Exemplo n.º 1
0
/*
  handler for completion of a smbcli_request sub-request
*/
static void request_handler(struct smbcli_request *req)
{
	struct composite_context *c = (struct composite_context *)req->async.private_data;
	struct sesssetup_state *state = talloc_get_type(c->private_data, struct sesssetup_state);
	struct smbcli_session *session = req->session;
	DATA_BLOB null_data_blob = data_blob(NULL, 0);
	NTSTATUS session_key_err, nt_status;
	struct smbcli_request *check_req = NULL;
	const char *os = NULL;
	const char *lanman = NULL;

	if (req->sign_caller_checks) {
		req->do_not_free = true;
		check_req = req;
	}

	state->remote_status = smb_raw_sesssetup_recv(req, state, &state->setup);
	c->status = state->remote_status;
	state->req = NULL;

	/*
	 * we only need to check the signature if the
	 * NT_STATUS_OK is returned
	 */
	if (!NT_STATUS_IS_OK(state->remote_status)) {
		talloc_free(check_req);
		check_req = NULL;
	}

	switch (state->setup.old.level) {
	case RAW_SESSSETUP_OLD:
		state->io->out.vuid = state->setup.old.out.vuid;
		/* This doesn't work, as this only happens on old
		 * protocols, where this comparison won't match. */
		if (NT_STATUS_EQUAL(c->status, NT_STATUS_LOGON_FAILURE)) {
			/* we neet to reset the vuid for a new try */
			session->vuid = 0;
			if (cli_credentials_wrong_password(state->io->in.credentials)) {
				nt_status = session_setup_old(c, session, 
							      state->io, 
							      &state->req);
				if (NT_STATUS_IS_OK(nt_status)) {
					talloc_free(check_req);
					c->status = nt_status;
					composite_continue_smb(c, state->req, request_handler, c);
					return;
				}
			}
		}
		os = state->setup.old.out.os;
		lanman = state->setup.old.out.lanman;
		break;

	case RAW_SESSSETUP_NT1:
		state->io->out.vuid = state->setup.nt1.out.vuid;
		if (NT_STATUS_EQUAL(c->status, NT_STATUS_LOGON_FAILURE)) {
			/* we need to reset the vuid for a new try */
			session->vuid = 0;
			if (cli_credentials_wrong_password(state->io->in.credentials)) {
				nt_status = session_setup_nt1(c, session, 
							      state->io, 
							      &state->req);
				if (NT_STATUS_IS_OK(nt_status)) {
					talloc_free(check_req);
					c->status = nt_status;
					composite_continue_smb(c, state->req, request_handler, c);
					return;
				}
			}
		}
		os = state->setup.nt1.out.os;
		lanman = state->setup.nt1.out.lanman;
		break;

	case RAW_SESSSETUP_SPNEGO:
		state->io->out.vuid = state->setup.spnego.out.vuid;
		if (NT_STATUS_EQUAL(c->status, NT_STATUS_LOGON_FAILURE)) {
			const char *principal;

			/* we need to reset the vuid for a new try */
			session->vuid = 0;

			principal = gensec_get_target_principal(session->gensec);
			if (principal == NULL) {
				const char *hostname = gensec_get_target_hostname(session->gensec);
				const char *service  = gensec_get_target_service(session->gensec);
				if (hostname != NULL && service != NULL) {
					principal = talloc_asprintf(state, "%s/%s", service, hostname);
				}
			}
			if (cli_credentials_failed_kerberos_login(state->io->in.credentials, principal, &state->logon_retries) ||
			    cli_credentials_wrong_password(state->io->in.credentials)) {
				nt_status = session_setup_spnego(c, session, 
								      state->io, 
								      &state->req);
				if (NT_STATUS_IS_OK(nt_status)) {
					talloc_free(check_req);
					c->status = nt_status;
					composite_continue_smb(c, state->req, request_handler, c);
					return;
				}
			}
		}
		if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
		    !NT_STATUS_IS_OK(c->status)) {
			break;
		}
		if (NT_STATUS_EQUAL(state->gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {

			/* The status value here, from the earlier pass at GENSEC is
			 * vital to the security of the system.  Even if the other end
			 * accepts, if GENSEC claims 'MORE_PROCESSING_REQUIRED' then
			 * you must keep feeding it blobs, or else the remote
			 * host/attacker might avoid mutal authentication
			 * requirements */
			
			state->gensec_status = gensec_update(session->gensec, state, c->event_ctx,
							 state->setup.spnego.out.secblob,
							 &state->setup.spnego.in.secblob);
			c->status = state->gensec_status;
			if (!NT_STATUS_EQUAL(c->status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
			    !NT_STATUS_IS_OK(c->status)) {
				break;
			}
		} else {
			state->setup.spnego.in.secblob = data_blob(NULL, 0);
		}

		if (NT_STATUS_IS_OK(state->remote_status)) {
			DATA_BLOB session_key;

			if (state->setup.spnego.in.secblob.length) {
				c->status = NT_STATUS_INTERNAL_ERROR;
				break;
			}
			session_key_err = gensec_session_key(session->gensec, session, &session_key);
			if (NT_STATUS_IS_OK(session_key_err)) {
				smb1cli_conn_activate_signing(session->transport->conn,
							      session_key,
							      null_data_blob);
			}

			c->status = smb1cli_session_set_session_key(session->smbXcli,
								    session_key);
			data_blob_free(&session_key);
			if (!NT_STATUS_IS_OK(c->status)) {
				break;
			}
		}

		if (state->setup.spnego.in.secblob.length) {
			/* 
			 * set the session->vuid value only for calling
			 * smb_raw_sesssetup_send()
			 */
			uint16_t vuid = session->vuid;
			session->vuid = state->io->out.vuid;
			state->req = smb_raw_sesssetup_send(session, &state->setup);
			session->vuid = vuid;
			if (state->req &&
			    !smb1cli_conn_signing_is_active(state->req->transport->conn)) {
				state->req->sign_caller_checks = true;
			}
			composite_continue_smb(c, state->req, request_handler, c);
			return;
		}
		os = state->setup.spnego.out.os;
		lanman = state->setup.spnego.out.lanman;
		break;

	case RAW_SESSSETUP_SMB2:
		c->status = NT_STATUS_INTERNAL_ERROR;
		break;
	}

	if (check_req) {
		bool ok;

		check_req->sign_caller_checks = false;

		ok = smb1cli_conn_check_signing(check_req->transport->conn,
						check_req->in.buffer, 1);
		if (!ok) {
			c->status = NT_STATUS_ACCESS_DENIED;
		}
		talloc_free(check_req);
		check_req = NULL;
	}

	if (!NT_STATUS_IS_OK(c->status)) {
		composite_error(c, c->status);
		return;
	}

	if (os) {
		session->os = talloc_strdup(session, os);
		if (composite_nomem(session->os, c)) return;
	} else {
		session->os = NULL;
	}
	if (lanman) {
		session->lanman = talloc_strdup(session, lanman);
		if (composite_nomem(session->lanman, c)) return;
	} else {
		session->lanman = NULL;
	}

	composite_done(c);
}
Exemplo n.º 2
0
/*
  perform a sasl bind using the given credentials
*/
_PUBLIC_ NTSTATUS ldap_bind_sasl(struct ldap_connection *conn,
			struct cli_credentials *creds,
			struct loadparm_context *lp_ctx)
{
	NTSTATUS status;
	TALLOC_CTX *tmp_ctx = NULL;

	DATA_BLOB input = data_blob(NULL, 0);
	DATA_BLOB output = data_blob(NULL, 0);

	struct ldap_message **sasl_mechs_msgs;
	struct ldap_SearchResEntry *search;
	int count, i;

	const char **sasl_names;
	uint32_t old_gensec_features;
	static const char *supported_sasl_mech_attrs[] = {
		"supportedSASLMechanisms", 
		NULL 
	};
	unsigned int logon_retries = 0;

	status = ildap_search(conn, "", LDAP_SEARCH_SCOPE_BASE, "", supported_sasl_mech_attrs,
			      false, NULL, NULL, &sasl_mechs_msgs);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: %s\n",
			  nt_errstr(status)));
		goto failed;
	}

	count = ildap_count_entries(conn, sasl_mechs_msgs);
	if (count != 1) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of replies: %d\n",
			  count));
		goto failed;
	}

