Relevant BUGIDs: 667584 664290

Purpose of commit: bugfix

Commit summary:
---------------
Two bug fixes in one: don't trust getlogin() and sanely lower the
time the password databases are locked in pam_unix.

3 files changed, 76 insertions, 2 deletions

diff --git a/modules/pammodutil/Makefile b/modules/pammodutil/Makefile
index a97388ef..b4868528 100644
--- a/modules/pammodutil/Makefile
+++ b/modules/pammodutil/Makefile
@@ -18,7 +18,8 @@ CFLAGS += $(PIC) $(STATIC) $(MOREFLAGS) \
   -DLIBPAM_VERSION_MINOR=$(MINOR_REL)
 
 # all the object files we care about
-LIBOBJECTS = modutil_cleanup.o modutil_getpwnam.o modutil_getpwuid.o
+LIBOBJECTS = modutil_cleanup.o modutil_getpwnam.o modutil_getpwuid.o \
+	modutil_getlogin.o
 
 # static library name
 LIBSTATIC = $(LIBNAME).a
diff --git a/modules/pammodutil/include/security/_pam_modutil.h b/modules/pammodutil/include/security/_pam_modutil.h
index af8a7ae1..5e063651 100644
--- a/modules/pammodutil/include/security/_pam_modutil.h
+++ b/modules/pammodutil/include/security/_pam_modutil.h
@@ -15,7 +15,7 @@
  * On systems that simply can't support thread safe programming, these
  * functions don't support it either - sorry.
  *
- * Copyright (c) 2001 Andrew Morgan <morgan@kernel.org>
+ * Copyright (c) 2001-2002 Andrew Morgan <morgan@kernel.org>
  */
 
 #include <pwd.h>
@@ -30,4 +30,6 @@ extern struct passwd *_pammodutil_getpwuid(pam_handle_t *pamh,
 extern void _pammodutil_cleanup(pam_handle_t *pamh, void *data,
 				int error_status);
 
+extern const char *_pammodutil_getlogin(pam_handle_t *pamh);
+
 #endif /* _PAM_MODUTIL_H */
diff --git a/modules/pammodutil/modutil_getlogin.c b/modules/pammodutil/modutil_getlogin.c
new file mode 100644
index 00000000..b624def1
--- /dev/null
+++ b/modules/pammodutil/modutil_getlogin.c
@@ -0,0 +1,71 @@
+/*
+ * $Id$
+ *
+ * A central point for invoking getlogin(). Hopefully, this is a
+ * little harder to spoof than all the other versions that are out
+ * there.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <utmp.h>
+
+#include "pammodutil.h"
+
+#define _PAMMODUTIL_GETLOGIN "_pammodutil_getlogin"
+
+const char *_pammodutil_getlogin(pam_handle_t *pamh)
+{
+    int status;
+    const char *logname, *curr_tty;
+    char *curr_user;
+    struct utmp *ut, line;
+
+    status = pam_get_data(pamh, _PAMMODUTIL_GETLOGIN,
+			  (const void **) &logname);
+    if (status == PAM_SUCCESS) {
+	return logname;
+    }
+
+    status = pam_get_item(pamh, PAM_TTY, (const void **) &curr_tty);
+    if ((status != PAM_SUCCESS) || (curr_tty == NULL)) {
+	curr_tty = ttyname(0);
+    }
+
+    if ((curr_tty == NULL) || memcmp(curr_tty, "/dev/", 5)) {
+	return NULL;
+    }
+
+    curr_tty += 5;  /* strlen("/dev/") */
+    logname = NULL;
+
+    setutent();
+    strncpy(line.ut_line, curr_tty, sizeof(line.ut_line));
+
+    if ((ut = getutline(&line)) == NULL) {
+	goto clean_up_and_go_home;
+    }
+
+    curr_user = calloc(sizeof(line.ut_user)+1, 1);
+    if (curr_user == NULL) {
+	goto clean_up_and_go_home;
+    }
+
+    strncpy(curr_user, ut->ut_user, sizeof(ut->ut_user));
+    curr_user[sizeof(line.ut_user)] = '\0';
+
+    status = pam_set_data(pamh, _PAMMODUTIL_GETLOGIN, logname,
+			  _pammodutil_cleanup);
+    if (status != PAM_SUCCESS) {
+	free(curr_user);
+	goto clean_up_and_go_home;
+    }
+
+    logname = curr_user;
+
+clean_up_and_go_home:
+
+    endutent();
+
+    return logname;
+}