svn commit: r358070 - head/lib/libpam/modules/pam_login_access
Cy Schubert
cy at FreeBSD.org
Tue Feb 18 11:27:10 UTC 2020
Author: cy
Date: Tue Feb 18 11:27:08 2020
New Revision: 358070
URL: https://svnweb.freebsd.org/changeset/base/358070
Log:
This commit makes significant changes to pam_login_access(8) to bring it
up to par with the Linux pam_access(8).
Like the Linux pam_access(8) our pam_login_access(8) is a service module
for pam(3) that allows a administrator to limit access from specified
remote hosts or terminals. Unlike the Linux pam_access, pam_login_access
is missing some features which are added by this commit:
Access file can now be specified. The default remains /etc/access.conf.
The syntax is consistent with Linux pam_access.
By default usernames are matched. If the username fails to match a match
against a group name is attempted. The new nodefgroup module option will
only match a username and no attempt to match a group name is made.
Group names must be specified in brackets, "()" when nodefgroup is
specified. Otherwise the old backward compatible behavior is used.
This is consistent with Linux pam_access.
A new field separator module option allows the replacement of the default
colon (:) with any other character. This facilitates potential future
specification of X displays. This is also consistent with Linux pam_access.
A new list separator module option to replace the default space/comma/tab
with another character. This too is consistent with Linux pam_access.
Linux pam_access options not implemented in this commit are the debug
and audit options. These will be implemented at a later date.
Reviewed by: bjk, bcr (for manpages)
Approved by: des (blanket, implicit)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D23198
Modified:
head/lib/libpam/modules/pam_login_access/login.access.5
head/lib/libpam/modules/pam_login_access/login_access.c
head/lib/libpam/modules/pam_login_access/pam_login_access.8
head/lib/libpam/modules/pam_login_access/pam_login_access.c
head/lib/libpam/modules/pam_login_access/pam_login_access.h
Modified: head/lib/libpam/modules/pam_login_access/login.access.5
==============================================================================
--- head/lib/libpam/modules/pam_login_access/login.access.5 Tue Feb 18 11:27:05 2020 (r358069)
+++ head/lib/libpam/modules/pam_login_access/login.access.5 Tue Feb 18 11:27:08 2020 (r358070)
@@ -1,7 +1,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd January 27, 2020
+.Dd January 30, 2020
.Dt LOGIN.ACCESS 5
.Os
.Sh NAME
@@ -34,6 +34,13 @@ character.
.Pp
The second field should be a list of one or more login names,
group names, or ALL (always matches).
+Group names must be enclosed in
+parentheses if the pam module specification for
+.Pa pam_login_access
+specifies the
+.Pa nodefgroup
+option.
+Otherwise, group names will only match if no usernames match.
.Pp
The third field should be a list
of one or more tty names (for non-networked logins), host names, domain
Modified: head/lib/libpam/modules/pam_login_access/login_access.c
==============================================================================
--- head/lib/libpam/modules/pam_login_access/login_access.c Tue Feb 18 11:27:05 2020 (r358069)
+++ head/lib/libpam/modules/pam_login_access/login_access.c Tue Feb 18 11:27:08 2020 (r358070)
@@ -31,29 +31,26 @@ __FBSDID("$FreeBSD$");
#include "pam_login_access.h"
-#define _PATH_LOGACCESS "/etc/login.access"
-
- /* Delimiters for fields and for lists of users, ttys or hosts. */
-
-static char fs[] = ":"; /* field separator */
-static char sep[] = ", \t"; /* list-element separator */
-
/* Constants to be used in assignments only, not in comparisons... */
#define YES 1
#define NO 0
-static int from_match(const char *, const char *);
+static int from_match(const char *, const char *, struct pam_login_access_options *);
static int list_match(char *, const char *,
- int (*)(const char *, const char *));
+ int (*)(const char *, const char *,
+ struct pam_login_access_options *),
+ struct pam_login_access_options *);
static int netgroup_match(const char *, const char *, const char *);
static int string_match(const char *, const char *);
-static int user_match(const char *, const char *);
+static int user_match(const char *, const char *, struct pam_login_access_options *);
+static int group_match(const char *, const char *);
/* login_access - match username/group and host/tty with access control file */
int
-login_access(const char *user, const char *from)
+login_access(const char *user, const char *from,
+ struct pam_login_access_options *login_access_opts)
{
FILE *fp;
char line[BUFSIZ];
@@ -63,6 +60,7 @@ login_access(const char *user, const char *from)
int match = NO;
int end;
int lineno = 0; /* for diagnostics */
+ const char *fieldsep = login_access_opts->fieldsep;
/*
* Process the table one line at a time and stop at the first match.