	tmp_ctx = talloc_new(conn);
	if (tmp_ctx == NULL) goto failed;

	search = &sasl_mechs_msgs[0]->r.SearchResultEntry;
	if (search->num_attributes != 1) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of attributes: %d != 1\n",
			  search->num_attributes));
		goto failed;
	}

	sasl_names = talloc_array(tmp_ctx, const char *, search->attributes[0].num_values + 1);
	if (!sasl_names) {
		DEBUG(1, ("talloc_arry(char *, %d) failed\n",
			  count));
		goto failed;
	}

	for (i=0; i<search->attributes[0].num_values; i++) {
		sasl_names[i] = (const char *)search->attributes[0].values[i].data;
	}
	sasl_names[i] = NULL;

	gensec_init();

try_logon_again:
	/*
	  we loop back here on a logon failure, and re-create the
	  gensec session. The logon_retries counter ensures we don't
	  loop forever.
	 */

	status = gensec_client_start(conn, &conn->gensec,
				     lpcfg_gensec_settings(conn, lp_ctx));
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
		goto failed;
	}

	/* require Kerberos SIGN/SEAL only if we don't use SSL
	 * Windows seem not to like double encryption */
	old_gensec_features = cli_credentials_get_gensec_features(creds);
	if (tls_enabled(conn->sock)) {
		cli_credentials_set_gensec_features(creds, old_gensec_features & ~(GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL));
	}

	/* this call also sets the gensec_want_features */
	status = gensec_set_credentials(conn->gensec, creds);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to set GENSEC creds: %s\n", 
			  nt_errstr(status)));
		goto failed;
	}

	/* reset the original gensec_features (on the credentials
	 * context, so we don't tatoo it ) */
	cli_credentials_set_gensec_features(creds, old_gensec_features);

	if (conn->host) {
		status = gensec_set_target_hostname(conn->gensec, conn->host);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(1, ("Failed to set GENSEC target hostname: %s\n", 
				  nt_errstr(status)));
			goto failed;
		}
	}

	status = gensec_set_target_service(conn->gensec, "ldap");
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to set GENSEC target service: %s\n", 
			  nt_errstr(status)));
		goto failed;
	}

	status = gensec_start_mech_by_sasl_list(conn->gensec, sasl_names);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("None of the %d proposed SASL mechs were acceptable: %s\n",
			  count, nt_errstr(status)));
		goto failed;
	}

	while (1) {
		NTSTATUS gensec_status;
		struct ldap_message *response;
		struct ldap_message *msg;
		struct ldap_request *req;
		int result = LDAP_OTHER;
	
		status = gensec_update(conn->gensec, tmp_ctx,
				       conn->event.event_ctx,
				       input,
				       &output);
		/* The status value here, from GENSEC is vital to the security
		 * of the system.  Even if the other end accepts, if GENSEC
		 * claims 'MORE_PROCESSING_REQUIRED' then you must keep
		 * feeding it blobs, or else the remote host/attacker might
		 * avoid mutal authentication requirements.
		 *
		 * Likewise, you must not feed GENSEC too much (after the OK),
		 * it doesn't like that either
		 */

		gensec_status = status;

		if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
		    !NT_STATUS_IS_OK(status)) {
			break;
		}
		if (NT_STATUS_IS_OK(status) && output.length == 0) {
			break;
		}

		/* Perhaps we should make gensec_start_mech_by_sasl_list() return the name we got? */
		msg = new_ldap_sasl_bind_msg(tmp_ctx, conn->gensec->ops->sasl_name, (output.data?&output:NULL));
		if (msg == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}

		req = ldap_request_send(conn, msg);
		if (req == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}
		talloc_reparent(conn, tmp_ctx, req);

		status = ldap_result_n(req, 0, &response);
		if (!NT_STATUS_IS_OK(status)) {
			goto failed;
		}
		
		if (response->type != LDAP_TAG_BindResponse) {
			status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
			goto failed;
		}

		result = response->r.BindResponse.response.resultcode;

		if (result == LDAP_INVALID_CREDENTIALS) {
			/*
			  try a second time on invalid credentials, to
			  give the user a chance to re-enter the
			  password and to handle the case where our
			  kerberos ticket is invalid as the server
			  password has changed
			*/
			const char *principal;

