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-rw-r--r--x11vnc/sslhelper.c1114
1 files changed, 1114 insertions, 0 deletions
diff --git a/x11vnc/sslhelper.c b/x11vnc/sslhelper.c
new file mode 100644
index 0000000..d55ac76
--- /dev/null
+++ b/x11vnc/sslhelper.c
@@ -0,0 +1,1114 @@
+/* -- sslhelper.c -- */
+
+#include "x11vnc.h"
+#include "inet.h"
+#include "cleanup.h"
+#include "screen.h"
+#include "scan.h"
+
+#if LIBVNCSERVER_HAVE_FORK
+#if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID
+#define FORK_OK
+#endif
+#endif
+
+int openssl_sock = -1;
+pid_t openssl_last_helper_pid = 0;
+
+#if !LIBVNCSERVER_HAVE_LIBSSL
+int openssl_present(void) {return 0;}
+void openssl_init(void) {
+ rfbLog("not compiled with libssl support.\n");
+ clean_up_exit(1);
+}
+void openssl_port(void) {}
+void check_openssl(void) {}
+void ssh_helper_pid(pid_t pid, int sock) {sock = pid;}
+#else
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+int openssl_present(void);
+void openssl_init(void);
+void openssl_port(void);
+void check_openssl(void);
+void ssh_helper_pid(pid_t pid, int sock);
+
+static SSL_CTX *ctx = NULL;
+static RSA *rsa_512 = NULL;
+static RSA *rsa_1024 = NULL;
+static SSL *ssl = NULL;
+
+
+static void init_prng(void);
+static void sslerrexit(void);
+static char *create_tmp_pem(void);
+static int ssl_init(int csock, int ssock);
+static void ssl_xfer(int csock, int ssock);
+
+#ifndef FORK_OK
+void openssl_init(void) {
+ rfbLog("openssl_init: fork is not supported. cannot create"
+ " ssl helper process.\n");
+ clean_up_exit(1);
+}
+int openssl_present(void) {return 0;}
+#else
+int openssl_present(void) {return 1;}
+
+static void sslerrexit(void) {
+ unsigned long err = ERR_get_error();
+ char str[256];
+
+ if (err) {
+ ERR_error_string(err, str);
+ fprintf(stderr, "ssl error: %s\n", str);
+ }
+ clean_up_exit(1);
+}
+
+static char *create_tmp_pem(void) {
+ pid_t pid, pidw;
+ FILE *in, *out;
+ char cnf[] = "/tmp/x11vnc-cnf.XXXXXX";
+ char pem[] = "/tmp/x11vnc-pem.XXXXXX";
+ char str[4096], line[1024], *path, *p, *exe;
+ int found_openssl = 0, cnf_fd, pem_fd, status, db = 1;
+ struct stat sbuf;
+ char tmpl[] =
+"[ req ]\n"
+"prompt = no\n"
+"default_bits = 1024\n"
+"encrypt_key = yes\n"
+"distinguished_name = req_dn\n"
+"x509_extensions = cert_type\n"
+"\n"
+"[ req_dn ]\n"
+"countryName=AU\n"
+"localityName=%s\n"
+"organizationalUnitName=%s-%f\n"
+"commonName=x11vnc-%d\n"
+"emailAddress=nobody@x11vnc.server\n"
+"\n"
+"[ cert_type ]\n"
+"nsCertType = server\n"
+;
+
+ if (no_external_cmds) {
+ rfbLog("create_tmp_pem: cannot run external commands.\n");
+ return NULL;
+ }
+ rfbLog("\n");
+ rfbLog("Creating a temporary, self-signed PEM certificate...\n");
+ rfbLog("This will NOT prevent man-in-the-middle attacks unless you\n");
+ rfbLog("get the certificate information to the VNC viewers ssl\n");
+ rfbLog("tunnel configuration. But it will prevent passive sniffing.\n");
+
+ if (! getenv("PATH")) {
+ return NULL;
+ }
+ path = strdup(getenv("PATH"));
+
+ /* find openssl binary: */
+ exe = (char *) malloc(strlen(path) + strlen("/openssl") + 1);
+ p = strtok(path, ":");
+
+ while (p) {
+ sprintf(exe, "%s/openssl", p);
+ if (stat(exe, &sbuf) == 0) {
+ if (! S_ISDIR(sbuf.st_mode)) {
+ found_openssl = 1;
+ break;
+ }
+ }
+ p = strtok(NULL, ":");
