Merge branch '19146-can-write-manage'
[arvados.git] / services / api / app / models / user.rb
index 6f2f92b93d43f43101e0a80ef113913f467ef5b1..52d36ac57735f0c16d4b0ed6271a50681e08e05b 100644 (file)
@@ -3,13 +3,13 @@
 # SPDX-License-Identifier: AGPL-3.0
 
 require 'can_be_an_owner'
-require 'refresh_permission_view'
 
 class User < ArvadosModel
   include HasUuid
   include KindAndEtag
   include CommonApiTemplate
   include CanBeAnOwner
+  extend CurrentApiClient
 
   serialize :prefs, Hash
   has_many :api_client_authorizations
@@ -20,31 +20,40 @@ class User < ArvadosModel
             },
             uniqueness: true,
             allow_nil: true)
+  validate :must_unsetup_to_deactivate
+  validate :identity_url_nil_if_empty
   before_update :prevent_privilege_escalation
   before_update :prevent_inactive_admin
-  before_update :verify_repositories_empty, :if => Proc.new { |user|
-    user.username.nil? and user.username_changed?
+  before_update :verify_repositories_empty, :if => Proc.new {
+    username.nil? and username_changed?
   }
-  before_update :setup_on_activate
+  after_update :setup_on_activate
+
   before_create :check_auto_admin
-  before_create :set_initial_username, :if => Proc.new { |user|
-    user.username.nil? and user.email
+  before_create :set_initial_username, :if => Proc.new {
+    username.nil? and email
   }
+  after_create :after_ownership_change
   after_create :setup_on_activate
   after_create :add_system_group_permission_link
-  after_create :invalidate_permissions_cache
-  after_create :auto_setup_new_user, :if => Proc.new { |user|
+  after_create :auto_setup_new_user, :if => Proc.new {
     Rails.configuration.Users.AutoSetupNewUsers and
-    (user.uuid != system_user_uuid) and
-    (user.uuid != anonymous_user_uuid)
+    (uuid != system_user_uuid) and
+    (uuid != anonymous_user_uuid) and
+    (uuid[0..4] == Rails.configuration.ClusterID)
   }
   after_create :send_admin_notifications
+
+  before_update :before_ownership_change
+  after_update :after_ownership_change
   after_update :send_profile_created_notification
-  after_update :sync_repository_names, :if => Proc.new { |user|
-    (user.uuid != system_user_uuid) and
-    user.username_changed? and
-    (not user.username_was.nil?)
+  after_update :sync_repository_names, :if => Proc.new {
+    (uuid != system_user_uuid) and
+    saved_change_to_username? and
+    (not username_before_last_save.nil?)
   }
+  before_destroy :clear_permissions
+  after_destroy :remove_self_from_permissions
 
   has_many :authorized_keys, :foreign_key => :authorized_user_uuid, :primary_key => :uuid
   has_many :repositories, foreign_key: :owner_uuid, primary_key: :uuid
@@ -63,6 +72,8 @@ class User < ArvadosModel
     t.add :is_invited
     t.add :prefs
     t.add :writable_by
+    t.add :can_write
+    t.add :can_manage
   end
 
   ALL_PERMISSIONS = {read: true, write: true, manage: true}
@@ -75,6 +86,13 @@ class User < ArvadosModel
      {read: true, write: true},
      {read: true, write: true, manage: true}]
 
+  VAL_FOR_PERM =
+    {:read => 1,
+     :write => 2,
+     :unfreeze => 3,
+     :manage => 3}
+
+
   def full_name
     "#{first_name} #{last_name}".strip
   end
@@ -86,7 +104,7 @@ class User < ArvadosModel
   end
 
   def groups_i_can(verb)
-    my_groups = self.group_permissions.select { |uuid, mask| mask[verb] }.keys
+    my_groups = self.group_permissions(VAL_FOR_PERM[verb]).keys
     if verb == :read
       my_groups << anonymous_group_uuid
     end
@@ -94,7 +112,6 @@ class User < ArvadosModel
   end
 
