SubjectKeyIdentifier
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Utilities;
using System;
namespace Org.BouncyCastle.Asn1.X509
{
public class SubjectKeyIdentifier : Asn1Encodable
{
private readonly byte[] keyIdentifier;
public static SubjectKeyIdentifier GetInstance(Asn1TaggedObject obj, bool explicitly)
{
return GetInstance(Asn1OctetString.GetInstance(obj, explicitly));
}
public static SubjectKeyIdentifier GetInstance(object obj)
{
if (obj is SubjectKeyIdentifier)
return (SubjectKeyIdentifier)obj;
if (obj is SubjectPublicKeyInfo)
return new SubjectKeyIdentifier((SubjectPublicKeyInfo)obj);
if (obj is X509Extension)
return GetInstance(X509Extension.ConvertValueToObject((X509Extension)obj));
if (obj == null)
return null;
return new SubjectKeyIdentifier(Asn1OctetString.GetInstance(obj));
}
public static SubjectKeyIdentifier FromExtensions(X509Extensions extensions)
{
return GetInstance(X509Extensions.GetExtensionParsedValue(extensions, X509Extensions.SubjectKeyIdentifier));
}
public SubjectKeyIdentifier(byte[] keyID)
{
if (keyID == null)
throw new ArgumentNullException("keyID");
keyIdentifier = Arrays.Clone(keyID);
}
public SubjectKeyIdentifier(Asn1OctetString keyID)
: this(keyID.GetOctets())
{
}
public SubjectKeyIdentifier(SubjectPublicKeyInfo spki)
{
keyIdentifier = GetDigest(spki);
}
public byte[] GetKeyIdentifier()
{
return Arrays.Clone(keyIdentifier);
}
public override Asn1Object ToAsn1Object()
{
return new DerOctetString(GetKeyIdentifier());
}
public static SubjectKeyIdentifier CreateSha1KeyIdentifier(SubjectPublicKeyInfo keyInfo)
{
return new SubjectKeyIdentifier(keyInfo);
}
public static SubjectKeyIdentifier CreateTruncatedSha1KeyIdentifier(SubjectPublicKeyInfo keyInfo)
{
byte[] digest = GetDigest(keyInfo);
byte[] array = new byte[8];
Array.Copy(digest, digest.Length - 8, array, 0, array.Length);
array[0] &= 15;
array[0] |= 64;
return new SubjectKeyIdentifier(array);
}
private static byte[] GetDigest(SubjectPublicKeyInfo spki)
{
Sha1Digest sha1Digest = new Sha1Digest();
byte[] array = new byte[((IDigest)sha1Digest).GetDigestSize()];
byte[] bytes = spki.PublicKey.GetBytes();
((IDigest)sha1Digest).BlockUpdate(bytes, 0, bytes.Length);
((IDigest)sha1Digest).DoFinal(array, 0);
return array;
}
}
}