+ }
+ free(path);
+
+ if (! found_openssl) {
+ return NULL;
+ }
+
+ cnf_fd = mkstemp(cnf);
+ pem_fd = mkstemp(pem);
+
+ if (cnf_fd < 0 || pem_fd < 0) {
+ return NULL;
+ }
+
+ close(pem_fd);
+
+ /* create template file with our made up stuff: */
+ sprintf(str, tmpl, UT.sysname, UT.nodename, dnow(), (int) getpid());
+ write(cnf_fd, str, strlen(str));
+ close(cnf_fd);
+
+ /* make RSA key */
+ pid = fork();
+ if (pid < 0) {
+ return NULL;
+ } else if (pid == 0) {
+ int i;
+ for (i=0; i<256; i++) {
+ close(i);
+ }
+ execlp(exe, exe, "req", "-new", "-x509", "-nodes",
+ "-config", cnf, "-out", pem, "-keyout", pem, (char *)0);
+ exit(1);
+ }
+ pidw = waitpid(pid, &status, 0);
+ if (pidw != pid) {
+ return NULL;
+ }
+ if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+ ;
+ } else {
+ return NULL;
+ }
+
+ /* make DH parameters */
+ pid = fork();
+ if (pid < 0) {
+ return NULL;
+ } else if (pid == 0) {
+ int i;
+ for (i=0; i<256; i++) {
+ close(i);
+ }
+ execlp(exe, exe, "dhparam", "-out", cnf, "512", (char *)0);
+ exit(1);
+ }
+ pidw = waitpid(pid, &status, 0);
+ if (pidw != pid) {
+ return NULL;
+ }
+ if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+ ;
+ } else {
+ return NULL;
+ }
+
+ /* append result: */
+ in = fopen(cnf, "r");
+ if (in == NULL) {
+ return NULL;
+ }
+ out = fopen(pem, "a");
+ if (out == NULL) {
+ fclose(in);
+ return NULL;
+ }
+ while (fgets(line, 1024, in) != NULL) {
+ fprintf(out, "%s", line);
+ }
+ fclose(in);
+ fclose(out);
+
+ unlink(cnf);
+ free(exe);
+
+ if (db) {
+ char cmd[100];
+ sprintf(cmd, "openssl x509 -text -in %s", pem);
+ fprintf(stderr, "\n");
+ system(cmd);
+ fprintf(stderr, "\n");
+ }
+
+ return strdup(pem);
+}
+
+void openssl_init(void) {
+ int db = 0, tmp_pem = 0, do_dh = 1;
+ FILE *in;
+ double ds;
+ long mode;
+
+ if (! quiet) {
+ rfbLog("\n");
+ rfbLog("Initializing SSL.\n");
+ }
+ if (db) fprintf(stderr, "\nSSL_load_error_strings()\n");
+
+ SSL_load_error_strings();
+
+ if (db) fprintf(stderr, "SSL_library_init()\n");
+
+ SSL_library_init();
+
+ if (db) fprintf(stderr, "init_prng()\n");
+
+ init_prng();
+
+ ctx = SSL_CTX_new( SSLv23_server_method() );
+
+ if (ctx == NULL) {
+ rfbLog("openssl_init: SSL_CTX_new failed.\n");
+ sslerrexit();
+ }
+
+ ds = dnow();
+ rsa_512 = RSA_generate_key(512,RSA_F4,NULL,NULL);
+ if (rsa_512 == NULL) {
+ rfbLog("openssl_init: RSA_generate_key(512) failed.\n");
+ sslerrexit();
+ }
+
+ rfbLog("created 512 bit temporary RSA key: %.3fs\n", dnow() - ds);
+
+ ds = dnow();
+ rsa_1024 = RSA_generate_key(1024,RSA_F4,NULL,NULL);
+ if (rsa_1024 == NULL) {
+ rfbLog("openssl_init: RSA_generate_key(1024) failed.\n");
+ sslerrexit();
+ }
+
+ rfbLog("created 1024 bit temporary RSA key: %.3fs\n", dnow() - ds);
+
+ if (db) fprintf(stderr, "SSL_CTX_set_tmp_rsa()\n");
+
+ if (! SSL_CTX_set_tmp_rsa(ctx, rsa_1024)) {
+ rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
+ sslerrexit();
+ }
+
+ mode = 0;
+ mode |= SSL_MODE_ENABLE_PARTIAL_WRITE;
+ mode |= SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
+ SSL_CTX_set_mode(ctx, mode);
+
+ SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
+ SSL_CTX_set_timeout(ctx, 300);
+
+ ds = dnow();
+ if (! openssl_pem) {
+ openssl_pem = create_tmp_pem();
+ if (! openssl_pem) {
+ rfbLog("openssl_init: could not create temporary,"
