/* -- sslhelper.c -- */ #include "x11vnc.h" #include "inet.h" #include "cleanup.h" #include "screen.h" #include "scan.h" #include "connections.h" #include "sslcmds.h" #include "unixpw.h" #define OPENSSL_INETD 1 #define OPENSSL_VNC 2 #define OPENSSL_HTTPS 3 #define OPENSSL_REVERSE 4 #define DO_DH 0 #if LIBVNCSERVER_HAVE_FORK #if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID #define FORK_OK #endif #endif int openssl_sock = -1; int openssl_port_num = 0; int https_sock = -1; pid_t openssl_last_helper_pid = 0; char *openssl_last_ip = NULL; static char *certret = NULL; static int certret_fd = -1; static mode_t omode; char *certret_str = NULL; static char *dhret = NULL; static int dhret_fd = -1; char *dhret_str = NULL; char *new_dh_params = NULL; void raw_xfer(int csock, int s_in, int s_out); #if !LIBVNCSERVER_HAVE_LIBSSL int openssl_present(void) {return 0;} static void badnews(void) { use_openssl = 0; use_stunnel = 0; rfbLog("** not compiled with libssl OpenSSL support **\n"); clean_up_exit(1); } void openssl_init(int isclient) {badnews();} void openssl_port(void) {badnews();} void https_port(void) {badnews();} void check_openssl(void) {if (use_openssl) badnews();} void check_https(void) {if (use_openssl) badnews();} void ssl_helper_pid(pid_t pid, int sock) {badnews(); sock = pid;} void accept_openssl(int mode, int presock) {mode = 0; presock = 0; badnews();} char *find_openssl_bin(void) {badnews(); return NULL;} char *get_saved_pem(char *string, int create) {badnews(); return NULL;} #else /* * This is because on older systems both zlib.h and ssl.h define * 'free_func' nothing we do below (currently) induces an external * dependency on 'free_func'. */ #define free_func my_jolly_little_free_func #include #include #include int openssl_present(void); void openssl_init(int isclient); void openssl_port(void); void check_openssl(void); void check_https(void); void ssl_helper_pid(pid_t pid, int sock); void accept_openssl(int mode, int presock); char *find_openssl_bin(void); char *get_saved_pem(char *string, int create); static SSL_CTX *ctx = NULL; static RSA *rsa_512 = NULL; static RSA *rsa_1024 = NULL; static SSL *ssl = NULL; static X509_STORE *revocation_store = NULL; static void init_prng(void); static void sslerrexit(void); static char *get_input(char *tag, char **in); static char *create_tmp_pem(char *path, int prompt); static int ssl_init(int s_in, int s_out, int skip_vnc_tls); static void ssl_xfer(int csock, int s_in, int s_out, int is_https); #ifndef FORK_OK void openssl_init(int isclient) { 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(); if (err) { char str[256]; ERR_error_string(err, str); fprintf(stderr, "ssl error: %s\n", str); } clean_up_exit(1); } char *get_saved_pem(char *save, int create) { char *s = NULL, *path, *cdir, *tmp; int prompt = 0, len; struct stat sbuf; if (! save) { rfbLog("get_saved_pem: save string is null.\n"); clean_up_exit(1); } if (strstr(save, "SAVE_PROMPT") == save) { prompt = 1; s = save + strlen("SAVE_PROMPT"); } else if (strstr(save, "SAVE_NOPROMPT") == save) { set_env("GENCERT_NOPROMPT", "1"); s = save + strlen("SAVE_NOPROMPT"); } else if (strstr(save, "SAVE") == save) { s = save + strlen("SAVE"); } else { rfbLog("get_saved_pem: invalid save string: %s\n", save); clean_up_exit(1); } if (strchr(s, '/')) { rfbLog("get_saved_pem: invalid save string: %s\n", s); clean_up_exit(1); } cdir = get_Cert_dir(NULL, &tmp); if (! cdir || ! tmp) { rfbLog("get_saved_pem: could not find Cert dir.\n"); clean_up_exit(1); } len = strlen(cdir) + strlen("/server.pem") + strlen(s) + 1; path = (char *) malloc(len); sprintf(path, "%s/server%s.pem", cdir, s); if (stat(path, &sbuf) != 0) { char *new = NULL; if (create) { if (inetd || opts_bg) { set_env("GENCERT_NOPROMPT", "1"); } new = create_tmp_pem(path, prompt); if (!getenv("X11VNC_SSL_NO_PASSPHRASE") && !inetd && !opts_bg) { sslEncKey(new, 0); } } return new; } if (! quiet) { char line[1024]; int on = 0; FILE *in = fopen(path, "r"); if (in != NULL) { rfbLog("\n"); rfbLog("Using SSL Certificate:\n"); fprintf(stderr, "\n"); while (fgets(line, 1024, in) != NULL) { if (strstr(line, "BEGIN CERTIFICATE")) { on = 1; } if (on) { fprintf(stderr, "%s", line); } if (strstr(line, "END CERTIFICATE")) { on = 0; } if (strstr(line, "PRIVATE KEY")) { on = 0; } } fprintf(stderr, "\n"); fclose(in); } } return strdup(path); } static char *get_input(char *tag, char **in) { char line[1024], *str; if (! tag || ! in || ! *in) { return NULL; } fprintf(stderr, "%s:\n [%s] ", tag, *in); if (fgets(line, 1024, stdin) == NULL) { rfbLog("could not read stdin!\n"); rfbLogPerror("fgets"); clean_up_exit(1); } if ((str = strrchr(line, '\n')) != NULL) { *str = '\0'; } str = lblanks(line); if (!strcmp(str, "")) { return *in; } else { return strdup(line); } } char *find_openssl_bin(void) { char *path, *exe, *p, *gp; struct stat sbuf; int found_openssl = 0; char extra[] = ":/usr/bin:/bin:/usr/sbin:/usr/local/bin" ":/usr/local/sbin:/usr/sfw/bin"; gp = getenv("PATH"); if (! gp) { fprintf(stderr, "could not find openssl(1) program in PATH.\n"); return NULL; } path = (char *) malloc(strlen(gp) + strlen(extra) + 1); strcpy(path, gp); strcat(path, extra); /* 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) { fprintf(stderr, "could not find openssl(1) program in PATH.\n"); fprintf(stderr, "(also checked: %s)\n", extra); return NULL; } return exe; } /* uses /usr/bin/openssl to create a tmp cert */ static char *create_tmp_pem(char *pathin, int prompt) { pid_t pid, pidw; FILE *in, *out; char cnf[] = "/tmp/x11vnc-cnf.XXXXXX"; char pem[] = "/tmp/x11vnc-pem.XXXXXX"; char str[8*1024], line[1024], *exe; int cnf_fd, pem_fd, status, show_cert = 1; char *days; char *C, *L, *OU, *O, *CN, *EM; char tmpl[] = "[ req ]\n" "prompt = no\n" "default_bits = 2048\n" "encrypt_key = yes\n" "distinguished_name = req_dn\n" "x509_extensions = cert_type\n" "\n" "[ req_dn ]\n" "countryName=%s\n" "localityName=%s\n" "organizationalUnitName=%s\n" "organizationName=%s\n" "commonName=%s\n" "emailAddress=%s\n" "\n" "[ cert_type ]\n" "nsCertType = server\n" ; C = strdup("AU"); L = strdup(UT.sysname ? UT.sysname : "unknown-os"); snprintf(line, 1024, "%s-%f", UT.nodename ? UT.nodename : "unknown-node", dnow()); line[1024-1] = '\0'; OU = strdup(line); O = strdup("x11vnc"); if (pathin) { snprintf(line, 1024, "x11vnc-SELF-SIGNED-CERT-%d", getpid()); } else { snprintf(line, 1024, "x11vnc-SELF-SIGNED-TEMPORARY-CERT-%d", getpid()); } line[1024-1] = '\0'; CN = strdup(line); EM = strdup("x11vnc@server.nowhere"); /* ssl */ if (no_external_cmds || !cmd_ok("ssl")) { rfbLog("create_tmp_pem: cannot run external commands.\n"); return NULL; } rfbLog("\n"); if (pathin) { rfbLog("Creating a self-signed PEM certificate...\n"); } else { rfbLog("Creating a temporary, self-signed PEM certificate...\n"); } rfbLog("\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 or you take the extra steps to sign it\n"); rfbLog("with a CA key. However, it will prevent passive network\n"); rfbLog("sniffing.\n"); rfbLog("\n"); rfbLog("The cert inside -----BEGIN CERTIFICATE-----\n"); rfbLog(" ....\n"); rfbLog(" -----END CERTIFICATE-----\n"); rfbLog("printed below may be used on the VNC viewer-side to\n"); rfbLog("authenticate this server for this session. See the -ssl\n"); rfbLog("help output and the FAQ for how to create a permanent\n"); rfbLog("server certificate.\n"); rfbLog("\n"); exe = find_openssl_bin(); if (! exe) { return NULL; } /* create template file with our made up stuff: */ if (prompt) { fprintf(stderr, "\nReply to the following prompts to set" " your Certificate parameters.\n"); fprintf(stderr, "(press Enter to accept the default in [...], " "or type in the value you want)\n\n"); C = get_input("CountryName", &C); L = get_input("LocalityName", &L); OU = get_input("OrganizationalUnitName", &OU); O = get_input("OrganizationalName", &O); CN = get_input("CommonName", &CN); EM = get_input("EmailAddress", &EM); } sprintf(str, tmpl, C, L, OU, O, CN, EM); cnf_fd = mkstemp(cnf); pem_fd = mkstemp(pem); if (cnf_fd < 0 || pem_fd < 0) { return NULL; } close(pem_fd); write(cnf_fd, str, strlen(str)); close(cnf_fd); if (pathin) { days = "365"; } else { days = "30"; } /* 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", "-days", days, "-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; } #if DO_DH /* make DH parameters */ pid = fork(); if (pid < 0) { return NULL; } else if (pid == 0) { int i; for (i=0; i<256; i++) { close(i); } /* rather slow at 1024 */ 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); #endif unlink(cnf); free(exe); if (pathin != NULL) { char *q, *pathcrt = strdup(pathin); FILE *crt = NULL; int on = 0; q = strrchr(pathcrt, '/'); if (q) { q = strstr(q, ".pem"); if (q) { *(q+1) = 'c'; *(q+2) = 'r'; *(q+3) = 't'; crt = fopen(pathcrt, "w"); } } if (crt == NULL) { rfbLog("could not open: %s\n", pathcrt); rfbLogPerror("fopen"); return NULL; } out = fopen(pathin, "w"); chmod(pathin, 0600); if (out == NULL) { rfbLog("could not open: %s\n", pathin); rfbLogPerror("fopen"); fclose(crt); return NULL; } in = fopen(pem, "r"); if (in == NULL) { rfbLog("could not open: %s\n", pem); rfbLogPerror("fopen"); fclose(out); fclose(crt); unlink(pathin); unlink(pathcrt); return NULL; } while (fgets(line, 1024, in) != NULL) { if (strstr(line, "BEGIN CERTIFICATE")) { on = 1; } fprintf(out, "%s", line); if (on) { fprintf(crt, "%s", line); if (!quiet) { fprintf(stderr, "%s", line); } } if (strstr(line, "END CERTIFICATE")) { on = 0; } if (strstr(line, "PRIVATE KEY")) { on = 0; } } fclose(in); fclose(out); fclose(crt); } if (show_cert) { char cmd[100]; if (inetd) { sprintf(cmd, "openssl x509 -text -in '%s' 1>&2", pem); } else { sprintf(cmd, "openssl x509 -text -in '%s'", pem); } fprintf(stderr, "\n"); system(cmd); fprintf(stderr, "\n"); } if (pathin) { unlink(pem); return strdup(pathin); } else { return strdup(pem); } } static int pem_passwd_callback(char *buf, int size, int rwflag, void *userdata) { char *q, line[1024]; if (! buf) { exit(1); } fprintf(stderr, "\nA passphrase is needed to unlock an OpenSSL " "private key (PEM file).