J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.security.ec; |
| 27 | |
| 28 | import java.io.IOException; |
| 29 | import java.math.BigInteger; |
| 30 | |
| 31 | import java.security.*; |
| 32 | import java.security.spec.*; |
| 33 | |
| 34 | import sun.security.util.*; |
| 35 | |
| 36 | /** |
| 37 | * This class implements encoding and decoding of Elliptic Curve parameters |
| 38 | * as specified in RFC 3279. |
| 39 | * |
| 40 | * However, only named curves are currently supported. |
| 41 | * |
| 42 | * ASN.1 from RFC 3279 follows. Note that X9.62 (2005) has added some additional |
| 43 | * options. |
| 44 | * |
| 45 | * <pre> |
| 46 | * EcpkParameters ::= CHOICE { |
| 47 | * ecParameters ECParameters, |
| 48 | * namedCurve OBJECT IDENTIFIER, |
| 49 | * implicitlyCA NULL } |
| 50 | * |
| 51 | * ECParameters ::= SEQUENCE { |
| 52 | * version ECPVer, -- version is always 1 |
| 53 | * fieldID FieldID, -- identifies the finite field over |
| 54 | * -- which the curve is defined |
| 55 | * curve Curve, -- coefficients a and b of the |
| 56 | * -- elliptic curve |
| 57 | * base ECPoint, -- specifies the base point P |
| 58 | * -- on the elliptic curve |
| 59 | * order INTEGER, -- the order n of the base point |
| 60 | * cofactor INTEGER OPTIONAL -- The integer h = #E(Fq)/n |
| 61 | * } |
| 62 | * |
| 63 | * ECPVer ::= INTEGER {ecpVer1(1)} |
| 64 | * |
| 65 | * Curve ::= SEQUENCE { |
| 66 | * a FieldElement, |
| 67 | * b FieldElement, |
| 68 | * seed BIT STRING OPTIONAL } |
| 69 | * |
| 70 | * FieldElement ::= OCTET STRING |
| 71 | * |
| 72 | * ECPoint ::= OCTET STRING |
| 73 | * </pre> |
| 74 | * |
| 75 | * @since 1.6 |
| 76 | * @author Andreas Sterbenz |
| 77 | */ |
| 78 | public final class ECParameters extends AlgorithmParametersSpi { |
| 79 | |
| 80 | public ECParameters() { |
| 81 | // empty |
| 82 | } |
| 83 | |
| 84 | // Used by SunPKCS11 and SunJSSE. |
| 85 | public static ECPoint decodePoint(byte[] data, EllipticCurve curve) |
| 86 | throws IOException { |
| 87 | if ((data.length == 0) || (data[0] != 4)) { |
| 88 | throw new IOException("Only uncompressed point format supported"); |
| 89 | } |
| 90 | int n = (curve.getField().getFieldSize() + 7 ) >> 3; |
| 91 | if (data.length != (n * 2) + 1) { |
| 92 | throw new IOException("Point does not match field size"); |
| 93 | } |
| 94 | byte[] xb = new byte[n]; |
| 95 | byte[] yb = new byte[n]; |
| 96 | System.arraycopy(data, 1, xb, 0, n); |
| 97 | System.arraycopy(data, n + 1, yb, 0, n); |
| 98 | return new ECPoint(new BigInteger(1, xb), new BigInteger(1, yb)); |
| 99 | } |
| 100 | |
| 101 | // Used by SunPKCS11 and SunJSSE. |
| 102 | public static byte[] encodePoint(ECPoint point, EllipticCurve curve) { |
| 103 | // get field size in bytes (rounding up) |
| 104 | int n = (curve.getField().getFieldSize() + 7) >> 3; |
| 105 | byte[] xb = trimZeroes(point.getAffineX().toByteArray()); |
| 106 | byte[] yb = trimZeroes(point.getAffineY().toByteArray()); |
| 107 | if ((xb.length > n) || (yb.length > n)) { |
| 108 | throw new RuntimeException |
| 109 | ("Point coordinates do not match field size"); |
| 110 | } |
| 111 | byte[] b = new byte[1 + (n << 1)]; |
| 112 | b[0] = 4; // uncompressed |
| 113 | System.arraycopy(xb, 0, b, n - xb.length + 1, xb.length); |
| 114 | System.arraycopy(yb, 0, b, b.length - yb.length, yb.length); |
| 115 | return b; |
| 116 | } |
| 117 | |
| 118 | // Copied from the SunPKCS11 code - should be moved to a common location. |
| 119 | // trim leading (most significant) zeroes from the result |
| 120 | static byte[] trimZeroes(byte[] b) { |
| 121 | int i = 0; |
| 122 | while ((i < b.length - 1) && (b[i] == 0)) { |
| 123 | i++; |
| 124 | } |
| 125 | if (i == 0) { |
| 126 | return b; |
| 127 | } |
| 128 | byte[] t = new byte[b.length - i]; |
| 129 | System.arraycopy(b, i, t, 0, t.length); |
| 130 | return t; |
| 131 | } |
| 132 | |
| 133 | // Convert the given ECParameterSpec object to a NamedCurve object. |
| 134 | // If params does not represent a known named curve, return null. |
| 135 | // Used by SunPKCS11. |
| 136 | public static NamedCurve getNamedCurve(ECParameterSpec params) { |
| 137 | if ((params instanceof NamedCurve) || (params == null)) { |
| 138 | return (NamedCurve)params; |
