feat: Attach Circuit Version and Manifest Identity to VK (ZK-074)

contracts/privacy_pool/src/contract.rs

@@ -10,8 +10,8 @@ use soroban_sdk::{contract, contractimpl, Address, BytesN, Env};
 use crate::core::{admin, deposit, initialize, view, withdraw};
 use crate::types::errors::Error;
 use crate::types::state::{
-    AnalyticsSnapshot, Denomination, PerformanceMetricKind, PoolConfig, PoolId, Proof, PublicInputs,
-    VerifyingKey,
+    AnalyticsSnapshot, Denomination, PerformanceMetricKind, PoolConfig, PoolId, Proof,
+    PublicInputsWithSchema, VerifyingKey,
 };
 
 #[contract]
@@ -58,7 +58,7 @@ impl PrivacyPool {
         env: Env,
         pool_id: PoolId,
         proof: Proof,
-        pub_inputs: PublicInputs,
+        pub_inputs: PublicInputsWithSchema,
     ) -> Result<bool, Error> {
         withdraw::execute(env, pool_id, proof, pub_inputs)
     }

contracts/privacy_pool/src/core/withdraw.rs

@@ -8,42 +8,55 @@ use crate::crypto::verifier;
 use crate::storage::{analytics, config, nullifier};
 use crate::types::errors::Error;
 use crate::types::events::emit_withdraw;
-use crate::types::state::{PoolId, Proof, PublicInputs};
+use crate::types::state::{PoolId, Proof, PublicInputsWithSchema, EXPECTED_WITHDRAW_SCHEMA_VERSION};
 use crate::utils::{address_decoder, validation};
 
+const EXPECTED_CIRCUIT_VERSION: &str = "1.0.0";
+const EXPECTED_MANIFEST_ID: &[u8; 32] = &[0; 32];
+
+
 /// Execute a withdrawal from a specific shielded pool using a ZK proof.
 pub fn execute(
     env: Env,
     pool_id: PoolId,
     proof: Proof,
-    pub_inputs: PublicInputs,
+    pub_inputs_with_schema: PublicInputsWithSchema,
 ) -> Result<bool, Error> {
     // Load and validate pool configuration
     let pool_config = config::load_pool_config(&env, &pool_id)?;
     validation::require_not_paused(&pool_config)?;
 
     let denomination_amount = pool_config.denomination.amount();
+    let pub_inputs = pub_inputs_with_schema.inputs;
+
+    // Step 1: Validate schema version
+    verifier::validate_schema_version(
+        &pub_inputs_with_schema.schema_version,
+        EXPECTED_WITHDRAW_SCHEMA_VERSION,
+    )?;
 
-    // Step 1: Validate root is in pool history
+    // Step 2: Validate root is in pool history
     validation::require_known_root(&env, &pool_id, &pub_inputs.root)?;
 
-    // Step 2: Check nullifier not already spent in this pool
+    // Step 3: Check nullifier not already spent in this pool
     validation::require_nullifier_unspent(&env, &pool_id, &pub_inputs.nullifier_hash)?;
 
-    // Step 2.5: Validate pool-id and denomination binding
+    // Step 3.5: Validate pool-id and denomination binding
     if pub_inputs.pool_id != pool_id.0 {
         return Err(Error::InvalidPoolId);
     }
     if pub_inputs.denomination != pool_config.denomination.encode_as_field(&env) {
         return Err(Error::InvalidDenomination);
     }
 
-    // Step 3: Validate and decode fee
+    // Step 4: Validate and decode fee
     let fee = validation::decode_and_validate_fee(&pub_inputs.fee, denomination_amount)?;
 