@@ -72,12 +70,12 @@ login_access(const char *user, const char *from)
* non-existing table means no access control.
*/
- if ((fp = fopen(_PATH_LOGACCESS, "r")) != NULL) {
+ if ((fp = fopen(login_access_opts->accessfile, "r")) != NULL) {
while (!match && fgets(line, sizeof(line), fp)) {
lineno++;
if (line[end = strlen(line) - 1] != '\n') {
syslog(LOG_ERR, "%s: line %d: missing newline or line too long",
- _PATH_LOGACCESS, lineno);
+ login_access_opts->accessfile, lineno);
continue;
}
if (line[0] == '#')
@@ -87,25 +85,25 @@ login_access(const char *user, const char *from)
line[end] = 0; /* strip trailing whitespace */
if (line[0] == 0) /* skip blank lines */
continue;
- if (!(perm = strtok(line, fs))
- || !(users = strtok((char *) 0, fs))
- || !(froms = strtok((char *) 0, fs))
- || strtok((char *) 0, fs)) {
- syslog(LOG_ERR, "%s: line %d: bad field count", _PATH_LOGACCESS,
+ if (!(perm = strtok(line, fieldsep))
+ || !(users = strtok((char *) 0, fieldsep))
+ || !(froms = strtok((char *) 0, fieldsep))
+ || strtok((char *) 0, fieldsep)) {
+ syslog(LOG_ERR, "%s: line %d: bad field count", login_access_opts->accessfile,
lineno);
continue;
}
if (perm[0] != '+' && perm[0] != '-') {
- syslog(LOG_ERR, "%s: line %d: bad first field", _PATH_LOGACCESS,
+ syslog(LOG_ERR, "%s: line %d: bad first field", login_access_opts->accessfile,
lineno);
continue;
}
- match = (list_match(froms, from, from_match)
- && list_match(users, user, user_match));
+ match = (list_match(froms, from, from_match, login_access_opts)
+ && list_match(users, user, user_match, login_access_opts));
}
(void) fclose(fp);
} else if (errno != ENOENT) {
- syslog(LOG_ERR, "cannot open %s: %m", _PATH_LOGACCESS);
+ syslog(LOG_ERR, "cannot open %s: %m", login_access_opts->accessfile);
}
return (match == 0 || (line[0] == '+'));
}
@@ -114,10 +112,12 @@ login_access(const char *user, const char *from)
static int
list_match(char *list, const char *item,
- int (*match_fn)(const char *, const char *))
+ int (*match_fn)(const char *, const char *, struct pam_login_access_options *),
+ struct pam_login_access_options *login_access_opts)
{
char *tok;
int match = NO;
+ const char *listsep = login_access_opts->listsep;
/*
* Process tokens one at a time. We have exhausted all possible matches
@@ -126,19 +126,22 @@ list_match(char *list, const char *item,
* the match is affected by any exceptions.
*/
- for (tok = strtok(list, sep); tok != NULL; tok = strtok((char *) 0, sep)) {
+ for (tok = strtok(list, listsep); tok != NULL; tok = strtok((char *) 0, listsep)) {
if (strcmp(tok, "EXCEPT") == 0) /* EXCEPT: give up */
break;
- if ((match = (*match_fn)(tok, item)) != 0) /* YES */
+ if ((match = (*match_fn)(tok, item, login_access_opts)) != 0) /* YES */
break;
}
/* Process exceptions to matches. */
if (match != NO) {
- while ((tok = strtok((char *) 0, sep)) && strcmp(tok, "EXCEPT"))
+ while ((tok = strtok((char *) 0, listsep)) && strcmp(tok, "EXCEPT")) {
/* VOID */ ;
- if (tok == NULL || list_match((char *) 0, item, match_fn) == NO)
- return (match);
+ if (tok == NULL || list_match((char *) 0, item, match_fn,
+ login_access_opts) == NO) {
+ return (match);
+ }
+ }
}
return (NO);
}
@@ -170,17 +173,50 @@ netgroup_match(const char *group, const char *machine,
return (NO);
}
-/* user_match - match a username against one token */
+/* group_match - match a group against one token */
-static int
-user_match(const char *tok, const char *string)
+int
+group_match(const char *tok, const char *username)
{
struct group *group;
struct passwd *passwd;
gid_t *grouplist;
- int ngroups = NGROUPS;
- int i;
+ int i, ret, ngroups = NGROUPS;
+ if ((passwd = getpwnam(username)) == NULL)
+ return (NO);
+ errno = 0;
+ if ((group = getgrnam(tok)) == NULL) {
+ if (errno != 0)
+ syslog(LOG_ERR, "getgrnam() failed for %s: %s", username, strerror(errno));
+ else
+ syslog(LOG_NOTICE, "group not found: %s", username);
+ return (NO);
+ }
+ if ((grouplist = calloc(ngroups, sizeof(gid_t))) == NULL) {
+ syslog(LOG_ERR, "cannot allocate memory for grouplist: %s", username);
+ return (NO);
+ }
+ ret = NO;
+ if (getgrouplist(username, passwd->pw_gid, grouplist, &ngroups) != 0)
+ syslog(LOG_ERR, "getgrouplist() failed for %s", username);
+ for (i = 0; i < ngroups; i++)
+ if (grouplist[i] == group->gr_gid)
+ ret = YES;
+ free(grouplist);
+ return (ret);
+}
+
+/* user_match - match a username against one token */
+
+static int
+user_match(const char *tok, const char *string,
+ struct pam_login_access_options *login_access_opts)
+{
+ size_t stringlen;
+ char *grpstr;
+ int rc;
+
/*
* If a token has the magic value "ALL" the match always succeeds.
