implement report_double_vote custom action

Author: HoOngEe

core/src/consensus/mod.rs

@@ -34,6 +34,7 @@ pub use self::solo::Solo;
 pub use self::tendermint::{Tendermint, TendermintParams, TimeGapParams};
 pub use self::validator_set::validator_list::RoundRobinValidator;
 pub use self::validator_set::ValidatorSet;
+pub use self::vote_collector::Message;
 
 use std::fmt;
 use std::sync::{Arc, Weak};

core/src/consensus/solo/mod.rs

@@ -18,16 +18,18 @@ mod params;
 
 use std::sync::Arc;
 
-use ckey::Address;
+use ckey::{Address, Error as KeyError, Public, SchnorrSignature};
 use cstate::{ActionHandler, HitHandler};
 use ctypes::{CommonParams, Header};
+use primitives::H256;
+use rlp::{Decodable, DecoderError, Encodable, RlpStream, UntrustedRlp};
 
 use self::params::SoloParams;
 use super::stake;
 use super::{ConsensusEngine, Seal};
 use crate::block::{ExecutedBlock, IsBlock};
 use crate::codechain_machine::CodeChainMachine;
-use crate::consensus::{EngineError, EngineType};
+use crate::consensus::{EngineError, EngineType, Message};
 use crate::error::Error;
 
 /// A consensus engine which does not provide any consensus mechanism.
@@ -37,14 +39,61 @@ pub struct Solo {
     action_handlers: Vec<Arc<ActionHandler>>,
 }
 
+#[derive(Debug, PartialEq, Eq, Clone, Hash, Default)]
+pub struct SoloMessage {}
+
+impl Encodable for SoloMessage {
+    fn rlp_append(&self, s: &mut RlpStream) {
+        s.append_empty_data();
+    }
+}
+
+impl Decodable for SoloMessage {
+    fn decode(_rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
+        Ok(SoloMessage {})
+    }
+}
+
+impl Message for SoloMessage {
+    type Round = bool;
+
+    fn signature(&self) -> SchnorrSignature {
+        SchnorrSignature::random()
+    }
+
+    fn signer_index(&self) -> usize {
+        Default::default()
+    }
+
+    fn block_hash(&self) -> Option<H256> {
+        None
+    }
+
+    fn round(&self) -> &bool {
+        &false
+    }
+
+    fn height(&self) -> u64 {
+        0
+    }
+
+    fn is_broadcastable(&self) -> bool {
+        false
+    }
+
+    fn verify(&self, _signer_public: &Public) -> Result<bool, KeyError> {
+        Ok(true)
+    }
+}
+
 impl Solo {
     /// Returns new instance of Solo over the given state machine.
     pub fn new(params: SoloParams, machine: CodeChainMachine) -> Self {
         let mut action_handlers: Vec<Arc<ActionHandler>> = Vec::new();
         if params.enable_hit_handler {
             action_handlers.push(Arc::new(HitHandler::new()));
         }
-        action_handlers.push(Arc::new(stake::Stake::new(params.genesis_stakes.clone())));
+        action_handlers.push(Arc::new(stake::Stake::<SoloMessage>::new(params.genesis_stakes.clone())));
 
         Solo {
             params,

core/src/consensus/stake/actions.rs

@@ -14,8 +14,13 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+use std::sync::Arc;
+
 use ccrypto::Blake;
 use ckey::{recover, Address, Signature};
+use client::ConsensusClient;
+use consensus::vote_collector::Message;
+use consensus::ValidatorSet;
 use ctypes::errors::SyntaxError;
 use ctypes::CommonParams;
 use primitives::{Bytes, H256};
@@ -25,10 +30,11 @@ const ACTION_TAG_TRANSFER_CCS: u8 = 1;
 const ACTION_TAG_DELEGATE_CCS: u8 = 2;
 const ACTION_TAG_REVOKE: u8 = 3;
 const ACTION_TAG_SELF_NOMINATE: u8 = 4;
+const ACTION_TAG_REPORT_DOUBLE_VOTE: u8 = 5;
 const ACTION_TAG_CHANGE_PARAMS: u8 = 0xFF;
 
 #[derive(Debug, PartialEq)]
-pub enum Action {
+pub enum Action<M: Message> {
     TransferCCS {
         address: Address,
         quantity: u64,
@@ -50,10 +56,19 @@ pub enum Action {
         params: Box<CommonParams>,
         signatures: Vec<Signature>,
     },
+    ReportDoubleVote {
+        message1: M,
+        message2: M,
+    },
 }
 