+ " self-signed PEM.\n");
+ clean_up_exit(1);
+ }
+ tmp_pem = 1;
+ }
+
+ rfbLog("using PEM %s %.3fs\n", openssl_pem, dnow() - ds);
+
+ if (do_dh) {
+ DH *dh;
+ BIO *bio;
+
+ ds = dnow();
+ in = fopen(openssl_pem, "r");
+ if (in == NULL) {
+ rfbLogPerror("fopen");
+ clean_up_exit(1);
+ }
+ bio = BIO_new_fp(in, BIO_CLOSE|BIO_FP_TEXT);
+ if (! bio) {
+ rfbLog("openssl_init: BIO_new_fp() failed.\n");
+ sslerrexit();
+ }
+ dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
+ if (dh == NULL) {
+ rfbLog("openssl_init: PEM_read_bio_DHparams() failed.\n");
+ BIO_free(bio);
+ sslerrexit();
+ }
+ BIO_free(bio);
+ SSL_CTX_set_tmp_dh(ctx, dh);
+ rfbLog("loaded Diffie Hellman %d bits, %.3fs\n",
+ 8*DH_size(dh), dnow()-ds);
+ DH_free(dh);
+ }
+
+ if (! SSL_CTX_use_certificate_chain_file(ctx, openssl_pem)) {
+ rfbLog("openssl_init: SSL_CTX_use_certificate_chain_file() failed.\n");
+ sslerrexit();
+ }
+ if(! SSL_CTX_use_RSAPrivateKey_file(ctx, openssl_pem,
+ SSL_FILETYPE_PEM)) {
+ rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
+ sslerrexit();
+ }
+ if (! SSL_CTX_check_private_key(ctx)) {
+ rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
+ sslerrexit();
+ }
+
+ if (tmp_pem && ! getenv("X11VNC_KEEP_TMP_PEM")) {
+ if (getenv("X11VNC_SHOW_TMP_PEM")) {
+ FILE *in = fopen(openssl_pem, "r");
+ if (in != NULL) {
+ char line[128];
+ fprintf(stderr, "\n");
+ while (fgets(line, 128, in) != NULL) {
+ fprintf(stderr, "%s", line);
+ }
+ fprintf(stderr, "\n");
+ fclose(in);
+ }
+
+ }
+ unlink(openssl_pem);
+ free(openssl_pem);
+ }
+
+ if (ssl_verify) {
+ struct stat sbuf;
+ int lvl;
+ if (stat(ssl_verify, &sbuf) != 0) {
+ rfbLog("openssl_init: -sslverify does not exists %s.\n",
+ ssl_verify);
+ rfbLogPerror("stat");
+ clean_up_exit(1);
+ }
+ if (! S_ISDIR(sbuf.st_mode)) {
+ if (! SSL_CTX_load_verify_locations(ctx, ssl_verify,
+ NULL)) {
+ rfbLog("openssl_init: SSL_CTX_load_verify_"
+ "locations() failed.\n");
+ sslerrexit();
+ }
+ } else {
+ if (! SSL_CTX_load_verify_locations(ctx, NULL,
+ ssl_verify)) {
+ rfbLog("openssl_init: SSL_CTX_load_verify_"
+ "locations() failed.\n");
+ sslerrexit();
+ }
+ }
+ lvl = SSL_VERIFY_FAIL_IF_NO_PEER_CERT|SSL_VERIFY_PEER;
+ SSL_CTX_set_verify(ctx, lvl, NULL);
+ } else {
+ SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+ }
+
+ if (db) fprintf(stderr, "\n");
+}
+
+void openssl_port(void) {
+ int sock, shutdown = 0;
+ static int port = 0;
+ static in_addr_t iface = 0;
+ int db = 0;
+
+ if (! screen) {
+ rfbLog("openssl_port: no screen!\n");
+ clean_up_exit(1);
+ }
+
+ if (screen->listenSock > -1 && screen->port > 0) {
+ port = screen->port;
+ shutdown = 1;
+ }
+ if (screen->listenInterface) {
+ iface = screen->listenInterface;
+ }
+
+ if (shutdown) {
+ if (db) fprintf(stderr, "shutting down %d/%d\n",
+ port, screen->listenSock);
+ rfbShutdownSockets(screen);
+ }
+
+ sock = rfbListenOnTCPPort(port, iface);
+ if (sock < 0) {
+ rfbLog("openssl_port: could not reopen port %d\n", port);
+ clean_up_exit(1);
+ }
+ if (db) fprintf(stderr, "listen on port/sock %d/%d\n", port, sock);
+ openssl_sock = sock;
+
+ ssl_initialized = 1;
+}
+
+static void lose_ram(void) {
+ /*
+ * for a forked child that will be around for a long time
+ * without doing exec(). we really should re-exec, but a pain
+ * to redo all SSL ctx.
