public static bool VerifySignature(this ILicenseBlob b, IEnumerable <RSADecryptPublic> trustedKeys, StringBuilder log)
{
return(trustedKeys.Any(p =>
{
var signature = b.Signature();
var hash = new SHA512Managed().ComputeHash(b.Data());
var decrypted_bytes = p.DecryptPublic(signature);
var valid = hash.SequenceEqual(decrypted_bytes);
if (log != null)
{
log.AppendLine("Using public exponent " + p.Exponent.ToString() + " and modulus " + p.Modulus.ToString());
log.AppendLine("Encrypted bytes: " + BitConverter.ToString(signature).ToLower().Replace("-", ""));
log.AppendLine("Decrypted sha512: " + BitConverter.ToString(decrypted_bytes).ToLower().Replace("-", ""));
log.AppendLine("Expected sha512: " + BitConverter.ToString(hash).ToLower().Replace("-", ""));
log.AppendLine(valid ? "Success!" : "Not a match.");
}
return valid;
}));
}