   def can?(actions)
-    return true if is_admin
     actions.each do |action, target|
       unless target.nil?
         if target.respond_to? :uuid
@@ -105,60 +122,97 @@ class User < ArvadosModel
         end
       end
       next if target_uuid == self.uuid
-      next if (group_permissions[target_uuid] and
-               group_permissions[target_uuid][action])
-      if target.respond_to? :owner_uuid
-        next if target.owner_uuid == self.uuid
-        next if (group_permissions[target.owner_uuid] and
-                 group_permissions[target.owner_uuid][action])
+
+      if action == :write && target && !target.new_record? &&
+         target.respond_to?(:frozen_by_uuid) &&
+         target.frozen_by_uuid_was
+        # Just an optimization to skip the PERMISSION_VIEW and
+        # FrozenGroup queries below
+        return false
+      end
+
+      target_owner_uuid = target.owner_uuid if target.respond_to? :owner_uuid
+
+      user_uuids_subquery = USER_UUIDS_SUBQUERY_TEMPLATE % {user: "$1", perm_level: "$3"}
+
+      if !is_admin && !ActiveRecord::Base.connection.
+        exec_query(%{
+SELECT 1 FROM #{PERMISSION_VIEW}
+  WHERE user_uuid in (#{user_uuids_subquery}) and
+        ((target_uuid = $2 and perm_level >= $3)
+         or (target_uuid = $4 and perm_level >= $3 and traverse_owned))
+},
+                  # "name" arg is a query label that appears in logs:
+                   "user_can_query",
+                   [[nil, self.uuid],
+                    [nil, target_uuid],
+                    [nil, VAL_FOR_PERM[action]],
+                    [nil, target_owner_uuid]]
+                  ).any?
+        return false
       end
-      sufficient_perms = case action
-                         when :manage
-                           ['can_manage']
-                         when :write
-                           ['can_manage', 'can_write']
-                         when :read
-                           ['can_manage', 'can_write', 'can_read']
-                         else
-                           # (Skip this kind of permission opportunity
-                           # if action is an unknown permission type)
-                         end
-      if sufficient_perms
-        # Check permission links with head_uuid pointing directly at
-        # the target object. If target is a Group, this is redundant
-        # and will fail except [a] if permission caching is broken or
-        # [b] during a race condition, where a permission link has
-        # *just* been added.
-        if Link.where(link_class: 'permission',
-                      name: sufficient_perms,
-                      tail_uuid: groups_i_can(action) + [self.uuid],
-                      head_uuid: target_uuid).any?
-          next
+
+      if action == :write
+        if FrozenGroup.where(uuid: [target_uuid, target_owner_uuid]).any?
+          # self or parent is frozen
+          return false
+        end
+      elsif action == :unfreeze
+        # "unfreeze" permission means "can write, but only if
+        # explicitly un-freezing at the same time" (see
+        # ArvadosModel#ensure_owner_uuid_is_permitted). If the
+        # permission query above passed the permission level of
+        # :unfreeze (which is the same as :manage), and the parent
+        # isn't also frozen, then un-freeze is allowed.
+        if FrozenGroup.where(uuid: target_owner_uuid).any?
+          return false
         end
       end
-      return false
     end
     true
   end
 
-  def self.invalidate_permissions_cache(async=false)
-    refresh_permission_view(async)
+  def before_ownership_change
+    if owner_uuid_changed? and !self.owner_uuid_was.nil?
+      MaterializedPermission.where(user_uuid: owner_uuid_was, target_uuid: uuid).delete_all
+      update_permissions self.owner_uuid_was, self.uuid, REVOKE_PERM
+    end
+  end
+
+  def after_ownership_change
+    if saved_change_to_owner_uuid?
+      update_permissions self.owner_uuid, self.uuid, CAN_MANAGE_PERM
+    end
+  end
+
+  def clear_permissions
+    MaterializedPermission.where("user_uuid = ? and target_uuid != ?", uuid, uuid).delete_all
   end
 
-  def invalidate_permissions_cache
-    User.invalidate_permissions_cache
+  def forget_cached_group_perms
+    @group_perms = nil
+  end
+
+  def remove_self_from_permissions
+    MaterializedPermission.where("target_uuid = ?", uuid).delete_all
+    check_permissions_against_full_refresh
   end
 