\n"); fprintf(stderr, "Enter passphrase> "); system("stty -echo"); if(fgets(line, 1024, stdin) == NULL) { fprintf(stdout, "\n"); system("stty echo"); exit(1); } system("stty echo"); fprintf(stdout, "\n\n"); q = strrchr(line, '\n'); if (q) { *q = '\0'; } line[1024 - 1] = '\0'; strncpy(buf, line, size); buf[size - 1] = '\0'; if (0) rwflag = 0; /* compiler warning. */ if (0) userdata = 0; /* compiler warning. */ return strlen(buf); } static int appendfile(FILE *out, char *infile) { char line[1024]; FILE *in; if (! infile) { rfbLog("appendfile: null infile.\n"); return 0; } if (! out) { rfbLog("appendfile: null out handle.\n"); return 0; } in = fopen(infile, "r"); if (in == NULL) { rfbLog("appendfile: %s\n", infile); rfbLogPerror("fopen"); return 0; } while (fgets(line, 1024, in) != NULL) { fprintf(out, "%s", line); } fclose(in); return 1; } static char *get_ssl_verify_file(char *str_in) { char *p, *str, *cdir, *tmp; char *tfile, *tfile2; FILE *file; struct stat sbuf; int count = 0, fd; if (! str_in) { rfbLog("get_ssl_verify_file: no filename\n"); exit(1); } if (stat(str_in, &sbuf) == 0) { /* assume he knows what he is doing. */ return str_in; } cdir = get_Cert_dir(NULL, &tmp); if (! cdir || ! tmp) { rfbLog("get_ssl_verify_file: invalid cert-dir.\n"); exit(1); } tfile = (char *) malloc(strlen(tmp) + 1024); tfile2 = (char *) malloc(strlen(tmp) + 1024); sprintf(tfile, "%s/sslverify-load-%d.crts.XXXXXX", tmp, getpid()); fd = mkstemp(tfile); if (fd < 0) { rfbLog("get_ssl_verify_file: %s\n", tfile); rfbLogPerror("mkstemp"); exit(1); } close(fd); file = fopen(tfile, "w"); chmod(tfile, 0600); if (file == NULL) { rfbLog("get_ssl_verify_file: %s\n", tfile); rfbLogPerror("fopen"); exit(1); } str = strdup(str_in); p = strtok(str, ","); while (p) { if (!strcmp(p, "CA")) { sprintf(tfile2, "%s/CA/cacert.pem", cdir); if (! appendfile(file, tfile2)) { unlink(tfile); exit(1); } rfbLog("sslverify: loaded %s\n", tfile2); count++; } else if (!strcmp(p, "clients")) { DIR *dir; struct dirent *dp; sprintf(tfile2, "%s/clients", cdir); dir = opendir(tfile2); if (! dir) { rfbLog("get_ssl_verify_file: %s\n", tfile2); rfbLogPerror("opendir"); unlink(tfile); exit(1); } while ( (dp = readdir(dir)) != NULL) { char *n = dp->d_name; char *q = strstr(n, ".crt"); if (! q || strlen(q) != strlen(".crt")) { continue; } if (strlen(n) > 512) { continue; } sprintf(tfile2, "%s/clients/%s", cdir, n); if (! appendfile(file, tfile2)) { unlink(tfile); exit(1); } rfbLog("sslverify: loaded %s\n", tfile2); count++; } closedir(dir); } else { if (strlen(p) > 512) { unlink(tfile); exit(1); } sprintf(tfile2, "%s/clients/%s.crt", cdir, p); if (stat(tfile2, &sbuf) != 0) { sprintf(tfile2, "%s/clients/%s", cdir, p); } if (! appendfile(file, tfile2)) { unlink(tfile); exit(1); } rfbLog("sslverify: loaded %s\n", tfile2); count++; } p = strtok(NULL, ","); } fclose(file); free(tfile2); free(str); rfbLog("sslverify: using %d client certs in\n", count); rfbLog("sslverify: %s\n", tfile); return tfile; } /* based on mod_ssl */ static int crl_callback(X509_STORE_CTX *callback_ctx) { X509_STORE_CTX store_ctx; X509_OBJECT obj; X509_NAME *subject; X509_NAME *issuer; X509 *xs; X509_CRL *crl; X509_REVOKED *revoked; EVP_PKEY *pubkey; long serial; BIO *bio; int i, n, rc; char *cp, *cp2; ASN1_TIME *t; /* Determine certificate ingredients in advance */ xs = X509_STORE_CTX_get_current_cert(callback_ctx); subject = X509_get_subject_name(xs); issuer = X509_get_issuer_name(xs); /* Try to retrieve a CRL corresponding to the _subject_ of * the current certificate in order to verify it's integrity. */ memset((char *)&obj, 0, sizeof(obj)); X509_STORE_CTX_init(&store_ctx, revocation_store, NULL, NULL); rc=X509_STORE_get_by_subject(&store_ctx, X509_LU_CRL, subject, &obj); X509_STORE_CTX_cleanup(&store_ctx); crl=obj.data.crl; if(rc>0 && crl) { /* Log information about CRL * (A little bit complicated because of ASN.1 and BIOs...) */ bio=BIO_new(BIO_s_mem()); BIO_printf(bio, "lastUpdate: "); ASN1_UTCTIME_print(bio, X509_CRL_get_lastUpdate(crl)); BIO_printf(bio, ", nextUpdate: "); ASN1_UTCTIME_print(bio, X509_CRL_get_nextUpdate(crl)); n=BIO_pending(bio); cp=malloc(n+1); n=BIO_read(bio, cp, n); cp[n]='\0'; BIO_free(bio); cp2=X509_NAME_oneline(subject, NULL, 0); rfbLog("CA CRL: Issuer: %s, %s\n", cp2, cp); OPENSSL_free(cp2); free(cp); /* Verify the signature on this CRL */ pubkey=X509_get_pubkey(xs); if(X509_CRL_verify(crl, pubkey)<=0) { rfbLog("Invalid signature on CRL\n"); X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE); X509_OBJECT_free_contents(&obj); if(pubkey) EVP_PKEY_free(pubkey); return 0; /* Reject connection */ } if(pubkey) EVP_PKEY_free(pubkey); /* Check date of CRL to make sure it's not expired */ t=X509_CRL_get_nextUpdate(crl); if(!t) { rfbLog("Found CRL has invalid nextUpdate field\n"); X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD); X509_OBJECT_free_contents(&obj); return 0; /* Reject connection */ } if(X509_cmp_current_time(t)<0) { rfbLog("Found CRL is expired - " "revoking all certificates until you get updated CRL\n"); X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_CRL_HAS_EXPIRED); X509_OBJECT_free_contents(&obj); return 0; /* Reject connection */ } X509_OBJECT_free_contents(&obj); } /* Try to retrieve a CRL corresponding to the _issuer_ of * the current certificate in order to check for revocation. */ memset((char *)&obj, 0, sizeof(obj)); X509_STORE_CTX_init(&store_ctx, revocation_store, NULL, NULL); rc=X509_STORE_get_by_subject(&store_ctx, X509_LU_CRL, issuer, &obj); X509_STORE_CTX_cleanup(&store_ctx); crl=obj.data.crl; if(rc>0 && crl) { /* Check if the current certificate is revoked by this CRL */ n=sk_X509_REVOKED_num(X509_CRL_get_REVOKED(crl)); for(i=0; iserialNumber, X509_get_serialNumber(xs)) == 0) { serial=ASN1_INTEGER_get(revoked->serialNumber); cp=X509_NAME_oneline(issuer, NULL, 0); rfbLog("Certificate with serial %ld (0x%lX) " "revoked per CRL from issuer %s\n", serial, serial, cp); OPENSSL_free(cp); X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_CERT_REVOKED); X509_OBJECT_free_contents(&obj); return 0; /* Reject connection */ } } X509_OBJECT_free_contents(&obj); } return 1; /* Accept connection */ } static int verify_callback(int ok, X509_STORE_CTX *callback_ctx) { if (!ssl_verify) { rfbLog("CRL_check: skipped.\n"); return ok; } if (!ssl_crl) { rfbLog("CRL_check: skipped.\n"); return ok; } if (!ok) { rfbLog("CRL_check: client cert is already rejected.\n"); return ok; } if (revocation_store) { if (crl_callback(callback_ctx)) { rfbLog("CRL_check: succeeded.\n"); return 1; } else { rfbLog("CRL_check: did not pass.\n"); return 0; } } /* NOTREACHED */ return 1; } #define rfbSecTypeAnonTls 18 #define rfbSecTypeVencrypt 19 #define rfbVencryptPlain 256 #define rfbVencryptTlsNone 257 #define rfbVencryptTlsVnc 258 #define rfbVencryptTlsPlain 259 #define rfbVencryptX509None 260 #define rfbVencryptX509Vnc 261 #define rfbVencryptX509Plain 262 static int vencrypt_selected = 0; static int anontls_selected = 0; static int ssl_client_mode = 0; static int switch_to_anon_dh(void); void openssl_init(int isclient) { int db = 0, tmp_pem = 0, do_dh; FILE *in; double ds; long mode; static int first = 1; do_dh = DO_DH; if (enc_str != NULL) { if (first) { init_prng(); } first = 0; return; } if (! quiet) { rfbLog("\n"); rfbLog("Initializing SSL (%s connect mode).\n", isclient ? "client":"server"); } if (first) { 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(); first = 0; } if (isclient) { ssl_client_mode = 1; } else { ssl_client_mode = 0; } if (ssl_client_mode) { if (db) fprintf(stderr, "SSLv23_client_method()\n"); ctx = SSL_CTX_new( SSLv23_client_method() ); } else { if (db) fprintf(stderr, "SSLv23_server_method()\n"); 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); #define ssl_cache 0 #if ssl_cache SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH); SSL_CTX_set_timeout(ctx, 300); #else SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF); SSL_CTX_set_timeout(ctx, 1); #endif ds = dnow(); if (! openssl_pem) { openssl_pem = create_tmp_pem(NULL, 0); if (! openssl_pem) { rfbLog("openssl_init: could not create temporary," " self-signed PEM.\n"); clean_up_exit(1); } tmp_pem = 1; } else if (!strcmp(openssl_pem, "ANON")) { if (ssl_verify) { rfbLog("openssl_init: Anonymous Diffie-Hellman cannot" " be used in -sslverify mode.\n"); clean_up_exit(1); } if (ssl_crl) { rfbLog("openssl_init: Anonymous Diffie-Hellman cannot" " be used in -sslCRL mode.\n"); clean_up_exit(1); } /* n.b. new ctx */ if (!switch_to_anon_dh()) { rfbLog("openssl_init: Anonymous Diffie-Hellman setup" " failed.\n"); clean_up_exit(1); } } else if (strstr(openssl_pem, "SAVE") == openssl_pem) { openssl_pem = get_saved_pem(openssl_pem, 1); if (! openssl_pem) { rfbLog("openssl_init: could not create or open" " saved PEM: %s\n", openssl_pem); clean_up_exit(1); } tmp_pem = 0; } rfbLog("using PEM %s %.3fs\n", openssl_pem, dnow() - ds); SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_callback); 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 (strcmp(openssl_pem, "ANON")) { 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); openssl_pem = NULL; } if (ssl_crl) { struct stat sbuf; X509_LOOKUP *lookup; if (stat(ssl_crl, &sbuf) != 0) { rfbLog("openssl_init: -sslCRL does not exist %s.