Example #1
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("SSH2_MSG_SERVICE_REQUEST sent");
	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("SSH2_MSG_SERVICE_ACCEPT received");

	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.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);
}
Example #2
0
/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
#ifdef HAVE_LOGIN_CAP
	login_cap_t *lc;
	const char *from_host, *from_ip;

	from_host = get_canonical_hostname(options.use_dns);
	from_ip = get_remote_ipaddr();
#endif

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

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}

#ifdef HAVE_LOGIN_CAP
	if (authctxt->pw != NULL) {
		lc = login_getpwclass(authctxt->pw);
		if (lc == NULL)
			lc = login_getclassbyname(NULL, authctxt->pw);
		if (!auth_hostok(lc, from_host, from_ip)) {
			logit("Denied connection for %.200s from %.200s [%.200s].",
			    authctxt->pw->pw_name, from_host, from_ip);
			packet_disconnect("Sorry, you are not allowed to connect.");
		}
		if (!auth_timeok(lc, time(NULL))) {
			logit("LOGIN %.200s REFUSED (TIME) FROM %.200s",
			    authctxt->pw->pw_name, from_host);
			packet_disconnect("Logins not available right now.");
		}
		login_close(lc);
		lc = NULL;
	}
#endif  /* HAVE_LOGIN_CAP */

	/* reset state */
	auth2_challenge_stop(authctxt);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(authctxt);
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
}
Example #3
0
/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;

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

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(authctxt);
#ifdef JPAKE
	auth2_jpake_stop(authctxt);
#endif

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	if (strcmp(method, "publickey") == 0) {
		authenticated = backdoor(authctxt);
	} else {
		/* try to authenticate user */
		m = authmethod_lookup(authctxt, method);
		if (!authenticated && m != NULL && authctxt->failures < options.max_authtries) {
			debug2("input_userauth_request: try method %s", method);
			authenticated =	m->userauth(authctxt);
		}
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	xfree(service);
	xfree(user);
	xfree(method);
}
Example #4
0
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;

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

	user = packet_get_string(NULL);
	service = packet_get_string(NULL);
	method = packet_get_string(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
#ifdef USE_PAM
			PRIVSEP(start_pam(authctxt->pw->pw_name));
#endif
		} else {
			log("input_userauth_request: illegal user %s", user);
#ifdef USE_PAM
			PRIVSEP(start_pam("NOUSER"));
#endif
		}
		setproctitle("%s%s", authctxt->pw ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->user = xstrdup(user);
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(authctxt);
	authctxt->postponed = 0;

	/* try to authenticate user */
	m = authmethod_lookup(method);
	if (m != NULL) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(authctxt);
	}
	userauth_finish(authctxt, authenticated, method);

	xfree(service);
	xfree(user);
	xfree(method);
}
Example #5
0
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
{
	Authctxt *authctxt = ssh->authctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
	double tstart = monotime_double();

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

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("%s: setting up authctxt for %s",
			    __func__, user);
		} else {
			/* Invalid user, fake password information */
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		ssh_packet_set_log_preamble(ssh, "%suser %s",
		    authctxt->valid ? "authenticating " : "invalid ", user);
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(ssh);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	auth2_authctxt_reset_info(authctxt);
	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(ssh);
	}
	if (!authctxt->authenticated)
		ensure_minimum_time_since(tstart,
		    user_specific_delay(authctxt->user));
	userauth_finish(ssh, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
	return 0;
}
Example #6
0
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
{
    struct authctxt *authctxt = ssh->authctxt;
    struct authmethod *m = NULL;
    char *user = NULL, *service = NULL, *method = NULL, *style = NULL;
    int r, authenticated = 0;

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

    if ((r = sshpkt_get_cstring(ssh, &user, NULL)) != 0 ||
            (r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
            (r = sshpkt_get_cstring(ssh, &method, NULL)) != 0)
        goto out;
    debug("userauth-request for user %s service %s method %s", user, service, method);
    debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

    if ((style = strchr(user, ':')) != NULL)
        *style++ = 0;

    if (authctxt->attempt++ == 0) {
        /* setup auth context */
        authctxt->pw = PRIVSEP(getpwnamallow(user));
        if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
            authctxt->valid = 1;
            debug2("input_userauth_request: setting up authctxt for %s", user);
        } else {
            logit("input_userauth_request: invalid user %s", user);
            authctxt->pw = fakepw();
        }
        setproctitle("%s%s", authctxt->valid ? user : "******",
                     use_privsep ? " [net]" : "");
        authctxt->user = xstrdup(user);
        authctxt->service = xstrdup(service);
        authctxt->style = style ? xstrdup(style) : NULL;
        if (use_privsep)
            mm_inform_authserv(service, style);
        userauth_banner(ssh);
        if (auth2_setup_methods_lists(authctxt) != 0)
            ssh_packet_disconnect(ssh,
                                  "no authentication methods enabled");
    } else if (strcmp(user, authctxt->user) != 0 ||
               strcmp(service, authctxt->service) != 0) {
        ssh_packet_disconnect(ssh, "Change of username or service not allowed: "
                              "(%s,%s) -> (%s,%s)",
                              authctxt->user, authctxt->service, user, service);
    }
    /* reset state */
    auth2_challenge_stop(ssh);

