Goal: Do not hardcode pam_fail_delay and let pam_unix do its
      job to set a delay...or not

Fixes: #87648

Status wrt upstream: Forwarded but not applied yet

Note: If removed, FAIL_DELAY must be re-added to /etc/login.defs

Index: shadow-4.1.0/src/login.c
===================================================================
--- shadow-4.1.0.orig/src/login.c
+++ shadow-4.1.0/src/login.c
@@ -331,7 +331,6 @@
 #if defined(HAVE_STRFTIME) && !defined(USE_PAM)
 	char ptime[80];
 #endif
-	int delay;
 	int retries;
 	bool failed;
 	bool subroot = false;
@@ -354,6 +353,7 @@
 	char *pam_user;
 	char **ptr_pam_user = &pam_user;
 #else
+	int delay;
 	struct spwd *spwd = NULL;
 #endif
 	/*
@@ -578,7 +578,6 @@
 	}
 
 	environ = newenvp;	/* make new environment active */
-	delay = getdef_num ("FAIL_DELAY", 1);
 	retries = getdef_num ("LOGIN_RETRIES", RETRIES);
 
 #ifdef USE_PAM
@@ -594,17 +593,12 @@
 
 	/*
 	 * hostname & tty are either set to NULL or their correct values,
-	 * depending on how much we know. We also set PAM's fail delay to
-	 * ours.
+	 * depending on how much we know.
 	 */
 	retcode = pam_set_item (pamh, PAM_RHOST, hostname);
 	PAM_FAIL_CHECK;
 	retcode = pam_set_item (pamh, PAM_TTY, tty);
 	PAM_FAIL_CHECK;
-#ifdef HAS_PAM_FAIL_DELAY
-	retcode = pam_fail_delay (pamh, 1000000 * delay);
-	PAM_FAIL_CHECK;
-#endif
 	/* if fflg, then the user has already been authenticated */
 	if (!fflg || (getuid () != 0)) {
 		int failcount = 0;
@@ -645,12 +639,6 @@
 			failed = false;
 
 			failcount++;
-#ifdef HAS_PAM_FAIL_DELAY
-			if (delay > 0) {
-				retcode = pam_fail_delay(pamh, 1000000*delay);
-				PAM_FAIL_CHECK;
-			}
-#endif
 
 			retcode = pam_authenticate (pamh, 0);
 
@@ -956,14 +948,17 @@
 			pw_auth ("!", username, reason, (char *) 0);
 		}
 
+#ifndef USE_PAM
 		/*
 		 * Wait a while (a la SVR4 /usr/bin/login) before attempting
 		 * to login the user again. If the earlier alarm occurs
 		 * before the sleep() below completes, login will exit.
 		 */
+		delay = getdef_num ("FAIL_DELAY", 1);
 		if (delay > 0) {
 			sleep (delay);
		}
+#endif
 
 		puts (_("Login incorrect"));
 
Index: shadow-4.1.0/lib/getdef.c
===================================================================
--- shadow-4.1.0.orig/lib/getdef.c
+++ shadow-4.1.0/lib/getdef.c
@@ -56,7 +56,6 @@
 	{"ENV_PATH", NULL},
 	{"ENV_SUPATH", NULL},
 	{"ERASECHAR", NULL},
-	{"FAIL_DELAY", NULL},
 	{"FAILLOG_ENAB", NULL},
 	{"FAKE_SHELL", NULL},
 	{"FTMP_FILE", NULL},
@@ -94,6 +93,7 @@
 	{"ENV_HZ", NULL},
 	{"ENVIRON_FILE", NULL},
 	{"ENV_TZ", NULL},
+	{"FAIL_DELAY", NULL},
 	{"ISSUE_FILE", NULL},
 	{"LASTLOG_ENAB", NULL},
 	{"LOGIN_STRING", NULL},