+ */
+ free_old_fb(main_fb, rfb_fb, cmap8to24_fb);
+ main_fb = NULL;
+ rfb_fb = NULL;
+ cmap8to24_fb = NULL;
+
+ if (snap_fb) {
+ free(snap_fb);
+ snap_fb = NULL;
+ }
+ if (raw_fb) {
+ free(raw_fb);
+ raw_fb = NULL;
+ }
+ free_tiles();
+}
+
+void ssh_helper_pid(pid_t pid, int sock) {
+# define HPSIZE 256
+ static pid_t helpers[HPSIZE];
+ static int sockets[HPSIZE], first = 1;
+ int i, empty, set;
+
+ if (first) {
+ for (i=0; i < HPSIZE; i++) {
+ helpers[i] = 0;
+ sockets[i] = 0;
+ }
+ first = 0;
+ }
+
+ if (pid == 0) {
+ /* killall */
+ for (i=0; i < HPSIZE; i++) {
+ if (helpers[i] == 0) {
+ continue;
+ sockets[i] = -1;
+ }
+ if (kill(helpers[i], 0) == 0) {
+ int status;
+ if (sockets[i] >= 0) {
+ close(sockets[i]);
+ }
+ kill(helpers[i], SIGTERM);
+#if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID
+ waitpid(helpers[i], &status, WNOHANG);
+#endif
+ }
+ helpers[i] = 0;
+ sockets[i] = -1;
+ }
+ return;
+ }
+ /* add */
+ set = 0;
+ empty = -1;
+ for (i=0; i < HPSIZE; i++) {
+ if (helpers[i] == pid) {
+ if (sock == -1) {
+ helpers[i] = 0;
+ }
+ sockets[i] = sock;
+ set = 1;
+ } else if (empty == -1 && helpers[i] == 0) {
+ empty = i;
+ }
+ }
+ if (set || sock == -1) {
+ return;
+ }
+ if (empty >= 0) {
+ helpers[empty] = pid;
+ sockets[empty] = sock;
+ return;
+ }
+ for (i=0; i < HPSIZE; i++) {
+ if (helpers[i] == 0) {
+ continue;
+ }
+ if (kill(helpers[i], 0) != 0) {
+ helpers[i] = 0;
+ sockets[i] = -1;
+
+ if (empty == -1) {
+ empty = i;
+ }
+ }
+ }
+ if (empty >= 0) {
+ helpers[empty] = pid;
+ sockets[empty] = sock;
+ }
+}
+
+void accept_openssl(void) {
+ int sock, cport, csock, vsock;
+ int status, n, db = 0;
+ struct sockaddr_in addr;
+ socklen_t addrlen = sizeof(addr);
+ char cookie[128], rcookie[128], *name;
+ rfbClientPtr client;
+ pid_t pid;
+
+ openssl_last_helper_pid = 0;
+
+ sock = accept(openssl_sock, (struct sockaddr *)&addr, &addrlen);
+ if (sock < 0) {
+ rfbLog("accept_openssl: accept connection failed\n");
+ rfbLogPerror("accept");
+ return;
+ }
+ if (db) fprintf(stderr, "accept_openssl: sock: %d\n", sock);
+
+ cport = find_free_port(20000, 0);
+ if (! cport) {
+ rfbLog("accept_openssl: could not find open port.\n");
+ close(sock);
+ return;
+ }
+ if (db) fprintf(stderr, "accept_openssl: cport: %d\n", cport);
+
+ csock = rfbListenOnTCPPort(cport, htonl(INADDR_LOOPBACK));
+ if (csock < 0) {
+ rfbLog("accept_openssl: could not listen on port %d.\n",
+ cport);
+ close(sock);
+ return;
+ }
+ if (db) fprintf(stderr, "accept_openssl: csock: %d\n", csock);
+
+ fflush(stderr);
+ sprintf(cookie, "%f/%f", dnow(), x11vnc_start);
+
+ name = get_remote_host(sock);
+ if (name) {
+ rfbLog("SSL: spawning helper process to handle: %s\n", name);
+ free(name);
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ rfbLog("accept_openssl: could not fork.\n");
+ rfbLogPerror("fork");
+ close(sock);
+ close(csock);
+ return;
+ } else if (pid == 0) {
+ int i, vncsock, sslsock = sock;
+
+ signal(SIGHUP, SIG_DFL);
+ signal(SIGINT, SIG_DFL);
