Imported Upstream version 2.3_rc1

1 files changed, 1265 insertions, 0 deletions

diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c
new file mode 100644
index 0000000..cac46e9
--- /dev/null
+++ b/src/openvpn/ssl_verify.c
@@ -0,0 +1,1265 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single TCP/UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ *  Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/**
+ * @file Control Channel Verification Module
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_CRYPTO) && defined(ENABLE_SSL)
+
+#include "misc.h"
+#include "manage.h"
+#include "ssl_verify.h"
+#include "ssl_verify_backend.h"
+
+#ifdef ENABLE_CRYPTO_OPENSSL
+#include "ssl_verify_openssl.h"
+#endif
+
+/** Maximum length of common name */
+#define TLS_USERNAME_LEN 64
+
+/** Legal characters in an X509 name with --compat-names */
+#define X509_NAME_CHAR_CLASS   (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_SLASH|CC_COLON|CC_EQUAL)
+
+/** Legal characters in a common name with --compat-names */
+#define COMMON_NAME_CHAR_CLASS (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_SLASH)
+
+static void
+string_mod_remap_name (char *str, const unsigned int restrictive_flags)
+{
+  if (compat_flag (COMPAT_FLAG_QUERY | COMPAT_NAMES)
+      && !compat_flag (COMPAT_FLAG_QUERY | COMPAT_NO_NAME_REMAPPING))
+    string_mod (str, restrictive_flags, 0, '_');
+  else
+    string_mod (str, CC_PRINT, CC_CRLF, '_');
+}
+
+/*
+ * Export the untrusted IP address and port to the environment
+ */
+static void
+setenv_untrusted (struct tls_session *session)
+{
+  setenv_link_socket_actual (session->opt->es, "untrusted", &session->untrusted_addr, SA_IP_PORT);
+}
+
+/*
+ * Remove authenticated state from all sessions in the given tunnel
+ */
+static void
+tls_deauthenticate (struct tls_multi *multi)
+{
+  if (multi)
+    {
+      int i, j;
+      for (i = 0; i < TM_SIZE; ++i)
+	for (j = 0; j < KS_SIZE; ++j)
+	  multi->session[i].key[j].authenticated = false;
+    }
+}
+
+/*
+ * Set the given session's common_name
+ */
+static void
+set_common_name (struct tls_session *session, const char *common_name)
+{
+  if (session->common_name)
+    {
+      free (session->common_name);
+      session->common_name = NULL;
+#ifdef ENABLE_PF
+      session->common_name_hashval = 0;
+#endif
+    }
+  if (common_name)
+    {
+      /* FIXME: Last alloc will never be freed */
+      session->common_name = string_alloc (common_name, NULL);
+#ifdef ENABLE_PF
+      {
+	const uint32_t len = (uint32_t) strlen (common_name);
+	if (len)
+	  session->common_name_hashval = hash_func ((const uint8_t*)common_name, len+1, 0);
+	else
+	  session->common_name_hashval = 0;
+      }
+#endif
+    }
+}
+
+/*
+ * Retrieve the common name for the given tunnel's active session. If the
+ * common name is NULL or empty, return NULL if null is true, or "UNDEF" if
+ * null is false.
+ */
+const char *
+tls_common_name (const struct tls_multi *multi, const bool null)
+{
+  const char *ret = NULL;
+  if (multi)
+    ret = multi->session[TM_ACTIVE].common_name;
+  if (ret && strlen (ret))
+    return ret;
+  else if (null)
+    return NULL;
+  else
+    return "UNDEF";
+}
+
+/*
+ * Lock the common name for the given tunnel.
+ */
+void
+tls_lock_common_name (struct tls_multi *multi)
+{
+  const char *cn = multi->session[TM_ACTIVE].common_name;
+  if (cn && !multi->locked_cn)
+    multi->locked_cn = string_alloc (cn, NULL);
+}
+
+/*
+ * Lock the username for the given tunnel
+ */
+static bool
+tls_lock_username (struct tls_multi *multi, const char *username)
+{
+  if (multi->locked_username)
+    {
+      if (!username || strcmp (username, multi->locked_username))
+	{
+	  msg (D_TLS_ERRORS, "TLS Auth Error: username attempted to change from '%s' to '%s' -- tunnel disabled",
+	       multi->locked_username,
+	       np(username));
+
+	  /* disable the tunnel */
+	  tls_deauthenticate (multi);
+	  return false;
+	}
+    }
+  else
+    {
+      if (username)
+	multi->locked_username = string_alloc (username, NULL);
+    }
+  return true;
+}
+
+const char *
+tls_username (const struct tls_multi *multi, const bool null)
+{
+  const char *ret = NULL;
+  if (multi)
+    ret = multi->locked_username;
+  if (ret && strlen (ret))
+    return ret;
+  else if (null)
+    return NULL;
+  else
+    return "UNDEF";
+}
+
+void
+cert_hash_remember (struct tls_session *session, const int error_depth, const unsigned char *sha1_hash)
+{
+  if (error_depth >= 0 && error_depth < MAX_CERT_DEPTH)
+    {
+      if (!session->cert_hash_set)
+	ALLOC_OBJ_CLEAR (session->cert_hash_set, struct cert_hash_set);
+      if (!session->cert_hash_set->ch[error_depth])
+	ALLOC_OBJ (session->cert_hash_set->ch[error_depth], struct cert_hash);