* Otherwise, return YES if the token fully matches the username, or if
@@ -189,39 +225,18 @@ user_match(const char *tok, const char *string)
if (tok[0] == '@') { /* netgroup */
return (netgroup_match(tok + 1, (char *) 0, string));
- } else if (string_match(tok, string)) { /* ALL or exact match */
- return (YES);
- } else {
- if ((passwd = getpwnam(string)) == NULL)
- return (NO);
- errno = 0;
- if ((group = getgrnam(tok)) == NULL) {/* try group membership */
- if (errno != 0) {
- syslog(LOG_ERR, "getgrnam() failed for %s: %s", string, strerror(errno));
- } else {
- syslog(LOG_NOTICE, "group not found: %s", string);
- }
+ } else if (tok[0] == '(' && tok[(stringlen = strlen(&tok[1]))] == ')') { /* group */
+ if ((grpstr = strndup(&tok[1], stringlen - 1)) == NULL) {
+ syslog(LOG_ERR, "cannot allocate memory for %s", string);
return (NO);
}
- errno = 0;
- if ((grouplist = calloc(ngroups, sizeof(gid_t))) == NULL) {
- if (errno == ENOMEM) {
- syslog(LOG_ERR, "cannot allocate memory for grouplist: %s", string);
- }
- return (NO);
- }
- if (getgrouplist(string, passwd->pw_gid, grouplist, &ngroups) != 0) {
- syslog(LOG_ERR, "getgrouplist() failed for %s", string);
- free(grouplist);
- return (NO);
- }
- for (i = 0; i < ngroups; i++) {
- if (grouplist[i] == group->gr_gid) {
- free(grouplist);
- return (YES);
- }
- }
- free(grouplist);
+ rc = group_match(grpstr, string);
+ free(grpstr);
+ return (rc);
+ } else if (string_match(tok, string)) { /* ALL or exact match */
+ return (YES);
+ } else if (login_access_opts->defgroup == true) {/* try group membership */
+ return (group_match(tok, string));
}
return (NO);
}
@@ -229,7 +244,8 @@ user_match(const char *tok, const char *string)
/* from_match - match a host or tty against a list of tokens */
static int
-from_match(const char *tok, const char *string)
+from_match(const char *tok, const char *string,
+ struct pam_login_access_options *login_access_opts __unused)
{
int tok_len;
int str_len;
Modified: head/lib/libpam/modules/pam_login_access/pam_login_access.8
==============================================================================
--- head/lib/libpam/modules/pam_login_access/pam_login_access.8 Tue Feb 18 11:27:05 2020 (r358069)
+++ head/lib/libpam/modules/pam_login_access/pam_login_access.8 Tue Feb 18 11:27:08 2020 (r358070)
@@ -34,7 +34,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd January 24, 2002
+.Dd January 30, 2020
.Dt PAM_LOGIN_ACCESS 8
.Os
.Sh NAME
@@ -63,13 +63,46 @@ The
.Pa login.access
account management component
.Pq Fn pam_sm_acct_mgmt ,
-returns success if and only the user is allowed to log in on the
+returns success if and only the user is allowed to login on the
specified tty (in the case of a local login) or from the specified
remote host (in the case of a remote login), according to the
restrictions listed in
.Xr login.access 5 .
+.Bl -tag -width ".Cm accessfile=pathname"
+.It Cm accessfile Ns = Ns Ar pathname
+specifies a non-standard location for the
+.Pa login.access
+configuration file
+(normally located in
+.Pa /etc/login.access ) .
+.It Cm nodefgroup
+makes tokens not enclosed in parentheses only match users, requiring groups
+to be specified in parentheses.
+Without
+.Cm nodefgroup
+user and group names are intermingled, with user entries taking precedence
+over group entries.