			principal = gensec_get_target_principal(conn->gensec);
			if (principal == NULL) {
				const char *hostname = gensec_get_target_hostname(conn->gensec);
				const char *service  = gensec_get_target_service(conn->gensec);
				if (hostname != NULL && service != NULL) {
					principal = talloc_asprintf(tmp_ctx, "%s/%s", service, hostname);
				}
			}

			if (cli_credentials_failed_kerberos_login(creds, principal, &logon_retries) ||
			    cli_credentials_wrong_password(creds)) {
				/*
				  destroy our gensec session and loop
				  back up to the top to retry,
				  offering the user a chance to enter
				  new credentials, or get a new ticket
				  if using kerberos
				 */
				talloc_free(conn->gensec);
				conn->gensec = NULL;
				goto try_logon_again;
			}
		}

		if (result != LDAP_SUCCESS && result != LDAP_SASL_BIND_IN_PROGRESS) {
			status = ldap_check_response(conn, 
						     &response->r.BindResponse.response);
			break;
		}

		/* This is where we check if GENSEC wanted to be fed more data */
		if (!NT_STATUS_EQUAL(gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
			break;
		}
		if (response->r.BindResponse.SASL.secblob) {
			input = *response->r.BindResponse.SASL.secblob;
		} else {
			input = data_blob(NULL, 0);
		}
	}

	talloc_free(tmp_ctx);

	if (NT_STATUS_IS_OK(status)) {
		struct socket_context *sasl_socket;
		status = gensec_socket_init(conn->gensec, 
					    conn,
					    conn->sock,
					    conn->event.event_ctx, 
					    ldap_read_io_handler,
					    conn,
					    &sasl_socket);
		if (!NT_STATUS_IS_OK(status)) goto failed;

		conn->sock = sasl_socket;
		packet_set_socket(conn->packet, conn->sock);

		conn->bind.type = LDAP_BIND_SASL;
		conn->bind.creds = creds;
	}

	return status;

failed:
	talloc_free(tmp_ctx);
	talloc_free(conn->gensec);
	conn->gensec = NULL;
	return status;
}
Exemplo n.º 3
0
static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
{
	struct gensec_gssapi_state *gensec_gssapi_state;
	struct cli_credentials *creds = gensec_get_credentials(gensec_security);
	NTSTATUS nt_status;
	gss_buffer_desc name_token;
	gss_OID name_type;
	OM_uint32 maj_stat, min_stat;
	const char *hostname = gensec_get_target_hostname(gensec_security);

	if (!hostname) {
		DEBUG(3, ("No hostname for target computer passed in, cannot use kerberos for this connection\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (is_ipaddress(hostname)) {
		DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (strcmp(hostname, "localhost") == 0) {
		DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	nt_status = gensec_gssapi_start(gensec_security);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);

	if (cli_credentials_get_impersonate_principal(creds)) {
		gensec_gssapi_state->gss_want_flags &= ~(GSS_C_DELEG_FLAG|GSS_C_DELEG_POLICY_FLAG);
	}

	gensec_gssapi_state->target_principal = gensec_get_target_principal(gensec_security);
	if (gensec_gssapi_state->target_principal) {
		name_type = GSS_C_NULL_OID;
	} else {
		gensec_gssapi_state->target_principal = talloc_asprintf(gensec_gssapi_state, "%s/%s@%s",
					    gensec_get_target_service(gensec_security), 
					    hostname, cli_credentials_get_realm(creds));

		name_type = GSS_C_NT_USER_NAME;
	}
	name_token.value  = discard_const_p(uint8_t, gensec_gssapi_state->target_principal);
	name_token.length = strlen(gensec_gssapi_state->target_principal);


	maj_stat = gss_import_name (&min_stat,
				    &name_token,
				    name_type,
				    &gensec_gssapi_state->server_name);
	if (maj_stat) {
		DEBUG(2, ("GSS Import name of %s failed: %s\n",
			  (char *)name_token.value,
			  gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
		return NT_STATUS_INVALID_PARAMETER;
	}

	return NT_STATUS_OK;
}
Exemplo n.º 4
0
static NTSTATUS gensec_krb5_common_client_creds(struct gensec_security *gensec_security,
						struct tevent_context *ev,
						bool gssapi)
{
	struct gensec_krb5_state *gensec_krb5_state;
	krb5_error_code ret;
	struct ccache_container *ccache_container;
	const char *error_string;
	const char *principal;
	const char *hostname;
	krb5_data in_data;
	struct tevent_context *previous_ev;

	gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;

	principal = gensec_get_target_principal(gensec_security);
	hostname = gensec_get_target_hostname(gensec_security);

	ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), 
				         ev,
					 gensec_security->settings->lp_ctx, &ccache_container, &error_string);
	switch (ret) {
	case 0:
		break;
	case KRB5KDC_ERR_PREAUTH_FAILED:
	case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
		return NT_STATUS_LOGON_FAILURE;
	case KRB5_KDC_UNREACH:
		DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	case KRB5_CC_NOTFOUND:
	case KRB5_CC_END:
		DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	default:
		DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
		return NT_STATUS_UNSUCCESSFUL;
	}
	in_data.length = 0;
	
	/* Do this every time, in case we have weird recursive issues here */
	ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, ev, &previous_ev);
	if (ret != 0) {
		DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
		return NT_STATUS_NO_MEMORY;
	}
	if (principal) {
		krb5_principal target_principal;
		ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
				      &target_principal);
		if (ret == 0) {
			ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context, 
						&gensec_krb5_state->auth_context,
						gensec_krb5_state->ap_req_options, 
						target_principal,
						&in_data, ccache_container->ccache, 
						&gensec_krb5_state->enc_ticket);
			krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context, 
					    target_principal);
		}
	} else {
		ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context, 
				  &gensec_krb5_state->auth_context,
				  gensec_krb5_state->ap_req_options,
				  gensec_get_target_service(gensec_security),
				  hostname,
				  &in_data, ccache_container->ccache, 
				  &gensec_krb5_state->enc_ticket);
	}

	smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, ev);

	switch (ret) {
	case 0:
		return NT_STATUS_OK;
	case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
		DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n", 
			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	case KRB5_KDC_UNREACH:
		DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	case KRB5KDC_ERR_PREAUTH_FAILED:
	case KRB5KRB_AP_ERR_TKT_EXPIRED:
	case KRB5_CC_END:
		/* Too much clock skew - we will need to kinit to re-skew the clock */
	case KRB5KRB_AP_ERR_SKEW:
	case KRB5_KDCREP_SKEW:
	{
		DEBUG(3, ("kerberos (mk_req) failed: %s\n", 
			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		/*fall through*/
	}
	
	/* just don't print a message for these really ordinary messages */
	case KRB5_FCC_NOFILE:
	case KRB5_CC_NOTFOUND:
	case ENOENT:
		
		return NT_STATUS_UNSUCCESSFUL;
		break;
		
	default:
		DEBUG(0, ("kerberos: %s\n", 
			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_UNSUCCESSFUL;
	}
}
Exemplo n.º 5
0
static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
{
	struct gensec_krb5_state *gensec_krb5_state;
	krb5_error_code ret;
	NTSTATUS nt_status;
	struct ccache_container *ccache_container;
	const char *hostname;

	const char *principal;
	krb5_data in_data;

	hostname = gensec_get_target_hostname(gensec_security);
	if (!hostname) {
		DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (is_ipaddress(hostname)) {
		DEBUG(2, ("Cannot do krb5 to an IP address"));
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (strcmp(hostname, "localhost") == 0) {
		DEBUG(2, ("krb5 to 'localhost' does not make sense"));
		return NT_STATUS_INVALID_PARAMETER;
	}
			
	nt_status = gensec_krb5_start(gensec_security, gssapi);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
	gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
	gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;

	if (gensec_krb5_state->gssapi) {
		/* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
		if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
			gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
		}
	} else {
		/* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
		if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
			gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
		}
	}

	principal = gensec_get_target_principal(gensec_security);

	ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), 
				         gensec_security->event_ctx, 
					 gensec_security->settings->lp_ctx, &ccache_container);
	switch (ret) {
	case 0:
		break;
	case KRB5KDC_ERR_PREAUTH_FAILED:
		return NT_STATUS_LOGON_FAILURE;
	case KRB5_KDC_UNREACH:
		DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	default:
		DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_message(ret)));
		return NT_STATUS_UNSUCCESSFUL;
	}
	in_data.length = 0;
	
	if (principal && lp_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
		krb5_principal target_principal;
		ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
				      &target_principal);
		if (ret == 0) {
			ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context, 
						&gensec_krb5_state->auth_context,
						gensec_krb5_state->ap_req_options, 
						target_principal,
						&in_data, ccache_container->ccache, 
						&gensec_krb5_state->enc_ticket);
			krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context, 
					    target_principal);
		}
	} else {
		ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context, 
				  &gensec_krb5_state->auth_context,
				  gensec_krb5_state->ap_req_options,
				  gensec_get_target_service(gensec_security),
				  hostname,
				  &in_data, ccache_container->ccache, 
				  &gensec_krb5_state->enc_ticket);
	}
	switch (ret) {
	case 0:
		return NT_STATUS_OK;
	case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
		DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n", 
			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	case KRB5_KDC_UNREACH:
		DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
	case KRB5KDC_ERR_PREAUTH_FAILED:
	case KRB5KRB_AP_ERR_TKT_EXPIRED:
	case KRB5_CC_END:
		/* Too much clock skew - we will need to kinit to re-skew the clock */
	case KRB5KRB_AP_ERR_SKEW:
	case KRB5_KDCREP_SKEW:
	{
		DEBUG(3, ("kerberos (mk_req) failed: %s\n", 
			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		/*fall through*/
	}
	
	/* just don't print a message for these really ordinary messages */
	case KRB5_FCC_NOFILE:
	case KRB5_CC_NOTFOUND:
	case ENOENT:
		
		return NT_STATUS_UNSUCCESSFUL;
		break;
		
	default:
		DEBUG(0, ("kerberos: %s\n", 
			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
		return NT_STATUS_UNSUCCESSFUL;
	}
}
Exemplo n.º 6
0
/*
  perform a sasl bind using the given credentials
*/
_PUBLIC_ NTSTATUS ldap_bind_sasl(struct ldap_connection *conn,
			struct cli_credentials *creds,
			struct loadparm_context *lp_ctx)
{
	NTSTATUS status;
	TALLOC_CTX *tmp_ctx = NULL;

	DATA_BLOB input = data_blob(NULL, 0);
	DATA_BLOB output = data_blob(NULL, 0);

	struct ldap_message **sasl_mechs_msgs;
	struct ldap_SearchResEntry *search;
	int count, i;
	bool first = true;
	int wrap_flags = 0;
	const char **sasl_names;
	uint32_t old_gensec_features;
	static const char *supported_sasl_mech_attrs[] = {
		"supportedSASLMechanisms", 
		NULL 
	};
	unsigned int logon_retries = 0;
	size_t queue_length;

	if (conn->sockets.active == NULL) {
		status = NT_STATUS_CONNECTION_DISCONNECTED;
		goto failed;
	}

	queue_length = tevent_queue_length(conn->sockets.send_queue);
	if (queue_length != 0) {
		status = NT_STATUS_INVALID_PARAMETER_MIX;
		DEBUG(1, ("SASL bind triggered with non empty send_queue[%zu]: %s\n",
			  queue_length, nt_errstr(status)));
		goto failed;
	}

	if (conn->pending != NULL) {
		status = NT_STATUS_INVALID_PARAMETER_MIX;
		DEBUG(1, ("SASL bind triggered with pending requests: %s\n",
			  nt_errstr(status)));
		goto failed;
	}

	status = ildap_search(conn, "", LDAP_SEARCH_SCOPE_BASE, "", supported_sasl_mech_attrs,
			      false, NULL, NULL, &sasl_mechs_msgs);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: %s\n",
			  nt_errstr(status)));
		goto failed;
	}

	count = ildap_count_entries(conn, sasl_mechs_msgs);
	if (count != 1) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of replies: %d\n",
			  count));
		goto failed;
	}

	tmp_ctx = talloc_new(conn);
	if (tmp_ctx == NULL) goto failed;

	search = &sasl_mechs_msgs[0]->r.SearchResultEntry;
	if (search->num_attributes != 1) {
		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of attributes: %d != 1\n",
			  search->num_attributes));
		goto failed;
	}