\n", ssl_crl ? ssl_crl : "null"); rfbLogPerror("stat"); clean_up_exit(1); } revocation_store = X509_STORE_new(); if (!revocation_store) { rfbLog("openssl_init: X509_STORE_new failed.\n"); sslerrexit(); } if (! S_ISDIR(sbuf.st_mode)) { lookup = X509_STORE_add_lookup(revocation_store, X509_LOOKUP_file()); if (!lookup) { rfbLog("openssl_init: X509_STORE_add_lookup failed.\n"); sslerrexit(); } if (!X509_LOOKUP_load_file(lookup, ssl_crl, X509_FILETYPE_PEM)) { rfbLog("openssl_init: X509_LOOKUP_load_file failed.\n"); sslerrexit(); } } else { lookup = X509_STORE_add_lookup(revocation_store, X509_LOOKUP_hash_dir()); if (!lookup) { rfbLog("openssl_init: X509_STORE_add_lookup failed.\n"); sslerrexit(); } if (!X509_LOOKUP_add_dir(lookup, ssl_crl, X509_FILETYPE_PEM)) { rfbLog("openssl_init: X509_LOOKUP_add_dir failed.\n"); sslerrexit(); } } rfbLog("loaded CRL file: %s\n", ssl_crl); } if (ssl_verify) { struct stat sbuf; char *file; int lvl; file = get_ssl_verify_file(ssl_verify); if (!file || stat(file, &sbuf) != 0) { rfbLog("openssl_init: -sslverify does not exist %s.\n", file ? file : "null"); rfbLogPerror("stat"); clean_up_exit(1); } if (! S_ISDIR(sbuf.st_mode)) { if (! SSL_CTX_load_verify_locations(ctx, file, NULL)) { rfbLog("openssl_init: SSL_CTX_load_verify_" "locations() failed.\n"); sslerrexit(); } } else { if (! SSL_CTX_load_verify_locations(ctx, NULL, file)) { rfbLog("openssl_init: SSL_CTX_load_verify_" "locations() failed.\n"); sslerrexit(); } } lvl = SSL_VERIFY_FAIL_IF_NO_PEER_CERT|SSL_VERIFY_PEER; if (ssl_crl == NULL) { SSL_CTX_set_verify(ctx, lvl, NULL); } else { SSL_CTX_set_verify(ctx, lvl, verify_callback); } if (strstr(file, "tmp/sslverify-load-")) { /* temporary file */ unlink(file); } } else { SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL); } rfbLog("\n"); } void openssl_port(void) { int sock, shutdown = 0; static int port = 0; static in_addr_t iface = INADDR_ANY; int db = 0; if (! screen) { rfbLog("openssl_port: no screen!\n"); clean_up_exit(1); } if (inetd) { ssl_initialized = 1; return; } 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); #if LIBVNCSERVER_HAS_SHUTDOWNSOCKETS rfbShutdownSockets(screen); #endif } sock = rfbListenOnTCPPort(port, iface); if (sock < 0) { rfbLog("openssl_port: could not reopen port %d\n", port); clean_up_exit(1); } rfbLog("openssl_port: listen on port/sock %d/%d\n", port, sock); if (!quiet) { announce(port, 1, NULL); } openssl_sock = sock; openssl_port_num = port; ssl_initialized = 1; } void https_port(void) { int sock; static int port = 0; static in_addr_t iface = INADDR_ANY; int db = 0; /* as openssl_port above: open a listening socket for pure https: */ if (https_port_num < 0) { return; } if (! screen) { rfbLog("https_port: no screen!\n"); clean_up_exit(1); } if (screen->listenInterface) { iface = screen->listenInterface; } if (https_port_num == 0) { https_port_num = find_free_port(5801, 5851); } if (https_port_num <= 0) { rfbLog("https_port: could not find port %d\n", https_port_num); clean_up_exit(1); } port = https_port_num; sock = rfbListenOnTCPPort(port, iface); if (sock < 0) { rfbLog("https_port: could not open port %d\n", port); clean_up_exit(1); } if (db) fprintf(stderr, "https_port: listen on port/sock %d/%d\n", port, sock); https_sock = sock; } 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(); free_tiles(); } /* utility to keep track of existing helper processes: */ void ssl_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, status; static int db = 0; if (first) { for (i=0; i < HPSIZE; i++) { helpers[i] = 0; sockets[i] = 0; } if (getenv("SSL_HELPER_PID_DB")) { db = 1; } first = 0; } if (pid == 0) { /* killall or waitall */ for (i=0; i < HPSIZE; i++) { if (helpers[i] == 0) { sockets[i] = -1; continue; } if (kill(helpers[i], 0) == 0) { int kret = -2; pid_t wret; if (sock != -2) { if (sockets[i] >= 0) { close(sockets[i]); } kret = kill(helpers[i], SIGTERM); if (kret == 0) { usleep(20 * 1000); } } #if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID wret = waitpid(helpers[i], &status, WNOHANG); if (db) fprintf(stderr, "waitpid(%d)\n", helpers[i]); if (db) fprintf(stderr, " waitret1=%d\n", wret); if (kret == 0 && wret != helpers[i]) { int k; for (k=0; k < 10; k++) { usleep(100 * 1000); wret = waitpid(helpers[i], &status, WNOHANG); if (db) fprintf(stderr, " waitret2=%d\n", wret); if (wret == helpers[i]) { break; } } } #endif if (sock == -2) { continue; } } helpers[i] = 0; sockets[i] = -1; } return; } if (db) fprintf(stderr, "ssl_helper_pid(%d, %d)\n", pid, sock); /* add (or delete for sock == -1) */ set = 0; empty = -1; for (i=0; i < HPSIZE; i++) { if (helpers[i] == pid) { if (sock == -1) { #if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID pid_t wret; wret = waitpid(helpers[i], &status, WNOHANG); if (db) fprintf(stderr, "waitpid(%d) 2\n", helpers[i]); if (db) fprintf(stderr, " waitret1=%d\n", wret); #endif helpers[i] = 0; } sockets[i] = sock; set = 1; } else if (empty == -1 && helpers[i] == 0) { empty = i; } } if (set || sock == -1) { return; /* done */ } /* now try to store */ if (empty >= 0) { helpers[empty] = pid; sockets[empty] = sock; return; } for (i=0; i < HPSIZE; i++) { if (helpers[i] == 0) { continue; } /* clear out stale pids: */ 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; } } static int is_ssl_readable(int s_in, time_t last_https, char *last_get, int mode) { int nfd, db = 0; struct timeval tv; fd_set rd; if (getenv("ACCEPT_OPENSSL_DEBUG")) { db = atoi(getenv("ACCEPT_OPENSSL_DEBUG")); } /* * we'll do a select() on s_in for reading. this is not an * absolute proof that SSL_read is ready (XXX use SSL utility). */ tv.tv_sec = 2; tv.tv_usec = 0; if (mode == OPENSSL_INETD) { /* * https via inetd is icky because x11vnc is restarted * for each socket (and some clients send requests * rapid fire). */ tv.tv_sec = 6; } /* * increase the timeout if we know HTTP traffic has occurred * recently: */ if (time(NULL) < last_https + 30) { tv.tv_sec = 10; if (last_get && strstr(last_get, "VncViewer")) { tv.tv_sec = 5; } } if (getenv("X11VNC_HTTPS_VS_VNC_TIMEOUT")) { tv.tv_sec = atoi(getenv("X11VNC_HTTPS_VS_VNC_TIMEOUT")); } if (db) fprintf(stderr, "tv_sec: %d - %s\n", (int) tv.tv_sec, last_get); FD_ZERO(&rd); FD_SET(s_in, &rd); do { nfd = select(s_in+1, &rd, NULL, NULL, &tv); } while (nfd < 0 && errno == EINTR); if (db) fprintf(stderr, "https nfd: %d\n", nfd); if (nfd <= 0 || ! FD_ISSET(s_in, &rd)) { return 0; } return 1; } #define ABSIZE 16384 static int watch_for_http_traffic(char *buf_a, int *n_a, int raw_sock) { int is_http, err, n, n2; char *buf; int db = 0; /* * sniff the first couple bytes of the stream and try to see * if it is http or not. if we read them OK, we must read the * rest of the available data otherwise we may deadlock. * what has been read is returned in buf_a and n_a. * *buf_a is ABSIZE+1 long and zeroed. */ if (getenv("ACCEPT_OPENSSL_DEBUG")) { db = atoi(getenv("ACCEPT_OPENSSL_DEBUG")); } if (! buf_a || ! n_a) { return 0; } buf = (char *) calloc((ABSIZE+1), 1); *n_a = 0; if (enc_str && !strcmp(enc_str, "none")) { n = read(raw_sock, buf, 2); err = SSL_ERROR_NONE; } else { n = SSL_read(ssl, buf, 2); err = SSL_get_error(ssl, n); } if (err != SSL_ERROR_NONE || n < 2) { if (n > 0) { strncpy(buf_a, buf, n); *n_a = n; } if (db) fprintf(stderr, "watch_for_http_traffic ssl err: %d/%d\n", err, n); return -1; } /* look for GET, HEAD, POST, CONNECT */ is_http = 0; if (!strncmp("GE", buf, 2)) { is_http = 1; } else if (!strncmp("HE", buf, 2)) { is_http = 1; } else if (!strncmp("PO", buf, 2)) { is_http = 1; } else if (!strncmp("CO", buf, 2)) { is_http = 1; } if (db) fprintf(stderr, "watch_for_http_traffic read: '%s' %d\n", buf, n); /* * better read all we can and fwd it along to avoid blocking * in ssl_xfer(). */ if (enc_str && !strcmp(enc_str, "none")) { n2 = read(raw_sock, buf + n, ABSIZE - n); } else { n2 = SSL_read(ssl, buf + n, ABSIZE - n); } if (n2 >= 0) { n += n2; } *n_a = n; if (db) fprintf(stderr, "watch_for_http_traffic readmore: %d\n", n2); if (n > 0) { memcpy(buf_a, buf, n); } if (db > 1) { fprintf(stderr, "watch_for_http_traffic readmore: "); write(2, buf_a, *n_a); fprintf(stderr, "\n"); } if (db) fprintf(stderr, "watch_for_http_traffic return: %d\n", is_http); return is_http; } static int csock_timeout_sock = -1; static void csock_timeout (int sig) { rfbLog("sig: %d, csock_timeout.\n", sig); if (csock_timeout_sock >= 0) { close(csock_timeout_sock); csock_timeout_sock = -1; } } #define PROXY_HACK 0 #if PROXY_HACK static int wait_conn(int sock) { int conn; struct sockaddr_in addr; #ifdef __hpux int addrlen = sizeof(addr); #else socklen_t addrlen = sizeof(addr); #endif signal(SIGALRM, csock_timeout); csock_timeout_sock = sock; alarm(15); conn = accept(sock, (struct sockaddr *)&addr, &addrlen); alarm(0); signal(SIGALRM, SIG_DFL); return conn; } /* no longer used */ int proxy_hack(int vncsock, int listen, int s_in, int s_out, char *cookie, int mode) { int sock1, db = 0; char reply[] = "HTTP/1.1 200 OK\r\n" "Content-Type: octet-stream\r\n" "Pragma: no-cache\r\n\r\n"; char reply0[] = "HTTP/1.0 200 OK\r\n" "Content-Type: octet-stream\r\n" "Content-Length: 9\r\n" "Pragma: no-cache\r\n\r\nGO_AHEAD\n"; rfbLog("SSL: accept_openssl: detected https proxied connection" " request.