+      {
+	struct cert_hash *ch = session->cert_hash_set->ch[error_depth];
+	memcpy (ch->sha1_hash, sha1_hash, SHA_DIGEST_LENGTH);
+      }
+    }
+}
+
+#if 0
+static void
+cert_hash_print (const struct cert_hash_set *chs, int msglevel)
+{
+  struct gc_arena gc = gc_new ();
+  msg (msglevel, "CERT_HASH");
+  if (chs)
+    {
+      int i;
+      for (i = 0; i < MAX_CERT_DEPTH; ++i)
+	{
+	  const struct cert_hash *ch = chs->ch[i];
+	  if (ch)
+	    msg (msglevel, "%d:%s", i, format_hex(ch->sha1_hash, SHA_DIGEST_LENGTH, 0, &gc));
+	}
+    }
+  gc_free (&gc);
+}
+#endif
+
+void
+cert_hash_free (struct cert_hash_set *chs)
+{
+  if (chs)
+    {
+      int i;
+      for (i = 0; i < MAX_CERT_DEPTH; ++i)
+	free (chs->ch[i]);
+      free (chs);
+    }
+}
+
+static bool
+cert_hash_compare (const struct cert_hash_set *chs1, const struct cert_hash_set *chs2)
+{
+  if (chs1 && chs2)
+    {
+      int i;
+      for (i = 0; i < MAX_CERT_DEPTH; ++i)
+	{
+	  const struct cert_hash *ch1 = chs1->ch[i];
+	  const struct cert_hash *ch2 = chs2->ch[i];
+
+	  if (!ch1 && !ch2)
+	    continue;
+	  else if (ch1 && ch2 && !memcmp (ch1->sha1_hash, ch2->sha1_hash, SHA_DIGEST_LENGTH))
+	    continue;
+	  else
+	    return false;
+	}
+      return true;
+    }
+  else if (!chs1 && !chs2)
+    return true;
+  else
+    return false;
+}
+
+static struct cert_hash_set *
+cert_hash_copy (const struct cert_hash_set *chs)
+{
+  struct cert_hash_set *dest = NULL;
+  if (chs)
+    {
+      int i;
+      ALLOC_OBJ_CLEAR (dest, struct cert_hash_set);
+      for (i = 0; i < MAX_CERT_DEPTH; ++i)
+	{
+	  const struct cert_hash *ch = chs->ch[i];
+	  if (ch)
+	    {
+	      ALLOC_OBJ (dest->ch[i], struct cert_hash);
+	      memcpy (dest->ch[i]->sha1_hash, ch->sha1_hash, SHA_DIGEST_LENGTH);
+	    }
+	}
+    }
+  return dest;
+}
+void
+tls_lock_cert_hash_set (struct tls_multi *multi)
+{
+  const struct cert_hash_set *chs = multi->session[TM_ACTIVE].cert_hash_set;
+  if (chs && !multi->locked_cert_hash_set)
+    multi->locked_cert_hash_set = cert_hash_copy (chs);
+}
+
+/*
+ * Returns the string associated with the given certificate type.
+ */
+static const char *
+print_nsCertType (int type)
+{
+  switch (type)
+    {
+    case NS_CERT_CHECK_SERVER:
+      return "SERVER";
+    case NS_CERT_CHECK_CLIENT:
+      return "CLIENT";
+    default:
+      return "?";
+    }
+}
+
+/*
+ * Verify the peer's certificate fields.
+ *
+ * @param opt the tls options to verify against
+ * @param peer_cert the peer's certificate
+ * @param subject the peer's extracted subject name
+ * @param subject the peer's extracted common name
+ */
+static result_t
+verify_peer_cert(const struct tls_options *opt, openvpn_x509_cert_t *peer_cert,
+    const char *subject, const char *common_name)
+{
+  /* verify certificate nsCertType */
+  if (opt->ns_cert_type != NS_CERT_CHECK_NONE)
+    {
+      if (SUCCESS == x509_verify_ns_cert_type (peer_cert, opt->ns_cert_type))
+	{
+	  msg (D_HANDSHAKE, "VERIFY OK: nsCertType=%s",
+	       print_nsCertType (opt->ns_cert_type));
+	}
+      else
+	{
+	  msg (D_HANDSHAKE, "VERIFY nsCertType ERROR: %s, require nsCertType=%s",
+	       subject, print_nsCertType (opt->ns_cert_type));
+	  return FAILURE;		/* Reject connection */
+	}
+    }
+
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L || ENABLE_CRYPTO_POLARSSL
+
+  /* verify certificate ku */
+  if (opt->remote_cert_ku[0] != 0)
+    {
+      if (SUCCESS == x509_verify_cert_ku (peer_cert, opt->remote_cert_ku, MAX_PARMS))
+	{
+	  msg (D_HANDSHAKE, "VERIFY KU OK");
+	}
+        else
+        {
+	  msg (D_HANDSHAKE, "VERIFY KU ERROR");
+          return FAILURE;		/* Reject connection */
+	}
+    }
+
+  /* verify certificate eku */
+  if (opt->remote_cert_eku != NULL)
+    {
+      if (SUCCESS == x509_verify_cert_eku (peer_cert, opt->remote_cert_eku))
+        {
+	  msg (D_HANDSHAKE, "VERIFY EKU OK");
+	}
+      else
+	{
+	  msg (D_HANDSHAKE, "VERIFY EKU ERROR");
+          return FAILURE;		/* Reject connection */
+	}
+    }
+
+#endif /* OPENSSL_VERSION_NUMBER */
+
+  /* verify X509 name or common name against --tls-remote */
+  if (opt->verify_x509name && strlen (opt->verify_x509name) > 0)
+    {
+      if (strcmp (opt->verify_x509name, subject) == 0
+	  || strncmp (opt->verify_x509name, common_name, strlen (opt->verify_x509name)) == 0)
+	msg (D_HANDSHAKE, "VERIFY X509NAME OK: %s", subject);
+      else
+	{
+	  msg (D_HANDSHAKE, "VERIFY X509NAME ERROR: %s, must be %s",
+	       subject, opt->verify_x509name);
+	  return FAILURE;		/* Reject connection */
+	}
+    }
+
+  return SUCCESS;
+}
+
+/*
+ * Export the subject, common_name, and raw certificate fields to the
+ * environment for later verification by scripts and plugins.
