gristlabs_grist-core/app/server/lib/GranularAccess.ts
Paul Fitzpatrick 438f259687 (core) start reconciling forking with granular access
Summary:
This allows a fork to be made by a user if:
 * That user is an owner of the document being forked, or
 * That user has full read access to the document being forked.

The bulk of the diff is reorganization of how forking is done.  ActiveDoc.fork is now responsible for creating a fork, not just a docId/urlId for the fork. Since fork creation should not be limited to the doc worker hosting the trunk, a helper endpoint is added for placing the fork.

The change required sanitizing worker allocation a bit, and allowed session knowledge to be removed from HostedStorageManager.

Test Plan: Added test; existing tests pass.

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2700
2021-01-12 14:08:49 -05:00

1150 lines
50 KiB
TypeScript

import { MixedPermissionSet, PartialPermissionSet, PermissionSet, TablePermissionSet } from 'app/common/ACLPermissions';
import { makePartialPermissions, mergePartialPermissions, mergePermissions } from 'app/common/ACLPermissions';
import { emptyPermissionSet, toMixed } from 'app/common/ACLPermissions';
import { ACLRuleCollection } from 'app/common/ACLRuleCollection';
import { ActionGroup } from 'app/common/ActionGroup';
import { createEmptyActionSummary } from 'app/common/ActionSummary';
import { Query } from 'app/common/ActiveDocAPI';
import { ApiError } from 'app/common/ApiError';
import { AsyncCreate } from 'app/common/AsyncCreate';
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 { ErrorWithCode } from 'app/common/ErrorWithCode';
import { AclMatchInput, InfoView } from 'app/common/GranularAccessClause';
import { RuleSet, UserInfo } from 'app/common/GranularAccessClause';
import { getSetMapValue, isObject } from 'app/common/gutil';
import { canView } from 'app/common/roles';
import { compileAclFormula } from 'app/server/lib/ACLFormula';
import { getDocSessionAccess, getDocSessionUser, OptDocSession } from 'app/server/lib/DocSession';
import * as log from 'app/server/lib/log';
import { getRelatedRows, getRowIdsFromDocAction } from 'app/server/lib/RowAccess';
import cloneDeep = require('lodash/cloneDeep');
import get = require('lodash/get');
import pullAt = require('lodash/pullAt');
// tslint:disable:no-bitwise
// Actions that may be allowed for a user with nuanced access to a document, depending
// on what table they refer to.
const ACTION_WITH_TABLE_ID = new Set(['AddRecord', 'BulkAddRecord', 'UpdateRecord', 'BulkUpdateRecord',
'RemoveRecord', 'BulkRemoveRecord',
'ReplaceTableData', 'TableData',
]);
// Check if action has a tableId.
function isTableAction(a: UserAction): a is AddRecord | BulkAddRecord | UpdateRecord | BulkUpdateRecord |
RemoveRecord | BulkRemoveRecord | ReplaceTableData | TableDataAction {
return ACTION_WITH_TABLE_ID.has(String(a[0]));
}
// Actions that won't be allowed (yet) for a user with nuanced access to a document.
// A few may be innocuous, but generally I've put them in this list if there are problems
// tracking down what table the refer to, or they could allow creation/modification of a
// formula.
const SPECIAL_ACTIONS = new Set(['InitNewDoc',
'EvalCode',
'SetDisplayFormula',
'CreateViewSection',
'UpdateSummaryViewSection',
'DetachSummaryViewSection',
'GenImporterView',
'TransformAndFinishImport',
'AddColumn', 'RemoveColumn', 'RenameColumn', 'ModifyColumn',
'AddTable', 'RemoveTable', 'RenameTable',
'AddView',
'CopyFromColumn',
'AddHiddenColumn',
'RemoveViewSection'
]);
// 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', 'AddEmptyTable']);
/**
*
* 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:
*
* - canMaybeApplyUserActions(), 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.
* - canApplyDocActions(), 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.
