Summary:
Currently actions blocked early because they could modify the
schema (e.g. changing formulas) do not report memo information
(comments in relevant rules). This diff fixes that by using
more of the same code path in the two situations. It also
adds information about what type of action was blocked to
error messages.
Test Plan: extended a test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2995
Summary:
Currently, if access rules are set to allow edits unconditionally,
and an owner does "View As" a user who is a viewer only, they will
be allowed to make edits. This catches that condition and adds a
test.
Test Plan: added test
Reviewers: georgegevoian
Reviewed By: georgegevoian
Differential Revision: https://phab.getgrist.com/D2991
Summary:
Prefix keys of `LinkingState.filterColValues` with `_contains:` when the source column is a ChoiceList or ReferenceList.
This is parsed out to make a boolean `isContainsFilter` which is kept in each value of `QueryRefs.filterTuples` (previously `filterPairs`).
Then when converting back in `convertQueryFromRefs` we construct `Query.contains: {[colId: string]: boolean}`.
Finally `getFilterFunc` uses `Query.contains` to decide what kind of filtering to do.
This is not pretty, but the existing code is already very complex and it was hard to find something that wouldn't require touching loads of code just to make things compile.
Test Plan: Added a new nbrowser test and fixture, tests that selecting a source table by summary tables grouped by a choicelist column, non-list column, and both all filter the correct data.
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2940
Summary:
Exceptional sessions had lost full read access to documents; this
restores it. Exceptional sessions are used for system actions or
while creating documents.
Test Plan: added test
Reviewers: alexmojaki
Reviewed By: alexmojaki
Differential Revision: https://phab.getgrist.com/D2966
Summary:
Processing these calls in the client, rather than passing them on
to the backend, means that access rules are more straightforward to
apply.
An unrelated fix is included to filter _grist_ tables when fetched
individually - metadata could leak through this path.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2954
Summary:
This tweaks pre-fork mode to make the user's experience a bit more seamless.
Pre-fork mode is where the user has opened a document with intent to
fork it, but actual forking (with allocation of a new document id)
is postponed until they make their first change.
The tweak makes the user an owner for granular access purposes, if
forking is permitted. So data visible only to owners because of
access rules will be visible to them. As always, any edits would
go to a separate new copy.
A remaining tricky corner is what to do about "View As" functionality
on forks. Fork sharing cannot be controlled, so the "Users -> View As"
functionality isn't available. Perhaps the "Users" button on a fork
could encourage doing a save-copy and inviting users, or offer some
dummy users? In any case, this diff doesn't change anything with
that corner.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2931
Summary:
The 'user' variable has a similar API to the one from access rules: it
contains properties about a user, such as their full name and email
address, as well as optional, user-defined attributes that are populated
via user attribute tables.
Test Plan: Python unit tests.
Reviewers: alexmojaki, paulfitz, dsagal
Reviewed By: alexmojaki, dsagal
Subscribers: paulfitz, dsagal, alexmojaki
Differential Revision: https://phab.getgrist.com/D2898
Summary:
This is a somewhat experimental change, that will implement permitted parts of an undo if not all parts are permitted. This is in preparation for trigger columns, where it may become common for a change in a record resulting in a change to an automatic change to another that the user cannot edit directly. How to undo such an action is somewhat unclear. One option is to undo the permitted parts, and then the triggers can rerun.
The general case is a bit of a can of worms, and feels adjacent to merging/rebasing etc.
Oh: it would probably be important in general to communicate to the user that an undo was partial, but this diff doesn't do that. It would need some new plumbing.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2839
Test Plan: Block read access to column A based on the condition rec.B == 1. Then setting B = 1 in a row makes the cell under A grey.
Reviewers: dsagal
Reviewed By: dsagal
Subscribers: paulfitz, dsagal
Differential Revision: https://phab.getgrist.com/D2828
Summary:
We used tslint earlier, and on switching to eslint, some rules were not
transfered. This moves more rules over, for consistent conventions or helpful
warnings.
- Name private members with a leading underscore.
- Prefer interface over a type alias.
- Use consistent spacing around ':' in type annotations.
- Use consistent spacing around braces of code blocks.
- Use semicolons consistently at the ends of statements.
