Relevant BUGIDs:

Purpose of commit: new feature

Commit summary:
---------------

2006-12-06  Thorsten Kukuk  <kukuk@thkukuk.de>

        * modules/pam_faildelay/pam_faildelay.c: If no argument is
        given, try to read FAIL_DELAY from /etc/login.defs.
        * modules/pam_faildelay/pam_faildelay.8.xml: Document usage
        of /etc/login.defs.

1 files changed, 109 insertions, 1 deletions

diff --git a/modules/pam_faildelay/pam_faildelay.c b/modules/pam_faildelay/pam_faildelay.c
index 0fa910b7..16cb7458 100644
--- a/modules/pam_faildelay/pam_faildelay.c
+++ b/modules/pam_faildelay/pam_faildelay.c
@@ -11,10 +11,16 @@
  * auth    required        pam_faildelay.so delay=10000000
  * will set the delay on failure to 10 seconds.
  *
+ * If no delay option was given, pam_faildelay.so will use the
+ * FAIL_DELAY value of /etc/login.defs.
  *
  * Based on pam_rootok and parts of pam_unix both by Andrew Morgan
  *  <morgan@linux.kernel.org>
  *
+ * Copyright (c) 2006 Thorsten Kukuk <kukuk@thkukuk.de>
+ * - Rewrite to use extended PAM functions
+ * - Add /etc/login.defs support
+ *
  * Portions Copyright (c) 2005 Darren Tucker <dtucker at zip com au>.
  *
  * Redistribution and use in source and binary forms of, with
@@ -55,10 +61,14 @@
 
 #include "config.h"
 
+#include <errno.h>
+#include <ctype.h>
 #include <stdio.h>
+#include <limits.h>
 #include <unistd.h>
 #include <syslog.h>
 #include <string.h>
+#include <stdlib.h>
 
 
 #define PAM_SM_AUTH
@@ -67,6 +77,79 @@
 #include <security/pam_ext.h>
 
 
+#define BUF_SIZE 8192
+#define LOGIN_DEFS "/etc/login.defs"
+
+static char *
+search_key (const char *filename)
+{
+  FILE *fp;
+  char *buf = NULL;
+  size_t buflen = 0;
+  char *retval = NULL;
+
+  fp = fopen (filename, "r");
+  if (NULL == fp)
+    return NULL;
+
+  while (!feof (fp))
+    {
+      char *tmp, *cp;
+#if defined(HAVE_GETLINE)
+      ssize_t n = getline (&buf, &buflen, fp);
+#elif defined (HAVE_GETDELIM)
+      ssize_t n = getdelim (&buf, &buflen, '\n', fp);
+#else
+      ssize_t n;
+
+      if (buf == NULL)
+        {
+          buflen = BUF_SIZE;
+          buf = malloc (buflen);
+        }
+      buf[0] = '\0';
+      if (fgets (buf, buflen - 1, fp) == NULL)
+        break;
+      else if (buf != NULL)
+        n = strlen (buf);
+      else
+        n = 0;
+#endif /* HAVE_GETLINE / HAVE_GETDELIM */
+      cp = buf;
+
+      if (n < 1)
+        break;
+
+      tmp = strchr (cp, '#');  /* remove comments */
+      if (tmp)
+        *tmp = '\0';
+      while (isspace ((int)*cp))    /* remove spaces and tabs */
+        ++cp;
+      if (*cp == '\0')        /* ignore empty lines */
+        continue;
+
+      if (cp[strlen (cp) - 1] == '\n')
+        cp[strlen (cp) - 1] = '\0';
+
+      tmp = strsep (&cp, " \t=");
+      if (cp != NULL)
+        while (isspace ((int)*cp) || *cp == '=')
+          ++cp;
+
+      if (strcasecmp (tmp, "FAIL_DELAY") == 0)
+        {
+          retval = strdup (cp);
+          break;
+        }
+    }
+  fclose (fp);
+
+  free (buf);
+
+  return retval;
+}
+
+
 /* --- authentication management functions (only) --- */
 
 PAM_EXTERN
@@ -74,7 +157,7 @@ int pam_sm_authenticate(pam_handle_t *pamh, int flags UNUSED,
 			int argc, const char **argv)
 {
     int i, debug_flag = 0;
-    long int delay = 0;
+    long int delay = -1;
 
     /* step through arguments */
     for (i = 0; i < argc; i++) {
@@ -86,6 +169,31 @@ int pam_sm_authenticate(pam_handle_t *pamh, int flags UNUSED,
 	  pam_syslog (pamh, LOG_ERR, "unknown option; %s", argv[i]);
     }
 
+    if (delay == -1)
+      {
+	char *endptr;
+	char *val = search_key (LOGIN_DEFS);
+	const char *val_orig = val;
+
+	if (val == NULL)
+	  return PAM_IGNORE;
+
+	errno = 0;
+	delay = strtol (val, &endptr, 10) & 0777;
+	if (((delay == 0) && (val_orig == endptr)) ||
+	    ((delay == LONG_MIN || delay == LONG_MAX) && (errno == ERANGE)))
+	  {
+	    pam_syslog (pamh, LOG_ERR, "FAIL_DELAY=%s in %s not valid",
+			val, LOGIN_DEFS);
+	    free (val);
+	    return PAM_IGNORE;
+	  }
+
+	free (val);
+	/* delay is in seconds, convert to microseconds. */
+	delay *= 1000000;
+      }
+
     if (debug_flag)
       pam_syslog (pamh, LOG_DEBUG, "setting fail delay to %ld", delay);