(core) add a user.SessionID value for trigger formulas and granular access rules

Summary:
This makes a `user.SessionID` value available in information about the user, for use with trigger formulas and granular access rules. The ID should be constant within a browser session for anonymous user. For logged in users it simply reflects their user id.

This ID makes it possible to write access rules and trigger formulas that allow different anonymous users to create, view, and edit their own records in a document.

For example, you could have a brain-storming document for puns, and allow anyone to add to it (without logging in), letting people edit their own records, but not showing the records to others until they are approved by a moderator. Without something like this, we could only let anonymous people add one field of a record, and not have a secure way to let them edit that field or others in the same record.

Also adds a `user.IsLoggedIn` flag in passing.

Test Plan: Added a test, updated tests. The test added is a mini-moderation doc, don't use it for real because it allows users to edit their entries after a moderator has approved them.

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: dsagal

Differential Revision: https://phab.getgrist.com/D3273

app/client/aclui/AccessRules.ts

@@ -143,6 +143,8 @@ export class AccessRules extends Disposable {
         {ruleIndex: -1, value: 'user.Name'},
         {ruleIndex: -1, value: 'user.LinkKey.'},
         {ruleIndex: -1, value: 'user.Origin'},
+        {ruleIndex: -1, value: 'user.SessionID'},
+        {ruleIndex: -1, value: 'user.IsLoggedIn'},
       ];
       for (const [i, rule] of rules.entries()) {
         const tableId = use(rule.tableId);

app/server/lib/Authorizer.ts

@@ -11,6 +11,7 @@ import {forceSessionChange, getSessionProfiles, getSessionUser, getSignInStatus,
 import {RequestWithOrg} from 'app/server/lib/extractOrg';
 import {COOKIE_MAX_AGE, getAllowedOrgForSessionID, getCookieDomain,
         cookieName as sessionCookieName} from 'app/server/lib/gristSessions';
+import {makeId} from 'app/server/lib/idUtils';
 import * as log from 'app/server/lib/log';
 import {IPermitStore, Permit} from 'app/server/lib/Permit';
 import {allowHost, optStringParam} from 'app/server/lib/requestUtils';
@@ -30,6 +31,7 @@ export interface RequestWithLogin extends Request {
   userIsAuthorized?: boolean;   // If userId is for "anonymous", this will be false.
   docAuth?: DocAuthResult;      // For doc requests, the docId and the user's access level.
   specialPermit?: Permit;
+  altSessionId?: string;   // a session id for use in trigger formulas and granular access rules
 }
 
 /**
@@ -154,6 +156,12 @@ export async function addRequestUser(dbManager: HomeDBManager, permitStore: IPer
   // If we haven't selected a user by other means, and have profiles available in the
   // session, then select a user based on those profiles.
   const session = mreq.session;
+  if (session && !session.altSessionId) {
+    // Create a default alternative session id for use in documents.
+    session.altSessionId = makeId();
+    forceSessionChange(session);
+  }
+  mreq.altSessionId = session?.altSessionId;
   if (!mreq.userId && session && session.users && session.users.length > 0 &&
      mreq.org !== undefined) {
 

app/server/lib/BrowserSession.ts

@@ -53,6 +53,13 @@ export interface SessionObj {
 
   // This gets set to encourage express-session to set a cookie. Was a boolean in the past.
   alive?: number;
+
+  altSessionId?: string;  // An ID unique to the session, but which isn't related
+                          // to the session id used to lookup the cookie. This ID
+                          // is suitable for embedding in documents that allows
+                          // anonymous editing (e.g. to allow the user to edit
+                          // something they just added, without allowing the suer
+                          // to edit other people's contributions).
 }
 
 // Make an artificial change to a session to encourage express-session to set a cookie.
@@ -138,6 +145,7 @@ export function linkOrgWithEmail(session: SessionObj, email: string, org: string
 export class ScopedSession {
   private _sessionCache?: SessionObj;
   private _live: boolean;  // if set, never cache session in memory.
+  private _altSessionId?: string;
 
   /**
    * Create an interface to the session identified by _sessionId, in the store identified
@@ -220,6 +228,10 @@ export class ScopedSession {
     await this._setSession(req, session);
   }
 
+  public getAltSessionId(): string | undefined {
+    return this._altSessionId;
+  }
+
   /**
    * Read the state of the session.
    */
@@ -227,6 +239,7 @@ export class ScopedSession {
     if (this._sessionCache) { return this._sessionCache; }
     const session = ((await this._sessionStore.getAsync(this._sessionId)) || {}) as SessionObj;
     if (!this._live) { this._sessionCache = session; }
+    this._altSessionId = session.altSessionId;
     return session;
   }
 

app/server/lib/Client.ts

@@ -234,6 +234,10 @@ export class Client {
     return this._session;
   }
 
+  public getAltSessionId(): string|undefined {
+    return this._session?.getAltSessionId();
+  }
+
   public destroy() {
     this._destroyed = true;
   }

app/server/lib/DocSession.ts

@@ -101,6 +101,16 @@ export function getDocSessionUserId(docSession: OptDocSession): number|null {
   return null;
 }
 