- Use braces around even one-liner blocks, like conditionals and loops.
- Warn about shadowed variables.
Test Plan: Fixed all new warnings. Should be no behavior changes in code.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2831
Summary:
Currently, to compute intermediate steps in a bundle, the bundle
is sent to the data engine to process. Then, if the intermediate
steps break a rule, it is reverted. One problem introduced by
checking permissions this late is that the data engine can be
exposed for formulas with python code by users who don't have the
right to change formulas. This diff pre-checks cases that change
formulas.
Test Plan: added a test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2816
Summary: For row creations and deletions, treat `rec` and `newRec` variables as identical. This simplifies writing a single rule that controls multiple permissions.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2812
Summary:
This diff discounts indirect changes for access control purposes. A UserAction that updates a cell A, which in turn causes changes in other dependent cells, will be considered a change to cell A for access control purposes.
The `engine.apply_user_actions` method now returns a `direct` array, with a boolean for each `stored` action, set to `true` if the action is attributed to the user or `false` if it is attributed to the engine. `GranularAccess` ignores actions attributed to the engine when checking for edit rights.
Subtleties:
* Removal of references to a removed row are considered direct changes.
* Doesn't play well with undos as yet. An action that indirectly modifies a cell the user doesn't have rights to may succeed, but it will not be reversible.
Test Plan: added tests, updated tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2806
Summary:
Exceptional document operations (particularly `system` and `nascent`
operations) should never be denied by a granular access rule.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2792
Summary: Access to structural tables currently depends on SchemaEdit permission. We now make an exception for owner access to _grist_ACLResources and _grist_ACLRules, giving them unconditional access. It was too easy for owners to lock themselves out of editing access rules.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2790
Summary:
- Update rules to be more like we've had with tslint
- Switch tsserver plugin to eslint (tsserver makes for a much faster way to lint in editors)
- Apply suggested auto-fixes
- Fix all lint errors and warnings in core/, app/, test/
Test Plan: Some behavior may change subtly (e.g. added missing awaits), relying on existing tests to catch problems.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2785
Summary:
This removes some unintentional repetition of work when there are
no row-level rules (there was a missing `return`).
Test Plan: existing tests pass
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2782
Summary: This addresses a weakness in the following case: rules controlling view access for a column, with a dependency on the values of other columns. We had disabled support for such rules, since the existing implementation worked only on table loads and not on broadcast changes. This diff adds in logic to enrich broadcasts as needed, and allows such rules.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2774
Summary:
When adding robustness to schema changes to granular access control,
a calculation of intermediate row states that was previously done
semi-intelligently on need started happening less intelligently.
This diff separates out the row state calculations from metadata
state calculations so that one can happen without the other.
Test Plan: extended a test. Also did some manual checks.
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2773
Summary:
For a long array with removals proportional to that length,
lodash/pullAt becomes slow due to doing one splice per removal.
This diff swaps in an alternate implementation that doesn't become
quadratic. On a 250k-row doc with a row-level access rule, this improves
initial page load for a viewer with access to half the rows from minutes
to seconds.
Test Plan: added test; did manual benchmarking
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2777
Summary:
This allows `*SPECIAL:AccessRules` to give read access to the access rules to more users, and `*SPECIAL:FullCopies` to grant download/copy rights to more users.
This diff also changes forks to be owned by the user who forked them (previously they were an editor), since that feels more natural.
Test Plan: Added and updated tests.
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2760
Summary:
- Use special ACLResources of the form "*SPECIAL:<RuleType>" to represent
special document-wide rules.
- Include default rules that give Read access to these resources to Owners only.
- Add UI with a checkbox to give access to everyone instead.
- Allow expanding the UI for advanced configuration.
- These rules don't actually have any behavior yet.
Test Plan: WIP
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2764
Summary:
* Adds a `SELF_HYPERLINK()` python function, with optional keyword arguments to set a label, the page, and link parameters.
* Adds a `UUID()` python function, since using python's uuid.uuidv4 hits a problem accessing /dev/urandom in the sandbox. UUID makes no particular quality claims since it doesn't use an audited implementation. A difficult to guess code is convenient for some use cases that `SELF_HYPERLINK()` enables.
