J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 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. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | * |
| 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 21 | * have any questions. |
| 22 | */ |
| 23 | |
| 24 | import java.io.InputStream; |
| 25 | import java.io.IOException; |
| 26 | import java.security.Key; |
| 27 | import java.security.KeyStore; |
| 28 | import java.security.KeyStoreException; |
| 29 | import java.security.PublicKey; |
| 30 | import java.security.cert.Certificate; |
| 31 | import java.security.cert.CertificateFactory; |
| 32 | import java.security.cert.CertSelector; |
| 33 | import java.security.cert.X509Certificate; |
| 34 | import java.security.cert.X509CertSelector; |
| 35 | import java.util.*; |
| 36 | import javax.security.auth.x500.X500Principal; |
| 37 | import javax.xml.crypto.*; |
| 38 | import javax.xml.crypto.dsig.*; |
| 39 | import javax.xml.crypto.dom.*; |
| 40 | import javax.xml.crypto.dsig.keyinfo.*; |
| 41 | |
| 42 | import org.jcp.xml.dsig.internal.dom.DOMRetrievalMethod; |
| 43 | |
| 44 | /** |
| 45 | * A <code>KeySelector</code> that returns {@link PublicKey}s. If the |
| 46 | * selector is created as trusted, it only returns public keys of trusted |
| 47 | * {@link X509Certificate}s stored in a {@link KeyStore}. Otherwise, it |
| 48 | * returns trusted or untrusted public keys (it doesn't care as long |
| 49 | * as it finds one). |
| 50 | * |
| 51 | * <p>This <code>KeySelector</code> uses the specified <code>KeyStore</code> |
| 52 | * to find a trusted <code>X509Certificate</code> that matches information |
| 53 | * specified in the {@link KeyInfo} passed to the {@link #select} method. |
| 54 | * The public key from the first match is returned. If no match, |
| 55 | * <code>null</code> is returned. See the <code>select</code> method for more |
| 56 | * information. |
| 57 | * |
| 58 | * @author Sean Mullan |
| 59 | */ |
| 60 | class X509KeySelector extends KeySelector { |
| 61 | |
| 62 | private KeyStore ks; |
| 63 | private boolean trusted = true; |
| 64 | |
| 65 | /** |
| 66 | * Creates a trusted <code>X509KeySelector</code>. |
| 67 | * |
| 68 | * @param keyStore the keystore |
| 69 | * @throws KeyStoreException if the keystore has not been initialized |
| 70 | * @throws NullPointerException if <code>keyStore</code> is |
| 71 | * <code>null</code> |
| 72 | */ |
| 73 | X509KeySelector(KeyStore keyStore) throws KeyStoreException { |
| 74 | this(keyStore, true); |
| 75 | } |
| 76 | |
| 77 | X509KeySelector(KeyStore keyStore, boolean trusted) |
| 78 | throws KeyStoreException { |
| 79 | if (keyStore == null) { |
| 80 | throw new NullPointerException("keyStore is null"); |
| 81 | } |
| 82 | this.trusted = trusted; |
| 83 | this.ks = keyStore; |
| 84 | // test to see if KeyStore has been initialized |
| 85 | this.ks.size(); |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Finds a key from the keystore satisfying the specified constraints. |
| 90 | * |
| 91 | * <p>This method compares data contained in {@link KeyInfo} entries |
| 92 | * with information stored in the <code>KeyStore</code>. The implementation |
| 93 | * iterates over the KeyInfo types and returns the first {@link PublicKey} |
| 94 | * of an X509Certificate in the keystore that is compatible with the |
| 95 | * specified AlgorithmMethod according to the following rules for each |
| 96 | * keyinfo type: |
| 97 | * |
| 98 | * X509Data X509Certificate: if it contains a <code>KeyUsage</code> |
| 99 | * extension that asserts the <code>digitalSignature</code> bit and |
| 100 | * matches an <code>X509Certificate</code> in the <code>KeyStore</code>. |
| 101 | * X509Data X509IssuerSerial: if the serial number and issuer DN match an |
