gristlabs_grist-core/app/server/lib/GranularAccess.ts
Paul Fitzpatrick a5744dadfb (core) refactor assertCanMaybeApplyUserActions
Summary: This refactors assertCanMaybeApplyUserActions for clarity.

Test Plan: existing tests pass, added test

Reviewers: dsagal, jarek

Reviewed By: dsagal, jarek

Subscribers: jarek

Differential Revision: https://phab.getgrist.com/D3637
2022-09-27 13:13:39 -04:00

2583 lines
108 KiB
TypeScript

import { ALL_PERMISSION_PROPS } from 'app/common/ACLPermissions';
import { ACLRuleCollection, SPECIAL_RULES_TABLE_ID } from 'app/common/ACLRuleCollection';
import { ActionGroup } from 'app/common/ActionGroup';
import { createEmptyActionSummary } from 'app/common/ActionSummary';
import { ServerQuery } from 'app/common/ActiveDocAPI';
import { ApiError } from 'app/common/ApiError';
import {
AddRecord,
BulkAddRecord,
BulkColValues,
BulkRemoveRecord,
BulkUpdateRecord,
} from 'app/common/DocActions';
import { RemoveRecord, ReplaceTableData, UpdateRecord } from 'app/common/DocActions';
import { CellValue, ColValues, DocAction, getTableId, isSchemaAction } from 'app/common/DocActions';
import { TableDataAction, UserAction } from 'app/common/DocActions';
import { DocData } from 'app/common/DocData';
import { UserOverride } from 'app/common/DocListAPI';
import { DocUsageSummary, FilteredDocUsageSummary } from 'app/common/DocUsage';
import { normalizeEmail } from 'app/common/emails';
import { ErrorWithCode } from 'app/common/ErrorWithCode';
import { AclMatchInput, InfoEditor, InfoView } from 'app/common/GranularAccessClause';
import { UserInfo } from 'app/common/GranularAccessClause';
import * as gristTypes from 'app/common/gristTypes';
import { getSetMapValue, isNonNullish, pruneArray } from 'app/common/gutil';
import { SingleCell } from 'app/common/TableData';
import { canEdit, canView, isValidRole, Role } from 'app/common/roles';
import { FullUser, UserAccessData } from 'app/common/UserAPI';
import { HomeDBManager } from 'app/gen-server/lib/HomeDBManager';
import { GristObjCode } from 'app/plugin/GristData';
import { compileAclFormula } from 'app/server/lib/ACLFormula';
import { DocClients } from 'app/server/lib/DocClients';
import { getDocSessionAccess, getDocSessionAltSessionId, getDocSessionUser,
OptDocSession } from 'app/server/lib/DocSession';
import { DocStorage } from 'app/server/lib/DocStorage';
import log from 'app/server/lib/log';
import { IPermissionInfo, PermissionInfo, PermissionSetWithContext } from 'app/server/lib/PermissionInfo';
import { TablePermissionSetWithContext } from 'app/server/lib/PermissionInfo';
import { integerParam } from 'app/server/lib/requestUtils';
import { getRelatedRows, getRowIdsFromDocAction } from 'app/server/lib/RowAccess';
import cloneDeep = require('lodash/cloneDeep');
import fromPairs = require('lodash/fromPairs');
import get = require('lodash/get');
// tslint:disable:no-bitwise
// Actions that add/update/remove/replace rows (DocActions only - UserActions
// may also result in row changes but are not in this list).
const ACTION_WITH_TABLE_ID = new Set(['AddRecord', 'BulkAddRecord', 'UpdateRecord', 'BulkUpdateRecord',
'RemoveRecord', 'BulkRemoveRecord',
'ReplaceTableData', 'TableData',
]);
type DataAction = AddRecord | BulkAddRecord | UpdateRecord | BulkUpdateRecord |
RemoveRecord | BulkRemoveRecord | ReplaceTableData | TableDataAction;
// Check if action adds/updates/removes/replaces rows.
function isDataAction(a: UserAction): a is DataAction {
return ACTION_WITH_TABLE_ID.has(String(a[0]));
}
function isAddRecordAction(a: DataAction): a is AddRecord | BulkAddRecord {
return ['AddRecord', 'BulkAddRecord'].includes(a[0]);
}
function isRemoveRecordAction(a: DataAction): a is RemoveRecord | BulkRemoveRecord {
return ['RemoveRecord', 'BulkRemoveRecord'].includes(a[0]);
}
function isBulkAction(a: DataAction): a is BulkAddRecord | BulkUpdateRecord |
BulkRemoveRecord | ReplaceTableData | TableDataAction {
return Array.isArray(a[2]);
}
// Check if a tableId is that of an ACL table. Currently just _grist_ACLRules and
// _grist_ACLResources are accepted.
function isAclTable(tableId: string): boolean {
return ['_grist_ACLRules', '_grist_ACLResources'].includes(tableId);
}
// A list of key metadata tables that need special handling. Other metadata tables may
// refer to material in some of these tables but don't need special handling.
// TODO: there are other metadata tables that would need access control, or redesign -
// specifically _grist_Attachments.
const STRUCTURAL_TABLES = new Set(['_grist_Tables', '_grist_Tables_column', '_grist_Views',
'_grist_Views_section', '_grist_Views_section_field',
'_grist_ACLResources', '_grist_ACLRules']);
// Actions that won't be allowed (yet) for a user with nuanced access to a document.
// A few may be innocuous, but that hasn't been figured out yet.
const SPECIAL_ACTIONS = new Set(['InitNewDoc',
'EvalCode',
'UpdateSummaryViewSection',
'DetachSummaryViewSection',
'GenImporterView',
'MakeImportTransformColumns',
'FillTransformRuleColIds',
'TransformAndFinishImport',
'AddView',
'CopyFromColumn',
'ConvertFromColumn',
'AddHiddenColumn',
'RespondToRequests',
]);
// Odd-ball actions marked as deprecated or which seem unlikely to be used.
const SURPRISING_ACTIONS = new Set([
'RemoveView',
'AddViewSection',
]);
// Actions we'll allow unconditionally for now.
const OK_ACTIONS = new Set(['Calculate', 'UpdateCurrentTime']);
// Other actions that are believed to be compatible with granular access.
// Only add an action to OTHER_RECOGNIZED_ACTIONS if you know access control
// has been handled for it, or it is clear that access control can be done
// by looking at the Create/Update/Delete permissions for the DocActions it
// will create. For example, at the time of writing CopyFromColumn should
// not be here, since it could read a column the user is not supposed to
// have access rights to, and it is not handled specially.
const OTHER_RECOGNIZED_ACTIONS = new Set([
// Data actions.
'AddRecord',
'BulkAddRecord',
'UpdateRecord',
'BulkUpdateRecord',
'RemoveRecord',
'BulkRemoveRecord',
'ReplaceTableData',
// A data action handled specially because of read needs.
'AddOrUpdateRecord',
// Groups of actions.
'ApplyDocActions',
'ApplyUndoActions',
// Column-level schema changes.
'AddColumn',
'AddVisibleColumn',
'RemoveColumn',
'RenameColumn',
'ModifyColumn',
// Table-level schema changes.
'AddEmptyTable',
'AddTable',
'AddRawTable',
'RemoveTable',
'RenameTable',
// Display column support.
'SetDisplayFormula',
'MaybeCopyDisplayFormula',
// Sundry misc.
'RenameChoices',
'AddEmptyRule',
'CreateViewSection',
'RemoveViewSection',
]);
interface DocUpdateMessage {
actionGroup: ActionGroup;
docActions: DocAction[];
docUsage: DocUsageSummary;
}
/**
* Granular access for a single bundle, in different phases.
*/
export interface GranularAccessForBundle {
canApplyBundle(): Promise<void>;
appliedBundle(): Promise<void>;
finishedBundle(): Promise<void>;
sendDocUpdateForBundle(actionGroup: ActionGroup, docUsage: DocUsageSummary): Promise<void>;
}
/**
*
* Manage granular access to a document. This allows nuances other than the coarse
* owners/editors/viewers distinctions. Nuances are stored in the _grist_ACLResources
* and _grist_ACLRules tables.
*
* When the document is being modified, the object's GranularAccess is called at various
* steps of the process to check access rights. The GranularAccess object stores some
* state for an in-progress modification, to allow some caching of calculations across
* steps and clients. We expect modifications to be serialized, and the following
* pattern of calls for modifications:
*
* - assertCanMaybeApplyUserActions(), called with UserActions for an initial access check.
* Since not all checks can be done without analyzing UserActions into DocActions,
* it is ok for this call to pass even if a more definitive test later will fail.
* - getGranularAccessForBundle(), called once a possible bundle has been prepared
* (the UserAction has been compiled to DocActions).
* - canApplyBundle(), called when DocActions have been produced from UserActions,
* but before those DocActions have been applied to the DB. If fails, the modification
* will be abandoned.
* - appliedBundle(), called when DocActions have been applied to the DB, but before
* those changes have been sent to clients.
* - sendDocUpdateforBundle() is called once a bundle has been applied, to notify
* client of changes.
* - finishedBundle(), called when completely done with modification and any needed
* client notifications, whether successful or failed.
*
*
*/
export class GranularAccess implements GranularAccessForBundle {
// The collection of all rules.
private _ruler = new Ruler(this);
// Cache of user attributes associated with the given docSession. It's a WeakMap, to allow
// garbage-collection once docSession is no longer in use.
private _userAttributesMap = new WeakMap<OptDocSession, UserAttributes>();
private _prevUserAttributesMap: WeakMap<OptDocSession, UserAttributes>|undefined;
// When broadcasting a sequence of DocAction[]s, this contains the state of
// affected rows for the relevant table before and after each DocAction. It
// may contain some unaffected rows as well.
private _steps: Promise<ActionStep[]>|null = null;
// Intermediate metadata and rule state, if needed.
private _metaSteps: Promise<MetaStep[]>|null = null;
// Access control is done sequentially, bundle by bundle. This is the current bundle.
private _activeBundle: {
docSession: OptDocSession,
userActions: UserAction[],
docActions: DocAction[],
isDirect: boolean[],
undo: DocAction[],
// Flag tracking whether a set of actions have been applied to the database or not.
applied: boolean,
// Flag for whether user actions mention a rule change (clients are asked to reload
// in this case).
hasDeliberateRuleChange: boolean,
// Flag for whether doc actions mention a rule change, even if passive due to
// schema changes.
hasAnyRuleChange: boolean,
}|null;
public constructor(
private _docData: DocData,
private _docStorage: DocStorage,
private _docClients: DocClients,
private _fetchQueryFromDB: (query: ServerQuery) => Promise<TableDataAction>,
private _recoveryMode: boolean,
private _homeDbManager: HomeDBManager | null,
private _docId: string) {
}
public getGranularAccessForBundle(docSession: OptDocSession, docActions: DocAction[], undo: DocAction[],
userActions: UserAction[], isDirect: boolean[]): void {
if (this._activeBundle) { throw new Error('Cannot start a bundle while one is already in progress'); }
// This should never happen - attempts to write to a pre-fork session should be
// caught by an Authorizer. But let's be paranoid, since we may be pretending to
// be an owner for granular access purposes, and owners can write if we're not
// careful!
if (docSession.forkingAsOwner) { throw new Error('Should never modify a prefork'); }
this._activeBundle = {
docSession, docActions, undo, userActions, isDirect,
applied: false, hasDeliberateRuleChange: false, hasAnyRuleChange: false
};
this._activeBundle.hasDeliberateRuleChange =
scanActionsRecursively(userActions, (a) => isAclTable(String(a[1])));
this._activeBundle.hasAnyRuleChange =
scanActionsRecursively(docActions, a => actionHasRuleChange(a));
}
/**
* Update granular access from DocData.
*/
public async update() {
await this._ruler.update(this._docData);
// Also clear the per-docSession cache of user attributes.
this._userAttributesMap = new WeakMap();
}
public getUser(docSession: OptDocSession): Promise<UserInfo> {
return this._getUser(docSession);
}
public async getCachedUser(docSession: OptDocSession): Promise<UserInfo> {
const access = await this._getAccess(docSession);
return access.getUser();
}
/**
* Check whether user has any access to table.
