/// <see cref="VerificationRule.Verify" />
public override VerificationResult Verify(IVerificationContext context)
{
CalendarHashChain calendarHashChain = GetSignature(context).CalendarHashChain;
// If calendar hash chain is missing, verification successful
if (calendarHashChain == null)
{
return(new VerificationResult(GetRuleName(), VerificationResultCode.Ok));
}
IEnumerator <CalendarHashChain.Link> linksEnumerator = calendarHashChain.GetLeftLinksEnumerator();
CalendarHashChain.Link link = linksEnumerator.MoveNext() ? linksEnumerator.Current : null;
while (link != null)
{
if (link.Value.Algorithm.IsObsolete(calendarHashChain.PublicationTime))
{
Logger.Debug("Calendar hash chain contains obsolete aggregation algorithm at publication time. Algorithm: {0}; Publication time: {1}",
link.Value.Algorithm.Name, calendarHashChain.PublicationTime);
return(new VerificationResult(GetRuleName(), VerificationResultCode.Fail, VerificationError.Int16));
}
link = linksEnumerator.MoveNext() ? linksEnumerator.Current : null;
}
return(new VerificationResult(GetRuleName(), VerificationResultCode.Ok));
}
/// <summary>
/// Get first deprecated hash algorithm from calendar hash chain.
/// </summary>
/// <param name="calendarHashChain"></param>
/// <returns></returns>
public static HashAlgorithm GetDeprecatedHashAlgorithm(CalendarHashChain calendarHashChain)
{
IEnumerator <CalendarHashChain.Link> linksEnumerator = calendarHashChain.GetLeftLinksEnumerator();
CalendarHashChain.Link link = linksEnumerator.MoveNext() ? linksEnumerator.Current : null;
while (link != null)
{
if (link.Value.Algorithm.IsDeprecated(calendarHashChain.PublicationTime))
{
return(link.Value.Algorithm);
}
link = linksEnumerator.MoveNext() ? linksEnumerator.Current : null;
}
return(null);
}