MM-11327: Restrict Teams by Email (#9142)

* Check a team's AllowedDomains setting before adding users to the team.

* Updated AddUser tests to validate AllowedDomains restriction.

* Updated variable name to match convention.

* Removed AllowedDomains from team sanitization.

* Update AppError's Where to match the calling function.

* Added tests for user matching allowedDomains, and multi domain values of allowedDomains.

* Added test to make sure we block users who have a subdomain of a whitelisted domain.

* Revert "Removed AllowedDomains from team sanitization."

This reverts commit 17c2afea584da40c7d769787ae86408e9700510c.

* Update sanitization tests to include dockerhost, now that we enforce AllowedDomains.

* Added tests to verify the interplay between the global and per team domain restrictions.

* Validate AllowedDomains property against RestrictCreationToDomains before updating a team.

* Remove team.AllowedDomains from sanitization.

* Add i18n string for the team allowed domains restriction app error.

api4/team_test.go

@@ -96,15 +96,13 @@ func TestCreateTeamSanitization(t *testing.T) {
 			Name:           GenerateTestTeamName(),
 			Email:          th.GenerateTestEmail(),
 			Type:           model.TEAM_OPEN,
-			AllowedDomains: "simulator.amazonses.com",
+			AllowedDomains: "simulator.amazonses.com,dockerhost",
 		}
 
 		rteam, resp := th.Client.CreateTeam(team)
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 
@@ -114,15 +112,13 @@ func TestCreateTeamSanitization(t *testing.T) {
 			Name:           GenerateTestTeamName(),
 			Email:          th.GenerateTestEmail(),
 			Type:           model.TEAM_OPEN,
-			AllowedDomains: "simulator.amazonses.com",
+			AllowedDomains: "simulator.amazonses.com,dockerhost",
 		}
 
 		rteam, resp := th.SystemAdminClient.CreateTeam(team)
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 }
@@ -183,7 +179,7 @@ func TestGetTeamSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -197,8 +193,6 @@ func TestGetTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email != "" {
 			t.Fatal("should've sanitized email")
-		} else if rteam.AllowedDomains != "" {
-			t.Fatal("should've sanitized allowed domains")
 		}
 	})
 
@@ -207,8 +201,6 @@ func TestGetTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 
@@ -217,8 +209,6 @@ func TestGetTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 }
@@ -364,7 +354,7 @@ func TestUpdateTeamSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -375,8 +365,6 @@ func TestUpdateTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email for admin")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 
@@ -385,8 +373,6 @@ func TestUpdateTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email for admin")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 }
@@ -463,7 +449,7 @@ func TestPatchTeamSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -474,8 +460,6 @@ func TestPatchTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email for admin")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 
@@ -484,8 +468,6 @@ func TestPatchTeamSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email for admin")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 }
@@ -655,7 +637,7 @@ func TestGetAllTeamsSanitization(t *testing.T) {
 		Name:            GenerateTestTeamName(),
 		Email:           th.GenerateTestEmail(),
 		Type:            model.TEAM_OPEN,
-		AllowedDomains:  "simulator.amazonses.com",
+		AllowedDomains:  "simulator.amazonses.com,dockerhost",
 		AllowOpenInvite: true,
 	})
 	CheckNoError(t, resp)
@@ -664,7 +646,7 @@ func TestGetAllTeamsSanitization(t *testing.T) {
 		Name:            GenerateTestTeamName(),
 		Email:           th.GenerateTestEmail(),
 		Type:            model.TEAM_OPEN,
-		AllowedDomains:  "simulator.amazonses.com",
+		AllowedDomains:  "simulator.amazonses.com,dockerhost",
 		AllowOpenInvite: true,
 	})
 	CheckNoError(t, resp)
@@ -682,15 +664,11 @@ func TestGetAllTeamsSanitization(t *testing.T) {
 				teamFound = true
 				if rteam.Email == "" {
 					t.Fatal("should not have sanitized email for team admin")
-				} else if rteam.AllowedDomains == "" {
-					t.Fatal("should not have sanitized allowed domains for team admin")
 				}
 			} else if rteam.Id == team2.Id {
 				team2Found = true
 				if rteam.Email != "" {
 					t.Fatal("should've sanitized email for non-admin")
-				} else if rteam.AllowedDomains != "" {
-					t.Fatal("should've sanitized allowed domains for non-admin")
 				}
 			}
 		}
@@ -710,8 +688,6 @@ func TestGetAllTeamsSanitization(t *testing.T) {
 
 			if rteam.Email == "" {
 				t.Fatal("should not have sanitized email")
-			} else if rteam.AllowedDomains == "" {
-				t.Fatal("should not have sanitized allowed domains")
 			}
 		}
 	})
@@ -773,7 +749,7 @@ func TestGetTeamByNameSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -787,8 +763,6 @@ func TestGetTeamByNameSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email != "" {
 			t.Fatal("should've sanitized email")
-		} else if rteam.AllowedDomains != "" {
-			t.Fatal("should've sanitized allowed domains")
 		}
 	})
 
