Red Hat Summit19.3. Tang server encryption key management
The cryptographic mechanism to recreate the encryption key is based on the blinded key stored on the node and the private key of the involved Tang servers.
To protect against the possibility of an attacker who has obtained both the Tang server private key and the node’s encrypted disk, periodic rekeying is advisable.
You must perform the rekeying operation for every node before you can delete the old key from the Tang server.
The following sections provide procedures for rekeying and deleting old keys.
19.3.1. Backing up keys for a Tang server
The Tang server uses /usr/libexec/tangd-keygen to generate new keys and stores them in the /var/db/tang directory by default. To recover the Tang server in the event of a failure, back up this directory. The keys are sensitive and because they are able to perform the boot disk decryption of all hosts that have used them, the keys must be protected accordingly.
Procedure
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Copy the backup key from the
/var/db/tangdirectory to the temp directory from which you can restore the key.
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