+ */
+static void
+verify_cert_set_env(struct env_set *es, openvpn_x509_cert_t *peer_cert, int cert_depth,
+    const char *subject, const char *common_name
+#ifdef ENABLE_X509_TRACK
+    , const struct x509_track *x509_track
+#endif
+    )
+{
+  char envname[64];
+  char *serial = NULL;
+  struct gc_arena gc = gc_new ();
+
+  /* Save X509 fields in environment */
+#ifdef ENABLE_X509_TRACK
+  if (x509_track)
+    x509_setenv_track (x509_track, es, cert_depth, peer_cert);
+  else
+#endif
+    x509_setenv (es, cert_depth, peer_cert);
+
+  /* export subject name string as environmental variable */
+  openvpn_snprintf (envname, sizeof(envname), "tls_id_%d", cert_depth);
+  setenv_str (es, envname, subject);
+
+#if 0
+  /* export common name string as environmental variable */
+  openvpn_snprintf (envname, sizeof(envname), "tls_common_name_%d", cert_depth);
+  setenv_str (es, envname, common_name);
+#endif
+
+#ifdef ENABLE_EUREPHIA
+  /* export X509 cert SHA1 fingerprint */
+  {
+    unsigned char *sha1_hash = x509_get_sha1_hash(peer_cert, &gc);
+
+    openvpn_snprintf (envname, sizeof(envname), "tls_digest_%d", cert_depth);
+    setenv_str (es, envname, format_hex_ex(sha1_hash, SHA_DIGEST_LENGTH, 0, 1,
+					  ":", &gc));
+  }
+#endif
+
+  /* export serial number as environmental variable */
+  serial = x509_get_serial(peer_cert, &gc);
+  openvpn_snprintf (envname, sizeof(envname), "tls_serial_%d", cert_depth);
+  setenv_str (es, envname, serial);
+
+  gc_free(&gc);
+}
+
+/*
+ * call --tls-verify plug-in(s)
+ */
+static result_t
+verify_cert_call_plugin(const struct plugin_list *plugins, struct env_set *es,
+    int cert_depth, openvpn_x509_cert_t *cert, char *subject)
+{
+  if (plugin_defined (plugins, OPENVPN_PLUGIN_TLS_VERIFY))
+    {
+      int ret;
+      struct argv argv = argv_new ();
+
+      argv_printf (&argv, "%d %s", cert_depth, subject);
+
+      ret = plugin_call_ssl (plugins, OPENVPN_PLUGIN_TLS_VERIFY, &argv, NULL, es, cert_depth, cert);
+
+      argv_reset (&argv);
+
+      if (ret == OPENVPN_PLUGIN_FUNC_SUCCESS)
+	{
+	  msg (D_HANDSHAKE, "VERIFY PLUGIN OK: depth=%d, %s",
+	      cert_depth, subject);
+	}
+      else
+	{
+	  msg (D_HANDSHAKE, "VERIFY PLUGIN ERROR: depth=%d, %s",
+	      cert_depth, subject);
+	  return FAILURE;		/* Reject connection */
+	}
+    }
+  return SUCCESS;
+}
+
+static const char *
+verify_cert_export_cert(openvpn_x509_cert_t *peercert, const char *tmp_dir, struct gc_arena *gc)
+{
+  FILE *peercert_file;
+  const char *peercert_filename="";
+
+  if(!tmp_dir)
+      return NULL;
+
+  /* create tmp file to store peer cert */
+  peercert_filename = create_temp_file (tmp_dir, "pcf", gc);
+
+  /* write peer-cert in tmp-file */
+  peercert_file = fopen(peercert_filename, "w+");
+  if(!peercert_file)
+    {
+      msg (M_ERR, "Failed to open temporary file : %s", peercert_filename);
+      return NULL;
+    }
+
+  if (SUCCESS != x509_write_pem(peercert_file, peercert))
+      msg (M_ERR, "Error writing PEM file containing certificate");
+
+  fclose(peercert_file);
+  return peercert_filename;
+}
+
+
+/*
+ * run --tls-verify script
+ */
+static result_t
+verify_cert_call_command(const char *verify_command, struct env_set *es,
+    int cert_depth, openvpn_x509_cert_t *cert, char *subject, const char *verify_export_cert)
+{
+  const char *tmp_file = NULL;
+  int ret;
+  struct gc_arena gc = gc_new();
+  struct argv argv = argv_new ();
+
+  setenv_str (es, "script_type", "tls-verify");
+
+  if (verify_export_cert)
+    {
+      if ((tmp_file=verify_cert_export_cert(cert, verify_export_cert, &gc)))
+       {
+         setenv_str(es, "peer_cert", tmp_file);
+       }
+    }
+
+  argv_printf (&argv, "%sc %d %s", verify_command, cert_depth, subject);
+
+  argv_msg_prefix (D_TLS_DEBUG, &argv, "TLS: executing verify command");
+  ret = openvpn_run_script (&argv, es, 0, "--tls-verify script");
+
+  if (verify_export_cert)
+    {
+       if (tmp_file)
+          platform_unlink(tmp_file);
+    }
+
+  gc_free(&gc);
+  argv_reset (&argv);
+
+  if (ret)
+    {
+      msg (D_HANDSHAKE, "VERIFY SCRIPT OK: depth=%d, %s",
+	   cert_depth, subject);
+      return SUCCESS;
+    }
+
+  msg (D_HANDSHAKE, "VERIFY SCRIPT ERROR: depth=%d, %s",
+       cert_depth, subject);
+  return FAILURE;		/* Reject connection */
+}
+
+/*
+ * check peer cert against CRL directory
+ */
+static result_t
+verify_check_crl_dir(const char *crl_dir, openvpn_x509_cert_t *cert)