-impl Action {
-    pub fn verify(&self, current_params: &CommonParams) -> Result<(), SyntaxError> {
+impl<M: Message> Action<M> {
+    pub fn verify(
+        &self,
+        current_params: &CommonParams,
+        client: Option<Arc<ConsensusClient>>,
+        validators: Option<Arc<ValidatorSet>>,
+    ) -> Result<(), SyntaxError> {
         match self {
             Action::TransferCCS {
                 ..
@@ -89,7 +104,7 @@ impl Action {
                     )))
                 }
                 params.verify().map_err(SyntaxError::InvalidCustomAction)?;
-                let action = Action::ChangeParams {
+                let action = Action::<M>::ChangeParams {
                     metadata_seq: *metadata_seq,
                     params: params.clone(),
                     signatures: vec![],
@@ -102,12 +117,64 @@ impl Action {
                     })?;
                 }
             }
+            Action::ReportDoubleVote {
+                message1,
+                message2,
+            } => {
+                if message1 == message2 {
+                    return Err(SyntaxError::InvalidCustomAction(String::from("Messages are duplicated")))
+                }
+                if message1.round() != message2.round() {
+                    return Err(SyntaxError::InvalidCustomAction(String::from(
+                        "The messages are from two different voting rounds",
+                    )))
+                }
+
+                let signer_idx1 = message1.signer_index();
+                let signer_idx2 = message2.signer_index();
+
+                if signer_idx1 != signer_idx2 {
+                    return Err(SyntaxError::InvalidCustomAction(format!(
+                        "Two messages have different signer indexes: {}, {}",
+                        signer_idx1, signer_idx2
+                    )))
+                }
+
+                assert_eq!(
+                    message1.height(),
+                    message2.height(),
+                    "Heights of both messages must be same because message1.round() == message2.round()"
+                );
+                let signed_block_height = message1.height();
+                let (client, validators) = (
+                    client.expect("Client should be initialized"),
+                    validators.expect("ValidatorSet should be initialized"),
+                );
+                if signed_block_height == 0 {
+                    return Err(SyntaxError::InvalidCustomAction(String::from(
+                        "Double vote on the genesis block does not make sense",
+                    )))
+                }
+                let parent_hash = client
+                    .block_header(&(signed_block_height - 1).into())
+                    .ok_or_else(|| {
+                        SyntaxError::InvalidCustomAction(format!(
+                            "Cannot get header from the height {}",
+                            signed_block_height
+                        ))
+                    })?
+                    .hash();
+                let signer = validators.get(&parent_hash, signer_idx1);
+                if message1.verify(&signer) != Ok(true) || message2.verify(&signer) != Ok(true) {
+                    return Err(SyntaxError::InvalidCustomAction(String::from("Schnorr signature verification fails")))
+                }
+            }
         }
         Ok(())
     }
 }
 
-impl Encodable for Action {
+impl<M: Message> Encodable for Action<M> {
     fn rlp_append(&self, s: &mut RlpStream) {
         match self {
             Action::TransferCCS {
@@ -147,11 +214,17 @@ impl Encodable for Action {
                     s.append(signature);
                 }
             }
+            Action::ReportDoubleVote {
+                message1,
+                message2,
+            } => {
+                s.begin_list(3).append(&ACTION_TAG_REPORT_DOUBLE_VOTE).append(message1).append(message2);
+            }
         };
     }
 }
 
-impl Decodable for Action {
+impl<M: Message> Decodable for Action<M> {
     fn decode(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
         let tag = rlp.val_at(0)?;
         match tag {
@@ -224,13 +297,33 @@ impl Decodable for Action {
                     signatures,
                 })
             }
+            ACTION_TAG_REPORT_DOUBLE_VOTE => {
+                let item_count = rlp.item_count()?;
+                if item_count != 3 {
+                    return Err(DecoderError::RlpIncorrectListLen {
+                        expected: 3,
+                        got: item_count,
+                    })
+                }
+                let message1 = rlp.val_at(1)?;
+                let message2 = rlp.val_at(2)?;
+                Ok(Action::ReportDoubleVote {
+                    message1,
+                    message2,
+                })
+            }
             _ => Err(DecoderError::Custom("Unexpected Tendermint Stake Action Type")),
         }
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+    use ccrypto::blake256;
+    use ckey::sign_schnorr;
+    use client::TestBlockChainClient;
+    use consensus::solo::SoloMessage;
     use rlp::rlp_encode_and_decode_test;
 
     use super::*;
@@ -247,7 +340,7 @@ mod tests {
                 expected: 4,
                 got: 3,
             }),
-            UntrustedRlp::new(&rlp::encode(&action)).as_val::<Action>()
+            UntrustedRlp::new(&rlp::encode(&action)).as_val::<Action>::<_>()
         );
     }