| 102 | * <code>X509Certificate</code> in the <code>KeyStore</code>. |
| 103 | * X509Data X509SubjectName: if the subject DN matches an |
| 104 | * <code>X509Certificate</code> in the <code>KeyStore</code>. |
| 105 | * X509Data X509SKI: if the subject key identifier matches an |
| 106 | * <code>X509Certificate</code> in the <code>KeyStore</code>. |
| 107 | * KeyName: if the keyname matches an alias in the <code>KeyStore</code>. |
| 108 | * RetrievalMethod: supports rawX509Certificate and X509Data types. If |
| 109 | * rawX509Certificate type, it must match an <code>X509Certificate</code> |
| 110 | * in the <code>KeyStore</code>. |
| 111 | * |
| 112 | * @param keyInfo a <code>KeyInfo</code> (may be <code>null</code>) |
| 113 | * @param purpose the key's purpose |
| 114 | * @param method the algorithm method that this key is to be used for. |
| 115 | * Only keys that are compatible with the algorithm and meet the |
| 116 | * constraints of the specified algorithm should be returned. |
| 117 | * @param an <code>XMLCryptoContext</code> that may contain additional |
| 118 | * useful information for finding an appropriate key |
| 119 | * @return a key selector result |
| 120 | * @throws KeySelectorException if an exceptional condition occurs while |
| 121 | * attempting to find a key. Note that an inability to find a key is not |
| 122 | * considered an exception (<code>null</code> should be |
| 123 | * returned in that case). However, an error condition (ex: network |
| 124 | * communications failure) that prevented the <code>KeySelector</code> |
| 125 | * from finding a potential key should be considered an exception. |
| 126 | * @throws ClassCastException if the data type of <code>method</code> |
| 127 | * is not supported by this key selector |
| 128 | */ |
| 129 | public KeySelectorResult select(KeyInfo keyInfo, |
| 130 | KeySelector.Purpose purpose, AlgorithmMethod method, |
| 131 | XMLCryptoContext context) throws KeySelectorException { |
| 132 | |
| 133 | SignatureMethod sm = (SignatureMethod) method; |
| 134 | |
| 135 | try { |
| 136 | // return null if keyinfo is null or keystore is empty |
| 137 | if (keyInfo == null || ks.size() == 0) { |
| 138 | return new SimpleKeySelectorResult(null); |
| 139 | } |
| 140 | |
| 141 | // Iterate through KeyInfo types |
| 142 | Iterator i = keyInfo.getContent().iterator(); |
| 143 | while (i.hasNext()) { |
| 144 | XMLStructure kiType = (XMLStructure) i.next(); |
| 145 | // check X509Data |
| 146 | if (kiType instanceof X509Data) { |
| 147 | X509Data xd = (X509Data) kiType; |
| 148 | KeySelectorResult ksr = x509DataSelect(xd, sm); |
| 149 | if (ksr != null) { |
| 150 | return ksr; |
| 151 | } |
| 152 | // check KeyName |
| 153 | } else if (kiType instanceof KeyName) { |
| 154 | KeyName kn = (KeyName) kiType; |
| 155 | Certificate cert = ks.getCertificate(kn.getName()); |
| 156 | if (cert != null && algEquals(sm.getAlgorithm(), |
| 157 | cert.getPublicKey().getAlgorithm())) { |
| 158 | return new SimpleKeySelectorResult(cert.getPublicKey()); |
| 159 | } |
| 160 | // check RetrievalMethod |
| 161 | } else if (kiType instanceof RetrievalMethod) { |
| 162 | RetrievalMethod rm = (RetrievalMethod) kiType; |
| 163 | try { |
| 164 | KeySelectorResult ksr = null; |
| 165 | if (rm.getType().equals |
| 166 | (X509Data.RAW_X509_CERTIFICATE_TYPE)) { |
| 167 | OctetStreamData data = (OctetStreamData) |
| 168 | rm.dereference(context); |
| 169 | CertificateFactory cf = |
| 170 | CertificateFactory.getInstance("X.509"); |
| 171 | X509Certificate cert = (X509Certificate) |
| 172 | cf.generateCertificate(data.getOctetStream()); |
| 173 | ksr = certSelect(cert, sm); |
| 174 | } else if (rm.getType().equals(X509Data.TYPE)) { |
