=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/clientloop.c,v retrieving revision 1.131.2.2 retrieving revision 1.131.2.3 diff -u -r1.131.2.2 -r1.131.2.3 --- src/usr.bin/ssh/clientloop.c 2005/06/05 02:22:39 1.131.2.2 +++ src/usr.bin/ssh/clientloop.c 2005/09/02 03:45:00 1.131.2.3 @@ -59,7 +59,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: clientloop.c,v 1.131.2.2 2005/06/05 02:22:39 brad Exp $"); +RCSID("$OpenBSD: clientloop.c,v 1.131.2.3 2005/09/02 03:45:00 brad Exp $"); #include "ssh.h" #include "ssh1.h" @@ -140,6 +140,8 @@ struct confirm_ctx { int want_tty; int want_subsys; + int want_x_fwd; + int want_agent_fwd; Buffer cmd; char *term; struct termios tio; @@ -208,6 +210,109 @@ return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; } +#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" +void +client_x11_get_proto(const char *display, const char *xauth_path, + u_int trusted, char **_proto, char **_data) +{ + char cmd[1024]; + char line[512]; + char xdisplay[512]; + static char proto[512], data[512]; + FILE *f; + int got_data = 0, generated = 0, do_unlink = 0, i; + char *xauthdir, *xauthfile; + struct stat st; + + xauthdir = xauthfile = NULL; + *_proto = proto; + *_data = data; + proto[0] = data[0] = '\0'; + + if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { + debug("No xauth program."); + } else { + if (display == NULL) { + debug("x11_get_proto: DISPLAY not set"); + return; + } + /* + * Handle FamilyLocal case where $DISPLAY does + * not match an authorization entry. For this we + * just try "xauth list unix:displaynum.screennum". + * XXX: "localhost" match to determine FamilyLocal + * is not perfect. + */ + if (strncmp(display, "localhost:", 10) == 0) { + snprintf(xdisplay, sizeof(xdisplay), "unix:%s", + display + 10); + display = xdisplay; + } + if (trusted == 0) { + xauthdir = xmalloc(MAXPATHLEN); + xauthfile = xmalloc(MAXPATHLEN); + strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); + if (mkdtemp(xauthdir) != NULL) { + do_unlink = 1; + snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", + xauthdir); + snprintf(cmd, sizeof(cmd), + "%s -f %s generate %s " SSH_X11_PROTO + " untrusted timeout 1200 2>" _PATH_DEVNULL, + xauth_path, xauthfile, display); + debug2("x11_get_proto: %s", cmd); + if (system(cmd) == 0) + generated = 1; + } + } + snprintf(cmd, sizeof(cmd), + "%s %s%s list %s . 2>" _PATH_DEVNULL, + xauth_path, + generated ? "-f " : "" , + generated ? xauthfile : "", + display); + debug2("x11_get_proto: %s", cmd); + f = popen(cmd, "r"); + if (f && fgets(line, sizeof(line), f) && + sscanf(line, "%*s %511s %511s", proto, data) == 2) + got_data = 1; + if (f) + pclose(f); + } + + if (do_unlink) { + unlink(xauthfile); + rmdir(xauthdir); + } + if (xauthdir) + xfree(xauthdir); + if (xauthfile) + xfree(xauthfile); + + /* + * If we didn't get authentication data, just make up some + * data. The forwarding code will check the validity of the + * response anyway, and substitute this data. The X11 + * server, however, will ignore this fake data and use + * whatever authentication mechanisms it was using otherwise + * for the local connection. + */ + if (!got_data) { + u_int32_t rnd = 0; + + logit("Warning: No xauth data; " + "using fake authentication data for X11 forwarding."); + strlcpy(proto, SSH_X11_PROTO, sizeof proto); + for (i = 0; i < 16; i++) { + if (i % 4 == 0) + rnd = arc4random(); + snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", + rnd & 0xff); + rnd >>= 8; + } + } +} + /* * This is called when the interactive is entered. This checks if there is * an EOF coming on stdin. We must check this explicitly, as select() does @@ -528,6 +633,7 @@ client_extra_session2_setup(int id, void *arg) { struct confirm_ctx *cctx = arg; + const char *display; Channel *c; int i; @@ -536,6 +642,24 @@ if ((c = channel_lookup(id)) == NULL) fatal("%s: no channel for id %d", __func__, id); + display = getenv("DISPLAY"); + if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { + char *proto, *data; + /* Get reasonable local authentication information. */ + client_x11_get_proto(display, options.xauth_location, + options.forward_x11_trusted, &proto, &data); + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication spoofing."); + x11_request_forwarding_with_spoofing(id, display, proto, data); + /* XXX wait for reply */ + } + + if (cctx->want_agent_fwd && options.forward_agent) { + debug("Requesting authentication agent forwarding."); + channel_request_start(id, "auth-agent-req@openssh.com", 0); + packet_send(); + } + client_session2_setup(id, cctx->want_tty, cctx->want_subsys, cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env, client_subsystem_reply); @@ -556,12 +680,12 @@ { Buffer m; Channel *c; - int client_fd, new_fd[3], ver, i, allowed; + int client_fd, new_fd[3], ver, allowed; socklen_t addrlen; struct sockaddr_storage addr; struct confirm_ctx *cctx; char *cmd; - u_int len, env_len, command, flags; + u_int i, len, env_len, command, flags; uid_t euid; gid_t egid; @@ -601,7 +725,7 @@ buffer_free(&m); return; } - if ((ver = buffer_get_char(&m)) != 1) { + if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { error("%s: wrong client version %d", __func__, ver); buffer_free(&m); close(client_fd); @@ -616,13 +740,15 @@ switch (command) { case SSHMUX_COMMAND_OPEN: - if (options.control_master == 2) + if (options.control_master == SSHCTL_MASTER_ASK || + options.control_master == SSHCTL_MASTER_AUTO_ASK) allowed = ask_permission("Allow shared connection " "to %s? ", host); /* continue below */ break; case SSHMUX_COMMAND_TERMINATE: - if (options.control_master == 2) + if (options.control_master == SSHCTL_MASTER_ASK || + options.control_master == SSHCTL_MASTER_AUTO_ASK) allowed = ask_permission("Terminate shared connection " "to %s? ", host); if (allowed) @@ -633,7 +759,7 @@ buffer_clear(&m); buffer_put_int(&m, allowed); buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, /* version */1, &m) == -1) { + if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { error("%s: client msg_send failed", __func__); close(client_fd); buffer_free(&m); @@ -653,7 +779,7 @@ buffer_clear(&m); buffer_put_int(&m, allowed); buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, /* version */1, &m) == -1) { + if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { error("%s: client msg_send failed", __func__); close(client_fd); buffer_free(&m); @@ -674,7 +800,7 @@ buffer_free(&m); return; } - if ((ver = buffer_get_char(&m)) != 1) { + if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { error("%s: wrong client version %d", __func__, ver); buffer_free(&m); close(client_fd); @@ -685,6 +811,8 @@ memset(cctx, 0, sizeof(*cctx)); cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0; cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0; + cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0; + cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0; cctx->term = buffer_get_string(&m, &len); cmd = buffer_get_string(&m, &len); @@ -718,7 +846,7 @@ /* This roundtrip is just for synchronisation of ttymodes */ buffer_clear(&m); - if (ssh_msg_send(client_fd, /* version */1, &m) == -1) { + if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { error("%s: client msg_send failed", __func__); close(client_fd); close(new_fd[0]); @@ -866,7 +994,10 @@ u_char ch; char *s; - for (i = 0; i < len; i++) { + if (len <= 0) + return (0); + + for (i = 0; i < (u_int)len; i++) { /* Get one character at a time. */ ch = buf[i];