*/
public async hasTableAccess(docSession: OptDocSession, tableId: string) {
const pset = await this.getTableAccess(docSession, tableId);
return this.getReadPermission(pset) !== 'deny';
}
/**
* Get content of a given cell, if user has read access.
* Throws if not.
*/
public async getCellValue(docSession: OptDocSession, cell: SingleCell): Promise<CellValue> {
function fail(): never {
throw new ErrorWithCode('ACL_DENY', 'Cannot access cell');
}
const pset = await this.getTableAccess(docSession, cell.tableId);
const tableAccess = this.getReadPermission(pset);
if (tableAccess === 'deny') { fail(); }
const rows = await this._fetchQueryFromDB({
tableId: cell.tableId,
filters: { id: [cell.rowId] }
});
if (!rows || rows[2].length === 0) { fail(); }
const rec = new RecordView(rows, 0);
const input: AclMatchInput = {user: await this._getUser(docSession), rec, newRec: rec};
const rowPermInfo = new PermissionInfo(this._ruler.ruleCollection, input);
const rowAccess = rowPermInfo.getTableAccess(cell.tableId).perms.read;
if (rowAccess === 'deny') { fail(); }
if (rowAccess !== 'allow') {
const colAccess = rowPermInfo.getColumnAccess(cell.tableId, cell.colId).perms.read;
if (colAccess === 'deny') { fail(); }
}
const colValues = rows[3];
if (!(cell.colId in colValues)) { fail(); }
return rec.get(cell.colId);
}
/**
* Checks whether the specified cell is accessible by the user, and contains
* the specified attachment. Throws with ACL_DENY code if not.
*/
public async assertAttachmentAccess(docSession: OptDocSession, cell: SingleCell, attId: number): Promise<void> {
const value = await this.getCellValue(docSession, cell);
// Need to check column is actually an attachment column.
if (this._docStorage.getColumnType(cell.tableId, cell.colId) !== 'Attachments') {
throw new ErrorWithCode('ACL_DENY', 'not an attachment column');
}
// Check that material in cell includes the attachment.
if (!gristTypes.isList(value)) {
throw new ErrorWithCode('ACL_DENY', 'not a list');
}
if (value.indexOf(attId) <= 0) {
throw new ErrorWithCode('ACL_DENY', 'attachment not present in cell');
}
}
/**
* Called after UserAction[]s have been applied in the sandbox, and DocAction[]s have been
* computed, but before we have committed those DocAction[]s to the database. If this
* throws an exception, the sandbox changes will be reverted.
*/
public async canApplyBundle() {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const {docActions, docSession, isDirect} = this._activeBundle;
if (this._activeBundle.hasDeliberateRuleChange && !await this.isOwner(docSession)) {
throw new ErrorWithCode('ACL_DENY', 'Only owners can modify access rules');
}
// Normally, viewer requests would never reach this point, but they can happen
// using the "view as" functionality where user is an owner wanting to preview the
// access level of another. And again, the default access rules would normally
// forbid edit access to a viewer - but that can be overridden.
// An alternative to this check would be to sandwich user-defined access rules
// between some defaults. Currently the defaults have lower priority than
// user-defined access rules.
if (!canEdit(await this.getNominalAccess(docSession))) {
throw new ErrorWithCode('ACL_DENY', 'Only owners or editors can modify documents');
}
if (this._ruler.haveRules()) {
await Promise.all(
docActions.map((action, actionIdx) => {
if (isDirect[actionIdx]) {
return this._checkIncomingDocAction({docSession, action, actionIdx});
}
}));
}
if (this._recoveryMode) {
// Don't do any further checking in recovery mode.
return;
}
// If the actions change any rules, verify that we'll be able to handle the changed rules. If
// they are to cause an error, reject the action to avoid forcing user into recovery mode.
// WATCH OUT - this will trigger for "passive" changes caused by tableId/colId renames.
if (docActions.some(docAction => isAclTable(getTableId(docAction)))) {
// Create a tmpDocData with just the tables we care about, then update docActions to it.
const tmpDocData: DocData = new DocData(
(tableId) => { throw new Error("Unexpected DocData fetch"); }, {
_grist_Tables: this._docData.getMetaTable('_grist_Tables').getTableDataAction(),
_grist_Tables_column: this._docData.getMetaTable('_grist_Tables_column').getTableDataAction(),
_grist_ACLResources: this._docData.getMetaTable('_grist_ACLResources').getTableDataAction(),
_grist_ACLRules: this._docData.getMetaTable('_grist_ACLRules').getTableDataAction(),
});
for (const da of docActions) {
tmpDocData.receiveAction(da);
}
// Use the post-actions data to process the rules collection, and throw error if that fails.
const ruleCollection = new ACLRuleCollection();
await ruleCollection.update(tmpDocData, {log, compile: compileAclFormula});
if (ruleCollection.ruleError) {
throw new ApiError(ruleCollection.ruleError.message, 400);
}
try {
ruleCollection.checkDocEntities(tmpDocData);
} catch (err) {
throw new ApiError(err.message, 400);
}
}
}
/**
* This should be called after each action bundle has been applied to the database,
* but before the actions are broadcast to clients. It will set us up to be able
* to efficiently filter those broadcasts.
*
* We expect actions bundles for a document to be applied+broadcast serially (the
* broadcasts can be parallelized, but should complete before moving on to further
* document mutation).
*/
public async appliedBundle() {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const {docActions} = this._activeBundle;
this._activeBundle.applied = true;
if (!this._ruler.haveRules()) { return; }
// Check if a table that affects user attributes has changed. If so, put current
// attributes aside for later comparison, and clear cache.
const attrs = new Set([...this._ruler.ruleCollection.getUserAttributeRules().values()].map(r => r.tableId));
const attrChange = docActions.some(docAction => attrs.has(getTableId(docAction)));
if (attrChange) {
this._prevUserAttributesMap = this._userAttributesMap;
this._userAttributesMap = new WeakMap();
}
// If there's a schema change, zap permission cache.
const schemaChange = docActions.some(docAction => isSchemaAction(docAction));
if (attrChange || schemaChange) {
this._ruler.clearCache();
}
}
/**
* This should be called once an action bundle has been broadcast to
* all clients (or the bundle has been denied). It will clean up
* any temporary state cached for filtering those broadcasts.
*/
public async finishedBundle() {
if (!this._activeBundle) { return; }
if (this._activeBundle.applied) {
const {docActions} = this._activeBundle;
await this._updateRules(docActions);
}
this._steps = null;
this._metaSteps = null;
this._prevUserAttributesMap = undefined;
this._activeBundle = null;
}
/**
* Filter DocActions to be sent to a client.
*/
public async filterOutgoingDocActions(docSession: OptDocSession, docActions: DocAction[]): Promise<DocAction[]> {
// If the user requested a rule change, trigger a reload.
if (this._activeBundle?.hasDeliberateRuleChange) {
// TODO: could avoid reloading in many cases, especially for an owner who has full
// document access.
throw new ErrorWithCode('NEED_RELOAD', 'document needs reload, access rules changed');
}
// Optimize case where there are no rules to enforce.
if (!this._ruler.haveRules()) { return docActions; }
// If user attributes have changed, trigger a reload.
await this._checkUserAttributes(docSession);
const actions = await Promise.all(
docActions.map((action, actionIdx) => this._filterOutgoingDocAction({docSession, action, actionIdx})));
return ([] as DocAction[]).concat(...actions);
}
/**
* Filter an ActionGroup to be sent to a client.
*/
public async filterActionGroup(
docSession: OptDocSession,
actionGroup: ActionGroup,
options: {role?: Role | null} = {}
): Promise<ActionGroup> {
if (await this.allowActionGroup(docSession, actionGroup, options)) { return actionGroup; }
// For now, if there's any nuance at all, suppress the summary and description.
const result: ActionGroup = { ...actionGroup };
result.actionSummary = createEmptyActionSummary();
result.desc = '';
return result;
}
/**
* Check whether an ActionGroup can be sent to the client. TODO: in future, we'll want
* to filter acceptable parts of ActionGroup, rather than denying entirely.
*/
public async allowActionGroup(
docSession: OptDocSession,
_actionGroup: ActionGroup,
options: {role?: Role | null} = {}
): Promise<boolean> {
return this.canReadEverything(docSession, options);
}
/**
* Filter DocUsageSummary to be sent to a client.
*/
public async filterDocUsageSummary(
docSession: OptDocSession,
docUsage: DocUsageSummary,
options: {role?: Role | null} = {}
): Promise<FilteredDocUsageSummary> {
const result: FilteredDocUsageSummary = { ...docUsage };
const role = options.role ?? await this.getNominalAccess(docSession);
const hasEditRole = canEdit(role);
if (!hasEditRole) { result.dataLimitStatus = null; }
const hasFullReadAccess = await this.canReadEverything(docSession);
if (!hasEditRole || !hasFullReadAccess) {
result.rowCount = 'hidden';
result.dataSizeBytes = 'hidden';
result.attachmentsSizeBytes = 'hidden';
}
return result;
}
/**
* Check the list of UserActions, throwing if something not permitted is found.
* The data engine is the definitive interpreter of UserActions, but we do what
* we can, and then rely on analysis of DocActions produced by the data engine
* later to finish the job. Any actions that read data and expose it in some way
* need to be caught at this point, since that won't be evident in the DocActions.
* So far, we've been restricting the permitted combinations of UserActions when
* data is read to make access control tractable. Likewise, any actions that might
* result in running user code that would not eventually be permitted needs to be
* caught now, since by the time it hits the data engine it is too late.
*/
public async checkUserActions(docSession: OptDocSession, actions: UserAction[]): Promise<void> {
if (this._hasExceptionalFullAccess(docSession)) { return; }
// Checks are in no particular order.
await this._checkSimpleDataActions(docSession, actions);
await this._checkForSpecialOrSurprisingActions(docSession, actions);
await this._checkPossiblePythonFormulaModification(docSession, actions);
await this._checkAddOrUpdateAccess(docSession, actions);
}
/**
* Called when it is permissible to partially fulfill the requested actions.
* Will remove forbidden actions in a very limited set of recognized circumstances.
* In fact, currently in only one circumstance:
*
* - If there is a single requested action, and it is an ApplyUndoActions.
* The goal being to let a user undo their action to the extent that it
* is possible to do so.
*
* In this case, the list of actions nested in ApplyUndoActions will be extracted,
* treated as DocActions, and filtered to remove any component parts (at action,
* column, row, or individual cell level) that would be forbidden.
*
* Beyond pure data changes, there are no heroics - any schema change will
* result in prefiltering being skipped.
*
* Any filtering done here is NOT a security measure, and the output should
* not be granted any level of automatic trust.
*/
public async prefilterUserActions(docSession: OptDocSession, actions: UserAction[]): Promise<UserAction[]> {
// Currently we only attempt prefiltering for an ApplyUndoActions.
if (actions.length !== 1) { return actions; }
const userAction = actions[0];
if (userAction[0] !== 'ApplyUndoActions') { return actions; }
// Ok, this is an undo. Unpack the requested undo actions. For a bona
// fide ApplyUndoActions, these would be doc actions generated by the
// data engine and stored in action history. But there is no actual
// restriction in how ApplyUndoActions could be generated. Security
// is enforced separately, so we don't need to be paranoid here.
const docActions = userAction[1] as DocAction[];
// Bail out if there is any hint of a schema change.
// TODO: may want to also bail if an action we'd need to filter would
// affect a row id used later in the bundle. Perhaps prefiltering
// should be restricted to bundles of updates only for that reason.
for (const action of docActions) {
if (!isDataAction(action) || getTableId(action).startsWith('_grist')) {
return actions;
}
}
// Run through a simulation of access control on these actions,
// retaining only permitted material.
const proposedActions: UserAction[] = [];
try {
// Establish our doc actions as the current context for access control.
