Add support for deposits with invalid signatures

pkg/tasks/generate_deposits/config.go

@@ -24,6 +24,7 @@ type Config struct {
 	AwaitReceipt          bool   `yaml:"awaitReceipt" json:"awaitReceipt" desc:"Wait for transaction receipts on the execution layer before completing."`
 	FailOnReject          bool   `yaml:"failOnReject" json:"failOnReject" desc:"Fail the task if any deposit transaction is rejected."`
 	AwaitInclusion        bool   `yaml:"awaitInclusion" json:"awaitInclusion" desc:"Wait for deposits to be included in beacon blocks before completing."`
+	InvalidSigPercent     int    `yaml:"invalidSigPercent" json:"invalidSigPercent" desc:"Random percentage (0-100) of deposits to generate with corrupted signatures."`
 
 	DepositTransactionsResultVar string `yaml:"depositTransactionsResultVar" json:"depositTransactionsResultVar" deprecated:"true" desc:"Deprecated: Use task outputs instead."`
 	DepositReceiptsResultVar     string `yaml:"depositReceiptsResultVar" json:"depositReceiptsResultVar" deprecated:"true" desc:"Deprecated: Use task outputs instead."`
@@ -64,5 +65,9 @@ func (c *Config) Validate() error {
 		return errors.New("depositAmount must be > 0")
 	}
 
+	if c.InvalidSigPercent < 0 || c.InvalidSigPercent > 100 {
+		return errors.New("invalidSigPercent must be in range 0-100")
+	}
+
 	return nil
 }

pkg/tasks/generate_deposits/task.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/ecdsa"
+	cryptorand "crypto/rand"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -515,21 +516,8 @@ func (t *Task) generateDeposit(ctx context.Context, accountIdx uint64, onComplet
 		Signature:             common.BLSSignature{},
 	}
 
-	if !t.config.TopUpDeposit {
-		msgRoot := depositData.ToMessage().HashTreeRoot(tree.GetHashFn())
-
-		var secKey hbls.SecretKey
-
-		err := secKey.Deserialize(validatorPrivkey.Marshal())
-		if err != nil {
-			return nil, nil, fmt.Errorf("cannot convert validator priv key")
-		}
-
-		genesis := clientPool.GetConsensusPool().GetBlockCache().GetGenesis()
-		dom := common.ComputeDomain(common.DOMAIN_DEPOSIT, common.Version(genesis.GenesisForkVersion), common.Root{})
-		msg := common.ComputeSigningRoot(msgRoot, dom)
-		sig := secKey.SignHash(msg[:])
-		copy(depositData.Signature[:], sig.Serialize())
+	if err := t.signDepositData(&depositData, validatorPrivkey); err != nil {
+		return nil, nil, err
 	}
 
 	dataRoot := depositData.HashTreeRoot(tree.GetHashFn())
@@ -620,6 +608,56 @@ func (t *Task) generateDeposit(ctx context.Context, accountIdx uint64, onComplet
 	return &pub, tx, nil
 }
 
+func (t *Task) signDepositData(depositData *common.DepositData, validatorPrivkey *e2types.BLSPrivateKey) error {
+	if t.config.TopUpDeposit {
+		return nil
+	}
+
+	useInvalid, err := t.shouldUseInvalidSignature()
+	if err != nil {
+		return err
+	}
+
+	if useInvalid {
+		if _, err := cryptorand.Read(depositData.Signature[:]); err != nil {
+			return fmt.Errorf("failed to generate random invalid signature: %w", err)
+		}
+
+		t.logger.Debugf("generated deposit with invalid (random) signature for pubkey 0x%x", depositData.Pubkey)
+
+		return nil
+	}
+
+	msgRoot := depositData.ToMessage().HashTreeRoot(tree.GetHashFn())
+
+	var secKey hbls.SecretKey
+	if err := secKey.Deserialize(validatorPrivkey.Marshal()); err != nil {
+		return fmt.Errorf("cannot convert validator priv key")
+	}
+
+	clientPool := t.ctx.Scheduler.GetServices().ClientPool()
+	genesis := clientPool.GetConsensusPool().GetBlockCache().GetGenesis()
+	dom := common.ComputeDomain(common.DOMAIN_DEPOSIT, common.Version(genesis.GenesisForkVersion), common.Root{})
+	msg := common.ComputeSigningRoot(msgRoot, dom)
+	sig := secKey.SignHash(msg[:])
+	copy(depositData.Signature[:], sig.Serialize())
+
+	return nil
+}
+
+func (t *Task) shouldUseInvalidSignature() (bool, error) {
+	if t.config.InvalidSigPercent <= 0 {
+		return false, nil
+	}
+
+	var b [1]byte
+	if _, err := cryptorand.Read(b[:]); err != nil {
+		return false, fmt.Errorf("failed to read random byte: %w", err)
+	}
+
+	return int(b[0])%100 < t.config.InvalidSigPercent, nil
+}
+
 func (t *Task) mnemonicToSeed(mnemonic string) (seed []byte, err error) {
 	mnemonic = strings.TrimSpace(mnemonic)
 	if !bip39.IsMnemonicValid(mnemonic) {