Announcing the Ability to Disable Apple System Integrity Protection on Amazon EC2 Mac Instances
In a significant development for developers using Amazon EC2 Mac instances, there is now the capability to programmatically disable Apple’s System Integrity Protection (SIP). SIP, introduced by Apple in its OS X El Capitan (2015, version 10.11), is a security feature designed to safeguard the system by limiting the root user account’s abilities. It’s worth noting that SIP is activated by default on macOS systems.
Understanding System Integrity Protection (SIP)
SIP is an essential security measure that offers robust protection against malicious software. It achieves this by preventing unauthorized modification of protected files and folders, restricting access to system-owned directories, and blocking unauthorized software from choosing a startup disk. The primary objective of SIP is to mitigate security risks associated with unrestricted root access. Without SIP, malware could potentially take over an entire device using a single password or exploit. By implementing SIP, Apple aims to provide a higher level of security for macOS users, many of whom operate administrative accounts with weak or non-existent passwords.
Why Developers Might Need to Disable SIP
While SIP is a valuable protective measure, there are instances where developers may need to temporarily disable it. This is particularly the case when developing new device drivers or system extensions, where SIP must be disabled to install and test the code. Additionally, SIP might impede access to certain system settings required for specific software to function correctly. Temporarily disabling SIP grants developers the necessary permissions to fine-tune macOS programs, akin to opening a vault door briefly for authorized maintenance.
Traditional Methods of Disabling SIP
Traditionally, disabling SIP on a Mac required physical access to the machine. This involved restarting the machine in recovery mode and using the csrutil command line tool to disable SIP, followed by another restart. Until recently, users of EC2 Mac instances had to operate under standard SIP settings, as the requirement for physical access and recovery mode booting made integration with the Amazon EC2 control plane and EC2 API challenging.
New Capability on Amazon EC2 Mac Instances
The landscape has changed. Developers can now disable and re-enable SIP on Amazon EC2 Mac instances at will. This flexibility is made possible by a new EC2 API: CreateMacSystemIntegrityProtectionModificationTask. This asynchronous API initiates the process of changing the SIP status on the instance, with progress monitored through another new EC2 API: DescribeMacModificationTasks. All developers need is the instance ID of the machine they intend to work with.
Prerequisites for Disabling SIP
Before utilizing the new EC2 API on Apple silicon-based EC2 Mac instances or newer machines, developers must set the ec2-user user password and enable a secure token for that user on macOS. This involves connecting to the machine and entering two commands in the terminal:
- Setting a password for the
ec2-useruser. - Enabling a secure token for the
ec2-user.It’s normal to encounter a KeyChain error during this process, which can be ignored.
Executing the SIP Status Change
Once the prerequisites are met, developers do not need to connect to the machine to toggle the SIP status. Using the AWS Command Line Interface (AWS CLI), developers can retrieve the Amazon EC2 Mac instance ID and disable SIP with the
create-mac-system-integrity-protection-modification-taskcommand. The task’s status can be checked using theaws ec2 describe-mac-modification-taskscommand. The instance will undergo a series of reboots during this process, rendering it temporarily unreachable. This operation typically takes 60–90 minutes to complete, after which the instance becomes accessible again.When to Disable SIP
Disabling SIP should be approached with caution due to the security risks it introduces. However, it may be necessary when developing device drivers or kernel extensions for macOS, or when older applications that require SIP to be disabled to function correctly are used. Disabling SIP is also required to deactivate Spotlight indexing on servers, freeing up CPU cycles and disk I/O.
Additional Considerations
There are several important considerations to keep in mind regarding disabling SIP on Amazon EC2 Mac:
- Disabling SIP is available through the API, AWS SDKs, AWS CLI, and the AWS Management Console.
- On Apple silicon, the setting is volume-based, meaning SIP must be disabled again if the root volume is replaced. On Intel, the setting is Mac host-based, so SIP remains disabled if the root volume is replaced.
- Stopping and starting an instance re-enables SIP, while rebooting does not change its status.
- SIP status is not transferable between EBS volumes. Therefore, SIP will need to be disabled again after restoring an instance from an EBS snapshot or creating an AMI from an instance with SIP enabled.
This new functionality is available in all regions where Amazon EC2 Mac is offered, at no additional cost. Developers are encouraged to try it out and experience the flexibility it offers for macOS development on Amazon EC2 Mac instances.
For more information, please visit the official announcement on the AWS website.
For more Information, Refer to this article.
