[ZIP-233] Network Sustainability Mechanism: Burning

Cargo.toml

@@ -161,4 +161,4 @@ panic = 'abort'
 codegen-units = 1
 
 [workspace.lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(zcash_unstable, values("zfuture"))'] }
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(zcash_unstable, values("zfuture", "tze", "nsm"))'] }

components/zcash_protocol/Cargo.toml

@@ -47,3 +47,6 @@ test-dependencies = [
 
 ## Exposes support for working with a local consensus (e.g. regtest).
 local-consensus = []
+
+[lints]
+workspace = true

components/zcash_protocol/src/consensus.rs

@@ -494,6 +494,8 @@ const UPGRADES_IN_ORDER: &[NetworkUpgrade] = &[
     NetworkUpgrade::Canopy,
     NetworkUpgrade::Nu5,
     NetworkUpgrade::Nu6,
+    #[cfg(zcash_unstable = "zfuture")]
+    NetworkUpgrade::ZFuture,
 ];
 
 /// The "grace period" defined in [ZIP 212].

devtools/src/bin/inspect/transaction.rs

@@ -31,7 +31,7 @@
     GROTH16_PARAMS, ORCHARD_VK,
 };
 
-#[cfg(zcash_unstable = "zfuture")]
+#[cfg(zcash_unstable = "tze")]
 use zcash_primitives::transaction::components::tze;
 
 pub fn is_coinbase(tx: &Transaction) -> bool {
@@ -148,7 +148,7 @@
     type SaplingAuth = sapling::bundle::Authorized;
     type OrchardAuth = orchard::bundle::Authorized;
 
-    #[cfg(zcash_unstable = "zfuture")]
+    #[cfg(zcash_unstable = "tze")]
     type TzeAuth = tze::Authorized;
 }
 
@@ -211,7 +211,7 @@
             f_transparent,
             (),
             (),
-            #[cfg(zcash_unstable = "zfuture")]
+            #[cfg(zcash_unstable = "tze")]
             (),
         );
         let txid_parts = tx.digest(TxIdDigester);

zcash_client_sqlite/src/wallet.rs

@@ -1656,6 +1656,10 @@
                     tx_data.sprout_bundle().cloned(),
                     tx_data.sapling_bundle().cloned(),
                     tx_data.orchard_bundle().cloned(),
+                    #[cfg(zcash_unstable = "nsm")]
+                    tx_data.burn_amount(),
+                    #[cfg(zcash_unstable = "tze")]
+                    tx_data.tze_bundle().cloned(),
                 )
                 .freeze()
                 .map(|t| (expiry_height, t))

zcash_client_sqlite/src/wallet/init.rs

@@ -819,6 +819,10 @@ mod tests {
                 None,
                 None,
                 None,
+                #[cfg(zcash_unstable = "nsm")]
+                None,
+                #[cfg(zcash_unstable = "tze")]
+                None,
             )
             .freeze()
             .unwrap();

zcash_client_sqlite/src/wallet/init/migrations/tx_retrieval_queue.rs

@@ -218,6 +218,8 @@ mod tests {
             None,
             None,
             None,
+            #[cfg(zcash_unstable = "nsm")] None,
+            #[cfg(zcash_unstable = "tze")] None,
         ));
 
         // Check that we can apply this migration.

zcash_extensions/src/lib.rs

@@ -6,7 +6,7 @@
 // For workspace compilation reasons, we have this crate in the workspace and just leave
 // it empty if `zfuture` is not enabled.
 
-#[cfg(zcash_unstable = "zfuture")]
+#[cfg(zcash_unstable = "tze")]
 pub mod consensus;
-#[cfg(zcash_unstable = "zfuture")]
+#[cfg(zcash_unstable = "tze")]
 pub mod transparent;

zcash_extensions/src/transparent/demo.rs

@@ -672,7 +672,7 @@ mod tests {
             precondition: tze::Precondition::from(0, &Precondition::open(hash_1)),
         };
 
-        let tx_a = TransactionData::from_parts_zfuture(
+        let tx_a = TransactionData::from_parts(
             TxVersion::ZFuture,
             BranchId::ZFuture,
             0,
@@ -681,6 +681,8 @@ mod tests {
             None,
             None,
             None,
+            #[cfg(zcash_unstable = "nsm")]
+            None,
             Some(Bundle {
                 vin: vec![],
                 vout: vec![out_a],
@@ -703,7 +705,7 @@ mod tests {
             precondition: tze::Precondition::from(0, &Precondition::close(hash_2)),
         };
 
-        let tx_b = TransactionData::from_parts_zfuture(
+        let tx_b = TransactionData::from_parts(
             TxVersion::ZFuture,
             BranchId::ZFuture,
             0,
@@ -712,6 +714,8 @@ mod tests {
             None,
             None,
             None,
+            #[cfg(zcash_unstable = "nsm")]
+            None,
             Some(Bundle {
                 vin: vec![in_b],
                 vout: vec![out_b],
@@ -730,7 +734,7 @@ mod tests {
             witness: tze::Witness::from(0, &Witness::close(preimage_2)),
         };
 
