1 package org.bouncycastle.jcajce.provider.asymmetric.util; 2 3 import java.math.BigInteger; 4 import java.security.spec.ECField; 5 import java.security.spec.ECFieldF2m; 6 import java.security.spec.ECFieldFp; 7 import java.security.spec.ECParameterSpec; 8 import java.security.spec.ECPoint; 9 import java.security.spec.EllipticCurve; 10 11 import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec; 12 import org.bouncycastle.jce.spec.ECNamedCurveSpec; 13 import org.bouncycastle.math.ec.ECCurve; 14 15 public class EC5Util 16 { convertCurve( ECCurve curve, byte[] seed)17 public static EllipticCurve convertCurve( 18 ECCurve curve, 19 byte[] seed) 20 { 21 // TODO: the Sun EC implementation doesn't currently handle the seed properly 22 // so at the moment it's set to null. Should probably look at making this configurable 23 if (curve instanceof ECCurve.Fp) 24 { 25 return new EllipticCurve(new ECFieldFp(((ECCurve.Fp)curve).getQ()), curve.getA().toBigInteger(), curve.getB().toBigInteger(), null); 26 } 27 else 28 { 29 ECCurve.F2m curveF2m = (ECCurve.F2m)curve; 30 int ks[]; 31 32 if (curveF2m.isTrinomial()) 33 { 34 ks = new int[] { curveF2m.getK1() }; 35 36 return new EllipticCurve(new ECFieldF2m(curveF2m.getM(), ks), curve.getA().toBigInteger(), curve.getB().toBigInteger(), null); 37 } 38 else 39 { 40 ks = new int[] { curveF2m.getK3(), curveF2m.getK2(), curveF2m.getK1() }; 41 42 return new EllipticCurve(new ECFieldF2m(curveF2m.getM(), ks), curve.getA().toBigInteger(), curve.getB().toBigInteger(), null); 43 } 44 } 45 } 46 convertCurve( EllipticCurve ec)47 public static ECCurve convertCurve( 48 EllipticCurve ec) 49 { 50 ECField field = ec.getField(); 51 BigInteger a = ec.getA(); 52 BigInteger b = ec.getB(); 53 54 if (field instanceof ECFieldFp) 55 { 56 return new ECCurve.Fp(((ECFieldFp)field).getP(), a, b); 57 } 58 else 59 { 60 ECFieldF2m fieldF2m = (ECFieldF2m)field; 61 int m = fieldF2m.getM(); 62 int ks[] = ECUtil.convertMidTerms(fieldF2m.getMidTermsOfReductionPolynomial()); 63 return new ECCurve.F2m(m, ks[0], ks[1], ks[2], a, b); 64 } 65 } 66 convertSpec( EllipticCurve ellipticCurve, org.bouncycastle.jce.spec.ECParameterSpec spec)67 public static ECParameterSpec convertSpec( 68 EllipticCurve ellipticCurve, 69 org.bouncycastle.jce.spec.ECParameterSpec spec) 70 { 71 if (spec instanceof ECNamedCurveParameterSpec) 72 { 73 return new ECNamedCurveSpec( 74 ((ECNamedCurveParameterSpec)spec).getName(), 75 ellipticCurve, 76 new ECPoint( 77 spec.getG().getAffineXCoord().toBigInteger(), 78 spec.getG().getAffineYCoord().toBigInteger()), 79 spec.getN(), 80 spec.getH()); 81 } 82 else 83 { 84 return new ECParameterSpec( 85 ellipticCurve, 86 new ECPoint( 87 spec.getG().getAffineXCoord().toBigInteger(), 88 spec.getG().getAffineYCoord().toBigInteger()), 89 spec.getN(), 90 spec.getH().intValue()); 91 } 92 } 93 convertSpec( ECParameterSpec ecSpec, boolean withCompression)94 public static org.bouncycastle.jce.spec.ECParameterSpec convertSpec( 95 ECParameterSpec ecSpec, 96 boolean withCompression) 97 { 98 ECCurve curve = convertCurve(ecSpec.getCurve()); 99 100 return new org.bouncycastle.jce.spec.ECParameterSpec( 101 curve, 102 convertPoint(curve, ecSpec.getGenerator(), withCompression), 103 ecSpec.getOrder(), 104 BigInteger.valueOf(ecSpec.getCofactor()), 105 ecSpec.getCurve().getSeed()); 106 } 107 convertPoint( ECParameterSpec ecSpec, ECPoint point, boolean withCompression)108 public static org.bouncycastle.math.ec.ECPoint convertPoint( 109 ECParameterSpec ecSpec, 110 ECPoint point, 111 boolean withCompression) 112 { 113 return convertPoint(convertCurve(ecSpec.getCurve()), point, withCompression); 114 } 115 convertPoint( ECCurve curve, ECPoint point, boolean withCompression)116 public static org.bouncycastle.math.ec.ECPoint convertPoint( 117 ECCurve curve, 118 ECPoint point, 119 boolean withCompression) 120 { 121 return curve.createPoint(point.getAffineX(), point.getAffineY(), withCompression); 122 } 123 } 124