You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
459 lines
13 KiB
459 lines
13 KiB
/*
|
|
* websockets.c - deal with WebSockets clients.
|
|
*
|
|
* This code should be independent of any changes in the RFB protocol. It is
|
|
* an additional handshake and framing of normal sockets:
|
|
* http://www.whatwg.org/specs/web-socket-protocol/
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2010 Joel Martin
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <rfb/rfb.h>
|
|
/* errno */
|
|
#include <errno.h>
|
|
|
|
#ifdef LIBVNCSERVER_HAVE_ENDIAN_H
|
|
#include <endian.h>
|
|
#elif LIBVNCSERVER_HAVE_SYS_ENDIAN_H
|
|
#include <sys/endian.h>
|
|
#endif
|
|
|
|
#ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
|
|
#include <sys/types.h>
|
|
#endif
|
|
|
|
#include <string.h>
|
|
#if LIBVNCSERVER_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
#include "rfb/rfbconfig.h"
|
|
#include "rfbssl.h"
|
|
#include "rfbcrypto.h"
|
|
#include "ws_decode.h"
|
|
#include "base64.h"
|
|
|
|
#if 0
|
|
#include <sys/syscall.h>
|
|
static int gettid() {
|
|
return (int)syscall(SYS_gettid);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* draft-ietf-hybi-thewebsocketprotocol-10
|
|
* 5.2.2. Sending the Server's Opening Handshake
|
|
*/
|
|
#define GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
|
|
|
|
#define SERVER_HANDSHAKE_HYBI "HTTP/1.1 101 Switching Protocols\r\n\
|
|
Upgrade: websocket\r\n\
|
|
Connection: Upgrade\r\n\
|
|
Sec-WebSocket-Accept: %s\r\n\
|
|
Sec-WebSocket-Protocol: %s\r\n\
|
|
\r\n"
|
|
|
|
#define SERVER_HANDSHAKE_HYBI_NO_PROTOCOL "HTTP/1.1 101 Switching Protocols\r\n\
|
|
Upgrade: websocket\r\n\
|
|
Connection: Upgrade\r\n\
|
|
Sec-WebSocket-Accept: %s\r\n\
|
|
\r\n"
|
|
|
|
#define WEBSOCKETS_CLIENT_CONNECT_WAIT_MS 100
|
|
#define WEBSOCKETS_CLIENT_SEND_WAIT_MS 100
|
|
#define WEBSOCKETS_MAX_HANDSHAKE_LEN 4096
|
|
|
|
#if defined(__linux__) && defined(NEED_TIMEVAL)
|
|
struct timeval
|
|
{
|
|
long int tv_sec,tv_usec;
|
|
}
|
|
;
|
|
#endif
|
|
|
|
static rfbBool webSocketsHandshake(rfbClientPtr cl, char *scheme);
|
|
|
|
static int webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst);
|
|
|
|
static int ws_read(void *cl, char *buf, size_t len);
|
|
|
|
|
|
static int
|
|
min (int a, int b) {
|
|
return a < b ? a : b;
|
|
}
|
|
|
|
static void webSocketsGenSha1Key(char *target, int size, char *key)
|
|
{
|
|
struct iovec iov[2];
|
|
unsigned char hash[20];
|
|
|
|
iov[0].iov_base = key;
|
|
iov[0].iov_len = strlen(key);
|
|
iov[1].iov_base = GUID;
|
|
iov[1].iov_len = sizeof(GUID) - 1;
|
|
digestsha1(iov, 2, hash);
|
|
if (-1 == rfbBase64NtoP(hash, sizeof(hash), target, size))
|
|
rfbErr("rfbBase64NtoP failed\n");
|
|
}
|
|
|
|
/*
|
|
* rfbWebSocketsHandshake is called to handle new WebSockets connections