\n"); if (getenv("ACCEPT_OPENSSL_DEBUG")) { db = atoi(getenv("ACCEPT_OPENSSL_DEBUG")); } SSL_write(ssl, reply0, strlen(reply0)); SSL_shutdown(ssl); SSL_shutdown(ssl); close(s_in); close(s_out); SSL_free(ssl); if (mode == OPENSSL_VNC) { listen = openssl_sock; } else if (mode == OPENSSL_HTTPS) { listen = https_sock; } else { /* inetd */ return 0; } sock1 = wait_conn(listen); if (csock_timeout_sock < 0 || sock1 < 0) { close(sock1); return 0; } if (db) fprintf(stderr, "got applet input sock1: %d\n", sock1); if (! ssl_init(sock1, sock1, 0)) { if (db) fprintf(stderr, "ssl_init FAILED\n"); exit(1); } SSL_write(ssl, reply, strlen(reply)); { char *buf; int n = 0, ptr = 0; buf = (char *) calloc((8192+1), 1); while (ptr < 8192) { n = SSL_read(ssl, buf + ptr, 8192 - ptr); if (n > 0) { ptr += n; } if (db) fprintf(stderr, "buf: '%s'\n", buf); if (strstr(buf, "\r\n\r\n")) { break; } } } if (cookie) { write(vncsock, cookie, strlen(cookie)); } ssl_xfer(vncsock, sock1, sock1, 0); return 1; } #endif /* PROXY_HACK */ static int check_ssl_access(char *addr) { static char *save_allow_once = NULL; static time_t time_allow_once = 0; /* due to "Fetch Cert" activities for SSL really need to "allow twice" */ if (allow_once != NULL) { save_allow_once = strdup(allow_once); time_allow_once = time(NULL); } else if (save_allow_once != NULL) { if (getenv("X11VNC_NO_SSL_ALLOW_TWICE")) { ; } else if (time(NULL) < time_allow_once + 30) { /* give them 30 secs to check and save the fetched cert. */ allow_once = save_allow_once; rfbLog("SSL: Permitting 30 sec grace period for allowonce.\n"); rfbLog("SSL: Set X11VNC_NO_SSL_ALLOW_TWICE=1 to disable.\n"); } save_allow_once = NULL; time_allow_once = 0; } return check_access(addr); } static int write_exact(int sock, char *buf, int len); static int read_exact(int sock, char *buf, int len); /* XXX not in rfb.h: */ void rfbClientSendString(rfbClientPtr cl, char *reason); static int finish_auth(rfbClientPtr client, char *type) { int security_result, ret; ret = 0; if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "finish_auth type=%s\n", type); if (!strcmp(type, "None")) { security_result = 0; /* success */ if (write_exact(client->sock, (char *) &security_result, 4)) { ret = 1; } rfbLog("finish_auth: using auth 'None'\n"); client->state = RFB_INITIALISATION; } else if (!strcmp(type, "Vnc")) { RAND_bytes(client->authChallenge, CHALLENGESIZE); if (write_exact(client->sock, (char *) &client->authChallenge, CHALLENGESIZE)) { ret = 1; } rfbLog("finish_auth: using auth 'Vnc', sent challenge.\n"); client->state = RFB_AUTHENTICATION; } else if (!strcmp(type, "Plain")) { if (!unixpw) { rfbLog("finish_auth: *Plain not allowed outside unixpw mode.\n"); ret = 0; } else { char *un, *pw; int unlen, pwlen; if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "*Plain begin: onHold=%d client=%p unixpw_client=%p\n", client->onHold, (void *) client, (void *) unixpw_client); if (!read_exact(client->sock, (char *)&unlen, 4)) goto fail; unlen = Swap32IfLE(unlen); if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "unlen: %d\n", unlen); if (!read_exact(client->sock, (char *)&pwlen, 4)) goto fail; pwlen = Swap32IfLE(pwlen); if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "pwlen: %d\n", pwlen); un = (char *) malloc(unlen+1); memset(un, 0, unlen+1); pw = (char *) malloc(pwlen+2); memset(pw, 0, pwlen+2); if (!read_exact(client->sock, un, unlen)) goto fail; if (!read_exact(client->sock, pw, pwlen)) goto fail; if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "*Plain: %d %d '%s' ... \n", unlen, pwlen, un); strcat(pw, "\n"); if (unixpw_verify(un, pw)) { security_result = 0; /* success */ if (write_exact(client->sock, (char *) &security_result, 4)) { ret = 1; unixpw_verify_screen(un, pw); } client->onHold = FALSE; client->state = RFB_INITIALISATION; } if (ret == 0) { rfbClientSendString(client, "unixpw failed"); } memset(un, 0, unlen+1); memset(pw, 0, pwlen+2); free(un); free(pw); } } else { rfbLog("finish_auth: unknown sub-type: %s\n", type); ret = 0; } fail: return ret; } static int finish_vencrypt_auth(rfbClientPtr client, int subtype) { if (subtype == rfbVencryptTlsNone || subtype == rfbVencryptX509None) { return finish_auth(client, "None"); } else if (subtype == rfbVencryptTlsVnc || subtype == rfbVencryptX509Vnc) { return finish_auth(client, "Vnc"); } else if (subtype == rfbVencryptTlsPlain || subtype == rfbVencryptX509Plain) { return finish_auth(client, "Plain"); } else { rfbLog("finish_vencrypt_auth: unknown sub-type: %d\n", subtype); return 0; } } void accept_openssl(int mode, int presock) { int sock = -1, listen = -1, cport, csock, vsock; int peerport = 0; int status, n, i, db = 0; struct sockaddr_in addr; #ifdef __hpux int addrlen = sizeof(addr); #else socklen_t addrlen = sizeof(addr); #endif rfbClientPtr client; pid_t pid; char uniq[] = "_evilrats_"; char cookie[256], rcookie[256], *name = NULL; int vencrypt_sel = 0; int anontls_sel = 0; static time_t last_https = 0; static char last_get[256]; static int first = 1; unsigned char *rb; openssl_last_helper_pid = 0; /* zero buffers for use below. */ for (i=0; i<256; i++) { if (first) { last_get[i] = '\0'; } cookie[i] = '\0'; rcookie[i] = '\0'; } first = 0; if (getenv("ACCEPT_OPENSSL_DEBUG")) { db = atoi(getenv("ACCEPT_OPENSSL_DEBUG")); } /* do INETD, VNC, or HTTPS cases (result is client socket or pipe) */ if (mode == OPENSSL_INETD) { ssl_initialized = 1; } else if (mode == OPENSSL_VNC) { sock = accept(openssl_sock, (struct sockaddr *)&addr, &addrlen); if (sock < 0) { rfbLog("SSL: accept_openssl: accept connection failed\n"); rfbLogPerror("accept"); if (ssl_no_fail) { clean_up_exit(1); } return; } listen = openssl_sock; } else if (mode == OPENSSL_REVERSE) { sock = presock; if (sock < 0) { rfbLog("SSL: accept_openssl: connection failed\n"); if (ssl_no_fail) { clean_up_exit(1); } return; } listen = -1; } else if (mode == OPENSSL_HTTPS) { sock = accept(https_sock, (struct sockaddr *)&addr, &addrlen); if (sock < 0) { rfbLog("SSL: accept_openssl: accept connection failed\n"); rfbLogPerror("accept"); if (ssl_no_fail) { clean_up_exit(1); } return; } listen = https_sock; } if (db) fprintf(stderr, "SSL: accept_openssl: sock: %d\n", sock); if (openssl_last_ip) { free(openssl_last_ip); openssl_last_ip = NULL; } if (mode == OPENSSL_INETD) { openssl_last_ip = get_remote_host(fileno(stdin)); } else { openssl_last_ip = get_remote_host(sock); } if (!check_ssl_access(openssl_last_ip)) { rfbLog("SSL: accept_openssl: denying client %s\n", openssl_last_ip); rfbLog("SSL: accept_openssl: does not match -allow (or other reason).\n"); close(sock); sock = -1; if (ssl_no_fail) { clean_up_exit(1); } return; } /* now make a listening socket for child to connect back to us by: */ cport = find_free_port(20000, 0); if (! cport) { rfbLog("SSL: accept_openssl: could not find open port.\n"); close(sock); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } return; } if (db) fprintf(stderr, "accept_openssl: cport: %d\n", cport); csock = rfbListenOnTCPPort(cport, htonl(INADDR_LOOPBACK)); if (csock < 0) { rfbLog("SSL: accept_openssl: could not listen on port %d.\n", cport); close(sock); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } return; } if (db) fprintf(stderr, "accept_openssl: csock: %d\n", csock); fflush(stderr); /* * make a simple cookie to id the child socket, not foolproof * but hard to guess exactly (just worrying about local lusers * here, since we use INADDR_LOOPBACK). */ rb = (unsigned char *) calloc(6, 1); RAND_bytes(rb, 6); sprintf(cookie, "RB=%d%d%d%d%d%d/%f%f/%p", rb[0], rb[1], rb[2], rb[3], rb[4], rb[5], dnow() - x11vnc_start, x11vnc_start, (void *)rb); if (mode != OPENSSL_INETD) { name = get_remote_host(sock); peerport = get_remote_port(sock); } else { openssl_last_ip = get_remote_host(fileno(stdin)); peerport = get_remote_port(fileno(stdin)); if (openssl_last_ip) { name = strdup(openssl_last_ip); } else { name = strdup("unknown"); } } if (name) { if (mode == OPENSSL_INETD) { rfbLog("SSL: (inetd) spawning helper process " "to handle: %s:%d\n", name, peerport); } else { rfbLog("SSL: spawning helper process to handle: " "%s:%d\n", name, peerport); } free(name); name = NULL; } if (certret) { free(certret); } if (certret_str) { free(certret_str); certret_str = NULL; } certret = strdup("/tmp/x11vnc-certret.XXXXXX"); omode = umask(077); certret_fd = mkstemp(certret); umask(omode); if (certret_fd < 0) { free(certret); certret = NULL; certret_fd = -1; } if (dhret) { free(dhret); } if (dhret_str) { free(dhret_str); dhret_str = NULL; } dhret = strdup("/tmp/x11vnc-dhret.XXXXXX"); omode = umask(077); dhret_fd = mkstemp(dhret); umask(omode); if (dhret_fd < 0) { free(dhret); dhret = NULL; dhret_fd = -1; } /* now fork the child to handle the SSL: */ pid = fork(); if (pid < 0) { rfbLog("SSL: accept_openssl: could not fork.\n"); rfbLogPerror("fork"); close(sock); close(csock); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } return; } else if (pid == 0) { int s_in, s_out, httpsock = -1; int vncsock; int i, have_httpd = 0; int f_in = fileno(stdin); int f_out = fileno(stdout); int skip_vnc_tls = mode == OPENSSL_HTTPS ? 