1 files changed, 108 insertions, 0 deletions
diff --git a/crypto/src/asn1/nist/NISTNamedCurves.cs b/crypto/src/asn1/nist/NISTNamedCurves.cs
new file mode 100644
index 000000000..0e82dda7a
--- /dev/null
+++ b/crypto/src/asn1/nist/NISTNamedCurves.cs
@@ -0,0 +1,108 @@
+using System;
+using System.Collections;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.Sec;
+using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Collections;
+
+namespace Org.BouncyCastle.Asn1.Nist
+{
+    /**
+    * Utility class for fetching curves using their NIST names as published in FIPS-PUB 186-3
+    */
+    public sealed class NistNamedCurves
+    {
+        private NistNamedCurves()
+        {
+        }
+
+        private static readonly IDictionary objIds = Platform.CreateHashtable();
+        private static readonly IDictionary names = Platform.CreateHashtable();
+
+        private static void DefineCurve(
+            string				name,
+            DerObjectIdentifier	oid)
+        {
+            objIds.Add(name, oid);
+            names.Add(oid, name);
+        }
+
+        static NistNamedCurves()
+        {
+            DefineCurve("B-571", SecObjectIdentifiers.SecT571r1);
+            DefineCurve("B-409", SecObjectIdentifiers.SecT409r1);
+            DefineCurve("B-283", SecObjectIdentifiers.SecT283r1);
+            DefineCurve("B-233", SecObjectIdentifiers.SecT233r1);
+            DefineCurve("B-163", SecObjectIdentifiers.SecT163r2);
+            DefineCurve("K-571", SecObjectIdentifiers.SecT571k1);
+            DefineCurve("K-409", SecObjectIdentifiers.SecT409k1);
+            DefineCurve("K-283", SecObjectIdentifiers.SecT283k1);
+            DefineCurve("K-233", SecObjectIdentifiers.SecT233k1);
+            DefineCurve("K-163", SecObjectIdentifiers.SecT163k1);
+            DefineCurve("P-521", SecObjectIdentifiers.SecP521r1);
+            DefineCurve("P-384", SecObjectIdentifiers.SecP384r1);
+            DefineCurve("P-256", SecObjectIdentifiers.SecP256r1);
+            DefineCurve("P-224", SecObjectIdentifiers.SecP224r1);
+            DefineCurve("P-192", SecObjectIdentifiers.SecP192r1);
+        }
+
+        public static X9ECParameters GetByName(
+            string name)
+        {
+            DerObjectIdentifier oid = (DerObjectIdentifier) objIds[
+                Platform.ToUpperInvariant(name)];
+
+            if (oid != null)
+            {
+                return GetByOid(oid);
+            }
+
+            return null;
+        }
+
+        /**
+        * return the X9ECParameters object for the named curve represented by
+        * the passed in object identifier. Null if the curve isn't present.
+        *
+        * @param oid an object identifier representing a named curve, if present.
+        */
+        public static X9ECParameters GetByOid(
+            DerObjectIdentifier oid)
+        {
+            return SecNamedCurves.GetByOid(oid);
+        }
+
+        /**
+        * return the object identifier signified by the passed in name. Null
+        * if there is no object identifier associated with name.
+        *
+        * @return the object identifier associated with name, if present.
+        */
+        public static DerObjectIdentifier GetOid(
+            string name)
+        {
+            return (DerObjectIdentifier) objIds[
+                Platform.ToUpperInvariant(name)];
+        }
+
+        /**
+        * return the named curve name represented by the given object identifier.
+        */
+        public static string GetName(
+            DerObjectIdentifier  oid)
+        {
+            return (string) names[oid];
+        }
+
+        /**
+        * returns an enumeration containing the name strings for curves
+        * contained in this structure.
+        */
+        public static IEnumerable Names
+        {
+            get { return new EnumerableProxy(objIds.Keys); }
+        }
+    }
+}