Encryption at Rest
Supported since NATS server version 2.3.0
Note, although this feature is supported, we recommend file system encryption if available.
The NATS server can be configured to encrypt message blocks which includes message headers and payloads. Other metadata files are encrypted as well, such as the stream metadata file and consumer metadata files.
Two choices of ciphers are currently supported:
jetstream : {
cipher: chachapoly
key : "6dYfBV0zzEkR3vxZCNjxmnVh/aIqgid1"
}
It is recommended to provide the encryption key through an environment variable at runtime, such as
$JS_KEY, so it will not be persisted in a file.jetstream : {
cipher: chachapoly
key: $JS_KEY
}
The variable can be exported in the environment or passed when the server starts up.
JS_KEY="mykey" nats-server -c js.conf
Enabling encryption on a server with existing data is supported. Do note that existing unencrypted message blocks will not be re-encrypted, however any new blocks that are stored will be encrypted going forward.
If it is desired to encrypt the existing blocks, the stream can be backed up and restored (which decrypts on backup and then re-encrypts when restoring it).
If encryption was enabled on the server and the server is restarted with a different key or disabled all together, the server will fail to decrypt messages when attempting to load them from the store. If this happens, you’ll see log messages like the following:
Error decrypting our stream metafile: chacha20poly1305: message authentication failed
Note, that this will impact JetStream functionality, but the server will still support core NATS functionality.
It is possible to change the
cipher, however the same key must be used. The server will properly encrypt new message blocks with the new cipher and decrypt existing messages blocks with the existing cipher.Performance considerations: As expected, encryption is likely to decrease performance, but by how much is hard to define. In some performance tests on a MacbookPro 2.8 GHz Intel Core i7 with SSD, we have observed as little as 1% decrease to more than 30%. In addition to CPU cycles required for encryption, the encrypted files may be larger, which results in more data being stored or read.
Last modified 3d ago