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libvncserver
Commit 1408866c authored by Gernot Tenchio's avatar Gernot Tenchio
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websockets: Initial HyBi support

parent 02651bac
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Showing with 395 additions and 54 deletions
libvncserver/rfbserver.c
View file @ 1408866c
......@@ -365,8 +365,6 @@ rfbNewTCPOrUDPClient(rfbScreenInfoPtr rfbScreen,
#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
cl->webSockets = FALSE;
cl->webSocketsBase64 = FALSE;
cl->dblen= 0;
cl->carrylen = 0;
#endif
#if defined(LIBVNCSERVER_HAVE_LIBZ) || defined(LIBVNCSERVER_HAVE_LIBPNG)
......
libvncserver/sockets.c
View file @ 1408866c
......@@ -647,11 +647,12 @@ rfbWriteExact(rfbClientPtr cl,
#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
if (cl->webSockets) {
if ((len = webSocketsEncode(cl, buf, len)) < 0) {
char *tmp = NULL;
if ((len = webSocketsEncode(cl, buf, len, &tmp)) < 0) {
rfbErr("WriteExact: WebSockets encode error\n");
return -1;
}
buf = cl->encodeBuf;
buf = tmp;
}
#endif
......
libvncserver/websockets.c
View file @ 1408866c
......@@ -32,12 +32,90 @@
#include <errno.h>
#include <md5.h>
#include <byteswap.h>
#include "rfbconfig.h"
#include "rfbssl.h"
#if defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && __BYTE_ORDER == __BIG_ENDIAN
#define WS_NTOH64(n) (n)
#define WS_NTOH32(n) (n)
#define WS_NTOH16(n) (n)
#define WS_HTON64(n) (n)
#define WS_HTON16(n) (n)
#else
#define WS_NTOH64(n) bswap_64(n)
#define WS_NTOH32(n) bswap_32(n)
#define WS_NTOH16(n) bswap_16(n)
#define WS_HTON64(n) bswap_64(n)
#define WS_HTON16(n) bswap_16(n)
#endif
#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3)
#define WSHLENMAX 14 /* 2 + sizeof(uint64_t) + sizeof(uint32_t) */
enum {
WEBSOCKETS_VERSION_HIXIE,
WEBSOCKETS_VERSION_HYBI
};
#include <sys/syscall.h>
static int gettid() {
return (int)syscall(SYS_gettid);
}
typedef struct ws_ctx_s {
char encodeBuf[B64LEN(UPDATE_BUF_SIZE) + WSHLENMAX]; /* base64 + maximum frame header length */
char decodeBuf[8192]; /* TODO: what makes sense? */
char readbuf[8192];
int readbufstart;
int readbuflen;
int dblen;
char carryBuf[3]; /* For base64 carry-over */
int carrylen;
int version;
} ws_ctx_t;
typedef union ws_mask_s {
char c[4];
uint32_t u;
} ws_mask_t;
typedef struct __attribute__ ((__packed__)) ws_header_s {
unsigned char b0;
unsigned char b1;
union {
struct __attribute__ ((__packed__)) {
uint16_t l16;
ws_mask_t m16;
};
struct __attribute__ ((__packed__)) {
uint64_t l64;
ws_mask_t m64;
};
ws_mask_t m;
};
} ws_header_t;
enum
{
WS_OPCODE_CONTINUATION = 0x0,
WS_OPCODE_TEXT_FRAME,
WS_OPCODE_BINARY_FRAME,
WS_OPCODE_CLOSE = 0x8,
WS_OPCODE_PING,
WS_OPCODE_PONG
};
#define FLASH_POLICY_RESPONSE "<cross-domain-policy><allow-access-from domain=\"*\" to-ports=\"*\" /></cross-domain-policy>\n"
#define SZ_FLASH_POLICY_RESPONSE 93
#define WEBSOCKETS_HANDSHAKE_RESPONSE "HTTP/1.1 101 Web Socket Protocol Handshake\r\n\
/*
* draft-ietf-hybi-thewebsocketprotocol-10
* 5.2.2. Sending the Server's Opening Handshake
*/
#define GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
#define SERVER_HANDSHAKE_HIXIE "HTTP/1.1 101 Web Socket Protocol Handshake\r\n\
Upgrade: WebSocket\r\n\
Connection: Upgrade\r\n\
%sWebSocket-Origin: %s\r\n\
......@@ -45,6 +123,14 @@ Connection: Upgrade\r\n\
%sWebSocket-Protocol: %s\r\n\
\r\n%s"
#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 WEBSOCKETS_CLIENT_CONNECT_WAIT_MS 100
#define WEBSOCKETS_CLIENT_SEND_WAIT_MS 100
#define WEBSOCKETS_MAX_HANDSHAKE_LEN 4096
......@@ -65,6 +151,24 @@ min (int a, int b) {
return a < b ? a : b;
}
#ifdef LIBVNCSERVER_WITH_CLIENT_GCRYPT
#else
#include <openssl/sha.h>