-        let tx_c = TransactionData::from_parts_zfuture(
+        let tx_c = TransactionData::from_parts(
             TxVersion::ZFuture,
             BranchId::ZFuture,
             0,

zcash_primitives/Cargo.toml

@@ -137,3 +137,6 @@ harness = false
 
 [badges]
 maintenance = { status = "actively-developed" }
+
+[lints]
+workspace = true

zcash_primitives/src/transaction/builder.rs

@@ -32,6 +32,9 @@
     },
 };
 
+#[cfg(zcash_unstable = "nsm")]
+use zcash_protocol::value::ZatBalance;
+
 #[cfg(feature = "transparent-inputs")]
 use crate::transaction::components::transparent::builder::TransparentInputInfo;
 
@@ -287,6 +290,8 @@
     // derivatives for proving and signing to complete transaction creation.
     sapling_asks: Vec<sapling::keys::SpendAuthorizingKey>,
     orchard_saks: Vec<orchard::keys::SpendAuthorizingKey>,
+    #[cfg(zcash_unstable = "nsm")]
+    burn_amount: Option<NonNegativeAmount>,
     #[cfg(zcash_unstable = "zfuture")]
     tze_builder: TzeBuilder<'a, TransactionData<Unauthorized>>,
     #[cfg(not(zcash_unstable = "zfuture"))]
@@ -372,6 +377,8 @@
             orchard_builder,
             sapling_asks: vec![],
             orchard_saks: Vec::new(),
+            #[cfg(zcash_unstable = "nsm")]
+            burn_amount: None,
             #[cfg(zcash_unstable = "zfuture")]
             tze_builder: TzeBuilder::empty(),
             #[cfg(not(zcash_unstable = "zfuture"))]
@@ -400,6 +407,8 @@
             orchard_builder: self.orchard_builder,
             sapling_asks: self.sapling_asks,
             orchard_saks: self.orchard_saks,
+            #[cfg(zcash_unstable = "nsm")]
+            burn_amount: self.burn_amount,
             tze_builder: self.tze_builder,
             progress_notifier,
         }
@@ -524,6 +533,11 @@
                         .map_err(|_| BalanceError::Overflow)
                 },
             )?,
+            #[cfg(zcash_unstable = "nsm")]
+            -self
+                .burn_amount
+                .map(Into::into)
+                .unwrap_or(ZatBalance::zero()),
             #[cfg(zcash_unstable = "zfuture")]
             self.tze_builder.value_balance()?,
         ];
@@ -631,6 +645,11 @@
             .map_err(FeeError::FeeRule)
     }
 
+    #[cfg(zcash_unstable = "nsm")]
+    pub fn set_burn_amount(&mut self, burn_amount: Option<NonNegativeAmount>) {
+        self.burn_amount = burn_amount;
+    }
+
     /// Builds a transaction from the configured spends and outputs.
     ///
     /// Upon success, returns a tuple containing the final transaction, and the
@@ -743,7 +762,7 @@
             None => (None, orchard::builder::BundleMetadata::empty()),
         };
 
-        #[cfg(zcash_unstable = "zfuture")]
+        #[cfg(zcash_unstable = "tze")]
         let (tze_bundle, tze_signers) = self.tze_builder.build();
 
         let unauthed_tx: TransactionData<Unauthorized> = TransactionData {
@@ -755,7 +774,9 @@
             sprout_bundle: None,
             sapling_bundle,
             orchard_bundle,
-            #[cfg(zcash_unstable = "zfuture")]
+            #[cfg(zcash_unstable = "nsm")]
+            burn_amount: self.burn_amount,
+            #[cfg(zcash_unstable = "tze")]
             tze_bundle,
         };
 
@@ -773,7 +794,7 @@
             )
         });
 
-        #[cfg(zcash_unstable = "zfuture")]
+        #[cfg(zcash_unstable = "tze")]
         let tze_bundle = unauthed_tx
             .tze_bundle
             .clone()
@@ -823,7 +844,9 @@
             sprout_bundle: unauthed_tx.sprout_bundle,
             sapling_bundle,
             orchard_bundle,
-            #[cfg(zcash_unstable = "zfuture")]
+            #[cfg(zcash_unstable = "nsm")]
+            burn_amount: self.burn_amount,
+            #[cfg(zcash_unstable = "tze")]
             tze_bundle,
         };
 
@@ -978,6 +1001,8 @@
             expiry_height: sapling_activation_height + DEFAULT_TX_EXPIRY_DELTA,
             transparent_builder: TransparentBuilder::empty(),
             sapling_builder: None,
+            #[cfg(zcash_unstable = "nsm")]
+            burn_amount: None,
             #[cfg(zcash_unstable = "zfuture")]
             tze_builder: TzeBuilder::empty(),
             #[cfg(not(zcash_unstable = "zfuture"))]
@@ -1139,6 +1164,24 @@
             );
         }
 
