PrivateKeyInfoAsn.cs

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using System.Collections.Generic;
using System.Formats.Asn1;
 
namespace System.Security.Cryptography.Asn1;
 
internal struct PrivateKeyInfoAsn
{
    internal int Version;
 
    internal System.Security.Cryptography.Asn1.AlgorithmIdentifierAsn PrivateKeyAlgorithm;
 
    internal ReadOnlyMemory<byte> PrivateKey;
 
    internal System.Security.Cryptography.Asn1.AttributeAsn[] Attributes;
 
    internal static System.Security.Cryptography.Asn1.PrivateKeyInfoAsn Decode(ReadOnlyMemory<byte> encoded, AsnEncodingRules ruleSet)
    {
        return Decode(Asn1Tag.Sequence, encoded, ruleSet);
    }
 
    internal static System.Security.Cryptography.Asn1.PrivateKeyInfoAsn Decode(Asn1Tag expectedTag, ReadOnlyMemory<byte> encoded, AsnEncodingRules ruleSet)
    {
        try
        {
            System.Formats.Asn1.AsnValueReader reader = new System.Formats.Asn1.AsnValueReader(encoded.Span, ruleSet);
            DecodeCore(ref reader, expectedTag, encoded, out var decoded);
            reader.ThrowIfNotEmpty();
            return decoded;
        }
        catch (AsnContentException inner)
        {
            throw new CryptographicException(System.SR.Cryptography_Der_Invalid_Encoding, inner);
        }
    }
 
    private static void DecodeCore(ref System.Formats.Asn1.AsnValueReader reader, Asn1Tag expectedTag, ReadOnlyMemory<byte> rebind, out System.Security.Cryptography.Asn1.PrivateKeyInfoAsn decoded)
    {
        decoded = default(System.Security.Cryptography.Asn1.PrivateKeyInfoAsn);
        System.Formats.Asn1.AsnValueReader reader2 = reader.ReadSequence(expectedTag);
        ReadOnlySpan<byte> span = rebind.Span;
        if (!reader2.TryReadInt32(out decoded.Version))
        {
            reader2.ThrowIfNotEmpty();
        }
        System.Security.Cryptography.Asn1.AlgorithmIdentifierAsn.Decode(ref reader2, rebind, out decoded.PrivateKeyAlgorithm);
        if (reader2.TryReadPrimitiveOctetString(out var value))
        {
            decoded.PrivateKey = (span.Overlaps(value, out var elementOffset) ? rebind.Slice(elementOffset, value.Length) : ((ReadOnlyMemory<byte>)value.ToArray()));
        }
        else
        {
            decoded.PrivateKey = reader2.ReadOctetString();
        }
        if (reader2.HasData && reader2.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 0)))
        {
            System.Formats.Asn1.AsnValueReader reader3 = reader2.ReadSetOf(new Asn1Tag(TagClass.ContextSpecific, 0));
            List<System.Security.Cryptography.Asn1.AttributeAsn> list = new List<System.Security.Cryptography.Asn1.AttributeAsn>();
            while (reader3.HasData)
            {
                System.Security.Cryptography.Asn1.AttributeAsn.Decode(ref reader3, rebind, out var decoded2);
                list.Add(decoded2);
            }
            decoded.Attributes = list.ToArray();
        }
        reader2.ThrowIfNotEmpty();
    }
}