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/*
* QEMU VNC display driver: VeNCrypt authentication setup
*
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
* Copyright (C) 2006 Fabrice Bellard
* Copyright (C) 2009 Red Hat, Inc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "vnc.h"
static void start_auth_vencrypt_subauth(VncState *vs)
{
switch (vs->subauth) {
case VNC_AUTH_VENCRYPT_TLSNONE:
case VNC_AUTH_VENCRYPT_X509NONE:
VNC_DEBUG("Accept TLS auth none\n");
vnc_write_u32(vs, 0); /* Accept auth completion */
start_client_init(vs);
break;
case VNC_AUTH_VENCRYPT_TLSVNC:
case VNC_AUTH_VENCRYPT_X509VNC:
VNC_DEBUG("Start TLS auth VNC\n");
start_auth_vnc(vs);
break;
#ifdef CONFIG_VNC_SASL
case VNC_AUTH_VENCRYPT_TLSSASL:
case VNC_AUTH_VENCRYPT_X509SASL:
VNC_DEBUG("Start TLS auth SASL\n");
start_auth_sasl(vs);
break;
#endif /* CONFIG_VNC_SASL */
default: /* Should not be possible, but just in case */
VNC_DEBUG("Reject subauth %d server bug\n", vs->auth);
vnc_write_u8(vs, 1);
if (vs->minor >= 8) {
static const char err[] = "Unsupported authentication type";
vnc_write_u32(vs, sizeof(err));
vnc_write(vs, err, sizeof(err));
}
vnc_client_error(vs);
}
}
static void vnc_tls_handshake_io(void *opaque);
static int vnc_start_vencrypt_handshake(struct VncState *vs) {
int ret;
if ((ret = gnutls_handshake(vs->tls.session)) < 0) {
if (!gnutls_error_is_fatal(ret)) {
VNC_DEBUG("Handshake interrupted (blocking)\n");
if (!gnutls_record_get_direction(vs->tls.session))
qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs);
else
qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs);
return 0;
}
VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret));
vnc_client_error(vs);
return -1;
}
if (vs->vd->tls.x509verify) {
if (vnc_tls_validate_certificate(vs) < 0) {
VNC_DEBUG("Client verification failed\n");
vnc_client_error(vs);
return -1;
} else {
VNC_DEBUG("Client verification passed\n");
}
}
VNC_DEBUG("Handshake done, switching to TLS data mode\n");
vs->tls.wiremode = VNC_WIREMODE_TLS;
qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, vnc_client_write, vs);
start_auth_vencrypt_subauth(vs);
return 0;
}
static void vnc_tls_handshake_io(void *opaque) {
struct VncState *vs = (struct VncState *)opaque;
VNC_DEBUG("Handshake IO continue\n");
vnc_start_vencrypt_handshake(vs);
}
#define NEED_X509_AUTH(vs) \
((vs)->subauth == VNC_AUTH_VENCRYPT_X509NONE || \
(vs)->subauth == VNC_AUTH_VENCRYPT_X509VNC || \
(vs)->subauth == VNC_AUTH_VENCRYPT_X509PLAIN || \
(vs)->subauth == VNC_AUTH_VENCRYPT_X509SASL)
static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len)
{
int auth = read_u32(data, 0);
if (auth != vs->subauth) {
VNC_DEBUG("Rejecting auth %d\n", auth);
vnc_write_u8(vs, 0); /* Reject auth */
vnc_flush(vs);
vnc_client_error(vs);
} else {
VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth);
vnc_write_u8(vs, 1); /* Accept auth */
vnc_flush(vs);
if (vnc_tls_client_setup(vs, NEED_X509_AUTH(vs)) < 0) {
VNC_DEBUG("Failed to setup TLS\n");
return 0;
}
VNC_DEBUG("Start TLS VeNCrypt handshake process\n");
if (vnc_start_vencrypt_handshake(vs) < 0) {
VNC_DEBUG("Failed to start TLS handshake\n");
return 0;
}
}
return 0;
}
static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len)
{
if (data[0] != 0 ||
data[1] != 2) {
VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]);
vnc_write_u8(vs, 1); /* Reject version */
vnc_flush(vs);
vnc_client_error(vs);
} else {
VNC_DEBUG("Sending allowed auth %d\n", vs->subauth);
vnc_write_u8(vs, 0); /* Accept version */
vnc_write_u8(vs, 1); /* Number of sub-auths */
vnc_write_u32(vs, vs->subauth); /* The supported auth */
vnc_flush(vs);
vnc_read_when(vs, protocol_client_vencrypt_auth, 4);
}
return 0;
}
void start_auth_vencrypt(VncState *vs)
{
/* Send VeNCrypt version 0.2 */
vnc_write_u8(vs, 0);
vnc_write_u8(vs, 2);
vnc_read_when(vs, protocol_client_vencrypt_init, 2);
}
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