vochain fork: refactor ZkCircuits handling

* circuit/config: rename `dev` -> `v0.0.1` and add voceremony as `v1.0.0`
* vochain/app.go: SetZkCircuit during beginBlock
* add config/forks.go
* circuit: add DownloadZkCircuits funcs
  * DownloadZkCircuitsForChainID
  * DownloadDefaultZkCircuit

NewBaseApplication now calls circuit.DownloadDefaultZkCircuit
instead of transactionHandler.LoadZkCircuit

and newTendermint now calls circuit.DownloadZkCircuitsForChainID

config/forks.go

@@ -0,0 +1,33 @@
+package config
+
+// ForksCfg allows applying softforks at specified heights
+type ForksCfg struct {
+	VoceremonyForkBlock uint32
+}
+
+// Forks is a map of chainIDs
+var Forks = map[string]*ForksCfg{
+	"vocdoni/DEV/29": {
+		VoceremonyForkBlock: 180000, // estimated 2023-11-30T23:45:29.095375169Z
+	},
+	"vocdoni/STAGE/9": {
+		VoceremonyForkBlock: 190000, // estimated 2023-12-04T11:25:38.643517797Z
+	},
+	"vocdoni/LTS/1.2": {
+		VoceremonyForkBlock: 350000, // estimated 2023-12-06T05:59:27.529386884Z
+	},
+}
+
+// DefaultZkCircuitVersion is the circuit version used by default
+const DefaultZkCircuitVersion = "v0.0.1"
+
+// VoceremonyForkZkCircuitVersion is the circuit version used after VoceremonyForkBlock
+const VoceremonyForkZkCircuitVersion = "v1.0.0"
+
+// ForksForChainID returns the ForksCfg of chainID, if found, or an empty ForksCfg otherwise
+func ForksForChainID(chainID string) *ForksCfg {
+	if cfg, found := Forks[chainID]; found {
+		return cfg
+	}
+	return &ForksCfg{}
+}

crypto/zk/circuit/circuit.go

@@ -12,6 +12,7 @@ import (
 	"path/filepath"
 	"time"
 
+	"go.vocdoni.io/dvote/config"
 	"go.vocdoni.io/dvote/log"
 )
 
@@ -40,6 +41,26 @@ type ZkCircuit struct {
 	Config          *ZkCircuitConfig
 }
 
+// DownloadDefaultZkCircuit ensures the default circuit is cached locally
+func DownloadDefaultZkCircuit() error {
+	_, err := LoadZkCircuitByTag(config.DefaultZkCircuitVersion)
+	if err != nil {
+		return fmt.Errorf("could not load zk verification keys: %w", err)
+	}
+	return nil
+}
+
+// DownloadZkCircuitsForChainID ensures all circuits needed for chainID are cached locally
+func DownloadZkCircuitsForChainID(chainID string) error {
+	if config.ForksForChainID(chainID).VoceremonyForkBlock > 0 {
+		_, err := LoadZkCircuitByTag(config.VoceremonyForkZkCircuitVersion)
+		if err != nil {
+			return fmt.Errorf("could not load zk verification keys: %w", err)
+		}
+	}
+	return DownloadDefaultZkCircuit()
+}
+
 // LoadZkCircuitByTag gets the circuit configuration associated to the provided
 // tag or gets the default one and load its artifacts to prepare the circuit to
 // be used.

