From 4aa35863676335917d2a25a7952031f0fba66dfb Mon Sep 17 00:00:00 2001 From: Gernot Tenchio Date: Tue, 16 Aug 2011 14:02:35 +0200 Subject: [PATCH] websockets: Add encryption support [jes: moved out GnuTLS and OpenSSL support, added a dummy support, to separate changes better, and to keep things compiling] Signed-off-by: Johannes Schindelin --- libvncserver/Makefile.am | 2 +- libvncserver/rfbserver.c | 55 ++++++++++++++++++++++++++++++------ libvncserver/rfbssl.h | 15 ++++++++++ libvncserver/rfbssl_none.c | 58 ++++++++++++++++++++++++++++++++++++++ libvncserver/sockets.c | 43 ++++++++++++++++++++++++---- libvncserver/websockets.c | 49 ++++++++++++++++++++++++-------- rfb/rfb.h | 9 +++++- 7 files changed, 204 insertions(+), 27 deletions(-) create mode 100644 libvncserver/rfbssl.h create mode 100644 libvncserver/rfbssl_none.c diff --git a/libvncserver/Makefile.am b/libvncserver/Makefile.am index 0d64363..bbc8feb 100644 --- a/libvncserver/Makefile.am +++ b/libvncserver/Makefile.am @@ -13,7 +13,7 @@ TIGHTVNCFILETRANSFERSRCS = tightvnc-filetransfer/rfbtightserver.c \ endif if WITH_WEBSOCKETS -WEBSOCKETSSRCS = websockets.c md5.c +WEBSOCKETSSRCS = websockets.c md5.c rfbssl_none.c endif includedir=$(prefix)/include/rfb diff --git a/libvncserver/rfbserver.c b/libvncserver/rfbserver.c index 25204cd..c623329 100644 --- a/libvncserver/rfbserver.c +++ b/libvncserver/rfbserver.c @@ -73,6 +73,10 @@ /* strftime() */ #include +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS +#include "rfbssl.h" +#endif + #ifdef __MINGW32__ static int compat_mkdir(const char *path, int mode) { @@ -360,7 +364,6 @@ rfbNewTCPOrUDPClient(rfbScreenInfoPtr rfbScreen, #ifdef LIBVNCSERVER_WITH_WEBSOCKETS cl->webSockets = FALSE; - cl->webSocketsSSL = FALSE; cl->webSocketsBase64 = FALSE; cl->dblen= 0; cl->carrylen = 0; @@ -1841,16 +1844,50 @@ rfbProcessClientNormalMessage(rfbClientPtr cl) #ifdef LIBVNCSERVER_WITH_WEBSOCKETS if (cl->webSockets) { - n = recv(cl->sock, encBuf, 4, MSG_PEEK); - if (cl->webSocketsBase64) { + if (cl->sslctx) + n = rfbssl_peek(cl, encBuf, 4); + else + n = recv(cl->sock, encBuf, 4, MSG_PEEK); + + if (n <= 0) { + if (n != 0) + rfbLogPerror("rfbProcessClientNormalMessage: peek"); + rfbCloseClient(cl); + return; + } + + if (cl->webSocketsBase64) { /* With Base64 encoding we need at least 4 bytes */ if ((n > 0) && (n < 4)) { if (encBuf[0] == '\xff') { + int doclose = 0; /* Make sure we don't miss a client disconnect on an end frame - * marker */ - n = read(cl->sock, encBuf, 1); + * marker. Because we use a peek buffer in some cases it is not + * applicable to wait for more data per select(). */ + switch (n) { + case 3: + if (encBuf[1] == '\xff' && encBuf[2] == '\x00') + doclose = 1; + break; + case 2: + if (encBuf[1] == '\x00') + doclose = 1; + break; + default: + ; + } + + if (cl->sslctx) + n = rfbssl_read(cl, encBuf, n); + else + n = read(cl->sock, encBuf, n); + + if (doclose) { + rfbErr("rfbProcessClientNormalMessage: websocket close frame received\n"); + rfbCloseClient(cl); + } + return; } - return; } } else { /* With UTF-8 encoding we need at least 3 bytes (framing + 1) */ @@ -1858,9 +1895,11 @@ rfbProcessClientNormalMessage(rfbClientPtr cl) if (encBuf[0] == '\xff') { /* Make sure we don't miss a client disconnect on an end frame * marker */ - n = read(cl->sock, encBuf, 1); + if (cl->sslctx) + n = rfbssl_read(cl, encBuf, 1); + else + n = read(cl->sock, encBuf, 1); } - return; } } } diff --git a/libvncserver/rfbssl.h b/libvncserver/rfbssl.h new file mode 100644 index 0000000..f1c4792 --- /dev/null +++ b/libvncserver/rfbssl.h @@ -0,0 +1,15 @@ +#ifndef _VNCSSL_H +#define _VNCSSL_H 1 + +#include "rfb/rfb.h" +#include "rfb/rfbconfig.h" + +int rfbssl_init(rfbClientPtr cl); +int rfbssl_pending(rfbClientPtr cl); +int rfbssl_peek(rfbClientPtr cl, char *buf, int bufsize); +int rfbssl_read(rfbClientPtr cl, char *buf, int bufsize); +int rfbssl_write(rfbClientPtr cl, const char *buf, int bufsize); +void rfbssl_destroy(rfbClientPtr cl); + + +#endif /* _VNCSSL_H */ diff --git a/libvncserver/rfbssl_none.c b/libvncserver/rfbssl_none.c new file mode 100644 index 0000000..488a6f4 --- /dev/null +++ b/libvncserver/rfbssl_none.c @@ -0,0 +1,58 @@ +/* + * rfbssl_none.c - Secure socket functions (fallback to failing) + */ + +/* + * Copyright (C) 2011 Johannes Schindelin + * + * 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 "rfbssl.h" + +struct rfbssl_ctx *rfbssl_init_global(char *key, char *cert) +{ + return NULL; +} + +int rfbssl_init(rfbClientPtr cl) +{ + return -1; +} + +int rfbssl_write(rfbClientPtr cl, const char *buf, int bufsize) +{ + return -1; +} + +int rfbssl_peek(rfbClientPtr cl, char *buf, int bufsize) +{ + return -1; +} + +int rfbssl_read(rfbClientPtr cl, char *buf, int bufsize) +{ + return -1; +} + +int rfbssl_pending(rfbClientPtr cl) +{ + return -1; +} + +void rfbssl_destroy(rfbClientPtr cl) +{ +} diff --git a/libvncserver/sockets.c b/libvncserver/sockets.c index 267287d..1886187 100644 --- a/libvncserver/sockets.c +++ b/libvncserver/sockets.c @@ -62,6 +62,10 @@ #include #endif +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS +#include "rfbssl.h" +#endif + #if defined(__linux__) && defined(NEED_TIMEVAL) struct timeval { @@ -392,6 +396,10 @@ rfbCloseClient(rfbClientPtr cl) while(cl->screen->maxFd>0 && !FD_ISSET(cl->screen->maxFd,&(cl->screen->allFds))) cl->screen->maxFd--; +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + if (cl->sslctx) + rfbssl_destroy(cl); +#endif #ifndef __MINGW32__ shutdown(cl->sock,SHUT_RDWR); #endif @@ -460,7 +468,9 @@ rfbReadExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) #ifdef LIBVNCSERVER_WITH_WEBSOCKETS if (cl->webSockets) { n = webSocketsDecode(cl, buf, len); - } else { + } else if (cl->sslctx) { + n = rfbssl_read(cl, buf, len); + } else { n = read(sock, buf, len); } #else @@ -490,6 +500,12 @@ rfbReadExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) return n; } +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + if (cl->sslctx) { + if (rfbssl_pending(cl)) + continue; + } +#endif FD_ZERO(&fds); FD_SET(sock, &fds); tv.tv_sec = timeout / 1000; @@ -500,6 +516,7 @@ rfbReadExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) return n; } if (n == 0) { + rfbErr("ReadExact: select timeout\n"); errno = ETIMEDOUT; return -1; } @@ -540,7 +557,12 @@ rfbPeekExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) struct timeval tv; while (len > 0) { - n = recv(sock, buf, len, MSG_PEEK); +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + if (cl->sslctx) + n = rfbssl_peek(cl, buf, len); + else +#endif + n = recv(sock, buf, len, MSG_PEEK); if (n == len) { @@ -564,13 +586,19 @@ rfbPeekExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) return n; } +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + if (cl->sslctx) { + if (rfbssl_pending(cl)) + continue; + } +#endif FD_ZERO(&fds); FD_SET(sock, &fds); tv.tv_sec = timeout / 1000; tv.tv_usec = (timeout % 1000) * 1000; n = select(sock+1, &fds, NULL, &fds, &tv); if (n < 0) { - rfbLogPerror("ReadExact: select"); + rfbLogPerror("PeekExact: select"); return n; } if (n == 0) { @@ -581,7 +609,7 @@ rfbPeekExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout) } #undef