Add poolId validation (#154)

zkBob · Jan 24, 2023 · c390321 · c390321
1 parent e7bf186
commit c390321
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/zp-relayer/pool.ts b/zp-relayer/pool.ts
@@ -73,6 +73,7 @@ class Pool {
   public state: PoolState
   public optimisticState: PoolState
   public denominator: BN = toBN(1)
+  public poolId: BN = toBN(0)
   public isInitialized = false
 
   constructor() {
@@ -105,6 +106,8 @@ class Pool {
     if (this.isInitialized) return
 
     this.denominator = toBN(await this.PoolInstance.methods.denominator().call())
+    this.poolId = toBN(await this.PoolInstance.methods.pool_id().call())
+
     await this.syncState(config.startBlock)
     this.isInitialized = true
   }

diff --git a/zp-relayer/validateTx.ts b/zp-relayer/validateTx.ts
@@ -196,7 +196,7 @@ async function getRecoveredAddress(
   return recoveredAddress
 }
 
-async function checkRoot(proofIndex: BN, proofRoot: string, state: PoolState) {
+function checkRoot(proofIndex: BN, proofRoot: string, state: PoolState) {
   const index = proofIndex.toNumber()
 
   const stateRoot = state.getMerkleRootAt(index)
@@ -207,6 +207,13 @@ async function checkRoot(proofIndex: BN, proofRoot: string, state: PoolState) {
   return null
 }
 
+function checkPoolId(deltaPoolId: BN, contractPoolId: BN) {
+  if (deltaPoolId.eq(contractPoolId)) {
+    return null
+  }
+  return new TxValidationError(`Incorrect poolId: given ${deltaPoolId}, expected ${contractPoolId}`)
+}
+
 async function checkScreener(address: string, traceId?: string) {
   if (config.screenerUrl === null || config.screenerToken === null) {
     return null
@@ -259,6 +266,7 @@ export async function validateTx(
     fee.toString(10)
   )
 
+  await checkAssertion(() => checkPoolId(delta.poolId, pool.poolId))
   await checkAssertion(() => checkRoot(delta.transferIndex, root, pool.optimisticState))
   await checkAssertion(() => checkNullifier(nullifier, pool.state.nullifiers))
   await checkAssertion(() => checkNullifier(nullifier, pool.optimisticState.nullifiers))