|
|
*/
|
|
|
|
rfbBool
|
|
webSocketsCheck (rfbClientPtr cl)
|
|
{
|
|
char bbuf[4], *scheme;
|
|
int ret;
|
|
|
|
ret = rfbPeekExactTimeout(cl, bbuf, 4,
|
|
WEBSOCKETS_CLIENT_CONNECT_WAIT_MS);
|
|
if ((ret < 0) && (errno == ETIMEDOUT)) {
|
|
rfbLog("Normal socket connection\n");
|
|
return TRUE;
|
|
} else if (ret <= 0) {
|
|
rfbErr("webSocketsHandshake: unknown connection error\n");
|
|
return FALSE;
|
|
}
|
|
|
|
if (strncmp(bbuf, "RFB ", 4) == 0) {
|
|
rfbLog("Normal socket connection\n");
|
|
return TRUE;
|
|
} else if (strncmp(bbuf, "\x16", 1) == 0 || strncmp(bbuf, "\x80", 1) == 0) {
|
|
rfbLog("Got TLS/SSL WebSockets connection\n");
|
|
if (-1 == rfbssl_init(cl)) {
|
|
rfbErr("webSocketsHandshake: rfbssl_init failed\n");
|
|
return FALSE;
|
|
}
|
|
ret = rfbPeekExactTimeout(cl, bbuf, 4, WEBSOCKETS_CLIENT_CONNECT_WAIT_MS);
|
|
scheme = "wss";
|
|
} else {
|
|
scheme = "ws";
|
|
}
|
|
|
|
if (strncmp(bbuf, "GET ", 4) != 0) {
|
|
rfbErr("webSocketsHandshake: invalid client header\n");
|
|
return FALSE;
|
|
}
|
|
|
|
rfbLog("Got '%s' WebSockets handshake\n", scheme);
|
|
|
|
if (!webSocketsHandshake(cl, scheme)) {
|
|
return FALSE;
|
|
}
|
|
/* Start WebSockets framing */
|
|
return TRUE;
|
|
}
|
|
|
|
static rfbBool
|
|
webSocketsHandshake(rfbClientPtr cl, char *scheme)
|
|
{
|
|
char *buf, *response, *line;
|
|
int n, linestart = 0, len = 0, llen, base64 = TRUE;
|
|
char prefix[5], trailer[17];
|
|
char *path = NULL, *host = NULL, *origin = NULL, *protocol = NULL;
|
|
char *key1 = NULL, *key2 = NULL, *key3 = NULL;
|
|
char *sec_ws_origin = NULL;
|
|
char *sec_ws_key = NULL;
|
|
char sec_ws_version = 0;
|
|
ws_ctx_t *wsctx = NULL;
|
|
|
|
buf = (char *) malloc(WEBSOCKETS_MAX_HANDSHAKE_LEN);
|
|
if (!buf) {
|
|
rfbLogPerror("webSocketsHandshake: malloc");
|
|
return FALSE;
|
|
}
|
|
response = (char *) malloc(WEBSOCKETS_MAX_HANDSHAKE_LEN);
|
|
if (!response) {
|
|
free(buf);
|
|
rfbLogPerror("webSocketsHandshake: malloc");
|
|
return FALSE;
|
|
}
|
|
|
|
while (len < WEBSOCKETS_MAX_HANDSHAKE_LEN-1) {
|
|
if ((n = rfbReadExactTimeout(cl, buf+len, 1,
|
|
WEBSOCKETS_CLIENT_SEND_WAIT_MS)) <= 0) {
|
|
if ((n < 0) && (errno == ETIMEDOUT)) {
|
|
break;
|
|
}
|
|
if (n == 0) {
|
|
rfbLog("webSocketsHandshake: client gone\n");
|
|
}
|
|
else {
|
|
rfbLogPerror("webSocketsHandshake: read");
|
|
}
|
|
|
|
free(response);
|
|
free(buf);
|
|
return FALSE;
|
|
}
|
|
|
|
len += 1;
|
|
llen = len - linestart;
|
|
if (((llen >= 2)) && (buf[len-1] == '\n')) {
|
|
line = buf+linestart;
|
|
if ((llen == 2) && (strncmp("\r\n", line, 2) == 0)) {
|
|
if (key1 && key2) {
|
|
if ((n = rfbReadExact(cl, buf+len, 8)) <= 0) {
|
|
if ((n < 0) && (errno == ETIMEDOUT)) {
|
|
break;
|
|
}
|
|
if (n == 0)
|
|
rfbLog("webSocketsHandshake: client gone\n");
