Initial Commit

iTechSharp/srcbc/asn1/isismtt/ocsp/CertHash.cs

@@ -0,0 +1,121 @@
+using System;
+
+using Org.BouncyCastle.Asn1.X509;
+
+namespace Org.BouncyCastle.Asn1.IsisMtt.Ocsp
+{
+	/**
+	* ISIS-MTT PROFILE: The responder may include this extension in a response to
+	* send the hash of the requested certificate to the responder. This hash is
+	* cryptographically bound to the certificate and serves as evidence that the
+	* certificate is known to the responder (i.e. it has been issued and is present
+	* in the directory). Hence, this extension is a means to provide a positive
+	* statement of availability as described in T8.[8]. As explained in T13.[1],
+	* clients may rely on this information to be able to validate signatures after
+	* the expiry of the corresponding certificate. Hence, clients MUST support this
+	* extension. If a positive statement of availability is to be delivered, this
+	* extension syntax and OID MUST be used.
+	* <p/>
+	* <p/>
+	* <pre>
+	*     CertHash ::= SEQUENCE {
+	*       hashAlgorithm AlgorithmIdentifier,
+	*       certificateHash OCTET STRING
+	*     }
+	* </pre>
+	*/
+	public class CertHash
+		: Asn1Encodable
+	{
+		private readonly AlgorithmIdentifier	hashAlgorithm;
+		private readonly byte[]					certificateHash;
+
+		public static CertHash GetInstance(
+			object obj)
+		{
+			if (obj == null || obj is CertHash)
+			{
+				return (CertHash) obj;
+			}
+
+			if (obj is Asn1Sequence)
+			{
+				return new CertHash((Asn1Sequence) obj);
+			}
+
+			throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
+		}
+
+		/**
+		* Constructor from Asn1Sequence.
+		* <p/>
+		* The sequence is of type CertHash:
+		* <p/>
+		* <pre>
+		*     CertHash ::= SEQUENCE {
+		*       hashAlgorithm AlgorithmIdentifier,
+		*       certificateHash OCTET STRING
+		*     }
+		* </pre>
+		*
+		* @param seq The ASN.1 sequence.
+		*/
+		private CertHash(
+			Asn1Sequence seq)
+		{
+			if (seq.Count != 2)
+				throw new ArgumentException("Bad sequence size: " + seq.Count);
+
+			this.hashAlgorithm = AlgorithmIdentifier.GetInstance(seq[0]);
+			this.certificateHash = DerOctetString.GetInstance(seq[1]).GetOctets();
+		}
+
+		/**
+		* Constructor from a given details.
+		*
+		* @param hashAlgorithm   The hash algorithm identifier.
+		* @param certificateHash The hash of the whole DER encoding of the certificate.
+		*/
+		public CertHash(
+			AlgorithmIdentifier	hashAlgorithm,
+			byte[]				certificateHash)
+		{
+			if (hashAlgorithm == null)
+				throw new ArgumentNullException("hashAlgorithm");
+			if (certificateHash == null)
+				throw new ArgumentNullException("certificateHash");
+
+			this.hashAlgorithm = hashAlgorithm;
+			this.certificateHash = (byte[]) certificateHash.Clone();
+		}
+
+		public AlgorithmIdentifier HashAlgorithm
+		{
+			get { return hashAlgorithm; }
+		}
+
+		public byte[] CertificateHash
+		{
+			get { return (byte[]) certificateHash.Clone(); }
+		}
+
+		/**
+		* Produce an object suitable for an Asn1OutputStream.
+		* <p/>
+		* Returns:
+		* <p/>
+		* <pre>
+		*     CertHash ::= SEQUENCE {
+		*       hashAlgorithm AlgorithmIdentifier,
+		*       certificateHash OCTET STRING
+		*     }
+		* </pre>
+		*
+		* @return an Asn1Object
+		*/
+		public override Asn1Object ToAsn1Object()
+		{
+			return new DerSequence(hashAlgorithm, new DerOctetString(certificateHash));
+		}
+	}
+}