private static string ExtractAlgorithm(string jwt)
{
var algorithm = string.Empty;
if (!string.IsNullOrEmpty(jwt))
{
try
{
algorithm = JoseHelper.ExtractJosePartField(jwt, 0, "alg").ToString();
}
catch (Exception)
{
// Ignore on purpose
}
}
return(algorithm);
}
private static string[] ExtractCertificates(string jwt)
{
string[] certificates = new string[0];
if (!string.IsNullOrEmpty(jwt))
{
try
{
var parsedBody = JoseHelper.ExtractJosePart(jwt, 1);
var parsedCertificates = parsedBody["maa-policyCertificates"]["keys"].ToArray();
certificates = parsedCertificates.Select(c => c.ToString()).ToArray();
}
catch (Exception)
{
// Ignore on purpose
}
}
return(certificates);
}
private static (string algorithm, string jku) ExtractHeaders(string jwt)
{
var algorithm = "";
var jku = "";
if (!string.IsNullOrEmpty(jwt))
{
try
{
var parsedHeader = JoseHelper.ExtractJosePart(jwt, 0);
algorithm = parsedHeader["alg"].ToString();
jku = parsedHeader["jku"].ToString();
}
catch (Exception)
{
// Ignore on purpose
}
}
return(algorithm, jku);
}
private static string ExtractPolicyText(string jwt)
{
string parsedPolicy = string.Empty;
if (!string.IsNullOrEmpty(jwt))
{
try
{
parsedPolicy = JoseHelper.ExtractJosePartField(jwt, 1, "AttestationPolicy").ToString();
// Policy is optionally double base64 URL encoded. We will attempt
// to base64 URL decode a second time -- if this throws an exception,
// that's OK -- we should just use value as it stands now.
var doubleDecodedPolicy = Base64Url.DecodeString(parsedPolicy);
parsedPolicy = doubleDecodedPolicy;
}
catch (Exception)
{
// Ignore on purpose
}
}
return(parsedPolicy);
}