Updated MigrateADMobileAccounttoLocalAccount script now available to fix migration bug

A couple of years back, I wrote a script to assist with migrating AD mobile users to local users. In my testing in 2016, everything seemed to work right and I didn’t see any problems with it on OS X El Capitan.

Fast forward a couple of years and a colleague of mine, Per Oloffson, began running into a weird problem with upgrading Macs from Sierra to High Sierra. When he upgraded Macs from macOS Sierra to macOS High Sierra, he was finding that Macs that had been migrated from AD mobile accounts to local accounts were having those same accounts break.

https://twitter.com/MagerValp/status/1007664677386637312

After a considerable amount of troubleshooting, he was able to narrow it down to the macOS High Sierra installer changing the password hash on those accounts. But why was it changing them?

https://twitter.com/MagerValp/status/1007664753362243585

In short, it was changing them because of a bug in my original MigrateADMobileAccounttoLocalAccount.command interactive migration script. Sorry, Per. For more details, please see below the jump.

The problematic sections are highlighted below. When the script backed up the AD mobile account’s password and then restored it, it was adding single quotes to the beginning and end of the password hash string.

The password hash string should have looked like this:

Instead, it looked like this:

The odd part of the situation is that macOS Sierra was seemingly OK with the extra characters in the password string. It wasn’t until the macOS High Sierra installer re-checked and altered the account plist that the problem occurred.

To fix the migration process, I’ve updated the script to better handle the account password backup and restoration process. The backup process is now querying dscl for the correct XML output and restoring it, which should address the problem with the script.

In my testing, the password hash is now appearing correctly in the account’s plist file.

Testing

This script has been tested and verified to migrate AD mobile accounts to local accounts on the following versions of macOS:

• macOS 10.13.5

In that testing, I did the following:

Testing on logged-in AD mobile user account:

1. I set up an AD-bound VM and created an AD mobile account with admin privileges.
2. I logged into the AD mobile account and ran the script while logged in as that account.
3. Once the account had been migrated, I rebooted and verified that I could log in at the OS login window.
4. I changed the password for the local account to a new one and rebooted.
5. I verified that I could log in at the OS login window with the new password.

Testing on logged-out AD mobile user account:

1. I set up an AD-bound VM and created an AD mobile account with admin privileges.
2. I logged into the VM using a local account which was not the AD mobile account and ran the script while logged in as that account.
3. Once the account had been migrated, I logged out and verified that I could log in at the OS login window with the just-migrated account.
4. I changed the password for the newly-migrated local account to a new one and rebooted.
5. I verified that I could log in at the OS login window with the new password.

Note: I did not test with FileVault-enabled accounts.

Advisory: Older versions of OS X and macOS were not tested and I have no idea if the script will work on those older OS versions.

Warning: I was able to test in my shop’s AD environment and verified that everything worked. That does not guarantee it will work in your environment. Test thoroughly before deploying in your own AD environment.

The updated script is available below, and also available on GitHub at the following address:

https://github.com/rtrouton/rtrouton_scripts/tree/master/rtrouton_scripts/migrate_ad_mobile_account_to_local_account

