pause for some time on wrong password

us.c

@@ -61,6 +61,7 @@
 #define FLAG_NOLOG 0x4
 #define SESSION_FILE_DIR "/var/run"
 #define SESSION_TIMEOUT (60*5)
+#define FAIL_PAUSE 3
 
 struct env_elem {
 	char *name;
@@ -620,6 +621,7 @@ static int authenticate(uid_t uid, int ask, int persist)
 	/* Remove password from memory, just to be sure */
 	memset(pass, 0, PASS_MAX);
 	if (strncmp(hash, enc, PASS_MAX)) {
+		sleep(FAIL_PAUSE);
 		printf("Authentication failure\n");
 		setuid(uid);
 		return -1;