This commit adds a new method `UpdateKey` to the KMS
interface.
The purpose of `UpdateKey` is to re-wrap an encrypted
data key (the key generated & encrypted with a master key by e.g.
Vault).
For example, consider Vault with a master key ID: `master-key-1`
and an encrypted data key `E(dk)` for a particular object. The
data key `dk` has been generated randomly when the object was created.
Now, the KMS operator may "rotate" the master key `master-key-1`.
However, the KMS cannot forget the "old" value of that master key
since there is still an object that requires `dk`, and therefore,
the `D(E(dk))`.
With the `UpdateKey` method call MinIO can ask the KMS to decrypt
`E(dk)` with the old key (internally) and re-encrypted `dk` with
the new master key value: `E'(dk)`.
However, this operation only works for the same master key ID.
When rotating the data key (replacing it with a new one) then
we perform a `UnsealKey` operation with the 1st master key ID
and then a `GenerateKey` operation with the 2nd master key ID.
This commit also updates the KMS documentation and removes
the `encrypt` policy entry (we don't use `encrypt`) and
add a policy entry for `rewarp`.
- Current implementation was spawning renewer goroutines
without waiting for the lease duration to end. Remove vault renewer
and call vault.RenewToken directly and manage reauthentication if
lease expired.
This commit fixes a nil pointer dereference issue
that can occur when the Vault KMS returns e.g. a 404
with an empty HTTP response. The Vault client SDK
does not treat that as error and returns nil for
the error and the secret.
Further it simplifies the token renewal and
re-authentication mechanism by using a single
background go-routine.
The control-flow of Vault authentications looks
like this:
1. `authenticate()`: Initial login and start of background job
2. Background job starts a `vault.Renewer` to renew the token
3. a) If this succeeds the token gets updated
b) If this fails the background job tries to login again
4. If the login in 3b. succeeded goto 2. If it fails
goto 3b.
This refactors the vault configuration by moving the
vault-related environment variables to `environment.go`
(Other ENV should follow in the future to have a central
place for adding / handling ENV instead of magic constants
and handling across different files)
Further this commit adds master-key SSE-S3 support.
The operator can specify a SSE-S3 master key using
`MINIO_SSE_MASTER_KEY` which will be used as master key
to derive and encrypt per-object keys for SSE-S3
requests.
This commit is also a pre-condition for SSE-S3
auto-encyption support.
Fixes#6329
This commit renames the env variable for vault namespaces
such that it begins with `MINIO_SSE_`. This is the prefix
for all Minio SSE related env. variables (like KMS).
Add support for sse-s3 encryption with vault as KMS.
Also refactoring code to make use of headers and functions defined in
crypto package and clean up duplicated code.
