Context.java 13.8 KB
Newer Older
W
weijun 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386
/*
 * Copyright 2008 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

import com.sun.security.auth.module.Krb5LoginModule;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import javax.security.auth.Subject;
import javax.security.auth.kerberos.KerberosKey;
import javax.security.auth.kerberos.KerberosTicket;
import javax.security.auth.login.LoginContext;
import org.ietf.jgss.GSSContext;
import org.ietf.jgss.GSSCredential;
import org.ietf.jgss.GSSException;
import org.ietf.jgss.GSSManager;
import org.ietf.jgss.GSSName;
import org.ietf.jgss.MessageProp;
import org.ietf.jgss.Oid;

/**
 * Context of a JGSS subject, encapsulating Subject and GSSContext.
 *
 * Three "constructors", which acquire the (private) credentials and fill
 * it into the Subject:
 *
 * 1. static fromJAAS(): Creates a Context using a JAAS login config entry
 * 2. static fromUserPass(): Creates a Context using a username and a password
 * 3. delegated(): A new context which uses the delegated credentials from a
 *    previously established acceptor Context
 *
 * Two context initiators, which create the GSSContext object inside:
 *
 * 1. startAsClient()
 * 2. startAsServer()
 *
 * Privileged action:
 *    doAs(): Performs an action in the name of the Subject
 *
 * Handshake process:
 *    static handShake(initiator, acceptor)
 *
 * A four-phase typical data communication which includes all four GSS
 * actions (wrap, unwrap, getMic and veryfyMiC):
 *    static transmit(message, from, to)
 */
public class Context {

    private Subject s;
    private GSSContext x;
    private boolean f;      // context established?
    private String name;
    private GSSCredential cred;     // see static method delegated().

    private Context() {}

    /**
     * Using the delegated credentials from a previous acceptor
     * @param c
     */
    public Context delegated() throws Exception {
        Context out = new Context();
        out.s = s;
        out.cred = x.getDelegCred();
        out.name = name + " as " + out.cred.getName().toString();
        return out;
    }

    /**
     * Logins with a JAAS login config entry name
     */
    public static Context fromJAAS(final String name) throws Exception {
        Context out = new Context();
        out.name = name;
        LoginContext lc = new LoginContext(name);
        lc.login();
        out.s = lc.getSubject();
        return out;
    }

    /**
     * Logins with a username and a password, using Krb5LoginModule directly
     * @param storeKey true if key should be saved, used on acceptor side
     */
    public static Context fromUserPass(String user, char[] pass, boolean storeKey) throws Exception {
        Context out = new Context();
        out.name = user;
        out.s = new Subject();
        Krb5LoginModule krb5 = new Krb5LoginModule();
        Map<String, String> map = new HashMap<String, String>();
        map.put("tryFirstPass", "true");
        if (storeKey) {
            map.put("storeKey", "true");
        }
        Map<String, Object> shared = new HashMap<String, Object>();
        shared.put("javax.security.auth.login.name", user);
        shared.put("javax.security.auth.login.password", pass);

        krb5.initialize(out.s, null, shared, map);
        krb5.login();
        krb5.commit();
        return out;
    }

    /**
     * Starts as a client
     * @param target communication peer
     * @param mech GSS mech
     * @throws java.lang.Exception
     */
    public void startAsClient(final String target, final Oid mech) throws Exception {
        doAs(new Action() {
            @Override
            public byte[] run(Context me, byte[] dummy) throws Exception {
                GSSManager m = GSSManager.getInstance();
                me.x = m.createContext(
                        target.indexOf('@') < 0 ?
                            m.createName(target, null) :
                            m.createName(target, GSSName.NT_HOSTBASED_SERVICE),
                        mech,
                        cred,
                        GSSContext.DEFAULT_LIFETIME);
                return null;
            }
        }, null);
        f = false;
    }

    /**
     * Starts as a server
     * @param mech GSS mech
     * @throws java.lang.Exception
     */
    public void startAsServer(final Oid mech) throws Exception {
        doAs(new Action() {
            @Override
            public byte[] run(Context me, byte[] dummy) throws Exception {
                GSSManager m = GSSManager.getInstance();
                me.x = m.createContext(m.createCredential(
                        null,
                        GSSCredential.INDEFINITE_LIFETIME,
                        mech,
                        GSSCredential.ACCEPT_ONLY));
                return null;
            }
        }, null);
        f = false;
    }

    /**
     * Accesses the internal GSSContext object. Currently it's used for --
     *
     * 1. calling requestXXX() before handshake
     * 2. accessing source name
     *
     * Note: If the application needs to do any privileged call on this
     * object, please use doAs(). Otherwise, it can be done directly. The
     * methods listed above are all non-privileged calls.
     *
     * @return the GSSContext object
     */
    public GSSContext x() {
        return x;
    }

    /**
     * Disposes the GSSContext within
     * @throws org.ietf.jgss.GSSException
     */
    public void dispose() throws GSSException {
        x.dispose();
    }

    /**
     * Does something using the Subject inside
     * @param action the action
     * @param in the input byte
     * @return the output byte
     * @throws java.lang.Exception
     */
    public byte[] doAs(final Action action, final byte[] in) throws Exception {
        try {
            return Subject.doAs(s, new PrivilegedExceptionAction<byte[]>() {

                @Override
                public byte[] run() throws Exception {
                    return action.run(Context.this, in);
                }
            });
        } catch (PrivilegedActionException pae) {
            throw pae.getException();
        }
    }

