diff options
| -rw-r--r-- | .appveyor.yml | 29 | ||||
| -rw-r--r-- | CMakeLists.txt | 20 | ||||
| -rw-r--r-- | client_examples/ppmtest.c | 13 | ||||
| -rw-r--r-- | libvncclient/rfbproto.c | 26 | ||||
| -rw-r--r-- | libvncclient/rfbsasl.c | 579 | ||||
| -rw-r--r-- | libvncclient/rfbsasl.h | 35 | ||||
| -rw-r--r-- | libvncclient/sockets.c | 56 | ||||
| -rw-r--r-- | libvncclient/tls.h | 5 | ||||
| -rw-r--r-- | libvncclient/tls_gnutls.c | 18 | ||||
| -rw-r--r-- | libvncclient/tls_none.c | 9 | ||||
| -rw-r--r-- | libvncclient/tls_openssl.c | 18 | ||||
| -rw-r--r-- | libvncclient/vncviewer.c | 13 | ||||
| -rw-r--r-- | rfb/rfbclient.h | 23 | ||||
| -rw-r--r-- | rfb/rfbconfig.h.cmakein | 3 | ||||
| -rw-r--r-- | rfb/rfbproto.h | 6 |
15 files changed, 838 insertions, 15 deletions
diff --git a/.appveyor.yml b/.appveyor.yml index dd07eeb..0393f3a 100644 --- a/.appveyor.yml +++ b/.appveyor.yml @@ -1,8 +1,14 @@ +#environment: +# APPVEYOR_RDP_PASSWORD: Pa55word + os: - Visual Studio 2013 - Visual Studio 2015 +#init: +# - ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1')) + install: - mkdir deps - cd deps @@ -22,13 +28,32 @@ install: - cmake . -DZLIB_INCLUDE_DIR=..\zlib -DZLIB_LIBRARY=..\zlib\debug\zlibstaticd.lib - cmake --build . - cd .. + # Berkeley DB - required by SASL + - curl -fsSL -o db-4.1.25.tar.gz http://download.oracle.com/berkeley-db/db-4.1.25.tar.gz + - 7z x db-4.1.25.tar.gz -so | 7z x -si -ttar > nul + - move db-4.1.25 db + - cd db\build_win32 + - C:\"Program Files (x86)"\"Microsoft Visual Studio 12.0"\Common7\IDE\devenv.exe db_dll.dsp /upgrade + - msbuild /p:Configuration=Release db_dll.vcxproj + - cd ..\.. + # Cyrus SASL + - curl -fsSL -o cyrus-sasl-2.1.26.tar.gz ftp://ftp.cyrusimap.org/cyrus-sasl/cyrus-sasl-2.1.26.tar.gz + - 7z x cyrus-sasl-2.1.26.tar.gz -so | 7z x -si -ttar > nul + - move cyrus-sasl-2.1.26 sasl + - cd sasl + - '"%vs120comntools%\VsDevCmd.bat"' + - nmake /f NTMakefile OPENSSL_INCLUDE=c:\OpenSSL-Win32\include OPENSSL_LIBPATH=c:\OpenSSL-Win32\lib DB_INCLUDE=c:\projects\libvncserver\deps\db\build_win32 DB_LIBPATH=c:\projects\libvncserver\deps\db\build_win32\release DB_LIB=libdb41.lib install + - cd .. # go back to source root - cd .. - build_script: - mkdir build - cd build - - cmake .. -DZLIB_INCLUDE_DIR=..\deps\zlib -DZLIB_LIBRARY=..\deps\zlib\debug\zlibstaticd.lib -DPNG_PNG_INCLUDE_DIR=..\deps\libpng -DPNG_LIBRARY=..\deps\libpng\debug\libpng16_staticd.lib + - cmake .. -DZLIB_INCLUDE_DIR=..\deps\zlib -DZLIB_LIBRARY=..\deps\zlib\debug\zlibstaticd.lib -DPNG_PNG_INCLUDE_DIR=..\deps\libpng -DPNG_LIBRARY=..\deps\libpng\debug\libpng16_staticd.lib -D SASL2_INCLUDE_DIR=c:\cmu\include -D LIBSASL2_LIBRARIES=c:\cmu\lib\libsasl.lib .. - cmake --build . - ctest -C Debug --output-on-failure + +#on_finish: +# - ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1')) + diff --git a/CMakeLists.txt b/CMakeLists.txt index 16f235e..430e909 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -47,6 +47,7 @@ option(WITH_TIGHTVNC_FILETRANSFER "Enable filetransfer if there is pthreads supp option(WITH_24BPP "Allow 24 bpp" ON) option(WITH_IPv6 "Enable IPv6 Support" ON) option(WITH_WEBSOCKETS "Build with websockets support" ON) +option(WITH_SASL "Build with SASL support" ON) @@ -264,6 +265,18 @@ endif(NOT HAVE_LIBVNCSERVER_IN_ADDR_T) TEST_BIG_ENDIAN(LIBVNCSERVER_WORDS_BIGENDIAN) +if(WITH_SASL) + find_path(SASL2_INCLUDE_DIR sasl/sasl.h) + find_library(LIBSASL2_LIBRARIES sasl2 libsasl.lib) +endif(WITH_SASL) + +if(WITH_SASL AND LIBSASL2_LIBRARIES AND SASL2_INCLUDE_DIR) + message(STATUS "Building with SASL: ${LIBSASL2_LIBRARIES} and ${SASL2_INCLUDE_DIR}") + set(LIBVNCSERVER_HAVE_SASL 1) + set(ADDITIONAL_LIBS ${ADDITIONAL_LIBS} ${LIBSASL2_LIBRARIES}) + include_directories(${SASL2_INCLUDE_DIR}) +endif(WITH_SASL AND LIBSASL2_LIBRARIES AND SASL2_INCLUDE_DIR) + # TODO: # LIBVNCSERVER_ENOENT_WORKAROUND # inline @@ -322,6 +335,13 @@ else() ) endif() +if(LIBVNCSERVER_HAVE_SASL) + set(LIBVNCCLIENT_SOURCES + ${LIBVNCCLIENT_SOURCES} + ${LIBVNCCLIENT_DIR}/rfbsasl.c + ) +endif() + if(ZLIB_FOUND) add_definitions(-DLIBVNCSERVER_HAVE_LIBZ) include_directories(${ZLIB_INCLUDE_DIR}) diff --git a/client_examples/ppmtest.c b/client_examples/ppmtest.c index b8602f0..eeafc22 100644 --- a/client_examples/ppmtest.c +++ b/client_examples/ppmtest.c @@ -58,12 +58,25 @@ static void SaveFramebufferAsPPM(rfbClient* client, int x, int y, int w, int h) fclose(f); } +char * getuser(rfbClient *client) +{ +return strdup("testuser@test"); +} + +char * getpassword(rfbClient *client) +{ +return strdup("Password"); +} + int main(int argc, char **argv) { rfbClient* client = rfbGetClient(8,3,4); time_t t=time(NULL); + client->GetUser = getuser; + client->GetPassword = getpassword; + if(argc>1 && !strcmp("-print",argv[1])) { client->GotFrameBufferUpdate = PrintRect; argv[1]=argv[0]; argv++; argc--; diff --git a/libvncclient/rfbproto.c b/libvncclient/rfbproto.c index e099f1a..27589b8 100644 --- a/libvncclient/rfbproto.c +++ b/libvncclient/rfbproto.c @@ -66,6 +66,10 @@ #include <gcrypt.h> #endif +#ifdef LIBVNCSERVER_HAVE_SASL +#include "rfbsasl.h" +#endif /* LIBVNCSERVER_HAVE_SASL */ + #include "minilzo.h" #include "tls.h" @@ -500,6 +504,9 @@ ReadSupportedSecurityType(rfbClient* client, uint32_t *result, rfbBool subAuth) #if defined(LIBVNCSERVER_HAVE_GNUTLS) || defined(LIBVNCSERVER_HAVE_LIBSSL) tAuth[loop]==rfbVeNCrypt || #endif +#ifdef LIBVNCSERVER_HAVE_SASL + tAuth[loop]==rfbSASL || +#endif /* LIBVNCSERVER_HAVE_SASL */ (tAuth[loop]==rfbARD && client->GetCredential) || (!subAuth && (tAuth[loop]==rfbTLS || (tAuth[loop]==rfbVeNCrypt && client->GetCredential)))) { @@ -1079,6 +1086,12 @@ InitialiseRFBConnection(rfbClient* client) if (!HandleVncAuth(client)) return FALSE; break; +#ifdef LIBVNCSERVER_HAVE_SASL + case rfbSASL: + if (!HandleSASLAuth(client)) return FALSE; + break; +#endif /* LIBVNCSERVER_HAVE_SASL */ + case rfbMSLogon: if (!HandleMSLogonAuth(client)) return FALSE; break; @@ -1117,6 +1130,12 @@ InitialiseRFBConnection(rfbClient* client) if (!HandleVncAuth(client)) return FALSE; break; +#ifdef LIBVNCSERVER_HAVE_SASL + case rfbSASL: + if (!HandleSASLAuth(client)) return FALSE; + break; +#endif /* LIBVNCSERVER_HAVE_SASL */ + default: rfbClientLog("Unknown sub authentication scheme from VNC server: %d\n", (int)subAuthScheme); @@ -1146,6 +1165,13 @@ InitialiseRFBConnection(rfbClient* client) if (!HandlePlainAuth(client)) return FALSE; break; +#ifdef LIBVNCSERVER_HAVE_SASL + case rfbVeNCryptX509SASL: + case rfbVeNCryptTLSSASL: + if (!HandleSASLAuth(client)) return FALSE; + break; +#endif /* LIBVNCSERVER_HAVE_SASL */ + default: rfbClientLog("Unknown sub authentication scheme from VNC server: %d\n", client->subAuthScheme); diff --git a/libvncclient/rfbsasl.c b/libvncclient/rfbsasl.c new file mode 100644 index 0000000..dc7d3bc --- /dev/null +++ b/libvncclient/rfbsasl.c @@ -0,0 +1,579 @@ +/* + * The software in this file is derived from the vncconnection.c source file + * from the GTK VNC Widget with modifications by S. Waterman <simon.waterman@zynstra.com> + * for compatibility with libvncserver. The copyright and license + * statements below apply only to this source file and to no other parts of the + * libvncserver library. + * + * GTK VNC Widget + * + * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws> + * Copyright (C) 2009-2010 Daniel P. Berrange <dan@berrange.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.0 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/* + * rfbsasl.c - functions to deal with client side of the SASL protocol. + */ + +#ifdef __STRICT_ANSI__ +#define _BSD_SOURCE +#define _POSIX_SOURCE +#define _XOPEN_SOURCE 600 +#endif + +#include <errno.h> +#include <rfb/rfbclient.h> + +#ifdef WIN32 +#undef SOCKET +#include <winsock2.h> +#define EWOULDBLOCK WSAEWOULDBLOCK +#define socklen_t int +#define close closesocket +#define read(sock,buf,len) recv(sock,buf,len,0) +#define write(sock,buf,len) send(sock,buf,len,0) +#ifdef LIBVNCSERVER_HAVE_WS2TCPIP_H +#undef socklen_t +#include <ws2tcpip.h> +#endif /* LIBVNCSERVER_HAVE_WS2TCPIP_H */ +#else /* WIN32 */ +#include <arpa/inet.h> +#endif /* WIN32 */ + +#include "rfbsasl.h" + +#include "tls.h" + +#ifdef _MSC_VER +# define snprintf _snprintf /* MSVC went straight to the underscored syntax */ +#endif + +/* + * NB, keep in sync with similar method in qemud/remote.c + */ +static char *vnc_connection_addr_to_string(char *host, int port) +{ + char * buf = (char *)malloc(strlen(host) + 7); + sprintf(buf, "%s;%hu", host, port); + return buf; +} + +static int log_func(void *context, + int level, + const char *message) +{ + rfbClientLog("SASL: %s\n", message); + + return SASL_OK; +} + +static int user_callback_adapt(void *context, + int id, + const char **result, + unsigned *len) +{ + rfbClient* client = (rfbClient *)context; + + if (id != SASL_CB_AUTHNAME) { + rfbClientLog("Unrecognized SASL callback ID %d\n", id); + return SASL_FAIL; + } + + if (!client->GetUser) { + rfbClientLog("Client user callback not found\n"); + return SASL_FAIL; + } + + *result = client->GetUser(client); + + if (! *result) return SASL_FAIL; + /**len = strlen(*result);*/ + return SASL_OK; +} + +static int password_callback_adapt(sasl_conn_t *conn, + void * context, + int id, + sasl_secret_t **secret) +{ + rfbClient* client = (rfbClient *)context; + char * password; + + if (id != SASL_CB_PASS) { + rfbClientLog("Unrecognized SASL callback ID %d\n", id); + return SASL_FAIL; + } + + if (client->saslSecret) { /* If we've already got it just return it. */ + *secret = client->saslSecret; + return SASL_OK; + } + + if (!client->GetPassword) { + rfbClientLog("Client password callback not found\n"); + return SASL_FAIL; + } + + password = client->GetPassword(client); + + if (! password) return SASL_FAIL; + + sasl_secret_t *lsec = (sasl_secret_t *)malloc(sizeof(sasl_secret_t) + strlen(password)); + if (!lsec) { + rfbClientLog("Could not allocate sasl_secret_t\n"); + return SASL_FAIL; + } + + strcpy(lsec->data, password); + lsec->len = strlen(password); + client->saslSecret = lsec; + *secret = lsec; + + /* Clear client password */ + size_t i; + for (i = 0; i < lsec->len; i++) { + password[i] = '\0'; + } + free(password); + + return SASL_OK; +} + +#define SASL_MAX_MECHLIST_LEN 300 +#define SASL_MAX_DATA_LEN (1024 * 1024) + +/* Perform the SASL authentication process + */ +rfbBool +HandleSASLAuth(rfbClient *client) +{ + sasl_conn_t *saslconn = NULL; + sasl_security_properties_t secprops; + const char *clientout; + char *serverin = NULL; + unsigned int clientoutlen, serverinlen; + int err, complete = 0; + char *localAddr = NULL, *remoteAddr = NULL; + const void *val; + sasl_ssf_t ssf; + sasl_callback_t saslcb[] = { + {SASL_CB_LOG, (void *)log_func, NULL}, + {SASL_CB_AUTHNAME, client->GetUser ? (void *)user_callback_adapt : NULL, client}, + {SASL_CB_PASS, client->GetPassword ? (void *)password_callback_adapt : NULL, client}, + { .id = 0 }, + }; + sasl_interact_t *interact = NULL; + uint32_t mechlistlen; + char *mechlist; + char *wantmech; + const char *mechname; + rfbBool ret; + + client->saslconn = NULL; + + /* Sets up the SASL library as a whole */ + err = sasl_client_init(NULL); + rfbClientLog("Client initialize SASL authentication %d\n", err); + if (err != SASL_OK) { + rfbClientLog("failed to initialize SASL library: %d (%s)\n", + err, sasl_errstring(err, NULL, NULL)); + goto error; + } + + /* Get local address in form IPADDR:PORT */ + struct sockaddr_storage localAddress; + socklen_t addressLength = sizeof(localAddress); + char buf[INET6_ADDRSTRLEN]; + int port; + + if (getsockname(client->sock, (struct sockaddr*)&localAddress, &addressLength)) { + rfbClientLog("failed to get local address\n"); + goto error; + } + + if (localAddress.ss_family == AF_INET) { + struct sockaddr_in *sa_in = (struct sockaddr_in*)&localAddress; + inet_ntop(AF_INET, &(sa_in->sin_addr), buf, INET_ADDRSTRLEN); + port = ntohs(sa_in->sin_port); + localAddr = vnc_connection_addr_to_string(buf, port); + } else if (localAddress.ss_family == AF_INET6) { + struct sockaddr_in6 *sa_in = (struct