| 175 | X509Data xd = (X509Data) ((DOMRetrievalMethod) rm). |
| 176 | dereferenceAsXMLStructure(context); |
| 177 | ksr = x509DataSelect(xd, sm); |
| 178 | } else { |
| 179 | // skip; keyinfo type is not supported |
| 180 | continue; |
| 181 | } |
| 182 | if (ksr != null) { |
| 183 | return ksr; |
| 184 | } |
| 185 | } catch (Exception e) { |
| 186 | throw new KeySelectorException(e); |
| 187 | } |
| 188 | } |
| 189 | } |
| 190 | } catch (KeyStoreException kse) { |
| 191 | // throw exception if keystore is uninitialized |
| 192 | throw new KeySelectorException(kse); |
| 193 | } |
| 194 | |
| 195 | // return null since no match could be found |
| 196 | return new SimpleKeySelectorResult(null); |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * Searches the specified keystore for a certificate that matches the |
| 201 | * criteria specified in the CertSelector. |
| 202 | * |
| 203 | * @return a KeySelectorResult containing the cert's public key if there |
| 204 | * is a match; otherwise null |
| 205 | */ |
| 206 | private KeySelectorResult keyStoreSelect(CertSelector cs) |
| 207 | throws KeyStoreException { |
| 208 | Enumeration aliases = ks.aliases(); |
| 209 | while (aliases.hasMoreElements()) { |
| 210 | String alias = (String) aliases.nextElement(); |
| 211 | Certificate cert = ks.getCertificate(alias); |
| 212 | if (cert != null && cs.match(cert)) { |
| 213 | return new SimpleKeySelectorResult(cert.getPublicKey()); |
| 214 | } |
| 215 | } |
| 216 | return null; |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * Searches the specified keystore for a certificate that matches the |
| 221 | * specified X509Certificate and contains a public key that is compatible |
| 222 | * with the specified SignatureMethod. |
| 223 | * |
| 224 | * @return a KeySelectorResult containing the cert's public key if there |
| 225 | * is a match; otherwise null |
| 226 | */ |
| 227 | private KeySelectorResult certSelect(X509Certificate xcert, |
| 228 | SignatureMethod sm) throws KeyStoreException { |
| 229 | // skip non-signer certs |
| 230 | boolean[] keyUsage = xcert.getKeyUsage(); |
| 231 | if (keyUsage != null && keyUsage[0] == false) { |
| 232 | return null; |
| 233 | } |
| 234 | String alias = ks.getCertificateAlias(xcert); |
| 235 | if (alias != null) { |
| 236 | PublicKey pk = ks.getCertificate(alias).getPublicKey(); |
| 237 | // make sure algorithm is compatible with method |
| 238 | if (algEquals(sm.getAlgorithm(), pk.getAlgorithm())) { |
| 239 | return new SimpleKeySelectorResult(pk); |
| 240 | } |
| 241 | } |
| 242 | return null; |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * Returns an OID of a public-key algorithm compatible with the specified |
| 247 | * signature algorithm URI. |
| 248 | */ |
| 249 | private String getPKAlgorithmOID(String algURI) { |
| 250 | if (algURI.equalsIgnoreCase(SignatureMethod.DSA_SHA1)) { |
| 251 | return "1.2.840.10040.4.1"; |
| 252 | } else if (algURI.equalsIgnoreCase(SignatureMethod.RSA_SHA1)) { |
| 253 | return "1.2.840.113549.1.1"; |
| 254 | } else { |
| 255 | return null; |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * A simple KeySelectorResult containing a public key. |
| 261 | */ |
| 262 | private static class SimpleKeySelectorResult implements KeySelectorResult { |
| 263 | private final Key key; |
| 264 | SimpleKeySelectorResult(Key key) { this.key = key; } |
| 265 | public Key getKey() { return key; } |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Checks if a JCA/JCE public key algorithm name is compatible with |
| 270 | * the specified signature algorithm URI. |
| 271 | */ |
| 272 | //@@@FIXME: this should also work for key types other than DSA/RSA |
| 273 | private boolean algEquals(String algURI, String algName) { |
| 274 | if (algName.equalsIgnoreCase("DSA") && |
