Function sign

rpc/src/auth.rs:70–74

(action: &str, timestamp_secs: u64, signer: &PrivateKeySigner)

        .recover_address_from_msg(message.as_bytes())
        .map_err(|_| RpcError::InvalidSignature)?;

    if &recovered != expected {
        return Err(RpcError::InvalidSignature);
    }

    Ok(())
}