+This is not backwards compatible with legacy
+.Pa login.access
+configuration files.
+However this mitigates confusion between users and
+groups of the same name.
+.It Cm fieldsep Ns = Ns Ar separators
+changes the field separator from the default ":".
+More than one separator
+may be specified.
+.It Cm listsep Ns = Ns Ar separators
+changes the field separator from the default space (''), tab (\\t) and
+comma (,).
+More than one separator may be specified.
+For example, listsep=;
+will replace the default with a semicolon (;).
+This option may be useful when specifying Active Directory groupnames which
+typically contain spaces.
+.El
.Sh SEE ALSO
.Xr pam 3 ,
+.Xr syslog 3 ,
.Xr login.access 5 ,
.Xr pam.conf 5
.Sh AUTHORS
Modified: head/lib/libpam/modules/pam_login_access/pam_login_access.c
==============================================================================
--- head/lib/libpam/modules/pam_login_access/pam_login_access.c Tue Feb 18 11:27:05 2020 (r358069)
+++ head/lib/libpam/modules/pam_login_access/pam_login_access.c Tue Feb 18 11:27:08 2020 (r358070)
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
#define _BSD_SOURCE
#include <sys/param.h>
+#include <sys/types.h>
#include <syslog.h>
#include <unistd.h>
@@ -51,13 +52,25 @@ __FBSDID("$FreeBSD$");
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
+#include <security/openpam.h>
#include "pam_login_access.h"
+#define OPT_ACCESSFILE "accessfile"
+#define OPT_NOAUDIT "noaudit"
+#define OPT_FIELDSEP "fieldsep"
+#define OPT_LISTSEP "listsep"
+#define OPT_NODEFGROUP "nodefgroup"
+
+#define _PATH_LOGACCESS "/etc/login.access"
+#define _FIELD_SEPARATOR ":"
+#define _LIST_SEPARATOR ", \t"
+
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
+ struct pam_login_access_options login_access_opts;
const void *rhost, *tty, *user;
char hostname[MAXHOSTNAMELEN];
int pam_err;
@@ -80,25 +93,33 @@ pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unuse
return (pam_err);
gethostname(hostname, sizeof hostname);
+ login_access_opts.defgroup = openpam_get_option(pamh, OPT_NODEFGROUP) == NULL ? true : false;
+ login_access_opts.audit = openpam_get_option(pamh, OPT_NOAUDIT) == NULL ? true : false;
+ if ((login_access_opts.accessfile = openpam_get_option(pamh, OPT_ACCESSFILE)) == NULL)
+ login_access_opts.accessfile = _PATH_LOGACCESS;
+ if ((login_access_opts.fieldsep = openpam_get_option(pamh, OPT_FIELDSEP)) == NULL)
+ login_access_opts.fieldsep = _FIELD_SEPARATOR;
+ if ((login_access_opts.listsep = openpam_get_option(pamh, OPT_LISTSEP)) == NULL)
+ login_access_opts.listsep = _LIST_SEPARATOR;
if (rhost != NULL && *(const char *)rhost != '\0') {
PAM_LOG("Checking login.access for user %s from host %s",
(const char *)user, (const char *)rhost);
- if (login_access(user, rhost) != 0)
+ if (login_access(user, rhost, &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in from %s",
(const char *)user, (const char *)rhost);
} else if (tty != NULL && *(const char *)tty != '\0') {
PAM_LOG("Checking login.access for user %s on tty %s",
(const char *)user, (const char *)tty);
- if (login_access(user, tty) != 0)
+ if (login_access(user, tty, &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in on %s",
(const char *)user, (const char *)tty);
} else {
PAM_LOG("Checking login.access for user %s",
(const char *)user);
- if (login_access(user, "***unknown***") != 0)
+ if (login_access(user, "***unknown***", &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in",
(const char *)user);
Modified: head/lib/libpam/modules/pam_login_access/pam_login_access.h
==============================================================================
--- head/lib/libpam/modules/pam_login_access/pam_login_access.h Tue Feb 18 11:27:05 2020 (r358069)
+++ head/lib/libpam/modules/pam_login_access/pam_login_access.h Tue Feb 18 11:27:08 2020 (r358070)
@@ -38,4 +38,15 @@
* $FreeBSD$
*/
-extern int login_access(const char *, const char *);
+#include <stdbool.h>
+
+struct pam_login_access_options {
+ bool defgroup;
+ bool audit;
+ const char *accessfile;
+ /* Delimiters for fields and for lists of users, ttys or hosts. */
+ const char *fieldsep; /* field separator */
+ const char *listsep; /* list-element separator */
+};
+
+extern int login_access(const char *, const char *, struct pam_login_access_options *);
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