+ signal(SIGQUIT, SIG_DFL);
+ signal(SIGTERM, SIG_DFL);
+
+ for (i=0; i<256; i++) {
+ if (i != sslsock && i != 2) {
+ close(i);
+ }
+ }
+
+ lose_ram();
+
+ vncsock = rfbConnectToTcpAddr("127.0.0.1", cport);
+ if (vncsock < 0) {
+ close(vncsock);
+ exit(1);
+ }
+ if (! ssl_init(vncsock, sslsock)) {
+ close(vncsock);
+ exit(1);
+ }
+ write(vncsock, cookie, strlen(cookie));
+ ssl_xfer(vncsock, sslsock);
+ exit(0);
+ }
+ close(sock);
+
+ vsock = accept(csock, (struct sockaddr *)&addr, &addrlen);
+ close(csock);
+ if (vsock < 0) {
+ rfbLog("accept_openssl: connection from ssl_helper failed.\n");
+ rfbLogPerror("accept");
+
+ kill(pid, SIGTERM);
+ waitpid(pid, &status, WNOHANG);
+ return;
+ }
+ if (db) fprintf(stderr, "accept_openssl: vsock: %d\n", vsock);
+
+ n = read(vsock, rcookie, strlen(cookie));
+ if (n != (int) strlen(cookie) || strncmp(cookie, rcookie, n)) {
+ rfbLog("accept_openssl: cookie from ssl_helper failed. %d\n", n);
+ if (errno != 0) {
+ rfbLogPerror("read");
+ }
+ if (db) fprintf(stderr, "'%s' '%s'\n", cookie, rcookie);
+ close(vsock);
+
+ kill(pid, SIGTERM);
+ waitpid(pid, &status, WNOHANG);
+ return;
+ }
+ if (db) fprintf(stderr, "accept_openssl: cookie good: %s\n", cookie);
+
+ rfbLog("SSL: handshake with helper process succeeded.\n");
+
+ openssl_last_helper_pid = pid;
+ ssh_helper_pid(pid, vsock);
+ client = rfbNewClient(screen, vsock);
+ openssl_last_helper_pid = 0;
+ if (client) {
+ if (db) fprintf(stderr, "accept_openssl: client %p\n", (void *) client);
+ } else {
+ rfbLog("accept_openssl: rfbNewClient failed.\n");
+ close(vsock);
+
+ kill(pid, SIGTERM);
+ waitpid(pid, &status, WNOHANG);
+ return;
+ }
+}
+
+static void ssl_timeout (int sig) {
+ fprintf(stderr, "sig: %d, ssh_init timed out.\n", sig);
+ exit(1);
+}
+
+static int ssl_init(int csock, int ssock) {
+ unsigned char *sid = (unsigned char *) "x11vnc SID";
+ char *name;
+ int db = 0, rc, err;
+
+ if (db) fprintf(stderr, "ssl_init: %d %d\n", csock, ssock);
+ ssl = SSL_new(ctx);
+ if (ssl == NULL) {
+ fprintf(stderr, "SSL_new failed\n");
+ return 0;
+ }
+
+ SSL_set_session_id_context(ssl, sid, strlen((char *)sid));
+
+ if (! SSL_set_fd(ssl, ssock)) {
+ fprintf(stderr, "SSL_set_fd failed\n");
+ return 0;
+ }
+
+ SSL_set_accept_state(ssl);
+
+ name = get_remote_host(ssock);
+
+ while (1) {
+ if (db) fprintf(stderr, "calling SSL_accept...\n");
+
+ signal(SIGALRM, ssl_timeout);
+ alarm(20);
+
+ rc = SSL_accept(ssl);
+ err = SSL_get_error(ssl, rc);
+
+ alarm(0);
+ signal(SIGALRM, SIG_DFL);
+
+ if (db) fprintf(stderr, "SSL_accept %d/%d\n", rc, err);
+ if (err == SSL_ERROR_NONE) {
+ break;
+ } else if (err == SSL_ERROR_WANT_READ) {
+ if (db) fprintf(stderr, "got SSL_ERROR_WANT_READ\n");
+ rfbLog("SSL: ssh_helper: SSL_accept() failed for: %s\n",
+ name);
+ return 0;
+
+ } else if (err == SSL_ERROR_WANT_WRITE) {
+ if (db) fprintf(stderr, "got SSL_ERROR_WANT_WRITE\n");
+ rfbLog("SSL: ssh_helper: SSL_accept() failed for: %s\n",
+ name);
+ return 0;
