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
This commit is contained in:
cy
parent
70e579827c
commit
4bbdfe4e6e
@ -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
|
||||
|
||||
@ -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);
|
||||
}
|
||||
@ -170,16 +173,49 @@ netgroup_match(const char *group, const char *machine, const char *user)
|
||||
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.
|
||||
@ -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 (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);
|
||||
}
|
||||
rc = group_match(grpstr, string);
|
||||
free(grpstr);
|
||||
return (rc);
|
||||
} 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);
|
||||
}
|
||||
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);
|
||||
} 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;
|
||||
|
||||
@ -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
|
||||
|
||||
@ -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 __unused,
|
||||
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);
|
||||
|
||||
@ -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 *);
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user