+{
+  result_t ret = FAILURE;
+  char fn[256];
+  int fd = -1;
+  struct gc_arena gc = gc_new();
+
+  char *serial = x509_get_serial(cert, &gc);
+
+  if (!openvpn_snprintf(fn, sizeof(fn), "%s%c%s", crl_dir, OS_SPECIFIC_DIRSEP, serial))
+    {
+      msg (D_HANDSHAKE, "VERIFY CRL: filename overflow");
+      goto cleanup;
+    }
+  fd = platform_open (fn, O_RDONLY, 0);
+  if (fd >= 0)
+    {
+      msg (D_HANDSHAKE, "VERIFY CRL: certificate serial number %s is revoked", serial);
+      goto cleanup;
+    }
+
+  ret = SUCCESS;
+
+cleanup:
+
+  if (fd != -1)
+    close(fd);
+  gc_free(&gc);
+  return ret;
+}
+
+result_t
+verify_cert(struct tls_session *session, openvpn_x509_cert_t *cert, int cert_depth)
+{
+  result_t ret = FAILURE;
+  char *subject = NULL;
+  char common_name[TLS_USERNAME_LEN] = {0};
+  const struct tls_options *opt;
+  struct gc_arena gc = gc_new();
+
+  opt = session->opt;
+  ASSERT (opt);
+
+  session->verified = false;
+
+  /* get the X509 name */
+  subject = x509_get_subject(cert, &gc);
+  if (!subject)
+    {
+	msg (D_TLS_ERRORS, "VERIFY ERROR: depth=%d, could not extract X509 "
+	    "subject string from certificate", cert_depth);
+	goto cleanup;
+    }
+
+  /* enforce character class restrictions in X509 name */
+  string_mod_remap_name (subject, X509_NAME_CHAR_CLASS);
+  string_replace_leading (subject, '-', '_');
+
+  /* extract the username (default is CN) */
+  if (SUCCESS != x509_get_username (common_name, TLS_USERNAME_LEN,
+      opt->x509_username_field, cert))
+    {
+      if (!cert_depth)
+	{
+	  msg (D_TLS_ERRORS, "VERIFY ERROR: could not extract %s from X509 "
+	      "subject string ('%s') -- note that the username length is "
+	      "limited to %d characters",
+	       opt->x509_username_field,
+		 subject,
+		 TLS_USERNAME_LEN);
+	  goto cleanup;
+	}
+    }
+
+  /* enforce character class restrictions in common name */
+  string_mod_remap_name (common_name, COMMON_NAME_CHAR_CLASS);
+
+  /* warn if cert chain is too deep */
+  if (cert_depth >= MAX_CERT_DEPTH)
+    {
+      msg (D_TLS_ERRORS, "TLS Error: Convoluted certificate chain detected with depth [%d] greater than %d", cert_depth, MAX_CERT_DEPTH);
+      goto cleanup;			/* Reject connection */
+    }
+
+  /* verify level 1 cert, i.e. the CA that signed our leaf cert */
+  if (cert_depth == 1 && opt->verify_hash)
+    {
+      unsigned char *sha1_hash = x509_get_sha1_hash(cert, &gc);
+      if (memcmp (sha1_hash, opt->verify_hash, SHA_DIGEST_LENGTH))
+      {
+	msg (D_TLS_ERRORS, "TLS Error: level-1 certificate hash verification failed");
+	goto cleanup;
+      }
+    }
+
+  /* save common name in session object */
+  if (cert_depth == 0)
+    set_common_name (session, common_name);
+
+  session->verify_maxlevel = max_int (session->verify_maxlevel, cert_depth);
+
+  /* export certificate values to the environment */
+  verify_cert_set_env(opt->es, cert, cert_depth, subject, common_name
+#ifdef ENABLE_X509_TRACK
+      , opt->x509_track
+#endif
+      );
+
+  /* export current untrusted IP */
+  setenv_untrusted (session);
+
+  /* If this is the peer's own certificate, verify it */
+  if (cert_depth == 0 && SUCCESS != verify_peer_cert(opt, cert, subject, common_name))
+    goto cleanup;
+
+  /* call --tls-verify plug-in(s), if registered */
+  if (SUCCESS != verify_cert_call_plugin(opt->plugins, opt->es, cert_depth, cert, subject))
+    goto cleanup;
+
+  /* run --tls-verify script */
+  if (opt->verify_command && SUCCESS != verify_cert_call_command(opt->verify_command,
+      opt->es, cert_depth, cert, subject, opt->verify_export_cert))
+    goto cleanup;
+
+  /* check peer cert against CRL */
+  if (opt->crl_file)
+    {
+      if (opt->ssl_flags & SSLF_CRL_VERIFY_DIR)
+      {
+	if (SUCCESS != verify_check_crl_dir(opt->crl_file, cert))
+	  goto cleanup;
+      }
+      else
+      {
+	if (SUCCESS != x509_verify_crl(opt->crl_file, cert, subject))
+	  goto cleanup;
+      }
+    }
+
+  msg (D_HANDSHAKE, "VERIFY OK: depth=%d, %s", cert_depth, subject);
+  session->verified = true;
+  ret = SUCCESS;
+
+cleanup:
+
+  if (ret != SUCCESS)
+    {
+      tls_clear_error(); /* always? */
+      session->verified = false; /* double sure? */
+    }
+  gc_free(&gc);
+
+  return ret;
+}
+
+/* ***************************************************************************
+ * Functions for the management of deferred authentication when using
+ * user/password authentication.