	sasl_names = talloc_array(tmp_ctx, const char *, search->attributes[0].num_values + 1);
	if (!sasl_names) {
		DEBUG(1, ("talloc_arry(char *, %d) failed\n",
			  count));
		goto failed;
	}

	for (i=0; i<search->attributes[0].num_values; i++) {
		sasl_names[i] = (const char *)search->attributes[0].values[i].data;
	}
	sasl_names[i] = NULL;

	gensec_init();

	if (conn->sockets.active == conn->sockets.tls) {
		/*
		 * require Kerberos SIGN/SEAL only if we don't use SSL
		 * Windows seem not to like double encryption
		 */
		wrap_flags = 0;
	} else if (cli_credentials_is_anonymous(creds)) {
		/*
		 * anonymous isn't protected
		 */
		wrap_flags = 0;
	} else {
		wrap_flags = lpcfg_client_ldap_sasl_wrapping(lp_ctx);
	}

try_logon_again:
	/*
	  we loop back here on a logon failure, and re-create the
	  gensec session. The logon_retries counter ensures we don't
	  loop forever.
	 */
	data_blob_free(&input);
	TALLOC_FREE(conn->gensec);

	status = gensec_client_start(conn, &conn->gensec,
				     lpcfg_gensec_settings(conn, lp_ctx));
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
		goto failed;
	}

	old_gensec_features = cli_credentials_get_gensec_features(creds);
	if (wrap_flags == 0) {
		cli_credentials_set_gensec_features(creds, old_gensec_features & ~(GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL));
	}

	/* this call also sets the gensec_want_features */
	status = gensec_set_credentials(conn->gensec, creds);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to set GENSEC creds: %s\n", 
			  nt_errstr(status)));
		goto failed;
	}

	/* reset the original gensec_features (on the credentials
	 * context, so we don't tatoo it ) */
	cli_credentials_set_gensec_features(creds, old_gensec_features);

	if (wrap_flags & ADS_AUTH_SASL_SEAL) {
		gensec_want_feature(conn->gensec, GENSEC_FEATURE_SIGN);
		gensec_want_feature(conn->gensec, GENSEC_FEATURE_SEAL);
	}
	if (wrap_flags & ADS_AUTH_SASL_SIGN) {
		gensec_want_feature(conn->gensec, GENSEC_FEATURE_SIGN);
	}

	/*
	 * This is an indication for the NTLMSSP backend to
	 * also encrypt when only GENSEC_FEATURE_SIGN is requested
	 * in gensec_[un]wrap().
	 */
	gensec_want_feature(conn->gensec, GENSEC_FEATURE_LDAP_STYLE);

	if (conn->host) {
		status = gensec_set_target_hostname(conn->gensec, conn->host);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(1, ("Failed to set GENSEC target hostname: %s\n", 
				  nt_errstr(status)));
			goto failed;
		}
	}

	status = gensec_set_target_service(conn->gensec, "ldap");
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to set GENSEC target service: %s\n", 
			  nt_errstr(status)));
		goto failed;
	}

	status = gensec_start_mech_by_sasl_list(conn->gensec, sasl_names);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("None of the %d proposed SASL mechs were acceptable: %s\n",
			  count, nt_errstr(status)));
		goto failed;
	}

	while (1) {
		NTSTATUS gensec_status;
		struct ldap_message *response;
		struct ldap_message *msg;
		struct ldap_request *req;
		int result = LDAP_OTHER;
	
		status = gensec_update_ev(conn->gensec, tmp_ctx,
				       conn->event.event_ctx,
				       input,
				       &output);
		/* The status value here, from GENSEC is vital to the security
		 * of the system.  Even if the other end accepts, if GENSEC
		 * claims 'MORE_PROCESSING_REQUIRED' then you must keep
		 * feeding it blobs, or else the remote host/attacker might
		 * avoid mutal authentication requirements.
		 *
		 * Likewise, you must not feed GENSEC too much (after the OK),
		 * it doesn't like that either.
		 *
		 * For SASL/EXTERNAL, there is no data to send, but we still
		 * must send the actual Bind request the first time around.
		 * Otherwise, a result of NT_STATUS_OK with 0 output means the
		 * end of a multi-step authentication, and no message must be
		 * sent.
		 */

		gensec_status = status;

		if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) && 
		    !NT_STATUS_IS_OK(status)) {
			break;
		}
		if (NT_STATUS_IS_OK(status) && output.length == 0) {
			if (!first)
				break;
		}
		first = false;