| 139 | } |
| 140 | // This is a hack to allow SunJSSE to work with 3rd party crypto |
| 141 | // providers for ECC and not just SunPKCS11. |
| 142 | // This can go away once we decide how to expose curve names in the |
| 143 | // public API. |
| 144 | // Note that it assumes that the 3rd party provider encodes named |
| 145 | // curves using the short form, not explicitly. If it did that, then |
| 146 | // the SunJSSE TLS ECC extensions are wrong, which could lead to |
| 147 | // interoperability problems. |
| 148 | int fieldSize = params.getCurve().getField().getFieldSize(); |
| 149 | for (ECParameterSpec namedCurve : NamedCurve.knownECParameterSpecs()) { |
| 150 | // ECParameterSpec does not define equals, so check all the |
| 151 | // components ourselves. |
| 152 | // Quick field size check first |
| 153 | if (namedCurve.getCurve().getField().getFieldSize() != fieldSize) { |
| 154 | continue; |
| 155 | } |
| 156 | if (namedCurve.getCurve().equals(params.getCurve()) == false) { |
| 157 | continue; |
| 158 | } |
| 159 | if (namedCurve.getGenerator().equals(params.getGenerator()) == false) { |
| 160 | continue; |
| 161 | } |
| 162 | if (namedCurve.getOrder().equals(params.getOrder()) == false) { |
| 163 | continue; |
| 164 | } |
| 165 | if (namedCurve.getCofactor() != params.getCofactor()) { |
| 166 | continue; |
| 167 | } |
| 168 | // everything matches our named curve, return it |
| 169 | return (NamedCurve)namedCurve; |
| 170 | } |
| 171 | // no match found |
| 172 | return null; |
| 173 | } |
| 174 | |
| 175 | // Used by SunJSSE. |
| 176 | public static String getCurveName(ECParameterSpec params) { |
| 177 | NamedCurve curve = getNamedCurve(params); |
| 178 | return (curve == null) ? null : curve.getObjectIdentifier().toString(); |
| 179 | } |
| 180 | |
| 181 | // Used by SunPKCS11. |
| 182 | public static byte[] encodeParameters(ECParameterSpec params) { |
| 183 | NamedCurve curve = getNamedCurve(params); |
| 184 | if (curve == null) { |
| 185 | throw new RuntimeException("Not a known named curve: " + params); |
| 186 | } |
| 187 | return curve.getEncoded(); |
| 188 | } |
| 189 | |
| 190 | // Used by SunPKCS11. |
| 191 | public static ECParameterSpec decodeParameters(byte[] params) throws IOException { |
| 192 | DerValue encodedParams = new DerValue(params); |
| 193 | if (encodedParams.tag == DerValue.tag_ObjectId) { |
| 194 | ObjectIdentifier oid = encodedParams.getOID(); |
| 195 | ECParameterSpec spec = NamedCurve.getECParameterSpec(oid); |
| 196 | if (spec == null) { |
| 197 | throw new IOException("Unknown named curve: " + oid); |
| 198 | } |
| 199 | return spec; |
| 200 | } |
| 201 | |
| 202 | throw new IOException("Only named ECParameters supported"); |
| 203 | |
| 204 | // The code below is incomplete. |
| 205 | // It is left as a starting point for a complete parsing implementation. |
| 206 | |
| 207 | /* |
| 208 | if (encodedParams.tag != DerValue.tag_Sequence) { |
| 209 | throw new IOException("Unsupported EC parameters, tag: " + encodedParams.tag); |
| 210 | } |
| 211 | |
| 212 | encodedParams.data.reset(); |
| 213 | |
| 214 | DerInputStream in = encodedParams.data; |
| 215 | |
| 216 | int version = in.getInteger(); |
| 217 | if (version != 1) { |
| 218 | throw new IOException("Unsupported EC parameters version: " + version); |
| 219 | } |
| 220 | ECField field = parseField(in); |
| 221 | EllipticCurve curve = parseCurve(in, field); |
| 222 | ECPoint point = parsePoint(in, curve); |
| 223 | |
| 224 | BigInteger order = in.getBigInteger(); |
| 225 | int cofactor = 0; |
| 226 | |
| 227 | if (in.available() != 0) { |
| 228 | cofactor = in.getInteger(); |
| 229 | } |
| 230 | |
| 231 | // XXX HashAlgorithm optional |
| 232 | |
| 233 | if (encodedParams.data.available() != 0) { |
| 234 | throw new IOException("encoded params have " + |
| 235 | encodedParams.data.available() + |
| 236 | " extra bytes"); |
| 237 | } |
| 238 | |
| 239 | return new ECParameterSpec(curve, point, order, cofactor); |
| 240 | */ |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | private static final ObjectIdentifier fieldTypePrime = |
| 245 | ObjectIdentifier.newInternal(new int[] {1, 2, 840, 10045, 1, 1}); |
| 246 | |
| 247 | private static final ObjectIdentifier fieldTypeChar2 = |