* - appliedActions(), called when DocActions have been applied to the DB, but before
* those changes have been sent to clients.
* - filterActionGroup() and filterOutgoingDocActions() are called for each client.
* - finishedActions(), called when completely done with modification and any needed
* client notifications, whether successful or failed.
*
*/
export class GranularAccess {
// The collection of all rules, with helpful accessors.
private _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>>();
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 _rowSnapshots: AsyncCreate<Array<[TableDataAction, TableDataAction]>>|null = null;
// Flag tracking whether a set of actions have been applied to the database or not.
private _applied: boolean = false;
public constructor(
private _docData: DocData,
private _fetchQueryFromDB: (query: Query) => Promise<TableDataAction>,
private _recoveryMode: boolean) {
}
/**
* Update granular access from DocData.
*/
public async update() {
await this._ruleCollection.update(this._docData, {log, compile: compileAclFormula});
// Also clear the per-docSession cache of rule evaluations and user attributes.
this._permissionInfoMap = new WeakMap();
this._userAttributesMap = new WeakMap();
}
/**
* Check whether user can carry out query.
*/
public hasQueryAccess(docSession: OptDocSession, query: Query) {
return this.hasTableAccess(docSession, query.tableId);
}
/**
* Check whether user has any access to table.
*/
public async hasTableAccess(docSession: OptDocSession, tableId: string) {
const pset = await this.getTableAccess(docSession, tableId);
return pset.read !== 'deny';
}
/**
* 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 canApplyDocActions(docSession: OptDocSession, docActions: DocAction[], undo: DocAction[]) {
this._applied = false;
if (this._ruleCollection.haveRules()) {
this._prepareRowSnapshots(docActions, undo);
await Promise.all(
docActions.map((action, idx) => this._checkIncomingDocAction(docSession, action, idx)));
}
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.
if (docActions.some(docAction => ['_grist_ACLRules', '_grist_ACLResources'].includes(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.getTable('_grist_Tables')!.getTableDataAction(),
_grist_Tables_column: this._docData.getTable('_grist_Tables_column')!.getTableDataAction(),
_grist_ACLResources: this._docData.getTable('_grist_ACLResources')!.getTableDataAction(),
_grist_ACLRules: this._docData.getTable('_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 appliedActions(docActions: DocAction[], undo: DocAction[]) {
this._applied = true;
// 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 => getTableId(docAction) === '_grist_ACLRules' ||
getTableId(docAction) === '_grist_Resources')) {
await this.update();
return;
}
if (!this._ruleCollection.haveRules()) { return; }
// If there is a schema change, redo from scratch for now.
// TODO: this is placeholder code. Should deal with connected clients.
if (docActions.some(docAction => isSchemaAction(docAction))) {
await this.update();
return;
}
// Check if a table that affects user attributes has changed. If so, put current
// attributes aside for later comparison, and clear caches.
const attrs = new Set([...this._ruleCollection.getUserAttributeRules().values()].map(r => r.tableId));
if (docActions.some(docAction => attrs.has(getTableId(docAction)))) {
this._prevUserAttributesMap = this._userAttributesMap;
this._permissionInfoMap = new WeakMap();
this._userAttributesMap = new WeakMap();
return;
}
}
/**
* This should be called once an action bundle has been broadcast to all clients.
* It will clean up any temporary state cached for filtering those broadcasts.
*/
public async finishedActions() {
this._applied = false;
if (this._rowSnapshots) { this._rowSnapshots.clear(); }
this._rowSnapshots = null;
this._prevUserAttributesMap = undefined;
}
/**
* Filter DocActions to be sent to a client.
*/
public async filterOutgoingDocActions(docSession: OptDocSession, docActions: DocAction[]): Promise<DocAction[]> {
await this._checkUserAttributes(docSession);
const actions = await Promise.all(
docActions.map((action, idx) => this._pruneOutgoingDocAction(docSession, action, idx)));
return ([] as DocAction[]).concat(...actions);
}
/**
* Filter an ActionGroup to be sent to a client.
