exposed proof-of-possession methods (#186)

Needed for matter-labs/zksync-era#2684
Also upgraded logging of attestation votes.

---------

Co-authored-by: Akosh Farkash <[email protected]>

node/actors/network/src/gossip/attestation/mod.rs

@@ -97,7 +97,11 @@ impl State {
         }
         // Verify signature only after checking all the other preconditions.
         vote.verify().context("verify")?;
-        tracing::info!("collected vote with weight {weight} from {:?}", vote.key);
+        tracing::info!(
+            "collected vote for {:?} with weight {weight} from {:?}",
+            vote.msg.number,
+            vote.key
+        );
         self.votes.insert(vote.key.clone(), vote);
         self.total_weight += weight;
         Ok(())

node/libs/crypto/src/bls12_381/mod.rs

@@ -55,7 +55,6 @@ impl SecretKey {
     /// Produces a proof of possession for the public key corresponding to this [`SecretKey`]
     pub fn sign_pop(&self) -> ProofOfPossession {
         let msg = self.public().encode();
-
         ProofOfPossession(self.0.sign(&msg, DST_POP, &[]))
     }
 

node/libs/roles/src/validator/keys/secret_key.rs

@@ -1,4 +1,4 @@
-use super::{PublicKey, Signature};
+use super::{ProofOfPossession, PublicKey, Signature};
 use crate::validator::messages::{Msg, MsgHash, Signed};
 use std::{fmt, sync::Arc};
 use zksync_consensus_crypto::{bls12_381, ByteFmt, Text, TextFmt};
@@ -35,6 +35,11 @@ impl SecretKey {
     pub fn sign_hash(&self, msg_hash: &MsgHash) -> Signature {
         Signature(self.0.sign(&ByteFmt::encode(msg_hash)))
     }
+
+    /// Sign a proof of possession.
+    pub fn sign_pop(&self) -> ProofOfPossession {
+        ProofOfPossession(self.0.sign_pop())
+    }
 }
 
 impl ByteFmt for SecretKey {

node/libs/roles/src/validator/keys/signature.rs

@@ -25,7 +25,7 @@ pub struct ProofOfPossession(pub(crate) bls12_381::ProofOfPossession);
 
 impl ProofOfPossession {
     /// Verifies the proof against the public key.
-    pub fn verify(&self, pk: PublicKey) -> anyhow::Result<()> {
+    pub fn verify(&self, pk: &PublicKey) -> anyhow::Result<()> {
         self.0.verify(&pk.0)
     }
 }