1.9 KiB
Clevis
Clevis is a framework for automated decryption of resources. Clevis allows for secure unattended disk decryption during boot, using decryption policies that must be satisfied for the data to decrypt.
Create a JWE file containing your secret
The first step is to embed your secret in a JWE file. JWE files have to be created through the clevis command line. 3 types of policies are supported:
- TPM policies
Secrets are pinned against the presence of a TPM2 device, for example:
echo -n hi | clevis encrypt tpm2 '{}' > hi.jwe
- Tang policies
Secrets are pinned against the presence of a Tang server, for example:
echo -n hi | clevis encrypt tang '{"url": "http://tang.local"}' > hi.jwe
- Shamir Secret Sharing
Using Shamir's Secret Sharing (sss), secrets are pinned using a combination of the two preceding policies. For example:
echo -n hi | clevis encrypt sss \
'{"t": 2, "pins": {"tpm2": {"pcr_ids": "0"}, "tang": {"url": "http://tang.local"}}}' \
> hi.jwe
For more complete documentation on how to generate a secret with clevis, see the clevis documentation.
Activate unattended decryption of a resource at boot
In order to activate unattended decryption of a resource at boot, enable the clevis
module:
{
boot.initrd.clevis.enable = true;
}
Then, specify the device you want to decrypt using a given clevis secret. Clevis will automatically try to decrypt the device at boot and will fallback to interactive unlocking if the decryption policy is not fulfilled.
{
boot.initrd.clevis.devices."/dev/nvme0n1p1".secretFile = ./nvme0n1p1.jwe;
}
Only bcachefs
, zfs
and luks
encrypted devices are supported at this time.