sockaddr_in6*)&localAddress; + inet_ntop(AF_INET6, &(sa_in->sin6_addr), buf, INET6_ADDRSTRLEN); + port = ntohs(sa_in->sin6_port); + localAddr = vnc_connection_addr_to_string(buf, port); + } else { + rfbClientLog("failed to get local address\n"); + goto error; + } + + /* Get remote address in form IPADDR:PORT */ + remoteAddr = vnc_connection_addr_to_string(client->serverHost, client->serverPort); + + rfbClientLog("Client SASL new host:'%s' local:'%s' remote:'%s'\n", client->serverHost, localAddr, remoteAddr); + + /* Setup a handle for being a client */ + err = sasl_client_new("vnc", + client->serverHost, + localAddr, + remoteAddr, + saslcb, + SASL_SUCCESS_DATA, + &saslconn); + free(localAddr); + free(remoteAddr); + + if (err != SASL_OK) { + rfbClientLog("Failed to create SASL client context: %d (%s)\n", + err, sasl_errstring(err, NULL, NULL)); + goto error; + } + + /* Initialize some connection props we care about */ + if (client->tlsSession) { + if (!(ssf = (sasl_ssf_t)GetTLSCipherBits(client))) { + rfbClientLog("%s", "invalid cipher size for TLS session\n"); + goto error; + } + + rfbClientLog("Setting external SSF %d\n", ssf); + err = sasl_setprop(saslconn, SASL_SSF_EXTERNAL, &ssf); + if (err != SASL_OK) { + rfbClientLog("cannot set external SSF %d (%s)\n", + err, sasl_errstring(err, NULL, NULL)); + goto error; + } + } + + memset (&secprops, 0, sizeof secprops); + /* If we've got TLS, we don't care about SSF */ + secprops.min_ssf = client->tlsSession ? 0 : 56; /* Equiv to DES supported by all Kerberos */ + secprops.max_ssf = client->tlsSession ? 0 : 100000; /* Very strong ! AES == 256 */ + secprops.maxbufsize = 100000; + /* If we're not TLS, then forbid any anonymous or trivially crackable auth */ + secprops.security_flags = client->tlsSession ? 0 : + SASL_SEC_NOANONYMOUS | SASL_SEC_NOPLAINTEXT; + + err = sasl_setprop(saslconn, SASL_SEC_PROPS, &secprops); + if (err != SASL_OK) { + rfbClientLog("cannot set security props %d (%s)\n", + err, sasl_errstring(err, NULL, NULL)); + goto error; + } + + /* Get the supported mechanisms from the server */ + if (!ReadFromRFBServer(client, (char *)&mechlistlen, 4)) { + rfbClientLog("failed to read mechlistlen\n"); + goto error; + } + mechlistlen = rfbClientSwap32IfLE(mechlistlen); + rfbClientLog("mechlistlen is %d\n", mechlistlen); + if (mechlistlen > SASL_MAX_MECHLIST_LEN) { + rfbClientLog("mechlistlen %d too long\n", mechlistlen); + goto error; + } + + mechlist = malloc(mechlistlen+1); + if (!ReadFromRFBServer(client, mechlist, mechlistlen)) { + free(mechlist); + goto error; + } + mechlist[mechlistlen] = '\0'; + + /* Allow the client to influence the mechanism selected. */ + if (client->GetSASLMechanism) { + wantmech = client->GetSASLMechanism(client, mechlist); + + if (wantmech && *wantmech != 0) { + if (strstr(mechlist, wantmech) == NULL) { + rfbClientLog("Client requested SASL mechanism %s not supported by server\n", + wantmech); + free(mechlist); + free(wantmech); + goto error; + } else { + free(mechlist); + mechlist = wantmech; + } + } + } + + rfbClientLog("Client start negotiation mechlist '%s'\n", mechlist); + + restart: + /* Start the auth negotiation on the client end first */ + err = sasl_client_start(saslconn, + mechlist, + &interact, + &clientout, + &clientoutlen, + &mechname); + if (err != SASL_OK && err != SASL_CONTINUE && err != SASL_INTERACT) { + rfbClientLog("Failed to start SASL negotiation: %d (%s)\n", + err, sasl_errdetail(saslconn)); + free(mechlist); + mechlist = NULL; + goto error; + } + + /* Need to gather some credentials from the client */ + if (err == SASL_INTERACT) { + rfbClientLog("User interaction required but not currently supported\n"); + goto error; + } + + rfbClientLog("Server start negotiation with mech %s. Data %d bytes %p '%s'\n", + mechname, clientoutlen, clientout, clientout); + + if (clientoutlen > SASL_MAX_DATA_LEN) { + rfbClientLog("SASL negotiation data too long: %d bytes\n", + clientoutlen); + goto error; + } + + /* Send back the chosen mechname */ + uint32_t mechnamelen = rfbClientSwap32IfLE(strlen(mechname)); + if (!WriteToRFBServer(client, (char *)&mechnamelen, 4)) goto error; + if (!WriteToRFBServer(client, (char *)mechname, strlen(mechname))) goto error; + + /* NB, distinction of NULL vs "" is *critical* in SASL */ + if (clientout) { + uint32_t colsw = rfbClientSwap32IfLE(clientoutlen + 1); + if (!WriteToRFBServer(client, (char *)&colsw, 4)) goto error; + if (!WriteToRFBServer(client, (char *)clientout, clientoutlen + 1)) goto error; + } else { + uint32_t temp = 0; + if (!WriteToRFBServer(client, (char *)&temp, 4)) goto error; + } + + rfbClientLog("%s", "Getting sever start negotiation reply\n"); + /* Read the 'START' message reply from server */ + if (!ReadFromRFBServer(client, (char *)&serverinlen, 4)) goto error; + serverinlen = rfbClientSwap32IfLE(serverinlen); + + if (serverinlen > SASL_MAX_DATA_LEN) { + rfbClientLog("SASL negotiation data too long: %d bytes\n", + serverinlen); + goto error; + } + + /* NB, distinction of NULL vs "" is *critical* in SASL */ + if (serverinlen) { + serverin = malloc(serverinlen); + if (!ReadFromRFBServer(client, serverin, serverinlen)) goto error; + serverin[serverinlen-1] = '\0'; + serverinlen--; + } else { + serverin = NULL; + } + if (!ReadFromRFBServer(client, (char *)&complete, 1)) goto error; + + rfbClientLog("Client start result complete: %d. Data %d bytes %p '%s'\n", + complete, serverinlen, serverin, serverin); + + /* Loop-the-loop... + * Even if the server has completed, the client must *always* do at least one step + * in this loop to verify the server isn't lying about something. Mutual auth */ + for (;;) { + restep: + err = sasl_client_step(saslconn, + serverin, + serverinlen, + &interact, + &clientout, + &clientoutlen); + if (err != SASL_OK && err != SASL_CONTINUE && err != SASL_INTERACT) { + rfbClientLog("Failed SASL step: %d (%s)\n", + err, sasl_errdetail(saslconn)); + goto error; + } + + /* Need to gather some credentials from the client */ + if (err == SASL_INTERACT) { + rfbClientLog("User interaction required but not currently supported\n"); + goto error; + } + + if (serverin) { + free(serverin); + serverin = NULL; + } + + rfbClientLog("Client step result %d. Data %d bytes %p '%s'\n", err, clientoutlen, clientout, clientout); + + /* Previous server call showed completion & we're now locally complete too */ + if (complete && err == SASL_OK) + break; + + /* Not done, prepare to talk with the server for another iteration */ + + /* NB, distinction of NULL vs "" is *critical* in SASL */ + if (clientout) { + uint32_t colsw = rfbClientSwap32IfLE(clientoutlen + 1); + if (!WriteToRFBServer(client, (char *)&colsw, 4)) goto error; + if (!WriteToRFBServer(client, (char *)clientout, clientoutlen + 1)) goto error; + } else { + uint32_t temp = 0; + if (!WriteToRFBServer(client, (char *)&temp, 4)) goto error; + } + + rfbClientLog("Server step with %d bytes %p\n", clientoutlen, clientout); + + if (!ReadFromRFBServer(client, (char *)&serverinlen, 4)) goto error; + serverinlen = rfbClientSwap32IfLE(serverinlen); + + if (serverinlen > SASL_MAX_DATA_LEN) { + rfbClientLog("SASL negotiation data too long: %d bytes\n", + serverinlen); + goto error; + } + + /* NB, distinction of NULL vs "" is *critical* in SASL */ + if (serverinlen) { + serverin = malloc(serverinlen); + if (!ReadFromRFBServer(client, serverin, serverinlen)) goto error; + serverin[serverinlen-1] = '\0'; + serverinlen--; + } else { + serverin = NULL; + } + if (!ReadFromRFBServer(client, (char *)&complete, 1)) goto error; + + rfbClientLog("Client step result complete: %d. Data %d bytes %p '%s'\n", + complete, serverinlen, serverin, serverin); + + /* This server call shows complete, and earlier client step was OK */ + if (complete && err == SASL_OK) { + free(serverin); + serverin = NULL; + break; + } + } + + /* Check for suitable SSF if non-TLS */ + if (!client->tlsSession) { + err = sasl_getprop(saslconn, SASL_SSF, &val); + if (err != SASL_OK) { + rfbClientLog("cannot query SASL ssf on connection %d (%s)\n", + err, sasl_errstring(err, NULL, NULL)); + goto