1 : 0; if (db) fprintf(stderr, "helper pid in: %d %d %d %d\n", f_in, f_out, sock, listen); /* reset all handlers to default (no interrupted() calls) */ unset_signals(); /* close all non-essential fd's */ for (i=0; i<256; i++) { if (mode == OPENSSL_INETD) { if (i == f_in || i == f_out) { continue; } } if (i == sock) { continue; } if (i == 2) { continue; } close(i); } /* * sadly, we are a long lived child and so the large * framebuffer memory areas will soon differ from parent. * try to free as much as possible. */ lose_ram(); /* now connect back to parent socket: */ vncsock = rfbConnectToTcpAddr("127.0.0.1", cport); if (vncsock < 0) { rfbLog("SSL: ssl_helper[%d]: could not connect" " back to: %d\n", getpid(), cport); exit(1); } if (db) fprintf(stderr, "vncsock %d\n", vncsock); /* try to initialize SSL with the remote client */ if (mode == OPENSSL_INETD) { s_in = fileno(stdin); s_out = fileno(stdout); } else { s_in = s_out = sock; } if (! ssl_init(s_in, s_out, skip_vnc_tls)) { close(vncsock); exit(1); } if (vencrypt_selected != 0) { char *tbuf; tbuf = (char *) malloc(strlen(cookie) + 100); sprintf(tbuf, "%s,VENCRYPT=%d,%s", uniq, vencrypt_selected, cookie); write(vncsock, tbuf, strlen(cookie)); goto wrote_cookie; } else if (anontls_selected != 0) { char *tbuf; tbuf = (char *) malloc(strlen(cookie) + 100); sprintf(tbuf, "%s,ANONTLS=%d,%s", uniq, anontls_selected, cookie); write(vncsock, tbuf, strlen(cookie)); goto wrote_cookie; } /* * things get messy below since we are trying to do * *both* VNC and Java applet httpd through the same * SSL socket. */ if (! screen) { close(vncsock); exit(1); } if (screen->httpListenSock >= 0 && screen->httpPort > 0) { have_httpd = 1; } if (screen->httpListenSock == -2) { have_httpd = 1; } if (mode == OPENSSL_HTTPS && ! have_httpd) { rfbLog("SSL: accept_openssl[%d]: no httpd socket for " "-https mode\n", getpid()); close(vncsock); exit(1); } if (have_httpd) { int n = 0, is_http = 0; int hport = screen->httpPort; char *iface = NULL; char *buf, *tbuf; buf = (char *) calloc((ABSIZE+1), 1); tbuf = (char *) calloc((2*ABSIZE+1), 1); if (mode == OPENSSL_HTTPS) { /* * for this mode we know it is HTTP traffic * so we skip trying to guess. */ is_http = 1; n = 0; goto connect_to_httpd; } /* * Check if there is stuff to read from remote end * if so it is likely a GET or HEAD. */ if (! is_ssl_readable(s_in, last_https, last_get, mode)) { goto write_cookie; } /* * read first 2 bytes to try to guess. sadly, * the user is often pondering a "non-verified * cert" dialog for a long time before the GET * is ever sent. So often we timeout here. */ if (db) fprintf(stderr, "watch_for_http_traffic\n"); is_http = watch_for_http_traffic(buf, &n, s_in); if (is_http < 0 || is_http == 0) { /* * error or http not detected, fall back * to normal VNC socket. */ if (db) fprintf(stderr, "is_http err: %d n: %d\n", is_http, n); write(vncsock, cookie, strlen(cookie)); if (n > 0) { write(vncsock, buf, n); } goto wrote_cookie; } if (db) fprintf(stderr, "is_http: %d n: %d\n", is_http, n); if (db) fprintf(stderr, "buf: '%s'\n", buf); if (strstr(buf, "/request.https.vnc.connection")) { char reply[] = "HTTP/1.0 200 OK\r\n" "Content-Type: octet-stream\r\n" "Connection: Keep-Alive\r\n" "Pragma: no-cache\r\n\r\n"; /* * special case proxy coming thru https * instead of a direct SSL connection. */ rfbLog("Handling VNC request via https GET. [%d]\n", getpid()); rfbLog("-- %s\n", buf); if (strstr(buf, "/reverse.proxy")) { char *buf2; int n, ptr; SSL_write(ssl, reply, strlen(reply)); buf2 = (char *) calloc((8192+1), 1); n = 0; ptr = 0; while (ptr < 8192) { n = SSL_read(ssl, buf2 + ptr, 1); if (n > 0) { ptr += n; } if (db) fprintf(stderr, "buf2: '%s'\n", buf2); if (strstr(buf2, "\r\n\r\n")) { break; } } free(buf2); } goto write_cookie; } else if (strstr(buf, "/check.https.proxy.connection")) { char reply[] = "HTTP/1.0 200 OK\r\n" "Connection: close\r\n" "Content-Type: octet-stream\r\n" "Pragma: no-cache\r\n\r\n"; rfbLog("Handling Check HTTPS request via https GET. [%d]\n", getpid()); rfbLog("-- %s\n", buf); SSL_write(ssl, reply, strlen(reply)); SSL_shutdown(ssl); strcpy(tbuf, uniq); strcat(tbuf, cookie); write(vncsock, tbuf, strlen(tbuf)); close(vncsock); exit(0); } connect_to_httpd: /* * Here we go... no turning back. we have to * send failure to parent and close socket to have * http processed at all in a timely fashion... */ /* send the failure tag: */ strcpy(tbuf, uniq); if (https_port_redir < 0 || (strstr(buf, "PORT=") || strstr(buf, "port="))) { char *q = strstr(buf, "Host:"); int fport = 443, match = 0; char num[16]; if (q && strstr(q, "\n")) { q += strlen("Host:") + 1; while (*q != '\n') { int p; if (*q == ':' && sscanf(q, ":%d", &p) == 1) { if (p > 0 && p < 65536) { fport = p; match = 1; break; } } q++; } } if (!match || !https_port_redir) { int p; if (sscanf(buf, "PORT=%d,", &p) == 1) { if (p > 0 && p < 65536) { fport = p; } } else if (sscanf(buf, "port=%d,", &p) == 1) { if (p > 0 && p < 65536) { fport = p; } } } sprintf(num, "HP=%d,", fport); strcat(tbuf, num); } if (strstr(buf, "HTTP/") != NULL) { char *q, *str; /* * Also send back the GET line for heuristics. * (last_https, get file). */ str = strdup(buf); q = strstr(str, "HTTP/"); if (q != NULL) { *q = '\0'; strcat(tbuf, str); } free(str); } /* * Also send the cookie to pad out the number of * bytes to more than the parent wants to read. * Since this is the failure case, it does not * matter that we send more than strlen(cookie). */ strcat(tbuf, cookie); write(vncsock, tbuf, strlen(tbuf)); usleep(150*1000); if (db) fprintf(stderr, "close vncsock: %d\n", vncsock); close(vncsock); /* now, finally, connect to the libvncserver httpd: */ if (screen->listenInterface == htonl(INADDR_ANY) || screen->listenInterface == htonl(INADDR_NONE)) { iface = "127.0.0.1"; } else { struct in_addr in; in.s_addr = screen->listenInterface; iface = inet_ntoa(in); } if (iface == NULL || !strcmp(iface, "")) { iface = "127.0.0.1"; } if (db) fprintf(stderr, "iface: %s:%d\n", iface, hport); usleep(150*1000); httpsock = rfbConnectToTcpAddr(iface, hport); if (httpsock < 0) { /* UGH, after all of that! */ rfbLog("Could not connect to httpd socket!\n"); exit(1); } if (db) fprintf(stderr, "ssl_helper[%d]: httpsock: %d %d\n", getpid(), httpsock, n); /* * send what we read to httpd, and then connect * the rest of the SSL session to it: */ if (n > 0) { if (db) fprintf(stderr, "sending http buffer httpsock: %d\n'%s'\n", httpsock, buf); write(httpsock, buf, n); } ssl_xfer(httpsock, s_in, s_out, is_http); exit(0); } /* * ok, back from the above https mess, simply send the * cookie back to the parent (who will attach us to * libvncserver), and connect the rest of the SSL session * to it. */ write_cookie: write(vncsock, cookie, strlen(cookie)); wrote_cookie: ssl_xfer(vncsock, s_in, s_out, 0); exit(0); } /* parent here */ if (mode != OPENSSL_INETD) { close(sock); } if (db) fprintf(stderr, "helper process is: %d\n", pid); /* accept connection from our child. */ signal(SIGALRM, csock_timeout); csock_timeout_sock = csock; alarm(20); vsock = accept(csock, (struct sockaddr *)&addr, &addrlen); alarm(0); signal(SIGALRM, SIG_DFL); close(csock); if (vsock < 0) { rfbLog("SSL: accept_openssl: connection from ssl_helper FAILED.\n"); rfbLogPerror("accept"); kill(pid, SIGTERM); waitpid(pid, &status, WNOHANG); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } if (certret_fd >= 0) { close(certret_fd); certret_fd = -1; } if (certret) { unlink(certret); } if (dhret_fd >= 0) { close(dhret_fd); dhret_fd = -1; } if (dhret) { unlink(dhret); } return; } if (db) fprintf(stderr, "accept_openssl: vsock: %d\n", vsock); n = read(vsock, rcookie, strlen(cookie)); if (n < 0 && errno != 0) { rfbLogPerror("read"); } if (certret) { struct stat sbuf; sbuf.st_size = 0; if (certret_fd >= 0 && stat(certret, &sbuf) == 0 && sbuf.st_size > 0) { certret_str = (char *) calloc(sbuf.st_size+1, 1); read(certret_fd, certret_str, sbuf.st_size); close(certret_fd); certret_fd = -1; } if (certret_fd >= 0) { close(certret_fd); certret_fd = -1; } unlink(certret); if (certret_str && strstr(certret_str, "NOCERT") == certret_str) { free(certret_str); certret_str = NULL; } if (0 && certret_str) { fprintf(stderr, "certret_str[%d]:\n%s\n", (int) sbuf.st_size, certret_str); } } if (dhret) { struct stat sbuf; sbuf.st_size = 0; if (dhret_fd >= 0 && stat(dhret, &sbuf) == 0 && sbuf.st_size > 0) { dhret_str = (char *) calloc(sbuf.st_size+1, 1); read(dhret_fd, dhret_str, sbuf.st_size); close(dhret_fd); dhret_fd = -1; } if (dhret_fd >= 0) { close(dhret_fd); dhret_fd = -1; } unlink(dhret); if (dhret_str && strstr(dhret_str, "NOCERT") == dhret_str) { free(dhret_str); dhret_str = NULL; } if (dhret_str) { if (new_dh_params == NULL) { fprintf(stderr, "dhret_str[%d]:\n%s\n", (int) sbuf.st_size, dhret_str); new_dh_params = strdup(dhret_str); } } } if (0) { fprintf(stderr, "rcookie: %s\n", rcookie); fprintf(stderr, "cookie: %s\n", cookie); } if (strstr(rcookie, uniq) == rcookie) { char *q = strstr(rcookie, "RB="); if (q && strstr(cookie, q) == cookie) { vencrypt_sel = 0; anontls_sel = 0; q = strstr(rcookie, "VENCRYPT="); if (q && sscanf(q, "VENCRYPT=%d,", &vencrypt_sel) == 1) { if (vencrypt_sel != 0) { rfbLog("SSL: VENCRYPT mode=%d accepted.\n", vencrypt_sel); goto accept_client; } } q = strstr(rcookie, "ANONTLS="); if (q && sscanf(q, "ANONTLS=%d,", &anontls_sel) == 1) { if (anontls_sel != 0) { rfbLog("SSL: ANONTLS mode=%d accepted.\n", anontls_sel); goto accept_client; } } } } if (n != (int) strlen(cookie) || strncmp(cookie, rcookie, n)) { rfbLog("SSL: accept_openssl: cookie from ssl_helper FAILED. %d\n", n); if (db) fprintf(stderr, "'%s'\n'%s'\n", cookie, rcookie); close(vsock); if (strstr(rcookie, uniq) == rcookie) { int i; rfbLog("SSL: BUT WAIT! HTTPS for helper process succeeded. Good.\n"); if (mode != OPENSSL_HTTPS) { last_https = time(NULL); for (i=0; i<256; i++) { last_get[i] = '\0'; } strncpy(last_get, rcookie, 100); if (db) fprintf(stderr, "last_get: '%s'\n", last_get); } if (rcookie && strstr(rcookie, "VncViewer.class")) { rfbLog("\n"); rfbLog("***********************************************************\n"); rfbLog("SSL: WARNING CLIENT ASKED FOR NONEXISTENT 'VncViewer.class'\n"); rfbLog("SSL: USER NEEDS TO **RESTART** HIS WEB BROWSER.