Timestamping commitments

src/app.rs

@@ -106,7 +106,7 @@ pub struct InnerApp {
 
 #[orga]
 impl InnerApp {
-    pub const CONSENSUS_VERSION: u8 = 6;
+    pub const CONSENSUS_VERSION: u8 = 7;
 
     #[cfg(feature = "full")]
     fn configure_faucets(&mut self) -> Result<()> {
@@ -495,7 +495,7 @@ mod abci {
             };
             let offline_signers = self
                 .bitcoin
-                .begin_block_step(external_outputs.into_iter().map(Ok))?;
+                .begin_block_step(external_outputs.into_iter().map(Ok), ctx.hash.clone())?;
             for cons_key in offline_signers {
                 let address = self.staking.address_by_consensus_key(cons_key)?.unwrap();
                 self.staking.punish_downtime(address)?;

src/bitcoin/checkpoint.rs

@@ -921,6 +921,7 @@ impl<'a> BuildingCheckpointMut<'a> {
         nbtc_accounts: &Accounts<Nbtc>,
         recovery_scripts: &Map<orga::coins::Address, Adapter<bitcoin::Script>>,
         external_outputs: impl Iterator<Item = Result<bitcoin::TxOut>>,
+        timestamping_commitment: Vec<u8>,
         config: &Config,
     ) -> Result<BuildingAdvanceRes> {
         self.0.status = CheckpointStatus::Signing;
@@ -933,6 +934,11 @@ impl<'a> BuildingCheckpointMut<'a> {
                 .output_script(&[0u8], config.sigset_threshold)?,
         };
 
+        let timestamping_commitment_out = bitcoin::TxOut {
+            value: 0,
+            script_pubkey: bitcoin::Script::new_op_return(&timestamping_commitment),
+        };
+
         let fee_rate = self.fee_rate;
 
         let mut checkpoint_batch = self
@@ -942,6 +948,9 @@ impl<'a> BuildingCheckpointMut<'a> {
             .unwrap();
         let mut checkpoint_tx = checkpoint_batch.get_mut(0)?.unwrap();
 
+        checkpoint_tx
+            .output
+            .push_front(Adapter::new(timestamping_commitment_out))?;
         checkpoint_tx.output.push_front(Adapter::new(reserve_out))?;
 
         let mut excess_inputs = vec![];
@@ -1236,6 +1245,7 @@ impl CheckpointQueue {
     }
 
     #[cfg(feature = "full")]
+    #[allow(clippy::too_many_arguments)]
     pub fn maybe_step(
         &mut self,
         sig_keys: &Map<ConsensusKey, Xpub>,
@@ -1244,6 +1254,7 @@ impl CheckpointQueue {
         external_outputs: impl Iterator<Item = Result<bitcoin::TxOut>>,
         btc_height: u32,
         should_allow_deposits: bool,
+        timestamping_commitment: Vec<u8>,
     ) -> Result<bool> {
         if !self.should_push(sig_keys)? {
             return Ok(false);
@@ -1266,6 +1277,7 @@ impl CheckpointQueue {
                     nbtc_accounts,
                     recovery_scripts,
                     external_outputs,
+                    timestamping_commitment,
                     &config,
                 )?;
 
@@ -1756,6 +1768,7 @@ mod test {
                     .into_iter(),
                     btc_height,
                     true,
+                    vec![1, 2, 3],
                 )
                 .unwrap();
         };

src/bitcoin/mod.rs

@@ -729,6 +729,7 @@ impl Bitcoin {
     pub fn begin_block_step(
         &mut self,
         external_outputs: impl Iterator<Item = Result<bitcoin::TxOut>>,
+        timestamping_commitment: Vec<u8>,
     ) -> Result<Vec<ConsensusKey>> {
         let has_completed_cp = if let Err(Error::Orga(OrgaError::App(err))) =
             self.checkpoints.last_completed_index()
@@ -757,6 +758,7 @@ impl Bitcoin {
                 external_outputs,
                 self.headers.height()?,
                 !reached_capacity_limit,
+                timestamping_commitment,
             )
             .map_err(|err| OrgaError::App(err.to_string()))?;
 
@@ -1095,7 +1097,8 @@ mod tests {
         let maybe_step = || {
             let mut btc = btc.borrow_mut();
 
-            btc.begin_block_step(vec![].into_iter()).unwrap();
+            btc.begin_block_step(vec![].into_iter(), vec![1, 2, 3])
+                .unwrap();
         };
 
         set_time(0);