/// <summary>
/// In the file was changed or the timestamp signature is altered, an exception will be thrown.
/// </summary>
/// <param name="originalFile"></param>
/// <param name="timestampToken"></param>
/// <returns></returns>
public static bool IsTsaReponseFileValid(byte[] originalFile, byte[] timestampToken)
{
bool flag;
try
{
TimestampInfo infoFromTsaResponse = TimestampInfo.GetInfoFromTsaResponse(timestampToken);
if (infoFromTsaResponse == null || infoFromTsaResponse.HashAlgorithm == null)
{
throw new Exception("The timestamp token is not a valid timestamp response.");
}
if (infoFromTsaResponse.IsTimestampAltered)
{
throw new Exception("The timestamp response is altered.");
}
byte[] numArray = TimestampInfo.ComputeHash(originalFile, infoFromTsaResponse.HashAlgorithm);
if (!TimestampInfo.CompareHashes(infoFromTsaResponse.OriginalDataHash, numArray))
{
throw new Exception("The hash that appear on the timestamp response is not identical with the calculated file hash.");
}
flag = true;
}
catch
{
throw;
}
return(flag);
}
public static TimestampInfo GetInfoFromTsaResponse(byte[] timestampToken)
{
TimestampInfo timestampInfo;
try
{
TimeStampResponse timeStampResponse = new TimeStampResponse(timestampToken);
timestampInfo = new TimestampInfo(timeStampResponse.TimeStampToken.GetEncoded());
}
catch
{
try
{
timestampInfo = new TimestampInfo(timestampToken);
}
catch
{
timestampInfo = null;
}
}
return(timestampInfo);
}