+ *************************************************************************** */
+
+#ifdef ENABLE_DEF_AUTH
+/* key_state_test_auth_control_file return values,
+   NOTE: acf_merge indexing depends on these values */
+#define ACF_UNDEFINED 0
+#define ACF_SUCCEEDED 1
+#define ACF_DISABLED  2
+#define ACF_FAILED    3
+#endif
+
+#ifdef MANAGEMENT_DEF_AUTH
+void
+man_def_auth_set_client_reason (struct tls_multi *multi, const char *client_reason)
+{
+  if (multi->client_reason)
+    {
+      free (multi->client_reason);
+      multi->client_reason = NULL;
+    }
+  if (client_reason && strlen (client_reason))
+    /* FIXME: Last alloc will never be freed */
+    multi->client_reason = string_alloc (client_reason, NULL);
+}
+
+static inline unsigned int
+man_def_auth_test (const struct key_state *ks)
+{
+  if (management_enable_def_auth (management))
+    return ks->mda_status;
+  else
+    return ACF_DISABLED;
+}
+#endif
+
+#ifdef PLUGIN_DEF_AUTH
+
+/*
+ * auth_control_file functions
+ */
+
+void
+key_state_rm_auth_control_file (struct key_state *ks)
+{
+  if (ks && ks->auth_control_file)
+    {
+      platform_unlink (ks->auth_control_file);
+      free (ks->auth_control_file);
+      ks->auth_control_file = NULL;
+    }
+}
+
+static void
+key_state_gen_auth_control_file (struct key_state *ks, const struct tls_options *opt)
+{
+  struct gc_arena gc = gc_new ();
+  const char *acf;
+
+  key_state_rm_auth_control_file (ks);
+  acf = create_temp_file (opt->tmp_dir, "acf", &gc);
+  if (acf) {
+    ks->auth_control_file = string_alloc (acf, NULL);
+    setenv_str (opt->es, "auth_control_file", ks->auth_control_file);
+  } /* FIXME: Should have better error handling? */
+
+  gc_free (&gc);
+}
+
+static unsigned int
+key_state_test_auth_control_file (struct key_state *ks)
+{
+  if (ks && ks->auth_control_file)
+    {
+      unsigned int ret = ks->auth_control_status;
+      if (ret == ACF_UNDEFINED)
+	{
+	  FILE *fp = fopen (ks->auth_control_file, "r");
+	  if (fp)
+	    {
+	      const int c = fgetc (fp);
+	      if (c == '1')
+		ret = ACF_SUCCEEDED;
+	      else if (c == '0')
+		ret = ACF_FAILED;
+	      fclose (fp);
+	      ks->auth_control_status = ret;
+	    }
+	}
+      return ret;
+    }
+  return ACF_DISABLED;
+}
+
+#endif
+
+/*
+ * Return current session authentication state.  Return
+ * value is TLS_AUTHENTICATION_x.