   # Return a hash of {user_uuid: group_perms}
+  #
+  # note: this does not account for permissions that a user gains by
+  # having can_manage on another user.
   def self.all_group_permissions
     all_perms = {}
     ActiveRecord::Base.connection.
-      exec_query("SELECT user_uuid, target_owner_uuid, perm_level, trashed
+      exec_query(%{
+SELECT user_uuid, target_uuid, perm_level
                   FROM #{PERMISSION_VIEW}
-                  WHERE target_owner_uuid IS NOT NULL",
+                  WHERE traverse_owned
+},
                   # "name" arg is a query label that appears in logs:
-                  "all_group_permissions",
-                  ).rows.each do |user_uuid, group_uuid, max_p_val, trashed|
+                 "all_group_permissions").
+      rows.each do |user_uuid, group_uuid, max_p_val|
       all_perms[user_uuid] ||= {}
       all_perms[user_uuid][group_uuid] = PERMS_FOR_VAL[max_p_val.to_i]
     end
@@ -168,36 +222,89 @@ class User < ArvadosModel
   # Return a hash of {group_uuid: perm_hash} where perm_hash[:read]
   # and perm_hash[:write] are true if this user can read and write
   # objects owned by group_uuid.
-  def group_permissions
-    group_perms = {self.uuid => {:read => true, :write => true, :manage => true}}
-    ActiveRecord::Base.connection.
-      exec_query("SELECT target_owner_uuid, perm_level, trashed
-                  FROM #{PERMISSION_VIEW}
-                  WHERE user_uuid = $1
-                  AND target_owner_uuid IS NOT NULL",
-                  # "name" arg is a query label that appears in logs:
-                  "group_permissions for #{uuid}",
-                  # "binds" arg is an array of [col_id, value] for '$1' vars:
-                  [[nil, uuid]],
-                ).rows.each do |group_uuid, max_p_val, trashed|
-      group_perms[group_uuid] = PERMS_FOR_VAL[max_p_val.to_i]
+  def group_permissions(level=1)
+    @group_perms ||= {}
+    if @group_perms.empty?
+      user_uuids_subquery = USER_UUIDS_SUBQUERY_TEMPLATE % {user: "$1", perm_level: 1}
+
+      ActiveRecord::Base.connection.
+        exec_query(%{
+SELECT target_uuid, perm_level
+  FROM #{PERMISSION_VIEW}
+  WHERE user_uuid in (#{user_uuids_subquery}) and perm_level >= 1
+},
+                   # "name" arg is a query label that appears in logs:
+                   "User.group_permissions",
+                   # "binds" arg is an array of [col_id, value] for '$1' vars:
+                   [[nil, uuid]]).
+        rows.each do |group_uuid, max_p_val|
+        @group_perms[group_uuid] = PERMS_FOR_VAL[max_p_val.to_i]
+      end
+    end
+
+    case level
+    when 1
+      @group_perms
+    when 2
+      @group_perms.select {|k,v| v[:write] }
+    when 3
+      @group_perms.select {|k,v| v[:manage] }
+    else
+      raise "level must be 1, 2 or 3"
     end
-    group_perms
   end
 
