/// <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));
}
private static TlvTagBuilder GetBuilder(KsiSignature signature)
{
TlvTagBuilder builder = new TlvTagBuilder(Constants.CalendarHashChain.TagType, false, false);
foreach (ITlvTag child in signature.CalendarHashChain)
{
CalendarHashChain.Link link = child as CalendarHashChain.Link;
if (link != null && link.Type == (uint)LinkDirection.Right)
{
// add a left link, this does not make the verification to fail.
builder.AddChildTag(new RawTag((uint)LinkDirection.Left, false, false, Base16.Decode("01580192B0D06E48884432DFFC26A67C6C685BEAF0252B9DD2A0B4B05D1724C5F2")));
}
builder.AddChildTag(child);
}
return(builder);
}
/// <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);
}