*/
public async filterActionGroup(docSession: OptDocSession, actionGroup: ActionGroup): Promise<ActionGroup> {
if (await this.allowActionGroup(docSession, actionGroup)) { return actionGroup; }
// For now, if there's any nuance at all, suppress the summary and description.
// TODO: create an empty action summary, to be sure not to leak anything important.
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 acceptible parts of ActionGroup, rather than denying entirely.
*/
public async allowActionGroup(docSession: OptDocSession, actionGroup: ActionGroup): Promise<boolean> {
return this.canReadEverything(docSession);
}
/**
* Check if user may be able to apply a list of actions. If it fails, the user cannot
* apply the actions. If it succeeds, the actions will need examination in more detail.
* TODO: not smart about intermediate states, if there is a table or column rename it will
* have trouble, and might forbid something that should be allowed.
*/
public async canMaybeApplyUserActions(docSession: OptDocSession, actions: UserAction[]): Promise<boolean> {
for (const action of actions) {
if (!await this.canMaybeApplyUserAction(docSession, action)) { return false; }
}
return true;
}
/**
* Check if user can apply a given action to the document.
*/
public async canMaybeApplyUserAction(docSession: OptDocSession, a: UserAction|DocAction): Promise<boolean> {
const name = a[0] as string;
if (OK_ACTIONS.has(name)) { return true; }
if (SPECIAL_ACTIONS.has(name)) {
return !this.hasNuancedAccess(docSession);
}
if (SURPRISING_ACTIONS.has(name)) {
return this.hasFullAccess(docSession);
}
if (a[0] === 'ApplyUndoActions') {
return this.canMaybeApplyUserActions(docSession, a[1] as UserAction[]);
} else if (a[0] === 'ApplyDocActions') {
return this.canMaybeApplyUserActions(docSession, a[1] as UserAction[]);
} else if (isTableAction(a)) {
const tableId = getTableId(a);
// If there are any access control nuances, deny _grist_* tables.
// TODO: this is very crude, loosen this up appropriately.
if (tableId.startsWith('_grist_')) {
return !this.hasNuancedAccess(docSession);
}
const tableAccess = await this.getTableAccess(docSession, tableId);
const accessFn = getAccessForActionType(a);
const access = accessFn(tableAccess);
// if access is mixed, leave this to be checked in detail later.
return access === 'allow' || access === 'mixed' || access === 'mixedColumns';
}
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 hasNuancedAccess(docSession: OptDocSession): boolean {
if (!this._ruleCollection.haveRules()) { return false; }
return !this.hasFullAccess(docSession);
}
/**
* Check whether user can read everything in document. Checks both home-level and doc-level
* permissions.
*/
public async canReadEverything(docSession: OptDocSession): Promise<boolean> {
const access = getDocSessionAccess(docSession);
if (!canView(access)) { return false; }
const permInfo = await this._getAccess(docSession);
return permInfo.getFullAccess().read === 'allow';
}
/**
* Check whether user can copy everything in document. Owners can always copy
* everything, even if there are rules that specify they cannot.
*/
public async canCopyEverything(docSession: OptDocSession): Promise<boolean> {
return this.isOwner(docSession) || 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): boolean {
return this.isOwner(docSession);
}
/**
* Check whether user has owner-level access to the document.
*/
public isOwner(docSession: OptDocSession): boolean {
const access = getDocSessionAccess(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 = JSON.parse(JSON.stringify(tables));
// Collect a list of all tables (by tableRef) to which the user has no access.
const censoredTables: Set<number> = new Set();
// Collect a list of censored columns (by "<tableRef> <colId>").
const columnCode = (tableRef: number, colId: string) => `${tableRef} ${colId}`;
const censoredColumnCodes: Set<string> = new Set();
const permInfo = await this._getAccess(docSession);
for (const rec of this._docData.getTable('_grist_Tables')!.getRecords()) {
const tableId = rec.tableId as string;
const tableRef = rec.id;
const tableAccess = permInfo.getTableAccess(tableId);
if (tableAccess.read === 'deny') {
censoredTables.add(tableRef);
}
// TODO If some columns are allowed and the rest (*) are denied, we need to be able to
// censor all columns outside a set.