	#!/bin/bash
	# Modified 4/5/2019
	Version=1.4
	# Original source is from MigrateUserHomeToDomainAcct.sh
	# Written by Patrick Gallagher – https://twitter.com/patgmac
	#
	# Guidance and inspiration from Lisa Davies:
	# http://lisacherie.com/?p=239
	#
	# Modified by Rich Trouton
	#
	# Version 1.0 – Migrates an Active Directory mobile account to a local account by the following process:
	# 1. Detect if the Mac is bound to AD and offer to unbind the Mac from AD if desired
	# 2. Display a list of the accounts with a UID greater than 1000
	# 3. Remove the following attributes from the specified account:
	#
	# cached_groups
	# cached_auth_policy
	# CopyTimestamp – This attribute is used by the OS to determine if the account is a mobile account
	# SMBPrimaryGroupSID
	# OriginalAuthenticationAuthority
	# OriginalNodeName
	# SMBSID
	# SMBScriptPath
	# SMBPasswordLastSet
	# SMBGroupRID
	# PrimaryNTDomain
	# AppleMetaRecordName
	# MCXSettings
	# MCXFlags
	#
	# 4. Selectively modify the account's AuthenticationAuthority attribute to remove AD-specific attributes.
	# 5. Restart the directory services process
	# 6. Check to see if the conversion process succeeded by checking the OriginalNodeName attribute for the value "Active Directory"
	# 7. If the conversion process succeeded, update the permissions on the account's home folder.
	# 8. Prompt if admin rights should be granted for the specified account
	#
	# Version 1.1
	#
	# Changes:
	#
	# 1. After conversion, the specified account is added to the staff group. All local accounts on this Mac are members of the staff group,
	# but AD mobile accounts are not members of the staff group.
	# 2. The "accounttype" variable is now checking the AuthenticationAuthority attribute instead of the OriginalNodeName attribute.
	# The reason for Change 2's attributes change is that the AuthenticationAuthority attribute will exist following the conversion
	# process while the OriginalNodeName attribute may not.
	#
	#
	# Version 1.2
	#
	# Changes:
	#
	# Add RemoveAD function to handle the following tasks:
	#
	# 1. Force unbind the Mac from Active Directory
	# 2. Deletes the Active Directory domain from the custom /Search and /Search/Contacts paths
	# 3. Changes the /Search and /Search/Contacts path type from Custom to Automatic
	#
	# Thanks to Rick Lemmon for the suggested changes to the AD unbind process.
	#
	# Version 1.3
	#
	# Changes:
	#
	# Fix to account password backup and restore process. Previous versions
	# of the script were adding extra quote marks to the account's plist
	# file located in /var/db/dslocal/nodes/Default/users/.
	#
	# Version 1.4
	#
	# Changes:
	#
	# macOS 10.14.4 will remove the the actual ShadowHashData key immediately
	# if the AuthenticationAuthority array value which references the ShadowHash
	# is removed from the AuthenticationAuthority array. To address this, the
	# existing AuthenticationAuthority array will be modified to remove the Kerberos
	# and LocalCachedUser user values.
	#
	# Thanks to the anonymous reporter who provided the bug report and fix.
	clear
	listUsers="$(/usr/bin/dscl . list /Users UniqueID | awk '$2 > 1000 {print $1}') FINISHED"
	FullScriptName=`basename "$0"`
	ShowVersion="$FullScriptName $Version"
	check4AD=`/usr/bin/dscl localhost -list . | grep "Active Directory"`
	osvers=$(sw_vers -productVersion | awk -F. '{print $2}')
	/bin/echo "********* Running $FullScriptName Version $Version *********"
	RunAsRoot()
	{
	## Pass in the full path to the executable as $1
	if [[ "${USER}" != "root" ]] ; then
	/bin/echo
	/bin/echo "*** This application must be run as root. Please authenticate below. ***"
	/bin/echo
	sudo "${1}" && exit 0
	fi
	}
	RemoveAD(){
	# This function force-unbinds the Mac from the existing Active Directory domain
	# and updates the search path settings to remove references to Active Directory
	searchPath=`/usr/bin/dscl /Search -read . CSPSearchPath | grep Active\ Directory | sed 's/^ //'`
	# Force unbind from Active Directory
	/usr/sbin/dsconfigad -remove -force -u none -p none
	# Deletes the Active Directory domain from the custom /Search
	# and /Search/Contacts paths
	/usr/bin/dscl /Search/Contacts -delete . CSPSearchPath "$searchPath"
	/usr/bin/dscl /Search -delete . CSPSearchPath "$searchPath"
	# Changes the /Search and /Search/Contacts path type from Custom to Automatic
	/usr/bin/dscl /Search -change . SearchPolicy dsAttrTypeStandard:CSPSearchPath dsAttrTypeStandard:NSPSearchPath
	/usr/bin/dscl /Search/Contacts -change . SearchPolicy dsAttrTypeStandard:CSPSearchPath dsAttrTypeStandard:NSPSearchPath
	}
	PasswordMigration(){
	# macOS 10.14.4 will remove the the actual ShadowHashData key immediately
	# if the AuthenticationAuthority array value which references the ShadowHash
	# is removed from the AuthenticationAuthority array. To address this, the
