BlockDataHashStructure width only supported at MaxUint32 in

Error message

BlockDataHashStructure width only supported at MaxUint32 in this version

What it means

The BlockDataHashingStructure config value specifies how block data elements are hashed. This Fabric version only supports a width of math.MaxUint32 (hashing all elements together), and validateBlockDataHashingStructure rejects any other width. It exists to keep future widths open while today's code enforces exactly one value.

Source

Thrown at common/channelconfig/channel.go:214

	return nil
}

func (cc *ChannelConfig) validateHashingAlgorithm() error {
	switch cc.protos.HashingAlgorithm.Name {
	case bccsp.SHA256:
		cc.hashingAlgorithm = util.ComputeSHA256
	case bccsp.SHA3_256:
		cc.hashingAlgorithm = util.ComputeSHA3256
	default:
		return fmt.Errorf("Unknown hashing algorithm type: %s", cc.protos.HashingAlgorithm.Name)
	}

	return nil
}

func (cc *ChannelConfig) validateBlockDataHashingStructure() error {
	if cc.protos.BlockDataHashingStructure.Width != math.MaxUint32 {
		return fmt.Errorf("BlockDataHashStructure width only supported at MaxUint32 in this version")
	}
	return nil
}

func (cc *ChannelConfig) validateOrdererAddresses() error {
	if len(cc.protos.OrdererAddresses.Addresses) == 0 {
		return fmt.Errorf("Must set some OrdererAddresses")
	}
	return nil
}

func (cc *ChannelConfig) validateNoOrdererAddresses() error {
	if len(cc.protos.OrdererAddresses.Addresses) > 0 {
		return fmt.Errorf("global OrdererAddresses are not allowed with V3_0 capability, use org specific addresses only")
	}
	return nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

Set Width to math.MaxUint32 (4294967295) in the BlockDataHashingStructure config value
Regenerate the config with configtxgen, which emits the correct default
In tests, initialize the struct explicitly: &cb.BlockDataHashingStructure{Width: math.MaxUint32}

Example fix

// before
bds := &cb.BlockDataHashingStructure{} // Width == 0 -> error

// after
bds := &cb.BlockDataHashingStructure{Width: math.MaxUint32}

Defensive patterns

Strategy: validation

Validate before calling

if blockDataHash != nil && blockDataHash.Width != math.MaxUint32 {
    return errors.New("BlockDataHashingStructure.Width must be math.MaxUint32")
}

Try / catch

cc, err := channelconfig.NewChannelConfig(channelGroup, bccsp)
if err != nil {
    if strings.Contains(err.Error(), "BlockDataHashStructure width") {
        return fmt.Errorf("fix Width to math.MaxUint32 and retry")
    }
    return err
}

Prevention

Always initialize BlockDataHashingStructure with Width: math.MaxUint32 in tests/tools
Use configtxgen-generated configs which emit the supported width
Treat any non-MaxUint32 width as invalid before submitting updates

When it happens

Trigger: The BlockDataHashingStructure proto in the channel group has Width != 4294967295 — e.g. Width left at the default 0 because the value was constructed by hand, or a config produced by tooling that emits a concrete count.

Common situations: Building cb.ConfigValue in tests with &cb.BlockDataHashingStructure{} (Width 0); older/custom tooling emitting a different width; manual proto construction omitting the field.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/76d68d775d82cffc. Report an issue: GitHub.