected_context, &selected_raw) < 0) {
+ pam_syslog(pamh, LOG_ERR, _("Error translating selected context.\n"));
+ goto out;
+ }
+ if (asprintf(&msg, "pam: default-context=%s selected-context=%s",
+ default_context ? default_raw : "?",
+ selected_context ? selected_raw : "?") < 0) {
+ pam_syslog(pamh, LOG_ERR, ("Error allocating memory.\n"));
+ goto out;
+ }
+ if (audit_log_user_message(audit_fd, AUDIT_USER_ROLE_CHANGE,
+ msg, NULL, NULL, NULL, success) <= 0) {
+ pam_syslog(pamh, LOG_ERR, _("Error sending audit message.\n"));
+ goto out;
+ }
+ rc = 0;
+ out:
+ free(msg);
+ freecon(default_raw);
+ free(selected_raw);
+ close(audit_fd);
+#else
+ pam_syslog(pamh, LOG_NOTICE, "pam: default-context=%s selected-context=%s success %d", default_context, selected_context, success);
+#endif
+ return rc;
+}
static int
send_text (pam_handle_t *pamh, const char *text, int debug)
{
@@ -79,69 +134,64 @@
* is responsible for freeing the responses.
*/
static int
-query_response (pam_handle_t *pamh, const char *text,
+query_response (pam_handle_t *pamh, const char *text, const char *def,
char **responses, int debug)
{
+ int rc;
+ if (def)
+ rc = pam_prompt (pamh, PAM_PROMPT_ECHO_ON, responses, "%s [%s] ", text, def);
+ else
+ rc = pam_prompt (pamh, PAM_PROMPT_ECHO_ON, responses, "%s ", text);
if (debug)
- pam_syslog(pamh, LOG_NOTICE, "%s", text);
-
- return pam_prompt (pamh, PAM_PROMPT_ECHO_ON, responses, "%s", text);
+ pam_syslog(pamh, LOG_NOTICE, "%s %s", text, responses[0]);
+ return rc;
}
static security_context_t
manual_context (pam_handle_t *pamh, const char *user, int debug)
{
- security_context_t newcon;
+ security_context_t newcon=NULL;
context_t new_context;
int mls_enabled = is_selinux_mls_enabled();
-
- char *responses;
+ char *type=NULL;
+ char *responses=NULL;
while (1) {
query_response(pamh,
- _("Would you like to enter a security context? [y] "),
+ _("Would you like to enter a security context? [N] "), NULL,
&responses,debug);
- if ((responses[0] == 'y') || (responses[0] == 'Y') ||
- (responses[0] == '\0') )
+ if ((responses[0] == 'y') || (responses[0] == 'Y'))
{
if (mls_enabled)
new_context = context_new ("user:role:type:level");
else
new_context = context_new ("user:role:type");
- _pam_drop(responses);
- /* Allow the user to enter each field of the context individually */
+ if (!new_context)
+ goto fail_set;
+
if (context_user_set (new_context, user))
- {
- context_free (new_context);
- return NULL;
- }
- query_response(pamh,_("role: "),&responses,debug);
- if (context_role_set (new_context, responses))
- {
- _pam_drop(responses);
- context_free (new_context);
- return NULL;
- }
+ goto fail_set;
+
_pam_drop(responses);
- query_response(pamh,_("type: "),&responses,debug);
- if (context_type_set (new_context, responses))
- {
- _pam_drop(responses);
- context_free (new_context);
- return NULL;
- }
+ /* Allow the user to enter each field of the context individually */
+ query_response(pamh,_("role:"), NULL, &responses,debug);
+ if (responses[0] != '\0') {
+ if (context_role_set (new_context, responses))
+ goto fail_set;
+ if (get_default_type(responses, &type))
+ goto fail_set;
+ if (context_type_set (new_context, type))
+ goto fail_set;
+ }
_pam_drop(responses);
if (mls_enabled)
{
- query_response(pamh,_("level: "),&responses,debug);
- if (context_range_set (new_context, responses))
- {
- _pam_drop(responses);
- context_free (new_context);
- return NULL;
- }
- _pam_drop(responses);
+ query_response(pamh,_("level:"), NULL, &responses,debug);
+ if (responses[0] != '\0') {
+ if (context_range_set (new_context, responses))
+ goto fail_set;
+ }
}