   # create links
-  def setup(openid_prefix:, repo_name: nil, vm_uuid: nil)
-    oid_login_perm = create_oid_login_perm openid_prefix
-    repo_perm = create_user_repo_link repo_name
-    vm_login_perm = create_vm_login_permission_link(vm_uuid, username) if vm_uuid
-    group_perm = create_user_group_link
+  def setup(repo_name: nil, vm_uuid: nil, send_notification_email: nil)
+    newly_invited = Link.where(tail_uuid: self.uuid,
+                              head_uuid: all_users_group_uuid,
+                              link_class: 'permission',
+                              name: 'can_read').empty?
+
+    # Add can_read link from this user to "all users" which makes this
+    # user "invited", and (depending on config) a link in the opposite
+    # direction which makes this user visible to other users.
+    group_perms = add_to_all_users_group
+
+    # Add git repo
+    repo_perm = if (!repo_name.nil? || Rails.configuration.Users.AutoSetupNewUsersWithRepository) and !username.nil?
+                  repo_name ||= "#{username}/#{username}"
+                  create_user_repo_link repo_name
+                end
+
+    # Add virtual machine
+    if vm_uuid.nil? and !Rails.configuration.Users.AutoSetupNewUsersWithVmUUID.empty?
+      vm_uuid = Rails.configuration.Users.AutoSetupNewUsersWithVmUUID
+    end
+
+    vm_login_perm = if vm_uuid && username
+                      create_vm_login_permission_link(vm_uuid, username)
+                    end
+
+    # Send welcome email
+    if send_notification_email.nil?
+      send_notification_email = Rails.configuration.Mail.SendUserSetupNotificationEmail
+    end
+
+    if newly_invited and send_notification_email and !Rails.configuration.Users.UserSetupMailText.empty?
+      begin
+        UserNotifier.account_is_setup(self).deliver_now
+      rescue => e
+        logger.warn "Failed to send email to #{self.email}: #{e}"
+      end
+    end
+
+    forget_cached_group_perms
 
-    return [oid_login_perm, repo_perm, vm_login_perm, group_perm, self].compact
+    return [repo_perm, vm_login_perm, *group_perms, self].compact
   end
 
   # delete user signatures, login, repo, and vm perms, and mark as inactive
   def unsetup
     # delete oid_login_perms for this user
+    #
+    # note: these permission links are obsolete, they have no effect
+    # on anything and they are not created for new users.
     Link.where(tail_uuid: self.email,
                      link_class: 'permission',
                      name: 'can_login').destroy_all
@@ -213,11 +320,8 @@ class User < ArvadosModel
                      name: 'can_login').destroy_all
 
     # delete "All users" group read permissions for this user
-    group = Group.where(name: 'All users').select do |g|
-      g[:uuid].match(/-f+$/)
-    end.first
     Link.where(tail_uuid: self.uuid,
-                     head_uuid: group[:uuid],
+                     head_uuid: all_users_group_uuid,
                      link_class: 'permission',
                      name: 'can_read').destroy_all
 
@@ -225,14 +329,55 @@ class User < ArvadosModel
     Link.where(link_class: 'signature',
                      tail_uuid: self.uuid).destroy_all
 
+    # delete tokens for this user
+    ApiClientAuthorization.where(user_id: self.id).destroy_all
+    # delete ssh keys for this user
+    AuthorizedKey.where(owner_uuid: self.uuid).destroy_all
+    AuthorizedKey.where(authorized_user_uuid: self.uuid).destroy_all
+
     # delete user preferences (including profile)
     self.prefs = {}
 
     # mark the user as inactive
+    self.is_admin = false  # can't be admin and inactive
     self.is_active = false
+    forget_cached_group_perms
     self.save!
   end
 
+  def must_unsetup_to_deactivate
+    if !self.new_record? &&
+       self.uuid[0..4] == Rails.configuration.Login.LoginCluster &&
+       self.uuid[0..4] != Rails.configuration.ClusterID
+      # OK to update our local record to whatever the LoginCluster
+      # reports, because self-activate is not allowed.
+      return
+    elsif self.is_active_changed? &&
+       self.is_active_was &&
+       !self.is_active
+
+      # When a user is set up, they are added to the "All users"
+      # group.  A user that is part of the "All users" group is
+      # allowed to self-activate.
+      #
+      # It doesn't make sense to deactivate a user (set is_active =
+      # false) without first removing them from the "All users" group,
+      # because they would be able to immediately reactivate
+      # themselves.
+      #
+      # The 'unsetup' method removes the user from the "All users"
+      # group (and also sets is_active = false) so send a message
+      # explaining the correct way to deactivate a user.
+      #
+      if Link.where(tail_uuid: self.uuid,
+                    head_uuid: all_users_group_uuid,
+                    link_class: 'permission',
+                    name: 'can_read').any?
+        errors.add :is_active, "cannot be set to false directly, use the 'Deactivate' button on Workbench, or the 'unsetup' API call"
+      end
+    end
+  end
+
   def set_initial_username(requested: false)
     if !requested.is_a?(String) || requested.empty?
       email_parts = email.partition("@")
@@ -252,64 +397,90 @@ class User < ArvadosModel
     end
   end
 