+ */
+
+int
+tls_authentication_status (struct tls_multi *multi, const int latency)
+{
+  bool deferred = false;
+  bool success = false;
+  bool active = false;
+
+#ifdef ENABLE_DEF_AUTH
+  static const unsigned char acf_merge[] =
+    {
+      ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_UNDEFINED */
+      ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_SUCCEEDED */
+      ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_DISABLED */
+      ACF_FAILED,    /* s1=ACF_UNDEFINED s2=ACF_FAILED */
+      ACF_UNDEFINED, /* s1=ACF_SUCCEEDED s2=ACF_UNDEFINED */
+      ACF_SUCCEEDED, /* s1=ACF_SUCCEEDED s2=ACF_SUCCEEDED */
+      ACF_SUCCEEDED, /* s1=ACF_SUCCEEDED s2=ACF_DISABLED */
+      ACF_FAILED,    /* s1=ACF_SUCCEEDED s2=ACF_FAILED */
+      ACF_UNDEFINED, /* s1=ACF_DISABLED  s2=ACF_UNDEFINED */
+      ACF_SUCCEEDED, /* s1=ACF_DISABLED  s2=ACF_SUCCEEDED */
+      ACF_DISABLED,  /* s1=ACF_DISABLED  s2=ACF_DISABLED */
+      ACF_FAILED,    /* s1=ACF_DISABLED  s2=ACF_FAILED */
+      ACF_FAILED,    /* s1=ACF_FAILED    s2=ACF_UNDEFINED */
+      ACF_FAILED,    /* s1=ACF_FAILED    s2=ACF_SUCCEEDED */
+      ACF_FAILED,    /* s1=ACF_FAILED    s2=ACF_DISABLED */
+      ACF_FAILED     /* s1=ACF_FAILED    s2=ACF_FAILED */
+    };
+#endif /* ENABLE_DEF_AUTH */
+
+  if (multi)
+    {
+      int i;
+
+#ifdef ENABLE_DEF_AUTH
+      if (latency && multi->tas_last && multi->tas_last + latency >= now)
+	return TLS_AUTHENTICATION_UNDEFINED;
+      multi->tas_last = now;
+#endif /* ENABLE_DEF_AUTH */
+
+      for (i = 0; i < KEY_SCAN_SIZE; ++i)
+	{
+	  struct key_state *ks = multi->key_scan[i];
+	  if (DECRYPT_KEY_ENABLED (multi, ks))
+	    {
+	      active = true;
+	      if (ks->authenticated)
+		{
+#ifdef ENABLE_DEF_AUTH
+		  unsigned int s1 = ACF_DISABLED;
+		  unsigned int s2 = ACF_DISABLED;
+#ifdef PLUGIN_DEF_AUTH
+		  s1 = key_state_test_auth_control_file (ks);
+#endif /* PLUGIN_DEF_AUTH */
+#ifdef MANAGEMENT_DEF_AUTH
+		  s2 = man_def_auth_test (ks);
+#endif /* MANAGEMENT_DEF_AUTH */
+		  ASSERT (s1 < 4 && s2 < 4);
+		  switch (acf_merge[(s1<<2) + s2])
+		    {
+		    case ACF_SUCCEEDED:
+		    case ACF_DISABLED:
+		      success = true;
+		      ks->auth_deferred = false;
+		      break;
+		    case ACF_UNDEFINED:
+		      if (now < ks->auth_deferred_expire)
+			deferred = true;
+		      break;
+		    case ACF_FAILED:
+		      ks->authenticated = false;
+		      break;
+		    default:
+		      ASSERT (0);
+		    }
+#else /* !ENABLE_DEF_AUTH */
+		  success = true;
+#endif /* ENABLE_DEF_AUTH */
+		}
+	    }
+	}
+    }
+
+#if 0
+  dmsg (D_TLS_ERRORS, "TAS: a=%d s=%d d=%d", active, success, deferred);
+#endif
+
+  if (success)
+    return TLS_AUTHENTICATION_SUCCEEDED;
+  else if (!active || deferred)
+    return TLS_AUTHENTICATION_DEFERRED;
+  else
+    return TLS_AUTHENTICATION_FAILED;
+}
+
+#ifdef MANAGEMENT_DEF_AUTH
+/*
+ * For deferred auth, this is where the management interface calls (on server)
+ * to indicate auth failure/success.
+ */
+bool
+tls_authenticate_key (struct tls_multi *multi, const unsigned int mda_key_id, const bool auth, const char *client_reason)
+{
+  bool ret = false;
+  if (multi)
+    {
+      int i;
+      man_def_auth_set_client_reason (multi, client_reason);
+      for (i = 0; i < KEY_SCAN_SIZE; ++i)
+	{
+	  struct key_state *ks = multi->key_scan[i];
+	  if (ks->mda_key_id == mda_key_id)
+	    {
+	      ks->mda_status = auth ? ACF_SUCCEEDED : ACF_FAILED;
+	      ret = true;
+	    }
+	}
+    }
+  return ret;
+}
+#endif
+
+
+/* ****************************************************************************
+ * Functions to verify username and password
+ *
+ * Authenticate a client using username/password.
+ * Runs on server.
+ *
+ * If you want to add new authentication methods,
+ * this is the place to start.