The canonical URL for a document is mutable, but older versions generally forward. So for implementation simplicity the document url is passed it on sandbox creation and remains fixed throughout the lifetime of the sandbox. This could and should be improved in future.
The URL is passed into the sandbox as a `DOC_URL` environment variable.
The code for creating the URL is factored out of `Notifier.ts`. Since the url is a function of the organization as well as the document, some rejiggering is needed to make that information available to DocManager.
On document imports, the new document is registered in the database slightly earlier now, in order to keep the procedure for constructing the URL in different starting conditions more homogeneous.
Test Plan: updated test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2759
Summary:
Now as the user an owner might choose to view their document as
is likely to not have access to rules, it is better to start
viewing on the default document page rather than /p/acl.
The "Access Rules" link is grayed out when in "view as" mode for
now (improvements are planned).
Test Plan: updated test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2743
Summary:
Previously, if some columns are allowed and the rest are denied,
the client could see unnecessary blank columns. This diff cleans
up column metadata censorship. It also adds a small tweak to
retain the `manualSort` column when filtering columns for a mixed
access table.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2742
Summary:
- Support schema changes in the presence of non-trivial ACL rules.
- Fix update of `aclFormulaParsed` when updating formulas automatically after schema change.
- Filter private metadata in broadcasts, not just fetches. Censorship method is unchanged, just refactored.
- Allow only owners to change ACL rules.
- Force reloads if rules are changed.
- Track rule changes within bundle, for clarity during schema changes - tableId and colId changes create a muddle otherwise.
- Show or forbid pages dynamically depending on user's access to its sections. Logic unchanged, just no longer requires reload.
- Fix calculation of pre-existing rows touched by a bundle, in the presence of schema changes.
- Gray out acl page for non-owners.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2734
Summary:
With this change, if a comment is added to an ACL formula, then that comment will be offered to the user if access is denied and that rule could potentially have granted access.
The code is factored so that when access is permitted, or when partially visible tables are being filtered, there is little overhead. Comments are gathered only when an explicit denial of access.
Test Plan: added tests, updated tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2730
Test Plan: Added a test case to tickle the bug this was causing.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2718
Summary:
- This replaces the message "Unexpected Error / Access Denied / Report a problem" with a
one-line "Blocked by access rules".
Test Plan: Only tested manually
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2712
Summary:
This redefines `newRec` to be the state at the end of a bundle,
for the purposes of modifying a document. Updates and adds tests
for creation/updates of rows that are now more intuitive hopefully.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2707
Summary:
This adds back-end support for query parameters `aclAsUser_` and
`aclAsUserId_` which, when either is present, direct Grist to
process granular access control rules from the point of view
of that user (specified by email or id respectively).
Some front end support is added, in the form of a tag that
shows up when in this mode, and a way to cancel the mode.
No friendly way to initiate the mode is offered yet.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2704
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
Summary:
- Placed rule-updating functions in acl.py.
- Reset UI when rules update externally, or alert the user to reset if there
are pending local changes.
- Removed some unused and distracting bits from client-side DocModel.
A few improvements related to poor error handling:
- In case of missing DocActions (tickled by broken ACL rule handling), don't
add to confusion by attempting to process bad actions
- In case of missing attributes in ACL formulas, return undefined rather than
fail; the latter creates more problems.
- In case in invalid rules, fail rather than skip; this feels more correct now
that we have error checking and recovery option, and helps avoid invalid rules.
- Prevent saving invalid rules with an empty ACL formula.
- Fix bug with rule positions.
Test Plan: Added a python and browser test for table/column renames.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2698
Summary:
- Add headers to tables.
- Change styles to reduce boxes-within-boxes.
- Add validation of table and column IDs, both in UI and on server when saving rules.
- Add autocomplete for tables/columns used for UserAttribute rules.
- Add a fancy widget to set permission bits.
Test Plan: Updated browser test for new UI, added a test case for user attributes.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2695
Summary:
The client relies on metadata tables for laying out pages and sections.
These tables are filtered according to what tables the user has access
to, in a crude way. This diff updates the logic to at least support
the table wildcard.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2690
Summary:
- Fix error-handling in bundleActions(), and wait for the full bundle to complete.
