Request identity v1 implementation

[jackkleeman]

Implements a simple request signing approach using ed25519 jwts. Signed parameters:

• path as aud (which will include service method)
• issue time, expiry time, and not before time - currently +- 60s

The header looks like:

{
  "typ": "JWT",
  "alg": "EdDSA",
  "kid": "publickeyv1_3bQPC1Lsw1PoXFswYssFGUfoDYughmDy5sdY27FobREn"
}

The payload looks like:

{
  "aud": "/discover",
  "exp": 1712249043,
  "iat": 1712248143,
  "nbf": 1712247243
}

The goal of this signing protocol is to prove recent ownership of the private key without requiring mutual TLS. It is not intended to provide strong interception protection, but only client identification; request bodies and headers remain mutable by a MITM attacker. Server-authenticated TLS must still be used to provide interception protection.

A single private key can be given as a local pem file. Public keys in a format like publickeyv1_CVmG1AvSyedeZpwwd3MRGbRu5yFt3QXXEpQJKyigB9A5 are emitted into logs and can be safely included in service code to aid in verification.

Headers:

1. x-restate-jwt-v1 -> the jwt
2. x-restate-signature-scheme -> v1

[igalshilman]

I’ve checked the JWT part, and the tests looks good!

One question about the expiration, is the unit is seconds or milliseconds?

And also, this probably should be a configuration or at least a constant?

I didn’t look into the details of integrating this into the invoker, if you need some feedback there, maybe ping Francesco/Till?

[jackkleeman]

the unit is seconds, i will clarify and make it a constant - dont see any need to config it yet

will ping runtime folks for a wider review. thx

[AhmedSoliman]

Really nice. I left a couple of tiny optional nits but this is good to go.

Great job 👏

[AhmedSoliman]

neat!