1 files changed, 35 insertions, 31 deletions

diff --git a/crypto/src/asn1/pkcs/PBES2Parameters.cs b/crypto/src/asn1/pkcs/PBES2Parameters.cs
index 645bb867c..fc6904eed 100644
--- a/crypto/src/asn1/pkcs/PBES2Parameters.cs
+++ b/crypto/src/asn1/pkcs/PBES2Parameters.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Collections;
 
 namespace Org.BouncyCastle.Asn1.Pkcs
 {
@@ -9,53 +8,58 @@ namespace Org.BouncyCastle.Asn1.Pkcs
         private readonly KeyDerivationFunc func;
         private readonly EncryptionScheme scheme;
 
-		public static PbeS2Parameters GetInstance(
-			object obj)
-		{
-			if (obj == null || obj is PbeS2Parameters)
-				return (PbeS2Parameters) obj;
-
-			if (obj is Asn1Sequence)
-				return new PbeS2Parameters((Asn1Sequence) obj);
+        public static PbeS2Parameters GetInstance(object obj)
+        {
+            if (obj == null)
+                return null;
+            PbeS2Parameters existing = obj as PbeS2Parameters;
+            if (existing != null)
+                return existing;
+            return new PbeS2Parameters(Asn1Sequence.GetInstance(obj));
+        }
 
-			throw new ArgumentException("Unknown object in factory: " + obj.GetType().FullName, "obj");
-		}
+        public PbeS2Parameters(KeyDerivationFunc keyDevFunc, EncryptionScheme encScheme)
+        {
+            this.func = keyDevFunc;
+            this.scheme = encScheme;
+        }
 
-		public PbeS2Parameters(
+        [Obsolete("Use GetInstance() instead")]
+        public PbeS2Parameters(
             Asn1Sequence seq)
         {
-			if (seq.Count != 2)
-				throw new ArgumentException("Wrong number of elements in sequence", "seq");
+            if (seq.Count != 2)
+                throw new ArgumentException("Wrong number of elements in sequence", "seq");
 
-			Asn1Sequence funcSeq = (Asn1Sequence)seq[0].ToAsn1Object();
+            Asn1Sequence funcSeq = (Asn1Sequence)seq[0].ToAsn1Object();
 
-			// TODO Not sure if this special case is really necessary/appropriate
-			if (funcSeq[0].Equals(PkcsObjectIdentifiers.IdPbkdf2))
+            // TODO Not sure if this special case is really necessary/appropriate
+            if (funcSeq[0].Equals(PkcsObjectIdentifiers.IdPbkdf2))
             {
-				func = new KeyDerivationFunc(PkcsObjectIdentifiers.IdPbkdf2,
-					Pbkdf2Params.GetInstance(funcSeq[1]));
-			}
+                func = new KeyDerivationFunc(PkcsObjectIdentifiers.IdPbkdf2,
+                    Pbkdf2Params.GetInstance(funcSeq[1]));
+            }
             else
             {
                 func = new KeyDerivationFunc(funcSeq);
             }
 
-			scheme = EncryptionScheme.GetInstance(seq[1].ToAsn1Object());
+            scheme = EncryptionScheme.GetInstance(seq[1].ToAsn1Object());
         }
 
-		public KeyDerivationFunc KeyDerivationFunc
-		{
-			get { return func; }
-		}
+        public KeyDerivationFunc KeyDerivationFunc
+        {
+            get { return func; }
+        }
 
-		public EncryptionScheme EncryptionScheme
-		{
-			get { return scheme; }
-		}
+        public EncryptionScheme EncryptionScheme
+        {
+            get { return scheme; }
+        }
 
-		public override Asn1Object ToAsn1Object()
+        public override Asn1Object ToAsn1Object()
         {
-			return new DerSequence(func, scheme);
+            return new DerSequence(func, scheme);
         }
     }
 }