static void webSocketsGenSha1Key(char *target, int size, char *key)
{
SHA_CTX c;
unsigned char tmp[SHA_DIGEST_LENGTH];
SHA1_Init(&c);
SHA1_Update(&c, key, strlen(key));
SHA1_Update(&c, GUID, sizeof(GUID) - 1);
SHA1_Final(tmp, &c);
if (-1 == __b64_ntop(tmp, SHA_DIGEST_LENGTH, target, size))
rfbErr("b64_ntop failed\n");
}
#endif
/*
* rfbWebSocketsHandshake is called to handle new WebSockets connections
*/
......@@ -126,6 +230,9 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
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;
buf = (char *) malloc(WEBSOCKETS_MAX_HANDSHAKE_LEN);
if (!buf) {
......@@ -198,16 +305,28 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
key2 = line+20;
buf[len-2] = '\0';
/* rfbLog("Got key2: %s\n", key2); */
} else if ((strncasecmp("sec-websocket-protocol: ", line, min(llen,24))) == 0) {
/* 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); */
}
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;
}
}
if (!(path && host && origin)) {
if (!(path && host && (origin || sec_ws_origin))) {
rfbErr("webSocketsHandshake: incomplete client handshake\n");
free(response);
free(buf);
......@@ -228,27 +347,40 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
* by the client.
*/
if (!(key1 && key2 && key3)) {
rfbLog(" - WebSockets client version 75\n");
prefix[0] = '\0';
trailer[0] = '\0';
if (sec_ws_version) {
char accept[SHA_DIGEST_LENGTH * 3];
rfbLog(" - WebSockets client version hybi-%02d\n", sec_ws_version);
webSocketsGenSha1Key(accept, sizeof(accept), sec_ws_key);
len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
SERVER_HANDSHAKE_HYBI, accept, protocol);
} else {
rfbLog(" - WebSockets client version 76\n");
snprintf(prefix, 5, "Sec-");
webSocketsGenMd5(trailer, key1, key2, key3);
/* older hixie handshake, this could be removed if
* a final standard is established */
if (!(key1 && key2 && key3)) {
rfbLog(" - WebSockets client version hixie-75\n");
prefix[0] = '\0';
trailer[0] = '\0';
} else {
rfbLog(" - WebSockets client version hixie-76\n");
snprintf(prefix, 5, "Sec-");
webSocketsGenMd5(trailer, key1, key2, key3);
}
len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
SERVER_HANDSHAKE_HIXIE, prefix, origin, prefix, scheme,
host, path, prefix, protocol, trailer);
}
snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
WEBSOCKETS_HANDSHAKE_RESPONSE, prefix, origin, prefix, scheme,
host, path, prefix, protocol, trailer);
if (rfbWriteExact(cl, response, strlen(response)) < 0) {
if (rfbWriteExact(cl, response, len) < 0) {
rfbErr("webSocketsHandshake: failed sending WebSockets response\n");
free(response);
free(buf);
return FALSE;
}
/* rfbLog("webSocketsHandshake: handshake complete\n"); */
rfbLog("webSocketsHandshake: %s\n", response);
free(response);
free(buf);
cl->wsctx = (wsCtx *)calloc(1, sizeof(ws_ctx_t));
((ws_ctx_t *)cl->wsctx)->version = sec_ws_version ? WEBSOCKETS_VERSION_HYBI : WEBSOCKETS_VERSION_HIXIE;
return TRUE;
}
......@@ -299,13 +431,15 @@ webSocketsGenMd5(char * target, char *key1, char *key2, char *key3)
}
int
webSocketsEncode(rfbClientPtr cl, const char *src, int len)
webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst)
{
int i, sz = 0;
unsigned char chr;
cl->encodeBuf[sz++] = '\x00';
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
wsctx->encodeBuf[sz++] = '\x00';
if (cl->webSocketsBase64) {
len = __b64_ntop((unsigned char *)src, len, cl->encodeBuf+sz, UPDATE_BUF_SIZE*2);
len = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf+sz, sizeof(wsctx->encodeBuf) - (sz + 1));
if (len < 0) {
return len;
}
......@@ -315,24 +449,24 @@ webSocketsEncode(rfbClientPtr cl, const char *src, int len)
chr = src[i];
if (chr < 128) {
if (chr == 0x00) {
cl->encodeBuf[sz++] = '\xc4';
cl->encodeBuf[sz++] = '\x80';
wsctx->encodeBuf[sz++] = '\xc4';
