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25 
26 package com.sun.jndi.ldap.sasl;
27 
28 import javax.security.auth.callback.*;
29 import javax.security.sasl.RealmCallback;
30 import javax.security.sasl.RealmChoiceCallback;
31 import java.io.IOException;
32 
33 /**
34  * DefaultCallbackHandler for satisfying NameCallback and
35  * PasswordCallback for an LDAP client.
36  * NameCallback is used for getting the authentication ID and is
37  * gotten from the java.naming.security.principal property.
38  * PasswordCallback is gotten from the java.naming.security.credentials
39  * property and must be of type String, char[] or byte[].
40  * If byte[], it is assumed to have UTF-8 encoding.
41  *
42  * If the caller of getPassword() will be using the password as
43  * a byte array, then it should encode the char[] array returned by
44  * getPassword() into a byte[] using UTF-8.
45  *
46  * @author Rosanna Lee
47  */
48 final class DefaultCallbackHandler implements CallbackHandler {
49     private char[] passwd;
50     private String authenticationID;
51     private String authRealm;
52 
DefaultCallbackHandler(String principal, Object cred, String realm)53     DefaultCallbackHandler(String principal, Object cred, String realm)
54         throws IOException {
55         authenticationID = principal;
56         authRealm = realm;
57         if (cred instanceof String) {
58             passwd = ((String)cred).toCharArray();
59         } else if (cred instanceof char[]) {
60             passwd = ((char[])cred).clone();
61         } else if (cred != null) {
62             // assume UTF-8 encoding
63             String orig = new String((byte[])cred, "UTF8");
64             passwd = orig.toCharArray();
65         }
66     }
67 
handle(Callback[] callbacks)68     public void handle(Callback[] callbacks)
69         throws IOException, UnsupportedCallbackException {
70             for (int i = 0; i < callbacks.length; i++) {
71                 if (callbacks[i] instanceof NameCallback) {
72                     ((NameCallback)callbacks[i]).setName(authenticationID);
73 
74                 } else if (callbacks[i] instanceof PasswordCallback) {
75                     ((PasswordCallback)callbacks[i]).setPassword(passwd);
76 
77                 } else if (callbacks[i] instanceof RealmChoiceCallback) {
78                     /* Deals with a choice of realms */
79                     String[] choices =
80                         ((RealmChoiceCallback)callbacks[i]).getChoices();
81                     int selected = 0;
82 
83                     if (authRealm != null && authRealm.length() > 0) {
84                         selected = -1; // no realm chosen
85                         for (int j = 0; j < choices.length; j++) {
86                             if (choices[j].equals(authRealm)) {
87                                 selected = j;
88                             }
89                         }
90                         if (selected == -1) {
91                             StringBuilder allChoices = new StringBuilder();
92                             for (int j = 0; j <  choices.length; j++) {
93                                 allChoices.append(choices[j]).append(',');
94                             }
95                             throw new IOException("Cannot match " +
96                                 "'java.naming.security.sasl.realm' property value, '" +
97                                 authRealm + "' with choices " + allChoices +
98                                 "in RealmChoiceCallback");
99                         }
100                     }
101 
102                     ((RealmChoiceCallback)callbacks[i]).setSelectedIndex(selected);
103 
104                 } else if (callbacks[i] instanceof RealmCallback) {
105                     /* 1 or 0 realms specified in challenge */
106                     RealmCallback rcb = (RealmCallback) callbacks[i];
107                     if (authRealm != null) {
108                         rcb.setText(authRealm);  // Use what user supplied
109                     } else {
110                         String defaultRealm = rcb.getDefaultText();
111                         if (defaultRealm != null) {
112                             rcb.setText(defaultRealm); // Use what server supplied
113                         } else {
114                             rcb.setText("");  // Specify no realm
115                         }
116                     }
117                 } else {
118                     throw new UnsupportedCallbackException(callbacks[i]);
119                 }
120             }
121     }
122 
clearPassword()123     void clearPassword() {
124         if (passwd != null) {
125             for (int i = 0; i < passwd.length; i++) {
126                 passwd[i] = '\0';
127             }
128             passwd = null;
129         }
130     }
131 
132     @SuppressWarnings("deprecation")
finalize()133     protected void finalize() throws Throwable {
134         clearPassword();
135     }
136 }
137