Malicious RDP server security fixes

This commit includes fixes for a set of 21 vulnerabilities in
rdesktop when a malicious RDP server is used.

All vulnerabilities was identified and reported by Eyal Itkin.

 * Add rdp_protocol_error function that is used in several fixes
 * Refactor of process_bitmap_updates
 * Fix possible integer overflow in s_check_rem() on 32bit arch
 * Fix memory corruption in process_bitmap_data - CVE-2018-8794
 * Fix remote code execution in process_bitmap_data - CVE-2018-8795
 * Fix remote code execution in process_plane - CVE-2018-8797
 * Fix Denial of Service in mcs_recv_connect_response - CVE-2018-20175
 * Fix Denial of Service in mcs_parse_domain_params - CVE-2018-20175
 * Fix Denial of Service in sec_parse_crypt_info - CVE-2018-20176
 * Fix Denial of Service in sec_recv - CVE-2018-20176
 * Fix minor information leak in rdpdr_process - CVE-2018-8791
 * Fix Denial of Service in cssp_read_tsrequest - CVE-2018-8792
 * Fix remote code execution in cssp_read_tsrequest - CVE-2018-8793
 * Fix Denial of Service in process_bitmap_data - CVE-2018-8796
 * Fix minor information leak in rdpsnd_process_ping - CVE-2018-8798
 * Fix Denial of Service in process_secondary_order - CVE-2018-8799
 * Fix remote code execution in in ui_clip_handle_data - CVE-2018-8800
 * Fix major information leak in ui_clip_handle_data - CVE-2018-20174
 * Fix memory corruption in rdp_in_unistr - CVE-2018-20177
 * Fix Denial of Service in process_demand_active - CVE-2018-20178
 * Fix remote code execution in lspci_process - CVE-2018-20179
 * Fix remote code execution in rdpsnddbg_process - CVE-2018-20180
 * Fix remote code execution in seamless_process - CVE-2018-20181
 * Fix remote code execution in seamless_process_line - CVE-2018-20182
setup_brush(BRUSH * out_brush, BRUSH * in_brush)
{
	BRUSHDATA *brush_data;
	uint8 cache_idx;
	uint8 colour_code;

	memcpy(out_brush, in_brush, sizeof(BRUSH));
	if (out_brush->style & 0x80)
	{
		colour_code = out_brush->style & 0x0f;
		cache_idx = out_brush->pattern[0];
		brush_data = cache_get_brush_data(colour_code, cache_idx);
		if ((brush_data == NULL) || (brush_data->data == NULL))
		{
			logger(Graphics, Error, "setup_brush(), error getting brush data, style %x",
			       out_brush->style);
			out_brush->bd = NULL;
			memset(out_brush->pattern, 0, 8);
		}
		else
		{
			out_brush->bd = brush_data;
		}
		out_brush->style = 3;
	}
}

setup_brush(BRUSH * out_brush, BRUSH * in_brush)
{
	BRUSHDATA *brush_data;
	uint8 cache_idx;
	uint8 colour_code;

	memcpy(out_brush, in_brush, sizeof(BRUSH));
	if (out_brush->style & 0x80)
	{
		colour_code = out_brush->style & 0x0f;
		cache_idx = out_brush->pattern[0];
		brush_data = cache_get_brush_data(colour_code, cache_idx);
		if ((brush_data == NULL) || (brush_data->data == NULL))
		{
			logger(Graphics, Error, "setup_brush(), error getting brush data, style %x",
			       out_brush->style);
			out_brush->bd = NULL;
			memset(out_brush->pattern, 0, 8);
		}
		else
		{
			out_brush->bd = brush_data;
		}
		out_brush->style = 3;
	}
}