// We don't have undo information for them, but don't need to because
// they have not been applied to the db. Treat all actions as "direct"
// since we could not trust claims of indirectness currently in
// any case (though we could rearrange to limit how undo actions are
// requested).
this.getGranularAccessForBundle(docSession, docActions, [], docActions,
docActions.map(() => true));
for (const [actionIdx, action] of docActions.entries()) {
// A single action might contain forbidden material at cell, row, column,
// or table level. Retaining permitted material may require refactoring the
// single action into a series of actions.
try {
await this._checkIncomingDocAction({docSession, action, actionIdx});
// Nothing forbidden! Keep this action unchanged.
proposedActions.push(action);
} catch (e) {
if (String(e.code) !== 'ACL_DENY') { throw e; }
const acts = await this._prefilterDocAction({docSession, action, actionIdx});
proposedActions.push(...acts);
// Presumably we've changed the action. Zap our cache of intermediate
// states, since it is stale now. TODO: reorganize cache to so can avoid wasting
// time repeating work unnecessarily. The cache was designed with all-or-nothing
// operations in mind, and is poorly suited to prefiltering.
// Note: the meaning of newRec is slippery in prefiltering, since it depends on
// state at the end of the bundle, but that state is unstable now.
// TODO look into prefiltering in cases using newRec in a many-action bundle.
this._steps = null;
this._metaSteps = null;
}
}
} finally {
await this.finishedBundle();
}
return [['ApplyUndoActions', proposedActions]];
}
/**
* For changes that could include Python formulas, check for schema access early.
*/
public needEarlySchemaPermission(a: UserAction|DocAction): boolean {
const name = a[0] as string;
if (name === 'ModifyColumn' || name === 'SetDisplayFormula') {
return true;
} else if (isDataAction(a)) {
const tableId = getTableId(a);
if (tableId === '_grist_Tables_column' || tableId === '_grist_Validations') {
return true;
}
}
return false;
}
/**
* Check whether access is simple, or there are granular nuances that need to be
* worked through. Currently if there are no owner-only tables, then everyone's
* access is simple and without nuance.
*/
public async hasNuancedAccess(docSession: OptDocSession): Promise<boolean> {
if (!this._ruler.haveRules()) { return false; }
return !await this.hasFullAccess(docSession);
}
/**
* Check if user is explicitly permitted to download/copy document.
* They may be allowed to download in any case, see canCopyEverything.
*/
public async hasFullCopiesPermission(docSession: OptDocSession): Promise<boolean> {
const permInfo = await this._getAccess(docSession);
return permInfo.getColumnAccess(SPECIAL_RULES_TABLE_ID, 'FullCopies').perms.read === 'allow';
}
/**
* Check if user may view Access Rules.
*/
public async hasAccessRulesPermission(docSession: OptDocSession): Promise<boolean> {
const permInfo = await this._getAccess(docSession);
return permInfo.getColumnAccess(SPECIAL_RULES_TABLE_ID, 'AccessRules').perms.read === 'allow';
}
/**
* Check whether user can read everything in document. Checks both home-level and doc-level
* permissions.
*/
public async canReadEverything(
docSession: OptDocSession,
options: {role?: Role | null} = {}
): Promise<boolean> {
const access = options.role ?? await this.getNominalAccess(docSession);
if (!canView(access)) { return false; }
const permInfo = await this._getAccess(docSession);
return this.getReadPermission(permInfo.getFullAccess()) === 'allow';
}
/**
* An odd little right for findColFromValues and autocomplete. Allow if user can read
* all data, or is an owner. Might be worth making a special permission.
*/
public async canScanData(docSession: OptDocSession): Promise<boolean> {
return await this.isOwner(docSession) || await this.canReadEverything(docSession);
}
/**
* Check whether user can copy everything in document. Owners can always copy
* everything, even if there are rules that specify they cannot.
*
* There's a small wrinkle about access rules. The content
* of _grist_ACLRules and Resources are only send to clients that are owners,
* but could be copied by others by other means (e.g. download) as long as all
* tables or columns are readable. This seems ok (no private info involved),
* just a bit inconsistent.
*/
public async canCopyEverything(docSession: OptDocSession): Promise<boolean> {
return await this.hasFullCopiesPermission(docSession) ||
await this.canReadEverything(docSession);
}
/**
* Check whether user has full access to the document. Currently that is interpreted
* as equivalent owner-level access to the document.
* TODO: uses of this method should be checked to see if they can be fleshed out
* now we have more of the ACL implementation done.
*/
public hasFullAccess(docSession: OptDocSession): Promise<boolean> {
return this.isOwner(docSession);
}
/**
* Check whether user has owner-level access to the document.
*/
public async isOwner(docSession: OptDocSession): Promise<boolean> {
const access = await this.getNominalAccess(docSession);
return access === 'owners';
}
/**
*
* If the user does not have access to the full document, we need to filter out
* parts of the document metadata. For simplicity, we overwrite rather than
* filter for now, so that the overall structure remains consistent. We overwrite:
*
* - names, textual ids, formulas, and other textual options
* - foreign keys linking columns/views/sections back to a forbidden table
*
* On the client, a page with a blank name will be marked gracefully as unavailable.
*
* Some information leaks, for example the existence of private tables and how
* many columns they had, and something of the relationships between them. Long term,
* it could be better to zap rows entirely, and do the work of cleaning up any cross
* references to them.
*
*/
public async filterMetaTables(docSession: OptDocSession,
tables: {[key: string]: TableDataAction}): Promise<{[key: string]: TableDataAction}> {
// If user has right to read everything, return immediately.
if (await this.canReadEverything(docSession)) { return tables; }
// If we are going to modify metadata, make a copy.
tables = cloneDeep(tables);
const permInfo = await this._getAccess(docSession);
const censor = new CensorshipInfo(permInfo, this._ruler.ruleCollection, tables,
await this.hasAccessRulesPermission(docSession));
for (const tableId of STRUCTURAL_TABLES) {
censor.apply(tables[tableId]);
}
return tables;
}
/**
* Distill the clauses for the given session and table, to figure out the
* access level and any row-level access functions needed.
*/
public async getTableAccess(docSession: OptDocSession, tableId: string): Promise<TablePermissionSetWithContext> {
if (this._hasExceptionalFullAccess(docSession)) {
return {
perms: {read: 'allow', create: 'allow', delete: 'allow', update: 'allow', schemaEdit: 'allow'},
ruleType: 'table',
getMemos() { throw new Error('never needed'); }
};
}
return (await this._getAccess(docSession)).getTableAccess(tableId);
}
/**
* Modify table data in place, removing any rows or columns to which access
* is not granted.
*/
public async filterData(docSession: OptDocSession, data: TableDataAction) {
const permInfo = await this._getAccess(docSession);
const cursor: ActionCursor = {docSession, action: data, actionIdx: null};
const tableId = getTableId(data);
if (this.getReadPermission(permInfo.getTableAccess(tableId)) === 'mixed') {
const readAccessCheck = this._readAccessCheck(docSession);
await this._filterRowsAndCells(cursor, data, data, readAccessCheck, {allowRowRemoval: true});
}
// Filter columns, omitting any to which the user has no access, regardless of rows.
this._filterColumns(
data[3],
(colId) => this.getReadPermission(permInfo.getColumnAccess(tableId, colId)) !== 'deny');
}
public async getUserOverride(docSession: OptDocSession): Promise<UserOverride|undefined> {
await this._getUser(docSession);
return this._getUserAttributes(docSession).override;
}
public getReadPermission(ps: PermissionSetWithContext) {
return ps.perms.read;
}
public assertCanRead(ps: PermissionSetWithContext) {
accessChecks.fatal.read.get(ps);
}
/**
* Broadcast document changes to all clients, with appropriate filtering.
*/
public async sendDocUpdateForBundle(actionGroup: ActionGroup, docUsage: DocUsageSummary) {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const { docActions, docSession } = this._activeBundle;
const client = docSession && docSession.client || null;
const message: DocUpdateMessage = { actionGroup, docActions, docUsage };
await this._docClients.broadcastDocMessage(client, 'docUserAction',
message,
(_docSession) => this._filterDocUpdate(_docSession, message));
}
// Remove cached access information for a given session.
public flushAccess(docSession: OptDocSession) {
this._ruler.flushAccess(docSession);
this._userAttributesMap.delete(docSession);
this._prevUserAttributesMap?.delete(docSession);
}
// Get a set of example users for playing with access control.
// We use the example.com domain, which is reserved for uses like this.
public getExampleViewAsUsers(): UserAccessData[] {
return [
{id: 0, email: 'owner@example.com', name: 'Owner', access: 'owners'},
{id: 0, email: 'editor1@example.com', name: 'Editor 1', access: 'editors'},
{id: 0, email: 'editor2@example.com', name: 'Editor 2', access: 'editors'},
{id: 0, email: 'viewer@example.com', name: 'Viewer', access: 'viewers'},
{id: 0, email: 'unknown@example.com', name: 'Unknown User', access: null},
];
}
// Compile a list of users mentioned in user attribute tables keyed by email.
// If there is a Name column or an Access column, in the table, we use them.
public async collectViewAsUsersFromUserAttributeTables(): Promise<Array<Partial<UserAccessData>>> {
const result: Array<Partial<UserAccessData>> = [];
for (const clause of this._ruler.ruleCollection.getUserAttributeRules().values()) {
if (clause.charId !== 'Email') { continue; }
try {
const users = await this._fetchQueryFromDB({
tableId: clause.tableId,
filters: {},
});
const user = new RecordView(users, undefined);
const count = users[2].length;
for (let i = 0; i < count; i++) {
user.index = i;
const email = user.get(clause.lookupColId);
const name = user.get('Name') || String(email).split('@')[0];
const access = user.has('Access') ? String(user.get('Access')) : 'editors';
result.push({
email: email ? String(email) : undefined,
name: name ? String(name) : undefined,
access: isValidRole(access) ? access : null, // 'null' -> null a bit circuitously
});
}
} catch (e) {
log.warn(`User attribute ${clause.name} failed`, e);
}
}
return result;
}
/**
* Get the role the session user has for this document. User may be overridden,
* in which case the role of the override is returned.
* The forkingAsOwner flag of docSession should not be respected for non-owners,
* so that the pseudo-ownership it offers is restricted to granular access within a
* document (as opposed to document-level operations).
*/
public async getNominalAccess(docSession: OptDocSession): Promise<Role|null> {
const linkParameters = docSession.authorizer?.getLinkParameters() || {};
const baseAccess = getDocSessionAccess(docSession);
if ((linkParameters.aclAsUserId || linkParameters.aclAsUser) && baseAccess === 'owners') {
const info = await this._getUser(docSession);
return info.Access;
}
return baseAccess;
}
/**
* An optimization to catch obvious access problems for simple data
* actions (such as UpdateRecord, BulkAddRecord, etc) early. Checks
* actions one by one (nesting into ApplyUndoActions and
* ApplyDocActions as needed) until meeting one that isn't a simple
* data action. Checks are crude, and limited to the table access
* level. Returns true if all actions were checked, false if
* not. Returning true does not imply the actions in the bundle are
* permissible; returning false does not imply they should be
* denied. Throwing an error DOES imply that an action was
* encountered that should be denied.
*/
private async _checkSimpleDataActions(docSession: OptDocSession, actions: UserAction[]): Promise<boolean> {
for (const action of actions) {
if (!await this._checkSimpleDataAction(docSession, action)) {
return false;
}
}
return true;
}
/**
* Throws an error for simple data actions that the user cannot perform.
* Checking is only at the table level. Returns true if the action clearly
* does not change the document schema or metadata, otherwise false if it might.
*/
private async _checkSimpleDataAction(docSession: OptDocSession, a: UserAction|DocAction): Promise<boolean> {
const name = a[0] as string;
if (name === 'ApplyUndoActions') {
return this._checkSimpleDataActions(docSession, a[1] as UserAction[]);
} else if (name === 'ApplyDocActions') {
return this._checkSimpleDataActions(docSession, a[1] as UserAction[]);
} else if (isDataAction(a)) {
const tableId = getTableId(a);
if (tableId.startsWith('_grist_')) {
return false;
}
const tableAccess = await this.getTableAccess(docSession, tableId);
const accessCheck = await this._getAccessForActionType(docSession, a, 'fatal');
accessCheck.get(tableAccess); // will throw if access denied.
return true;
} else {
// Any other action might change schema, so continuing could lead
// to false detections of failures. For example, renaming a column
// and then updating cells within it should be allowed.
return false;
}
}
private async _checkForSpecialOrSurprisingActions(docSession: OptDocSession,
actions: UserAction[]) {
await applyToActionsRecursively(actions, async (a) => {
const name = String(a[0]);
if (SPECIAL_ACTIONS.has(name)) {
if (await this.hasNuancedAccess(docSession)) {
throw new ErrorWithCode('ACL_DENY', `Blocked by access rules: '${name}' actions need uncomplicated access`);
}
} else if (SURPRISING_ACTIONS.has(name)) {
if (!await this.hasFullAccess(docSession)) {
throw new ErrorWithCode('ACL_DENY', `Blocked by access rules: '${name}' actions need full access`);
}
} else if (OK_ACTIONS.has(name)) {
// fine, anyone can do these at any time, continue.