error; + } + ssf = *(const int *)val; + rfbClientLog("SASL SSF value %d\n", ssf); + if (ssf < 56) { /* 56 == DES level, good for Kerberos */ + rfbClientLog("negotiation SSF %d was not strong enough\n", ssf); + goto error; + } + } + + rfbClientLog("%s", "SASL authentication complete\n"); + + uint32_t result; + if (!ReadFromRFBServer(client, (char *)&result, 4)) { + rfbClientLog("Failed to read authentication result\n"); + goto error; + } + result = rfbClientSwap32IfLE(result); + + if (result != 0) { + rfbClientLog("Authentication failure\n"); + goto error; + } + rfbClientLog("Authentication successful - switching to SSF\n"); + + /* This must come *after* check-auth-result, because the former + * is defined to be sent unencrypted, and setting saslconn turns + * on the SSF layer encryption processing */ + client->saslconn = saslconn; + + /* Clear SASL secret from memory if set - it'll be free'd on dispose */ + if (client->saslSecret) { + size_t i; + for (i = 0; i < client->saslSecret->len; i++) + client->saslSecret->data[i] = '\0'; + client->saslSecret->len = 0; + } + + return TRUE; + + error: + if (client->saslSecret) { + size_t i; + for (i = 0; i < client->saslSecret->len; i++) + client->saslSecret->data[i] = '\0'; + client->saslSecret->len = 0; + } + + if (saslconn) + sasl_dispose(&saslconn); + return FALSE; +} + +int +ReadFromSASL(rfbClient* client, char *out, unsigned int n) +{ + size_t want; + + if (client->saslDecoded == NULL) { + char *encoded; + int encodedLen; + int err, ret; + + encodedLen = 8192; + encoded = (char *)malloc(encodedLen); + + ret = read(client->sock, encoded, encodedLen); + if (ret < 0) { + free(encoded); + return ret; + } + if (ret == 0) { + free(encoded); + errno = EIO; + return -EIO; + } + + err = sasl_decode(client->saslconn, encoded, ret, + &client->saslDecoded, &client->saslDecodedLength); + free(encoded); + if (err != SASL_OK) { + rfbClientLog("Failed to decode SASL data %s\n", + sasl_errstring(err, NULL, NULL)); + return -EINVAL; + } + client->saslDecodedOffset = 0; + } + + want = client->saslDecodedLength - client->saslDecodedOffset; + if (want > n) + want = n; + + memcpy(out, + client->saslDecoded + client->saslDecodedOffset, + want); + client->saslDecodedOffset += want; + if (client->saslDecodedOffset == client->saslDecodedLength) { + client->saslDecodedLength = client->saslDecodedOffset = 0; + client->saslDecoded = NULL; + } + + if (!want) { + errno = EAGAIN; + return -EAGAIN; + } + + return want; +} diff --git a/libvncclient/rfbsasl.h b/libvncclient/rfbsasl.h new file mode 100644 index 0000000..8231096 --- /dev/null +++ b/libvncclient/rfbsasl.h @@ -0,0 +1,35 @@ +#ifndef RFBSASL_H +#define RFBSASL_H + +/* + * Copyright (C) 2017 S. Waterman. All Rights Reserved. + * + * 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/rfbclient.h> + +/* + * Perform the SASL authentication process + */ +rfbBool HandleSASLAuth(rfbClient *client); + +/* + * Read from SASL when the SASL SSF is in use. + */ +int ReadFromSASL(rfbClient* client, char *out, unsigned int n); + +#endif /* RFBSASL_H */ diff --git a/libvncclient/sockets.c b/libvncclient/sockets.c index 1019580..8ed51a5 100644 --- a/libvncclient/sockets.c +++ b/libvncclient/sockets.c @@ -59,6 +59,10 @@ #endif #include "tls.h" +#ifdef LIBVNCSERVER_HAVE_SASL +#include "rfbsasl.h" +#endif /* LIBVNCSERVER_HAVE_SASL */ + #ifdef _MSC_VER # define snprintf _snprintf #endif @@ -154,16 +158,24 @@ ReadFromRFBServer(rfbClient* client, char *out, unsigned int n) while (client->buffered < n) { int i; - if (client->tlsSession) { + if (client->tlsSession) i = ReadFromTLS(client, client->buf + client->buffered, RFB_BUF_SIZE - client->buffered); - } else { + else +#ifdef LIBVNCSERVER_HAVE_SASL + if (client->saslconn) + i = ReadFromSASL(client, client->buf + client->buffered, RFB_BUF_SIZE - client->buffered); + else { +#endif /* LIBVNCSERVER_HAVE_SASL */ i = read(client->sock, client->buf + client->buffered, RFB_BUF_SIZE - client->buffered); +#ifdef WIN32 + if (i < 0) errno=WSAGetLastError(); +#endif +#ifdef LIBVNCSERVER_HAVE_SASL } +#endif + if (i <= 0) { if (i < 0) { -#ifdef WIN32 - errno=WSAGetLastError(); -#endif if (errno == EWOULDBLOCK || errno == EAGAIN) { /* TODO: ProcessXtEvents(); @@ -192,11 +204,15 @@ ReadFromRFBServer(rfbClient* client, char *out, unsigned int n) while (n > 0) { int i; - if (client->tlsSession) { + if (client->tlsSession) i = ReadFromTLS(client, out, n); - } else { + else +#ifdef LIBVNCSERVER_HAVE_SASL + if (client->saslconn) + i = ReadFromSASL(client, out, n); + else +#endif i = read(client->sock, out, n); - } if (i <= 0) { if (i < 0) { @@ -248,6 +264,12 @@ WriteToRFBServer(rfbClient* client, char *buf, int n) fd_set fds; int i = 0; int j; + const char *obuf = buf; +#ifdef LIBVNCSERVER_HAVE_SASL + const char *output; + unsigned int outputlen; + int err; +#endif /* LIBVNCSERVER_HAVE_SASL */ if (client->serverPort==-1) return TRUE; /* vncrec playing */ @@ -259,9 +281,23 @@ WriteToRFBServer(rfbClient* client, char *buf, int n) return TRUE; } +#ifdef LIBVNCSERVER_HAVE_SASL + if (client->saslconn) { + err = sasl_encode(client->saslconn, + buf, n, + &output, &outputlen); + if (err != SASL_OK) { + rfbClientLog("Failed to encode SASL data %s", + sasl_errstring(err, NULL, NULL)); + return FALSE; + } + obuf = output; + n = outputlen; + } +#endif /* LIBVNCSERVER_HAVE_SASL */ while (i < n) { - j = write(client->sock, buf + i, (n - i)); + j = write(client->sock, obuf + i, (n - i)); if (j <= 0) { if (j < 0) { #ifdef WIN32 @@ -294,8 +330,6 @@ WriteToRFBServer(rfbClient* client, char *buf, int n) return TRUE; } - - static int initSockets() { #ifdef WIN32 WSADATA trash; diff --git a/libvncclient/tls.h b/libvncclient/tls.h index 48d159b..a5a2ac6 100644 --- a/libvncclient/tls.h +++ b/libvncclient/tls.h @@ -48,4 +48,9 @@ int WriteToTLS(rfbClient* client, char *buf, unsigned int n); /* Free TLS resources */ void FreeTLS(rfbClient* client); +#ifdef LIBVNCSERVER_HAVE_SASL +/* Get the number of bits in the current cipher */ +int GetTLSCipherBits(rfbClient* client); +#endif /* LIBVNCSERVER_HAVE_SASL */ + #endif /* TLS_H */ diff --git a/libvncclient/tls_gnutls.c b/libvncclient/tls_gnutls.c index f49fa85..f146d2a 100644 --- a/libvncclient/tls_gnutls.c +++ b/libvncclient/tls_gnutls.c @@ -346,6 +346,10 @@ ReadVeNCryptSecurityType(rfbClient* client, uint32_t *result) if (t==rfbVeNCryptTLSNone || t==rfbVeNCryptTLSVNC || t==rfbVeNCryptTLSPlain || +#ifdef LIBVNCSERVER_HAVE_SASL + t==rfbVeNCryptTLSSASL || + t==rfbVeNCryptX509SASL || +#endif /*LIBVNCSERVER_HAVE_SASL */ t==rfbVeNCryptX509None || t==rfbVeNCryptX509VNC || t==rfbVeNCryptX509Plain) @@ -505,6 +509,9 @@ HandleVeNCryptAuth(rfbClient* client) case rfbVeNCryptTLSNone: case rfbVeNCryptTLSVNC: case rfbVeNCryptTLSPlain: +#ifdef LIBVNCSERVER_HAVE_SASL + case rfbVeNCryptTLSSASL: +#endif /* LIBVNCSERVER_HAVE_SASL */ anonTLS = TRUE; break; default: @@ -631,3 +638,14 @@ void FreeTLS(rfbClient* client) client->tlsSession = NULL; } } + +#ifdef LIBVNCSERVER_HAVE_SASL +int +GetTLSCipherBits(rfbClient* client) +{ + gnutls_cipher_algorithm_t cipher = gnutls_cipher_get((gnutls_session_t)client->tlsSession); + + return gnutls_cipher_get_key_size(cipher) * 8; +} +#endif /* LIBVNCSERVER_HAVE_SASL */ + diff --git a/libvncclient/tls_none.c b/libvncclient/tls_none.c index 91a9f93..4dfcb27 100644 --- a/libvncclient/tls_none.c +++ b/libvncclient/tls_none.c @@ -56,3 +56,12 @@ void FreeTLS(rfbClient* client) } +#ifdef LIBVNCSERVER_HAVE_SASL +int +GetTLSCipherBits(rfbClient* client) +{ + rfbClientLog("TLS is not supported.