Deauthenticate offline validators (#354)

* Expose helper functions API from the bioauth pallet

* Shash the bioauth when node is detected to be offline

Author: MOZGIII

Cargo.lock

@@ -64,6 +64,7 @@ sp-inherents = { default-features = false, git = "https://github.com/humanode-ne
 sp-offchain = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
 sp-runtime = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
 sp-session = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
+sp-staking = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
 sp-std = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
 sp-transaction-pool = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
 sp-version = { default-features = false, git = "https://github.com/humanode-network/substrate", branch = "master" }
@@ -125,6 +126,7 @@ std = [
   "sp-offchain/std",
   "sp-runtime/std",
   "sp-session/std",
+  "sp-staking/std",
   "sp-std/std",
   "sp-transaction-pool/std",
   "sp-version/std",

crates/humanode-runtime/Cargo.toml

@@ -584,12 +584,45 @@ parameter_types! {
     pub const MaxPeerDataEncodingSize: u32 = MAX_PEER_DATA_ENCODING_SIZE;
 }
 
+pub struct ImOnlineSlasher;
+
+impl
+    sp_staking::offence::ReportOffence<
+        AccountId,
+        pallet_im_online::IdentificationTuple<Runtime>,
+        pallet_im_online::UnresponsivenessOffence<pallet_im_online::IdentificationTuple<Runtime>>,
+    > for ImOnlineSlasher
+{
+    fn report_offence(
+        _reporters: Vec<AccountId>,
+        offence: pallet_im_online::UnresponsivenessOffence<
+            pallet_im_online::IdentificationTuple<Runtime>,
+        >,
+    ) -> Result<(), sp_staking::offence::OffenceError> {
+        for offender in offence.offenders {
+            Bioauth::deauthenticate(&offender.0);
+        }
+        Ok(())
+    }
+
+    fn is_known_offence(
+        _offenders: &[pallet_im_online::IdentificationTuple<Runtime>],
+        _time_slot: &<pallet_im_online::UnresponsivenessOffence<
+            pallet_im_online::IdentificationTuple<Runtime>,
+        > as sp_staking::offence::Offence<
+            pallet_im_online::IdentificationTuple<Runtime>,
+        >>::TimeSlot,
+    ) -> bool {
+        unreachable!("ImOnline will never call `is_known_offence`")
+    }
+}
+
 impl pallet_im_online::Config for Runtime {
     type AuthorityId = ImOnlineId;
     type Event = Event;
     type NextSessionRotation = Babe;
     type ValidatorSet = Historical;
-    type ReportUnresponsiveness = ();
+    type ReportUnresponsiveness = ImOnlineSlasher;
     type UnsignedPriority = ImOnlineUnsignedPriority;
     type WeightInfo = pallet_im_online::weights::SubstrateWeight<Runtime>;
     type MaxKeys = MaxKeys;

crates/humanode-runtime/src/lib.rs

@@ -396,6 +396,29 @@ pub mod pallet {
         Ok(())
     }
 
+    /// Public API the pallet exposes to the runtime.
+    impl<T: Config> Pallet<T> {
+        pub fn is_authenticated(public_key: &<T as Config>::ValidatorPublicKey) -> bool {
+            ActiveAuthentications::<T>::get()
+                .iter()
+                .any(|authentication| &authentication.public_key == public_key)
+        }
+
+        pub fn deauthenticate(public_key: &<T as Config>::ValidatorPublicKey) -> bool {
+            ActiveAuthentications::<T>::mutate(|active_authentications| {
+                let mut removed = false;
+                active_authentications.retain(|authentication| {
+                    if &authentication.public_key == public_key {
+                        removed = true;
+                        return false;
+                    }
+                    true
+                });
+                removed
+            })
+        }
+    }
+
     /// Dispatchable functions allow users to interact with the pallet and invoke state changes.
     /// These functions materialize as "extrinsics", which are often compared to transactions.
     /// Dispatchable functions must be annotated with a weight and must return