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      1 package org.bouncycastle.asn1.nist;
      2 
      3 import org.bouncycastle.asn1.DERObjectIdentifier;
      4 import org.bouncycastle.asn1.sec.SECNamedCurves;
      5 import org.bouncycastle.asn1.sec.SECObjectIdentifiers;
      6 import org.bouncycastle.asn1.x9.X9ECParameters;
      7 import org.bouncycastle.util.Strings;
      8 
      9 import java.util.Enumeration;
     10 import java.util.Hashtable;
     11 
     12 /**
     13  * Utility class for fetching curves using their NIST names as published in FIPS-PUB 186-2
     14  */
     15 public class NISTNamedCurves
     16 {
     17     static final Hashtable objIds = new Hashtable();
     18     static final Hashtable names = new Hashtable();
     19 
     20     static void defineCurve(String name, DERObjectIdentifier oid)
     21     {
     22         objIds.put(name, oid);
     23         names.put(oid, name);
     24     }
     25 
     26     static
     27     {
     28         // TODO Missing the "K-" curves
     29 
     30         defineCurve("B-571", SECObjectIdentifiers.sect571r1);
     31         defineCurve("B-409", SECObjectIdentifiers.sect409r1);
     32         defineCurve("B-283", SECObjectIdentifiers.sect283r1);
     33         defineCurve("B-233", SECObjectIdentifiers.sect233r1);
     34         defineCurve("B-163", SECObjectIdentifiers.sect163r2);
     35         defineCurve("P-521", SECObjectIdentifiers.secp521r1);
     36         defineCurve("P-384", SECObjectIdentifiers.secp384r1);
     37         defineCurve("P-256", SECObjectIdentifiers.secp256r1);
     38         defineCurve("P-224", SECObjectIdentifiers.secp224r1);
     39         defineCurve("P-192", SECObjectIdentifiers.secp192r1);
     40     }
     41 
     42     public static X9ECParameters getByName(
     43         String  name)
     44     {
     45         DERObjectIdentifier oid = (DERObjectIdentifier)objIds.get(Strings.toUpperCase(name));
     46 
     47         if (oid != null)
     48         {
     49             return getByOID(oid);
     50         }
     51 
     52         return null;
     53     }
     54 
     55     /**
     56      * return the X9ECParameters object for the named curve represented by
     57      * the passed in object identifier. Null if the curve isn't present.
     58      *
     59      * @param oid an object identifier representing a named curve, if present.
     60      */
     61     public static X9ECParameters getByOID(
     62         DERObjectIdentifier  oid)
     63     {
     64         return SECNamedCurves.getByOID(oid);
     65     }
     66 
     67     /**
     68      * return the object identifier signified by the passed in name. Null
     69      * if there is no object identifier associated with name.
     70      *
     71      * @return the object identifier associated with name, if present.
     72      */
     73     public static DERObjectIdentifier getOID(
     74         String  name)
     75     {
     76         return (DERObjectIdentifier)objIds.get(Strings.toUpperCase(name));
     77     }
     78 
     79     /**
     80      * return the named curve name represented by the given object identifier.
     81      */
     82     public static String getName(
     83         DERObjectIdentifier  oid)
     84     {
     85         return (String)names.get(oid);
     86     }
     87 
     88     /**
     89      * returns an enumeration containing the name strings for curves
     90      * contained in this structure.
     91      */
     92     public static Enumeration getNames()
     93     {
     94         return objIds.keys();
     95     }
     96 }
     97