} else if (OTHER_RECOGNIZED_ACTIONS.has(name)) {
// these are known actions that have not been specifically classified.
} else {
// we've hit something unexpected - perhaps a UserAction has been added
// without considering access control.
throw new ErrorWithCode('ACL_DENY', `Blocked by access rules: '${name}' actions are not controlled`);
}
});
}
// AddOrUpdateRecord requires broad read access to a table.
// But tables can be renamed, and access can be granted and removed
// within a bundle.
//
// For now, we forbid the combination of AddOrUpdateRecord and
// with actions other than other AddOrUpdateRecords, or simple data
// changes.
//
// Access rules and user attributes might change during the bundle.
// We deny based on access rights at the beginning of the bundle,
// as for _checkPossiblePythonFormulaModification. This is on the
// theory that someone who can change access rights can do anything.
//
// There might be uses for applying AddOrUpdateRecord in a nuanced
// way within the scope of what a user can read, but there's no easy
// way to do that within the data engine as currently
// formulated. Could perhaps be done for on-demand tables though.
private async _checkAddOrUpdateAccess(docSession: OptDocSession, actions: UserAction[]) {
if (!scanActionsRecursively(actions, (a) => a[0] === 'AddOrUpdateRecord')) {
// Don't need to apply this particular check.
return;
}
// Fail if being combined with anything fancy.
if (scanActionsRecursively(actions, (a) => {
const name = a[0];
return !['ApplyUndoActions', 'ApplyDocActions', 'AddOrUpdateRecord'].includes(String(name)) &&
!(isDataAction(a) && !getTableId(a).startsWith('_grist_'));
})) {
throw new Error('Can only combine AddOrUpdate with simple data changes');
}
// Check for read access, and that we're not touching metadata.
await applyToActionsRecursively(actions, async (a) => {
if (a[0] !== 'AddOrUpdateRecord') { return; }
const tableId = validTableIdString(a[1]);
if (tableId.startsWith('_grist_')) {
throw new Error(`AddOrUpdate cannot yet be used on metadata tables`);
}
const tableAccess = await this.getTableAccess(docSession, tableId);
accessChecks.fatal.read.throwIfNotFullyAllowed(tableAccess);
accessChecks.fatal.update.throwIfDenied(tableAccess);
accessChecks.fatal.create.throwIfDenied(tableAccess);
});
}
private async _checkPossiblePythonFormulaModification(docSession: OptDocSession, actions: UserAction[]) {
// If changes could include Python formulas, then user must have
// +S before we even consider passing these to the data engine.
// Since we don't track rule or schema changes at this stage, we
// approximate with the user's access rights at beginning of
// bundle.
if (scanActionsRecursively(actions, (a) => this.needEarlySchemaPermission(a))) {
await this._assertSchemaAccess(docSession);
}
}
/**
* Asserts that user has schema access.
*/
private async _assertSchemaAccess(docSession: OptDocSession) {
if (this._hasExceptionalFullAccess(docSession)) { return; }
const permInfo = await this._getAccess(docSession);
accessChecks.fatal.schemaEdit.throwIfDenied(permInfo.getFullAccess());
}
// The AccessCheck for the "read" permission is used enough to merit a shortcut.
// We just need to be careful to retain unfettered access for exceptional sessions.
private _readAccessCheck(docSession: OptDocSession): IAccessCheck {
return this._hasExceptionalFullAccess(docSession) ? dummyAccessCheck : accessChecks.check.read;
}
// Return true for special system sessions or document-creation sessions, where
// unfettered access is appropriate.
private _hasExceptionalFullAccess(docSession: OptDocSession): Boolean {
return docSession.mode === 'system' || docSession.mode === 'nascent';
}
/**
* This filters a message being broadcast to all clients to be appropriate for one
* particular client, if that client may need some material filtered out.
*/
private async _filterDocUpdate(docSession: OptDocSession, message: DocUpdateMessage) {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const role = await this.getNominalAccess(docSession);
const result = {
...message,
docUsage: await this.filterDocUsageSummary(docSession, message.docUsage, {role}),
};
if (!this._ruler.haveRules() && !this._activeBundle.hasDeliberateRuleChange) {
return result;
}
result.actionGroup = await this.filterActionGroup(docSession, message.actionGroup, {role});
result.docActions = await this.filterOutgoingDocActions(docSession, message.docActions);
if (result.docActions.length === 0) { return null; }
return result;
}
private async _updateRules(docActions: DocAction[]) {
// If there is a rule change, redo from scratch for now.
// TODO: this is placeholder code. Should deal with connected clients.
if (docActions.some(docAction => isAclTable(getTableId(docAction)))) {
await this.update();
return;
}
if (!this._ruler.haveRules()) { return; }
// If there is a schema change, redo from scratch for now.
if (docActions.some(docAction => isSchemaAction(docAction))) {
await this.update();
}
}
/**
* Strip out any denied columns from an action. Returns null if nothing is left.
* accessCheck may throw if denials are fatal.
*/
private _pruneColumns(a: DocAction, permInfo: IPermissionInfo, tableId: string,
accessCheck: IAccessCheck): DocAction|null {
if (a[0] === 'RemoveRecord' || a[0] === 'BulkRemoveRecord') {
return a;
} else if (a[0] === 'AddRecord' || a[0] === 'BulkAddRecord' || a[0] === 'UpdateRecord' ||
a[0] === 'BulkUpdateRecord' || a[0] === 'ReplaceTableData' || a[0] === 'TableData') {
const na = cloneDeep(a);
this._filterColumns(na[3], (colId) => accessCheck.get(permInfo.getColumnAccess(tableId, colId)) !== 'deny');
if (Object.keys(na[3]).length === 0) { return null; }
return na;
} else if (a[0] === 'AddColumn' || a[0] === 'RemoveColumn' || a[0] === 'RenameColumn' ||
a[0] === 'ModifyColumn') {
const colId: string = a[2];
if (accessCheck.get(permInfo.getColumnAccess(tableId, colId)) === 'deny') { return null; }
} else {
// Remaining cases of AddTable, RemoveTable, RenameTable should have
// been handled at the table level.
}
return a;
}
/**
* Strip out any denied rows from an action. The action may be rewritten if rows
* become allowed or denied during the action. An action to add newly-allowed
* rows may be included, or an action to remove newly-forbidden rows. The result
* is a list rather than a single action. It may be the empty list.
*/
private async _pruneRows(cursor: ActionCursor): Promise<DocAction[]> {
const {action} = cursor;
// This only deals with Record-related actions.
if (!isDataAction(action)) { return [action]; }
// Get before/after state for this action. Broadcasts to other users can make use of the
// same state, so we share it (and only compute it if needed).
const {rowsBefore, rowsAfter} = await this._getRowsBeforeAndAfter(cursor);
// Figure out which rows were forbidden to this session before this action vs
// after this action. We need to know both so that we can infer the state of the
// client and send the correct change.
const orderedIds = getRowIdsFromDocAction(action);
const ids = new Set(orderedIds);
const forbiddenBefores = new Set(await this._getForbiddenRows(cursor, rowsBefore, ids));
const forbiddenAfters = new Set(await this._getForbiddenRows(cursor, rowsAfter, ids));
/**
* For rows forbidden before and after: just remove them.
* For rows allowed before and after: just leave them unchanged.
* For rows that were allowed before and are now forbidden:
* - strip them from the current action.
* - add a BulkRemoveRecord for them.
* For rows that were forbidden before and are now allowed:
* - remove them from the current action.
* - add a BulkAddRecord for them.
*/
const removals = new Set<number>(); // rows to remove from current action.
const forceAdds = new Set<number>(); // rows to add, that were previously stripped.
const forceRemoves = new Set<number>(); // rows to remove, that have become forbidden.
for (const id of ids) {
const forbiddenBefore = forbiddenBefores.has(id);
const forbiddenAfter = forbiddenAfters.has(id);
if (!forbiddenBefore && !forbiddenAfter) { continue; }
if (forbiddenBefore && forbiddenAfter) {
removals.add(id);
continue;
}
// If we reach here, then access right to the row changed and we have fancy footwork to do.
if (forbiddenBefore) {
// The row was forbidden and now is allowed. That's trivial if the row was just added.
if (action[0] === 'AddRecord' || action[0] === 'BulkAddRecord' ||
action[0] === 'ReplaceTableData' || action[0] === 'TableData') {
continue;
}
// Otherwise, strip the row from the current action.
removals.add(id);
if (action[0] === 'UpdateRecord' || action[0] === 'BulkUpdateRecord') {
// For updates, we need to send the entire row as an add, since the client
// doesn't know anything about it yet.
forceAdds.add(id);
} else {
// Remaining cases are [Bulk]RemoveRecord.
}
} else {
// The row was allowed and now is forbidden.
// If the action is a removal, that is just right.
if (action[0] === 'RemoveRecord' || action[0] === 'BulkRemoveRecord') { continue; }
// Otherwise, strip the row from the current action.
removals.add(id);
if (action[0] === 'UpdateRecord' || action[0] === 'BulkUpdateRecord') {
// For updates, we need to remove the entire row.
forceRemoves.add(id);
} else {
// Remaining cases are add-like actions.
}
}
}
// Execute our cunning plans for DocAction revisions.
const revisedDocActions = [
this._makeAdditions(rowsAfter, forceAdds),
this._removeRows(action, removals),
this._makeRemovals(rowsAfter, forceRemoves),
].filter(isNonNullish);
// Check whether there are column rules for this table, and if so whether they are row
// dependent. If so, we may need to update visibility of cells not mentioned in the
// original DocAction.
// No censorship is done here, all we do at this point is pull in any extra cells that need
// to be updated for the current client. Censorship for these cells, and any cells already
// present in the DocAction, is done by _filterRowsAndCells.
const ruler = await this._getRuler(cursor);
const tableId = getTableId(action);
const ruleSets = ruler.ruleCollection.getAllColumnRuleSets(tableId);
const colIds = new Set(([] as string[]).concat(
...ruleSets.map(ruleSet => ruleSet.colIds === '*' ? [] : ruleSet.colIds)
));
const access = await ruler.getAccess(cursor.docSession);
// Check columns in a consistent order, for determinism (easier testing).
// TODO: could pool some work between columns by doing them together rather than one by one.
for (const colId of [...colIds].sort()) {
// If the column is already in the DocAction, we can skip checking if we need to add it.
if (!action[3] || (colId in action[3])) { continue; }
// If the column is not row dependent, we have nothing to do.
if (access.getColumnAccess(tableId, colId).perms.read !== 'mixed') { continue; }
// Check column accessibility before and after.
const _forbiddenBefores = new Set(await this._getForbiddenRows(cursor, rowsBefore, ids, colId));
const _forbiddenAfters = new Set(await this._getForbiddenRows(cursor, rowsAfter, ids, colId));
// For any column that is in a visible row and for which accessibility has changed,
// pull it into the doc actions. We don't censor cells yet, that happens later
// (if that's what needs doing).
const changedIds = orderedIds.filter(id => !forceRemoves.has(id) && !removals.has(id) &&
(_forbiddenBefores.has(id) !== _forbiddenAfters.has(id)));
if (changedIds.length > 0) {
revisedDocActions.push(this._makeColumnUpdate(rowsAfter, colId, new Set(changedIds)));
}
}
// Return the results, also applying any cell-level access control.
const readAccessCheck = this._readAccessCheck(cursor.docSession);
const filteredDocActions: DocAction[] = [];
for (const a of revisedDocActions) {
const {filteredAction} =
await this._filterRowsAndCells({...cursor, action: a}, rowsAfter, rowsAfter, readAccessCheck,
{allowRowRemoval: false, copyOnModify: true});
if (filteredAction) { filteredDocActions.push(filteredAction); }
}
return filteredDocActions;
}
/**
* Like _pruneRows, but fails immediately if access to any row is forbidden.