(The omissions here were making it impossibly to react to errors from inside bundleActions())
- Catch problematic rules early enough to undo them, by trying out ruleCollection.update()
on updated rules before the updates are applied.
- Added checkAclFormula() call to DocComm that checks parsing and compiling
formula, and reports errors.
- In UI, prevent saving if any aclFormulas are invalid, or while waiting for the to get checked.
- Also fixed some lint errors
Test Plan: Added a test case of error reporting in ACL formulas.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2689
Summary:
Adds an "enter safe mode" option and explanation in modal that appears when a document fails to load, if user is owner. If "enter safe mode" is selected, document is reloaded on server in a special mode. Currently, the only difference is that if the acl rules fail to load, they are replaced with a fallback that grants full access to owners and no access to anyone else. An extra tag is shown to mark the document as safe mode, with an "x" for cancelling safe mode.
There are other ways a document could fail to load than just acl rules, so this is just a start.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2686
Summary:
This changes how user attributes are loaded. They are now loaded
directly from sqlite, with per-session caching. Optimizations
considered but not addressed yet are (1) adding indexes to user attribute
tables and (2) swapping in a thinner sqlite wrapper.
The main benefit of this diff is that changes to user attribute
tables now work. Clients whose user attributes are not changed
see no effect; clients whose user attributes have changed have
their document reloaded.
For the purposes of testing, the diff includes a tweak to
GristWSConnection to be "sticky" to a specific user when reloading
(and support machinery on the server side to honor that). Until
now, if a GristWSConnection reloads, it uses whatever the current
default user is in the cookie-based session, which can change.
This was complicating a test where multiple users were accessing
the same document via different clients with occasional document
reloads.
Code for updating when schema or rule changes happen is moved
around but not improved in any meaningful way in this diff.
Test Plan: existing tests pass; extended test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2685
Summary:
This adds any parameters in a document url whose key ends in '_'
into a `user.Link` object available in access control formulas
and in setting up characteristic tables.
This allows, for example, sending links to a document that contain
a hard-to-guess token, and having that link grant access to a
controlled part of the document (invoices for a specific customer
for example).
A `user.Origin` field is also added, set during rest api calls,
but is only tested manually at this point. It could be elaborated
for embedding use-cases.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2680
Summary:
This improves support for access control on document modifications. It adds:
* Checking of create/remove/update access for row-level changes.
* Use of `newRec` variable in formulas.
It is now possible to have distinct clients with read+write access to different rows of the same table.
This is another incremental step. There are deficiencies in actions that include schema changes, and many other lacunae. But the overall flow is taking shape.
Access control is done at the DocAction level, requiring the sandbox to process the UserActions, and then be reverted if the action proves unlawful. This could be optimized away in many simple and important cases, but I'm not sure it is possible to avoid in general.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2677
Summary:
- Factored out ACLRuleCollection into its own file, and use for building UI.
- Moved AccessRules out of UserManager to a page linked from left panel.
- Changed default RulePart to be the last part of a rule for simpler code.
- Implemented much of the UI for adding/deleting rules.
- For now, editing the ACLFormula and Permissions is done using text inputs.
- Implemented saving rules by syncing a bundle of them.
- Fixed DocData to clean up action bundle in case of an early error.
Test Plan: WIP planning to add some new browser tests for the UI
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2678
Summary:
This implements row-level access control for outgoing messages, replacing the document reloading placeholder that was there before.
* Prior to broadcasting messages, GranularAccess is notified of actions+undo.
* While broadcasting messages to different sessions, if we find we need row level access control information, rows before and after the change are reconstructed.
* Messages are rewritten if rows that were previously forbidden are now allowed, and vice versa.
The diff is somewhat under-tested and under-optimized. Next step would be to implement row-level access control for incoming actions, which may result in some rejiggering of the code from this diff to avoid duplication of effort under some conditions.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2670
Summary:
- Added fields to _grist_ACLRules for the new Granular ACL representation
- Include a corresponding migration.
- Added ACLPermissions module with merging PermissionSets and converting to/from string.
- Implemented parsing of ACL formulas and compiling them into JS functions.
- Add automatic parsing of ACL formulas when ACLRules are added or updated.