	# existing AuthenticationAuthority array will be modified to remove the Kerberos
	# and LocalCachedUser user values.
	AuthenticationAuthority=$(/usr/bin/dscl -plist . -read /Users/$netname AuthenticationAuthority)
	Kerberosv5=$(echo "${AuthenticationAuthority}" | xmllint –xpath 'string(//string[contains(text(),"Kerberosv5")])' –)
	LocalCachedUser=$(echo "${AuthenticationAuthority}" | xmllint –xpath 'string(//string[contains(text(),"LocalCachedUser")])' –)
	# Remove Kerberosv5 and LocalCachedUser
	if [[ ! -z "${Kerberosv5}" ]]; then
	/usr/bin/dscl -plist . -delete /Users/$netname AuthenticationAuthority "${Kerberosv5}"
	fi
	if [[ ! -z "${LocalCachedUser}" ]]; then
	/usr/bin/dscl -plist . -delete /Users/$netname AuthenticationAuthority "${LocalCachedUser}"
	fi
	}
	RunAsRoot "${0}"
	# Check for AD binding and offer to unbind if found.
	if [[ "${check4AD}" = "Active Directory" ]]; then
	/usr/bin/printf "This machine is bound to Active Directory.\nDo you want to unbind this Mac from AD?\n"
	select yn in "Yes" "No"; do
	case $yn in
	Yes) RemoveAD; /bin/echo "AD binding has been removed."; break;;
	No) /bin/echo "Active Directory binding is still active."; break;;
	esac
	done
	fi
	until [ "$user" == "FINISHED" ]; do
	/usr/bin/printf "%b" "\a\n\nSelect a user to convert or select FINISHED:\n" >&2
	select netname in $listUsers; do
	if [ "$netname" = "FINISHED" ]; then
	/bin/echo "Finished converting users to local accounts"
	exit 0
	fi
	accounttype=`/usr/bin/dscl . -read /Users/"$netname" AuthenticationAuthority | head -2 | awk -F'/' '{print $2}' | tr -d '\n'`
	if [[ "$accounttype" = "Active Directory" ]]; then
	mobileusercheck=`/usr/bin/dscl . -read /Users/"$netname" AuthenticationAuthority | head -2 | awk -F'/' '{print $1}' | tr -d '\n' | sed 's/^[^:]*: //' | sed s/\;/""/g`
	if [[ "$mobileusercheck" = "LocalCachedUser" ]]; then
	/usr/bin/printf "$netname has an AD mobile account.\nConverting to a local account with the same username and UID.\n"
	else
	/usr/bin/printf "The $netname account is not a AD mobile account\n"
	break
	fi
	else
	/usr/bin/printf "The $netname account is not a AD mobile account\n"
	break
	fi
	# Remove the account attributes that identify it as an Active Directory mobile account
	/usr/bin/dscl . -delete /users/$netname cached_groups
	/usr/bin/dscl . -delete /users/$netname cached_auth_policy
	/usr/bin/dscl . -delete /users/$netname CopyTimestamp
	/usr/bin/dscl . -delete /users/$netname AltSecurityIdentities
	/usr/bin/dscl . -delete /users/$netname SMBPrimaryGroupSID
	/usr/bin/dscl . -delete /users/$netname OriginalAuthenticationAuthority
	/usr/bin/dscl . -delete /users/$netname OriginalNodeName
	/usr/bin/dscl . -delete /users/$netname SMBSID
	/usr/bin/dscl . -delete /users/$netname SMBScriptPath
	/usr/bin/dscl . -delete /users/$netname SMBPasswordLastSet
	/usr/bin/dscl . -delete /users/$netname SMBGroupRID
	/usr/bin/dscl . -delete /users/$netname PrimaryNTDomain
	/usr/bin/dscl . -delete /users/$netname AppleMetaRecordName
	/usr/bin/dscl . -delete /users/$netname PrimaryNTDomain
	/usr/bin/dscl . -delete /users/$netname MCXSettings
	/usr/bin/dscl . -delete /users/$netname MCXFlags
	# Migrate password and remove AD-related attributes
	PasswordMigration
	# Refresh Directory Services
	if [[ ${osvers} -ge 7 ]]; then
	/usr/bin/killall opendirectoryd
	else
	/usr/bin/killall DirectoryService
	fi
	sleep 20
	accounttype=`/usr/bin/dscl . -read /Users/"$netname" AuthenticationAuthority | head -2 | awk -F'/' '{print $2}' | tr -d '\n'`
	if [[ "$accounttype" = "Active Directory" ]]; then
	/usr/bin/printf "Something went wrong with the conversion process.\nThe $netname account is still an AD mobile account.\n"
	exit 1
	else
	/usr/bin/printf "Conversion process was successful.\nThe $netname account is now a local account.\n"
	fi
	homedir=`/usr/bin/dscl . -read /Users/"$netname" NFSHomeDirectory | awk '{print $2}'`
	if [[ "$homedir" != "" ]]; then
	/bin/echo "Home directory location: $homedir"
	/bin/echo "Updating home folder permissions for the $netname account"
	/usr/sbin/chown -R "$netname" "$homedir"
	fi
	# Add user to the staff group on the Mac
	/bin/echo "Adding $netname to the staff group on this Mac."
	/usr/sbin/dseditgroup -o edit -a "$netname" -t user staff
	/bin/echo "Displaying user and group information for the $netname account"
	/usr/bin/id $netname
	# Prompt to see if the local account should be give admin rights.
	/bin/echo "Do you want to give the $netname account admin rights?"
	select yn in "Yes" "No"; do
	case $yn in
	Yes) /usr/sbin/dseditgroup -o edit -a "$netname" -t user admin; /bin/echo "Admin rights given to this account"; break;;
	No ) /bin/echo "No admin rights given"; break;;
	esac
	done
	break
	done
	done

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