1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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14 * version 2 for more details (a copy is included in the LICENSE file that
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24 */
25
26package java.security.cert;
27
28import java.util.Iterator;
29import java.util.Set;
30
31/**
32 * An immutable valid policy tree node as defined by the PKIX certification
33 * path validation algorithm.
34 *
35 * <p>One of the outputs of the PKIX certification path validation
36 * algorithm is a valid policy tree, which includes the policies that
37 * were determined to be valid, how this determination was reached,
38 * and any policy qualifiers encountered. This tree is of depth
39 * <i>n</i>, where <i>n</i> is the length of the certification
40 * path that has been validated.
41 *
42 * <p>Most applications will not need to examine the valid policy tree.
43 * They can achieve their policy processing goals by setting the
44 * policy-related parameters in {@code PKIXParameters}. However,
45 * the valid policy tree is available for more sophisticated applications,
46 * especially those that process policy qualifiers.
47 *
48 * <p>{@link PKIXCertPathValidatorResult#getPolicyTree()
49 * PKIXCertPathValidatorResult.getPolicyTree} returns the root node of the
50 * valid policy tree. The tree can be traversed using the
51 * {@link #getChildren getChildren} and {@link #getParent getParent} methods.
52 * Data about a particular node can be retrieved using other methods of
53 * {@code PolicyNode}.
54 *
55 * <p><b>Concurrent Access</b>
56 * <p>All {@code PolicyNode} objects must be immutable and
57 * thread-safe. Multiple threads may concurrently invoke the methods defined
58 * in this class on a single {@code PolicyNode} object (or more than one)
59 * with no ill effects. This stipulation applies to all public fields and
60 * methods of this class and any added or overridden by subclasses.
61 *
62 * @since       1.4
63 * @author      Sean Mullan
64 */
65public interface PolicyNode {
66
67    /**
68     * Returns the parent of this node, or {@code null} if this is the
69     * root node.
70     *
71     * @return the parent of this node, or {@code null} if this is the
72     * root node
73     */
74    PolicyNode getParent();
75
76    /**
77     * Returns an iterator over the children of this node. Any attempts to
78     * modify the children of this node through the
79     * {@code Iterator}'s remove method must throw an
80     * {@code UnsupportedOperationException}.
81     *
82     * @return an iterator over the children of this node
83     */
84    Iterator<? extends PolicyNode> getChildren();
85
86    /**
87     * Returns the depth of this node in the valid policy tree.
88     *
89     * @return the depth of this node (0 for the root node, 1 for its
90     * children, and so on)
91     */
92    int getDepth();
93
94    /**
95     * Returns the valid policy represented by this node.
96     *
97     * @return the {@code String} OID of the valid policy
98     * represented by this node. For the root node, this method always returns
99     * the special anyPolicy OID: "2.5.29.32.0".
100     */
101    String getValidPolicy();
102
103    /**
104     * Returns the set of policy qualifiers associated with the
105     * valid policy represented by this node.
106     *
107     * @return an immutable {@code Set} of
108     * {@code PolicyQualifierInfo}s. For the root node, this
109     * is always an empty {@code Set}.
110     */
111    Set<? extends PolicyQualifierInfo> getPolicyQualifiers();
112
113    /**
114     * Returns the set of expected policies that would satisfy this
115     * node's valid policy in the next certificate to be processed.
116     *
117     * @return an immutable {@code Set} of expected policy
118     * {@code String} OIDs. For the root node, this method
119     * always returns a {@code Set} with one element, the
120     * special anyPolicy OID: "2.5.29.32.0".
121     */
122    Set<String> getExpectedPolicies();
123
124    /**
125     * Returns the criticality indicator of the certificate policy extension
126     * in the most recently processed certificate.
127     *
128     * @return {@code true} if extension marked critical,
129     * {@code false} otherwise. For the root node, {@code false}
130     * is always returned.
131     */
132    boolean isCritical();
133}
134