What’s New in XCreds 3.1

Active Directory Login

New username and password window allows logging in with local user or Active Directory (if ADDomain key is defined).

New Username and Password Window

We no longer use the macOS login window and use the new XCreds username/password window. This allows for faster switching and Active Directory login.

Switch to Login Window at Screen Saver

When the “shouldSwitchToLoginWindowWhenLocked” key is set and XCreds is running in the user session and the screen is locked, the lock screen will fast user switch to the log

When set to true and the user locks the current session, XCreds will tell the system to switch to Login Window. The current session will stay active but the user will login with the XCreds Login Window to resume the session.

Admin Group

If group membership is returned in the “groups” claim and matches the group defined in the “CreateAdminIfGroupMember” preference, the user will be created as admin.

kerberos ticket

When app is first launched and their is a keychain item with a AD account and local password, a kerberos ticket will be attempted.

Override Preference Script

Most preferences can now be overwritten by specifying a script at the path defined by “settingsOverrideScriptPath”. This script, if it exists, owned by _securityagent, and has permissions 700 (writable only by securityagent, readable and executable by securityagent) must return a valid plist that defines the key/value pairs to override in preferences. This allows for basing preferences based on the local state of the machine. It is important for the “localAdminUserName” and “localAdminPassword” keys. See Reset Keychain for more information on this. The override script can also be used for querying the local state and setting preferences. For example, to randomly set the background image, a sample script “settingsOverrideScriptPath” defines a script:

#!/bin/sh
dir="/System/Library/Desktop Pictures"
desktoppicture=`/bin/ls -1 "$dir"/*.heic | sort --random-sort | head -1`

cat /usr/local/xcreds/override.plist|sed "s|DESKTOPPICTUREPATH|${desktoppicture}|g"

The plist would defined as:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>loginWindowBackgroundImageURL</key>
    <string>file://DESKTOPPICTUREPATH</string>
</dict>
</plist>

Reset Keychain

In prior versions of XCreds, the ability to reset the keychain if the user forgets their local password would fail due to the lack of an admin user with a secure token. This would cause the “PasswordOverwriteSilent” to fail.

The “settingsOverrideScriptPath” (see above) can return the admin username and password of an admin account that has a secure token. This admin user is then used to reset the user’s keychain if they forgot their local password. This can either be done with user prompting or silently.

The script can find those keys via curl, in system keychain, or in a LAPS file and return the values inside the plist that is returned. This gives flexablity in determining the security required for the local admin username and password.

Note that XCreds assumes an admin user with a secure token already exists on the machine and XCreds does not create or manage this user. If you manage local admin via a LAPS system, you can return the password from the local password file.

An example of an override script to return username and password are as follows:

Override Script:

#!/bin/sh
dir="/System/Library/Desktop Pictures"
desktoppicture=/bin/ls -1 "$dir"/*.heic | sort --random-sort | head -1

#this is provided as an example. DO NOT KEEP ADMIN CREDENTIALS ON DISK! Use curl or other method for getting them temporarily.
admin_username="tcadmin"
admin_password="twocanoes"

cat /usr/local/xcreds/override.plist | sed "s|LOCALADMINUSERNAME|${admin_username}|g" | sed "s|LOCALADMINPASSWORD|${admin_password}|g"

plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>localAdminUserName</key>
<string>LOCALADMINUSERNAME</string>
<key>localAdminPassword</key>
<string>LOCALADMINPASSWORD</string>
</dict>
</plist>

Others

• added shake to password field

New Keys

ADDomain

The desired AD domain

CreateAdminIfGroupMember

List of groups that should have its members created as local administrators. Set as an Array of Strings of the group name.

shouldSwitchToLoginWindowWhenLocked

When set to true and the user locks the current session, XCreds will tell the system to switch to Login Window. The current session will stay active but the user will login with the XCreds Login Window to resume the session.

settingsOverrideScriptPath

Script to override defaults. Must return valid property list with specified defaults. Script must exist at path, be owned by root and only writable by root.

localAdminUserName

Username of local admin user. DO NOT SET THIS IN PREFERENCES. It is recommended to set this with the settingsOverrideScriptPath script. This user is used to reset the keychain if the user forgets their local password and to setup a secure token for newly created users.

localAdminPassword

Password of local admin user. DO NOT SET THIS IN PREFERENCES. It is recommended to set this with the settingsOverrideScriptPath script. This user is used to reset the keychain if the user forgets their local password and to setup a secure token for newly created users.

shouldFindPasswordElement

Selects the password element field in the web page by finding a form element that has bullets (input is password)

shouldShowCloudLoginByDefault

Determine if the Mac Login Window or the Cloud Login Window is shown by default

shouldShowMacLoginButton

Show the Mac Login Window button in XCreds Login