for (const ruleSet of this._ruleCollection.getAllColumnRuleSets(tableId)) {
if (Array.isArray(ruleSet.colIds)) {
for (const colId of ruleSet.colIds) {
if (permInfo.getColumnAccess(tableId, colId).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.
const censoredSections: Set<number> = new Set();
const censoredViews: Set<number> = new Set();
for (const section of this._docData.getTable('_grist_Views_section')?.getRecords() || []) {
if (!censoredTables.has(section.tableRef as number)) { continue; }
if (section.parentId) { censoredViews.add(section.parentId as number); }
censoredSections.add(section.id);
}
// Collect a list of all columns from tables to which the user has no access.
const censoredColumns: Set<number> = new Set();
for (const column of this._docData.getTable('_grist_Tables_column')?.getRecords() || []) {
if (censoredTables.has(column.parentId as number) ||
censoredColumnCodes.has(columnCode(column.parentId as number, column.colId as string))) {
censoredColumns.add(column.id);
}
}
// Collect a list of all fields from sections to which the user has no access.
const censoredFields: Set<number> = new Set();
for (const field of this._docData.getTable('_grist_Views_section_field')?.getRecords() || []) {
if (!censoredSections.has(field.parentId as number) &&
!censoredColumns.has(field.colRef as number)) { continue; }
censoredFields.add(field.id);
}
// Clear the tableId for any tables the user does not have access to. This is just
// to keep the name of the table private, in case its name itself is sensitive.
// TODO: tableId may appear elsewhere, such as in _grist_ACLResources - user with
// nuanced rights probably should not receive that table.
this._censor(tables._grist_Tables, censoredTables, (idx, cols) => {
cols.tableId[idx] = '';
});
// Clear the name of private views, in case the name itself is sensitive.
this._censor(tables._grist_Views, censoredViews, (idx, cols) => {
cols.name[idx] = '';
});
// Clear the title of private sections, and break the connection with the private
// table as extra grit in the way of snooping.
this._censor(tables._grist_Views_section, censoredSections, (idx, cols) => {
cols.title[idx] = '';
cols.tableRef[idx] = 0;
});
// Clear text metadata from private columns, and break the connection with the
// private table.
this._censor(tables._grist_Tables_column, censoredColumns, (idx, cols) => {
cols.label[idx] = cols.colId[idx] = '';
cols.widgetOptions[idx] = cols.formula[idx] = '';
cols.type[idx] = 'Any';
cols.parentId[idx] = 0;
});
// Clear text metadata from private fields, and break the connection with the
// private table.
this._censor(tables._grist_Views_section_field, censoredFields, (idx, cols) => {
cols.widgetOptions[idx] = cols.filter[idx] = '';
cols.parentId[idx] = 0;
});
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<TablePermissionSet> {
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 tableId = getTableId(data);
if (permInfo.getTableAccess(tableId).read === 'mixed') {
await this._filterRowsAndCells(docSession, data, data, data, canRead);
}
// Filter columns, omitting any to which the user has no access, regardless of rows.
this._filterColumns(data[3], (colId) => permInfo.getColumnAccess(tableId, colId).read !== 'deny');
}
/**
* Strip out any denied columns from an action. Returns null if nothing is left.
* accessFn may throw if denials are fatal.
*/
private _pruneColumns(a: DocAction, permInfo: PermissionInfo, tableId: string,
accessFn: AccessFn): 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) => accessFn(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 na = cloneDeep(a);
const colId: string = na[2];
if (accessFn(permInfo.getColumnAccess(tableId, colId)) === 'deny') { return null; }
throw new ErrorWithCode('NEED_RELOAD', 'document needs reload');
} else {
// Remaining cases of AddTable, RemoveTable, RenameTable should have
// been handled at the table level.