/* Get the string value of the context and see if it is valid. */
if (!security_check_context(context_str(new_context))) {
@@ -151,14 +201,125 @@
}
else
send_text(pamh,_("Not a valid security context"),debug);
+ context_free (new_context);
}
else {
_pam_drop(responses);
return NULL;
}
} /* end while */
+ fail_set:
+ free(type);
+ _pam_drop(responses);
+ context_free (new_context);
+ return NULL;
+}
+
+static int mls_range_allowed(pam_handle_t *pamh, security_context_t src, security_context_t dst, int debug)
+{
+ struct av_decision avd;
+ int retval;
+ unsigned int bit = CONTEXT__CONTAINS;
+ context_t src_context = context_new (src);
+ context_t dst_context = context_new (dst);
+ context_range_set(dst_context, context_range_get(src_context));
+ if (debug)
+ pam_syslog(pamh, LOG_NOTICE, "Checking if %s mls range valid for %s", dst, context_str(dst_context));
+
+ retval = security_compute_av(context_str(dst_context), dst, SECCLASS_CONTEXT, bit, &avd);
+ context_free(src_context);
+ context_free(dst_context);
+ if (retval || ((bit & avd.allowed) != bit))
+ return 0;
+
+ return 1;
+}
+
+static security_context_t
+config_context (pam_handle_t *pamh, security_context_t puser_context, int debug)
+{
+ security_context_t newcon=NULL;
+ context_t new_context;
+ int mls_enabled = is_selinux_mls_enabled();
+ char *responses=NULL;
+ char *type=NULL;
+ char resp_val = 0;
+
+ pam_prompt (pamh, PAM_TEXT_INFO, NULL, _("Default Security Context %s\n"), puser_context);
+
+ while (1) {
+ query_response(pamh,
+ _("Would you like to enter a different role or level?"), "n",
+ &responses,debug);
+
+ resp_val = responses[0];
+ _pam_drop(responses);
+ if ((resp_val == 'y') || (resp_val == 'Y'))
+ {
+ new_context = context_new(puser_context);
+
+ /* Allow the user to enter role and level individually */
+ query_response(pamh,_("role:"), context_role_get(new_context),
+ &responses, debug);
+ if (responses[0]) {
+ if (get_default_type(responses, &type)) {
+ pam_prompt (pamh, PAM_ERROR_MSG, NULL, _("No default type for role %s\n"), responses);
+ _pam_drop(responses);
+ continue;
+ } else {
+ if (context_role_set(new_context, responses))
+ goto fail_set;
+ if (context_type_set (new_context, type))
+ goto fail_set;
+ }
+ }
+ _pam_drop(responses);
+ if (mls_enabled)
+ {
+ query_response(pamh,_("level:"), context_range_get(new_context),
+ &responses, debug);
+ if (responses[0]) {
+ if (context_range_set(new_context, responses))
+ goto fail_set;
+ }
+ _pam_drop(responses);
+ }
+ if (debug)
+ pam_syslog(pamh, LOG_NOTICE, "Selected Security Context %s", context_str(new_context));
+
+ /* Get the string value of the context and see if it is valid. */
+ if (!security_check_context(context_str(new_context))) {
+ newcon = strdup(context_str(new_context));
+ context_free (new_context);
+
+ /* we have to check that this user is allowed to go into the
+ range they have specified ... role is tied to an seuser, so that'll
+ be checked at setexeccon time */
+ if (mls_enabled && !mls_range_allowed(pamh, puser_context, newcon, debug)) {
+ pam_syslog(pamh, LOG_NOTICE, "Security context %s is not allowed for %s", puser_context, newcon);
+
+
+ goto fail_range;
+ }
+ return newcon;
+ }
+ else
+ send_text(pamh,_("Not a valid security context"),debug);
+
+ context_free(new_context); /* next time around allocates another */
+ }
+ else
+ return strdup(puser_context);
+ } /* end while */
return NULL;
+
+ fail_set:
+ free(type);
+ _pam_drop(responses);
+ context_free (new_context);
+ fail_range:
+ return NULL;
}
static void
@@ -273,13 +434,15 @@
{
int i, debug = 0, ttys=1, has_tty=isatty(0);
int verbose=0, close_session=0;
