add deposit-merge vk

goas/atomic_asset_transfer/common/src/events.rs

@@ -3,6 +3,7 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Event {
     Spend(Spend),
+    Merge(Merge),
 }
 
 impl Event {
@@ -10,6 +11,7 @@ impl Event {
         // TODO: add variant tag to byte encoding
         match self {
             Event::Spend(spend) => spend.to_bytes().to_vec(),
+            Event::Merge(merge) => merge.to_bytes().to_vec(),
         }
     }
 }
@@ -34,3 +36,18 @@ impl Spend {
         bytes
     }
 }
+
+/// An event that authorizes spending zone funds to merge with other notes
+/// Balancing of the transaction is done in the zone state death constraint
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Merge {
+    pub nf: cl::Nullifier,
+}
+
+impl Merge {
+    pub fn to_bytes(&self) -> [u8; 32] {
+        let mut bytes = [0; 32];
+        bytes.copy_from_slice(self.nf.as_bytes());
+        bytes
+    }
+}

goas/atomic_asset_transfer/proof_statements/src/zone_funds.rs

@@ -19,3 +19,19 @@ pub struct SpendFundsPrivate {
     /// Merkle root of balances in the zone
     pub balances_root: [u8; 32],
 }
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct MergePrivate {
+    // The note we're spending
+    pub funds_note: cl::PartialTxInputWitness,
+    // The zone note that is authorizing the spend
+    pub zone_note: cl::PartialTxOutputWitness,
+    // The event emitted by the zone that authorizes spending this note
+    pub merge_event: common::events::Merge,
+    // Path to the zone output events root
+    pub merge_event_state_path: Vec<cl::merkle::PathNode>,
+    // Merkle root of txs included in the zone
+    pub txs_root: [u8; 32],
+    // Merkle root of balances in the zone
+    pub balances_root: [u8; 32],
+}

goas/atomic_asset_transfer/risc0_proofs/Cargo.toml

@@ -7,5 +7,5 @@ edition = "2021"
 risc0-build = { version = "1.0" }
 
 [package.metadata.risc0]
-methods = ["spend_zone_funds", "zone_state"]
+methods = ["spend_zone_funds", "zone_state", "zone_merge"]
 

goas/atomic_asset_transfer/risc0_proofs/zone_merge/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "zone-merge"
+version = "0.1.0"
+edition = "2021"
+
+[workspace]
+
+[dependencies]
+risc0-zkvm = { version = "1.0", default-features = false, features = ['std'] }
+serde = { version = "1.0", features = ["derive"] }
+cl = { path = "../../../cl/cl" }
+goas_proof_statements = { path = "../../proof_statements" }
+ledger_proof_statements  = { path = "../../../cl/ledger_proof_statements" }
+sha2 = "0.10"
+
+
+[patch.crates-io]
+# add RISC Zero accelerator support for all downstream usages of the following crates.
+sha2 = { git = "https://github.com/risc0/RustCrypto-hashes", tag = "sha2-v0.10.8-risczero.0" }
+crypto-bigint = { git = "https://github.com/risc0/RustCrypto-crypto-bigint", tag = "v0.5.5-risczero.0" }
+curve25519-dalek = { git = "https://github.com/risc0/curve25519-dalek", tag = "curve25519-4.1.2-risczero.0" }

goas/atomic_asset_transfer/risc0_proofs/zone_merge/src/main.rs

@@ -0,0 +1,44 @@
+use cl::{merkle, nullifier::Nullifier, PtxRoot};
+use goas_proof_statements::zone_funds::MergePrivate;
+use ledger_proof_statements::death_constraint::DeathConstraintPublic;
+use risc0_zkvm::guest::env;
+
+fn main() {
+    let MergePrivate {
+        funds_note,
+        zone_note,
+        merge_event,
+        merge_event_state_path,
+        txs_root,
+        balances_root,
+    } = env::read();
+
+    let input_root = funds_note.input_root();
+    let output_root = zone_note.output_root();
+    let nf = Nullifier::new(funds_note.input.nf_sk, funds_note.input.nonce);
+    // check the zone funds note is the one in the spend event
+    assert_eq!(nf, merge_event.nf);
+
+    // ** Assert merge spent event was an output of the correct zone stf **
+    // The zone state field is a merkle tree over:
+    //                  root
+    //              /        \
+    //            io          state
+    //          /   \        /     \
+    //      events   txs   zoneid  balances
+    // We need to check that:
+    // 1) There is a valid path from the spend event to the events root
+    // 2) The zone id matches the one in the current funds note state
+    // 3) The witnesses for merge path, txs and balances allow to calculate the correct root
+    let zone_id = funds_note.input.note.state; // TODO: is there more state?
+    let merge_event_leaf = merkle::leaf(&merge_event.to_bytes());
+    let event_root = merkle::path_root(merge_event_leaf, &merge_event_state_path);
+
+    assert_eq!(
+        merkle::root([event_root, txs_root, zone_id, balances_root]),
+        zone_note.output.note.state
+    );
+    let ptx_root = PtxRoot(merkle::node(input_root, output_root));
+
+    env::commit(&DeathConstraintPublic { ptx_root, nf });
+}

goas/atomic_asset_transfer/risc0_proofs/zone_state/src/main.rs

@@ -94,6 +94,13 @@ fn deposit(
         .checked_add(amount)
         .expect("overflow when depositing");
 
+    // authorize the merge of the zone funds
+    state
+        .output_events
+        .push(events::Event::Merge(events::Merge {
+            nf: Nullifier::new(zone_funds_in.nf_sk, zone_funds_in.nonce),
+        }));
+
     state
 }