DigestAlgorithmsBuilder
class DigestAlgorithmsBuilder
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Operators.Utilities;
using Org.BouncyCastle.X509;
using System;
using System.Collections.Generic;
namespace Org.BouncyCastle.Cms
{
internal class DigestAlgorithmsBuilder
{
private struct UniqueAlgID : IEquatable<UniqueAlgID>
{
private readonly AlgorithmIdentifier m_algID;
private readonly int m_hashCode;
internal AlgorithmIdentifier AlgID => m_algID;
internal UniqueAlgID(AlgorithmIdentifier algID)
{
if (algID == null)
throw new ArgumentNullException("algID");
m_algID = algID;
m_hashCode = CalculateHashCode(algID);
}
public override bool Equals(object obj)
{
if (obj is UniqueAlgID) {
UniqueAlgID other = (UniqueAlgID)obj;
return Equivalent(other);
}
return false;
}
public override int GetHashCode()
{
return m_hashCode;
}
bool IEquatable<UniqueAlgID>.Equals(UniqueAlgID other)
{
return Equivalent(other);
}
private static int CalculateHashCode(AlgorithmIdentifier algID)
{
if (X509Utilities.HasAbsentParameters(algID))
return algID.Algorithm.GetHashCode();
return algID.GetHashCode();
}
private bool Equivalent(UniqueAlgID other)
{
if (m_hashCode == other.m_hashCode)
return X509Utilities.AreEquivalentAlgorithms(m_algID, other.m_algID);
return false;
}
}
private readonly List<AlgorithmIdentifier> m_ordered = new List<AlgorithmIdentifier>();
private readonly HashSet<UniqueAlgID> m_unique = new HashSet<UniqueAlgID>();
private readonly IDigestAlgorithmFinder m_digestAlgorithmFinder;
internal DigestAlgorithmsBuilder(IDigestAlgorithmFinder digestAlgorithmFinder)
{
m_digestAlgorithmFinder = digestAlgorithmFinder;
}
internal bool Add(AlgorithmIdentifier algID)
{
if (algID == null)
throw new ArgumentNullException("algID");
return ImplAdd(GetCanonical(algID));
}
internal bool AddExisting(AlgorithmIdentifier algID)
{
if (algID == null)
throw new ArgumentNullException("algID");
return ImplAdd(algID);
}
internal void AddExisting(IEnumerable<AlgorithmIdentifier> algIDs)
{
if (algIDs == null)
throw new ArgumentNullException("algIDs");
foreach (AlgorithmIdentifier algID in algIDs) {
AddExisting(algID);
}
}
internal Asn1Set Build(bool useDL)
{
return m_ordered.ToAsn1Set(false, useDL);
}
internal bool Contains(AlgorithmIdentifier algID)
{
return m_unique.Contains(new UniqueAlgID(algID));
}
private bool ImplAdd(AlgorithmIdentifier algID)
{
bool num = m_unique.Add(new UniqueAlgID(algID));
if (num)
m_ordered.Add(algID);
return num;
}
private AlgorithmIdentifier GetCanonical(AlgorithmIdentifier algID)
{
if (!X509Utilities.HasAbsentParameters(algID))
return algID;
return m_digestAlgorithmFinder.Find(algID.Algorithm);
}
}
}