@@ -797,8 +771,6 @@ func TestGetTeamByNameSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 
@@ -807,8 +779,6 @@ func TestGetTeamByNameSanitization(t *testing.T) {
 		CheckNoError(t, resp)
 		if rteam.Email == "" {
 			t.Fatal("should not have sanitized email")
-		} else if rteam.AllowedDomains == "" {
-			t.Fatal("should not have sanitized allowed domains")
 		}
 	})
 }
@@ -904,7 +874,7 @@ func TestSearchAllTeamsSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 	team2, resp := th.Client.CreateTeam(&model.Team{
@@ -912,7 +882,7 @@ func TestSearchAllTeamsSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -955,8 +925,6 @@ func TestSearchAllTeamsSanitization(t *testing.T) {
 			if rteam.Id == team.Id || rteam.Id == team2.Id || rteam.Id == th.BasicTeam.Id {
 				if rteam.Email == "" {
 					t.Fatal("should not have sanitized email")
-				} else if rteam.AllowedDomains == "" {
-					t.Fatal("should not have sanitized allowed domains")
 				}
 			}
 		}
@@ -968,8 +936,6 @@ func TestSearchAllTeamsSanitization(t *testing.T) {
 		for _, rteam := range rteams {
 			if rteam.Email == "" {
 				t.Fatal("should not have sanitized email")
-			} else if rteam.AllowedDomains == "" {
-				t.Fatal("should not have sanitized allowed domains")
 			}
 		}
 	})
@@ -1026,7 +992,7 @@ func TestGetTeamsForUserSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 	team2, resp := th.Client.CreateTeam(&model.Team{
@@ -1034,7 +1000,7 @@ func TestGetTeamsForUserSanitization(t *testing.T) {
 		Name:           GenerateTestTeamName(),
 		Email:          th.GenerateTestEmail(),
 		Type:           model.TEAM_OPEN,
-		AllowedDomains: "simulator.amazonses.com",
+		AllowedDomains: "simulator.amazonses.com,dockerhost",
 	})
 	CheckNoError(t, resp)
 
@@ -1054,8 +1020,6 @@ func TestGetTeamsForUserSanitization(t *testing.T) {
 
 			if rteam.Email != "" {
 				t.Fatal("should've sanitized email")
-			} else if rteam.AllowedDomains != "" {
-				t.Fatal("should've sanitized allowed domains")
 			}
 		}
 	})
@@ -1070,8 +1034,6 @@ func TestGetTeamsForUserSanitization(t *testing.T) {
 
 			if rteam.Email == "" {
 				t.Fatal("should not have sanitized email")
-			} else if rteam.AllowedDomains == "" {
-				t.Fatal("should not have sanitized allowed domains")
 			}
 		}
 	})
@@ -1086,8 +1048,6 @@ func TestGetTeamsForUserSanitization(t *testing.T) {
 
 			if rteam.Email == "" {
 				t.Fatal("should not have sanitized email")
-			} else if rteam.AllowedDomains == "" {
-				t.Fatal("should not have sanitized allowed domains")
 			}
 		}
 	})
@@ -1993,17 +1953,48 @@ func TestInviteUsersToTeam(t *testing.T) {
 		}
 	}
 
-	th.App.UpdateConfig(func(cfg *model.Config) { cfg.TeamSettings.RestrictCreationToDomains = "@example.com" })
+	th.App.UpdateConfig(func(cfg *model.Config) { cfg.TeamSettings.RestrictCreationToDomains = "@global.com,@common.com" })
 
-	err := th.App.InviteNewUsersToTeam(emailList, th.BasicTeam.Id, th.BasicUser.Id)
+	t.Run("restricted domains", func(t *testing.T) {
+		err := th.App.InviteNewUsersToTeam(emailList, th.BasicTeam.Id, th.BasicUser.Id)
 
