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/*
* Copyright (C) 2004 Red Hat Inc.
* Copyright (C) 2005 Martin Koegler
* Copyright (C) 2010 TigerVNC Team
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software 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 software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifndef HAVE_GNUTLS
#error "This source should not be compiled without HAVE_GNUTLS defined"
#endif
#include <stdlib.h>
#include <rfb/SSecurityTLS.h>
#include <rfb/SConnection.h>
#include <rfb/LogWriter.h>
#include <rfb/Exception.h>
#include <rdr/TLSInStream.h>
#include <rdr/TLSOutStream.h>
#include <gnutls/x509.h>
#define DH_BITS 1024 /* XXX This should be configurable! */
using namespace rfb;
StringParameter SSecurityTLS::X509_CertFile
("X509Cert", "Path to the X509 certificate in PEM format", "", ConfServer);
StringParameter SSecurityTLS::X509_KeyFile
("X509Key", "Path to the key of the X509 certificate in PEM format", "", ConfServer);
static LogWriter vlog("TLS");
SSecurityTLS::SSecurityTLS(bool _anon) : session(0), dh_params(0),
anon_cred(0), cert_cred(0),
anon(_anon), fis(0), fos(0)
{
certfile = X509_CertFile.getData();
keyfile = X509_KeyFile.getData();
if (gnutls_global_init() != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_global_init failed");
}
void SSecurityTLS::shutdown()
{
if (session) {
if (gnutls_bye(session, GNUTLS_SHUT_RDWR) != GNUTLS_E_SUCCESS) {
/* FIXME: Treat as non-fatal error */
vlog.error("TLS session wasn't terminated gracefully");
}
}
if (dh_params) {
gnutls_dh_params_deinit(dh_params);
dh_params = 0;
}
if (anon_cred) {
gnutls_anon_free_server_credentials(anon_cred);
anon_cred = 0;
}
if (cert_cred) {
gnutls_certificate_free_credentials(cert_cred);
cert_cred = 0;
}
if (session) {
gnutls_deinit(session);
session = 0;
}
}
SSecurityTLS::~SSecurityTLS()
{
shutdown();
if (fis)
delete fis;
if (fos)
delete fos;
delete[] keyfile;
delete[] certfile;
gnutls_global_deinit();
}
bool SSecurityTLS::processMsg(SConnection *sc)
{
rdr::InStream* is = sc->getInStream();
rdr::OutStream* os = sc->getOutStream();
vlog.debug("Process security message (session %p)", session);
if (!session) {
if (gnutls_init(&session, GNUTLS_SERVER) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_init failed");
if (gnutls_set_default_priority(session) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_set_default_priority failed");
try {
setParams(session);
}
catch(...) {
os->writeU8(0);
throw;
}
os->writeU8(1);
os->flush();
}
rdr::TLSInStream *tlsis = new rdr::TLSInStream(is, session);
rdr::TLSOutStream *tlsos = new rdr::TLSOutStream(os, session);
int err;
err = gnutls_handshake(session);
if (err != GNUTLS_E_SUCCESS) {
delete tlsis;
delete tlsos;
if (!gnutls_error_is_fatal(err)) {
vlog.debug("Deferring completion of TLS handshake: %s", gnutls_strerror(err));
return false;
}
vlog.error("TLS Handshake failed: %s", gnutls_strerror (err));
shutdown();
throw AuthFailureException("TLS Handshake failed");
}
vlog.debug("Handshake completed");
sc->setStreams(fis = tlsis, fos = tlsos);
return true;
}
void SSecurityTLS::setParams(gnutls_session_t session)
{
static const char kx_anon_priority[] = ":+ANON-ECDH:+ANON-DH";
int ret;
char *prio;
const char *err;
prio = (char*)malloc(strlen(Security::GnuTLSPriority) +
strlen(kx_anon_priority) + 1);
if (prio == NULL)
throw AuthFailureException("Not enough memory for GnuTLS priority string");
strcpy(prio, Security::GnuTLSPriority);
if (anon)
strcat(prio, kx_anon_priority);
ret = gnutls_priority_set_direct(session, prio, &err);
free(prio);
if (ret != GNUTLS_E_SUCCESS) {
if (ret == GNUTLS_E_INVALID_REQUEST)
vlog.error("GnuTLS priority syntax error at: %s", err);
throw AuthFailureException("gnutls_set_priority_direct failed");
}
if (gnutls_dh_params_init(&dh_params) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_dh_params_init failed");
if (gnutls_dh_params_generate2(dh_params, DH_BITS) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_dh_params_generate2 failed");
if (anon) {
if (gnutls_anon_allocate_server_credentials(&anon_cred) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_anon_allocate_server_credentials failed");
gnutls_anon_set_server_dh_params(anon_cred, dh_params);
if (gnutls_credentials_set(session, GNUTLS_CRD_ANON, anon_cred)
!= GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_credentials_set failed");
vlog.debug("Anonymous session has been set");
} else {
if (gnutls_certificate_allocate_credentials(&cert_cred) != GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_certificate_allocate_credentials failed");
gnutls_certificate_set_dh_params(cert_cred, dh_params);
switch (gnutls_certificate_set_x509_key_file(cert_cred, certfile, keyfile, GNUTLS_X509_FMT_PEM)) {
case GNUTLS_E_SUCCESS:
break;
case GNUTLS_E_CERTIFICATE_KEY_MISMATCH:
throw AuthFailureException("Private key does not match certificate");
case GNUTLS_E_UNSUPPORTED_CERTIFICATE_TYPE:
throw AuthFailureException("Unsupported certificate type");
default:
throw AuthFailureException("Error loading X509 certificate or key");
}
if (gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, cert_cred)
!= GNUTLS_E_SUCCESS)
throw AuthFailureException("gnutls_credentials_set failed");
vlog.debug("X509 session has been set");
}
}
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