DEBUG_READ_EXACT #ifdef DEBUG_READ_EXACT - rfbLog("ReadExact %d bytes\n",len); + rfbLog("PeekExact %d bytes\n",len); for(n=0;noutputMutex); while (len > 0) { - n = write(sock, buf, len); +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + if (cl->sslctx) + n = rfbssl_write(cl, buf, len); + else +#endif + n = write(sock, buf, len); if (n > 0) { diff --git a/libvncserver/websockets.c b/libvncserver/websockets.c index e0d3cc9..63e2b53 100755 --- a/libvncserver/websockets.c +++ b/libvncserver/websockets.c @@ -32,6 +32,7 @@ #include #include +#include "rfbssl.h" #define FLASH_POLICY_RESPONSE "\n" #define SZ_FLASH_POLICY_RESPONSE 93 @@ -91,15 +92,15 @@ webSocketsCheck (rfbClientPtr cl) rfbErr("webSocketsHandshake: failed sending Flash policy response"); } return FALSE; - } else if (strncmp(bbuf, "\x16", 1) == 0) { - cl->webSocketsSSL = 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"; - /* TODO */ - /* bbuf = ... */ - return FALSE; } else { - cl->webSocketsSSL = FALSE; scheme = "ws"; } @@ -334,6 +335,30 @@ webSocketsEncode(rfbClientPtr cl, const char *src, int len) return sz; } +static int +ws_read(rfbClientPtr cl, char *buf, int len) +{ + int n; + if (cl->sslctx) { + n = rfbssl_read(cl, buf, len); + } else { + n = read(cl->sock, buf, len); + } + return n; +} + +static int +ws_peek(rfbClientPtr cl, char *buf, int len) +{ + int n; + if (cl->sslctx) { + n = rfbssl_peek(cl, buf, len); + } else { + n = recv(cl->sock, buf, len, MSG_PEEK); + } + return n; +} + int webSocketsDecode(rfbClientPtr cl, char *dst, int len) { @@ -343,10 +368,10 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len) buf = cl->decodeBuf; - n = recv(cl->sock, buf, len*2+2, MSG_PEEK); + n = ws_peek(cl, buf, len*2+2); if (n <= 0) { - rfbLog("recv of %d\n", n); + rfbErr("%s: recv of %d\n", __func__, n); return n; } @@ -355,7 +380,7 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len) /* Base64 encoded WebSockets stream */ if (buf[0] == '\xff') { - i = read(cl->sock, buf, 1); /* Consume marker */ + i = ws_read(cl, buf, 1); /* Consume marker */ buf++; n--; } @@ -364,7 +389,7 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len) return -1; } if (buf[0] == '\x00') { - i = read(cl->sock, buf, 1); /* Consume marker */ + i = ws_read(cl, buf, 1); /* Consume marker */ buf++; n--; } @@ -414,7 +439,7 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len) retlen += n; /* Consume the data from socket */ - i = read(cl->sock, buf, needlen); + i = ws_read(cl, buf, needlen); cl->carrylen = n - len; retlen -= cl->carrylen; @@ -445,7 +470,7 @@ webSocketsDecode(rfbClientPtr cl, char *dst, int len) } /* Consume what we need */ - if ((n = read(cl->sock, buf, needlen)) < needlen) { + if ((n = ws_read(cl, buf, needlen)) < needlen) { return n; } diff --git a/rfb/rfb.h b/rfb/rfb.h index 1a46e9a..b6fb7c0 100644 --- a/rfb/rfb.h +++ b/rfb/rfb.h @@ -368,6 +368,10 @@ typedef struct _rfbScreenInfo rfbDisplayFinishedHookPtr displayFinishedHook; /** xvpHook is called to handle an xvp client message */ rfbXvpHookPtr xvpHook; +#ifdef LIBVNCSERVER_WITH_WEBSOCKETS + char *sslkeyfile; + char *sslcertfile; +#endif } rfbScreenInfo, *rfbScreenInfoPtr; @@ -414,6 +418,8 @@ typedef struct _rfbStatList { struct _rfbStatList *Next; } rfbStatList; +typedef struct _rfbSslCtx rfbSslCtx; + typedef struct _rfbClientRec { /** back pointer to the screen */ @@ -637,8 +643,9 @@ typedef struct _rfbClientRec { rfbBool webSocketsSSL; rfbBool webSocketsBase64; - char encodeBuf[UPDATE_BUF_SIZE*2 + 2]; /* UTF-8 could double it + framing */ + rfbSslCtx *sslctx; + 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 */