* The accessCheck supplied should throw an error on denial.
*/
private async _checkRows(cursor: ActionCursor, accessCheck: IAccessCheck): Promise<void> {
const {action} = cursor;
// This check applies to data changes only.
if (!isDataAction(action)) { return; }
const {rowsBefore, rowsAfter} = await this._getRowsForRecAndNewRec(cursor);
// If any change is needed, this call will fail immediately because we are using
// access checks that throw.
await this._filterRowsAndCells(cursor, rowsBefore, rowsAfter, accessCheck,
{allowRowRemoval: false});
}
private async _getRowsBeforeAndAfter(cursor: ActionCursor) {
const {rowsBefore, rowsAfter} = await this._getStep(cursor);
if (!rowsBefore || !rowsAfter) { throw new Error('Logic error: no rows available'); }
return {rowsBefore, rowsAfter};
}
private async _getRowsForRecAndNewRec(cursor: ActionCursor) {
const steps = await this._getSteps();
if (cursor.actionIdx === null) { throw new Error('No step available'); }
const {rowsBefore, rowsLast} = steps[cursor.actionIdx];
if (!rowsBefore) { throw new Error('Logic error: no previous rows available'); }
if (rowsLast) {
return {rowsBefore, rowsAfter: rowsLast};
}
// When determining whether to apply an action, we choose to make newRec refer to the
// state at the end of the entire bundle. So we look for the last pair of row snapshots
// for the same table.
// TODO: there's a problem that this could alias rows if row ids were reused within the
// same bundle. It is kind of a slippery idea. Likewise, column renames are slippery.
// We could solve a lot of slipperiness by having newRec not transition across schema
// changes, but we don't really have the option because formula updates happen late.
let tableId = getTableId(rowsBefore);
let last = cursor.actionIdx;
for (let i = last + 1; i < steps.length; i++) {
const act = steps[i].action;
if (getTableId(act) !== tableId) { continue; }
if (act[0] === 'RenameTable') {
tableId = act[2];
continue;
}
last = i;
}
const rowsAfter = steps[cursor.actionIdx].rowsLast = steps[last].rowsAfter;
if (!rowsAfter) { throw new Error('Logic error: no next rows available'); }
return {rowsBefore, rowsAfter};
}
/**
* Scrub any rows and cells to which access is not granted from an
* action. Returns filteredAction, which is the provided action, a
* modified copy of the provided action, or null. It is null if the
* action was entirely eliminated (and was not a bulk action). It is
* a modified copy if any scrubbing was needed and copyOnModify is
* set, otherwise the original is modified in place.
*
* Also returns censoredRows, a set of indexes of rows that have a
* censored value in them.
*
* If allowRowRemoval is false, then rows will not be removed, and if the user
* does not have access to a row and the action itself is not a remove action, then
* an error will be thrown. This flag setting is used when filtering outgoing
* actions, where actions need rewriting elsewhere to reflect access changes to
* rows for each individual client.
*/
private async _filterRowsAndCells(cursor: ActionCursor, rowsBefore: TableDataAction, rowsAfter: TableDataAction,
accessCheck: IAccessCheck,
options: {
allowRowRemoval?: boolean,
copyOnModify?: boolean,
}): Promise<{
filteredAction: DocAction | null,
censoredRows: Set<number>
}> {
const censoredRows = new Set<number>();
const ruler = await this._getRuler(cursor);
const {docSession, action} = cursor;
if (action && isSchemaAction(action)) {
return {filteredAction: action, censoredRows};
}
let filteredAction: DocAction | null = action;
// For user convenience, for creations and deletions we equate rec and newRec.
// This makes writing rules that control multiple permissions easier to write in
// practice.
let rowsRec = rowsBefore;
let rowsNewRec = rowsAfter;
if (isAddRecordAction(action)) {
rowsRec = rowsAfter;
} else if (isRemoveRecordAction(action)) {
rowsNewRec = rowsBefore;
}
const rec = new RecordView(rowsRec, undefined);
const newRec = new RecordView(rowsNewRec, undefined);
const input: AclMatchInput = {user: await this._getUser(docSession), rec, newRec};
const [, tableId, , colValues] = action;
let filteredColValues: ColValues | BulkColValues | undefined | null = null;
const rowIds = getRowIdsFromDocAction(action);
const toRemove: number[] = [];
// Call this to make sure we are modifying a copy, not the original, if copyOnModify is set.
const copyOnNeed = () => {
if (filteredColValues === null) {
filteredAction = options?.copyOnModify ? cloneDeep(action) : action;
filteredColValues = filteredAction[3];
}
return filteredColValues;
};
let censorAt: (colId: string, idx: number) => void;
if (colValues === undefined) {
censorAt = () => 1;
} else if (Array.isArray(action[2])) {
censorAt = (colId, idx) => (copyOnNeed() as BulkColValues)[colId][idx] = [GristObjCode.Censored];
} else {
censorAt = (colId) => (copyOnNeed() as ColValues)[colId] = [GristObjCode.Censored];
}
// These map an index of a row in the action to its index in rowsBefore and in rowsAfter.
let getRecIndex: (idx: number) => number|undefined = (idx) => idx;
let getNewRecIndex: (idx: number) => number|undefined = (idx) => idx;
if (action !== rowsRec) {
const recIndexes = new Map(rowsRec[2].map((rowId, idx) => [rowId, idx]));
getRecIndex = (idx) => recIndexes.get(rowIds[idx]);
}
if (action !== rowsNewRec) {
const newRecIndexes = new Map(rowsNewRec[2].map((rowId, idx) => [rowId, idx]));
getNewRecIndex = (idx) => newRecIndexes.get(rowIds[idx]);
}
for (let idx = 0; idx < rowIds.length; idx++) {
rec.index = getRecIndex(idx);
newRec.index = getNewRecIndex(idx);
const rowPermInfo = new PermissionInfo(ruler.ruleCollection, input);
// getTableAccess() evaluates all column rules for THIS record. So it's really rowAccess.
const rowAccess = rowPermInfo.getTableAccess(tableId);
const access = accessCheck.get(rowAccess);
if (access === 'deny') {
toRemove.push(idx);
} else if (access !== 'allow' && colValues) {
// Go over column rules.
for (const colId of Object.keys(colValues)) {
const colAccess = rowPermInfo.getColumnAccess(tableId, colId);
if (accessCheck.get(colAccess) === 'deny') {
censorAt(colId, idx);
censoredRows.add(idx);
}
}
}
}
if (toRemove.length > 0) {
if (options.allowRowRemoval) {
copyOnNeed();
if (Array.isArray(filteredAction[2])) {
this._removeRowsAt(toRemove, filteredAction[2], filteredAction[3]);
} else {
filteredAction = null;
}
} else {
// Artificially introduced removals are ok, otherwise this is suspect.
if (filteredAction[0] !== 'RemoveRecord' && filteredAction[0] !== 'BulkRemoveRecord') {
throw new Error('Unexpected row removal');
}
}
}
return {filteredAction, censoredRows};
}
// Compute which of the row ids supplied are for rows forbidden for this session.
// If colId is supplied, check instead whether that specific column is forbidden.
private async _getForbiddenRows(cursor: ActionCursor, data: TableDataAction, ids: Set<number>,
colId?: string): Promise<number[]> {
const ruler = await this._getRuler(cursor);
const rec = new RecordView(data, undefined);
const input: AclMatchInput = {user: await this._getUser(cursor.docSession), rec};
const [, tableId, rowIds] = data;
const toRemove: number[] = [];
for (let idx = 0; idx < rowIds.length; idx++) {
rec.index = idx;
if (!ids.has(rowIds[idx])) { continue; }
const rowPermInfo = new PermissionInfo(ruler.ruleCollection, input);
// getTableAccess() evaluates all column rules for THIS record. So it's really rowAccess.
const rowAccess = rowPermInfo.getTableAccess(tableId);
if (!colId) {
if (this.getReadPermission(rowAccess) === 'deny') {
toRemove.push(rowIds[idx]);
}
} else {
const colAccess = rowPermInfo.getColumnAccess(tableId, colId);
if (this.getReadPermission(colAccess) === 'deny') {
toRemove.push(rowIds[idx]);
}
}
}
return toRemove;
}
/**
* Removes the toRemove rows (indexes, not row ids) from the rowIds list and from
* the colValues structure.
*
* toRemove must be sorted, lowest to highest.
*/
private _removeRowsAt(toRemove: number[], rowIds: number[], colValues: BulkColValues|ColValues|undefined) {
if (toRemove.length > 0) {
pruneArray(rowIds, toRemove);
if (colValues) {
for (const values of Object.values(colValues)) {
pruneArray(values, toRemove);
}
}
}
}
/**
* Remove columns from a ColumnValues parameter of certain DocActions, using a predicate for
* which columns to keep.
* Will retain manualSort columns regardless of wildcards.
*/
private _filterColumns(data: BulkColValues|ColValues, shouldInclude: (colId: string) => boolean) {
for (const colId of Object.keys(data)) {
if (colId !== 'manualSort' && !shouldInclude(colId)) {
delete data[colId];
}
}
}
/**
* Get PermissionInfo for the user represented by the given docSession. The returned object
* allows evaluating access level as far as possible without considering specific records.
*
* The result is cached in a WeakMap, and PermissionInfo does its own caching, so multiple calls
* to this._getAccess(docSession).someMethod() will reuse already-evaluated results.
*/
private async _getAccess(docSession: OptDocSession): Promise<PermissionInfo> {
// TODO The intent of caching is to avoid duplicating rule evaluations while processing a
// single request. Caching based on docSession is riskier since those persist across requests.
return this._ruler.getAccess(docSession);
}
private _getUserAttributes(docSession: OptDocSession): UserAttributes {
// TODO Same caching intent and caveat as for _getAccess
return getSetMapValue(this._userAttributesMap as Map<OptDocSession, UserAttributes>, docSession,
() => new UserAttributes());
}
/**
* Check whether user attributes have changed. If so, prompt client
* to reload the document, since we aren't sophisticated enough to
* figure out the changes to send.
*/
private async _checkUserAttributes(docSession: OptDocSession) {
if (!this._prevUserAttributesMap) { return; }
const userAttrBefore = this._prevUserAttributesMap.get(docSession);
if (!userAttrBefore) { return; }
await this._getAccess(docSession); // Makes sure user attrs have actually been computed.
const userAttrAfter = this._getUserAttributes(docSession);
for (const [tableId, rec] of Object.entries(userAttrAfter.rows)) {
const prev = userAttrBefore.rows[tableId];
if (!prev || JSON.stringify(prev.toJSON()) !== JSON.stringify(rec.toJSON())) {
throw new ErrorWithCode('NEED_RELOAD', 'document needs reload, user attributes changed');
}
}
}
/**
* Construct the UserInfo needed for evaluating rules. This also enriches the user with values
* created by user-attribute rules.
*/
private async _getUser(docSession: OptDocSession): Promise<UserInfo> {
const linkParameters = docSession.authorizer?.getLinkParameters() || {};
let access: Role | null;
let fullUser: FullUser | null;
const attrs = this._getUserAttributes(docSession);
access = getDocSessionAccess(docSession);
if (docSession.forkingAsOwner) {
// For granular access purposes, we become an owner.
// It is a bit of a bluff, done on the understanding that this session will
// never be used to edit the document, and that any edits will be done on a
// fork.
access = 'owners';
}
// If aclAsUserId/aclAsUser is set, then override user for acl purposes.
if (linkParameters.aclAsUserId || linkParameters.aclAsUser) {
if (access !== 'owners') { throw new ErrorWithCode('ACL_DENY', 'only an owner can override user'); }
if (attrs.override) {
// Used cached properties.
access = attrs.override.access;
fullUser = attrs.override.user;
} else {
attrs.override = await this._getViewAsUser(linkParameters);
fullUser = attrs.override.user;
}
} else {
fullUser = getDocSessionUser(docSession);
}
const user = new User();
user.Access = access;
const isAnonymous = fullUser?.id === this._homeDbManager?.getAnonymousUserId() ||
fullUser?.id === null;
user.UserID = (!isAnonymous && fullUser?.id) || null;
user.Email = fullUser?.email || null;
user.Name = fullUser?.name || null;
// If viewed from a websocket, collect any link parameters included.