    /**
     * Prints status of GSSContext and Subject
     * @throws java.lang.Exception
     */
    public void status() throws Exception {
        System.out.println("STATUS OF " + name.toUpperCase());
        try {
            StringBuffer sb = new StringBuffer();
            if (x.getAnonymityState()) {
                sb.append("anon, ");
            }
            if (x.getConfState()) {
                sb.append("conf, ");
            }
            if (x.getCredDelegState()) {
                sb.append("deleg, ");
            }
            if (x.getIntegState()) {
                sb.append("integ, ");
            }
            if (x.getMutualAuthState()) {
                sb.append("mutual, ");
            }
            if (x.getReplayDetState()) {
                sb.append("rep det, ");
            }
            if (x.getSequenceDetState()) {
                sb.append("seq det, ");
            }
            System.out.println("Context status of " + name + ": " + sb.toString());
            System.out.println(x.getSrcName() + " -> " + x.getTargName());
        } catch (Exception e) {
            ;// Don't care
        }
        System.out.println("=====================================");
        for (Object o : s.getPrivateCredentials()) {
            System.out.println("    " + o.getClass());
            if (o instanceof KerberosTicket) {
                KerberosTicket kt = (KerberosTicket) o;
                System.out.println("        " + kt.getServer() + " for " + kt.getClient());
            } else if (o instanceof KerberosKey) {
                KerberosKey kk = (KerberosKey) o;
                System.out.print("        " + kk.getKeyType() + " " + kk.getVersionNumber() + " " + kk.getAlgorithm() + " ");
                for (byte b : kk.getEncoded()) {
                    System.out.printf("%02X", b & 0xff);
                }
                System.out.println();
            } else if (o instanceof Map) {
                Map map = (Map) o;
                for (Object k : map.keySet()) {
                    System.out.println("        " + k + ": " + map.get(k));
                }
            }
        }
    }

    /**
     * Transmits a message from one Context to another. The sender wraps the
     * message and sends it to the receiver. The receiver unwraps it, creates
     * a MIC of the clear text and sends it back to the sender. The sender
     * verifies the MIC against the message sent earlier.
     * @param message the message
     * @param s1 the sender
     * @param s2 the receiver
     * @throws java.lang.Exception If anything goes wrong
     */
    static public void transmit(final String message, final Context s1,
            final Context s2) throws Exception {
        final byte[] messageBytes = message.getBytes();
        System.out.printf("-------------------- TRANSMIT from %s to %s------------------------\n",
                s1.name, s2.name);

        byte[] t = s1.doAs(new Action() {
            @Override
            public byte[] run(Context me, byte[] dummy) throws Exception {
                System.out.println("wrap");
                MessageProp p1 = new MessageProp(0, true);
                byte[] out = me.x.wrap(messageBytes, 0, messageBytes.length, p1);
                System.out.println(printProp(p1));
                return out;
            }
        }, null);

        t = s2.doAs(new Action() {
            @Override
            public byte[] run(Context me, byte[] input) throws Exception {
                MessageProp p1 = new MessageProp(0, true);
                byte[] bytes = me.x.unwrap(input, 0, input.length, p1);
                if (!Arrays.equals(messageBytes, bytes))
                    throw new Exception("wrap/unwrap mismatch");
                System.out.println("unwrap");
                System.out.println(printProp(p1));
                p1 = new MessageProp(0, true);
                System.out.println("getMIC");
                bytes = me.x.getMIC(bytes, 0, bytes.length, p1);
                System.out.println(printProp(p1));
                return bytes;
            }
        }, t);
        // Re-unwrap should make p2.isDuplicateToken() returns true
        s1.doAs(new Action() {
            @Override
            public byte[] run(Context me, byte[] input) throws Exception {
                MessageProp p1 = new MessageProp(0, true);
                System.out.println("verifyMIC");
                me.x.verifyMIC(input, 0, input.length,
                        messageBytes, 0, messageBytes.length,
                        p1);
                System.out.println(printProp(p1));
                return null;
            }
        }, t);
    }

    /**
     * Returns a string description of a MessageProp object
     * @param prop the object
     * @return the description
     */
    static public String printProp(MessageProp prop) {
        StringBuffer sb = new StringBuffer();
        sb.append("MessagePop: ");
        sb.append("QOP="+ prop.getQOP() + ", ");
        sb.append(prop.getPrivacy()?"privacy, ":"");
        sb.append(prop.isDuplicateToken()?"dup, ":"");
        sb.append(prop.isGapToken()?"gap, ":"");
        sb.append(prop.isOldToken()?"old, ":"");
        sb.append(prop.isUnseqToken()?"unseq, ":"");
        sb.append(prop.getMinorString()+ "(" + prop.getMinorStatus()+")");
        return sb.toString();
    }

    /**
     * Handshake (security context establishment process) between two Contexts
     * @param c the initiator
     * @param s the acceptor
     * @throws java.lang.Exception
     */
    static public void handshake(final Context c, final Context s) throws Exception {
        byte[] t = new byte[0];
        while (!c.f || !s.f) {
            t = c.doAs(new Action() {
                @Override
                public byte[] run(Context me, byte[] input) throws Exception {
                    if (me.x.isEstablished()) {
                        me.f = true;
                        System.out.println(c.name + " side established");
                        return null;
                    } else {
                        System.out.println(c.name + " call initSecContext");
                        return me.x.initSecContext(input, 0, input.length);
                    }
                }
            }, t);

            t = s.doAs(new Action() {
                @Override
                public byte[] run(Context me, byte[] input) throws Exception {
                    if (me.x.isEstablished()) {
                        me.f = true;
                        System.out.println(s.name + " side established");
                        return null;
                    } else {
                        System.out.println(s.name + " called acceptSecContext");
                        return me.x.acceptSecContext(input, 0, input.length);
                    }
                }
            }, t);
        }
    }
}