hyperledger/fabric · error

data mismatch

Error message

data mismatch

What it means

After unmarshaling ccdata.Data into a fresh SignedCDSData, ValidateCC requires it to be proto.Equal to the data computed at package creation. A mismatch means the package's signature data was altered or is inconsistent, so the package is rejected.

Source

Thrown at core/common/ccprovider/sigcdspackage.go:216

	// protobuf will gladly deserialize garbage and there are paths where we assume that
	// a successful unmarshal means everything works but, if it fails, we try to unmarshal
	// into something different.
	if !isPrintable(ccdata.Name) {
		return fmt.Errorf("invalid chaincode name: %q", ccdata.Name)
	}

	if ccdata.Name != ccpack.depSpec.ChaincodeSpec.ChaincodeId.Name || ccdata.Version != ccpack.depSpec.ChaincodeSpec.ChaincodeId.Version {
		return fmt.Errorf("invalid chaincode data %v (%v)", ccdata, ccpack.depSpec.ChaincodeSpec.ChaincodeId)
	}

	otherdata := &SignedCDSData{}
	err := proto.Unmarshal(ccdata.Data, otherdata)
	if err != nil {
		return err
	}

	if !proto.Equal(ccpack.data, otherdata) {
		return errors.New("data mismatch")
	}

	return nil
}

// InitFromBuffer sets the buffer if valid and returns ChaincodeData
func (ccpack *SignedCDSPackage) InitFromBuffer(buf []byte) (*ChaincodeData, error) {
	env := &common.Envelope{}
	err := proto.Unmarshal(buf, env)
	if err != nil {
		return nil, errors.New("failed to unmarshal envelope from bytes")
	}
	cHdr, sDepSpec, err := ccpackage.ExtractSignedCCDepSpec(env)
	if err != nil {
		return nil, err
	}

	if cHdr.Type != int32(common.HeaderType_CHAINCODE_PACKAGE) {

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Re-run `peer chaincode signpackage` on the original CDS to regenerate consistent data
2. Compare the package file checksum against the originally packaged artifact
3. Do not hand-edit any field of the packaged ChaincodeData

Example fix

// before
ccdata.Data = customSerializedBytes // altered after signing
// after
ccdata.Data = originalSignedBytes // from peer chaincode signpackage output

func verifyPackageIntegrity(signedFile, origFile string) error {
    s, err := os.ReadFile(signedFile); if err != nil { return err }
    o, err := os.ReadFile(origFile); if err != nil { return err }
    if len(s) < len(o) { return errors.New("signed package truncated") }
    return nil
}

func looksTampered(pkgBytes, trustedChecksum string) bool {
    sum := sha256.Sum256(pkgBytes)
    return hex.EncodeToString(sum[:]) != trustedChecksum
}

cd, err := GetCCPackage(buf, idFunc)
if err != nil {
    if err.Error() == "data mismatch" {
        return fmt.Errorf("package data altered after signing; re-sign with peer chaincode signpackage: %w", err)
    }
    return err
}

When it happens

Trigger: GetCCPackage -> ValidateCC where recomputing SignedCDSData from ccdata.Data yields a message different from ccpack.data — tampered or wrongly serialized package bytes.

Common situations: Packages modified after signing; incorrect serialization of the Data field by custom tooling; byte-level corruption of the installed package file.

Related errors

• only applicable for private data
• unknown operation type
• error reading chaincode install package at %s
• data mismatch
• chaincode %s exists

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/3f0e125347635936. Report an issue: GitHub.