}
// TODO: handle access to changes in metadata (trigger a reload at least, if
// all else fails).
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(docSession: OptDocSession, a: DocAction, idx: number): Promise<DocAction[]> {
// For the moment, only deal with Record-related actions.
// TODO: process table/column schema changes more carefully.
if (isSchemaAction(a)) { return [a]; }
// 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).
if (!this._rowSnapshots) { throw new Error('Actions not available'); }
const allRowSnapshots = await this._rowSnapshots.get();
const [rowsBefore, rowsAfter] = allRowSnapshots[idx];
// 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 ids = new Set(getRowIdsFromDocAction(a));
const forbiddenBefores = new Set(await this._getForbiddenRows(docSession, rowsBefore, ids));
const forbiddenAfters = new Set(await this._getForbiddenRows(docSession, 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 (a[0] === 'AddRecord' || a[0] === 'BulkAddRecord' ||
a[0] === 'ReplaceTableData' || a[0] === 'TableData') {
continue;
}
// Otherwise, strip the row from the current action.
removals.add(id);
if (a[0] === 'UpdateRecord' || a[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 (a[0] === 'RemoveRecord' || a[0] === 'BulkRemoveRecord') { continue; }
// Otherwise, strip the row from the current action.
removals.add(id);
if (a[0] === 'UpdateRecord' || a[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(a, removals),
this._makeRemovals(rowsAfter, forceRemoves),
].filter(isObject);
// Return the results, also applying any cell-level access control.
for (const docAction of revisedDocActions) {
await this._filterRowsAndCells(docSession, rowsAfter, rowsAfter, docAction, canRead);
}
return revisedDocActions;
}
/**
* Like _pruneRows, but fails immediately if access to any row is forbidden.
* The accessFn supplied should throw an error on denial.
*/
private async _checkRows(docSession: OptDocSession, a: DocAction, idx: number,
accessFn: AccessFn): Promise<void> {
// For the moment, only deal with Record-related actions.
// TODO: process table/column schema changes more carefully.
if (isSchemaAction(a)) { return; }
if (!this._rowSnapshots) { throw new Error('Logic error: actions not available'); }
const allRowSnapshots = await this._rowSnapshots.get();
const [rowsBefore, rowsAfter] = allRowSnapshots[idx];
await this._filterRowsAndCells(docSession, rowsBefore, rowsAfter, a, accessFn);
}
/**
* Modify action in place, scrubbing any rows and cells to which access is not granted.
*/
private async _filterRowsAndCells(docSession: OptDocSession, rowsBefore: TableDataAction, rowsAfter: TableDataAction,
docAction: DocAction, accessFn: AccessFn) {
if (docAction && isSchemaAction(docAction)) {
// TODO should filter out metadata about an unavailable column, probably.
return [];
}
const rec = new RecordView(rowsBefore, undefined);
const newRec = new RecordView(rowsAfter, undefined);
const input: AclMatchInput = {user: await this._getUser(docSession), rec, newRec};
const [, tableId, , colValues] = docAction;
const rowIds = getRowIdsFromDocAction(docAction);
const toRemove: number[] = [];
let censorAt: (colId: string, idx: number) => void;
if (colValues === undefined) {
censorAt = () => 1;
} else if (Array.isArray(docAction[2])) {
censorAt = (colId, idx) => (colValues as BulkColValues)[colId][idx] = 'CENSORED'; // TODO Pick a suitable value
} else {
censorAt = (colId) => (colValues as ColValues)[colId] = 'CENSORED'; // TODO Pick a suitable value
}
// These map an index of a row in docAction 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 (docAction !== rowsBefore) {
const recIndexes = new Map(rowsBefore[2].map((rowId, idx) => [rowId, idx]));
getRecIndex = (idx) => recIndexes.get(rowIds[idx]);
const newRecIndexes = new Map(rowsAfter[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(this._ruleCollection, input);
// getTableAccess() evaluates all column rules for THIS record. So it's really rowAccess.
