protected DigitallySigned parseSignature(InputStream input) throws IOException { DigitallySigned signature = DigitallySigned.parse(context, input); SignatureAndHashAlgorithm signatureAlgorithm = signature.getAlgorithm(); if (signatureAlgorithm != null) { TlsUtils.verifySupportedSignatureAlgorithm(supportedSignatureAlgorithms, signatureAlgorithm); } return signature; }