+export function getDocSessionAltSessionId(docSession: OptDocSession): string|null {
+  if (docSession.req) {
+    return docSession.req.altSessionId || null;
+  }
+  if (docSession.client) {
+    return docSession.client.getAltSessionId() || null;
+  }
+  return null;
+}
+
 /**
  * Get as much of user profile as we can (id, name, email).
  */

app/server/lib/GranularAccess.ts

@@ -22,7 +22,8 @@ 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, getDocSessionUser, OptDocSession } from 'app/server/lib/DocSession';
+import { getDocSessionAccess, getDocSessionAltSessionId, getDocSessionUser,
+         OptDocSession } from 'app/server/lib/DocSession';
 import * as log from 'app/server/lib/log';
 import { IPermissionInfo, PermissionInfo, PermissionSetWithContext } from 'app/server/lib/PermissionInfo';
 import { TablePermissionSetWithContext } from 'app/server/lib/PermissionInfo';
@@ -1356,7 +1357,9 @@ export class GranularAccess implements GranularAccessForBundle {
     }
     const user = new User();
     user.Access = access;
-    user.UserID = fullUser?.id || null;
+    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.
@@ -1365,6 +1368,8 @@ export class GranularAccess implements GranularAccessForBundle {
     // 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,

sandbox/grist/test_completion.py

@@ -10,7 +10,9 @@ class TestCompletion(test_engine.EngineTestCase):
     'LinkKey': {},
     'Origin': None,
     'Email': 'foo@example.com',
-    'Access': 'owners'
+    'Access': 'owners',
+    'SessionID': 'u1',
+    'IsLoggedIn': True
   }
 
   def setUp(self):
@@ -85,9 +87,11 @@ class TestCompletion(test_engine.EngineTestCase):
       [
         'user.Access',
         'user.Email',
+        'user.IsLoggedIn',
         'user.LinkKey',
         'user.Name',
         'user.Origin',
+        'user.SessionID',
         'user.StudentInfo',
         'user.UserID'
       ]
@@ -114,16 +118,20 @@ class TestCompletion(test_engine.EngineTestCase):
       'Email': 'baro@example.com',
       'LinkKey': {},
       'UserID': 2,
-      'Access': 'owners'
+      'Access': 'owners',
+      'SessionID': 'u2',
+      'IsLoggedIn': True
     }
     self.assertEqual(
       self.engine.autocomplete("user.", "Schools", "lastModified", user2),
       [
         'user.Access',
         'user.Email',
+        'user.IsLoggedIn',
         'user.LinkKey',
         'user.Name',
         'user.Origin',
+        'user.SessionID',
         'user.UserID'
       ]
     )

sandbox/grist/test_renames.py

@@ -314,7 +314,9 @@ class TestRenames(test_engine.EngineTestCase):
       'LinkKey': {},
       'Origin': None,
       'Email': 'foo@example.com',
-      'Access': 'owners'
+      'Access': 'owners',
+      'SessionID': 'u1',
+      'IsLoggedIn': True
     }
 
     # Renaming a table should not leave the old name available for auto-complete.

sandbox/grist/test_trigger_formulas.py

@@ -566,7 +566,9 @@ class TestTriggerFormulas(test_engine.EngineTestCase):
       'LinkKey': {},
       'Origin': None,
       'Email': 'foo.bar@getgrist.com',
-      'Access': 'owners'
+      'Access': 'owners',
+      'SessionID': 'u1',
+      'IsLoggedIn': True
     }
     user2 = {
       'Name': 'Baz Qux',
@@ -575,7 +577,9 @@ class TestTriggerFormulas(test_engine.EngineTestCase):
       'LinkKey': {},
       'Origin': None,
       'Email': 'baz.qux@getgrist.com',
-      'Access': 'owners'
+      'Access': 'owners',
+      'SessionID': 'u2',
+      'IsLoggedIn': True
     }
     # Use formula to store last modified by data (user name and email). Check that it works as expected.
     self.load_sample(self.sample)

sandbox/grist/test_user.py

@@ -19,7 +19,9 @@ class TestUser(test_engine.EngineTestCase):
         'Param2': 'Param2Value'
       },
       'Origin': 'https://getgrist.com',
-      'StudentInfo': ['Students', 1]
+      'StudentInfo': ['Students', 1],
+      'SessionID': 'u1',
+      'IsLoggedIn': True
     }
     u = User(data, self.engine.tables)
     self.assertEqual(u.Name, 'Foo Bar')
@@ -45,7 +47,9 @@ class TestUser(test_engine.EngineTestCase):
         'Param2': 'Param2Value'
       },
       'Origin': 'https://getgrist.com',
-      'StudentInfo': ['Students', 1]
+      'StudentInfo': ['Students', 1],
+      'SessionID': 'u1',
+      'IsLoggedIn': True
     }
     u = User(data, self.engine.tables, is_sample=True)
     self.assertEqual(u.StudentInfo.id, 0)

sandbox/grist/user.py

@@ -17,6 +17,8 @@ the following fields:
  - Name: string or None
  - Origin: string or None
  - LinkKey: dictionary
+ - SessionID: string or None
+ - IsLoggedIn: boolean
 
 Additional keys may be included, which may have a value that is
 either None or of type tuple with the following shape:
@@ -40,7 +42,8 @@ class User(object):
   typed equivalents, for use by autocompletion.
   """
   def __init__(self, data, tables, is_sample=False):
-    for attr in ('Access', 'UserID', 'Email', 'Name', 'Origin'):
+    for attr in ('Access', 'UserID', 'Email', 'Name', 'Origin', 'SessionID',
+                 'IsLoggedIn'):
       setattr(self, attr, data[attr])
 
     self.LinkKey = LinkKey(data['LinkKey'])