+ int select_context = 0;
int ret = 0;
security_context_t* contextlist = NULL;
int num_contexts = 0;
- const void *username = NULL;
+ const char *username = NULL;
const void *tty = NULL;
char *seuser=NULL;
char *level=NULL;
+ security_context_t default_user_context=NULL;
/* Parse arguments. */
for (i = 0; i < argc; i++) {
@@ -295,6 +458,9 @@
if (strcmp(argv[i], "close") == 0) {
close_session = 1;
}
+ if (strcmp(argv[i], "select_context") == 0) {
+ select_context = 1;
+ }
}
if (debug)
@@ -307,7 +473,7 @@
if (!(selinux_enabled = is_selinux_enabled()>0) )
return PAM_SUCCESS;
- if (pam_get_item(pamh, PAM_USER, &username) != PAM_SUCCESS ||
+ if (pam_get_item(pamh, PAM_USER, (void *) &username) != PAM_SUCCESS ||
username == NULL) {
return PAM_USER_UNKNOWN;
}
@@ -319,19 +485,39 @@
&contextlist);
if (debug)
pam_syslog(pamh, LOG_DEBUG, "Username= %s SELinux User = %s Level= %s",
- (const char *)username, seuser, level);
+ username, seuser, level);
free(seuser);
free(level);
}
if (num_contexts > 0) {
- user_context = (security_context_t) strdup(contextlist[0]);
+ default_user_context=strdup(contextlist[0]);
freeconary(contextlist);
- } else {
+ if (default_user_context == NULL) {
+ pam_syslog(pamh, LOG_ERR, _("Out of memory"));
+ return PAM_AUTH_ERR;
+ }
+ user_context = default_user_context;
+ if (select_context && has_tty) {
+ user_context = config_context(pamh, default_user_context, debug);
+ if (user_context == NULL) {
+ send_audit_message(pamh, 0, default_user_context, default_user_context);
+ freecon(default_user_context);
+ pam_syslog(pamh, LOG_ERR, _("Unable to get valid context for %s"),
+ username);
+ pam_prompt (pamh, PAM_ERROR_MSG, NULL, _("Unable to get valid context for %s"), username);
+ if (security_getenforce() == 1)
+ return PAM_AUTH_ERR;
+ else
+ return PAM_SUCCESS;
+ }
+ }
+ }
+ else {
if (has_tty) {
- user_context = manual_context(pamh,username,debug);
+ user_context = manual_context(pamh,seuser,debug);
if (user_context == NULL) {
pam_syslog (pamh, LOG_ERR, "Unable to get valid context for %s",
- (const char *)username);
+ username);
if (security_getenforce() == 1)
return PAM_AUTH_ERR;
else
@@ -340,7 +526,7 @@
} else {
pam_syslog (pamh, LOG_ERR,
"Unable to get valid context for %s, No valid tty",
- (const char *)username);
+ username);
if (security_getenforce() == 1)
return PAM_AUTH_ERR;
else
@@ -371,6 +557,10 @@
ttyn=strdup(tty);
ttyn_context=security_label_tty(pamh,ttyn,user_context);
}
+ send_audit_message(pamh, 1, default_user_context, user_context);
+ if (default_user_context != user_context) {
+ freecon(default_user_context);
+ }
ret = setexeccon(user_context);
if (ret==0 && verbose) {
char msg[PATH_MAX];
@@ -381,7 +571,7 @@
if (ret) {
pam_syslog(pamh, LOG_ERR,
"Error! Unable to set %s executable context %s.",
- (const char *)username, user_context);
+ username, user_context);
if (security_getenforce() == 1) {
freecon(user_context);
return PAM_AUTH_ERR;
@@ -389,7 +579,7 @@
} else {
if (debug)
pam_syslog(pamh, LOG_NOTICE, "set %s security context to %s",
- (const char *)username, user_context);
+ username, user_context);
}
#ifdef HAVE_SETKEYCREATECON
ret = setkeycreatecon(user_context);
@@ -402,7 +592,7 @@
if (ret) {
pam_syslog(pamh, LOG_ERR,
"Error! Unable to set %s key creation context %s.",
- (const char *)username, user_context);
+ username, user_context);
if (security_getenforce() == 1) {
freecon(user_context);
return PAM_AUTH_ERR;
@@ -410,7 +600,7 @@
} else {
if (debug)
pam_syslog(pamh, LOG_NOTICE, "set %s key creation context to %s",
- (const char *)username, user_context);
+ username, user_context);
}
#endif
freecon(user_context);