Update the on-disk format for the root key so that it's wrapped with a unique
per-key/per-server key encryption key. This is a bit of security theatre for the
current implementation, but it uses `go-kms-wrapping` as the interface for
wrapping the key. This provides a shim for future support of external KMS such
as cloud provider APIs or Vault transit encryption.
* Removes the JSON serialization extension we had on the `RootKey` struct; this
struct is now only used for key replication and not for disk serialization, so
we don't need this helper.
* Creates a helper for generating cryptographically random slices of bytes that
properly accounts for short reads from the source.
* No observable functional changes outside of the on-disk format, so there are
no test updates.
When the `Full` flag is passed for key rotation, we kick off a core
job to decrypt and re-encrypt all the secure variables so that they
use the new key.
* SV: CAS
* Implement Check and Set for Delete and Upsert
* Reading the conflict from the state store
* Update endpoint for new error text
* Updated HTTP api tests
* Conflicts to the HTTP api
* SV: structs: Update SV time to UnixNanos
* update mock to UnixNano; refactor
* SV: encrypter: quote KeyID in error
* SV: mock: add mock for namespace w/ SV
The `Encrypt` method generates an appropriately-sized nonce and uses
that buffer as the prefix for the ciphertext. This keeps the
ciphertext and nonce together for decryption, and reuses the buffer as
much as possible without presenting the temptation to reuse the
cleartext buffer owned by the caller.
We include the key ID as the "additional data" field that's used as an
extra input to the authentication signature, to provide additional
protection that a ciphertext originated with that key.
Refactors the locking for the keyring so that the public methods are
generally (with one commented exception) responsible for taking the
lock and then inner methods are assumed locked.
This PR splits SecureVariable into SecureVariableDecrypted and
SecureVariableEncrypted in order to use the type system to help
verify that cleartext secret material is not committed to file.
* Make Encrypt function return KeyID
* Split SecureVariable
Co-authored-by: Tim Gross <tgross@hashicorp.com>
In order to support implicit ACL policies for tasks to get their own
secrets, each task would need to have its own ACL token. This would
add extra raft overhead as well as new garbage collection jobs for
cleaning up task-specific ACL tokens. Instead, Nomad will create a
workload Identity Claim for each task.
An Identity Claim is a JSON Web Token (JWT) signed by the server’s
private key and attached to an Allocation at the time a plan is
applied. The encoded JWT can be submitted as the X-Nomad-Token header
to replace ACL token secret IDs for the RPCs that support identity
claims.
Whenever a key is is added to a server’s keyring, it will use the key
as the seed for a Ed25519 public-private private keypair. That keypair
will be used for signing the JWT and for verifying the JWT.
This implementation is a ruthlessly minimal approach to support the
secure variables feature. When a JWT is verified, the allocation ID
will be checked against the Nomad state store, and non-existent or
terminal allocation IDs will cause the validation to be rejected. This
is sufficient to support the secure variables feature at launch
without requiring implementation of a background process to renew
soon-to-expire tokens.
Replication for the secure variables keyring. Because only key
metadata is stored in raft, we need to distribute key material
out-of-band from raft replication. A goroutine runs on each server and
watches for changes to the `RootKeyMeta`. When a new key is received,
attempt to fetch the key from the leader. If the leader doesn't have
the key (which may happen if a key is rotated right before a leader
transition), try to get the key from any peer.
After internal design review, we decided to remove exposing algorithm
choice to the end-user for the initial release. We'll solve nonce
rotation by forcing rotations automatically on key GC (in a core job,
not included in this changeset). Default to AES-256 GCM for the
following criteria:
* faster implementation when hardware acceleration is available
* FIPS compliant
* implementation in pure go
* post-quantum resistance
Also fixed a bug in the decoding from keystore and switched to a
harder-to-misuse encoding method.
This changeset implements the keystore serialization/deserialization:
* Adds a JSON serialization extension for the `RootKey` struct, along with a metadata stub. When we serialize RootKey to the on-disk keystore, we want to base64 encode the key material but also exclude any frequently-changing fields which are stored in raft.
* Implements methods for loading/saving keys to the keystore.
* Implements methods for restoring the whole keystore from disk.
* Wires it all up with the `Keyring` RPC handlers and fixes up any fallout on tests.
Tim Gross