-  def update_uuid(new_uuid:)
-    if !current_user.andand.is_admin
-      raise PermissionDeniedError
-    end
-    if uuid == system_user_uuid || uuid == anonymous_user_uuid
-      raise "update_uuid cannot update system accounts"
-    end
-    if self.class != self.class.resource_class_for_uuid(new_uuid)
-      raise "invalid new_uuid #{new_uuid.inspect}"
-    end
-    transaction(requires_new: true) do
-      reload
-      old_uuid = self.uuid
-      self.uuid = new_uuid
-      save!(validate: false)
-      change_all_uuid_refs(old_uuid: old_uuid, new_uuid: new_uuid)
-    end
-  end
-
-  # Move this user's (i.e., self's) owned items into new_owner_uuid.
-  # Also redirect future uses of this account to
-  # redirect_to_user_uuid, i.e., when a caller authenticates to this
-  # account in the future, the account redirect_to_user_uuid account
-  # will be used instead.
+  # Move this user's (i.e., self's) owned items to new_owner_uuid and
+  # new_user_uuid (for things normally owned directly by the user).
+  #
+  # If redirect_auth is true, also reassign auth tokens and ssh keys,
+  # and redirect this account to redirect_to_user_uuid, i.e., when a
+  # caller authenticates to this account in the future, the account
+  # redirect_to_user_uuid account will be used instead.
   #
   # current_user must have admin privileges, i.e., the caller is
   # responsible for checking permission to do this.
-  def merge(new_owner_uuid:, redirect_to_user_uuid:)
+  def merge(new_owner_uuid:, new_user_uuid:, redirect_to_new_user:)
     raise PermissionDeniedError if !current_user.andand.is_admin
-    raise "not implemented" if !redirect_to_user_uuid
+    raise "Missing new_owner_uuid" if !new_owner_uuid
+    raise "Missing new_user_uuid" if !new_user_uuid
     transaction(requires_new: true) do
       reload
       raise "cannot merge an already merged user" if self.redirect_to_user_uuid
 
-      new_user = User.where(uuid: redirect_to_user_uuid).first
+      new_user = User.where(uuid: new_user_uuid).first
       raise "user does not exist" if !new_user
       raise "cannot merge to an already merged user" if new_user.redirect_to_user_uuid
 
-      # Existing API tokens are updated to authenticate to the new
-      # user.
-      ApiClientAuthorization.
-        where(user_id: id).
-        update_all(user_id: new_user.id)
+      self.clear_permissions
+      new_user.clear_permissions
+
+      # If 'self' is a remote user, don't transfer authorizations
+      # (i.e. ability to access the account) to the new user, because
+      # that gives the remote site the ability to access the 'new'
+      # user account that takes over the 'self' account.
+      #
+      # If 'self' is a local user, it is okay to transfer
+      # authorizations, even if the 'new' user is a remote account,
+      # because the remote site does not gain the ability to access an
+      # account it could not before.
+
+      if redirect_to_new_user and self.uuid[0..4] == Rails.configuration.ClusterID
+        # Existing API tokens and ssh keys are updated to authenticate
+        # to the new user.
+        ApiClientAuthorization.
+          where(user_id: id).
+          update_all(user_id: new_user.id)
+
+        user_updates = [
+          [AuthorizedKey, :owner_uuid],
+          [AuthorizedKey, :authorized_user_uuid],
+          [Link, :owner_uuid],
+          [Link, :tail_uuid],
+          [Link, :head_uuid],
+        ]
+      else
+        # Destroy API tokens and ssh keys associated with the old
+        # user.
+        ApiClientAuthorization.where(user_id: id).destroy_all
+        AuthorizedKey.where(owner_uuid: uuid).destroy_all
+        AuthorizedKey.where(authorized_user_uuid: uuid).destroy_all
+        user_updates = [
+          [Link, :owner_uuid],
+          [Link, :tail_uuid]
+        ]
+      end
 