- Convert GranularAccess to load and interpret new-style rules.
- Convert ACL UI to load and save new-style rules.
For now, no attempt to do anything better on the server or UI side, only to
reproduce previous behavior.
Test Plan: Added unittests for new files; fixed those for existing files.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2664
Summary:
The new plans for granular access control are different and handled by
node.js. Some of the same tables will be reused, of which we never made
real use before except for expecting certain specific initial records.
This diff removes the old logic, replacing it with a stub that satisfies
the interface expected by other code.
It also removes several unused UserActions: AddUser/RemoveUser/
AddInstance/RemoveInstance.
Test Plan: Existing tests should pass.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2662
Summary: Adds a granular access clause for columns. Permissions can be specified for a set of columns within a table. Permissions accumulate over clauses, in a way that is intended as a placeholder pending final design.
Test Plan: Added tests. Tested manually that updates to private columns are not sent to people who don't have access to them. There are a lot of extra tests needed and TODOs to be paid down after this experimental phase.
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2651
Summary:
This is a prototype for expanding the conditions that can be used in granular ACLs.
When processing ACLs, the following variables (called "characteristics") are now available in conditions:
* UserID
* Email
* Name
* Access (owners, editors, viewers)
The set of variables can be expanded by adding a "characteristic" clause. This is a clause which specifies:
* A tableId
* The name of an existing characteristic
* A colId
The effect of the clause is to expand the available characteristics with all the columns in the table, with values taken from the record where there is a match between the specified characteristic and the specified column.
Existing clauses are generalized somewhat to demonstrate and test the use these variables. That isn't the main point of this diff though, and I propose to leave generalizing+systematizing those clauses for a future diff.
Issues I'm not dealing with here:
* How clauses combine. (The scope on GranularAccessRowClause is a hack to save me worrying about that yet).
* The full set of matching methods we'll allow.
* Refreshing row access in clients when the tables mentioned in characteristic tables change.
* Full CRUD permission control.
* Default rules (part of combination).
* Reporting errors in access rules.
That said, with this diff it is possible to e.g. assign a City to editors by their email address or name, and have only rows for those Cities be visible in their client. Ability to modify those rows, and remain updates about them, remains under incomplete control.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2642
Summary:
This implements a form of row-level access control where for a
given table, you may specify that only owners have access to
rows for which a given column has falsy values.
For simplicity:
* Only owners may edit that table.
* Non-owners with the document open will have forced
reloads whenever the table is modified.
Baby steps...
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2633
Summary:
AccessRules class that implements that UI is intended to look vaguely like
detailed rules might look in the future, but only supports the very limited set
we have now.
In addition, UserManager and BillingPage code is separated into their own webpack bundles, to reduce the sizes of primary bundles, and relevant code from them is loaded asynchronously.
Also add two TableData methods: filterRowIds() and findMatchingRowId().
Test Plan: Only tested manually, proper automated tests don't seem warranted for this temporary UI.
Reviewers: paulfitz
Reviewed By: paulfitz
Differential Revision: https://phab.getgrist.com/D2620
Summary:
This is an incremental step in granular access control. Using
a temporary `{colIds: '~o structure'}` representation in the
`_grist_ACLResources` table, the document structure can be set
to be controlled by owners only.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2613
Summary:
This makes it possible to serve a table or tables only to owners.
* The _grist_ACLResources table is abused (temporarily) such that rows of the form `{colId: '~o', tableId}` are interpreted as meaning that `tableId` is private to owners.
* Many websocket and api endpoints are updated to preserve the privacy of these tables.
* In a document where some tables are private, a lot of capabilities are turned off for non-owners to avoid leaking info indirectly.
* The client is tweaked minimally, to show '-' where a page with some private material would otherwise go.
No attempt is made to protect data from private tables pulled into non-private tables via formulas.
There are some known leaks remaining:
* Changes to the schema of private tables are still broadcast to all clients (fixable).
* Non-owner may be able to access snapshots or make forks or use other corners of API (fixable).
* Changing name of table makes it public, since tableId in ACLResource is not updated (fixable).
Security will require some work, the attack surface is large.
Test Plan: added tests
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2604