wsctx->encodeBuf[sz++] = '\x80';
} else {
cl->encodeBuf[sz++] = chr;
wsctx->encodeBuf[sz++] = chr;
}
} else {
if (chr < 192) {
cl->encodeBuf[sz++] = '\xc2';
cl->encodeBuf[sz++] = chr;
wsctx->encodeBuf[sz++] = '\xc2';
wsctx->encodeBuf[sz++] = chr;
} else {
cl->encodeBuf[sz++] = '\xc3';
cl->encodeBuf[sz++] = chr - 64;
wsctx->encodeBuf[sz++] = '\xc3';
wsctx->encodeBuf[sz++] = chr - 64;
}
}
}
}
cl->encodeBuf[sz++] = '\xff';
/* rfbLog("<< webSocketsEncode: %d\n", len); */
wsctx->encodeBuf[sz++] = '\xff';
*dst = wsctx->encodeBuf;
return sz;
}
......@@ -361,18 +495,19 @@ ws_peek(rfbClientPtr cl, char *buf, int len)
}
int
webSocketsDecode(rfbClientPtr cl, char *dst, int len)
webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len)
{
int retlen = 0, n, i, avail, modlen, needlen, actual;
char *buf, *end = NULL;
unsigned char chr, chr2;
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
buf = cl->decodeBuf;
buf = wsctx->decodeBuf;
n = ws_peek(cl, buf, len*2+2);
if (n <= 0) {
rfbErr("%s: recv of %d\n", __func__, n);
rfbErr("%s: peek of %d\n", __func__, n);
return n;
}
......@@ -406,7 +541,7 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len)
}
avail = end - buf;
len -= cl->carrylen;
len -= wsctx->carrylen;
/* Determine how much base64 data we need */
modlen = len + (len+2)/3;
......@@ -422,9 +557,9 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len)
}
/* Any carryover from previous decode */
for (i=0; i < cl->carrylen; i++) {
/* rfbLog("Adding carryover %d\n", cl->carryBuf[i]); */
dst[i] = cl->carryBuf[i];
for (i=0; i < wsctx->carrylen; i++) {
/* rfbLog("Adding carryover %d\n", wsctx->carryBuf[i]); */
dst[i] = wsctx->carryBuf[i];
retlen += 1;
}
......@@ -442,11 +577,11 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len)
/* Consume the data from socket */
i = ws_read(cl, buf, needlen);
cl->carrylen = n - len;
retlen -= cl->carrylen;
for (i=0; i < cl->carrylen; i++) {
wsctx->carrylen = n - len;
retlen -= wsctx->carrylen;
for (i=0; i < wsctx->carrylen; i++) {
/* rfbLog("Saving carryover %d\n", dst[retlen + i]); */
cl->carryBuf[i] = dst[retlen + i];
wsctx->carryBuf[i] = dst[retlen + i];
}
} else {
/* UTF-8 encoded WebSockets stream */
......@@ -509,3 +644,216 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len)
/* rfbLog("<< webSocketsDecode, retlen: %d\n", retlen); */
return retlen;
}
int
webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len)
{
char *buf, *payload, *rbuf;
int ret = -1, result = -1;
int total = 0;
ws_mask_t mask;
ws_header_t *header;
int i, j;
unsigned char opcode;
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
int flength, fin, fhlen, blen;
// rfbLog(" <== %s[%d]: %d cl: %p, wsctx: %p-%p (%d)\n", __func__, gettid(), len, cl, wsctx, (char *)wsctx + sizeof(ws_ctx_t), sizeof(ws_ctx_t));
if (wsctx->readbuflen) {
/* simply return what we have */
if (wsctx->readbuflen > len) {
memcpy(dst, wsctx->readbuf + wsctx->readbufstart, len);
result = len;
wsctx->readbuflen -= len;
wsctx->readbufstart += len;
} else {
memcpy(dst, wsctx->readbuf + wsctx->readbufstart, wsctx->readbuflen);
result = wsctx->readbuflen;
wsctx->readbuflen = 0;
wsctx->readbufstart = 0;
}
goto spor;
}
buf = wsctx->decodeBuf;
header = (ws_header_t *)wsctx->decodeBuf;
if (-1 == (ret = ws_peek(cl, buf, B64LEN(len) + WSHLENMAX))) {
rfbErr("%s: peek; %m\n", __func__);
goto spor;
}
if (ret < 2) {
rfbErr("%s: peek; got %d bytes\n", __func__, ret);
goto spor; /* Incomplete frame header */
}
opcode = header->b0 & 0x0f;
fin = (header->b0 & 0x80) >> 7;
flength = header->b1 & 0x7f;
/*
* 4.3. Client-to-Server Masking
*
* The client MUST mask all frames sent to the server. A server MUST
* close the connection upon receiving a frame with the MASK bit set to 0.