-	if err == nil {
-		t.Fatal("Adding users with non-restricted domains was allowed")
-	}
-	if err.Where != "InviteNewUsersToTeam" || err.Id != "api.team.invite_members.invalid_email.app_error" {
-		t.Log(err)
-		t.Fatal("Got wrong error message!")
-	}
+		if err == nil {
+			t.Fatal("Adding users with non-restricted domains was allowed")
+		}
+		if err.Where != "InviteNewUsersToTeam" || err.Id != "api.team.invite_members.invalid_email.app_error" {
+			t.Log(err)
+			t.Fatal("Got wrong error message!")
+		}
+	})
+
+	t.Run("override restricted domains", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "invalid.com,common.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err == nil {
+			t.Fatal("Should not update the team")
+		}
+
+		th.BasicTeam.AllowedDomains = "common.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		if err := th.App.InviteNewUsersToTeam([]string{"test@global.com"}, th.BasicTeam.Id, th.BasicUser.Id); err == nil || err.Where != "InviteNewUsersToTeam" {
+			t.Log(err)
+			t.Fatal("Per team restriction should take precedence over the global restriction")
+		}
+
+		if err := th.App.InviteNewUsersToTeam([]string{"test@common.com"}, th.BasicTeam.Id, th.BasicUser.Id); err != nil {
+			t.Log(err)
+			t.Fatal("Failed to invite user which was common between team and global domain restriction")
+		}
+
+		if err := th.App.InviteNewUsersToTeam([]string{"test@invalid.com"}, th.BasicTeam.Id, th.BasicUser.Id); err == nil {
+			t.Log(err)
+			t.Fatal("Should not invite user")
+		}
+
+	})
 }
 
 func TestGetTeamInviteInfo(t *testing.T) {

app/team.go

@@ -44,7 +44,7 @@ func (a *App) CreateTeamWithUser(team *model.Team, userId string) (*model.Team,
 		team.Email = user.Email
 	}
 
-	if !a.isTeamEmailAllowed(user) {
+	if !a.isTeamEmailAllowed(user, team) {
 		return nil, model.NewAppError("isTeamEmailAllowed", "api.team.is_team_creation_allowed.domain.app_error", nil, "", http.StatusBadRequest)
 	}
 
@@ -60,35 +60,43 @@ func (a *App) CreateTeamWithUser(team *model.Team, userId string) (*model.Team,
 	return rteam, nil
 }
 
-func (a *App) isTeamEmailAddressAllowed(email string) bool {
-	email = strings.ToLower(email)
+func (a *App) normalizeDomains(domains string) []string {
 	// commas and @ signs are optional
 	// can be in the form of "@corp.mattermost.com, mattermost.com mattermost.org" -> corp.mattermost.com mattermost.com mattermost.org
-	domains := strings.Fields(strings.TrimSpace(strings.ToLower(strings.Replace(strings.Replace(a.Config().TeamSettings.RestrictCreationToDomains, "@", " ", -1), ",", " ", -1))))
+	return strings.Fields(strings.TrimSpace(strings.ToLower(strings.Replace(strings.Replace(domains, "@", " ", -1), ",", " ", -1))))
+}
 
-	matched := false
-	for _, d := range domains {
-		if strings.HasSuffix(email, "@"+d) {
-			matched = true
-			break
+func (a *App) isTeamEmailAddressAllowed(email string, allowedDomains string) bool {
+	email = strings.ToLower(email)
+	// First check per team allowedDomains, then app wide restrictions
+	for _, restriction := range []string{allowedDomains, a.Config().TeamSettings.RestrictCreationToDomains} {
+		domains := a.normalizeDomains(restriction)
+		if len(domains) <= 0 {
+			continue
+		}
+		matched := false
+		for _, d := range domains {
+			if strings.HasSuffix(email, "@"+d) {
+				matched = true
+				break
+			}
+		}
+		if !matched {
+			return false
 		}
-	}
-
-	if len(a.Config().TeamSettings.RestrictCreationToDomains) > 0 && !matched {
-		return false
 	}
 
 	return true
 }
 
-func (a *App) isTeamEmailAllowed(user *model.User) bool {
+func (a *App) isTeamEmailAllowed(user *model.User, team *model.Team) bool {
 	email := strings.ToLower(user.Email)
 
 	if len(user.AuthService) > 0 && len(*user.AuthData) > 0 {
 		return true
 	}
 
-	return a.isTeamEmailAddressAllowed(email)
+	return a.isTeamEmailAddressAllowed(email, team.AllowedDomains)
 }
 
 func (a *App) UpdateTeam(team *model.Team) (*model.Team, *model.AppError) {
@@ -98,6 +106,23 @@ func (a *App) UpdateTeam(team *model.Team) (*model.Team, *model.AppError) {
 		return nil, err
 	}
 
