login: optional support for PAM
diff --git a/Makefile.flags b/Makefile.flags
index d8817be..c64a5c8 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -60,18 +60,20 @@
endif
BBOX_LIB_LIST = m crypt
+
+ifeq ($(CONFIG_PAM),y)
+BBOX_LIB_LIST += pam pam_misc
+endif
+
ifeq ($(CONFIG_SELINUX),y)
-#LDLIBS += -lselinux -lsepol
BBOX_LIB_LIST += selinux sepol
endif
ifeq ($(CONFIG_EFENCE),y)
-#LDLIBS += -lefence
BBOX_LIB_LIST += efence
endif
ifeq ($(CONFIG_DMALLOC),y)
-#LDLIBS += -ldmalloc
BBOX_LIB_LIST += dmalloc
endif
diff --git a/loginutils/Config.in b/loginutils/Config.in
index 63ae9b4..6f2702e 100644
--- a/loginutils/Config.in
+++ b/loginutils/Config.in
@@ -128,6 +128,13 @@
Note that Busybox binary must be setuid root for this applet to
work properly.
+config PAM
+ bool "Support for PAM (Pluggable Authentication Modules)"
+ default n
+ depends on LOGIN
+ help
+ Use PAM in login(1) instead of direct access to password database.
+
config LOGIN_SCRIPTS
bool "Support for login scripts"
depends on LOGIN
diff --git a/loginutils/login.c b/loginutils/login.c
index 7b60fd0..b633a7f 100644
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -14,6 +14,15 @@
#include <selinux/flask.h> /* for security class definitions */
#endif
+#if ENABLE_PAM
+#include <pam/pam_appl.h>
+#include <pam/pam_misc.h>
+static const struct pam_conv conv = {
+ misc_conv,
+ NULL
+};
+#endif
+
enum {
TIMEOUT = 60,
EMPTY_USERNAME_COUNT = 10,
@@ -125,7 +134,7 @@
static ALWAYS_INLINE void die_if_nologin_and_non_root(int amroot) {}
#endif
-#if ENABLE_FEATURE_SECURETTY
+#if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM
static int check_securetty(void)
{
FILE *fp;
@@ -214,7 +223,7 @@
LOGIN_OPT_h = (1<<1),
LOGIN_OPT_p = (1<<2),
};
- char fromhost[512];
+ char *fromhost;
char username[USERNAME_SIZE];
const char *tmp;
int amroot;
@@ -226,6 +235,9 @@
char full_tty[TTYNAME_SIZE];
USE_SELINUX(security_context_t user_sid = NULL;)
USE_FEATURE_UTMP(struct utmp utent;)
+ USE_PAM(pam_handle_t *pamh;)
+ USE_PAM(int pamret;)
+ USE_PAM(const char *failed_msg;)
short_tty = full_tty;
username[0] = '\0';
@@ -265,13 +277,12 @@
USE_FEATURE_UTMP(
safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
)
- snprintf(fromhost, sizeof(fromhost)-1, " on '%.100s' from "
- "'%.200s'", short_tty, opt_host);
+ fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host);
} else
- snprintf(fromhost, sizeof(fromhost)-1, " on '%.100s'", short_tty);
+ fromhost = xasprintf(" on '%s'", short_tty);
- // Was breaking "login <username>" from shell command line:
- // bb_setpgrp();
+ /* Was breaking "login <username>" from shell command line: */
+ /*bb_setpgrp();*/
openlog(applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
@@ -279,6 +290,46 @@
if (!username[0])
get_username_or_die(username, sizeof(username));
+#if ENABLE_PAM
+ pamret = pam_start("login", username, &conv, &pamh);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "pam_start";
+ goto pam_auth_failed;
+ }
+ /* set TTY (so things like securetty work) */
+ pamret = pam_set_item(pamh, PAM_TTY, short_tty);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "pam_set_item(TTY)";
+ goto pam_auth_failed;
+ }
+ pamret = pam_authenticate(pamh, 0);
+ if (pamret == PAM_SUCCESS) {
+ char *pamuser;
+ /* check that the account is healthy. */
+ pamret = pam_acct_mgmt(pamh, 0);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "account setup";
+ goto pam_auth_failed;
+ }
+ /* read user back */
+ /* gcc: "dereferencing type-punned pointer breaks aliasing rules..."
+ * thus we use double cast */
+ if (pam_get_item(pamh, PAM_USER, (const void **)(void*)&pamuser) != PAM_SUCCESS) {
+ failed_msg = "pam_get_item(USER)";
+ goto pam_auth_failed;
+ }
+ safe_strncpy(username, pamuser, sizeof(username));
+ }
+ /* If we get here, the user was authenticated, and is
+ * granted access. */
+ pw = getpwnam(username);
+ if (pw)
+ break;
+ goto auth_failed;
+ pam_auth_failed:
+ bb_error_msg("%s failed: %s", failed_msg, pam_strerror(pamh, pamret));
+ safe_strncpy(username, "UNKNOWN", sizeof(username));
+#else /* not PAM */
pw = getpwnam(username);
if (!pw) {
strcpy(username, "UNKNOWN");
@@ -301,6 +352,7 @@
/* authorization takes place here */
if (correct_password(pw))
break;
+#endif /* ENABLE_PAM */
auth_failed:
opt &= ~LOGIN_OPT_f;
bb_do_delay(FAIL_DELAY);