|
|
else
|
|
rfbLogPerror("webSocketsHandshake: read");
|
|
free(response);
|
|
free(buf);
|
|
return FALSE;
|
|
}
|
|
rfbLog("Got key3\n");
|
|
key3 = buf+len;
|
|
len += 8;
|
|
} else {
|
|
buf[len] = '\0';
|
|
}
|
|
break;
|
|
} else if ((llen >= 16) && ((strncmp("GET ", line, min(llen,4))) == 0)) {
|
|
/* 16 = 4 ("GET ") + 1 ("/.*") + 11 (" HTTP/1.1\r\n") */
|
|
path = line+4;
|
|
buf[len-11] = '\0'; /* Trim trailing " HTTP/1.1\r\n" */
|
|
cl->wspath = strdup(path);
|
|
/* rfbLog("Got path: %s\n", path); */
|
|
} else if ((strncasecmp("host: ", line, min(llen,6))) == 0) {
|
|
host = line+6;
|
|
buf[len-2] = '\0';
|
|
/* rfbLog("Got host: %s\n", host); */
|
|
} else if ((strncasecmp("origin: ", line, min(llen,8))) == 0) {
|
|
origin = line+8;
|
|
buf[len-2] = '\0';
|
|
/* rfbLog("Got origin: %s\n", origin); */
|
|
} else if ((strncasecmp("sec-websocket-key1: ", line, min(llen,20))) == 0) {
|
|
key1 = line+20;
|
|
buf[len-2] = '\0';
|
|
/* rfbLog("Got key1: %s\n", key1); */
|
|
} else if ((strncasecmp("sec-websocket-key2: ", line, min(llen,20))) == 0) {
|
|
key2 = line+20;
|
|
buf[len-2] = '\0';
|
|
/* rfbLog("Got key2: %s\n", key2); */
|
|
/* HyBI */
|
|
|
|
} else if ((strncasecmp("sec-websocket-protocol: ", line, min(llen,24))) == 0) {
|
|
protocol = line+24;
|
|
buf[len-2] = '\0';
|
|
rfbLog("Got protocol: %s\n", protocol);
|
|
} else if ((strncasecmp("sec-websocket-origin: ", line, min(llen,22))) == 0) {
|
|
sec_ws_origin = line+22;
|
|
buf[len-2] = '\0';
|
|
} else if ((strncasecmp("sec-websocket-key: ", line, min(llen,19))) == 0) {
|
|
sec_ws_key = line+19;
|
|
buf[len-2] = '\0';
|
|
} else if ((strncasecmp("sec-websocket-version: ", line, min(llen,23))) == 0) {
|
|
sec_ws_version = strtol(line+23, NULL, 10);
|
|
buf[len-2] = '\0';
|
|
}
|
|
|
|
linestart = len;
|
|
}
|
|
}
|
|
|
|
/* older hixie handshake, this could be removed if
|
|
* a final standard is established -- removed now */
|
|
if (!sec_ws_version) {
|
|
rfbErr("Hixie no longer supported\n");
|
|
free(response);
|
|
free(buf);
|
|
return FALSE;
|
|
}
|
|
|
|
if (!(path && host && (origin || sec_ws_origin))) {
|
|
rfbErr("webSocketsHandshake: incomplete client handshake\n");
|
|
free(response);
|
|
free(buf);
|
|
return FALSE;
|
|
}
|
|
|
|
if ((protocol) && (strstr(protocol, "binary"))) {
|
|
rfbLog(" - webSocketsHandshake: using binary/raw encoding\n");
|
|
base64 = FALSE;
|
|
protocol = "binary";
|
|
} else {
|
|
rfbLog(" - webSocketsHandshake: using base64 encoding\n");
|
|
base64 = TRUE;
|
|
if ((protocol) && (strstr(protocol, "base64"))) {
|
|
protocol = "base64";
|
|
} else {
|
|
protocol = "";
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Generate the WebSockets server response based on the the headers sent
|
|
* by the client.