       # References to the old user UUID in the context of a user ID
       # (rather than a "home project" in the project hierarchy) are
       # updated to point to the new user.
-      [
-        [AuthorizedKey, :owner_uuid],
-        [AuthorizedKey, :authorized_user_uuid],
-        [Repository, :owner_uuid],
-        [Link, :owner_uuid],
-        [Link, :tail_uuid],
-        [Link, :head_uuid],
-      ].each do |klass, column|
+      user_updates.each do |klass, column|
         klass.where(column => uuid).update_all(column => new_user.uuid)
       end
 
+      # Need to update repository names to new username
+      if username
+        old_repo_name_re = /^#{Regexp.escape(username)}\//
+        Repository.where(:owner_uuid => uuid).each do |repo|
+          repo.owner_uuid = new_user.uuid
+          repo_name_sub = "#{new_user.username}/"
+          name = repo.name.sub(old_repo_name_re, repo_name_sub)
+          while (conflict = Repository.where(:name => name).first) != nil
+            repo_name_sub += "migrated"
+            name = repo.name.sub(old_repo_name_re, repo_name_sub)
+          end
+          repo.name = name
+          repo.save!
+        end
+      end
+
       # References to the merged user's "home project" are updated to
       # point to new_owner_uuid.
       ActiveRecord::Base.descendants.reject(&:abstract_class?).each do |klass|
@@ -322,13 +493,40 @@ class User < ArvadosModel
         klass.where(owner_uuid: uuid).update_all(owner_uuid: new_owner_uuid)
       end
 
-      update_attributes!(redirect_to_user_uuid: new_user.uuid)
-      invalidate_permissions_cache
+      if redirect_to_new_user
+        update_attributes!(redirect_to_user_uuid: new_user.uuid, username: nil)
+      end
+      skip_check_permissions_against_full_refresh do
+        update_permissions self.uuid, self.uuid, CAN_MANAGE_PERM
+        update_permissions new_user.uuid, new_user.uuid, CAN_MANAGE_PERM
+        update_permissions new_user.owner_uuid, new_user.uuid, CAN_MANAGE_PERM
+      end
+      update_permissions self.owner_uuid, self.uuid, CAN_MANAGE_PERM
     end
   end
 
+  def redirects_to
+    user = self
+    redirects = 0
+    while (uuid = user.redirect_to_user_uuid)
+      break if uuid.empty?
+      nextuser = User.unscoped.find_by_uuid(uuid)
+      if !nextuser
+        raise Exception.new("user uuid #{user.uuid} redirects to nonexistent uuid '#{uuid}'")
+      end
+      user = nextuser
+      redirects += 1
+      if redirects > 15
+        raise "Starting from #{self.uuid} redirect_to_user_uuid exceeded maximum number of redirects"
+      end
+    end
+    user
+  end
+
   def self.register info
-    # login info should have fields:
+    # login info expected fields, all can be optional but at minimum
+    # must supply either 'identity_url' or 'email'
+    #
     #   email
     #   first_name
     #   last_name
@@ -345,61 +543,24 @@ class User < ArvadosModel
       # Only local users can create sessions, hence uuid_like_pattern
       # here.
       user = User.unscoped.where('identity_url = ? and uuid like ?',
-                                 info['identity_url'],
+                                 identity_url,
                                  User.uuid_like_pattern).first
-      if user
-        while (uuid = user.redirect_to_user_uuid)
-          user = User.unscoped.find_by_uuid(uuid)
-          if !user
-            raise Exception.new("user uuid #{user.uuid} redirects to nonexistent uuid #{uuid}")
-          end
-        end
-        primary_user = user
-      end
+      primary_user = user.redirects_to if user
+    end
 