+ } else if (err == SSL_ERROR_SYSCALL) {
+ if (db) fprintf(stderr, "got SSL_ERROR_SYSCALL\n");
+ rfbLog("SSL: ssh_helper: SSL_accept() failed for: %s\n",
+ name);
+ return 0;
+ } else if (rc < 0) {
+ rfbLog("SSL: ssh_helper: SSL_accept() fatal: %d\n",
+ rc);
+ return 0;
+ }
+ }
+
+ rfbLog("SSL: ssh_helper: SSL_accept() succeeded for: %s\n", name);
+ free(name);
+
+ return 1;
+}
+
+static void ssl_xfer_debug(int csock, int ssock) {
+ char buf[2048];
+ int sz = 2048, n, m, status;
+ pid_t pid = fork();
+ int db = 1;
+
+ /* this is for testing, no SSL just socket redir */
+ if (pid < 0) {
+ exit(1);
+ }
+ if (pid) {
+ if (db) fprintf(stderr, "ssl_xfer start: %d -> %d\n", csock, ssock);
+
+ while (1) {
+ n = read(csock, buf, sz);
+ if (n == 0 || (n < 0 && errno != EINTR) ) {
+ break;
+ } else if (n > 0) {
+ m = write(ssock, buf, n);
+ if (m != n) {
+ if (db) fprintf(stderr, "ssl_xfer bad write: %d -> %d | %d/%d\n", csock, ssock, m, n);
+ break;
+ }
+
+ }
+ }
+ kill(pid, SIGTERM);
+ waitpid(pid, &status, WNOHANG);
+ if (db) fprintf(stderr, "ssl_xfer done: %d -> %d\n", csock, ssock);
+
+ } else {
+ if (db) fprintf(stderr, "ssl_xfer start: %d <- %d\n", csock, ssock);
+
+ while (1) {
+ n = read(ssock, buf, sz);
+ if (n == 0 || (n < 0 && errno != EINTR) ) {
+ break;
+ } else if (n > 0) {
+ m = write(csock, buf, n);
+ if (m != n) {
+ if (db) fprintf(stderr, "ssl_xfer bad write: %d <- %d | %d/%d\n", csock, ssock, m, n);
+ break;
+ }
+ }
+ }
+ if (db) fprintf(stderr, "ssl_xfer done: %d <- %d\n", csock, ssock);
+
+ }
+ close(csock);
+ close(ssock);
+ exit(0);
+}
+
+#define BSIZE 16384
+static void ssl_xfer(int csock, int ssock) {
+ int db = 0, check_pending, fdmax, nfd, n, err;
+ char cbuf[BSIZE], sbuf[BSIZE];
+ int cptr, sptr, c_rd, c_wr, s_rd, s_wr;
+ fd_set rd, wr;
+ struct timeval tv;
+
+ if (db) {
+ ssl_xfer_debug(csock, ssock);
+ return;
+ }
+
+ /*
+ * csock: clear text socket with libvncserver. "C"
+ * ssock: ssl data socket with remote vnc viewer. "S"
+ *
+ * cbuf[] is data from csock that we have read but not passed on to ssl
+ * sbuf[] is data from ssl that we have read but not passed on to csock
+ */
+
+ if (csock > ssock) {
+ fdmax = csock;
+ } else {
+ fdmax = ssock;
+ }
+
+ c_rd = 1; /* clear text (libvncserver) socket open for reading */
+ c_wr = 1; /* clear text (libvncserver) socket open for writing */
+ s_rd = 1; /* ssl data (remote client) socket open for reading */
+ s_wr = 1; /* ssl data (remote client) socket open for writing */
+
+ cptr = 0; /* offsets into BSIZE buffers */
+ sptr = 0;
+
+ while (1) {
+ int c_to_s, s_to_c;
+
+ if ( s_wr && (c_rd || cptr > 0) ) {
+ /*
+ * S is writable and
+ * C is readable or some cbuf data remaining
+ */
+ c_to_s = 1;
+ } else {
+ c_to_s = 0;
+ }
+
+ if ( c_wr && (s_rd || sptr > 0) ) {
+ /*
+ * C is writable and
+ * S is readable or some sbuf data remaining
+ */
+ s_to_c = 1;
+ } else {
+ s_to_c = 0;
+ }
+
+ if (! c_to_s && ! s_to_c) {
+ /*
+ * nothing can be sent either direction.
