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/*
* 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 OpenSSL Backend
*/
#include "syshead.h"
#include "errlevel.h"
#include "buffer.h"
#include "misc.h"
#include "manage.h"
#include "memdbg.h"
#include "ssl_backend.h"
#include "ssl_common.h"
#include "ssl_verify_openssl.h"
#include <openssl/err.h>
#include <openssl/pkcs12.h>
#include <openssl/x509.h>
#include <openssl/crypto.h>
/*
* Allocate space in SSL objects in which to store a struct tls_session
* pointer back to parent.
*
*/
int mydata_index; /* GLOBAL */
void
tls_init_lib()
{
SSL_library_init();
SSL_load_error_strings();
OpenSSL_add_all_algorithms ();
mydata_index = SSL_get_ex_new_index(0, "struct session *", NULL, NULL, NULL);
ASSERT (mydata_index >= 0);
}
void
tls_free_lib()
{
EVP_cleanup();
ERR_free_strings();
}
void
tls_clear_error()
{
ERR_clear_error ();
}
/*
* OpenSSL callback to get a temporary RSA key, mostly
* used for export ciphers.
*/
static RSA *
tmp_rsa_cb (SSL * s, int is_export, int keylength)
{
static RSA *rsa_tmp = NULL;
if (rsa_tmp == NULL)
{
msg (D_HANDSHAKE, "Generating temp (%d bit) RSA key", keylength);
rsa_tmp = RSA_generate_key (keylength, RSA_F4, NULL, NULL);
}
return (rsa_tmp);
}
void
tls_ctx_server_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
ctx->ctx = SSL_CTX_new (TLSv1_server_method ());
if (ctx->ctx == NULL)
msg (M_SSLERR, "SSL_CTX_new TLSv1_server_method");
SSL_CTX_set_tmp_rsa_callback (ctx->ctx, tmp_rsa_cb);
}
void
tls_ctx_client_new(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
ctx->ctx = SSL_CTX_new (TLSv1_client_method ());
if (ctx->ctx == NULL)
msg (M_SSLERR, "SSL_CTX_new TLSv1_client_method");
}
void
tls_ctx_free(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
if (NULL != ctx->ctx)
SSL_CTX_free (ctx->ctx);
ctx->ctx = NULL;
}
bool tls_ctx_initialised(struct tls_root_ctx *ctx)
{
ASSERT(NULL != ctx);
return NULL != ctx->ctx;
}
void
tls_ctx_load_dh_params (struct tls_root_ctx *ctx, const char *dh_file
#if ENABLE_INLINE_FILES
, const char *dh_file_inline
#endif /* ENABLE_INLINE_FILES */
)
{
DH *dh;
BIO *bio;
ASSERT(NULL != ctx);
#if ENABLE_INLINE_FILES
if (!strcmp (dh_file, INLINE_FILE_TAG) && dh_file_inline)
{
if (!(bio = BIO_new_mem_buf ((char *)dh_file_inline, -1)))
msg (M_SSLERR, "Cannot open memory BIO for inline DH parameters");
}
else
#endif /* ENABLE_INLINE_FILES */
{
/* Get Diffie Hellman Parameters */
if (!(bio = BIO_new_file (dh_file, "r")))
msg (M_SSLERR, "Cannot open %s for DH parameters", dh_file);
}
dh = PEM_read_bio_DHparams (bio, NULL, NULL, NULL);
BIO_free (bio);
if (!dh)
msg (M_SSLERR, "Cannot load DH parameters from %s", dh_file);
if (!SSL_CTX_set_tmp_dh (ctx->ctx, dh))
msg (M_SSLERR, "SSL_CTX_set_tmp_dh");
msg (D_TLS_DEBUG_LOW, "Diffie-Hellman initialized with %d bit key",
8 * DH_size (dh));
DH_free (dh);
}
void
show_available_tls_ciphers ()
{
SSL_CTX *ctx;
SSL *ssl;
const char *cipher_name;
int priority = 0;
ctx = SSL_CTX_new (TLSv1_method ());
if (!ctx)
msg (M_SSLERR, "Cannot create SSL_CTX object");
ssl = SSL_new (ctx);
if (!ssl)
msg (M_SSLERR, "Cannot create SSL object");
printf ("Available TLS Ciphers,\n");
printf ("listed in order of preference:\n\n");
while ((cipher_name = SSL_get_cipher_list (ssl, priority++)))
printf ("%s\n", cipher_name);
printf ("\n");
SSL_free (ssl);
SSL_CTX_free (ctx);
}
void
get_highest_preference_tls_cipher (char *buf, int size)
{
SSL_CTX *ctx;
SSL *ssl;
const char *cipher_name;
ctx = SSL_CTX_new (TLSv1_method ());
if (!ctx)
msg (M_SSLERR, "Cannot create SSL_CTX object");
ssl = SSL_new (ctx);
if (!ssl)
msg (M_SSLERR, "Cannot create SSL object");
cipher_name = SSL_get_cipher_list (ssl, 0);
strncpynt (buf, cipher_name, size);
SSL_free (ssl);
SSL_CTX_free (ctx);
}
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