const rowAccess = rowPermInfo.getTableAccess(tableId);
const access = accessFn(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 (accessFn(colAccess) === 'deny') {
censorAt(colId, idx);
}
}
}
}
if (toRemove.length > 0) {
if (rowsBefore === docAction) {
this._removeRowsAt(toRemove, rowsBefore[2], rowsBefore[3]);
} else {
// Artificially introduced removals are ok, otherwise this is suspect.
if (docAction[0] !== 'RemoveRecord' && docAction[0] !== 'BulkRemoveRecord') {
throw new Error('Unexpected row removal');
}
}
}
}
// Compute which of the row ids supplied are for rows forbidden for this session.
private async _getForbiddenRows(docSession: OptDocSession, data: TableDataAction, ids: Set<number>):
Promise<number[]> {
const rec = new RecordView(data, undefined);
const input: AclMatchInput = {user: await this._getUser(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(this._ruleCollection, input);
// getTableAccess() evaluates all column rules for THIS record. So it's really rowAccess.
const rowAccess = rowPermInfo.getTableAccess(tableId);
if (canRead(rowAccess) === 'deny') {
toRemove.push(rowIds[idx]);
}
}
return toRemove;
}
/**
* Removes the toRemove rows (indexes, not row ids) from the rowIds list and from
* the colValues structure.
*/
private _removeRowsAt(toRemove: number[], rowIds: number[], colValues: BulkColValues|undefined) {
if (toRemove.length > 0) {
pullAt(rowIds, toRemove);
if (colValues) {
for (const values of Object.values(colValues)) {
pullAt(values, toRemove);
}
}
}
}
/**
* Remove columns from a ColumnValues parameter of certain DocActions, using a predicate for
* which columns to keep.
*/
private _filterColumns(data: BulkColValues|ColValues, shouldInclude: (colId: string) => boolean) {
for (const colId of Object.keys(data)) {
if (!shouldInclude(colId)) {
delete data[colId];
}
}
}
/**
* Modify the given TableDataAction in place by calling the supplied operation with
* the indexes of any ids supplied and the columns in that TableDataAction.
*/
private _censor(table: TableDataAction, ids: Set<number>,
op: (idx: number, cols: BulkColValues) => unknown) {
const availableIds = table[2];
const cols = table[3];
for (let idx = 0; idx < availableIds.length; idx++) {
if (ids.has(availableIds[idx])) { op(idx, cols); }
}
}
/**
* 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 getSetMapValue(this._permissionInfoMap as Map<OptDocSession, Promise<PermissionInfo>>, docSession,
async () => new PermissionInfo(this._ruleCollection, {user: await this._getUser(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 access = getDocSessionAccess(docSession);
const fullUser = getDocSessionUser(docSession);
const attrs = this._getUserAttributes(docSession);
const user: UserInfo = {};
user.Access = access;
user.UserID = 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.Link = docSession.authorizer?.getLinkParameters() || {};
// 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;
if (this._ruleCollection.ruleError && !this._recoveryMode) {
// It is important to signal that the doc is in an unexpected state,
// and prevent it opening.
throw this._ruleCollection.ruleError;
}
for (const clause of this._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;
}
/**
* 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 || -1).filter(v => v !== -1);
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]];
}
/**
* Prepare to compute intermediate states of rows, as
* this._rowSnapshots. 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._rowSnapshots.
*/
private _prepareRowSnapshots(docActions: DocAction[], undo: DocAction[]) {
// Prepare to compute row snapshots if it turns out we need them.