// TODO: could also get this from rest api access, just via a different route.
user.LinkKey = linkParameters;
// Include origin info if accessed via the rest api.
// TODO: could also get this for websocket access, just via a different route.
user.Origin = docSession.req?.get('origin') || null;
user.SessionID = isAnonymous ? `a${getDocSessionAltSessionId(docSession)}` : `u${user.UserID}`;
user.IsLoggedIn = !isAnonymous;
if (this._ruler.ruleCollection.ruleError && !this._recoveryMode) {
// It is important to signal that the doc is in an unexpected state,
// and prevent it opening.
throw this._ruler.ruleCollection.ruleError;
}
for (const clause of this._ruler.ruleCollection.getUserAttributeRules().values()) {
if (clause.name in user) {
log.warn(`User attribute ${clause.name} ignored; conflicts with an existing one`);
continue;
}
if (attrs.rows[clause.name]) {
user[clause.name] = attrs.rows[clause.name];
continue;
}
let rec = new EmptyRecordView();
let rows: TableDataAction|undefined;
try {
// Use lodash's get() that supports paths, e.g. charId of 'a.b' would look up `user.a.b`.
// TODO: add indexes to db.
rows = await this._fetchQueryFromDB({
tableId: clause.tableId,
filters: { [clause.lookupColId]: [get(user, clause.charId)] }
});
} catch (e) {
log.warn(`User attribute ${clause.name} failed`, e);
}
if (rows && rows[2].length > 0) { rec = new RecordView(rows, 0); }
user[clause.name] = rec;
attrs.rows[clause.name] = rec;
}
return user;
}
/**
* Get the "View As" user specified in link parameters.
* If aclAsUserId is set, we get the user with the specified id.
* If aclAsUser is set, we get the user with the specified email,
* from the database if possible, otherwise from user attribute
* tables or examples.
*/
private async _getViewAsUser(linkParameters: Record<string, string>): Promise<UserOverride> {
// Look up user information in database.
if (!this._homeDbManager) { throw new Error('database required'); }
const dbUser = linkParameters.aclAsUserId ?
(await this._homeDbManager.getUser(integerParam(linkParameters.aclAsUserId, 'aclAsUserId'))) :
(await this._homeDbManager.getExistingUserByLogin(linkParameters.aclAsUser));
if (!dbUser && linkParameters.aclAsUser) {
// Look further for the user, in user attribute tables or examples.
const otherUsers = (await this.collectViewAsUsersFromUserAttributeTables())
.concat(this.getExampleViewAsUsers());
const email = normalizeEmail(linkParameters.aclAsUser);
const dummyUser = otherUsers.find(user => normalizeEmail(user?.email || '') === email);
if (dummyUser) {
return {
access: dummyUser.access || null,
user: {
id: -1,
email: dummyUser.email!,
name: dummyUser.name || dummyUser.email!,
}
};
}
}
const docAuth = dbUser && await this._homeDbManager.getDocAuthCached({
urlId: this._docId,
userId: dbUser.id
});
const access = docAuth?.access || null;
const user = dbUser && this._homeDbManager.makeFullUser(dbUser) || null;
return { access, user };
}
/**
* Remove a set of rows from a DocAction. If the DocAction ends up empty, null is returned.
* If the DocAction needs modification, it is copied first - the original is never
* changed.
*/
private _removeRows(a: DocAction, rowIds: Set<number>): DocAction|null {
// If there are no rows, there's nothing to do.
if (isSchemaAction(a)) { return a; }
if (a[0] === 'AddRecord' || a[0] === 'UpdateRecord' || a[0] === 'RemoveRecord') {
return rowIds.has(a[2]) ? null : a;
}
const na = cloneDeep(a);
const [, , oldIds, bulkColValues] = na;
const mask = oldIds.map((id, idx) => rowIds.has(id) ? idx : false).filter(v => v !== false) as number[];
this._removeRowsAt(mask, oldIds, bulkColValues);
if (oldIds.length === 0) { return null; }
return na;
}
/**
* Make a BulkAddRecord for a set of rows.
*/
private _makeAdditions(data: TableDataAction, rowIds: Set<number>): BulkAddRecord|null {
if (rowIds.size === 0) { return null; }
// TODO: optimize implementation, this does an unnecessary clone.
const notAdded = data[2].filter(id => !rowIds.has(id));
const partialData = this._removeRows(data, new Set(notAdded)) as TableDataAction|null;
if (partialData === null) { return partialData; }
return ['BulkAddRecord', partialData[1], partialData[2], partialData[3]];
}
/**
* Make a BulkRemoveRecord for a set of rows.
*/
private _makeRemovals(data: TableDataAction, rowIds: Set<number>): BulkRemoveRecord|null {
if (rowIds.size === 0) { return null; }
return ['BulkRemoveRecord', getTableId(data), [...rowIds]];
}
/**
* Make a BulkUpdateRecord for a particular column across a set of rows.
*/
private _makeColumnUpdate(data: TableDataAction, colId: string, rowIds: Set<number>): BulkUpdateRecord {
const dataRowIds = data[2];
const selectedRowIds = dataRowIds.filter(r => rowIds.has(r));
const colData = data[3][colId].filter((value, idx) => rowIds.has(dataRowIds[idx]));
return ['BulkUpdateRecord', getTableId(data), selectedRowIds, {[colId]: colData}];
}
private async _getSteps(): Promise<Array<ActionStep>> {
if (!this._steps) {
this._steps = this._getUncachedSteps().catch(e => {
log.error('step computation failed:', e);
throw e;
});
}
return this._steps;
}
private async _getMetaSteps(): Promise<Array<MetaStep>> {
if (!this._metaSteps) {
this._metaSteps = this._getUncachedMetaSteps().catch(e => {
log.error('meta step computation failed:', e);
throw e;
});
}
return this._metaSteps;
}
/**
* Prepare to compute intermediate states of rows, as
* this._steps. The computation should happen only if
* needed, which depends on the rules and actions. The computation
* uses the state of the database, and so depends on whether the
* docActions have already been applied to the database or not, as
* determined by the this._applied flag, which should never be
* changed during any possible use of this._steps.
*/
private async _getUncachedSteps(): Promise<Array<ActionStep>> {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const {docActions, undo, applied} = this._activeBundle;
// For row access work, we'll need to know the state of affected rows before and
// after the actions.
// First figure out what rows in which tables are touched during the actions.
const rows = new Map(getRelatedRows(applied ? [...undo].reverse() : docActions));
// Populate a minimal in-memory version of the database with these rows.
const docData = new DocData(
(tableId) => this._fetchQueryFromDB({tableId, filters: {id: [...rows.get(tableId)!]}}),
null,
);
// Load pre-existing rows touched by the bundle.
await Promise.all([...rows.keys()].map(tableId => docData.syncTable(tableId)));
if (applied) {
// Apply the undo actions, since the docActions have already been applied to the db.
for (const docAction of [...undo].reverse()) { docData.receiveAction(docAction); }
}
// Now step forward, storing the before and after state for the table
// involved in each action. We'll use this to compute row access changes.
// For simple changes, the rows will be just the minimal set needed.
// This could definitely be optimized. E.g. for pure table updates, these
// states could be extracted while applying undo actions, with no need for
// a forward pass. And for a series of updates to the same table, there'll
// be duplicated before/after states that could be optimized.
const steps = new Array<ActionStep>();
for (const docAction of docActions) {
const tableId = getTableId(docAction);
const tableData = docData.getTable(tableId);
const rowsBefore = cloneDeep(tableData?.getTableDataAction() || ['TableData', '', [], {}] as TableDataAction);
docData.receiveAction(docAction);
// If table is deleted, state afterwards doesn't matter.
const rowsAfter = docData.getTable(tableId) ?
cloneDeep(tableData?.getTableDataAction() || ['TableData', '', [], {}] as TableDataAction) :
rowsBefore;
const step: ActionStep = {action: docAction, rowsBefore, rowsAfter};
steps.push(step);
}
return steps;
}
/**
* Prepare to compute intermediate metadata and rules, as this._metaSteps.
*/
private async _getUncachedMetaSteps(): Promise<Array<MetaStep>> {
if (!this._activeBundle) { throw new Error('no active bundle'); }
const {docActions, undo, applied} = this._activeBundle;
const needMeta = docActions.some(a => isSchemaAction(a) || getTableId(a).startsWith('_grist_'));
if (!needMeta) {
// Sometimes, the intermediate states are trivial.
return docActions.map(action => ({action}));
}
const metaDocData = new DocData(
async (tableId) => {
const result = this._docData.getTable(tableId)?.getTableDataAction();
if (!result) { throw new Error('surprising load'); }
return result;
},
null,
);
// Read the structural tables.
await Promise.all([...STRUCTURAL_TABLES].map(tableId => metaDocData.syncTable(tableId)));
if (applied) {
for (const docAction of [...undo].reverse()) { metaDocData.receiveAction(docAction); }
}
let meta = {} as {[key: string]: TableDataAction};
// Metadata is stored as a hash of TableDataActions.
for (const tableId of STRUCTURAL_TABLES) {
meta[tableId] = cloneDeep(metaDocData.getTable(tableId)!.getTableDataAction());
}
// Now step forward, tracking metadata and rules through any changes that occur.
const steps = new Array<MetaStep>();
let ruler = this._ruler;
if (applied) {
// Rules may have changed - back them off to a copy of their original state.
ruler = new Ruler(this);
await ruler.update(metaDocData);
}
let replaceRuler = false;
for (const docAction of docActions) {
const tableId = getTableId(docAction);
const step: MetaStep = {action: docAction};
step.metaBefore = meta;
if (STRUCTURAL_TABLES.has(tableId)) {
metaDocData.receiveAction(docAction);
// make shallow copy of all tables
meta = {...meta};
// replace table just modified with a deep copy
meta[tableId] = cloneDeep(metaDocData.getTable(tableId)!.getTableDataAction());
}
step.metaAfter = meta;
// replaceRuler logic avoids updating rules between paired changes of resources and rules.
if (actionHasRuleChange(docAction)) {
replaceRuler = true;
} else if (replaceRuler) {
ruler = new Ruler(this);
await ruler.update(metaDocData);
replaceRuler = false;
}
step.ruler = ruler;
steps.push(step);
}
return steps;
}
/**
* Return any permitted parts of an action. A completely forbidden
* action results in an empty list. Forbidden columns and rows will
* be stripped from a returned action. Rows with forbidden cells are
* extracted and returned in distinct actions (since they will have
* a distinct set of columns).
*
* This method should only be called with data actions, and will throw
* for anything else.
*/
private async _prefilterDocAction(cursor: ActionCursor): Promise<DocAction[]> {
const {action, docSession} = cursor;
const tableId = getTableId(action);
const permInfo = await this._getStepAccess(cursor);
const tableAccess = permInfo.getTableAccess(tableId);
const accessCheck = await this._getAccessForActionType(docSession, action, 'check');
const access = accessCheck.get(tableAccess);
if (access === 'deny') {
// Filter out this action entirely.
return [];
} else if (access === 'allow') {
// Retain this action entirely.
return [action];
} else if (access === 'mixedColumns') {
// Retain some or all columns entirely.
const act = this._pruneColumns(action, permInfo, tableId, accessCheck);
return act ? [act] : [];
}
// The remainder is the mixed condition.
const {rowsBefore, rowsAfter} = await this._getRowsForRecAndNewRec(cursor);
const {censoredRows, filteredAction} = await this._filterRowsAndCells({...cursor, action: cloneDeep(action)},
rowsBefore, rowsAfter, accessCheck,
{allowRowRemoval: true});
if (filteredAction === null) {
return [];
}
if (!isDataAction(filteredAction)) {
throw new Error('_prefilterDocAction called with unexpected action');
}
if (isRemoveRecordAction(filteredAction)) {
// removals do not mention columns or cells, so no further complications.
return [filteredAction];
}
// Strip any forbidden columns.
this._filterColumns(
filteredAction[3],
(colId) => accessCheck.get(permInfo.getColumnAccess(tableId, colId)) !== 'deny');
if (censoredRows.size === 0) {
// no cell censorship, so no further complications.
return [filteredAction];
}
return filterColValues(filteredAction, (idx) => censoredRows.has(idx), gristTypes.isCensored);
}
/**
* Tailor the information about a change reported to a given client. The action passed in
* is never modified. The actions output may differ in the following ways:
* - Tables, columns or rows may be omitted if the client does not have access to them.