| 275 | algURI.equalsIgnoreCase(SignatureMethod.DSA_SHA1)) { |
| 276 | return true; |
| 277 | } else if (algName.equalsIgnoreCase("RSA") && |
| 278 | algURI.equalsIgnoreCase(SignatureMethod.RSA_SHA1)) { |
| 279 | return true; |
| 280 | } else { |
| 281 | return false; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * Searches the specified keystore for a certificate that matches an |
| 287 | * entry of the specified X509Data and contains a public key that is |
| 288 | * compatible with the specified SignatureMethod. |
| 289 | * |
| 290 | * @return a KeySelectorResult containing the cert's public key if there |
| 291 | * is a match; otherwise null |
| 292 | */ |
| 293 | private KeySelectorResult x509DataSelect(X509Data xd, SignatureMethod sm) |
| 294 | throws KeyStoreException, KeySelectorException { |
| 295 | |
| 296 | // convert signature algorithm to compatible public-key alg OID |
| 297 | String algOID = getPKAlgorithmOID(sm.getAlgorithm()); |
| 298 | X509CertSelector subjectcs = new X509CertSelector(); |
| 299 | try { |
| 300 | subjectcs.setSubjectPublicKeyAlgID(algOID); |
| 301 | } catch (IOException ioe) { |
| 302 | throw new KeySelectorException(ioe); |
| 303 | } |
| 304 | Collection certs = new ArrayList(); |
| 305 | |
| 306 | Iterator xi = xd.getContent().iterator(); |
| 307 | while (xi.hasNext()) { |
| 308 | Object o = xi.next(); |
| 309 | // check X509IssuerSerial |
| 310 | if (o instanceof X509IssuerSerial) { |
| 311 | X509IssuerSerial xis = (X509IssuerSerial) o; |
| 312 | try { |
| 313 | subjectcs.setSerialNumber(xis.getSerialNumber()); |
| 314 | String issuer = new X500Principal(xis.getIssuerName()).getName(); |
| 315 | // strip off newline |
| 316 | if (issuer.endsWith("\n")) { |
| 317 | issuer = new String |
| 318 | (issuer.toCharArray(), 0, issuer.length()-1); |
| 319 | } |
| 320 | subjectcs.setIssuer(issuer); |
| 321 | } catch (IOException ioe) { |
| 322 | throw new KeySelectorException(ioe); |
| 323 | } |
| 324 | // check X509SubjectName |
| 325 | } else if (o instanceof String) { |
| 326 | String sn = (String) o; |
| 327 | try { |
| 328 | String subject = new X500Principal(sn).getName(); |
| 329 | // strip off newline |
| 330 | if (subject.endsWith("\n")) { |
| 331 | subject = new String |
| 332 | (subject.toCharArray(), 0, subject.length()-1); |
| 333 | } |
| 334 | subjectcs.setSubject(subject); |
| 335 | } catch (IOException ioe) { |
| 336 | throw new KeySelectorException(ioe); |
| 337 | } |
| 338 | // check X509SKI |
| 339 | } else if (o instanceof byte[]) { |
| 340 | byte[] ski = (byte[]) o; |
| 341 | // DER-encode ski - required by X509CertSelector |
| 342 | byte[] encodedSki = new byte[ski.length+2]; |
| 343 | encodedSki[0] = 0x04; // OCTET STRING tag value |
| 344 | encodedSki[1] = (byte) ski.length; // length |
| 345 | System.arraycopy(ski, 0, encodedSki, 2, ski.length); |
| 346 | subjectcs.setSubjectKeyIdentifier(encodedSki); |
| 347 | } else if (o instanceof X509Certificate) { |
| 348 | certs.add((X509Certificate) o); |
| 349 | // check X509CRL |
| 350 | // not supported: should use CertPath API |
| 351 | } else { |
| 352 | // skip all other entries |
| 353 | continue; |
| 354 | } |
| 355 | } |
| 356 | KeySelectorResult ksr = keyStoreSelect(subjectcs); |
| 357 | if (ksr != null) { |
| 358 | return ksr; |
| 359 | } |
| 360 | if (!certs.isEmpty() && !trusted) { |
| 361 | // try to find public key in certs in X509Data |
| 362 | Iterator i = certs.iterator(); |
| 363 | while (i.hasNext()) { |
| 364 | X509Certificate cert = (X509Certificate) i.next(); |
| 365 | if (subjectcs.match(cert)) { |
| 366 | return new SimpleKeySelectorResult(cert.getPublicKey()); |
| 367 | } |
| 368 | } |
| 369 | } |
| 370 | return null; |
| 371 | } |
| 372 | } |