+	validDomains := a.normalizeDomains(a.Config().TeamSettings.RestrictCreationToDomains)
+	if len(validDomains) > 0 {
+		for _, domain := range a.normalizeDomains(team.AllowedDomains) {
+			matched := false
+			for _, d := range validDomains {
+				if domain == d {
+					matched = true
+					break
+				}
+			}
+			if !matched {
+				err := model.NewAppError("UpdateTeam", "api.team.update_restricted_domains.mismatch.app_error", map[string]interface{}{"Domain": domain}, "", http.StatusBadRequest)
+				return nil, err
+			}
+		}
+	}
+
 	oldTeam.DisplayName = team.DisplayName
 	oldTeam.Description = team.Description
 	oldTeam.InviteId = team.InviteId
@@ -430,6 +455,9 @@ func (a *App) joinUserToTeam(team *model.Team, user *model.User) (*model.TeamMem
 }
 
 func (a *App) JoinUserToTeam(team *model.Team, user *model.User, userRequestorId string) *model.AppError {
+	if !a.isTeamEmailAllowed(user, team) {
+		return model.NewAppError("JoinUserToTeam", "api.team.join_user_to_team.allowed_domains.app_error", nil, "", http.StatusBadRequest)
+	}
 	tm, alreadyAdded, err := a.joinUserToTeam(team, user)
 	if err != nil {
 		return err
@@ -843,20 +871,6 @@ func (a *App) InviteNewUsersToTeam(emailList []string, teamId, senderId string)
 		return err
 	}
 
-	var invalidEmailList []string
-
-	for _, email := range emailList {
-		if !a.isTeamEmailAddressAllowed(email) {
-			invalidEmailList = append(invalidEmailList, email)
-		}
-	}
-
-	if len(invalidEmailList) > 0 {
-		s := strings.Join(invalidEmailList, ", ")
-		err := model.NewAppError("InviteNewUsersToTeam", "api.team.invite_members.invalid_email.app_error", map[string]interface{}{"Addresses": s}, "", http.StatusBadRequest)
-		return err
-	}
-
 	tchan := a.Srv.Store.Team().Get(teamId)
 	uchan := a.Srv.Store.User().Get(senderId)
 
@@ -874,6 +888,20 @@ func (a *App) InviteNewUsersToTeam(emailList []string, teamId, senderId string)
 		user = result.Data.(*model.User)
 	}
 
+	var invalidEmailList []string
+
+	for _, email := range emailList {
+		if !a.isTeamEmailAddressAllowed(email, team.AllowedDomains) {
+			invalidEmailList = append(invalidEmailList, email)
+		}
+	}
+
+	if len(invalidEmailList) > 0 {
+		s := strings.Join(invalidEmailList, ", ")
+		err := model.NewAppError("InviteNewUsersToTeam", "api.team.invite_members.invalid_email.app_error", map[string]interface{}{"Addresses": s}, "", http.StatusBadRequest)
+		return err
+	}
+
 	nameFormat := *a.Config().TeamSettings.TeammateNameDisplay
 	a.SendInviteEmails(team, user.GetDisplayName(nameFormat), user.Id, emailList, a.GetSiteURL())
 

app/team_test.go

@@ -73,13 +73,99 @@ func TestAddUserToTeam(t *testing.T) {
 	th := Setup().InitBasic()
 	defer th.TearDown()
 
-	user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
-	ruser, _ := th.App.CreateUser(&user)
+	t.Run("add user", func(t *testing.T) {
+		user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
 