-      # Don't think this is necessary if admin can just create a user
-      # record with the desired email.
-      #
-      # if not user
-      #   # Check for permission to log in to an existing User record with
-      #   # a different identity_url
-      #   Link.where("link_class = ? and name = ? and tail_uuid = ? and head_uuid like ?",
-      #              'permission',
-      #              'can_login',
-      #              info['email'],
-      #              User.uuid_like_pattern).each do |link|
-      #     if prefix = link.properties['identity_url_prefix']
-      #       if prefix == info['identity_url'][0..prefix.size-1]
-      #         user = User.find_by_uuid(link.head_uuid)
-      #         break if user
-      #       end
-      #     end
-      #   end
-      # end
-    end
-
-    if !primary_user and info['email'] and !info['email'].empty?
-      # identity url is unset or didn't find anything.
+    if !primary_user
+      # identity url is unset or didn't find matching record.
       emails = [info['email']] + (info['alternate_emails'] || [])
-      emails.select! {|em| !em.empty?}
-      emails.each do |em|
-        # Go through each email address, try to find a user record
-        # corresponding to one of the addresses supplied.
-
-        user = User.unscoped.where('email = ? and uuid like ?',
-                                   em,
-                                   User.uuid_like_pattern).first
-        next if !user
-
-        while (uuid = user.redirect_to_user_uuid)
-          user = User.unscoped.find_by_uuid(uuid)
-          if !user
-            raise Exception.new("user uuid #{user.uuid} redirects to nonexistent uuid #{uuid}")
-          end
+      emails.select! {|em| !em.nil? && !em.empty?}
+
+      User.unscoped.where('email in (?) and uuid like ?',
+                          emails,
+                          User.uuid_like_pattern).each do |user|
+        if !primary_user
+          primary_user = user.redirects_to
+        elsif primary_user.uuid != user.redirects_to.uuid
+          raise "Ambiguous email address, directs to both #{primary_user.uuid} and #{user.redirects_to.uuid}"
         end
-
-        primary_user = user
-        break
       end
     end
 
@@ -409,24 +570,34 @@ class User < ArvadosModel
                               :is_admin => false,
                               :is_active => Rails.configuration.Users.NewUsersAreActive)
 
-      primary_user.set_initial_username(requested: info['username']) if info['username']
+      primary_user.set_initial_username(requested: info['username']) if info['username'] && !info['username'].blank?
+      primary_user.identity_url = info['identity_url'] if identity_url
     end
 
-    primary_user.email = info['email']
-    primary_user.identity_url = info['identity_url']
-    primary_user.first_name = info['first_name']
-    primary_user.last_name = info['last_name']
+    primary_user.email = info['email'] if info['email']
+    primary_user.first_name = info['first_name'] if info['first_name']
+    primary_user.last_name = info['last_name'] if info['last_name']
+
+    if (!primary_user.email or primary_user.email.empty?) and (!primary_user.identity_url or primary_user.identity_url.empty?)
+      raise "Must have supply at least one of 'email' or 'identity_url' to User.register"
+    end
 
     act_as_system_user do
       primary_user.save!
     end
 
-    return primary_user
-
+    primary_user
   end
 
   protected
 
+  def self.attributes_required_columns
+    super.merge(
+                'can_write' => ['owner_uuid', 'uuid'],
+                'can_manage' => ['owner_uuid', 'uuid'],
+                )
+  end
+
   def change_all_uuid_refs(old_uuid:, new_uuid:)
     ActiveRecord::Base.descendants.reject(&:abstract_class?).each do |klass|
       klass.columns.each do |col|
@@ -443,7 +614,7 @@ class User < ArvadosModel
   end
 
   def permission_to_update
-    if username_changed? || redirect_to_user_uuid_changed?
+    if username_changed? || redirect_to_user_uuid_changed? || email_changed?
       current_user.andand.is_admin
     else
       # users must be able to update themselves (even if they are
@@ -548,30 +719,6 @@ class User < ArvadosModel
     merged
   end
 