+ *************************************************************************** */
+
+/*
+ * Verify the user name and password using a script
+ */
+static bool
+verify_user_pass_script (struct tls_session *session, const struct user_pass *up)
+{
+  struct gc_arena gc = gc_new ();
+  struct argv argv = argv_new ();
+  const char *tmp_file = "";
+  bool ret = false;
+
+  /* Is username defined? */
+  if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username))
+    {
+      /* Set environmental variables prior to calling script */
+      setenv_str (session->opt->es, "script_type", "user-pass-verify");
+
+      if (session->opt->auth_user_pass_verify_script_via_file)
+	{
+	  struct status_output *so;
+
+	  tmp_file = create_temp_file (session->opt->tmp_dir, "up", &gc);
+          if( tmp_file ) {
+	    so = status_open (tmp_file, 0, -1, NULL, STATUS_OUTPUT_WRITE);
+	    status_printf (so, "%s", up->username);
+	    status_printf (so, "%s", up->password);
+	    if (!status_close (so))
+	      {
+		msg (D_TLS_ERRORS, "TLS Auth Error: could not write username/password to file: %s",
+		     tmp_file);
+		goto done;
+	      }
+          } else {
+            msg (D_TLS_ERRORS, "TLS Auth Error: could not create write "
+                 "username/password to temp file");
+          }
+	}
+      else
+	{
+	  setenv_str (session->opt->es, "username", up->username);
+	  setenv_str (session->opt->es, "password", up->password);
+	}
+
+      /* setenv incoming cert common name for script */
+      setenv_str (session->opt->es, "common_name", session->common_name);
+
+      /* setenv client real IP address */
+      setenv_untrusted (session);
+
+      /* format command line */
+      argv_printf (&argv, "%sc %s", session->opt->auth_user_pass_verify_script, tmp_file);
+
+      /* call command */
+      ret = openvpn_run_script (&argv, session->opt->es, 0,
+				"--auth-user-pass-verify");
+
+      if (!session->opt->auth_user_pass_verify_script_via_file)
+	setenv_del (session->opt->es, "password");
+    }
+  else
+    {
+      msg (D_TLS_ERRORS, "TLS Auth Error: peer provided a blank username");
+    }
+
+ done:
+  if (tmp_file && strlen (tmp_file) > 0)
+    platform_unlink (tmp_file);
+
+  argv_reset (&argv);
+  gc_free (&gc);
+  return ret;
+}
+
+/*
+ * Verify the username and password using a plugin
+ */
+static int
+verify_user_pass_plugin (struct tls_session *session, const struct user_pass *up, const char *raw_username)
+{
+  int retval = OPENVPN_PLUGIN_FUNC_ERROR;
+  struct key_state *ks = &session->key[KS_PRIMARY]; 	   /* primary key */
+
+  /* Is username defined? */
+  if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username))
+    {
+      /* set username/password in private env space */
+      setenv_str (session->opt->es, "username", (raw_username ? raw_username : up->username));
+      setenv_str (session->opt->es, "password", up->password);
+
+      /* setenv incoming cert common name for script */
+      setenv_str (session->opt->es, "common_name", session->common_name);
+
+      /* setenv client real IP address */
+      setenv_untrusted (session);
+
+#ifdef PLUGIN_DEF_AUTH
+      /* generate filename for deferred auth control file */
+      key_state_gen_auth_control_file (ks, session->opt);
+#endif
+
+      /* call command */
+      retval = plugin_call (session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, NULL, NULL, session->opt->es);
+
+#ifdef PLUGIN_DEF_AUTH
+      /* purge auth control filename (and file itself) for non-deferred returns */
+      if (retval != OPENVPN_PLUGIN_FUNC_DEFERRED)
+	key_state_rm_auth_control_file (ks);
+#endif
+
+      setenv_del (session->opt->es, "password");
+      if (raw_username)
+        setenv_str (session->opt->es, "username", up->username);
+    }
+  else
+    {
+      msg (D_TLS_ERRORS, "TLS Auth Error (verify_user_pass_plugin): peer provided a blank username");
+    }
+
+  return retval;
+}
+
+
+#ifdef MANAGEMENT_DEF_AUTH
+/*
+ * MANAGEMENT_DEF_AUTH internal ssl_verify.c status codes
+ */
+#define KMDA_ERROR   0
+#define KMDA_SUCCESS 1
+#define KMDA_UNDEF   2
+#define KMDA_DEF     3
+
+static int
+verify_user_pass_management (struct tls_session *session, const struct user_pass *up, const char *raw_username)
+{
+  int retval = KMDA_ERROR;
+  struct key_state *ks = &session->key[KS_PRIMARY]; 	   /* primary key */
+
+  /* Is username defined? */
+  if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username))
+    {
+      /* set username/password in private env space */
+      setenv_str (session->opt->es, "username", (raw_username ? raw_username : up->username));
+      setenv_str (session->opt->es, "password", up->password);
+
+      /* setenv incoming cert common name for script */
+      setenv_str (session->opt->es, "common_name", session->common_name);
+
+      /* setenv client real IP address */
+      setenv_untrusted (session);
+
+      if (management)
+	management_notify_client_needing_auth (management, ks->mda_key_id, session->opt->mda_context, session->opt->es);
+
+      setenv_del (session->opt->es, "password");
+      if (raw_username)
+        setenv_str (session->opt->es, "username", up->username);
+
+      retval = KMDA_SUCCESS;
+    }
+  else
+    {
+      msg (D_TLS_ERRORS, "TLS Auth Error (verify_user_pass_management): peer provided a blank username");