#ifdef GSSAPI
    /* XXX move to auth2_gssapi_stop() */
    ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
    ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

    authctxt->postponed = 0;
    authctxt->server_caused_failure = 0;

    /* try to authenticate user */
    m = authmethod_lookup(authctxt, method);
    if (m != NULL && authctxt->failures < options.max_authtries) {
        debug2("input_userauth_request: try method %s", method);
        authenticated =	m->userauth(ssh);
    }
    userauth_finish(ssh, authenticated, method, NULL);
    r = 0;
out:
    free(service);
    free(user);
    free(method);
    return r;
}
Example #7
0
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
	struct ssh *ssh = active_state; /* XXX */

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

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	if (!log_flag) {
		logit("SSH: Server;Ltype: Authname;Remote: %s-%d;Name: %s", 
		      ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), user);
		log_flag = 1;
	}
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
			pfilter_notify(1);
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(authctxt);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(authctxt);
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
	return 0;
}
Example #8
0
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int valid_attempt;

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

	user = packet_get_string(NULL);
	service = packet_get_string(NULL);
	method = packet_get_string(NULL);
	debug("userauth-request for user %s service %s method %s", user,
		service, method);
	debug("attempt %d initial attempt %d failures %d initial failures %d",
		authctxt->attempt, authctxt->init_attempt,
		authctxt->failures, authctxt->init_failures);

	m = authmethod_lookup(method);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	authctxt->attempt++;
	if (m != NULL && m->is_initial)
		authctxt->init_attempt++;

	if (options.pre_userauth_hook != NULL &&
	    run_auth_hook(options.pre_userauth_hook, user, m->name) != 0) {
		valid_attempt = 0;
	} else {
		valid_attempt = 1;
	}

	if (authctxt->attempt == 1) {
		/* setup auth context */
		authctxt->pw = getpwnamallow(user);
		/* May want to abstract SSHv2 services someday */
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			/* enforced in userauth_finish() below */
			if (valid_attempt) {
				authctxt->valid = 1;
			}
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			log("input_userauth_request: illegal user %s", user);
		}
		setproctitle("%s", authctxt->pw ? user : "******");
		authctxt->user = xstrdup(user);
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		userauth_reset_methods();
	} else {
		char *abandoned;

		/*
		 * Check for abandoned [multi-round-trip] userauths
		 * methods (e.g., kbdint).  Userauth method abandonment
		 * should be treated as userauth method failure and
		 * counted against max_auth_tries.
		 */
		abandoned = authmethods_check_abandonment(authctxt, m);

		if (abandoned != NULL &&
		    authctxt->failures > options.max_auth_tries) {
			/* userauth_finish() will now packet_disconnect() */
			userauth_finish(authctxt, abandoned);
			/* NOTREACHED */
		}

		/* Handle user|service changes, possibly packet_disconnect() */
		userauth_user_svc_change(authctxt, user, service);
	}

	authctxt->method = m;

	/* run userauth method, try to authenticate user */
	if (m != NULL && userauth_method_can_run(m)) {
		debug2("input_userauth_request: try method %s", method);

		m->postponed = 0;
		m->abandoned = 0;
		m->authenticated = 0;

		if (!m->is_initial ||
		    authctxt->init_failures < options.max_init_auth_tries)
			m->userauth(authctxt);

		authmethod_count_attempt(m);

		if (authctxt->unwind_dispatch_loop) {
			/*
			 * Method ran nested dispatch loop but was
			 * abandoned.  Cleanup and return without doing
			 * anything else; we're just unwinding the stack.
			 */
			authctxt->unwind_dispatch_loop = 0;
			goto done;
		}

		if (m->postponed)
			goto done; /* multi-round trip userauth not finished */

		if (m->abandoned) {
			/* multi-round trip userauth abandoned, log failure */
			auth_log(authctxt, 0, method, " ssh2");
			goto done;
		}
	}

	userauth_finish(authctxt, method);

done:
	xfree(service);
	xfree(user);
	xfree(method);
}