ASN.1: Port of bc-java TYPE instances

- we use Meta.Instance here due to syntax restrictions
- also reworked some ASN.1 string types

1 files changed, 63 insertions, 33 deletions

diff --git a/crypto/src/asn1/DerGeneralString.cs b/crypto/src/asn1/DerGeneralString.cs
index f2a47c370..e6637732a 100644
--- a/crypto/src/asn1/DerGeneralString.cs
+++ b/crypto/src/asn1/DerGeneralString.cs
@@ -1,5 +1,5 @@
 using System;
-using System.Text;
+using System.IO;
 
 using Org.BouncyCastle.Utilities;
 
@@ -8,78 +8,108 @@ namespace Org.BouncyCastle.Asn1
     public class DerGeneralString
         : DerStringBase
     {
-        private readonly string str;
+        internal class Meta : Asn1UniversalType 
+        {
+            internal static readonly Asn1UniversalType Instance = new Meta();
+
+            private Meta() : base(typeof(DerGeneralString), Asn1Tags.GeneralString) {}
+
+            internal override Asn1Object FromImplicitPrimitive(DerOctetString octetString)
+            {
+                return CreatePrimitive(octetString.GetOctets());
+            }
+        }
 
-        public static DerGeneralString GetInstance(
-            object obj)
+        public static DerGeneralString GetInstance(object obj)
         {
             if (obj == null || obj is DerGeneralString)
             {
                 return (DerGeneralString) obj;
             }
+            else if (obj is IAsn1Convertible)
+            {
+                Asn1Object asn1Object = ((IAsn1Convertible)obj).ToAsn1Object();
+                if (asn1Object is DerGeneralString)
+                    return (DerGeneralString)asn1Object;
+            }
+            else if (obj is byte[])
+            {
+                try
+                {
+                    return (DerGeneralString)Meta.Instance.FromByteArray((byte[])obj);
+                }
+                catch (IOException e)
+                {
+                    throw new ArgumentException("failed to construct general string from byte[]: " + e.Message);
+                }
+            }
 
-			throw new ArgumentException("illegal object in GetInstance: "
-                    + Platform.GetTypeName(obj));
+            throw new ArgumentException("illegal object in GetInstance: " + Platform.GetTypeName(obj));
         }
 
-        public static DerGeneralString GetInstance(
-            Asn1TaggedObject	obj,
-            bool				isExplicit)
+        public static DerGeneralString GetInstance(Asn1TaggedObject taggedObject, bool declaredExplicit)
         {
-			Asn1Object o = obj.GetObject();
+            return (DerGeneralString)Meta.Instance.GetContextInstance(taggedObject, declaredExplicit);
+        }
 
-			if (isExplicit || o is DerGeneralString)
-			{
-				return GetInstance(o);
-			}
+        private readonly byte[] m_contents;
 
-			return new DerGeneralString(((Asn1OctetString)o).GetOctets());
+		public DerGeneralString(string str)
+        {
+			if (str == null)
+				throw new ArgumentNullException("str");
+
+			m_contents = Strings.ToAsciiByteArray(str);
         }
 
-        public DerGeneralString(
-			byte[] str)
-			: this(Strings.FromAsciiByteArray(str))
+        public DerGeneralString(byte[] contents)
+            : this(contents, true)
         {
         }
 
-		public DerGeneralString(
-			string str)
+        internal DerGeneralString(byte[] contents, bool clone)
         {
-			if (str == null)
-				throw new ArgumentNullException("str");
+            if (null == contents)
+                throw new ArgumentNullException("contents");
 
-			this.str = str;
+            m_contents = clone ? Arrays.Clone(contents) : contents;
         }
 
         public override string GetString()
         {
-            return str;
+            return Strings.FromAsciiByteArray(m_contents);
         }
 
 		public byte[] GetOctets()
         {
-            return Strings.ToAsciiByteArray(str);
+            return Arrays.Clone(m_contents);
         }
 
         internal override IAsn1Encoding GetEncoding(int encoding)
         {
-            return new PrimitiveEncoding(Asn1Tags.Universal, Asn1Tags.GeneralString, GetOctets());
+            return new PrimitiveEncoding(Asn1Tags.Universal, Asn1Tags.GeneralString, m_contents);
         }
 
         internal override IAsn1Encoding GetEncodingImplicit(int encoding, int tagClass, int tagNo)
         {
-            return new PrimitiveEncoding(tagClass, tagNo, GetOctets());
+            return new PrimitiveEncoding(tagClass, tagNo, m_contents);
         }
 
-        protected override bool Asn1Equals(
-			Asn1Object asn1Object)
+        protected override bool Asn1Equals(Asn1Object asn1Object)
         {
-			DerGeneralString other = asn1Object as DerGeneralString;
+            DerGeneralString that = asn1Object as DerGeneralString;
+            return null != that
+                && Arrays.AreEqual(this.m_contents, that.m_contents);
+        }
 
-			if (other == null)
-				return false;
+        protected override int Asn1GetHashCode()
+        {
+            return Arrays.GetHashCode(m_contents);
+        }
 
-			return this.str.Equals(other.str);
+        internal static DerGeneralString CreatePrimitive(byte[] contents)
+        {
+            return new DerGeneralString(contents, false);
         }
     }
 }