1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.conscrypt; 18 19 import java.math.BigInteger; 20 import java.security.InvalidAlgorithmParameterException; 21 import java.security.InvalidParameterException; 22 import java.security.spec.ECField; 23 import java.security.spec.ECFieldF2m; 24 import java.security.spec.ECFieldFp; 25 import java.security.spec.ECParameterSpec; 26 import java.security.spec.ECPoint; 27 import java.security.spec.EllipticCurve; 28 29 public final class OpenSSLECGroupContext { 30 private final long groupCtx; 31 32 public OpenSSLECGroupContext(long groupCtx) { 33 this.groupCtx = groupCtx; 34 } 35 36 public static OpenSSLECGroupContext getCurveByName(String curveName) { 37 // Workaround for OpenSSL not supporting SECG names for NIST P-192 and P-256 38 // (aka ANSI X9.62 prime192v1 and prime256v1) curve names. 39 if ("secp256r1".equals(curveName)) { 40 curveName = "prime256v1"; 41 } else if ("secp192r1".equals(curveName)) { 42 curveName = "prime192v1"; 43 } 44 45 final long ctx = NativeCrypto.EC_GROUP_new_by_curve_name(curveName); 46 if (ctx == 0) { 47 return null; 48 } 49 50 NativeCrypto.EC_GROUP_set_point_conversion_form(ctx, 51 NativeCrypto.POINT_CONVERSION_UNCOMPRESSED); 52 NativeCrypto.EC_GROUP_set_asn1_flag(ctx, NativeCrypto.OPENSSL_EC_NAMED_CURVE); 53 54 return new OpenSSLECGroupContext(ctx); 55 } 56 57 public static OpenSSLECGroupContext getInstance(int type, BigInteger p, BigInteger a, 58 BigInteger b, BigInteger x, BigInteger y, BigInteger n, BigInteger h) { 59 final long ctx = NativeCrypto.EC_GROUP_new_curve(type, p.toByteArray(), a.toByteArray(), 60 b.toByteArray()); 61 if (ctx == 0) { 62 return null; 63 } 64 65 NativeCrypto.EC_GROUP_set_point_conversion_form(ctx, 66 NativeCrypto.POINT_CONVERSION_UNCOMPRESSED); 67 68 OpenSSLECGroupContext group = new OpenSSLECGroupContext(ctx); 69 70 OpenSSLECPointContext generator = new OpenSSLECPointContext(group, 71 NativeCrypto.EC_POINT_new(ctx)); 72 73 NativeCrypto.EC_POINT_set_affine_coordinates(ctx, generator.getContext(), 74 x.toByteArray(), y.toByteArray()); 75 76 NativeCrypto.EC_GROUP_set_generator(ctx, generator.getContext(), n.toByteArray(), 77 h.toByteArray()); 78 79 return group; 80 } 81 82 @Override 83 protected void finalize() throws Throwable { 84 try { 85 if (groupCtx != 0) { 86 NativeCrypto.EC_GROUP_clear_free(groupCtx); 87 } 88 } finally { 89 super.finalize(); 90 } 91 } 92 93 @Override 94 public boolean equals(Object o) { 95 if (!(o instanceof OpenSSLECGroupContext)) { 96 return false; 97 } 98 99 final OpenSSLECGroupContext other = (OpenSSLECGroupContext) o; 100 return NativeCrypto.EC_GROUP_cmp(groupCtx, other.groupCtx); 101 } 102 103 @Override 104 public int hashCode() { 105 // TODO Auto-generated method stub 106 return super.hashCode(); 107 } 108 109 public long getContext() { 110 return groupCtx; 111 } 112 113 public static OpenSSLECGroupContext getInstance(ECParameterSpec params) 114 throws InvalidAlgorithmParameterException { 115 final String curveName = Platform.getCurveName(params); 116 if (curveName != null) { 117 return OpenSSLECGroupContext.getCurveByName(curveName); 118 } 119 120 final EllipticCurve curve = params.getCurve(); 121 final ECField field = curve.getField(); 122 123 final int type; 124 final BigInteger p; 125 if (field instanceof ECFieldFp) { 126 type = NativeCrypto.EC_CURVE_GFP; 127 p = ((ECFieldFp) field).getP(); 128 } else if (field instanceof ECFieldF2m) { 129 type = NativeCrypto.EC_CURVE_GF2M; 130 p = ((ECFieldF2m) field).getReductionPolynomial(); 131 } else { 132 throw new InvalidParameterException("unhandled field class " 133 + field.getClass().getName()); 134 } 135 136 final ECPoint generator = params.getGenerator(); 137 return OpenSSLECGroupContext.getInstance(type, p, curve.getA(), curve.getB(), 138 generator.getAffineX(), generator.getAffineY(), params.getOrder(), 139 BigInteger.valueOf(params.getCofactor())); 140 } 141 142 public ECParameterSpec getECParameterSpec() { 143 final String curveName = NativeCrypto.EC_GROUP_get_curve_name(groupCtx); 144 145 final byte[][] curveParams = NativeCrypto.EC_GROUP_get_curve(groupCtx); 146 final BigInteger p = new BigInteger(curveParams[0]); 147 final BigInteger a = new BigInteger(curveParams[1]); 148 final BigInteger b = new BigInteger(curveParams[2]); 149 150 final ECField field; 151 final int type = NativeCrypto.get_EC_GROUP_type(groupCtx); 152 if (type == NativeCrypto.EC_CURVE_GFP) { 153 field = new ECFieldFp(p); 154 } else if (type == NativeCrypto.EC_CURVE_GF2M) { 155 field = new ECFieldF2m(p.bitLength() - 1, p); 156 } else { 157 throw new RuntimeException("unknown curve type " + type); 158 } 159 160 final EllipticCurve curve = new EllipticCurve(field, a, b); 161 162 final OpenSSLECPointContext generatorCtx = new OpenSSLECPointContext(this, 163 NativeCrypto.EC_GROUP_get_generator(groupCtx)); 164 final ECPoint generator = generatorCtx.getECPoint(); 165 166 final BigInteger order = new BigInteger(NativeCrypto.EC_GROUP_get_order(groupCtx)); 167 final BigInteger cofactor = new BigInteger(NativeCrypto.EC_GROUP_get_cofactor(groupCtx)); 168 169 ECParameterSpec spec = new ECParameterSpec(curve, generator, order, cofactor.intValue()); 170 Platform.setCurveName(spec, curveName); 171 return spec; 172 } 173 } 174