crypto/zk/circuit/config.go

@@ -80,7 +80,7 @@ func (conf *ZkCircuitConfig) SupportsCensusSize(maxCensusSize uint64) bool {
 // the remote and local location of the circuits artifacts and their metadata
 // such as artifacts hash or the number of parameters.
 var CircuitsConfigurations = map[string]*ZkCircuitConfig{
-	"dev": {
+	"v0.0.1": {
 		URI: "https://raw.githubusercontent.com/vocdoni/" +
 			"zk-franchise-proof-circuit/master",
 		CircuitPath:             "artifacts/zkCensus/dev/160",
@@ -92,17 +92,16 @@ var CircuitsConfigurations = map[string]*ZkCircuitConfig{
 		WasmHash:                hexToBytes("0x80a73567f6a4655d4332301efcff4bc5711bb48176d1c71fdb1e48df222ac139"),
 		WasmFilename:            "circuit.wasm",
 	},
-	"prod": {
-		URI: "https://raw.githubusercontent.com/vocdoni/" +
-			"zk-franchise-proof-circuit/master",
-		CircuitPath:             "artifacts/zkCensus/dev/160",
+	"v1.0.0": {
+		URI:                     "https://raw.githubusercontent.com/altergui/zk-voceremony",
+		CircuitPath:             "ceremony/vocdoni-zkcensus-ceremony/results",
 		Levels:                  160, // ZkCircuit number of levels
-		ProvingKeyHash:          hexToBytes("0xe359b256e5e3c78acaccf8dab5dc4bea99a2f07b2a05e935b5ca658c714dea4a"),
-		ProvingKeyFilename:      "proving_key.zkey",
-		VerificationKeyHash:     hexToBytes("0x235e55571812f8e324e73e37e53829db0c4ac8f68469b9b953876127c97b425f"),
-		VerificationKeyFilename: "verification_key.json",
-		WasmHash:                hexToBytes("0x80a73567f6a4655d4332301efcff4bc5711bb48176d1c71fdb1e48df222ac139"),
-		WasmFilename:            "circuit.wasm",
+		ProvingKeyHash:          hexToBytes("0x94f4062db3e43175ac1136f285551d547a177e37b0616a41900a38ed5ec3d478"),
+		ProvingKeyFilename:      "census_proving_key.zkey",
+		VerificationKeyHash:     hexToBytes("0x2a47ff7e511926290fedfa406886944eeb0a3df9021ca26333c0c124c89aa7b0"),
+		VerificationKeyFilename: "census_verification_key.json",
+		WasmHash:                hexToBytes("0xc98133cf4d84ced677549e0d848739f4e80ddf78af678cbc8b95377247a92773"),
+		WasmFilename:            "census.wasm",
 	},
 }
 

vochain/app.go

@@ -136,10 +136,11 @@ func NewBaseApplication(vochainCfg *config.VochainCfg) (*BaseApplication, error)
 		istc,
 		filepath.Join(vochainCfg.DataDir, "txHandler"),
 	)
-	// Load or download the zk verification keys
-	if err := transactionHandler.LoadZkCircuit(circuit.DefaultCircuitConfigurationTag); err != nil {
+
+	if err := circuit.DownloadDefaultZkCircuit(); err != nil {
 		return nil, fmt.Errorf("cannot load zk circuit: %w", err)
 	}
+
 	blockCache, err := lru.New[int64, *tmtypes.Block](32)
 	if err != nil {
 		return nil, err
@@ -260,6 +261,7 @@ func (app *BaseApplication) beginBlock(t time.Time, height uint32) {
 	app.State.Rollback()
 	app.startBlockTimestamp.Store(t.Unix())
 	app.State.SetHeight(height)
+	app.SetZkCircuit()
 	go app.State.CachePurge(height)
 	app.State.OnBeginBlock(vstate.BeginBlock{
 		Height: int64(height),
@@ -352,6 +354,16 @@ func (app *BaseApplication) Genesis() *tmtypes.GenesisDoc {
 	return app.genesisInfo
 }
 
+// SetZkCircuit updates the ZkCircuit if planned at the current height
+func (app *BaseApplication) SetZkCircuit() {
+	if config.ForksForChainID(app.chainID).VoceremonyForkBlock == app.Height() {
+		err := app.TransactionHandler.LoadZkCircuit(config.VoceremonyForkZkCircuitVersion)
+		if err != nil {
+			log.Fatalf("failed to update ZkCircuit on VoceremonyForkBlock: %w", err)
+		}
+	}
+}
+
 // SetCircuitConfigTag sets the current BaseApplication circuit config tag
 // attribute to the provided one and loads the circuit configuration based on
 // it. The available circuit config tags are defined in

vochain/start.go

@@ -12,6 +12,7 @@ import (
 
 	"go.vocdoni.io/dvote/config"
 	"go.vocdoni.io/dvote/crypto/ethereum"
+	"go.vocdoni.io/dvote/crypto/zk/circuit"
 	vocdoniGenesis "go.vocdoni.io/dvote/vochain/genesis"
 
 	tmcfg "github.com/cometbft/cometbft/config"
@@ -275,6 +276,9 @@ func newTendermint(app *BaseApplication,
 	log.Infow("genesis file", "genesis", tconfig.GenesisFile(), "chainID", genesisCID.ChainID)
 	app.SetChainID(genesisCID.ChainID)
 
+	// the chain might need additional ZkCircuits, now that we know the chainID ensure they are downloaded
+	circuit.DownloadZkCircuitsForChainID(genesisCID.ChainID)
+
 	// assign the default tendermint methods
 	app.SetDefaultMethods()
 	node, err := tmnode.NewNode(tconfig,