\n"); + return 0; +} +#endif /* LIBVNCSERVER_HAVE_SASL */ + diff --git a/libvncclient/tls_openssl.c b/libvncclient/tls_openssl.c index 2bdf3eb..fe60147 100644 --- a/libvncclient/tls_openssl.c +++ b/libvncclient/tls_openssl.c @@ -475,6 +475,10 @@ ReadVeNCryptSecurityType(rfbClient* client, uint32_t *result) if (t==rfbVeNCryptTLSNone || t==rfbVeNCryptTLSVNC || t==rfbVeNCryptTLSPlain || +#ifdef LIBVNCSERVER_HAVE_SASL + t==rfbVeNCryptTLSSASL || + t==rfbVeNCryptX509SASL || +#endif /*LIBVNCSERVER_HAVE_SASL */ t==rfbVeNCryptX509None || t==rfbVeNCryptX509VNC || t==rfbVeNCryptX509Plain) @@ -576,6 +580,9 @@ HandleVeNCryptAuth(rfbClient* client) case rfbVeNCryptTLSNone: case rfbVeNCryptTLSVNC: case rfbVeNCryptTLSPlain: +#ifdef LIBVNCSERVER_HAVE_SASL + case rfbVeNCryptTLSSASL: +#endif /* LIBVNCSERVER_HAVE_SASL */ anonTLS = TRUE; break; default: @@ -679,3 +686,14 @@ void FreeTLS(rfbClient* client) SSL_free(client->tlsSession); } +#ifdef LIBVNCSERVER_HAVE_SASL +int GetTLSCipherBits(rfbClient* client) +{ + SSL *ssl = (SSL *)(client->tlsSession); + + const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl); + + return SSL_CIPHER_get_bits(cipher, NULL); +} +#endif /* LIBVNCSERVER_HAVE_SASL */ + diff --git a/libvncclient/vncviewer.c b/libvncclient/vncviewer.c index 780a1cb..407b4a5 100644 --- a/libvncclient/vncviewer.c +++ b/libvncclient/vncviewer.c @@ -350,6 +350,13 @@ rfbClient* rfbGetClient(int bitsPerSample,int samplesPerPixel, client->listen6Sock = -1; client->listen6Address = NULL; client->clientAuthSchemes = NULL; + +#ifdef LIBVNCSERVER_HAVE_SASL + client->GetSASLMechanism = NULL; + client->GetUser = NULL; + client->saslSecret = NULL; +#endif /* LIBVNCSERVER_HAVE_SASL */ + return client; } @@ -534,5 +541,11 @@ void rfbClientCleanup(rfbClient* client) { free(client->destHost); if (client->clientAuthSchemes) free(client->clientAuthSchemes); + +#ifdef LIBVNCSERVER_HAVE_SASL + if (client->saslSecret) + free(client->saslSecret); +#endif /* LIBVNCSERVER_HAVE_SASL */ + free(client); } diff --git a/rfb/rfbclient.h b/rfb/rfbclient.h index 4ac9cd6..72d672a 100644 --- a/rfb/rfbclient.h +++ b/rfb/rfbclient.h @@ -52,6 +52,10 @@ #include <rfb/rfbproto.h> #include <rfb/keysym.h> +#ifdef LIBVNCSERVER_HAVE_SASL +#include <sasl/sasl.h> +#endif /* LIBVNCSERVER_HAVE_SASL */ + #define rfbClientSwap16IfLE(s) \ (*(char *)&client->endianTest ? ((((s) & 0xff) << 8) | (((s) >> 8) & 0xff)) : (s)) @@ -205,6 +209,11 @@ typedef rfbBool (*GotJpegProc)(struct _rfbClient* client, const uint8_t* buffer, typedef rfbBool (*LockWriteToTLSProc)(struct _rfbClient* client); typedef rfbBool (*UnlockWriteToTLSProc)(struct _rfbClient* client); +#ifdef LIBVNCSERVER_HAVE_SASL +typedef char* (*GetUserProc)(struct _rfbClient* client); +typedef char* (*GetSASLMechanismProc)(struct _rfbClient* client, char* mechlist); +#endif /* LIBVNCSERVER_HAVE_SASL */ + typedef struct _rfbClient { uint8_t* frameBuffer; int width, height; @@ -399,6 +408,20 @@ typedef struct _rfbClient { GotBitmapProc GotBitmap; /** Hook for custom JPEG decoding and rendering */ GotJpegProc GotJpeg; + +#ifdef LIBVNCSERVER_HAVE_SASL + sasl_conn_t *saslconn; + const char *saslDecoded; + unsigned int saslDecodedLength; + unsigned int saslDecodedOffset; + sasl_secret_t *saslSecret; + + /* Callback to allow the client to choose a preferred mechanism. The string returned will + be freed once no longer required. */ + GetSASLMechanismProc GetSASLMechanism; + GetUserProc GetUser; + +#endif /* LIBVNCSERVER_HAVE_SASL */ } rfbClient; /* cursor.c */ diff --git a/rfb/rfbconfig.h.cmakein b/rfb/rfbconfig.h.cmakein index c4dc5c0..7638921 100644 --- a/rfb/rfbconfig.h.cmakein +++ b/rfb/rfbconfig.h.cmakein @@ -148,6 +148,9 @@ /* Define to 1 if OpenSSL is present */ #cmakedefine LIBVNCSERVER_HAVE_LIBSSL 1 +/* Define to 1 if Cyrus SASL is present */ +#cmakedefine LIBVNCSERVER_HAVE_SASL 1 + /* Define to 1 to build with websockets */ #cmakedefine LIBVNCSERVER_WITH_WEBSOCKETS 1 diff --git a/rfb/rfbproto.h b/rfb/rfbproto.h index f0d6ea1..c5b2723 100644 --- a/rfb/rfbproto.h +++ b/rfb/rfbproto.h @@ -67,9 +67,8 @@ typedef int8_t rfbBool; #include <sys/timeb.h> #include <winsock2.h> -#else -#include <rfb/rfbconfig.h> #endif +#include <rfb/rfbconfig.h> #ifdef LIBVNCSERVER_HAVE_LIBZ #include <zlib.h> @@ -287,6 +286,9 @@ typedef char rfbProtocolVersionMsg[13]; /* allow extra byte for null */ #define rfbUltra 17 #define rfbTLS 18 #define rfbVeNCrypt 19 +#ifdef LIBVNCSERVER_HAVE_SASL +#define rfbSASL 20 +#endif /* LIBVNCSERVER_HAVE_SASL */ #define rfbARD 30 #define rfbMSLogon 0xfffffffa |