* - Columns in structural metadata tables may be cleared if the client does not have
* access to the resources they relate to.
* - Columns in the _grist_Views table may be cleared or uncleared depending on changes
* in other metadata tables.
* - Rows may be inserted if the client newly acquires access to them via an update.
* TODO: I think that column rules controlling READ access using rec are not fully supported
* yet. They work on first load, but if READ access is lost/gained updates won't be made.
*/
private async _filterOutgoingDocAction(cursor: ActionCursor): Promise<DocAction[]> {
const {action} = cursor;
const tableId = getTableId(action);
const permInfo = await this._getStepAccess(cursor);
const tableAccess = permInfo.getTableAccess(tableId);
const access = this.getReadPermission(tableAccess);
const readAccessCheck = this._readAccessCheck(cursor.docSession);
const results: DocAction[] = [];
if (access === 'deny') {
// filter out this data.
} else if (access === 'allow') {
results.push(action);
} else if (access === 'mixedColumns') {
const act = this._pruneColumns(action, permInfo, tableId, readAccessCheck);
if (act) { results.push(act); }
} else {
// The remainder is the mixed condition.
for (const act of await this._pruneRows(cursor)) {
const prunedAct = this._pruneColumns(act, permInfo, tableId, readAccessCheck);
if (prunedAct) { results.push(prunedAct); }
}
}
const secondPass: DocAction[] = [];
for (const act of results) {
if (STRUCTURAL_TABLES.has(getTableId(act)) && isDataAction(act)) {
await this._filterOutgoingStructuralTables(cursor, act, secondPass);
} else {
secondPass.push(act);
}
}
return secondPass;
}
private async _filterOutgoingStructuralTables(cursor: ActionCursor, act: DataAction, results: DocAction[]) {
// Filter out sensitive columns from tables.
const permissionInfo = await this._getStepAccess(cursor);
const step = await this._getMetaStep(cursor);
if (!step.metaAfter) { throw new Error('missing metadata'); }
act = cloneDeep(act); // Don't change original action.
const ruler = await this._getRuler(cursor);
const censor = new CensorshipInfo(permissionInfo,
ruler.ruleCollection,
step.metaAfter,
await this.hasAccessRulesPermission(cursor.docSession));
if (censor.apply(act)) {
results.push(act);
}
// There's a wrinkle to deal with. If we just added or removed a section, we need to
// reconsider whether the view containing it is visible.
if (getTableId(act) === '_grist_Views_section') {
if (!step.metaBefore) { throw new Error('missing prior metadata'); }
const censorBefore = new CensorshipInfo(permissionInfo,
ruler.ruleCollection,
step.metaBefore,
await this.hasAccessRulesPermission(cursor.docSession));
// For all views previously censored, if they are now uncensored,
// add an UpdateRecord to expose them.
for (const v of censorBefore.censoredViews) {
if (!censor.censoredViews.has(v)) {
const table = step.metaAfter._grist_Views;
const idx = table[2].indexOf(v);
const name = table[3].name[idx];
results.push(['UpdateRecord', '_grist_Views', v, {name}]);
}
}
// For all views currently censored, if they were previously uncensored,
// add an UpdateRecord to censor them.
for (const v of censor.censoredViews) {
if (!censorBefore.censoredViews.has(v)) {
results.push(['UpdateRecord', '_grist_Views', v, {name: ''}]);
}
}
}
}
private async _checkIncomingDocAction(cursor: ActionCursor): Promise<void> {
const {action, docSession} = cursor;
const accessCheck = await this._getAccessForActionType(docSession, action, 'fatal');
const tableId = getTableId(action);
const permInfo = await this._getStepAccess(cursor);
const tableAccess = permInfo.getTableAccess(tableId);
const access = accessCheck.get(tableAccess);
if (access === 'allow') { return; }
if (access === 'mixed') {
// Deal with row-level access for the mixed condition.
await this._checkRows(cursor, accessCheck);
}
// Somewhat abusing prune method by calling it with an access function that
// throws on denial.
this._pruneColumns(action, permInfo, tableId, accessCheck);
}
private async _getRuler(cursor: ActionCursor) {
if (cursor.actionIdx === null) { return this._ruler; }
const step = await this._getMetaStep(cursor);
return step.ruler || this._ruler;
}
private async _getStepAccess(cursor: ActionCursor) {
if (!this._activeBundle) { throw new Error('no active bundle'); }
if (this._activeBundle.hasAnyRuleChange) {
const step = await this._getMetaStep(cursor);
if (step.ruler) { return step.ruler.getAccess(cursor.docSession); }
}
// No rule changes!
return this._getAccess(cursor.docSession);
}
private async _getStep(cursor: ActionCursor) {
if (cursor.actionIdx === null) { throw new Error('No step available'); }
const steps = await this._getSteps();
return steps[cursor.actionIdx];
}
private async _getMetaStep(cursor: ActionCursor) {
if (cursor.actionIdx === null) { throw new Error('No step available'); }
const steps = await this._getMetaSteps();
return steps[cursor.actionIdx];
}
// Get an AccessCheck appropriate for the specific action.
// TODO: deal with ReplaceTableData, which both deletes and creates rows.
private async _getAccessForActionType(docSession: OptDocSession, a: DocAction,
severity: 'check'|'fatal'): Promise<IAccessCheck> {
if (this._hasExceptionalFullAccess(docSession)) {
return dummyAccessCheck;
}
const tableId = getTableId(a);
if (tableId.startsWith('_grist') && tableId !== '_grist_Attachments') {
// Actions on any metadata table currently require the schemaEdit flag.
// Exception: the attachments table, which needs to be reworked to be compatible
// with granular access.
// Another exception: ensure owners always have full access to ACL tables, so they
// can change rules and don't get stuck.
if (isAclTable(tableId) && await this.isOwner(docSession)) {
return dummyAccessCheck;
}
return accessChecks[severity].schemaEdit;
} else if (a[0] === 'UpdateRecord' || a[0] === 'BulkUpdateRecord') {
return accessChecks[severity].update;
} else if (a[0] === 'RemoveRecord' || a[0] === 'BulkRemoveRecord') {
return accessChecks[severity].delete;
} else if (a[0] === 'AddRecord' || a[0] === 'BulkAddRecord') {
return accessChecks[severity].create;
} else {
return accessChecks[severity].schemaEdit;
}
}
}
/**
* A snapshots of rules and permissions at during one of more steps within a bundle.
*/
export class Ruler {
// The collection of all rules, with helpful accessors.
public ruleCollection = new ACLRuleCollection();
// Cache of PermissionInfo associated with the given docSession. It's a WeakMap, so should allow
// both to be garbage-collected once docSession is no longer in use.
private _permissionInfoMap = new WeakMap<OptDocSession, Promise<PermissionInfo>>();
public constructor(private _owner: RulerOwner) {}
public async getAccess(docSession: OptDocSession): Promise<PermissionInfo> {
// TODO The intent of caching is to avoid duplicating rule evaluations while processing a
// single request. Caching based on docSession is riskier since those persist across requests.
return getSetMapValue(this._permissionInfoMap as Map<OptDocSession, Promise<PermissionInfo>>, docSession,
async () => new PermissionInfo(this.ruleCollection, {user: await this._owner.getUser(docSession)}));
}
public flushAccess(docSession: OptDocSession) {
this._permissionInfoMap.delete(docSession);
}
/**
* Update granular access from DocData.
*/
public async update(docData: DocData) {
await this.ruleCollection.update(docData, {log, compile: compileAclFormula, includeHelperCols: true});
// Also clear the per-docSession cache of rule evaluations.
this.clearCache();
}
public clearCache() {
this._permissionInfoMap = new WeakMap();
}
public haveRules() {
return this.ruleCollection.haveRules();
}
}
export interface RulerOwner {
getUser(docSession: OptDocSession): Promise<UserInfo>;
}
/**
* Information about a single step within a bundle. We cache this information to share
* when filtering output to several clients.
*/
export interface ActionStep {
action: DocAction;
rowsBefore: TableDataAction|undefined; // only defined for actions modifying rows
rowsAfter: TableDataAction|undefined; // only defined for actions modifying rows
rowsLast?: TableDataAction; // cached calculation of where to point "newRec"
}
export interface MetaStep {
action: DocAction;
metaBefore?: {[key: string]: TableDataAction}; // cached structural metadata before action
metaAfter?: {[key: string]: TableDataAction}; // cached structural metadata after action
ruler?: Ruler; // rules at this step
}
/**
* A pointer to a particular step within a bundle for a particular session.
*/
interface ActionCursor {
action: DocAction;
docSession: OptDocSession;
actionIdx: number|null;
}
/**
* A row-like view of TableDataAction, which is columnar in nature. If index value
* is undefined, acts as an EmptyRecordRow.
*/
export class RecordView implements InfoView {
public constructor(public data: TableDataAction, public index: number|undefined) {
}
public get(colId: string): CellValue {
if (this.index === undefined) { return null; }
if (colId === 'id') {
return this.data[2][this.index];
}
return this.data[3][colId]?.[this.index];
}
public has(colId: string) {
return colId === 'id' || colId in this.data[3];
}
public toJSON() {
if (this.index === undefined) { return {}; }
const results: {[key: string]: any} = {};
for (const key of Object.keys(this.data[3])) {
results[key] = this.data[3][key]?.[this.index];
}
return results;
}
}
/**
* A read-write view of a DataAction, for use in censorship.
*/
class RecordEditor implements InfoEditor {
private _rows: number[];
private _bulk: boolean;
private _data: ColValues | BulkColValues;
public constructor(public data: DataAction, public index: number|undefined,
public optional: boolean) {
const rows = data[2];
this._bulk = Array.isArray(rows);
this._rows = Array.isArray(rows) ? rows : [rows];
this._data = data[3] || {};
}
public get(colId: string): CellValue {
if (this.index === undefined) { return null; }
if (colId === 'id') {
return this._rows[this.index];
}
return this._bulk ?
(this._data as BulkColValues)[colId][this.index] :
(this._data as ColValues)[colId];
}
public set(colId: string, val: CellValue): this {
if (this.index === undefined) { throw new Error('cannot set value of non-existent cell'); }
if (colId === 'id') { throw new Error('cannot change id'); }
if (this.optional && !(colId in this._data)) { return this; }
if (this._bulk) {
(this._data as BulkColValues)[colId][this.index] = val;
} else {
(this._data as ColValues)[colId] = val;
}
return this;
}
public toJSON() {
if (this.index === undefined) { return {}; }
const results: {[key: string]: any} = {};
for (const key of Object.keys(this._data)) {
results[key] = this.get(key);
}
return results;
}
}
class EmptyRecordView implements InfoView {
public get(colId: string): CellValue { return null; }
public toJSON() { return {}; }
}
/**
* Cache information about user attributes.
*/
class UserAttributes {
public rows: {[clauseName: string]: InfoView} = {};
public override?: UserOverride;
}
interface IAccessCheck {
get(ps: PermissionSetWithContext): string;
throwIfDenied(ps: PermissionSetWithContext): void;
throwIfNotFullyAllowed(ps: PermissionSetWithContext): void;
}
class AccessCheck implements IAccessCheck {
constructor(public access: 'update'|'delete'|'create'|'schemaEdit'|'read',
public severity: 'check'|'fatal') {
}
public get(ps: PermissionSetWithContext): string {
const result = ps.perms[this.access];
if (result !== 'deny' || this.severity !== 'fatal') { return result; }
this.throwIfDenied(ps);
return result;
}
public throwIfDenied(ps: PermissionSetWithContext): void {
const result = ps.perms[this.access];
if (result !== 'deny') { return; }
this._throwError(ps);
}
public throwIfNotFullyAllowed(ps: PermissionSetWithContext): void {
const result = ps.perms[this.access];
if (result === 'allow') { return; }
this._throwError(ps);
}
private _throwError(ps: PermissionSetWithContext): void {
const memos = ps.getMemos()[this.access];
const label =
this.access === 'schemaEdit' ? 'structure' :
this.access;
throw new ErrorWithCode('ACL_DENY', `Blocked by ${ps.ruleType} ${label} access rules`, {
memos,
status: 403
});
}
}
export const accessChecks = {
check: fromPairs(ALL_PERMISSION_PROPS.map(prop => [prop, new AccessCheck(prop, 'check')])),
fatal: fromPairs(ALL_PERMISSION_PROPS.map(prop => [prop, new AccessCheck(prop, 'fatal')])),
};
// This AccessCheck allows everything.
const dummyAccessCheck: IAccessCheck = {
get() { return 'allow'; },
throwIfDenied() {},
throwIfNotFullyAllowed() {}
};
/**
* Manage censoring metadata.
