using System; namespace Org.BouncyCastle.Asn1.X509 { public class AlgorithmIdentifier : Asn1Encodable { private readonly DerObjectIdentifier m_algorithm; private readonly Asn1Encodable m_parameters; public virtual DerObjectIdentifier Algorithm => m_algorithm; public virtual Asn1Encodable Parameters => m_parameters; public static AlgorithmIdentifier GetInstance(object obj) { if (obj == null) return null; AlgorithmIdentifier algorithmIdentifier = obj as AlgorithmIdentifier; if (algorithmIdentifier != null) return algorithmIdentifier; return new AlgorithmIdentifier(Asn1Sequence.GetInstance(obj)); } public static AlgorithmIdentifier GetInstance(Asn1TaggedObject obj, bool explicitly) { return new AlgorithmIdentifier(Asn1Sequence.GetInstance(obj, explicitly)); } public static AlgorithmIdentifier GetOptional(Asn1Encodable element) { if (element == null) throw new ArgumentNullException("element"); AlgorithmIdentifier algorithmIdentifier = element as AlgorithmIdentifier; if (algorithmIdentifier != null) return algorithmIdentifier; Asn1Sequence optional = Asn1Sequence.GetOptional(element); if (optional != null) return new AlgorithmIdentifier(optional); return null; } public static AlgorithmIdentifier GetTagged(Asn1TaggedObject taggedObject, bool declaredExplicit) { return new AlgorithmIdentifier(Asn1Sequence.GetTagged(taggedObject, declaredExplicit)); } internal AlgorithmIdentifier(Asn1Sequence seq) { int count = seq.Count; if (count < 1 || count > 2) throw new ArgumentException("Bad sequence size: " + count.ToString(), "seq"); m_algorithm = DerObjectIdentifier.GetInstance(seq[0]); m_parameters = ((count < 2) ? null : seq[1]); } public AlgorithmIdentifier(DerObjectIdentifier algorithm) : this(algorithm, null) { } public AlgorithmIdentifier(DerObjectIdentifier algorithm, Asn1Encodable parameters) { if (algorithm == null) throw new ArgumentNullException("algorithm"); m_algorithm = algorithm; m_parameters = parameters; } public override Asn1Object ToAsn1Object() { if (m_parameters != null) return new DerSequence(m_algorithm, m_parameters); return new DerSequence(m_algorithm); } } }