-  def create_oid_login_perm(openid_prefix)
-    # Check oid_login_perm
-    oid_login_perms = Link.where(tail_uuid: self.email,
-                                 head_uuid: self.uuid,
-                                 link_class: 'permission',
-                                 name: 'can_login')
-
-    if !oid_login_perms.any?
-      # create openid login permission
-      oid_login_perm = Link.create!(link_class: 'permission',
-                                   name: 'can_login',
-                                   tail_uuid: self.email,
-                                   head_uuid: self.uuid,
-                                   properties: {
-                                     "identity_url_prefix" => openid_prefix,
-                                   })
-      logger.info { "openid login permission: " + oid_login_perm[:uuid] }
-    else
-      oid_login_perm = oid_login_perms.first
-    end
-
-    return oid_login_perm
-  end
-
   def create_user_repo_link(repo_name)
     # repo_name is optional
     if not repo_name
@@ -617,16 +764,26 @@ class User < ArvadosModel
     login_perm
   end
 
-  # add the user to the 'All users' group
-  def create_user_group_link
-    return (Link.where(tail_uuid: self.uuid,
-                       head_uuid: all_users_group[:uuid],
+  def add_to_all_users_group
+    resp = [Link.where(tail_uuid: self.uuid,
+                       head_uuid: all_users_group_uuid,
                        link_class: 'permission',
-                       name: 'can_read').first or
+                       name: 'can_read').first ||
             Link.create(tail_uuid: self.uuid,
-                        head_uuid: all_users_group[:uuid],
+                        head_uuid: all_users_group_uuid,
                         link_class: 'permission',
-                        name: 'can_read'))
+                        name: 'can_read')]
+    if Rails.configuration.Users.ActivatedUsersAreVisibleToOthers
+      resp += [Link.where(tail_uuid: all_users_group_uuid,
+                          head_uuid: self.uuid,
+                          link_class: 'permission',
+                          name: 'can_read').first ||
+               Link.create(tail_uuid: all_users_group_uuid,
+                           head_uuid: self.uuid,
+                           link_class: 'permission',
+                           name: 'can_read')]
+    end
+    return resp
   end
 
   # Give the special "System group" permission to manage this user and
@@ -652,31 +809,21 @@ class User < ArvadosModel
   # Automatically setup if is_active flag turns on
   def setup_on_activate
     return if [system_user_uuid, anonymous_user_uuid].include?(self.uuid)
-    if is_active && (new_record? || is_active_changed?)
-      setup(openid_prefix: Rails.configuration.default_openid_prefix)
+    if is_active &&
+      (new_record? || saved_change_to_is_active? || will_save_change_to_is_active?)
+      setup
     end
   end
 
   # Automatically setup new user during creation
   def auto_setup_new_user
-    setup(openid_prefix: Rails.configuration.default_openid_prefix)
-    if username
-      create_vm_login_permission_link(Rails.configuration.Users.AutoSetupNewUsersWithVmUUID,
-                                      username)
-      repo_name = "#{username}/#{username}"
-      if Rails.configuration.Users.AutoSetupNewUsersWithRepository and
-          Repository.where(name: repo_name).first.nil?
-        repo = Repository.create!(name: repo_name, owner_uuid: uuid)
-        Link.create!(tail_uuid: uuid, head_uuid: repo.uuid,
-                     link_class: "permission", name: "can_manage")
-      end
-    end
+    setup
   end
 
   # Send notification if the user saved profile for the first time
   def send_profile_created_notification
-    if self.prefs_changed?
-      if self.prefs_was.andand.empty? || !self.prefs_was.andand['profile']
+    if saved_change_to_prefs?
+      if prefs_before_last_save.andand.empty? || !prefs_before_last_save.andand['profile']
         profile_notification_address = Rails.configuration.Users.UserProfileNotificationAddress
         ProfileNotifier.profile_created(self, profile_notification_address).deliver_now if profile_notification_address and !profile_notification_address.empty?
       end
@@ -691,11 +838,17 @@ class User < ArvadosModel
   end
 
   def sync_repository_names
-    old_name_re = /^#{Regexp.escape(username_was)}\//
+    old_name_re = /^#{Regexp.escape(username_before_last_save)}\//
     name_sub = "#{username}/"
     repositories.find_each do |repo|
       repo.name = repo.name.sub(old_name_re, name_sub)
       repo.save!
     end
   end
+
+  def identity_url_nil_if_empty
+    if identity_url == ""
+      self.identity_url = nil
+    end
+  end
 end