*
* For most metadata, censoring means blanking out certain fields, rather than removing rows,
* (because the latter was too big of a change). In particular, these changes are relied on by
* other code:
*
* - Censored tables (from _grist_Tables) have cleared tableId field. To check for it, use the
* isTableCensored() helper in app/common/isHiddenTable.ts. This is used by exports to Excel.
*/
export class CensorshipInfo {
public censoredTables = new Set<number>();
public censoredSections = new Set<number>();
public censoredViews = new Set<number>();
public censoredColumns = new Set<number>();
public censoredFields = new Set<number>();
public censored = {
_grist_Tables: this.censoredTables,
_grist_Tables_column: this.censoredColumns,
_grist_Views: this.censoredViews,
_grist_Views_section: this.censoredSections,
_grist_Views_section_field: this.censoredFields,
};
public constructor(permInfo: PermissionInfo,
ruleCollection: ACLRuleCollection,
tables: {[key: string]: TableDataAction},
private _canViewACLs: boolean) {
// Collect a list of censored columns (by "<tableRef> <colId>").
const columnCode = (tableRef: number, colId: string) => `${tableRef} ${colId}`;
const censoredColumnCodes: Set<string> = new Set();
const tableRefToTableId: Map<number, string> = new Map();
const tableRefToIndex: Map<number, number> = new Map();
const uncensoredTables: Set<number> = new Set();
// Scan for forbidden tables.
let rec = new RecordView(tables._grist_Tables, undefined);
let ids = getRowIdsFromDocAction(tables._grist_Tables);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
const tableId = rec.get('tableId') as string;
const tableRef = ids[idx];
tableRefToTableId.set(tableRef, tableId);
tableRefToIndex.set(tableRef, idx);
const tableAccess = permInfo.getTableAccess(tableId);
if (tableAccess.perms.read === 'deny') {
this.censoredTables.add(tableRef);
} else if (tableAccess.perms.read === 'allow') {
uncensoredTables.add(tableRef);
}
}
// Scan for forbidden columns.
ids = getRowIdsFromDocAction(tables._grist_Tables_column);
rec = new RecordView(tables._grist_Tables_column, undefined);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
const tableRef = rec.get('parentId') as number;
if (uncensoredTables.has(tableRef)) { continue; }
const tableId = tableRefToTableId.get(tableRef);
if (!tableId) { throw new Error('table not found'); }
const colId = rec.get('colId') as string;
if (this.censoredTables.has(tableRef) ||
(colId !== 'manualSort' && permInfo.getColumnAccess(tableId, colId).perms.read === 'deny')) {
censoredColumnCodes.add(columnCode(tableRef, colId));
}
}
// Collect a list of all sections and views containing a table to which the user has no access.
rec = new RecordView(tables._grist_Views_section, undefined);
ids = getRowIdsFromDocAction(tables._grist_Views_section);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
if (!this.censoredTables.has(rec.get('tableRef') as number)) { continue; }
const parentId = rec.get('parentId') as number;
if (parentId) { this.censoredViews.add(parentId); }
this.censoredSections.add(ids[idx]);
}
// Collect a list of all columns from tables to which the user has no access.
rec = new RecordView(tables._grist_Tables_column, undefined);
ids = getRowIdsFromDocAction(tables._grist_Tables_column);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
const parentId = rec.get('parentId') as number;
if (this.censoredTables.has(parentId) ||
censoredColumnCodes.has(columnCode(parentId, rec.get('colId') as string))) {
this.censoredColumns.add(ids[idx]);
}
}
// Collect a list of all fields from sections to which the user has no access.
rec = new RecordView(tables._grist_Views_section_field, undefined);
ids = getRowIdsFromDocAction(tables._grist_Views_section_field);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
if (!this.censoredSections.has(rec.get('parentId') as number) &&
!this.censoredColumns.has(rec.get('colRef') as number)) { continue; }
this.censoredFields.add(ids[idx]);
}
// Now undo some of the above...
// Specifically, when a summary table is not censored, uncensor the source table's raw view section,
// so that the user can see the source table's title,
// which is used to construct the summary table's title. The section's fields remain censored.
// This would also be a sensible place to uncensor the source tableId, but that causes other problems.
rec = new RecordView(tables._grist_Tables, undefined);
ids = getRowIdsFromDocAction(tables._grist_Tables);
for (let idx = 0; idx < ids.length; idx++) {
rec.index = idx;
const tableRef = ids[idx];
const sourceTableRef = rec.get('summarySourceTable') as number;
const sourceTableIndex = tableRefToIndex.get(sourceTableRef);
if (
this.censoredTables.has(tableRef) ||
!sourceTableRef ||
sourceTableIndex === undefined ||
!this.censoredTables.has(sourceTableRef)
) { continue; }
rec.index = sourceTableIndex;
const rawViewSectionRef = rec.get('rawViewSectionRef') as number;
this.censoredSections.delete(rawViewSectionRef);
}
}
public apply(a: DataAction) {
const tableId = getTableId(a);
const ids = getRowIdsFromDocAction(a);
if (!STRUCTURAL_TABLES.has(tableId)) { return true; }
if (!(tableId in this.censored)) {
if (!this._canViewACLs && a[0] === 'TableData') {
a[2] = [];
a[3] = {};
}
return this._canViewACLs;
}
const rec = new RecordEditor(a, undefined, true);
const method = getCensorMethod(getTableId(a));
const censoredRows = (this.censored as any)[tableId] as Set<number>;
for (const [index, id] of ids.entries()) {
if (censoredRows.has(id)) {
rec.index = index;
method(rec);
}
}
return true;
}
}
function getCensorMethod(tableId: string): (rec: RecordEditor) => void {
switch (tableId) {
case '_grist_Tables':
return rec => rec.set('tableId', '');
case '_grist_Views':
return rec => rec.set('name', '');
case '_grist_Views_section':
return rec => rec.set('title', '').set('tableRef', 0);
case '_grist_Tables_column':
return rec => rec.set('label', '').set('colId', '').set('widgetOptions', '')
.set('formula', '').set('type', 'Any').set('parentId', 0);
case '_grist_Views_section_field':
return rec => rec.set('widgetOptions', '').set('filter', '').set('parentId', 0);
case '_grist_ACLResources':
return rec => rec;
case '_grist_ACLRules':
return rec => rec;
default:
throw new Error(`cannot censor ${tableId}`);
}
}
function scanActionsRecursively<T extends DocAction|UserAction>(actions: T[],
check: (action: T) => boolean): boolean {
for (const a of actions) {
if (a[0] === 'ApplyUndoActions' || a[0] === 'ApplyDocActions') {
return scanActionsRecursively(a[1] as T[], check);
}
if (check(a)) { return true; }
}
return false;
}
async function applyToActionsRecursively(actions: (DocAction|UserAction)[],
op: (action: DocAction|UserAction) => Promise<void>): Promise<void> {
for (const a of actions) {
if (a[0] === 'ApplyUndoActions' || a[0] === 'ApplyDocActions') {
await applyToActionsRecursively(a[1] as UserAction[], op);
}
await op(a);
}
}
/**
* Takes an action, and removes certain cells from it. The action
* passed in is modified in place, and also returned as part of a list
* of derived actions.
*
* For a non-bulk action, any cell values that return true for
* shouldFilterCell are removed. For a bulk action, there's no way to
* express that in general in a single action. For a bulk action, for
* any row (identified by row index, not rowId) that returns true for
* shouldFilterRow, we remove cell values based on shouldFilterCell
* and add the row to an action with just the remaining cell values.
*
* This is by no means a general-purpose function. It is used only in
* the implementation of partial undos. If is factored out for
* testing purposes.
*
* This method could be made unnecessary if a way were created to have
* unambiguous "holes" in column value arrays, where values for some
* rows are omitted.
*/
export function filterColValues(action: DataAction,
shouldFilterRow: (idx: number) => boolean,
shouldFilterCell: (value: CellValue) => boolean): DataAction[] {
if (isRemoveRecordAction(action)) {
// removals do not have cells, so nothing to do.
return [action];
}
const colIds = Object.keys(action[3]).sort();
const colValues = action[3];
if (!isBulkAction(action)) {
for (const colId of colIds) {
if (shouldFilterCell((colValues as ColValues)[colId])) {
delete colValues[colId];
}
}
return [action];
}
const rowIds = action[2];
// For bulk operations, censored cells require us to reorganize into a set of actions
// with different columns.
const parts: Map<string, typeof action> = new Map();
let at = 0;
for (let idx = 0; idx < rowIds.length; idx++) {
if (!shouldFilterRow(idx)) {
if (idx !== at) {
// Shuffle columnar data up as we remove rows.
rowIds[at] = rowIds[idx];
for (const colId of colIds) {
(colValues as BulkColValues)[colId][at] = (colValues as BulkColValues)[colId][idx];
}
}
at++;
continue;
}
// Some censored data in this row, so move the row to an action specialized
// for the set of columns this row has.
const keys: string[] = [];
const values: BulkColValues = {};
for (const colId of colIds) {
const value = (colValues as BulkColValues)[colId][idx];
if (!shouldFilterCell(value)) {
values[colId] = [value];
keys.push(colId);
}
}
const mergedKey = keys.join(' ');
const peers = parts.get(mergedKey);
if (!peers) {
parts.set(mergedKey, [action[0], action[1], [rowIds[idx]], values]);
} else {
peers[2].push(rowIds[idx]);
for (const key of keys) {
peers[3][key].push(values[key][0]);
}
}
}
// Truncate columnar data.
rowIds.length = at;
for (const colId of colIds) {
(colValues as BulkColValues)[colId].length = at;
}
// Return all actions, in a consistent order for test purposes.
return [action, ...[...parts.keys()].sort().map(key => parts.get(key)!)];
}
/**
* Information about a user, including any user attributes.
*
* Serializes into a more compact JSON form that excludes full
* row data, only keeping user info and table/row ids for any
* user attributes.
*
* See `user.py` for the sandbox equivalent that deserializes objects of this class.
*/
export class User implements UserInfo {
public Name: string | null = null;
public UserID: number | null = null;
public Access: Role | null = null;
public Origin: string | null = null;
public LinkKey: Record<string, string | undefined> = {};
public Email: string | null = null;
[attribute: string]: any;
constructor(_info: Record<string, unknown> = {}) {
Object.assign(this, _info);
}
public toJSON() {
const results: {[key: string]: any} = {};
for (const [key, value] of Object.entries(this)) {
if (value instanceof RecordView) {
// Only include the table id and first matching row id.
results[key] = [getTableId(value.data), value.get('id')];
} else if (value instanceof EmptyRecordView) {
results[key] = null;
} else {
results[key] = value;
}
}
return results;
}
}
export function validTableIdString(tableId: any): string {
if (typeof tableId !== 'string') { throw new Error(`Expected tableId to be a string`); }
return tableId;
}
function actionHasRuleChange(a: DocAction): boolean {
return isAclTable(getTableId(a)) || (
// Check if any helper columns have been specified while adding/updating a metadata record,
// as this will affect the result of `getHelperCols` in `ACLRuleCollection.ts` and thus the set of ACL resources.
// Note that removing a helper column doesn't directly trigger this code, but:
// - It will typically be accompanied closely by unsetting the helper column on the metadata record.
// - `getHelperCols` can handle non-existent helper columns and other similarly invalid metadata.
// - Since the column is removed, ACL restrictions on it don't really matter.
isDataAction(a)
&& ["_grist_Tables_column", "_grist_Views_section_field"].includes(getTableId(a))
&& Boolean(
a[3]?.hasOwnProperty('rules') ||
a[3]?.hasOwnProperty('displayCol')
)
);
}