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xrdp-proprietary/common/xrdp_tls.c

436 lines
11 KiB

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Idan Freiberg 2013-2014
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* transport layer security
*/
#include "trans.h"
#include "ssl_calls.h"
/*****************************************************************************/
struct xrdp_tls *
APP_CC
xrdp_tls_create(struct trans *trans, const char *key, const char *cert)
{
struct xrdp_tls *self;
self = (struct xrdp_tls *) g_malloc(sizeof(struct xrdp_tls), 1);
if (self != NULL)
{
self->trans = trans;
self->cert = (char *) cert;
self->key = (char *) key;
}
return self;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_accept(struct xrdp_tls *self)
{
int connection_status;
long options = 0;
/**
* SSL_OP_NO_SSLv2:
*
* We only want SSLv3 and TLSv1, so disable SSLv2.
* SSLv3 is used by, eg. Microsoft RDC for Mac OS X.
*/
options |= SSL_OP_NO_SSLv2;
/**
* SSL_OP_NO_COMPRESSION:
*
* The Microsoft RDP server does not advertise support
* for TLS compression, but alternative servers may support it.
* This was observed between early versions of the FreeRDP server
* and the FreeRDP client, and caused major performance issues,
* which is why we're disabling it.
*/
options |= SSL_OP_NO_COMPRESSION;
/**
* SSL_OP_TLS_BLOCK_PADDING_BUG:
*
* The Microsoft RDP server does *not* support TLS padding.
* It absolutely needs to be disabled otherwise it won't work.
*/
options |= SSL_OP_TLS_BLOCK_PADDING_BUG;
/**
* SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS:
*
* Just like TLS padding, the Microsoft RDP server does not
* support empty fragments. This needs to be disabled.
*/
options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
self->ctx = SSL_CTX_new(SSLv23_server_method());
/* set context options */
SSL_CTX_set_mode(self->ctx,
SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER |
SSL_MODE_ENABLE_PARTIAL_WRITE);
SSL_CTX_set_options(self->ctx, options);
SSL_CTX_set_read_ahead(self->ctx, 1);
if (self->ctx == NULL)
{
g_writeln("xrdp_tls_accept: SSL_CTX_new failed");
return 1;
}
if (SSL_CTX_use_RSAPrivateKey_file(self->ctx, self->key, SSL_FILETYPE_PEM)
<= 0)
{
g_writeln("xrdp_tls_accept: SSL_CTX_use_RSAPrivateKey_file failed");
return 1;
}
self->ssl = SSL_new(self->ctx);
if (self->ssl == NULL)
{
g_writeln("xrdp_tls_accept: SSL_new failed");
return 1;
}
if (SSL_use_certificate_file(self->ssl, self->cert, SSL_FILETYPE_PEM) <= 0)
{
g_writeln("xrdp_tls_accept: SSL_use_certificate_file failed");
return 1;
}
if (SSL_set_fd(self->ssl, self->trans->sck) < 1)
{
g_writeln("xrdp_tls_accept: SSL_set_fd failed");
return 1;
}
connection_status = SSL_accept(self->ssl);
if (connection_status <= 0)
{
if (xrdp_tls_print_error("SSL_accept", self->ssl, connection_status))
{
return 1;
}
}
g_writeln("xrdp_tls_accept: TLS connection accepted");
return 0;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_print_error(char *func, SSL *connection, int value)
{
switch (SSL_get_error(connection, value))
{
case SSL_ERROR_ZERO_RETURN:
g_writeln("xrdp_tls_print_error: %s: Server closed TLS connection",
func);
return 1;
case SSL_ERROR_WANT_READ:
g_writeln("xrdp_tls_print_error: SSL_ERROR_WANT_READ");
return 0;
case SSL_ERROR_WANT_WRITE:
g_writeln("xrdp_tls_print_error: SSL_ERROR_WANT_WRITE");
return 0;
case SSL_ERROR_SYSCALL:
g_writeln("xrdp_tls_print_error: %s: I/O error", func);
return 1;
case SSL_ERROR_SSL:
g_writeln(
"xrdp_tls_print_error: %s: Failure in SSL library (protocol error?)",
func);
return 1;
default:
g_writeln("xrdp_tls_print_error: %s: Unknown error", func);
return 1;
}
}
/*****************************************************************************/
int APP_CC
