/*
  *  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 PKCS #11 mbed TLS backend

  */
 

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #elif defined(_MSC_VER)
 #include "config-msvc.h"
 #endif
 

 #include "syshead.h"
 

 #if defined(ENABLE_PKCS11) && defined(ENABLE_CRYPTO_MBEDTLS)

 
 #include "errlevel.h"
 #include "pkcs11_backend.h"

 #include "ssl_verify_backend.h"

 #include <mbedtls/x509.h>

 static bool
 pkcs11_get_x509_cert(pkcs11h_certificate_t pkcs11_cert, mbedtls_x509_crt *cert)

 {

     unsigned char *cert_blob = NULL;
     size_t cert_blob_size = 0;
     bool ret = false;

     if (pkcs11h_certificate_getCertificateBlob(pkcs11_cert, NULL,
                                                &cert_blob_size) != CKR_OK)

     {

         msg(M_WARN, "PKCS#11: Cannot retrieve certificate object size");

         goto cleanup;
     }
 

     check_malloc_return((cert_blob = calloc(1, cert_blob_size)));
     if (pkcs11h_certificate_getCertificateBlob(pkcs11_cert, cert_blob,
                                                &cert_blob_size) != CKR_OK)

     {

         msg(M_WARN, "PKCS#11: Cannot retrieve certificate object");

         goto cleanup;
     }
 

     if (!mbed_ok(mbedtls_x509_crt_parse(cert, cert_blob, cert_blob_size)))

     {

         msg(M_WARN, "PKCS#11: Could not parse certificate");

         goto cleanup;
     }
 

     ret = true;

 cleanup:

     free(cert_blob);

     return ret;

 }
 

 static bool
 pkcs11_sign(void *pkcs11_cert, const void *src, size_t src_len,
             void *dst, size_t dst_len)
 {
     return CKR_OK == pkcs11h_certificate_signAny(pkcs11_cert, CKM_RSA_PKCS,
                                                  src, src_len, dst, &dst_len);
 }
 
 int
 pkcs11_init_tls_session(pkcs11h_certificate_t certificate,
                         struct tls_root_ctx *const ssl_ctx)
 {
     ASSERT(NULL != ssl_ctx);
 
     ssl_ctx->pkcs11_cert = certificate;
 
     ALLOC_OBJ_CLEAR(ssl_ctx->crt_chain, mbedtls_x509_crt);
     if (!pkcs11_get_x509_cert(certificate, ssl_ctx->crt_chain))
     {
         msg(M_WARN, "PKCS#11: Cannot initialize certificate");
         return 1;
     }
 
     if (tls_ctx_use_external_signing_func(ssl_ctx, pkcs11_sign, certificate))
     {
         msg(M_WARN, "PKCS#11: Cannot register signing function");
         return 1;
     }
 
     return 0;
 }
 

 char *

 pkcs11_certificate_dn(pkcs11h_certificate_t cert, struct gc_arena *gc)

 {

     char *ret = NULL;

     mbedtls_x509_crt mbed_crt = { 0 };

     if (!pkcs11_get_x509_cert(cert, &mbed_crt))

     {

         msg(M_WARN, "PKCS#11: Cannot retrieve mbed TLS certificate object");

         goto cleanup;
     }

     if (!(ret = x509_get_subject(&mbed_crt, gc)))

     {

         msg(M_WARN, "PKCS#11: mbed TLS cannot parse subject");

         goto cleanup;
     }

 
 cleanup:

     mbedtls_x509_crt_free(&mbed_crt);

     return ret;

 }
 
 int

 pkcs11_certificate_serial(pkcs11h_certificate_t cert, char *serial,
                           size_t serial_len)

 {

     int ret = 1;

     mbedtls_x509_crt mbed_crt = { 0 };

     if (!pkcs11_get_x509_cert(cert, &mbed_crt))

     {

         msg(M_WARN, "PKCS#11: Cannot retrieve mbed TLS certificate object");

         goto cleanup;
     }

     if (mbedtls_x509_serial_gets(serial, serial_len, &mbed_crt.serial) < 0)

     {

         msg(M_WARN, "PKCS#11: mbed TLS cannot parse serial");

         goto cleanup;
     }

     ret = 0;

 cleanup:

     mbedtls_x509_crt_free(&mbed_crt);

     return ret;

 }

 #endif /* defined(ENABLE_PKCS11) && defined(ENABLE_CRYPTO_MBEDTLS) */