hyperledger/fabric · critical

failed generating signature: %s

Error message

failed generating signature: %s

What it means

SignOrPanic invokes signer.Sign(msg); if the signer returns an error (e.g. private key unavailable or unusable) it panics with 'failed generating signature: %s' wrapping the cause. The nil check passed, so a real Signer existed but its cryptographic operation failed.

Source

Thrown at protoutil/commonutils.go:187

	}

	signatureHeader, err := NewSignatureHeader(id)
	if err != nil {
		panic(fmt.Errorf("failed generating a new SignatureHeader: %s", err))
	}

	return signatureHeader
}

// SignOrPanic signs a message and panics on error.
func SignOrPanic(signer identity.Signer, msg []byte) []byte {
	if signer == nil {
		panic(errors.New("invalid signer. cannot be nil"))
	}

	sigma, err := signer.Sign(msg)
	if err != nil {
		panic(fmt.Errorf("failed generating signature: %s", err))
	}
	return sigma
}

// IsConfigBlock validates whenever given block contains configuration
// update transaction
func IsConfigBlock(block *cb.Block) bool {
	if block.Data == nil {
		return false
	}

	return HasConfigTx(block.Data)
}

func HasConfigTx(blockdata *cb.BlockData) bool {
	if blockdata.Data == nil {
		return false
	}

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Read the wrapped cause: if it references the key file/HSM, fix keystore contents or PKCS#11/BCCSP configuration in core.yaml.
2. Verify the private key matches the signing certificate (re-enroll or re-export identity if rotated).
3. Check file permissions on the MSP keystore directory for the process user.
4. Prefer the non-panicking path (call signer.Sign directly) so signature failures can be retried/logged instead of crashing the process.

// probe the signer before the panicking API
if _, err := signer.Sign([]byte("probe")); err != nil {
    return fmt.Errorf("signer unhealthy: %w", err)
}
sigma := protoutil.SignOrPanic(signer, msg)

func safeSign(signer identity.Signer, msg []byte) (sig []byte, err error) {
    defer func() {
        if r := recover(); r != nil {
            err = fmt.Errorf("signature generation failed: %v", r)
        }
    }()
    sig = protoutil.SignOrPanic(signer, msg)
    return
}

When it happens

Trigger: signer.Sign returns an error because the underlying private key is missing/corrupt, the keystore cannot be read, the key algorithm is unsupported, or the identity's signer was constructed from invalid material.

Common situations: MSP keystore file permissions or missing key file in production; hardware/HSM (PKCS#11) unreachable; key mismatch between signcerts and keystore after certificate rotation; BCCSP/PKCS11 misconfiguration in core.yaml.

Related errors

• invalid signer. cannot be nil
• failed generating a new SignatureHeader: %s
• error in block index: %s
• Could not retrieve header of the last block form file: %s
• failed to restore working directory: %s

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/bb39a386028f1718. Report an issue: GitHub.