mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-11-09 16:00:22 +00:00
64c5be5242
This commit updates the key rotation docs with the following changes: - Do not call LuksVerify - Mention specifics of RWX volumes - Rename the file to represent RBD backed volumes Signed-off-by: black-dragon74 <niryadav@redhat.com>
72 lines
2.4 KiB
Markdown
72 lines
2.4 KiB
Markdown
# Encryption Key Rotation
|
|
|
|
## Proposal
|
|
|
|
Subject of this proposal is to add support for rotation of
|
|
encryption keys (KEKs) for encrypted volumes in Ceph-CSI.
|
|
|
|
Support for rotating keys on RWX/ROX volumes and filesystem encryption
|
|
with `fscrypt` is out of scope for now and shall be added later.
|
|
|
|
## Document Terminology
|
|
|
|
- Encryption Key: The passphrase that is used to encrypt and open the device.
|
|
- LUKS: The specification used by dm-crypt to process encrypted volumes on linux.
|
|
|
|
## Proposed Solution
|
|
|
|
The proposed solution in this document, is to address the rotation
|
|
of encryption keys for encrypted volumes.
|
|
|
|
This document outlines the rotation steps for PVCs backed by RBD.
|
|
|
|
### Implementation Summary
|
|
|
|
This feature builds upon the foundation laid by encrypted pvcs.
|
|
|
|
The following new methods are added to `cryptsetup.go` for
|
|
handling the key rotation.
|
|
|
|
- `LuksAddKey`: Adds a new key to specified LUKS slot
|
|
- `LuksRemoveKey`: Removes the specified key from its slot using `luksKillSlot`
|
|
- `LuksVerifyKey`: Verifies that the given key exists
|
|
in the given slot using `luksChangeKey`.
|
|
|
|
### Implementation Details
|
|
|
|
The encryption key rotation request will contain with it
|
|
the volume ID and secrets.
|
|
|
|
The secrets are used to generate the credentials for authenticating
|
|
against a ceph cluster.
|
|
|
|
These values are then used to call `GenVolFromVolID` to get the
|
|
rbdVolume structure.
|
|
|
|
The `VolumeEncryption` struct is modified to make
|
|
`generateNewEncryptionPassphrase` a public member function.
|
|
|
|
The `EncryptionKeyRotation` service is registered and implemented
|
|
on the node-plugin.
|
|
|
|
The following steps are followed to process the device for key rotation:
|
|
|
|
- Create a `rbdvolume` object using volume ID,
|
|
this is done by `GenVolFromVolID`.
|
|
- Fetch the current key from the KMS, it is needed for
|
|
subsequent LUKS operations.
|
|
- Get the device path for the volume by calling `waitForPath` as all LUKS
|
|
operations require the device path.
|
|
- Add the fetched key to LUKS slot 1, this will serve as a backup of the key.
|
|
- Generate a new key and store it locally. It will be updated
|
|
in the KMS at later steps.
|
|
- Remove the existing key from slot 0 upon verifying that the
|
|
key in KMS == the key in slot 0.
|
|
- Add new key to slot 0.
|
|
- Update the new key in the KMS.
|
|
- Fetch the key again and verify that the
|
|
key in KMS == the new key we generated.
|
|
- We can now remove the backup key from slot 1.
|
|
|
|
Note that the key in the KMS can always be used to unlock the volume.
|