+    }
+
+  return retval;
+}
+#endif
+
+/*
+ * Main username/password verification entry point
+ */
+void
+verify_user_pass(struct user_pass *up, struct tls_multi *multi,
+    struct tls_session *session)
+{
+  int s1 = OPENVPN_PLUGIN_FUNC_SUCCESS;
+  bool s2 = true;
+  struct key_state *ks = &session->key[KS_PRIMARY]; 	   /* primary key */
+
+  struct gc_arena gc = gc_new ();
+  char *raw_username = NULL;
+
+#ifdef MANAGEMENT_DEF_AUTH
+  int man_def_auth = KMDA_UNDEF;
+
+  if (management_enable_def_auth (management))
+    man_def_auth = KMDA_DEF;
+#endif
+
+  /*
+   * Preserve the raw username before string_mod remapping, for plugins
+   * and management clients when in --compat-names mode
+   */
+  if (compat_flag (COMPAT_FLAG_QUERY | COMPAT_NAMES))
+    {
+      ALLOC_ARRAY_CLEAR_GC (raw_username, char, USER_PASS_LEN, &gc);
+      strcpy (raw_username, up->username);
+      string_mod (raw_username, CC_PRINT, CC_CRLF, '_');
+    }
+
+  /* enforce character class restrictions in username/password */
+  string_mod_remap_name (up->username, COMMON_NAME_CHAR_CLASS);
+  string_mod (up->password, CC_PRINT, CC_CRLF, '_');
+
+  /* call plugin(s) and/or script */
+#ifdef MANAGEMENT_DEF_AUTH
+  if (man_def_auth == KMDA_DEF)
+    man_def_auth = verify_user_pass_management (session, up, raw_username);
+#endif
+  if (plugin_defined (session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY))
+    s1 = verify_user_pass_plugin (session, up, raw_username);
+  if (session->opt->auth_user_pass_verify_script)
+    s2 = verify_user_pass_script (session, up);
+
+  /* check sizing of username if it will become our common name */
+  if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) && strlen (up->username) >= TLS_USERNAME_LEN)
+    {
+      msg (D_TLS_ERRORS, "TLS Auth Error: --username-as-common name specified and username is longer than the maximum permitted Common Name length of %d characters", TLS_USERNAME_LEN);
+      s1 = OPENVPN_PLUGIN_FUNC_ERROR;
+    }
+
+  /* auth succeeded? */
+  if ((s1 == OPENVPN_PLUGIN_FUNC_SUCCESS
+#ifdef PLUGIN_DEF_AUTH
+       || s1 == OPENVPN_PLUGIN_FUNC_DEFERRED
+#endif
+       ) && s2
+#ifdef MANAGEMENT_DEF_AUTH
+       && man_def_auth != KMDA_ERROR
+#endif
+      && tls_lock_username (multi, up->username))
+    {
+      ks->authenticated = true;
+#ifdef PLUGIN_DEF_AUTH
+      if (s1 == OPENVPN_PLUGIN_FUNC_DEFERRED)
+	ks->auth_deferred = true;
+#endif
+#ifdef MANAGEMENT_DEF_AUTH
+      if (man_def_auth != KMDA_UNDEF)
+	ks->auth_deferred = true;
+#endif
+      if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME))
+	set_common_name (session, up->username);
+#ifdef ENABLE_DEF_AUTH
+      msg (D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s",
+	   ks->auth_deferred ? "deferred" : "succeeded",
+	   up->username,
+	   (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
+#else
+      msg (D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s",
+	   "succeeded",
+	   up->username,
+	   (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
+#endif
+    }
+  else
+    {
+      msg (D_TLS_ERRORS, "TLS Auth Error: Auth Username/Password verification failed for peer");
+    }
+
+  gc_free (&gc);
+}
+
+void
+verify_final_auth_checks(struct tls_multi *multi, struct tls_session *session)
+{
+  struct key_state *ks = &session->key[KS_PRIMARY]; 	   /* primary key */
+
+  /* While it shouldn't really happen, don't allow the common name to be NULL */
+  if (!session->common_name)
+    set_common_name (session, "");
+
+  /* Don't allow the CN to change once it's been locked */
+  if (ks->authenticated && multi->locked_cn)
+    {
+      const char *cn = session->common_name;
+      if (cn && strcmp (cn, multi->locked_cn))
+	{
+	  msg (D_TLS_ERRORS, "TLS Auth Error: TLS object CN attempted to change from '%s' to '%s' -- tunnel disabled",
+	       multi->locked_cn,
+	       cn);
+
+	  /* change the common name back to its original value and disable the tunnel */
+	  set_common_name (session, multi->locked_cn);
+	  tls_deauthenticate (multi);
+	}
+    }
+
+  /* Don't allow the cert hashes to change once they have been locked */
+  if (ks->authenticated && multi->locked_cert_hash_set)
+    {
+      const struct cert_hash_set *chs = session->cert_hash_set;
+      if (chs && !cert_hash_compare (chs, multi->locked_cert_hash_set))
+	{
+	  msg (D_TLS_ERRORS, "TLS Auth Error: TLS object CN=%s client-provided SSL certs unexpectedly changed during mid-session reauth",
+	       session->common_name);
+
+	  /* disable the tunnel */
+	  tls_deauthenticate (multi);
+	}
+    }
+
+  /* verify --client-config-dir based authentication */
+  if (ks->authenticated && session->opt->client_config_dir_exclusive)
+    {
+      struct gc_arena gc = gc_new ();
+
+      const char *cn = session->common_name;
+      const char *path = gen_path (session->opt->client_config_dir_exclusive, cn, &gc);
+      if (!cn || !strcmp (cn, CCD_DEFAULT) || !test_file (path))
+	{
+	  ks->authenticated = false;
+	  msg (D_TLS_ERRORS, "TLS Auth Error: --client-config-dir authentication failed for common name '%s' file='%s'",
+	       session->common_name,
+	       path ? path : "UNDEF");
+	}
+
+      gc_free (&gc);
+    }
+}
+#endif /* defined(ENABLE_CRYPTO) && defined(ENABLE_SSL) */