+        // Fail if there is only a burn
+        // 0.0005 burned, 0.0001 t-ZEC fee
+        #[cfg(zcash_unstable = "nsm")]
+        {
+            let build_config = BuildConfig::Standard {
+                sapling_anchor: Some(sapling::Anchor::empty_tree()),
+                orchard_anchor: Some(orchard::Anchor::empty_tree()),
+            };
+            let mut builder = Builder::new(TEST_NETWORK, tx_height, build_config);
+            builder.set_burn_amount(Some(NonNegativeAmount::const_from_u64(50000)));
+
+            assert_matches!(
+                builder.mock_build(OsRng),
+                Err(Error::InsufficientFunds(expected)) if expected ==
+                    (NonNegativeAmount::const_from_u64(50000) + MINIMUM_FEE).unwrap().into()
+            );
+        }
+
         let note1 = to.create_note(
             sapling::value::NoteValue::from_raw(59999),
             Rseed::BeforeZip212(jubjub::Fr::random(&mut rng)),
@@ -1179,6 +1222,40 @@
             );
         }
 
+        // Fail if there is insufficient input
+        // 0.0003 z-ZEC out, 0.0002 t-ZEC out, 0.0001 burned, 0.0001 t-ZEC fee, 0.00059999 z-ZEC in
+        #[cfg(zcash_unstable = "nsm")]
+        {
+            let build_config = BuildConfig::Standard {
+                sapling_anchor: Some(witness1.root().into()),
+                orchard_anchor: Some(orchard::Anchor::empty_tree()),
+            };
+            let mut builder = Builder::new(TEST_NETWORK, tx_height, build_config);
+            builder
+                .add_sapling_spend::<Infallible>(&extsk, note1.clone(), witness1.path().unwrap())
+                .unwrap();
+            builder
+                .add_sapling_output::<Infallible>(
+                    ovk,
+                    to,
+                    NonNegativeAmount::const_from_u64(30000),
+                    MemoBytes::empty(),
+                )
+                .unwrap();
+            builder
+                .add_transparent_output(
+                    &TransparentAddress::PublicKeyHash([0; 20]),
+                    NonNegativeAmount::const_from_u64(10000),
+                )
+                .unwrap();
+            #[cfg(zcash_unstable = "nsm")]
+            builder.set_burn_amount(Some(NonNegativeAmount::const_from_u64(10000)));
+            assert_matches!(
+                builder.mock_build(OsRng),
+                Err(Error::InsufficientFunds(expected)) if expected == Amount::const_from_i64(1)
+            );
+        }
+
         let note2 = to.create_note(
             sapling::value::NoteValue::from_raw(1),
             Rseed::BeforeZip212(jubjub::Fr::random(&mut rng)),
@@ -1221,5 +1298,47 @@
                 Ok(res) if res.transaction().fee_paid(|_| Err(BalanceError::Overflow)).unwrap() == Amount::const_from_i64(10_000)
             );
         }
+
+        // Succeeds if there is sufficient input
+        // 0.0003 z-ZEC out, 0.0002 t-ZEC out, 0.0001 t-ZEC fee, 0.0006 z-ZEC in
+        #[cfg(zcash_unstable = "nsm")]
+        {
+            let note1 = to.create_note(
+                sapling::value::NoteValue::from_raw(70000),
+                Rseed::BeforeZip212(jubjub::Fr::random(&mut rng)),
+            );
+            let cmu1 = Node::from_cmu(&note1.cmu());
+            let mut tree = CommitmentTree::<Node, 32>::empty();
+            tree.append(cmu1).unwrap();
+            let witness1 = IncrementalWitness::from_tree(tree.clone());
+
+            let build_config = BuildConfig::Standard {
+                sapling_anchor: Some(witness1.root().into()),
+                orchard_anchor: Some(orchard::Anchor::empty_tree()),
+            };
+            let mut builder = Builder::new(TEST_NETWORK, tx_height, build_config);
+            builder
+                .add_sapling_spend::<Infallible>(&extsk, note1, witness1.path().unwrap())
+                .unwrap();
+            builder
+                .add_sapling_output::<Infallible>(
+                    ovk,
+                    to,
+                    NonNegativeAmount::const_from_u64(30000),
+                    MemoBytes::empty(),
+                )
+                .unwrap();
+            builder
+                .add_transparent_output(
+                    &TransparentAddress::PublicKeyHash([0; 20]),
+                    NonNegativeAmount::const_from_u64(20000),
+                )
+                .unwrap();
+            builder.set_burn_amount(Some(NonNegativeAmount::const_from_u64(10000)));
+            assert_matches!(
+                builder.mock_build(OsRng),
+                Ok(res) if res.transaction().fee_paid(|_| Err(BalanceError::Overflow)).unwrap() == Amount::const_from_i64(10_000)
+            );
+        }
     }
 }