1 files changed, 71 insertions, 0 deletions
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;
+}