Initial Commit

iTechSharp/srcbc/asn1/x509/SubjectKeyIdentifier.cs

@@ -0,0 +1,95 @@
+using System;
+
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.Digests;
+
+namespace Org.BouncyCastle.Asn1.X509
+{
+    /**
+     * The SubjectKeyIdentifier object.
+     * <pre>
+     * SubjectKeyIdentifier::= OCTET STRING
+     * </pre>
+     */
+    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 Asn1OctetString)
+            {
+                return new SubjectKeyIdentifier((Asn1OctetString) obj);
+            }
+
+			if (obj is X509Extension)
+			{
+				return GetInstance(X509Extension.ConvertValueToObject((X509Extension) obj));
+			}
+
+			throw new ArgumentException("Invalid SubjectKeyIdentifier: " + obj.GetType().Name);
+        }
+
+		public SubjectKeyIdentifier(
+            byte[] keyID)
+        {
+			if (keyID == null)
+				throw new ArgumentNullException("keyID");
+
+			this.keyIdentifier = keyID;
+        }
+
+		public SubjectKeyIdentifier(
+            Asn1OctetString keyID)
+        {
+            this.keyIdentifier = keyID.GetOctets();
+        }
+
+		/**
+         *
+         * Calulates the keyIdentifier using a SHA1 hash over the BIT STRING
+         * from SubjectPublicKeyInfo as defined in RFC2459.
+         *
+         **/
+        public SubjectKeyIdentifier(
+            SubjectPublicKeyInfo spki)
+        {
+            IDigest digest = new Sha1Digest();
+            byte[] resBuf = new byte[digest.GetDigestSize()];
+
+			byte[] bytes = spki.PublicKeyData.GetBytes();
+            digest.BlockUpdate(bytes, 0, bytes.Length);
+            digest.DoFinal(resBuf, 0);
+            this.keyIdentifier = resBuf;
+        }
+
+		public byte[] GetKeyIdentifier()
+        {
+            return keyIdentifier;
+        }
+
+		public override Asn1Object ToAsn1Object()
+        {
+            return new DerOctetString(keyIdentifier);
+        }
+    }
+}