-	if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser.Id, ""); err != nil {
-		t.Log(err)
-		t.Fatal("Should add user to the team")
-	}
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser.Id, ""); err != nil {
+			t.Log(err)
+			t.Fatal("Should add user to the team")
+		}
+	})
+
+	t.Run("allow user by domain", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "example.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
+
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser.Id, ""); err != nil {
+			t.Log(err)
+			t.Fatal("Should have allowed whitelisted user")
+		}
+	})
+
+	t.Run("block user by domain", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "example.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user := model.User{Email: strings.ToLower(model.NewId()) + "test@invalid.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
+
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser.Id, ""); err == nil || err.Where != "JoinUserToTeam" {
+			t.Log(err)
+			t.Fatal("Should not add restricted user")
+		}
+	})
+
+	t.Run("block user with subdomain", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "example.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user := model.User{Email: strings.ToLower(model.NewId()) + "test@invalid.example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
+
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser.Id, ""); err == nil || err.Where != "JoinUserToTeam" {
+			t.Log(err)
+			t.Fatal("Should not add restricted user")
+		}
+	})
+
+	t.Run("allow users by multiple domains", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "foo.com, bar.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user1 := model.User{Email: strings.ToLower(model.NewId()) + "success+test@foo.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser1, _ := th.App.CreateUser(&user1)
+		user2 := model.User{Email: strings.ToLower(model.NewId()) + "success+test@bar.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser2, _ := th.App.CreateUser(&user2)
+		user3 := model.User{Email: strings.ToLower(model.NewId()) + "success+test@invalid.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser3, _ := th.App.CreateUser(&user3)
+		defer th.App.PermanentDeleteUser(&user1)
+		defer th.App.PermanentDeleteUser(&user2)
+		defer th.App.PermanentDeleteUser(&user3)
+
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser1.Id, ""); err != nil {
+			t.Log(err)
+			t.Fatal("Should have allowed whitelisted user1")
+		}
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser2.Id, ""); err != nil {
+			t.Log(err)
+			t.Fatal("Should have allowed whitelisted user2")
+		}
+		if _, err := th.App.AddUserToTeam(th.BasicTeam.Id, ruser3.Id, ""); err == nil || err.Where != "JoinUserToTeam" {
+			t.Log(err)
+			t.Fatal("Should not have allowed restricted user3")
+		}
+
+	})
 }
 
 func TestAddUserToTeamByToken(t *testing.T) {
@@ -158,19 +244,62 @@ func TestAddUserToTeamByToken(t *testing.T) {
 			t.Fatal("The token must be deleted after be used")
 		}
 	})
+
+	t.Run("block user", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "example.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user := model.User{Email: strings.ToLower(model.NewId()) + "test@invalid.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
+
+		token := model.NewToken(
+			TOKEN_TYPE_TEAM_INVITATION,
+			model.MapToJson(map[string]string{"teamId": th.BasicTeam.Id}),
+		)
+		<-th.App.Srv.Store.Token().Save(token)
+
+		if _, err := th.App.AddUserToTeamByToken(ruser.Id, token.Token); err == nil || err.Where != "JoinUserToTeam" {
+			t.Log(err)
+			t.Fatal("Should not add restricted user")
+		}
+	})
 }
 
 func TestAddUserToTeamByTeamId(t *testing.T) {
 	th := Setup().InitBasic()
 	defer th.TearDown()
 
-	user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
-	ruser, _ := th.App.CreateUser(&user)
+	t.Run("add user", func(t *testing.T) {
+		user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@example.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+
+		if err := th.App.AddUserToTeamByTeamId(th.BasicTeam.Id, ruser); err != nil {
+			t.Log(err)
+			t.Fatal("Should add user to the team")
+		}
+	})
+
+	t.Run("block user", func(t *testing.T) {
+		th.BasicTeam.AllowedDomains = "example.com"
+		if _, err := th.App.UpdateTeam(th.BasicTeam); err != nil {
+			t.Log(err)
+			t.Fatal("Should update the team")
+		}
+
+		user := model.User{Email: strings.ToLower(model.NewId()) + "test@invalid.com", Nickname: "Darth Vader", Username: "vader" + model.NewId(), Password: "passwd1", AuthService: ""}
+		ruser, _ := th.App.CreateUser(&user)
+		defer th.App.PermanentDeleteUser(&user)
+
+		if err := th.App.AddUserToTeamByTeamId(th.BasicTeam.Id, ruser); err == nil || err.Where != "JoinUserToTeam" {
+			t.Log(err)
+			t.Fatal("Should not add restricted user")
+		}
+	})
 