		/* Perhaps we should make gensec_start_mech_by_sasl_list() return the name we got? */
		msg = new_ldap_sasl_bind_msg(tmp_ctx, conn->gensec->ops->sasl_name, (output.data?&output:NULL));
		if (msg == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}

		req = ldap_request_send(conn, msg);
		if (req == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}
		talloc_reparent(conn, tmp_ctx, req);

		status = ldap_result_n(req, 0, &response);
		if (!NT_STATUS_IS_OK(status)) {
			goto failed;
		}
		
		if (response->type != LDAP_TAG_BindResponse) {
			status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
			goto failed;
		}

		result = response->r.BindResponse.response.resultcode;

		if (result == LDAP_STRONG_AUTH_REQUIRED) {
			if (wrap_flags == 0) {
				wrap_flags = ADS_AUTH_SASL_SIGN;
				goto try_logon_again;
			}
		}

		if (result == LDAP_INVALID_CREDENTIALS) {
			/*
			  try a second time on invalid credentials, to
			  give the user a chance to re-enter the
			  password and to handle the case where our
			  kerberos ticket is invalid as the server
			  password has changed
			*/
			const char *principal;

			principal = gensec_get_target_principal(conn->gensec);
			if (principal == NULL) {
				const char *hostname = gensec_get_target_hostname(conn->gensec);
				const char *service  = gensec_get_target_service(conn->gensec);
				if (hostname != NULL && service != NULL) {
					principal = talloc_asprintf(tmp_ctx, "%s/%s", service, hostname);
				}
			}

			if (cli_credentials_failed_kerberos_login(creds, principal, &logon_retries) ||
			    cli_credentials_wrong_password(creds)) {
				/*
				  destroy our gensec session and loop
				  back up to the top to retry,
				  offering the user a chance to enter
				  new credentials, or get a new ticket
				  if using kerberos
				 */
				goto try_logon_again;
			}
		}

		if (result != LDAP_SUCCESS && result != LDAP_SASL_BIND_IN_PROGRESS) {
			status = ldap_check_response(conn, 
						     &response->r.BindResponse.response);
			break;
		}

		/* This is where we check if GENSEC wanted to be fed more data */
		if (!NT_STATUS_EQUAL(gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
			break;
		}
		if (response->r.BindResponse.SASL.secblob) {
			input = *response->r.BindResponse.SASL.secblob;
		} else {
			input = data_blob(NULL, 0);
		}
	}

	TALLOC_FREE(tmp_ctx);

	if (!NT_STATUS_IS_OK(status)) {
		goto failed;
	}

	conn->bind.type = LDAP_BIND_SASL;
	conn->bind.creds = creds;

	if (wrap_flags & ADS_AUTH_SASL_SEAL) {
		if (!gensec_have_feature(conn->gensec, GENSEC_FEATURE_SIGN)) {
			return NT_STATUS_INVALID_NETWORK_RESPONSE;
		}

		if (!gensec_have_feature(conn->gensec, GENSEC_FEATURE_SEAL)) {
			return NT_STATUS_INVALID_NETWORK_RESPONSE;
		}
	} else if (wrap_flags & ADS_AUTH_SASL_SIGN) {
		if (!gensec_have_feature(conn->gensec, GENSEC_FEATURE_SIGN)) {
			return NT_STATUS_INVALID_NETWORK_RESPONSE;
		}
	}

	if (!gensec_have_feature(conn->gensec, GENSEC_FEATURE_SIGN) &&
	    !gensec_have_feature(conn->gensec, GENSEC_FEATURE_SEAL)) {
		return NT_STATUS_OK;
	}

	status = gensec_create_tstream(conn->sockets.raw,
				       conn->gensec,
				       conn->sockets.raw,
				       &conn->sockets.sasl);
	if (!NT_STATUS_IS_OK(status)) {
		goto failed;
	}

	conn->sockets.active = conn->sockets.sasl;

	return NT_STATUS_OK;

failed:
	talloc_free(tmp_ctx);
	talloc_free(conn->gensec);
	conn->gensec = NULL;
	return status;
}