+ * break out of the loop to finish all work.
+ */
+ break;
+ }
+
+ /* set up the fd sets for the two sockets for read & write: */
+
+ FD_ZERO(&rd);
+
+ if (c_rd && cptr < BSIZE) {
+ /* we could read more from C since cbuf is not full */
+ FD_SET(csock, &rd);
+ }
+ if (s_rd) {
+ /*
+ * we could read more from S since sbuf not full,
+ * OR ssl is waiting for more BIO to be able to
+ * read and we have some C data still buffered.
+ */
+ if (sptr < BSIZE || (cptr > 0 && SSL_want_read(ssl))) {
+ FD_SET(ssock, &rd);
+ }
+ }
+
+ FD_ZERO(&wr);
+
+ if (c_wr && sptr > 0) {
+ /* we could write more to C since sbuf is not empty */
+ FD_SET(csock, &wr);
+ }
+ if (s_wr) {
+ /*
+ * we could write more to S since cbuf not empty,
+ * OR ssl is waiting for more BIO to be able
+ * write and we haven't filled up sbuf yet.
+ */
+ if (cptr > 0 || (sptr < BSIZE && SSL_want_write(ssl))) {
+ FD_SET(ssock, &wr);
+ }
+ }
+
+ tv.tv_sec = 20;
+ tv.tv_usec = 0;
+
+ /* do the select, repeat if interrupted */
+ do {
+ nfd = select(fdmax+1, &rd, &wr, NULL, &tv);
+ } while (nfd < 0 && errno == EINTR);
+
+ if (nfd < 0) {
+ fprintf(stderr, "select error: %d\n", nfd);
+ perror("select");
+ /* connection finished */
+ return;
+ }
+
+ if (nfd == 0) {
+ fprintf(stderr, "timeout\n");
+ /* connection finished */
+ return;
+ }
+
+ /* used to see if SSL_pending() should be checked: */
+ check_pending = 0;
+
+ if (c_wr && FD_ISSET(csock, &wr)) {
+
+ /* try to write some of our sbuf to C: */
+ n = write(csock, sbuf, sptr);
+
+ if (n < 0) {
+ if (errno != EINTR) {
+ /* connection finished */
+ return;
+ }
+ /* proceed */
+ } else if (n == 0) {
+ /* connection finished XXX double check */
+ return;
+ } else {
+ /* shift over the data in sbuf by n */
+ memmove(sbuf, sbuf + n, sptr - n);
+ if (sptr == BSIZE) {
+ check_pending = 1;
+ }
+ sptr -= n;
+
+ if (! s_rd && sptr == 0) {
+ /* finished sending last of sbuf */
+ shutdown(csock, SHUT_WR);
+ c_wr = 0;
+ }
+ }
+ }
+
+ if (s_wr) {
+ if ((cptr > 0 && FD_ISSET(ssock, &wr)) ||
+ (SSL_want_read(ssl) && FD_ISSET(ssock, &rd))) {
+
+ /* try to write some of our cbuf to S: */
+
+ n = SSL_write(ssl, cbuf, cptr);
+ err = SSL_get_error(ssl, n);
+
+ if (err == SSL_ERROR_NONE) {
+ /* shift over the data in cbuf by n */
+ memmove(cbuf, cbuf + n, cptr - n);
+ cptr -= n;
+
+ if (! c_rd && cptr == 0 && s_wr) {
+ /* finished sending last cbuf */
+ SSL_shutdown(ssl);
+ s_wr = 0;
+ }
+
+ } else if (err == SSL_ERROR_WANT_WRITE
+ || err == SSL_ERROR_WANT_READ
+ || err == SSL_ERROR_WANT_X509_LOOKUP) {
+
+ ; /* proceed */
+
+ } else if (err == SSL_ERROR_SYSCALL) {
+ if (n < 0 && errno != EINTR) {
+ /* connection finished */
+ return;
+ }
+ /* proceed */
+ } else if (err == SSL_ERROR_ZERO_RETURN) {
+ /* S finished */
+ s_rd = 0;
+ s_wr = 0;
