return CertificateInvalidError{c, NotAuthorizedToSign, ""}
	}

	if c.BasicConstraintsValid && c.MaxPathLen >= 0 {
		numIntermediates := len(currentChain) - 1
		if numIntermediates > c.MaxPathLen {
			return CertificateInvalidError{c, TooManyIntermediates, ""}
		}
	}

	if !boringAllowCert(c) {
		// IncompatibleUsage is not quite right here,