| 248 | ObjectIdentifier.newInternal(new int[] {1, 2, 840, 10045, 1, 2}); |
| 249 | |
| 250 | private static ECField parseField(DerInputStream in) throws IOException { |
| 251 | DerValue v = in.getDerValue(); |
| 252 | ObjectIdentifier oid = v.data.getOID(); |
| 253 | if (oid.equals(fieldTypePrime) == false) { |
| 254 | throw new IOException("Only prime fields supported: " + oid); |
| 255 | } |
| 256 | BigInteger fieldSize = v.data.getBigInteger(); |
| 257 | return new ECFieldFp(fieldSize); |
| 258 | } |
| 259 | |
| 260 | private static EllipticCurve parseCurve(DerInputStream in, ECField field) |
| 261 | throws IOException { |
| 262 | DerValue v = in.getDerValue(); |
| 263 | byte[] ab = v.data.getOctetString(); |
| 264 | byte[] bb = v.data.getOctetString(); |
| 265 | return new EllipticCurve(field, new BigInteger(1, ab), new BigInteger(1, bb)); |
| 266 | } |
| 267 | |
| 268 | private static ECPoint parsePoint(DerInputStream in, EllipticCurve curve) |
| 269 | throws IOException { |
| 270 | byte[] data = in.getOctetString(); |
| 271 | return decodePoint(data, curve); |
| 272 | } |
| 273 | */ |
| 274 | |
| 275 | // used by ECPublicKeyImpl and ECPrivateKeyImpl |
| 276 | static AlgorithmParameters getAlgorithmParameters(ECParameterSpec spec) |
| 277 | throws InvalidKeyException { |
| 278 | try { |
| 279 | AlgorithmParameters params = AlgorithmParameters.getInstance |
| 280 | ("EC", ECKeyFactory.ecInternalProvider); |
| 281 | params.init(spec); |
| 282 | return params; |
| 283 | } catch (GeneralSecurityException e) { |
| 284 | throw new InvalidKeyException("EC parameters error", e); |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | // AlgorithmParameterSpi methods |
| 289 | |
| 290 | // The parameters these AlgorithmParameters object represents. |
| 291 | // Currently, it is always an instance of NamedCurve. |
| 292 | private ECParameterSpec paramSpec; |
| 293 | |
| 294 | protected void engineInit(AlgorithmParameterSpec paramSpec) |
| 295 | throws InvalidParameterSpecException { |
| 296 | if (paramSpec instanceof ECParameterSpec) { |
| 297 | this.paramSpec = getNamedCurve((ECParameterSpec)paramSpec); |
| 298 | if (this.paramSpec == null) { |
| 299 | throw new InvalidParameterSpecException |
| 300 | ("Not a supported named curve: " + paramSpec); |
| 301 | } |
| 302 | } else if (paramSpec instanceof ECGenParameterSpec) { |
| 303 | String name = ((ECGenParameterSpec)paramSpec).getName(); |
| 304 | ECParameterSpec spec = NamedCurve.getECParameterSpec(name); |
| 305 | if (spec == null) { |
| 306 | throw new InvalidParameterSpecException("Unknown curve: " + name); |
| 307 | } |
| 308 | this.paramSpec = spec; |
| 309 | } else if (paramSpec == null) { |
| 310 | throw new InvalidParameterSpecException |
| 311 | ("paramSpec must not be null"); |
| 312 | } else { |
| 313 | throw new InvalidParameterSpecException |
| 314 | ("Only ECParameterSpec and ECGenParameterSpec supported"); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | protected void engineInit(byte[] params) throws IOException { |
| 319 | paramSpec = decodeParameters(params); |
| 320 | } |
| 321 | |
| 322 | protected void engineInit(byte[] params, String decodingMethod) throws IOException { |
| 323 | engineInit(params); |
| 324 | } |
| 325 | |
| 326 | protected <T extends AlgorithmParameterSpec> T engineGetParameterSpec(Class<T> spec) |
| 327 | throws InvalidParameterSpecException { |
| 328 | if (spec.isAssignableFrom(ECParameterSpec.class)) { |
| 329 | return (T)paramSpec; |
| 330 | } else if (spec.isAssignableFrom(ECGenParameterSpec.class)) { |
| 331 | return (T)new ECGenParameterSpec(getCurveName(paramSpec)); |
| 332 | } else { |
| 333 | throw new InvalidParameterSpecException |
| 334 | ("Only ECParameterSpec and ECGenParameterSpec supported"); |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | protected byte[] engineGetEncoded() throws IOException { |
| 339 | return encodeParameters(paramSpec); |
| 340 | } |
| 341 | |
| 342 | protected byte[] engineGetEncoded(String encodingMethod) throws IOException { |
| 343 | return engineGetEncoded(); |
| 344 | } |
| 345 | |
| 346 | protected String engineToString() { |
| 347 | return paramSpec.toString(); |
| 348 | } |
| 349 | } |