-	if err := th.App.AddUserToTeamByTeamId(th.BasicTeam.Id, ruser); err != nil {
-		t.Log(err)
-		t.Fatal("Should add user to the team")
-	}
 }
 
 func TestPermanentDeleteTeam(t *testing.T) {
@@ -264,7 +393,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email != "" && sanitized.AllowedDomains != "" {
+		if sanitized.Email != "" {
 			t.Fatal("should've sanitized team")
 		}
 	})
@@ -283,7 +412,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email != "" && sanitized.AllowedDomains != "" {
+		if sanitized.Email != "" {
 			t.Fatal("should've sanitized team")
 		}
 	})
@@ -302,7 +431,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email == "" && sanitized.AllowedDomains == "" {
+		if sanitized.Email == "" {
 			t.Fatal("shouldn't have sanitized team")
 		}
 	})
@@ -321,7 +450,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email != "" && sanitized.AllowedDomains != "" {
+		if sanitized.Email != "" {
 			t.Fatal("should've sanitized team")
 		}
 	})
@@ -340,7 +469,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email == "" && sanitized.AllowedDomains == "" {
+		if sanitized.Email == "" {
 			t.Fatal("shouldn't have sanitized team")
 		}
 	})
@@ -359,7 +488,7 @@ func TestSanitizeTeam(t *testing.T) {
 		}
 
 		sanitized := th.App.SanitizeTeam(session, copyTeam())
-		if sanitized.Email == "" && sanitized.AllowedDomains == "" {
+		if sanitized.Email == "" {
 			t.Fatal("shouldn't have sanitized team")
 		}
 	})
@@ -402,11 +531,11 @@ func TestSanitizeTeams(t *testing.T) {
 
 		sanitized := th.App.SanitizeTeams(session, teams)
 
-		if sanitized[0].Email != "" && sanitized[0].AllowedDomains != "" {
+		if sanitized[0].Email != "" {
 			t.Fatal("should've sanitized first team")
 		}
 
-		if sanitized[1].Email == "" && sanitized[1].AllowedDomains == "" {
+		if sanitized[1].Email == "" {
 			t.Fatal("shouldn't have sanitized second team")
 		}
 	})
@@ -439,11 +568,11 @@ func TestSanitizeTeams(t *testing.T) {
 
 		sanitized := th.App.SanitizeTeams(session, teams)
 
-		if sanitized[0].Email == "" && sanitized[0].AllowedDomains == "" {
+		if sanitized[0].Email == "" {
 			t.Fatal("shouldn't have sanitized first team")
 		}
 
-		if sanitized[1].Email == "" && sanitized[1].AllowedDomains == "" {
+		if sanitized[1].Email == "" {
 			t.Fatal("shouldn't have sanitized second team")
 		}
 	})

i18n/en.json

@@ -1654,6 +1654,10 @@
     "id": "api.team.join_team.post_and_forget",
     "translation": "%v joined the team."
   },
+  {
+    "id": "api.team.join_user_to_team.allowed_domains.app_error",
+    "translation": "Email must be from a specific domain (e.g. @example.com). Please ask your team or system administrator for details."
+  },
   {
     "id": "api.team.leave.left",
     "translation": "%v left the team."
@@ -1730,6 +1734,10 @@
     "id": "api.team.update_member_roles.not_a_member",
     "translation": "Specified user is not a member of specified team."
   },
+  {
+    "id": "api.team.update_restricted_domains.mismatch.app_error",
+    "translation": "Restricting team to {{ .Domain }} is not allowed by the system config. Please contact your system administrator."
+  },
   {
     "id": "api.team.update_team_scheme.license.error",
     "translation": "Your license does not support updating a team's scheme"

model/team.go

@@ -47,6 +47,7 @@ type TeamPatch struct {
 	DisplayName     *string `json:"display_name"`
 	Description     *string `json:"description"`
 	CompanyName     *string `json:"company_name"`
+	AllowedDomains  *string `json:"allowed_domains"`
 	InviteId        *string `json:"invite_id"`
 	AllowOpenInvite *bool   `json:"allow_open_invite"`
 }
@@ -241,7 +242,6 @@ func CleanTeamName(s string) string {
 
 func (o *Team) Sanitize() {
 	o.Email = ""
-	o.AllowedDomains = ""
 }
 
 func (t *Team) Patch(patch *TeamPatch) {
@@ -257,6 +257,10 @@ func (t *Team) Patch(patch *TeamPatch) {
 		t.CompanyName = *patch.CompanyName
 	}
 
+	if patch.AllowedDomains != nil {
+		t.AllowedDomains = *patch.AllowedDomains
+	}
+
 	if patch.InviteId != nil {
 		t.InviteId = *patch.InviteId
 	}