1/*
2 *  OpenVPN -- An application to securely tunnel IP networks
3 *             over a single TCP/UDP port, with support for SSL/TLS-based
4 *             session authentication and key exchange,
5 *             packet encryption, packet authentication, and
6 *             packet compression.
7 *
8 *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
9 *  Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
10 *
11 *  This program is free software; you can redistribute it and/or modify
12 *  it under the terms of the GNU General Public License version 2
13 *  as published by the Free Software Foundation.
14 *
15 *  This program is distributed in the hope that it will be useful,
16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *  GNU General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License
21 *  along with this program (see the file COPYING included with this
22 *  distribution); if not, write to the Free Software Foundation, Inc.,
23 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
24 */
25
26/**
27 * @file Control Channel Verification Module PolarSSL backend
28 */
29
30#ifndef SSL_VERIFY_POLARSSL_H_
31#define SSL_VERIFY_POLARSSL_H_
32
33#include "syshead.h"
34#include "misc.h"
35#include "manage.h"
36#include <polarssl/x509.h>
37
38#ifndef __OPENVPN_X509_CERT_T_DECLARED
39#define __OPENVPN_X509_CERT_T_DECLARED
40typedef x509_cert openvpn_x509_cert_t;
41#endif
42
43/** @name Function for authenticating a new connection from a remote OpenVPN peer
44 *  @{ */
45
46/**
47 * Verify that the remote OpenVPN peer's certificate allows setting up a
48 * VPN tunnel.
49 * @ingroup control_tls
50 *
51 * This callback function is called when a new TLS session is being setup to
52 * determine whether the remote OpenVPN peer's certificate is allowed to
53 * connect. It is called for once for every certificate in the chain. The
54 * callback functionality is configured in the \c init_ssl() function, which
55 * calls the PolarSSL library's \c ssl_set_verify_callback() function with \c
56 * verify_callback() as its callback argument.
57 *
58 * It checks *flags and registers the certificate hash. If these steps succeed,
59 * it calls the \c verify_cert() function, which performs OpenVPN-specific
60 * verification.
61 *
62 * @param session_obj  - The OpenVPN \c tls_session associated with this object,
63 *                       as set during SSL session setup.
64 * @param cert         - The certificate used by PolarSSL.
65 * @param cert_depth   - The depth of the current certificate in the chain, with
66 *                       0 being the actual certificate.
67 * @param flags        - Whether the remote OpenVPN peer's certificate
68 *                       passed verification.  A value of 0 means it
69 *                       verified successfully, any other value means it
70 *                       failed. \c verify_callback() is considered to have
71 *                       ok'ed this certificate if flags is 0 when it returns.
72 *
73 * @return The return value is 0 unless a fatal error occurred.
74 */
75int verify_callback (void *session_obj, x509_cert *cert, int cert_depth,
76    int *flags);
77
78/** @} name Function for authenticating a new connection from a remote OpenVPN peer */
79
80#endif /* SSL_VERIFY_POLARSSL_H_ */
81