Initial Commit

iTechSharp/srcbc/asn1/pkcs/RSASSAPSSparams.cs

@@ -0,0 +1,165 @@
+using System;
+
+using Org.BouncyCastle.Asn1.Oiw;
+using Org.BouncyCastle.Asn1.X509;
+
+namespace Org.BouncyCastle.Asn1.Pkcs
+{
+	public class RsassaPssParameters
+		: Asn1Encodable
+	{
+		private AlgorithmIdentifier hashAlgorithm;
+		private AlgorithmIdentifier maskGenAlgorithm;
+		private DerInteger saltLength;
+		private DerInteger trailerField;
+
+		public readonly static AlgorithmIdentifier DefaultHashAlgorithm = new AlgorithmIdentifier(OiwObjectIdentifiers.IdSha1, DerNull.Instance);
+		public readonly static AlgorithmIdentifier DefaultMaskGenFunction = new AlgorithmIdentifier(PkcsObjectIdentifiers.IdMgf1, DefaultHashAlgorithm);
+		public readonly static DerInteger DefaultSaltLength = new DerInteger(20);
+		public readonly static DerInteger DefaultTrailerField = new DerInteger(1);
+
+		public static RsassaPssParameters GetInstance(
+			object obj)
+		{
+			if (obj == null || obj is RsassaPssParameters)
+			{
+				return (RsassaPssParameters)obj;
+			}
+
+			if (obj is Asn1Sequence)
+			{
+				return new RsassaPssParameters((Asn1Sequence)obj);
+			}
+
+			throw new ArgumentException("Unknown object in factory: " + obj.GetType().FullName, "obj");
+		}
+
+		/**
+		 * The default version
+		 */
+		public RsassaPssParameters()
+		{
+			hashAlgorithm = DefaultHashAlgorithm;
+			maskGenAlgorithm = DefaultMaskGenFunction;
+			saltLength = DefaultSaltLength;
+			trailerField = DefaultTrailerField;
+		}
+
+		public RsassaPssParameters(
+			AlgorithmIdentifier hashAlgorithm,
+			AlgorithmIdentifier maskGenAlgorithm,
+			DerInteger saltLength,
+			DerInteger trailerField)
+		{
+			this.hashAlgorithm = hashAlgorithm;
+			this.maskGenAlgorithm = maskGenAlgorithm;
+			this.saltLength = saltLength;
+			this.trailerField = trailerField;
+		}
+
+		public RsassaPssParameters(
+			Asn1Sequence seq)
+		{
+			hashAlgorithm = DefaultHashAlgorithm;
+			maskGenAlgorithm = DefaultMaskGenFunction;
+			saltLength = DefaultSaltLength;
+			trailerField = DefaultTrailerField;
+
+			for (int i = 0; i != seq.Count; i++)
+			{
+				Asn1TaggedObject o = (Asn1TaggedObject)seq[i];
+
+				switch (o.TagNo)
+				{
+					case 0:
+						hashAlgorithm = AlgorithmIdentifier.GetInstance(o, true);
+						break;
+					case 1:
+						maskGenAlgorithm = AlgorithmIdentifier.GetInstance(o, true);
+						break;
+					case 2:
+						saltLength = DerInteger.GetInstance(o, true);
+						break;
+					case 3:
+						trailerField = DerInteger.GetInstance(o, true);
+						break;
+					default:
+						throw new ArgumentException("unknown tag");
+				}
+			}
+		}
+
+		public AlgorithmIdentifier HashAlgorithm
+		{
+			get { return hashAlgorithm; }
+		}
+
+		public AlgorithmIdentifier MaskGenAlgorithm
+		{
+			get { return maskGenAlgorithm; }
+		}
+
+		public DerInteger SaltLength
+		{
+			get { return saltLength; }
+		}
+
+		public DerInteger TrailerField
+		{
+			get { return trailerField; }
+		}
+
+		/**
+		 * <pre>
+		 * RSASSA-PSS-params ::= SEQUENCE {
+		 *   hashAlgorithm      [0] OAEP-PSSDigestAlgorithms  DEFAULT sha1,
+		 *    maskGenAlgorithm   [1] PKCS1MGFAlgorithms  DEFAULT mgf1SHA1,
+		 *    saltLength         [2] INTEGER  DEFAULT 20,
+		 *    trailerField       [3] TrailerField  DEFAULT trailerFieldBC
+		 *  }
+		 *
+		 * OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
+		 *    { OID id-sha1 PARAMETERS NULL   }|
+		 *    { OID id-sha256 PARAMETERS NULL }|
+		 *    { OID id-sha384 PARAMETERS NULL }|
+		 *    { OID id-sha512 PARAMETERS NULL },
+		 *    ...  -- Allows for future expansion --
+		 * }
+		 *
+		 * PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {
+		 *   { OID id-mgf1 PARAMETERS OAEP-PSSDigestAlgorithms },
+		 *    ...  -- Allows for future expansion --
+		 * }
+		 *
+		 * TrailerField ::= INTEGER { trailerFieldBC(1) }
+		 * </pre>
+		 * @return the asn1 primitive representing the parameters.
+		 */
+		public override Asn1Object ToAsn1Object()
+		{
+			Asn1EncodableVector v = new Asn1EncodableVector();
+
+			if (!hashAlgorithm.Equals(DefaultHashAlgorithm))
+			{
+				v.Add(new DerTaggedObject(true, 0, hashAlgorithm));
+			}
+
+			if (!maskGenAlgorithm.Equals(DefaultMaskGenFunction))
+			{
+				v.Add(new DerTaggedObject(true, 1, maskGenAlgorithm));
+			}
+
+			if (!saltLength.Equals(DefaultSaltLength))
+			{
+				v.Add(new DerTaggedObject(true, 2, saltLength));
+			}
+
+			if (!trailerField.Equals(DefaultTrailerField))
+			{
+				v.Add(new DerTaggedObject(true, 3, trailerField));
+			}
+
+			return new DerSequence(v);
+		}
+	}
+}