-    // Step 4: Verify Groth16 proof for this pool
+    // Step 5: Verify Groth16 proof for this pool
     let vk = config::load_verifying_key(&env, &pool_id)?;
-    let proof_valid = verifier::verify_proof(&env, &vk, &proof, &pub_inputs)?;
+    let manifest_id_bytes = BytesN::from_array(&env, EXPECTED_MANIFEST_ID);
+    let proof_valid =
+        verifier::verify_proof(&env, &vk, &proof, &pub_inputs, EXPECTED_CIRCUIT_VERSION, &manifest_id_bytes)?;
     if !proof_valid {
         return Err(Error::InvalidProof);
     }

contracts/privacy_pool/src/crypto/verifier.rs

@@ -91,7 +91,11 @@ pub fn verify_proof(
     vk: &VerifyingKey,
     proof: &Proof,
     pub_inputs: &PublicInputs,
+    expected_circuit_version: &str,
+    expected_manifest_id: &BytesN<32>,
 ) -> Result<bool, Error> {
+    // Step 0: Validate VK identity
+    validate_vk_identity(vk, expected_circuit_version, expected_manifest_id)?;
     let bn254 = env.crypto().bn254();
 
     // Step 1: Compute vk_x (linear combination of public inputs)
@@ -175,3 +179,33 @@ pub fn validate_schema_version(
 
     Ok(())
 }
+// ──────────────────────────────────────────────────────────────
+// Verifying Key Identity Validation
+// ──────────────────────────────────────────────────────────────
+
+/// Validates the circuit version and manifest ID of the verifying key.
+///
+/// # Arguments
+/// * `vk` - The verifying key to validate
+/// * `expected_circuit_version` - The expected circuit version string
+/// * `expected_manifest_id` - The expected manifest ID
+///
+/// # Returns
+/// * `Ok(())` if the identity matches
+/// * `Err(Error::CircuitVersionMismatch)` if the circuit version does not match
+/// * `Err(Error::ManifestIdMismatch)` if the manifest ID does not match
+pub fn validate_vk_identity(
+    vk: &VerifyingKey,
+    expected_circuit_version: &str,
+    expected_manifest_id: &BytesN<32>,
+) -> Result<(), Error> {
+    let vk_circuit_version = vk.circuit_version.to_string();
+    if vk_circuit_version != expected_circuit_version {
+        return Err(Error::CircuitVersionMismatch);
+    }
+    if vk.manifest_id != *expected_manifest_id {
+        return Err(Error::ManifestIdMismatch);
+    }
+    Ok(())
+}
+

contracts/privacy_pool/src/types/errors.rs

@@ -77,4 +77,8 @@ pub enum Error {
     InvalidSchemaVersion = 80,
     /// Proof schema version does not match expected version
     SchemaVersionMismatch = 81,
+    /// Circuit version in the VK does not match the expected version
+    CircuitVersionMismatch = 82,
+    /// Manifest ID in the VK does not match the expected version
+    ManifestIdMismatch = 83,
 }

contracts/privacy_pool/src/types/state.rs

@@ -181,6 +181,10 @@ pub struct VerifyingKey {
     /// G1 points for public input combination: [IC_0, IC_1, ..., IC_8]
     /// One per public input (pool_id, root, nullifier_hash, recipient, amount, relayer, fee, denomination) + IC_0
     pub gamma_abc_g1: soroban_sdk::Vec<BytesN<64>>,
+    /// Circuit version identifier (e.g., "1.0.0")
+    pub circuit_version: String,
+    /// Manifest identifier (sha256 of the manifest)
+    pub manifest_id: BytesN<32>,
 }
 
 // ──────────────────────────────────────────────────────────────

sdk/src/types.ts

@@ -42,6 +42,7 @@ export interface ZkArtifactManifestCircuit {
   checksum?: string; // Legacy field for compatibility
   name: string;
   backend: string;
+  circuit_version?: string;
   root_depth?: number;
   public_input_schema?: string[];
 }
@@ -53,6 +54,7 @@ export interface ZkArtifactManifestBackend {
 }
 
 export interface ZkArtifactManifest {
+  manifest_id?: string;
   version: number | string;
   backend: string | ZkArtifactManifestBackend;
   circuits: Record<string, ZkArtifactManifestCircuit>;