**/
if (!(header->b1 & 0x80)) {
rfbErr("%s: got frame without mask\n", __func__, ret);
errno = EIO;
goto spor;
}
if (flength < 126) {
fhlen = 2;
mask = header->m;
} else if (flength == 126 && 4 <= ret) {
flength = WS_NTOH16(header->l16);
fhlen = 4;
mask = header->m16;
} else if (flength == 127 && 10 <= ret) {
flength = WS_NTOH64(header->l64);
fhlen = 10;
mask = header->m64;
} else {
/* Incomplete frame header */
rfbErr("%s: incomplete frame header\n", __func__, ret);
errno = EIO;
goto spor;
}
/* absolute length of frame */
total = fhlen + flength + 4;
payload = buf + fhlen + 4; /* header length + mask */
if (-1 == (ret = ws_read(cl, buf, total))) {
rfbErr("%s: read; %m", __func__);
return ret;
} else if (ret < total) {
/* TODO: hmm? */
rfbLog("%s: read; got partial data\n", __func__);
} else {
buf[ret] = '\0';
}
/* process 1 frame */
for (i = 0; i < flength; i++) {
j = i % 4;
payload[i] ^= mask.c[j];
}
switch (opcode) {
case WS_OPCODE_CLOSE:
rfbLog("got closure, reason %d\n", WS_NTOH16(((uint16_t *)payload)[0]));
errno = ECONNRESET;
break;
case WS_OPCODE_TEXT_FRAME:
if (-1 == (flength = __b64_pton(payload, (unsigned char *)wsctx->decodeBuf, sizeof(wsctx->decodeBuf)))) {
rfbErr("%s: Base64 decode error; %m\n", __func__);
break;
}
payload = wsctx->decodeBuf;
/* fall through */
case WS_OPCODE_BINARY_FRAME:
if (flength > len) {
memcpy(wsctx->readbuf, payload + len, flength - len);
wsctx->readbufstart = 0;
wsctx->readbuflen = flength - len;
flength = len;
}
memcpy(dst, payload, flength);
result = flength;
break;
default:
rfbErr("unhandled opcode %d, b0: %02x, b1: %02x\n", (int)opcode, header->b0, header->b1);
}
/* single point of return, if someone has questions :-) */
spor:
/* rfbLog("%s: ret: %d/%d\n", __func__, result, len); */
return result;
}
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) {
rfbLog("%s: nothing to encode\n", __func__);
return 0;
}
header = (ws_header_t *)wsctx->encodeBuf;
if (cl->webSocketsBase64) {
opcode = WS_OPCODE_TEXT_FRAME;
/* calculate the resulting size */
blen = B64LEN(len);
} else {
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->l16 = WS_HTON16((uint16_t)blen);
sz = 4;
} else {
header->b1 = 0x7f;
header->l64 = WS_HTON64(blen);
sz = 10;
}
if (cl->webSocketsBase64) {
if (-1 == (ret = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf + sz, sizeof(wsctx->encodeBuf) - 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->encodeBuf + sz, src, len);
ret = sz + len;
}
*dst = wsctx->encodeBuf;
return ret;
}
int
webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst)
{
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
if (wsctx->version == WEBSOCKETS_VERSION_HIXIE)
return webSocketsEncodeHixie(cl, src, len, dst);
else
return webSocketsEncodeHybi(cl, src, len, dst);
}
int
webSocketsDecode(rfbClientPtr cl, char *dst, int len)
{
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
if (wsctx->version == WEBSOCKETS_VERSION_HIXIE)
return webSocketsDecodeHixie(cl, dst, len);
else
return webSocketsDecodeHybi(cl, dst, len);
}
rfb/rfb.h
View file @ 1408866c
......@@ -419,6 +419,7 @@ typedef struct _rfbStatList {
} rfbStatList;
typedef struct _rfbSslCtx rfbSslCtx;
typedef struct _wsCtx wsCtx;
typedef struct _rfbClientRec {
......@@ -640,17 +641,10 @@ typedef struct _rfbClientRec {
#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
rfbBool webSockets;
rfbBool webSocketsSSL;
rfbBool webSocketsBase64;
rfbSslCtx *sslctx;
wsCtx *wsctx;
char *wspath; /* Requests path component */
char encodeBuf[UPDATE_BUF_SIZE*2 + 2]; /* UTF-8 could double it + framing */
char decodeBuf[8192]; /* TODO: what makes sense? */
int dblen;
char carryBuf[3]; /* For base64 carry-over */
int carrylen;
#endif
} rfbClientRec, *rfbClientPtr;
......@@ -718,7 +712,7 @@ extern rfbBool rfbSetNonBlocking(int sock);
/* websockets.c */
extern rfbBool webSocketsCheck(rfbClientPtr cl);
extern int webSocketsEncode(rfbClientPtr cl, const char *src, int len);
extern int webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst);
extern int webSocketsDecode(rfbClientPtr cl, char *dst, int len);
#endif
......
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