\n"); rfbLog("***********************************************************\n"); rfbLog("\n"); } ssl_helper_pid(pid, -2); if (https_port_redir) { double start; int origport = screen->port; int useport = screen->port; /* to expand $PORT correctly in index.vnc */ if (https_port_redir < 0) { char *q = strstr(rcookie, "HP="); if (q) { int p; if (sscanf(q, "HP=%d,", &p) == 1) { useport = p; } } } else { useport = https_port_redir; } screen->port = useport; if (origport != useport) { rfbLog("SSL: -httpsredir guess port: %d\n", screen->port); } start = dnow(); while (dnow() < start + 10.0) { rfbPE(10000); usleep(10000); waitpid(pid, &status, WNOHANG); if (kill(pid, 0) != 0) { rfbPE(10000); rfbPE(10000); break; } } screen->port = origport; rfbLog("SSL: guessing child https finished.\n"); ssl_helper_pid(0, -2); if (mode == OPENSSL_INETD) { clean_up_exit(1); } } else if (mode == OPENSSL_INETD) { double start; /* to expand $PORT correctly in index.vnc */ if (screen->port == 0) { int fd = fileno(stdin); if (getenv("X11VNC_INETD_PORT")) { screen->port = atoi(getenv( "X11VNC_INETD_PORT")); } else { int tport = get_local_port(fd); if (tport > 0) { screen->port = tport; } } } rfbLog("SSL: screen->port %d\n", screen->port); /* kludge for https fetch via inetd */ start = dnow(); while (dnow() < start + 10.0) { rfbPE(10000); usleep(10000); waitpid(pid, &status, WNOHANG); if (kill(pid, 0) != 0) { rfbPE(10000); rfbPE(10000); break; } } rfbLog("SSL: OPENSSL_INETD guessing " "child https finished.\n"); ssl_helper_pid(0, -2); clean_up_exit(1); } /* this will actually only get earlier https */ ssl_helper_pid(0, -2); return; } kill(pid, SIGTERM); waitpid(pid, &status, WNOHANG); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } return; } accept_client: if (db) fprintf(stderr, "accept_openssl: cookie good: %s\n", cookie); rfbLog("SSL: handshake with helper process succeeded.\n"); openssl_last_helper_pid = pid; ssl_helper_pid(pid, vsock); if (vnc_redirect) { vnc_redirect_sock = vsock; openssl_last_helper_pid = 0; return; } client = rfbNewClient(screen, vsock); openssl_last_helper_pid = 0; if (client) { if (db) fprintf(stderr, "accept_openssl: client %p\n", (void *) client); if (db) fprintf(stderr, "accept_openssl: new_client %p\n", (void *) screen->newClientHook); if (db) fprintf(stderr, "accept_openssl: new_client %p\n", (void *) new_client); if (mode == OPENSSL_INETD) { inetd_client = client; client->clientGoneHook = client_gone; } if (openssl_last_ip && strpbrk(openssl_last_ip, "0123456789") == openssl_last_ip) { client->host = strdup(openssl_last_ip); } if (vencrypt_sel != 0) { client->protocolMajorVersion = 3; client->protocolMinorVersion = 8; if (!finish_vencrypt_auth(client, vencrypt_sel)) { rfbCloseClient(client); } } else if (anontls_sel != 0) { client->protocolMajorVersion = 3; client->protocolMinorVersion = 8; rfbAuthNewClient(client); } } else { rfbLog("SSL: accept_openssl: rfbNewClient failed.\n"); close(vsock); kill(pid, SIGTERM); waitpid(pid, &status, WNOHANG); if (mode == OPENSSL_INETD || ssl_no_fail) { clean_up_exit(1); } return; } } static int read_exact(int sock, char *buf, int len) { int n, fail = 0; if (sock < 0) { return 0; } while (len > 0) { n = read(sock, buf, len); if (n > 0) { buf += n; len -= n; } else if (n == 0) { fail = 1; break; } else if (n < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) { usleep(10*1000); } else if (n < 0 && errno != EINTR) { fail = 1; break; } } if (fail) { return 0; } else { return 1; } } static int write_exact(int sock, char *buf, int len) { int n, fail = 0; if (sock < 0) { return 0; } while (len > 0) { n = write(sock, buf, len); if (n > 0) { buf += n; len -= n; } else if (n == 0) { fail = 1; break; } else if (n < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) { usleep(10*1000); } else if (n < 0 && errno != EINTR) { fail = 1; break; } } if (fail) { return 0; } else { return 1; } } static int add_anon_dh(void) { pid_t pid, pidw; char cnf[] = "/tmp/x11vnc-dh.XXXXXX"; char *infile = NULL; int status, cnf_fd; DH *dh; BIO *bio; FILE *in; double ds; /* * These are dh parameters (prime, generator), not dh keys. * Evidently it is ok for them to be publicly known. * openssl dhparam -out dh.out 1024 */ char *fixed_dh_params = "-----BEGIN DH PARAMETERS-----\n" "MIGHAoGBAL28w69ZnLYBvp8R2OeqtAIms+oatY19iBL4WhGI/7H1OMmkJjIe+OHs\n" "PXoJfe5ucrnvno7Xm+HJZYa1jnPGQuWoa/VJKXdVjYdJVNzazJKM2daKKcQA4GDc\n" "msFS5DxLbzUR5jy1n12K3EcbvpyFqDYVTJJXm7NuNuiWRfz3wTozAgEC\n" "-----END DH PARAMETERS-----\n"; if (dhparams_file != NULL) { infile = dhparams_file; rfbLog("add_anon_dh: using %s\n", dhparams_file); goto readin; } cnf_fd = mkstemp(cnf); if (cnf_fd < 0) { return 0; } infile = cnf; if (create_fresh_dhparams) { if (new_dh_params != NULL) { write(cnf_fd, new_dh_params, strlen(new_dh_params)); close(cnf_fd); } else { char *exe = find_openssl_bin(); struct stat sbuf; if (no_external_cmds || !cmd_ok("ssl")) { rfbLog("add_anon_dh: cannot run external commands.\n"); return 0; } close(cnf_fd); if (exe == NULL) { return 0; } ds = dnow(); pid = fork(); if (pid < 0) { return 0; } else if (pid == 0) { int i; for (i=0; i<256; i++) { if (i == 2) continue; close(i); } /* rather slow at 1024 */ execlp(exe, exe, "dhparam", "-out", cnf, "1024", (char *)0); exit(1); } pidw = waitpid(pid, &status, 0); if (pidw != pid) { return 0; } if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { ; } else { return 0; } rfbLog("add_anon_dh: created new DH params in %.3f secs\n", dnow() - ds); if (stat(cnf, &sbuf) == 0 && sbuf.st_size > 0) { /* save it to reuse during our process's lifetime: */ int d = open(cnf, O_RDONLY); if (d >= 0) { int n, len = sbuf.st_size; new_dh_params = (char *) calloc(len+1, 1); n = read(d, new_dh_params, len); close(d); if (n != len) { free(new_dh_params); new_dh_params = NULL; } else if (dhret != NULL) { d = open(dhret, O_WRONLY); if (d >= 0) { write(d, new_dh_params, strlen(new_dh_params)); close(d); } } } } } } else { write(cnf_fd, fixed_dh_params, strlen(fixed_dh_params)); close(cnf_fd); } readin: ds = dnow(); in = fopen(infile, "r"); if (in == NULL) { rfbLogPerror("fopen"); unlink(cnf); return 0; } bio = BIO_new_fp(in, BIO_CLOSE|BIO_FP_TEXT); if (! bio) { rfbLog("openssl_init: BIO_new_fp() failed.\n"); unlink(cnf); return 0; } dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL); if (dh == NULL) { rfbLog("openssl_init: PEM_read_bio_DHparams() failed.\n"); unlink(cnf); BIO_free(bio); return 0; } 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); unlink(cnf); return 1; } static int switch_to_anon_dh(void) { long mode; rfbLog("Using Anonymous Diffie-Hellman mode.\n"); rfbLog("WARNING: Anonymous Diffie-Hellman uses encryption but is\n"); rfbLog("WARNING: susceptible to a Man-In-The-Middle attack.\n"); if (ssl_client_mode) { ctx = SSL_CTX_new( SSLv23_client_method() ); } else { ctx = SSL_CTX_new( SSLv23_server_method() ); } if (ctx == NULL) { return 0; } if (ssl_client_mode) { return 1; } if (!SSL_CTX_set_cipher_list(ctx, "ADH:@STRENGTH")) { return 0; } if (!add_anon_dh()) { return 0; } 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); SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_callback); SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL); return 1; } static int anontls_dialog(int s_in, int s_out) { if (s_in || s_out) {} anontls_selected = 1; if (!switch_to_anon_dh()) { rfbLog("anontls: Anonymous Diffie-Hellman failed.\n"); return 0; } /* continue with SSL/TLS */ return 1; } /* * Using spec: * http://www.mail-archive.com/qemu-devel@nongnu.org/msg08681.html */ static int vencrypt_dialog(int s_in, int s_out) { char buf[256], buf2[256]; int subtypes[16]; int n, i, ival, ok, nsubtypes = 0; vencrypt_selected = 0; /* send version 0.2 */ buf[0] = 0; buf[1] = 2; if (!write_exact(s_out, buf, 2)) { close(s_in); close(s_out); return 0; } /* read client version 0.2 */ memset(buf, 0, sizeof(buf)); if (!read_exact(s_in, buf, 2)) { close(s_in); close(s_out); return 0; } rfbLog("vencrypt: received %d.%d client version.\n", (int) buf[0], (int) buf[1]); /* close 0.0 */ if (buf[0] == 0 && buf[1] == 0) { rfbLog("vencrypt: received 0.0 version, closing connection.\n"); close(s_in); close(s_out); return 0; } /* accept only 0.2 */ if (buf[0] != 0 || buf[1] != 2) { rfbLog("vencrypt: unsupported VeNCrypt version, closing connection.\n"); buf[0] = (char) 255; write_exact(s_out, buf, 1); close(s_in); close(s_out); return 0; } /* tell them OK */ buf[0] = 0; if (!write_exact(s_out, buf, 1)) { close(s_in); close(s_out); return 0; } if (getenv("X11VNC_ENABLE_VENCRYPT_PLAIN_LOGIN")) { vencrypt_enable_plain_login = atoi(getenv("X11VNC_ENABLE_VENCRYPT_PLAIN_LOGIN")); } /* load our list of sub-types: */ n = 0; if (!ssl_verify && vencrypt_kx != VENCRYPT_NODH) { if (screen->authPasswdData != NULL) { subtypes[n++] = rfbVencryptTlsVnc; } else { if (vencrypt_enable_plain_login && unixpw) { subtypes[n++] = rfbVencryptTlsPlain; } else { subtypes[n++] = rfbVencryptTlsNone; } } } if (vencrypt_kx != VENCRYPT_NOX509) { if (screen->authPasswdData != NULL) { subtypes[n++] = rfbVencryptX509Vnc; } else { if (vencrypt_enable_plain_login && unixpw) { subtypes[n++] = rfbVencryptX509Plain; } else { subtypes[n++] = rfbVencryptX509None; } } } nsubtypes = n; for (i = 0; i < nsubtypes; i++) { ((uint32_t *)buf)[i] = Swap32IfLE(subtypes[i]); } /* send number first: */ buf2[0] = (char) nsubtypes; if (!write_exact(s_out, buf2, 1)) { close(s_in); close(s_out); return 0; } /* and now the list: */ if (!write_exact(s_out, buf, 4*n)) { close(s_in); close(s_out); return 0; } /* read client's selection: */ if (!read_exact(s_in, (char *)&ival, 4)) { close(s_in); close(s_out); return 0; } ival = Swap32IfLE(ival); /* zero means no dice: */ if (ival == 0) { rfbLog("vencrypt: client selected no sub-type, closing connection.