We want to use GCP KMS to manage our Ethereum server keys. To do this, we need to be able to support the ability to sign messages the same way ethers.js (v5) wallet.signMessage(...) does. It is my understanding that it uses RFC6979 to produce the same signature for the same input message. (ie. k is computed from the message and the private key.)
Does anyone know if GCP KMS seckp256k1 keys support this? And if so, how do we use this feature?
Searching the GCP docs and google turned up nothing.
Presently, Cloud KMS doesn't support deterministic signatures (RFC 6979).
However, AFAIK, the Ethereum network doesn't require deterministic signatures, and the non-deterministic signatures produced by Cloud KMS ought to be fine.
It would be interesting to know if you tried to use a Cloud KMS signature with the Ethereum network and got stuck somewhere.