/*
  *  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) 2002-2018 OpenVPN Inc <sales@openvpn.net>
  *  Copyright (C) 2010-2018 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; if not, write to the Free Software Foundation, Inc.,
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  */
 
 /**

  * @file Control Channel Verification Module mbed TLS backend

  */
 

 #ifndef SSL_VERIFY_MBEDTLS_H_
 #define SSL_VERIFY_MBEDTLS_H_

 
 #include "syshead.h"

 #include <mbedtls/x509_crt.h>

 #ifndef __OPENVPN_X509_CERT_T_DECLARED
 #define __OPENVPN_X509_CERT_T_DECLARED

 typedef mbedtls_x509_crt openvpn_x509_cert_t;

 #endif

 
 /** @name Function for authenticating a new connection from a remote OpenVPN peer
  *  @{ */
 
 /**
  * Verify that the remote OpenVPN peer's certificate allows setting up a
  * VPN tunnel.
  * @ingroup control_tls
  *
  * This callback function is called when a new TLS session is being setup to
  * determine whether the remote OpenVPN peer's certificate is allowed to
  * connect. It is called for once for every certificate in the chain. The

  * callback functionality is configured in the \c key_state_ssl_init() function,
  * which calls the mbed TLS library's \c mbedtls_ssl_conf_verify() function with
  * \c verify_callback() as its callback argument.

  *

  * It checks *flags and registers the certificate hash. If these steps succeed,
  * it calls the \c verify_cert() function, which performs OpenVPN-specific
  * verification.

  *
  * @param session_obj  - The OpenVPN \c tls_session associated with this object,
  *                       as set during SSL session setup.

  * @param cert         - The certificate used by mbed TLS.

  * @param cert_depth   - The depth of the current certificate in the chain, with
  *                       0 being the actual certificate.

  * @param flags        - Whether the remote OpenVPN peer's certificate
  *                       passed verification.  A value of 0 means it
  *                       verified successfully, any other value means it
  *                       failed. \c verify_callback() is considered to have
  *                       ok'ed this certificate if flags is 0 when it returns.

  *

  * @return The return value is 0 unless a fatal error occurred.

  */

 int verify_callback(void *session_obj, mbedtls_x509_crt *cert, int cert_depth,
                     uint32_t *flags);

 
 /** @} name Function for authenticating a new connection from a remote OpenVPN peer */
 

 #endif /* SSL_VERIFY_MBEDTLS_H_ */