\n"); close(s_in); close(s_out); return 0; } /* check if he selected a valid one: */ ok = 0; for (i = 0; i < nsubtypes; i++) { if (ival == subtypes[i]) { ok = 1; } } if (!ok) { rfbLog("vencrypt: client selected invalid sub-type: %d\n", ival); close(s_in); close(s_out); return 0; } else { char *st = "unknown!!"; if (ival == rfbVencryptTlsNone) st = "rfbVencryptTlsNone"; if (ival == rfbVencryptTlsVnc) st = "rfbVencryptTlsVnc"; if (ival == rfbVencryptTlsPlain) st = "rfbVencryptTlsPlain"; if (ival == rfbVencryptX509None) st = "rfbVencryptX509None"; if (ival == rfbVencryptX509Vnc) st = "rfbVencryptX509Vnc"; if (ival == rfbVencryptX509Plain) st = "rfbVencryptX509Plain"; rfbLog("vencrypt: client selected sub-type: %d (%s)\n", ival, st); } vencrypt_selected = ival; /* not documented in spec, send OK: */ buf[0] = 1; if (!write_exact(s_out, buf, 1)) { close(s_in); close(s_out); return 0; } if (vencrypt_selected == rfbVencryptTlsNone || vencrypt_selected == rfbVencryptTlsVnc || vencrypt_selected == rfbVencryptTlsPlain) { /* these modes are Anonymous Diffie-Hellman */ if (!switch_to_anon_dh()) { rfbLog("vencrypt: Anonymous Diffie-Hellman failed.\n"); return 0; } } /* continue with SSL/TLS */ return 1; } static int check_vnc_tls_mode(int s_in, int s_out) { double waited = 0.0, dt = 0.01, start = dnow(); struct timeval tv; int input = 0, i, n, ok; int major, minor, sectype = -1; char *proto = "RFB 003.008\n"; char *stype = "unknown"; char buf[256]; vencrypt_selected = 0; anontls_selected = 0; if (vencrypt_mode == VENCRYPT_NONE && anontls_mode == ANONTLS_NONE) { /* only normal SSL */ return 1; } if (ssl_client_mode) { if (vencrypt_mode == VENCRYPT_FORCE || anontls_mode == ANONTLS_FORCE) { rfbLog("check_vnc_tls_mode: VENCRYPT_FORCE/ANONTLS_FORCE in client\n"); rfbLog("check_vnc_tls_mode: connect mode.\n"); /* this is OK, continue on below for dialog. */ } else { /* otherwise we must assume normal SSL (we send client hello) */ return 1; } } if (ssl_verify && vencrypt_mode != VENCRYPT_FORCE && anontls_mode == ANONTLS_FORCE) { rfbLog("check_vnc_tls_mode: Cannot use ANONTLS_FORCE with -sslverify (Anon DH only)\n"); /* fallback to normal SSL */ return 1; } while (waited < 1.1) { fd_set rfds; FD_ZERO(&rfds); FD_SET(s_in, &rfds); tv.tv_sec = 0; tv.tv_usec = 0; select(s_in+1, &rfds, NULL, NULL, &tv); if (FD_ISSET(s_in, &rfds)) { input = 1; break; } usleep((int) (1000 * 1000 * dt)); waited += dt; } rfbLog("check_vnc_tls_mode: waited: %f input: %s\n", dnow() - start, input ? "SSL Handshake" : "(future) RFB Handshake"); if (input) { /* got SSL client hello, can only assume normal SSL */ if (vencrypt_mode == VENCRYPT_FORCE || anontls_mode == ANONTLS_FORCE) { rfbLog("check_vnc_tls_mode: VENCRYPT_FORCE/ANONTLS_FORCE prevents normal SSL\n"); return 0; } return 1; } /* send RFB 003.008 -- there is no turning back from this point... */ if (!write_exact(s_out, proto, strlen(proto))) { close(s_in); close(s_out); return 0; } memset(buf, 0, sizeof(buf)); if (!read_exact(s_in, buf, 12)) { close(s_in); close(s_out); return 0; } if (sscanf(buf, "RFB %03d.%03d\n", &major, &minor) != 2) { int i; rfbLog("check_vnc_tls_mode: abnormal handshake: '%s'\nbytes: ", buf); for (i=0; i < 12; i++) { fprintf(stderr, "%x.", (int) buf[i]); } fprintf(stderr, "\n"); close(s_in); close(s_out); return 0; } rfbLog("check_vnc_tls_mode: version: %d.%d\n", major, minor); if (major != 3 || minor < 8) { rfbLog("check_vnc_tls_mode: invalid version: '%s'\n", buf); close(s_in); close(s_out); return 0; } n = 1; if (vencrypt_mode == VENCRYPT_FORCE) { buf[n++] = rfbSecTypeVencrypt; } else if (anontls_mode == ANONTLS_FORCE && !ssl_verify) { buf[n++] = rfbSecTypeAnonTls; } else if (vencrypt_mode == VENCRYPT_SOLE) { buf[n++] = rfbSecTypeVencrypt; } else if (anontls_mode == ANONTLS_SOLE && !ssl_verify) { buf[n++] = rfbSecTypeAnonTls; } else { if (vencrypt_mode == VENCRYPT_SUPPORT) { buf[n++] = rfbSecTypeVencrypt; } if (anontls_mode == ANONTLS_SUPPORT && !ssl_verify) { buf[n++] = rfbSecTypeAnonTls; } } n--; buf[0] = (char) n; if (!write_exact(s_out, buf, n+1)) { close(s_in); close(s_out); return 0; } if (0) fprintf(stderr, "wrote[%d] %d %d %d\n", n, buf[0], buf[1], buf[2]); buf[0] = 0; if (!read_exact(s_in, buf, 1)) { close(s_in); close(s_out); return 0; } if (buf[0] == rfbSecTypeVencrypt) stype = "VeNCrypt"; if (buf[0] == rfbSecTypeAnonTls) stype = "ANONTLS"; rfbLog("check_vnc_tls_mode: reply: %d (%s)\n", (int) buf[0], stype); ok = 0; for (i=1; i < n+1; i++) { if (buf[0] == buf[i]) { ok = 1; } } if (!ok) { char *msg = "check_vnc_tls_mode: invalid security-type"; int len = strlen(msg); rfbLog("%s: %d\n", msg, (int) buf[0]); ((uint32_t *)buf)[0] = Swap32IfLE(len); write_exact(s_out, buf, 4); write_exact(s_out, msg, strlen(msg)); close(s_in); close(s_out); return 0; } sectype = (int) buf[0]; if (sectype == rfbSecTypeVencrypt) { return vencrypt_dialog(s_in, s_out); } else if (sectype == rfbSecTypeAnonTls) { return anontls_dialog(s_in, s_out); } else { return 0; } } static void pr_ssl_info(int verb) { SSL_CIPHER *c; SSL_SESSION *s; char *proto = "unknown"; if (verb) {} if (ssl == NULL) { return; } c = SSL_get_current_cipher(ssl); s = SSL_get_session(ssl); if (s == NULL) { proto = "nosession"; } else if (s->ssl_version == SSL2_VERSION) { proto = "SSLv2"; } else if (s->ssl_version == SSL3_VERSION) { proto = "SSLv3"; } else if (s->ssl_version == TLS1_VERSION) { proto = "TLSv1"; } if (c != NULL) { rfbLog("SSL: ssl_helper[%d]: Cipher: %s %s Proto: %s\n", getpid(), SSL_CIPHER_get_version(c), SSL_CIPHER_get_name(c), proto); } else { rfbLog("SSL: ssl_helper[%d]: Proto: %s\n", getpid(), proto); } } static void ssl_timeout (int sig) { int i; rfbLog("sig: %d, ssl_init[%d] timed out.\n", sig, getpid()); for (i=0; i < 256; i++) { close(i); } exit(1); } static int ssl_init(int s_in, int s_out, int skip_vnc_tls) { unsigned char *sid = (unsigned char *) "x11vnc SID"; char *name = NULL; int peerport = 0; int db = 0, rc, err; int ssock = s_in; double start = dnow(); int timeout = 20; if (enc_str != NULL) { return 1; } if (getenv("SSL_DEBUG")) { db = atoi(getenv("SSL_DEBUG")); } if (getenv("SSL_INIT_TIMEOUT")) { timeout = atoi(getenv("SSL_INIT_TIMEOUT")); } if (db) fprintf(stderr, "ssl_init: %d/%d\n", s_in, s_out); if (skip_vnc_tls) { rfbLog("SSL: ssl_helper[%d]: HTTPS mode, skipping check_vnc_tls_mode()\n", getpid()); } else if (!check_vnc_tls_mode(s_in, s_out)) { return 0; } ssl = SSL_new(ctx); if (ssl == NULL) { fprintf(stderr, "SSL_new failed\n"); return 0; } if (db > 1) fprintf(stderr, "ssl_init: 1\n"); SSL_set_session_id_context(ssl, sid, strlen((char *)sid)); if (s_in == s_out) { if (! SSL_set_fd(ssl, ssock)) { fprintf(stderr, "SSL_set_fd failed\n"); return 0; } } else { if (! SSL_set_rfd(ssl, s_in)) { fprintf(stderr, "SSL_set_rfd failed\n"); return 0; } if (! SSL_set_wfd(ssl, s_out)) { fprintf(stderr, "SSL_set_wfd failed\n"); return 0; } } if (db > 1) fprintf(stderr, "ssl_init: 2\n"); if (ssl_client_mode) { SSL_set_connect_state(ssl); } else { SSL_set_accept_state(ssl); } if (db > 1) fprintf(stderr, "ssl_init: 3\n"); name = get_remote_host(ssock); peerport = get_remote_port(ssock); if (db > 1) fprintf(stderr, "ssl_init: 4\n"); while (1) { signal(SIGALRM, ssl_timeout); alarm(timeout); if (ssl_client_mode) { if (db) fprintf(stderr, "calling SSL_connect...\n"); rc = SSL_connect(ssl); } else { if (db) fprintf(stderr, "calling SSL_accept...\n"); rc = SSL_accept(ssl); } err = SSL_get_error(ssl, rc); alarm(0); signal(SIGALRM, SIG_DFL); if (ssl_client_mode) { if (db) fprintf(stderr, "SSL_connect %d/%d\n", rc, err); } else { 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: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n", getpid(), name, peerport); pr_ssl_info(1); return 0; } else if (err == SSL_ERROR_WANT_WRITE) { if (db) fprintf(stderr, "got SSL_ERROR_WANT_WRITE\n"); rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n", getpid(), name, peerport); pr_ssl_info(1); return 0; } else if (err == SSL_ERROR_SYSCALL) { if (db) fprintf(stderr, "got SSL_ERROR_SYSCALL\n"); rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n", getpid(), name, peerport); pr_ssl_info(1); return 0; } else if (err == SSL_ERROR_ZERO_RETURN) { if (db) fprintf(stderr, "got SSL_ERROR_ZERO_RETURN\n"); rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n", getpid(), name, peerport); pr_ssl_info(1); return 0; } else if (rc < 0) { unsigned long err; int cnt = 0; rfbLog("SSL: ssl_helper[%d]: SSL_accept() *FATAL: %d SSL FAILED\n", getpid(), rc); while ((err = ERR_get_error()) != 0) { rfbLog("SSL: %s\n", ERR_error_string(err, NULL)); if (cnt++ > 100) { break; } } pr_ssl_info(1); return 0; } else if (dnow() > start + 3.0) { rfbLog("SSL: ssl_helper[%d]: timeout looping SSL_accept() " "fatal.\n", getpid()); pr_ssl_info(1); return 0; } else { BIO *bio = SSL_get_rbio(ssl); if (bio == NULL) { rfbLog("SSL: ssl_helper[%d]: ssl BIO is null. " "fatal.\n", getpid()); pr_ssl_info(1); return 0; } if (BIO_eof(bio)) { rfbLog("SSL: ssl_helper[%d]: ssl BIO is EOF. " "fatal.