// If we never need them, they will never be computed.
this._rowSnapshots = new AsyncCreate(async () => {
// 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(this._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,
);
await Promise.all([...rows.keys()].map(tableId => docData.syncTable(tableId)));
if (this._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 rowSnapshots = new Array<[TableDataAction, TableDataAction]>();
for (const docAction of docActions) {
const tableId = getTableId(docAction);
const tableData = docData.getTable(tableId)!;
const before = cloneDeep(tableData.getTableDataAction());
docData.receiveAction(docAction);
// If table is deleted, state afterwards doesn't matter.
const after = docData.getTable(tableId) ? cloneDeep(tableData.getTableDataAction()) : before;
rowSnapshots.push([before, after]);
}
return rowSnapshots;
});
}
/**
* Cut out any rows/columns not accessible to the user. May throw a NEED_RELOAD
* exception if the information needed to achieve the desired pruning is not available.
* Returns null if the action is entirely pruned. The action passed in is never modified.
* The idx parameter is a record of which action in the bundle this action is, and can
* be used to access information in this._rowSnapshots if needed.
*/
private async _pruneOutgoingDocAction(docSession: OptDocSession, a: DocAction, idx: number): Promise<DocAction[]> {
const tableId = getTableId(a);
const permInfo = await this._getAccess(docSession);
const tableAccess = permInfo.getTableAccess(tableId);
const access = tableAccess.read;
if (access === 'deny') { return []; }
if (access === 'allow') { return [a]; }
if (access === 'mixedColumns') {
return [this._pruneColumns(a, permInfo, tableId, canRead)].filter(isObject);
}
// The remainder is the mixed condition.
const revisedDocActions = await this._pruneRows(docSession, a, idx);
const result = revisedDocActions.map(na => this._pruneColumns(na, permInfo, tableId,
canRead)).filter(isObject);
return result;
}
private async _checkIncomingDocAction(docSession: OptDocSession, a: DocAction, idx: number): Promise<void> {
const accessFn = denyIsFatal(getAccessForActionType(a));
const tableId = getTableId(a);
const permInfo = await this._getAccess(docSession);
const tableAccess = permInfo.getTableAccess(tableId);
const access = accessFn(tableAccess);
if (access === 'allow') { return; }
if (access === 'mixedColumns') {
// Somewhat abusing prune method by calling it with an access function that
// throws on denial.
this._pruneColumns(a, permInfo, tableId, accessFn);
}
// The remainder is the mixed condition.
await this._checkRows(docSession, a, idx, accessFn);
// Somewhat abusing prune method by calling it with an access function that
// throws on denial.
this._pruneColumns(a, permInfo, tableId, accessFn);
}
}
/**
* Evaluate a RuleSet on a given input (user and optionally record). If a record is needed but not
* included, the result may include permission values like 'allowSome', 'denySome'.
*/
function evaluateRule(ruleSet: RuleSet, input: AclMatchInput): PartialPermissionSet {
let pset: PartialPermissionSet = emptyPermissionSet();
for (const rule of ruleSet.body) {
try {
if (rule.matchFunc!(input)) {
pset = mergePartialPermissions(pset, rule.permissions);
}
} catch (e) {
if (e.code === 'NEED_ROW_DATA') {
pset = mergePartialPermissions(pset, makePartialPermissions(rule.permissions));
} else {
// For other errors, assume the rule is invalid, and treat as a non-match.
// TODO An appropriate user should be alerted that a clause is not being honored.
log.warn("ACLRule for %s failed: %s", ruleSet.tableId, e.message);
}
}
}
return pset;
}
/**
* Helper for evaluating rules given a particular user and optionally a record. It evaluates rules
* for a column, table, or document, with caching to avoid evaluating the same rule multiple times.
*/
class PermissionInfo {
private _ruleResults = new Map<RuleSet, MixedPermissionSet>();
// Construct a PermissionInfo for a particular input, which is a combination of user and
// optionally a record.
constructor(private _acls: ACLRuleCollection, private _input: AclMatchInput) {}
// Get permissions for "tableId:colId", defaulting to "tableId:*" and "*:*" as needed.