xrdp_tls_disconnect(struct xrdp_tls *self)
{
int status = SSL_shutdown(self->ssl);
while (status != 1)
{
status = SSL_shutdown(self->ssl);
if (status <= 0)
{
if (xrdp_tls_print_error("SSL_shutdown", self->ssl, status))
{
return 1;
}
}
}
return 0;
}
/*****************************************************************************/
void APP_CC
xrdp_tls_delete(struct xrdp_tls *self)
{
if (self != NULL)
{
if (self->ssl)
SSL_free(self->ssl);
if (self->ctx)
SSL_CTX_free(self->ctx);
g_free(self);
}
}
/*****************************************************************************/
int APP_CC
xrdp_tls_read(struct xrdp_tls *tls, unsigned char *data, int length)
{
int status;
status = SSL_read(tls->ssl, data, length);
switch (SSL_get_error(tls->ssl, status))
{
case SSL_ERROR_NONE:
break;
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
status = 0;
break;
default:
xrdp_tls_print_error("SSL_read", tls->ssl, status);
status = -1;
break;
}
return status;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_write(struct xrdp_tls *tls, unsigned char *data, int length)
{
int status;
status = SSL_write(tls->ssl, data, length);
switch (SSL_get_error(tls->ssl, status))
{
case SSL_ERROR_NONE:
break;
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
status = 0;
break;
default:
xrdp_tls_print_error("SSL_write", tls->ssl, status);
status = -1;
break;
}
return status;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_force_read_s(struct trans *self, struct stream *in_s, int size)
{
int rcvd;
if (self->status != TRANS_STATUS_UP)
{
return 1;
}
while (size > 0)
{
/* make sure stream has room */
if ((in_s->end + size) > (in_s->data + in_s->size))
{
return 1;
}
rcvd = xrdp_tls_read(self->tls, in_s->end, size);
if (rcvd == -1)
{
if (g_tcp_last_error_would_block(self->sck))
{
if (!g_tcp_can_recv(self->sck, 100))
{
/* check for term here */
if (self->is_term != 0)
{
if (self->is_term())
{
/* term */
self->status = TRANS_STATUS_DOWN;
return 1;
}
}
}
}
else
{
/* error */
self->status = TRANS_STATUS_DOWN;
return 1;
}
}
else if (rcvd == 0)
{
/* error */
self->status = TRANS_STATUS_DOWN;
return 1;
}
else
{
in_s->end += rcvd;
size -= rcvd;
}
}
return 0;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_force_write_s(struct trans *self, struct stream *out_s)
{
int size;
int total;
int sent;
if (self->status != TRANS_STATUS_UP)
{
return 1;
}
size = (int) (out_s->end - out_s->data);
total = 0;
if (xrdp_tls_send_waiting(self, 1) != 0)
{
self->status = TRANS_STATUS_DOWN;
return 1;
}
while (total < size)
{
sent = xrdp_tls_write(self->tls, out_s->data + total, size - total);
if (sent == -1)
{
if (g_tcp_last_error_would_block(self->sck))
{
if (!g_tcp_can_send(self->sck, 100))
{
/* check for term here */
if (self->is_term != 0)
{
if (self->is_term())
{
/* term */
self->status = TRANS_STATUS_DOWN;
return 1;
}
}
}
}
else
{
/* error */
self->status = TRANS_STATUS_DOWN;
return 1;
}
}
else if (sent == 0)
{
/* error */
self->status = TRANS_STATUS_DOWN;
return 1;
}
else
{
total = total + sent;
}
}
return 0;
}
/*****************************************************************************/
int APP_CC
xrdp_tls_send_waiting(struct trans *self, int block)
{
struct stream *temp_s;
int bytes;
int sent;
int timeout;
int cont;
timeout = block ? 100 : 0;
cont = 1;
while (cont)
{
if (self->wait_s != 0)
{
temp_s = self->wait_s;
if (g_tcp_can_send(self->sck, timeout))
{
bytes = (int) (temp_s->end - temp_s->p);
sent = xrdp_tls_write(self->tls, temp_s->p, bytes);
if (sent > 0)
{
temp_s->p += sent;
if (temp_s->p >= temp_s->end)
{
self->wait_s = (struct stream *) (temp_s->next_packet);
free_stream(temp_s);
}
}
else if (sent == 0)
{
return 1;
}
else
{
if (!g_tcp_last_error_would_block(self->sck))
{
return 1;
}
}
}
}
else
{
break;
}
cont = block;
}
return 0;
}