fix: negative confDepth bug in verifier (#131)

* fix: negative confDepth bug in verifier

* fix: lint

server/config.go

@@ -203,7 +203,15 @@ func ReadConfig(ctx *cli.Context) Config {
 		FallbackTargets:        ctx.StringSlice(FallbackTargets),
 		CacheTargets:           ctx.StringSlice(CacheTargets),
 	}
-	cfg.ClientConfig.WaitForFinalization = (cfg.EthConfirmationDepth < 0)
+	// the eigenda client can only wait for 0 confirmations or finality
+	// the da-proxy has a more fine-grained notion of confirmation depth
+	// we use -1 to let the da client wait for finality, and then need to set the confirmation depth
+	// for the da-proxy to 0 (because negative confirmation depth doesn't mean anything and leads to errors)
+	// TODO: should the eigenda-client implement this feature for us instead?
+	if cfg.EthConfirmationDepth < 0 {
+		cfg.ClientConfig.WaitForFinalization = true
+		cfg.EthConfirmationDepth = 0
+	}
 
 	return cfg
 }
@@ -457,7 +465,7 @@ func CLIFlags() []cli.Flag {
 		},
 		&cli.Int64Flag{
 			Name:    EthConfirmationDepthFlagName,
-			Usage:   "The number of Ethereum blocks of confirmation that the DA batch submission tx must have before it is assumed by the proxy to be final. The value of `0` indicates that the proxy shouldn't wait for any confirmations.",
+			Usage:   "The number of Ethereum blocks to wait before considering a submitted blob's DA batch submission confirmed. `0` means wait for inclusion only. `-1` means wait for finality.",
 			EnvVars: prefixEnvVars("ETH_CONFIRMATION_DEPTH"),
 			Value:   -1,
 		},

verify/cert.go

@@ -50,9 +50,10 @@ func NewCertVerifier(cfg *Config, l log.Logger) (*CertVerifier, error) {
 }
 
 // verifies on-chain batch ID for equivalence to certificate batch header fields
-func (cv *CertVerifier) VerifyBatch(header *binding.IEigenDAServiceManagerBatchHeader,
-	id uint32, recordHash [32]byte, confirmationNumber uint32) error {
-	blockNumber, err := cv.getContextBlock()
+func (cv *CertVerifier) VerifyBatch(
+	header *binding.IEigenDAServiceManagerBatchHeader, id uint32, recordHash [32]byte, confirmationNumber uint32,
+) error {
+	blockNumber, err := cv.getConfDeepBlockNumber()
 	if err != nil {
 		return err
 	}
@@ -103,19 +104,10 @@ func (cv *CertVerifier) VerifyMerkleProof(inclusionProof []byte, root []byte,
 }
 
 // fetches a block number provided a subtraction of a user defined conf depth from latest block
-func (cv *CertVerifier) getContextBlock() (*big.Int, error) {
-	var blockNumber *big.Int
-	blockHeader, err := cv.ethClient.BlockByNumber(context.Background(), nil)
+func (cv *CertVerifier) getConfDeepBlockNumber() (*big.Int, error) {
+	blockNumber, err := cv.ethClient.BlockNumber(context.Background())
 	if err != nil {
-		return nil, err
-	}
-
-	if cv.ethConfirmationDepth == 0 {
-		return blockHeader.Number(), nil
+		return nil, fmt.Errorf("failed to get latest block number: %w", err)
 	}
-
-	blockNumber = new(big.Int)
-	blockNumber.Sub(blockHeader.Number(), big.NewInt(int64(cv.ethConfirmationDepth-1))) // #nosec G115
-
-	return blockNumber, nil
+	return new(big.Int).SetUint64(max(blockNumber-cv.ethConfirmationDepth, 0)), nil
 }

verify/verifier.go

@@ -12,7 +12,7 @@ import (
 
 	"github.com/Layr-Labs/eigenda/api/grpc/common"
 	"github.com/Layr-Labs/eigenda/encoding/kzg"
-	"github.com/Layr-Labs/eigenda/encoding/kzg/verifier"
+	kzgverifier "github.com/Layr-Labs/eigenda/encoding/kzg/verifier"
 	"github.com/Layr-Labs/eigenda/encoding/rs"
 )
 
@@ -26,7 +26,7 @@ type Config struct {
 
 type Verifier struct {
 	verifyCert  bool
-	kzgVerifier *verifier.Verifier
+	kzgVerifier *kzgverifier.Verifier
 	cv          *CertVerifier
 }
 
@@ -41,7 +41,7 @@ func NewVerifier(cfg *Config, l log.Logger) (*Verifier, error) {
 		}
 	}
 
-	kzgVerifier, err := verifier.NewVerifier(cfg.KzgConfig, false)
+	kzgVerifier, err := kzgverifier.NewVerifier(cfg.KzgConfig, false)
 	if err != nil {
 		return nil, err
 	}