Fixes issue affecting linking users to a 3rd party auth (#4047)

* Fixes issue affecting linking users to a 3rd party auth

* Fixes problematic test

* Better fix

* nits

spec/AuthenticationAdapters.spec.js

@@ -71,6 +71,10 @@ describe('AuthenticationProviers', function() {
   });
 
   var createOAuthUser = function(callback) {
+    return createOAuthUserWithSessionToken(undefined, callback);
+  }
+
+  var createOAuthUserWithSessionToken = function(token, callback) {
     var jsonBody = {
       authData: {
         myoauth: getMockMyOauthProvider().authData
@@ -81,18 +85,27 @@ describe('AuthenticationProviers', function() {
       headers: {'X-Parse-Application-Id': 'test',
         'X-Parse-REST-API-Key': 'rest',
         'X-Parse-Installation-Id': 'yolo',
+        'X-Parse-Session-Token': token,
         'Content-Type': 'application/json' },
       url: 'http://localhost:8378/1/users',
-      body: JSON.stringify(jsonBody)
+      body: jsonBody,
+      json: true
     };
 
-    return request.post(options, callback);
+    return new Promise((resolve) => {
+      request.post(options, (err, res, body) => {
+        resolve({err, res, body});
+        if (callback) {
+          callback(err, res, body);
+        }
+      });
+    });
   }
 
   it("should create user with REST API", done => {
     createOAuthUser((error, response, body) => {
       expect(error).toBe(null);
-      var b = JSON.parse(body);
+      var b = body;
       ok(b.sessionToken);
       expect(b.objectId).not.toBeNull();
       expect(b.objectId).not.toBeUndefined();
@@ -118,14 +131,14 @@ describe('AuthenticationProviers', function() {
     var objectId;
     createOAuthUser((error, response, body) => {
       expect(error).toBe(null);
-      var b = JSON.parse(body);
+      var b = body
       expect(b.objectId).not.toBeNull();
       expect(b.objectId).not.toBeUndefined();
       objectId = b.objectId;
 
       createOAuthUser((error, response, body) => {
         expect(error).toBe(null);
-        var b = JSON.parse(body);
+        var b = body;
         expect(b.objectId).not.toBeNull();
         expect(b.objectId).not.toBeUndefined();
         expect(b.objectId).toBe(objectId);
@@ -134,6 +147,22 @@ describe('AuthenticationProviers', function() {
     });
   });
 
+  it("should fail to link if session token don't match user", (done) => {
+    Parse.User.signUp('myUser', 'password').then((user) => {
+      return createOAuthUserWithSessionToken(user.getSessionToken());
+    }).then(() => {
+      return Parse.User.logOut();
+    }).then(() => {
+      return Parse.User.signUp('myUser2', 'password');
+    }).then((user) => {
+      return createOAuthUserWithSessionToken(user.getSessionToken());
+    }).then(({ body }) => {
+      expect(body.code).toBe(208);
+      expect(body.error).toBe('this auth is already used');
+      done();
+    }).catch(done.fail);
+  });
+
   it("unlink and link with custom provider", (done) => {
     var provider = getMockMyOauthProvider();
     Parse.User._registerAuthenticationProvider(provider);

spec/ParseUser.spec.js

@@ -1185,10 +1185,7 @@ describe('Parse.User testing', () => {
       expect(fileAgain.url()).toMatch(/yolo.txt$/);
     }).then(() => {
       done();
-    }, error => {
+    }).catch(done.fail);
-      jfail(error);
-      done();
-    });
   });
 
   it("log in with provider twice", (done) => {

src/RestWrite.js

@@ -297,7 +297,14 @@ RestWrite.prototype.handleAuthData = function(authData) {
         }
       });
       const hasMutatedAuthData = Object.keys(mutatedAuthData).length !== 0;
-      if (!this.query) {
+      let userId;
+      if (this.query && this.query.objectId) {
+        userId = this.query.objectId;
+      } else if (this.auth && this.auth.user && this.auth.user.id) {
+        userId = this.auth.user.id;
+      }
+      if (!userId || userId === userResult.objectId) { // no user making the call
+        // OR the user making the call is the right one
         // Login with auth data
         delete results[0].password;
 
@@ -328,10 +335,10 @@ RestWrite.prototype.handleAuthData = function(authData) {
           // Just update the authData part
           return this.config.database.update(this.className, {objectId: this.data.objectId}, {authData: mutatedAuthData}, {});
         });
-      } else if (this.query && this.query.objectId) {
+      } else if (userId) {
         // Trying to update auth data but users
         // are different
-        if (userResult.objectId !== this.query.objectId) {
+        if (userResult.objectId !== userId) {
           throw new Parse.Error(Parse.Error.ACCOUNT_ALREADY_LINKED,
             'this auth is already used');
         }