1 files changed, 102 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..3b4c59df2
--- /dev/null
+++ b/Crypto/src/asn1/nist/NISTNamedCurves.cs
@@ -0,0 +1,102 @@
+using System;
+using System.Collections;
+using System.Globalization;
+
+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 186-2
+ */
+ 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("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[name.ToUpperInvariant()];
+
+ 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[name.ToUpperInvariant()];
+ }
+
+ /**
+ * 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); }
+ }
+ }
+}
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