+ } else if (err == SSL_ERROR_SSL) {
+ /* connection finished */
+ return;
+ }
+ }
+ }
+
+ if (c_rd && FD_ISSET(csock, &rd)) {
+
+ /* try to read some data from C into our cbuf */
+
+ n = read(csock, cbuf + cptr, BSIZE - cptr);
+
+ if (n < 0) {
+ if (errno != EINTR) {
+ /* connection finished */
+ return;
+ }
+ /* proceed */
+ } else if (n == 0) {
+ /* C is EOF */
+ c_rd = 0;
+ if (cptr == 0 && s_wr) {
+ /* and no more in cbuf to send */
+ SSL_shutdown(ssl);
+ s_wr = 0;
+ }
+ } else {
+ /* good */
+ cptr += n;
+ }
+ }
+
+ if (s_rd) {
+ if ((sptr < BSIZE && FD_ISSET(ssock, &rd)) ||
+ (SSL_want_write(ssl) && FD_ISSET(ssock, &wr)) ||
+ (check_pending && SSL_pending(ssl))) {
+
+ /* try to read some data from S into our sbuf */
+
+ n = SSL_read(ssl, sbuf + sptr, BSIZE - sptr);
+ err = SSL_get_error(ssl, n);
+
+ if (err == SSL_ERROR_NONE) {
+ /* good */
+ sptr += n;
+
+ } else if (err == SSL_ERROR_WANT_WRITE
+ || err == SSL_ERROR_WANT_READ
+ || err == SSL_ERROR_WANT_X509_LOOKUP) {
+
+ ; /* proceed */
+
+ } else if (err == SSL_ERROR_SYSCALL) {
+ if (n < 0) {
+ if(errno != EINTR) {
+ /* connection finished */
+ return;
+ }
+ /* proceed */
+ } else {
+ /* S finished */
+ s_rd = 0;
+ s_wr = 0;
+ }
+ } else if (err == SSL_ERROR_ZERO_RETURN) {
+ /* S is EOF */
+ s_rd = 0;
+ if (cptr == 0 && s_wr) {
+ /* and no more in cbuf to send */
+ SSL_shutdown(ssl);
+ s_wr = 0;
+ }
+ if (sptr == 0 && c_wr) {
+ /* and no more in sbuf to send */
+ shutdown(csock, SHUT_WR);
+ c_wr = 0;
+ }
+ } else if (err == SSL_ERROR_SSL) {
+ /* connection finished */
+ return;
+ }
+ }
+ }
+ }
+}
+
+void check_openssl(void) {
+ fd_set fds;
+ struct timeval tv;
+ int nfds;
+
+if (0) fprintf(stderr, "check_openssl()\n");
+
+ if (! use_openssl || openssl_sock < 0) {
+ return;
+ }
+
+ FD_ZERO(&fds);
+ FD_SET(openssl_sock, &fds);
+
+ tv.tv_sec = 0;
+ tv.tv_usec = 0;
+
+ nfds = select(openssl_sock+1, &fds, NULL, NULL, &tv);
+
+ if (nfds <= 0) {
+ return;
+ }
+ accept_openssl();
+}
+
+#define MSZ 4096
+static void init_prng(void) {
+ int db = 0, bytes;
+ char file[MSZ];
+
+ RAND_file_name(file, MSZ);
+
+ rfbLog("RAND_file_name: %s\n", file);
+
+ bytes = RAND_load_file(file, -1);
+ if (db) fprintf(stderr, "bytes read: %d\n", bytes);
+
+ bytes += RAND_load_file("/dev/urandom", 64);
+ if (db) fprintf(stderr, "bytes read: %d\n", bytes);
+
+ if (bytes > 0) {
+ if (! quiet) {
+ rfbLog("initialized PRNG with %d random bytes.\n",
+ bytes);
+ }
+ return;
+ }
+
+ bytes += RAND_load_file("/dev/random", 8);
+ if (db) fprintf(stderr, "bytes read: %d\n", bytes);
+ if (! quiet) {
+ rfbLog("initialized PRNG with %d random bytes.\n", bytes);
+ }
+}
+#endif /* FORK_OK */
+#endif /* LIBVNCSERVER_HAVE_LIBSSL */
+
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-22 06:04:58 +0000