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comparison src/org/dancres/blitz/remote/ProxyVerifier.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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1 package org.dancres.blitz.remote;
2
3 import java.io.Serializable;
4 import java.io.IOException;
5 import java.io.InvalidObjectException;
6 import java.io.ObjectInputStream;
7
8 import java.rmi.RemoteException;
9
10 import net.jini.security.TrustVerifier;
11
12 import net.jini.security.proxytrust.TrustEquivalence;
13
14 import net.jini.core.constraint.RemoteMethodControl;
15 import net.jini.core.constraint.MethodConstraints;
16
17 import net.jini.id.Uuid;
18
19 /**
20 This class is responsible for verifying any of Blitz's proxy implementations
21 including LeaseImpl, BlitzProxy, AdminProxy and TxnParticipantProxy
22 */
23 class ProxyVerifier implements TrustVerifier, Serializable {
24 private RemoteMethodControl theOriginalStub;
25 private Uuid theOriginalUuid;
26
27 /**
28 Ensures that the passed stub meets the necessary criteria for
29 TrustVerification. If the stub does not qualify, we throw an
30 UnsupportedOperationException. This set of tests is necessary due
31 to the fact that the stub's compliance is determind, in part by
32 configuration of the appropriate Exporter in the config file.
33 */
34 ProxyVerifier(BlitzServer aServer, Uuid aUuid) {
35 if (! (aServer instanceof RemoteMethodControl))
36 throw new UnsupportedOperationException("Server stub does not support RemoteMethodControl - wrong Exporter?");
37
38 if (! (aServer instanceof TrustEquivalence))
39 throw new UnsupportedOperationException("Server stub does not support TrustEquivalance - wrong Exporter?");
40
41 theOriginalStub = (RemoteMethodControl) aServer;
42 theOriginalUuid = aUuid;
43 }
44
45 public boolean isTrustedObject(Object anObject,
46 TrustVerifier.Context aContext)
47 throws RemoteException {
48
49 RemoteMethodControl myOtherServer;
50 Uuid myOtherUuid;
51
52 /*
53 One might be tempted to implement all of this by having all proxies
54 implement a particular interface and obtain the details like that
55 but it opens the way to a "foreign" proxy implementing the interface
56 and nothing else such that it passes all our tests but actually isn't
57 our proxy - thus we test the concrete class.
58 */
59 if (anObject instanceof ConstrainableBlitzProxy) {
60 ConstrainableBlitzProxy myProxy = (ConstrainableBlitzProxy)
61 anObject;
62
63 myOtherServer = (RemoteMethodControl) myProxy.theStub;
64 myOtherUuid = myProxy.theUuid;
65 } else if (anObject instanceof ConstrainableTxnParticipantProxy) {
66 ConstrainableTxnParticipantProxy myProxy =
67 (ConstrainableTxnParticipantProxy) anObject;
68
69 myOtherServer = (RemoteMethodControl) myProxy.theStub;
70 myOtherUuid = myProxy.theUuid;
71 } else if (anObject instanceof ConstrainableAdminProxy) {
72 ConstrainableAdminProxy myProxy =
73 (ConstrainableAdminProxy) anObject;
74
75 myOtherServer = (RemoteMethodControl) myProxy.theStub;
76 myOtherUuid = myProxy.theUuid;
77 } else if (anObject instanceof ConstrainableLeaseImpl) {
78 ConstrainableLeaseImpl myProxy =
79 (ConstrainableLeaseImpl) anObject;
80
81 myOtherServer = (RemoteMethodControl) myProxy.theStub;
82 myOtherUuid = myProxy.theUuid;
83 } else if ((anObject instanceof BlitzServer) &&
84 (anObject instanceof RemoteMethodControl)) {
85 // Contributed services have this their code - might this be due
86 // to Activation?
87 myOtherServer = (RemoteMethodControl) anObject;
88 myOtherUuid = theOriginalUuid;
89 } else {
90 // It's nothing we know about - fail it.
91 return false;
92 }
93
94 if (! theOriginalUuid.equals(myOtherUuid))
95 return false;
96
97 // Get client constraints from passed proxy
98 MethodConstraints myConstraints = myOtherServer.getConstraints();
99
100 // Create copy of original server stub with constraints applied
101 TrustEquivalence myConstrainedStub =
102 (TrustEquivalence) theOriginalStub.setConstraints(myConstraints);
103
104 return myConstrainedStub.checkTrustEquivalence(myOtherServer);
105 }
106
107 /**
108 We override this method to check that integrity of the Verifier has
109 been maintained. There are a number of potential sources of compromise
110 such as "fiddling" with the serialized steam or a "misbehaving" JVM
111 implementation.
112 */
113 private void readObject(ObjectInputStream anOIS)
114 throws IOException, ClassNotFoundException {
115
116 anOIS.defaultReadObject();
117
118 if ((theOriginalStub == null) || (theOriginalUuid == null)) {
119 throw new InvalidObjectException("Internal state has been compromised");
120 }
121
122 if (! (theOriginalStub instanceof TrustEquivalence))
123 throw new InvalidObjectException("Stub doesn't implement TrustEquivalence");
124 }
125 }
126
127