// If 'mixed' is returned, different rows may have different permissions. It should never return
// 'mixed' if the input includes `rec`.
public getColumnAccess(tableId: string, colId: string): MixedPermissionSet {
const ruleSet: RuleSet|undefined = this._acls.getColumnRuleSet(tableId, colId);
return ruleSet ? this._processColumnRule(ruleSet) : this._getTableDefaultAccess(tableId);
}
// Combine permissions from all rules for the given table.
// If 'mixedColumns' is returned, different columns have different permissions, but they do NOT
// depend on rows. If 'mixed' is returned, some permissions depend on rows.
public getTableAccess(tableId: string): TablePermissionSet {
const columnAccess = this._acls.getAllColumnRuleSets(tableId).map(rs => this._processColumnRule(rs));
columnAccess.push(this._getTableDefaultAccess(tableId));
return mergePermissions(columnAccess, (bits) => (
bits.every(b => b === 'allow') ? 'allow' :
bits.every(b => b === 'deny') ? 'deny' :
bits.every(b => b === 'allow' || b === 'deny') ? 'mixedColumns' :
'mixed'
));
}
// Combine permissions from all rules throughout.
// If 'mixed' is returned, then different tables, rows, or columns have different permissions.
public getFullAccess(): MixedPermissionSet {
const tableAccess = this._acls.getAllTableIds().map(tableId => this.getTableAccess(tableId));
tableAccess.push(this._getDocDefaultAccess());
return mergePermissions(tableAccess, (bits) => (
bits.every(b => b === 'allow') ? 'allow' :
bits.every(b => b === 'deny') ? 'deny' :
'mixed'
));
}
// Get permissions for "tableId:*", defaulting to "*:*" as needed.
// If 'mixed' is returned, different rows may have different permissions.
private _getTableDefaultAccess(tableId: string): MixedPermissionSet {
const ruleSet: RuleSet|undefined = this._acls.getTableDefaultRuleSet(tableId);
return ruleSet ? this._processRule(ruleSet, () => this._getDocDefaultAccess()) :
this._getDocDefaultAccess();
}
// Get permissions for "*:*".
private _getDocDefaultAccess(): MixedPermissionSet {
return this._processRule(this._acls.getDocDefaultRuleSet());
}
// Evaluate and cache the given column rule, falling back to the corresponding table default.
private _processColumnRule(ruleSet: RuleSet): MixedPermissionSet {
return this._processRule(ruleSet, () => this._getTableDefaultAccess(ruleSet.tableId));
}
// Evaluate the given rule, with the default fallback, and cache the result.
private _processRule(ruleSet: RuleSet, defaultAccess?: () => MixedPermissionSet): MixedPermissionSet {
return getSetMapValue(this._ruleResults, ruleSet, () => {
const pset = evaluateRule(ruleSet, this._input);
return toMixed(defaultAccess ? mergePartialPermissions(pset, defaultAccess()) : pset);
});
}
}
/**
* 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 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;
}
}
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} = {};
}
// A function for extracting one of the create/read/update/delete/schemaEdit permissions
// from a permission set.
type AccessFn = (ps: PermissionSet<string>) => string;
// Get an AccessFn appropriate for the specific action.
// TODO: deal with ReplaceTableData, which both deletes and creates rows.
function getAccessForActionType(a: DocAction): AccessFn {
if (a[0] === 'UpdateRecord' || a[0] === 'BulkUpdateRecord') {
return (ps) => ps.update;
} else if (a[0] === 'RemoveRecord' || a[0] === 'BulkRemoveRecord') {
return (ps) => ps.delete;
} else if (a[0] === 'AddRecord' || a[0] === 'BulkAddRecord') {
return (ps) => ps.create;
} else {
return (ps) => ps.schemaEdit;
}
}
// Tweak an AccessFn so that it throws an exception if access is denied.
function denyIsFatal(fn: AccessFn): AccessFn {
return (ps) => {
const result = fn(ps);
if (result === 'deny') { throw new Error('access denied'); }
return result;
};
}
// A simple access function that returns the "read" permission.
function canRead(ps: PermissionSet<string>) {
return ps.read;
}