Auto LUKS Unlock With FIPS Enabled

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Introduction

In this article, we will explore the process of auto-unlocking LUKS-encrypted disks with FIPS (Federal Information Processing Standard) mode enabled. We will delve into the challenges of binding the key in FIPS mode and provide a step-by-step guide on how to achieve auto-unlock with FIPS enabled.

Understanding LUKS and FIPS

LUKS (Linux Unified Key Setup) is a disk encryption standard for Linux operating systems. It provides a secure way to encrypt disks and offers features like password-based authentication and key management. FIPS, on the other hand, is a set of standards for cryptographic modules that ensures the security and integrity of cryptographic operations.

The Challenge of Auto-LUKS Unlock with FIPS

When FIPS mode is enabled, the system's cryptographic operations are restricted to FIPS-compliant algorithms. However, this restriction can cause issues with binding the key in LUKS, which is required for auto-unlock. In this scenario, the system is unable to bind the key, and auto-unlock stops working.

Pre-requisites

Before we dive into the solution, ensure that you have the following:

  • Ubuntu 22.04 installed
  • Two disks encrypted with LUKS
  • TPM (Trusted Platform Module) enabled
  • FIPS mode enabled

Step 1: Disable FIPS Mode and Bind the Key

To bind the key, you need to disable FIPS mode. This will allow you to bind the key, but it will also disable FIPS mode. Once the key is bound, you can re-enable FIPS mode.

sudo sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT=".*"/GRUB_CMDLINE_LINUX_DEFAULT="noprompt"/' /etc/default/grub
sudo update-grub

Step 2: Bind the Key

Bind the key using the following command:

sudo cryptsetup -v --key-slot 0 --key-file /path/to/key.bin luksBind /dev/sdX

Replace /path/to/key.bin with the actual path to your key file and /dev/sdX with the actual device name of your LUKS-encrypted disk.

Step 3: Re-enable FIPS Mode

Re-enable FIPS mode by adding the following line to the /etc/default/grub file:

GRUB_CMDLINE_LINUX_DEFAULT="fips=1"

Update the GRUB configuration:

sudo update-grub

Step 4: Configure Auto-LUKS Unlock

To configure auto-LUKS unlock, you need to create a luks-tpm2 configuration file. Create a new file /etc/luks-tpm2.conf with the following content:

[global]
key-slot=0
key-file=/path/to/key.bin

Replace /path/to/key.bin with the actual path to your key file.

Step 5: Configure TPM2

Configure TPM2 by creating a new file /etc/tpm2-udev.conf with the following content:

ACTION=="add", RUN+="/usr/bin/tpm-udev --device=/dev/%k --key-slot=0 --key-file=/path/to/key.bin"

Replace /path/to/key.bin with the actual path to your key file.

Conclusion

Auto-unlocking LUKS-encrypted disks with FIPS mode enabled requires careful configuration and key management. By following the steps outlined in this article, you should be able to achieve auto-unlock with FIPS enabled. However, if you encounter any issues, refer to the additional information provided in the askubuntu forum post.

Troubleshooting

If you encounter any issues during the process, refer to the following troubleshooting steps:

  • Check the FIPS mode status using the following command: sudo cat /sys/module/fips/parameters/enabled
  • Verify that the key is bound correctly using the following command: sudo cryptsetup -v --key-slot 0 --key-file /path/to/key.bin luksDump /dev/sdX
  • Check the TPM2 configuration using the following command: sudo cat /etc/tpm2-udev.conf

Additional Resources

For more information on LUKS and FIPS, refer to the following resources:

Q: What is the difference between LUKS and FIPS?

A: LUKS (Linux Unified Key Setup) is a disk encryption standard for Linux operating systems, while FIPS (Federal Information Processing Standard) is a set of standards for cryptographic modules that ensures the security and integrity of cryptographic operations.

Q: Why does FIPS mode cause issues with auto-LUKS unlock?

A: FIPS mode restricts the system's cryptographic operations to FIPS-compliant algorithms, which can cause issues with binding the key in LUKS, required for auto-unlock.

Q: How do I disable FIPS mode and bind the key?

A: To disable FIPS mode and bind the key, you need to add the following line to the /etc/default/grub file:

GRUB_CMDLINE_LINUX_DEFAULT="noprompt"

Update the GRUB configuration:

sudo update-grub

Then, bind the key using the following command:

sudo cryptsetup -v --key-slot 0 --key-file /path/to/key.bin luksBind /dev/sdX

Replace /path/to/key.bin with the actual path to your key file and /dev/sdX with the actual device name of your LUKS-encrypted disk.

Q: How do I re-enable FIPS mode after binding the key?

A: To re-enable FIPS mode, add the following line to the /etc/default/grub file:

GRUB_CMDLINE_LINUX_DEFAULT="fips=1"

Update the GRUB configuration:

sudo update-grub

Q: What is the purpose of the luks-tpm2 configuration file?

A: The luks-tpm2 configuration file is used to configure auto-LUKS unlock. It specifies the key slot and key file to use for auto-unlock.

Q: How do I configure TPM2 for auto-LUKS unlock?

A: To configure TPM2 for auto-LUKS unlock, create a new file /etc/tpm2-udev.conf with the following content:

ACTION=="add", RUN+="/usr/bin/tpm-udev --device=/dev/%k --key-slot=0 --key-file=/path/to/key.bin"

Replace /path/to/key.bin with the actual path to your key file.

Q: What are some common issues that may occur during auto-LUKS unlock with FIPS enabled?

A: Some common issues that may occur during auto-LUKS unlock with FIPS enabled include:

  • FIPS mode not being enabled correctly
  • Key not being bound correctly
  • TPM2 configuration not being set correctly

Q: How do I troubleshoot issues with auto-LUKS unlock with FIPS enabled?

A: To troubleshoot issues with auto-LUKS unlock with FIPS enabled, refer to the following steps:

  • Check the FIPS mode status using the following command: sudo cat /sys/module/fips/parameters/enabled
  • Verify that the key is bound correctly using the following command: sudo cryptsetup -v --key-slot 0 --key-file /path/to/key.bin luksDump /dev/sdX
  • Check the TPM2 configuration using the following command: sudo cat /etc/tpm2-udev.conf

Q: What are some additional resources for learning more about LUKS and FIPS?

A: Some additional resources for learning more about LUKS and FIPS include:

By following the steps outlined in this article and referring to the additional resources, you should be able to achieve auto-unlock with FIPS enabled.