From 78c00f172ea4d4fd244db7f91ca7eb101efe2038 Mon Sep 17 00:00:00 2001
From: sebastienblavier <72022031+sebastienblavier@users.noreply.github.com>
Date: Mon, 18 Jan 2021 22:41:08 +0100
Subject: Add tls_crlcheck to check Certificate Revocation List

This option is passed to the LDAP library if it is supported.

Closes https://github.com/arthurdejong/nss-pam-ldapd/pull/41
---
 man/nslcd.conf.5.xml | 13 +++++++++++++
 nslcd.conf           |  3 +++
 nslcd/cfg.c          | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/man/nslcd.conf.5.xml b/man/nslcd.conf.5.xml
index 4e81645..8310718 100644
--- a/man/nslcd.conf.5.xml
+++ b/man/nslcd.conf.5.xml
@@ -656,6 +656,19 @@
      </listitem>
     </varlistentry>
 
+    <varlistentry id="tls_crlcheck"> <!-- since 0.9.12 -->
+     <term><option>tls_crlcheck</option> <replaceable>none|peer|all</replaceable></term>
+     <listitem>
+      <para>
+       Specifies if the Certificate Revocation List (CRL) of the CA should
+       be used to verify if the server certificates have not been revoked.
+       The meaning of the values is described in the
+       <citerefentry><refentrytitle>ldap.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+       manual page.
+      </para>
+     </listitem>
+    </varlistentry>
+
    </variablelist>
   </refsect2>
 
diff --git a/nslcd.conf b/nslcd.conf
index 7b1bcf3..d45b57c 100644
--- a/nslcd.conf
+++ b/nslcd.conf
@@ -66,6 +66,9 @@ base dc=example,dc=com
 #tls_cacertdir /etc/ssl/certs
 #tls_cacertfile /etc/ssl/ca.cert
 
+# Certificate Revocation List (CRL), requires TLS_CACERTDIR parameter to be set
+#tls_crlcheck all
+
 # Seed the PRNG if /dev/urandom is not provided
 #tls_randfile /var/run/egd-pool
 
diff --git a/nslcd/cfg.c b/nslcd/cfg.c
index 404ffda..b00546c 100644
--- a/nslcd/cfg.c
+++ b/nslcd/cfg.c
@@ -885,6 +885,45 @@ static const char *print_tls_reqcert(int value)
     default:                    return "???";
   }
 }
+
+#ifdef LDAP_OPT_X_TLS_CRLCHECK
+static void handle_tls_crlcheck(const char *filename, int lnr,
+                               const char *keyword, char *line)
+{
+  char token[16];
+  int value, rc;
+  /* get token */
+  check_argumentcount(filename, lnr, keyword,
+                      get_token(&line, token, sizeof(token)) != NULL);
+  get_eol(filename, lnr, keyword, &line);
+  /* check if it is a valid value for tls_crlcheck option */
+  if (strcasecmp(token, "none") == 0)
+    value = LDAP_OPT_X_TLS_CRL_NONE;
+  else if (strcasecmp(token, "peer") == 0)
+    value = LDAP_OPT_X_TLS_CRL_PEER;
+  else if (strcasecmp(token, "all") == 0)
+    value = LDAP_OPT_X_TLS_CRL_ALL;
+  else
+  {
+    log_log(LOG_ERR, "%s:%d: %s: invalid argument: '%s'",
+            filename, lnr, keyword, token);
+    exit(EXIT_FAILURE);
+  }
+  log_log(LOG_DEBUG, "ldap_set_option(LDAP_OPT_X_TLS_CRLCHECK,%s)", token);
+  LDAP_SET_OPTION(NULL, LDAP_OPT_X_TLS_CRLCHECK, &value);
+}
+
+static const char *print_tls_crlcheck(int value)
+{
+  switch (value)
+  {
+    case LDAP_OPT_X_TLS_CRL_NONE:  return "none";
+    case LDAP_OPT_X_TLS_CRL_PEER:  return "peer";
+    case LDAP_OPT_X_TLS_CRL_ALL:   return "all";
+    default:                       return "???";
+  }
+}
+#endif /* LDAP_OPT_X_TLS_CRLCHECK */
 #endif /* LDAP_OPT_X_TLS */
 
 /* this function modifies the line argument passed */
@@ -1560,6 +1599,12 @@ static void cfg_read(const char *filename, struct ldap_config *cfg)
       LDAP_SET_OPTION(NULL, LDAP_OPT_X_TLS_KEYFILE, value);
       free(value);
     }
+#ifdef LDAP_OPT_X_TLS_CRLCHECK
+    else if (strcasecmp(keyword, "tls_crlcheck") == 0)
+    {
+      handle_tls_crlcheck(filename, lnr, keyword, line);
+    }
+#endif /* LDAP_OPT_X_TLS_CRLCHECK */
 #endif /* LDAP_OPT_X_TLS */
     /* other options */
     else if (strcasecmp(keyword, "pagesize") == 0)
@@ -1851,6 +1896,13 @@ static void cfg_dump(void)
   LOG_LDAP_OPT_STRING("tls_ciphers", LDAP_OPT_X_TLS_CIPHER_SUITE);
   LOG_LDAP_OPT_STRING("tls_cert", LDAP_OPT_X_TLS_CERTFILE);
   LOG_LDAP_OPT_STRING("tls_key", LDAP_OPT_X_TLS_KEYFILE);
+#ifdef LDAP_OPT_X_TLS_CRLCHECK
+  rc = ldap_get_option(NULL, LDAP_OPT_X_TLS_CRLCHECK, &i);
+  if (rc != LDAP_SUCCESS)
+    log_log(LOG_DEBUG, "CFG: # tls_crlcheck ERROR: %s", ldap_err2string(rc));
+  else
+    log_log(LOG_DEBUG, "CFG: tls_crlcheck %s", print_tls_crlcheck(i));
+#endif /* LDAP_OPT_X_TLS_CRLCHECK */
 #endif /* LDAP_OPT_X_TLS */
   log_log(LOG_DEBUG, "CFG: pagesize %d", nslcd_cfg->pagesize);
   if (nslcd_cfg->nss_initgroups_ignoreusers != NULL)
-- 
cgit v1.2.3