|
|
*/
|
|
char accept[B64LEN(SHA1_HASH_SIZE) + 1];
|
|
rfbLog(" - WebSockets client version hybi-%02d\n", sec_ws_version);
|
|
webSocketsGenSha1Key(accept, sizeof(accept), sec_ws_key);
|
|
|
|
if(strlen(protocol) > 0) {
|
|
len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
|
|
SERVER_HANDSHAKE_HYBI, accept, protocol);
|
|
} else {
|
|
len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
|
|
SERVER_HANDSHAKE_HYBI_NO_PROTOCOL, accept);
|
|
}
|
|
|
|
if (rfbWriteExact(cl, response, len) < 0) {
|
|
rfbErr("webSocketsHandshake: failed sending WebSockets response\n");
|
|
free(response);
|
|
free(buf);
|
|
return FALSE;
|
|
}
|
|
/* rfbLog("webSocketsHandshake: %s\n", response); */
|
|
free(response);
|
|
free(buf);
|
|
|
|
wsctx = calloc(1, sizeof(ws_ctx_t));
|
|
wsctx->encode = webSocketsEncodeHybi;
|
|
wsctx->decode = webSocketsDecodeHybi;
|
|
wsctx->ctxInfo.readFunc = ws_read;
|
|
wsctx->base64 = base64;
|
|
hybiDecodeCleanupComplete(wsctx);
|
|
cl->wsctx = (wsCtx *)wsctx;
|
|
return TRUE;
|
|
}
|
|
|
|
static int
|
|
ws_read(void *ctxPtr, char *buf, size_t len)
|
|
{
|
|
int n;
|
|
rfbClientPtr cl = ctxPtr;
|
|
if (cl->sslctx) {
|
|
n = rfbssl_read(cl, buf, len);
|
|
} else {
|
|
n = read(cl->sock, buf, len);
|
|
}
|
|
return n;
|
|
}
|
|
|
|
static int
|
|
webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst)
|
|
{
|
|
int blen, ret = -1, sz = 0;
|
|
unsigned char opcode = '\0'; /* TODO: option! */
|
|
ws_header_t *header;
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
|
|
|
|
/* Optional opcode:
|
|
* 0x0 - continuation
|
|
* 0x1 - text frame (base64 encode buf)
|
|
* 0x2 - binary frame (use raw buf)
|
|
* 0x8 - connection close
|
|
* 0x9 - ping
|
|
* 0xA - pong
|
|
**/
|
|
if (!len) {
|
|
/* nothing to encode */
|
|
return 0;
|
|
}
|
|
|
|
header = (ws_header_t *)wsctx->codeBufEncode;
|
|
|
|
if (wsctx->base64) {
|
|
opcode = WS_OPCODE_TEXT_FRAME;
|
|
/* calculate the resulting size */
|
|
blen = B64LEN(len);
|
|
} else {
|
|
opcode = WS_OPCODE_BINARY_FRAME;
|
|
blen = len;
|
|
}
|
|
|
|
header->b0 = 0x80 | (opcode & 0x0f);
|
|
if (blen <= 125) {
|
|
header->b1 = (uint8_t)blen;
|
|
sz = 2;
|
|
} else if (blen <= 65536) {
|
|
header->b1 = 0x7e;
|
|
header->u.s16.l16 = WS_HTON16((uint16_t)blen);
|
|
sz = 4;
|
|
} else {
|
|
header->b1 = 0x7f;
|
|
header->u.s64.l64 = WS_HTON64(blen);
|
|
sz = 10;
|
|
}
|
|
|
|
if (wsctx->base64) {
|
|
if (-1 == (ret = rfbBase64NtoP((unsigned char *)src, len, wsctx->codeBufEncode + sz, sizeof(wsctx->codeBufEncode) - sz))) {
|
|
rfbErr("%s: Base 64 encode failed\n", __func__);
|
|
} else {
|
|
if (ret != blen)
|
|
rfbErr("%s: Base 64 encode; something weird happened\n", __func__);
|
|
ret += sz;
|
|
}
|
|
} else {
|
|
memcpy(wsctx->codeBufEncode + sz, src, len);
|
|
ret = sz + len;
|
|
}
|
|
|
|
*dst = wsctx->codeBufEncode;
|
|
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst)
|
|
{
|
|
return webSocketsEncodeHybi(cl, src, len, dst);
|
|
}
|
|
|
|
int
|
|
webSocketsDecode(rfbClientPtr cl, char *dst, int len)
|
|
{
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
wsctx->ctxInfo.ctxPtr = cl;
|
|
return webSocketsDecodeHybi(wsctx, dst, len);
|
|
}
|
|
|
|
/**
|
|
* This is a stub function that was once used for Hixie-encoding.
|
|
* We keep it for API compatibility.
|
|
*/
|
|
rfbBool
|
|
webSocketCheckDisconnect(rfbClientPtr cl)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
|
|
/* returns TRUE if there is data waiting to be read in our internal buffer
|
|
* or if is there any pending data in the buffer of the SSL implementation
|
|
*/
|
|
rfbBool
|
|
webSocketsHasDataInBuffer(rfbClientPtr cl)
|
|
{
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
|
|
if (wsctx && wsctx->readlen)
|
|
return TRUE;
|
|
|
|
return (cl->sslctx && rfbssl_pending(cl) > 0);
|
|
}
|