\n", getpid()); pr_ssl_info(1); return 0; } } usleep(10 * 1000); } if (ssl_client_mode) { rfbLog("SSL: ssl_helper[%d]: SSL_connect() succeeded for: %s:%d\n", getpid(), name, peerport); } else { rfbLog("SSL: ssl_helper[%d]: SSL_accept() succeeded for: %s:%d\n", getpid(), name, peerport); } pr_ssl_info(0); if (SSL_get_verify_result(ssl) == X509_V_OK) { X509 *x; FILE *cr = NULL; if (certret != NULL) { cr = fopen(certret, "w"); } x = SSL_get_peer_certificate(ssl); if (x == NULL) { rfbLog("SSL: ssl_helper[%d]: accepted client %s x509 peer cert is null\n", getpid(), name); if (cr != NULL) { fprintf(cr, "NOCERT\n"); fclose(cr); } } else { rfbLog("SSL: ssl_helper[%d]: accepted client %s x509 cert is:\n", getpid(), name); #if LIBVNCSERVER_HAVE_X509_PRINT_EX_FP X509_print_ex_fp(stderr, x, 0, XN_FLAG_MULTILINE); #endif if (cr != NULL) { #if LIBVNCSERVER_HAVE_X509_PRINT_EX_FP X509_print_ex_fp(cr, x, 0, XN_FLAG_MULTILINE); #else rfbLog("** not compiled with libssl X509_print_ex_fp() function **\n"); if (users_list && strstr(users_list, "sslpeer=")) { rfbLog("** -users sslpeer= will not work! **\n"); } #endif fclose(cr); } } } free(name); return 1; } static void symmetric_encryption_xfer(int csock, int s_in, int s_out); static void ssl_xfer(int csock, int s_in, int s_out, int is_https) { int dbxfer = 0, db = 0, check_pending, fdmax, nfd, n, i, err; char cbuf[ABSIZE], sbuf[ABSIZE]; int cptr, sptr, c_rd, c_wr, s_rd, s_wr; fd_set rd, wr; struct timeval tv; int ssock, cnt = 0, ndata = 0; /* * we want to switch to a longer timeout for long term VNC * connections (in case the network is not working for periods of * time), but we also want the timeout shorter at the beginning * in case the client went away. */ time_t start; int tv_https_early = 60; int tv_https_later = 20; int tv_vnc_early = 40; int tv_vnc_later = 43200; /* was 300, stunnel: 43200 */ int tv_cutover = 70; int tv_closing = 60; int tv_use; if (dbxfer) { raw_xfer(csock, s_in, s_out); return; } if (enc_str != NULL) { if (!strcmp(enc_str, "none")) { usleep(250*1000); rfbLog("doing '-enc none' raw transfer (no encryption)\n"); raw_xfer(csock, s_in, s_out); } else { symmetric_encryption_xfer(csock, s_in, s_out); } return; } if (getenv("SSL_DEBUG")) { db = atoi(getenv("SSL_DEBUG")); } if (db) fprintf(stderr, "ssl_xfer begin\n"); start = time(NULL); if (is_https) { tv_use = tv_https_early; } else { tv_use = tv_vnc_early; } /* * csock: clear text socket with libvncserver. "C" * ssock: ssl data socket with remote vnc viewer. "S" * * to cover inetd mode, we have s_in and s_out, but in non-inetd * mode they both ssock. * * 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 */ for (i=0; i s_in) { ssock = s_out; } else { ssock = s_in; } 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 ABSIZE buffers */ sptr = 0; if (vencrypt_selected > 0 || anontls_selected > 0) { char tmp[16]; /* read and discard the extra RFB version */ memset(tmp, 0, sizeof(tmp)); read(csock, tmp, 12); if (0) fprintf(stderr, "extra: %s\n", tmp); } while (1) { int c_to_s, s_to_c, closing; 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; } cnt++; /* set up the fd sets for the two sockets for read & write: */ FD_ZERO(&rd); if (c_rd && cptr < ABSIZE) { /* 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 < ABSIZE || (cptr > 0 && SSL_want_read(ssl))) { FD_SET(s_in, &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 < ABSIZE && SSL_want_write(ssl))) { FD_SET(s_out, &wr); } } if (tv_cutover && time(NULL) > start + tv_cutover) { rfbLog("SSL: ssl_xfer[%d]: tv_cutover: %d\n", getpid(), tv_cutover); tv_cutover = 0; if (is_https) { tv_use = tv_https_later; } else { tv_use = tv_vnc_later; } /* try to clean out some zombies if we can. */ ssl_helper_pid(0, -2); } if (ssl_timeout_secs > 0) { tv_use = ssl_timeout_secs; } if ( (s_rd && c_rd) || cptr || sptr) { closing = 0; } else { closing = 1; tv_use = tv_closing; } tv.tv_sec = tv_use; tv.tv_usec = 0; /* do the select, repeat if interrupted */ do { if (ssl_timeout_secs == 0) { nfd = select(fdmax+1, &rd, &wr, NULL, NULL); } else { nfd = select(fdmax+1, &rd, &wr, NULL, &tv); } } while (nfd < 0 && errno == EINTR); if (db > 1) fprintf(stderr, "nfd: %d\n", nfd); if (nfd < 0) { rfbLog("SSL: ssl_xfer[%d]: select error: %d\n", getpid(), nfd); perror("select"); /* connection finished */ return; } if (nfd == 0) { if (!closing && tv_cutover && ndata > 25000) { static int cn = 0; /* probably ok, early windows iconify */ if (cn++ < 2) { rfbLog("SSL: ssl_xfer[%d]: early time" "out: %d\n", getpid(), ndata); } continue; } rfbLog("SSL: ssl_xfer[%d]: connection timedout. %d tv_use: %d\n", getpid(), ndata, tv_use); /* connection finished */ return; } /* used to see if SSL_pending() should be checked: */ check_pending = 0; /* AUDIT */ 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 == ABSIZE) { check_pending = 1; } sptr -= n; if (! s_rd && sptr == 0) { /* finished sending last of sbuf */ shutdown(csock, SHUT_WR); c_wr = 0; } ndata += n; } } if (s_wr) { if ((cptr > 0 && FD_ISSET(s_out, &wr)) || (SSL_want_read(ssl) && FD_ISSET(s_in, &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; } ndata += 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 && 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, ABSIZE - 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; ndata += n; } } if (s_rd) { if ((sptr < ABSIZE && FD_ISSET(s_in, &rd)) || (SSL_want_write(ssl) && FD_ISSET(s_out, &wr)) || (check_pending && SSL_pending(ssl))) { /* try to read some data from S into our sbuf */ n = SSL_read(ssl, sbuf + sptr, ABSIZE - sptr); err = SSL_get_error(ssl, n); if (err == SSL_ERROR_NONE) { /* good */ sptr += n; ndata += 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; static time_t last_waitall = 0; static double last_check = 0.0; double now; if (! use_openssl) { return; } if (time(NULL) > last_waitall + 120) { last_waitall = time(NULL); ssl_helper_pid(0, -2); /* waitall */ } if (openssl_sock < 0) { return; } now = dnow(); if (now < last_check + 0.5) { return; } last_check = now; 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; } rfbLog("SSL: accept_openssl(OPENSSL_VNC)\n"); accept_openssl(OPENSSL_VNC, -1); } void check_https(void) { fd_set fds; struct timeval tv; int nfds; static double last_check = 0.0; double now; if (! use_openssl || https_sock < 0) { return; } now = dnow(); if (now < last_check + 0.5) { return; } last_check = now; FD_ZERO(&fds); FD_SET(https_sock, &fds); tv.tv_sec = 0; tv.tv_usec = 0; nfds = select(https_sock+1, &fds, NULL, NULL, &tv); if (nfds <= 0) { return; } rfbLog("SSL: accept_openssl(OPENSSL_HTTPS)\n"); accept_openssl(OPENSSL_HTTPS, -1); } #define MSZ 4096 static void init_prng(void) { int db = 0, bytes, ubytes, fd; char file[MSZ], dtmp[100]; unsigned int sr; 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); ubytes = RAND_load_file("/dev/urandom", 64); bytes += ubytes; if (db) fprintf(stderr, "bytes read: %d / %d\n", bytes, ubytes); /* mix in more predictable stuff as well for fallback */ sprintf(dtmp, "/tmp/p%.8f.XXXXXX", dnow()); fd = mkstemp(dtmp); RAND_add(dtmp, strlen(dtmp), 0); if (fd >= 0) { close(fd); unlink(dtmp); } sprintf(dtmp, "%d-%.8f", (int) getpid(), dnow()); RAND_add(dtmp, strlen(dtmp), 0); if (!RAND_status()) { ubytes = -1; rfbLog("calling RAND_poll()\n"); RAND_poll(); } RAND_bytes((unsigned char *)&sr, 4); srand(sr); if (bytes > 0) { if (! quiet) { rfbLog("initialized PRNG with %d random bytes.\n", bytes); } if (ubytes > 32 && rnow() < 0.25) { RAND_write_file(file); } return; } bytes += RAND_load_file("/dev/random", 8); if (db) fprintf(stderr, "bytes read: %d\n", bytes); RAND_poll(); if (! quiet) { rfbLog("initialized PRNG with %d random bytes.\n", bytes); } } #endif /* FORK_OK */ #endif /* LIBVNCSERVER_HAVE_LIBSSL */ void raw_xfer(int csock, int s_in, int s_out) { char buf0[8192]; int sz = 8192, n, m, status, db = 1; char *buf; #ifdef FORK_OK pid_t par = getpid(); pid_t pid = fork(); buf = buf0; if (vnc_redirect) { /* change buf size some direction. */ } if (getenv("X11VNC_DEBUG_RAW_XFER")) { db = atoi(getenv("X11VNC_DEBUG_RAW_XFER")); } if (pid < 0) { exit(1); } /* this is for testing or special helper usage, no SSL just socket redir */ if (pid) { if (db) rfbLog("raw_xfer start: %d -> %d/%d\n", csock, s_in, s_out); while (1) { n = read(csock, buf, sz); if (n == 0 || (n < 0 && errno != EINTR) ) { break; } else if (n > 0) { int len = n; char *src = buf; if (db > 1) write(2, buf, n); while (len > 0) { m = write(s_out, src, len); if (m > 0) { src += m; len -= m; continue; } if (m < 0 && (errno == EINTR || errno == EAGAIN)) { continue; } if (db) rfbLog("raw_xfer bad write: %d -> %d | %d/%d errno=%d\n", csock, s_out, m, n, errno); break; } } } usleep(250*1000); kill(pid, SIGTERM); waitpid(pid, &status, WNOHANG); if (db) rfbLog("raw_xfer done: %d -> %d\n", csock, s_out); } else { if (db) usleep(50*1000); if (db) rfbLog("raw_xfer start: %d <- %d\n", csock, s_in); while (1) { n = read(s_in, buf, sz); if (n == 0 || (n < 0 && errno != EINTR) ) { break; } else if (n > 0) { int len = n; char *src = buf; if (db > 1) write(2, buf, n); while (len > 0) { m = write(csock, src, len); if (m > 0) { src += m; len -= m; continue; } if (m < 0 && (errno == EINTR || errno == EAGAIN)) { continue; } if (db) rfbLog("raw_xfer bad write: %d <- %d | %d/%d errno=%d\n", csock, s_in, m, n, errno); break; } } } usleep(250*1000); kill(par, SIGTERM); waitpid(par, &status, WNOHANG); if (db) rfbLog("raw_xfer done: %d <- %d\n", csock, s_in); } close(csock); close(s_in); close(s_out); #endif /* FORK_OK */ } #define ENC_MODULE #if LIBVNCSERVER_HAVE_LIBSSL #define ENC_HAVE_OPENSSL 1 #else #define ENC_HAVE_OPENSSL 0 #endif #include "enc.h" static void symmetric_encryption_xfer(int csock, int s_in, int s_out) { char tmp[100]; char *cipher, *keyfile, *q; if (! enc_str) { return; } cipher = (char *) malloc(strlen(enc_str) + 100); q = strchr(enc_str, ':'); if (!q) return; *q = '\0'; if (getenv("X11VNC_USE_ULTRADSM_IV")) { sprintf(cipher, "rev:%s", enc_str); } else { sprintf(cipher, "noultra:rev:%s", enc_str); } keyfile = strdup(q+1); *q = ':'; /* TBD: s_in != s_out */ if (s_out) {} sprintf(tmp, "fd=%d,%d", s_in, csock); enc_do(cipher, keyfile, "-1", tmp); }