jdk/src/share/classes/sun/security/x509/GeneralSubtrees.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/security/x509/GeneralSubtrees.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,525 @@
+/*
+ * Copyright 1997-2003 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package sun.security.x509;
+
+import java.io.*;
+import java.util.*;
+
+import sun.security.util.*;
+
+/**
+ * Represent the GeneralSubtrees ASN.1 object.
+ * <p>
+ * The ASN.1 for this is
+ * <pre>
+ * GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
+ * </pre>
+ * </p>
+ *
+ *
+ * @author Amit Kapoor
+ * @author Hemma Prafullchandra
+ * @author Andreas Sterbenz
+ */
+public class GeneralSubtrees implements Cloneable {
+
+    private final List<GeneralSubtree> trees;
+
+    // Private variables
+    private static final int NAME_DIFF_TYPE = GeneralNameInterface.NAME_DIFF_TYPE;
+    private static final int NAME_MATCH = GeneralNameInterface.NAME_MATCH;
+    private static final int NAME_NARROWS = GeneralNameInterface.NAME_NARROWS;
+    private static final int NAME_WIDENS = GeneralNameInterface.NAME_WIDENS;
+    private static final int NAME_SAME_TYPE = GeneralNameInterface.NAME_SAME_TYPE;
+
+    /**
+     * The default constructor for the class.
+     */
+    public GeneralSubtrees() {
+        trees = new ArrayList<GeneralSubtree>();
+    }
+
+    private GeneralSubtrees(GeneralSubtrees source) {
+        trees = new ArrayList<GeneralSubtree>(source.trees);
+    }
+
+    /**
+     * Create the object from the passed DER encoded form.
+     *
+     * @param val the DER encoded form of the same.
+     */
+    public GeneralSubtrees(DerValue val) throws IOException {
+        this();
+        if (val.tag != DerValue.tag_Sequence) {
+            throw new IOException("Invalid encoding of GeneralSubtrees.");
+        }
+        while (val.data.available() != 0) {
+            DerValue opt = val.data.getDerValue();
+            GeneralSubtree tree = new GeneralSubtree(opt);
+            add(tree);
+        }
+    }
+
+    public GeneralSubtree get(int index) {
+        return trees.get(index);
+    }
+
+    public void remove(int index) {
+        trees.remove(index);
+    }
+
+    public void add(GeneralSubtree tree) {
+        if (tree == null) {
+            throw new NullPointerException();
+        }
+        trees.add(tree);
+    }
+
+    public boolean contains(GeneralSubtree tree) {
+        if (tree == null) {
+            throw new NullPointerException();
+        }
+        return trees.contains(tree);
+    }
+
+    public int size() {
+        return trees.size();
+    }
+
+    public Iterator<GeneralSubtree> iterator() {
+        return trees.iterator();
+    }
+
+    public List<GeneralSubtree> trees() {
+        return trees;
+    }
+
+    public Object clone() {
+        return new GeneralSubtrees(this);
+    }
+
+    /**
+     * Return a printable string of the GeneralSubtree.
+     */
+    public String toString() {
+        String s = "   GeneralSubtrees:\n" + trees.toString() + "\n";
+        return s;
+    }
+
+    /**
+     * Encode the GeneralSubtrees.
+     *
+     * @params out the DerOutputStrean to encode this object to.
+     */
+    public void encode(DerOutputStream out) throws IOException {
+        DerOutputStream seq = new DerOutputStream();
+
+        for (int i = 0, n = size(); i < n; i++) {
+            get(i).encode(seq);
+        }
+        out.write(DerValue.tag_Sequence, seq);
+    }
+
+    /**
+     * Compare two general subtrees by comparing the subtrees
+     * of each.
+     *
+     * @param other GeneralSubtrees to compare to this
+     * @returns true if match
+     */
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof GeneralSubtrees == false) {
+            return false;
+        }
+        GeneralSubtrees other = (GeneralSubtrees)obj;
+        return this.trees.equals(other.trees);
+    }
+
+    public int hashCode() {
+        return trees.hashCode();
+    }
+
+    /**
+     * Return the GeneralNameInterface form of the GeneralName in one of
+     * the GeneralSubtrees.
+     *
+     * @param ndx index of the GeneralSubtree from which to obtain the name
+     */
+    private GeneralNameInterface getGeneralNameInterface(int ndx) {
+        return getGeneralNameInterface(get(ndx));
+    }
+
+    private static GeneralNameInterface getGeneralNameInterface(GeneralSubtree gs) {
+        GeneralName gn = gs.getName();
+        GeneralNameInterface gni = gn.getName();
+        return gni;
+    }
+
+    /**
+     * minimize this GeneralSubtrees by removing all redundant entries.
+     * Internal method used by intersect and reduce.
+     */
+    private void minimize() {
+
+        // Algorithm: compare each entry n to all subsequent entries in
+        // the list: if any subsequent entry matches or widens entry n,
+        // remove entry n. If any subsequent entries narrow entry n, remove
+        // the subsequent entries.
+        for (int i = 0; i < size(); i++) {
+            GeneralNameInterface current = getGeneralNameInterface(i);
+            boolean remove1 = false;
+
+            /* compare current to subsequent elements */
+            for (int j = i + 1; j < size(); j++) {
+                GeneralNameInterface subsequent = getGeneralNameInterface(j);
+                switch (current.constrains(subsequent)) {
+                    case GeneralNameInterface.NAME_DIFF_TYPE:
+                        /* not comparable; different name types; keep checking */
+                        continue;
+                    case GeneralNameInterface.NAME_MATCH:
+                        /* delete one of the duplicates */
+                        remove1 = true;
+                        break;
+                    case GeneralNameInterface.NAME_NARROWS:
+                        /* subsequent narrows current */
+                        /* remove narrower name (subsequent) */
+                        remove(j);
+                        j--; /* continue check with new subsequent */
+                        continue;
+                    case GeneralNameInterface.NAME_WIDENS:
+                        /* subsequent widens current */
+                        /* remove narrower name current */
+                        remove1 = true;
+                        break;
+                    case GeneralNameInterface.NAME_SAME_TYPE:
+                        /* keep both for now; keep checking */
+                        continue;
+                }
+                break;
+            } /* end of this pass of subsequent elements */
+
+            if (remove1) {
+                remove(i);
+                i--; /* check the new i value */
+            }
+
+        }
+    }
+
+    /**
+     * create a subtree containing an instance of the input
+     * name type that widens all other names of that type.
+     *
+     * @params name GeneralNameInterface name
+     * @returns GeneralSubtree containing widest name of that type
+     * @throws RuntimeException on error (should not occur)
+     */
+    private GeneralSubtree createWidestSubtree(GeneralNameInterface name) {
+        try {
+            GeneralName newName;
+            switch (name.getType()) {
+            case GeneralNameInterface.NAME_ANY:
+                // Create new OtherName with same OID as baseName, but
+                // empty value
+                ObjectIdentifier otherOID = ((OtherName)name).getOID();
+                newName = new GeneralName(new OtherName(otherOID, null));
+                break;
+            case GeneralNameInterface.NAME_RFC822:
+                newName = new GeneralName(new RFC822Name(""));
+                break;
+            case GeneralNameInterface.NAME_DNS:
+                newName = new GeneralName(new DNSName(""));
+                break;
+            case GeneralNameInterface.NAME_X400:
+                newName = new GeneralName(new X400Address((byte[])null));
+                break;
+            case GeneralNameInterface.NAME_DIRECTORY:
+                newName = new GeneralName(new X500Name(""));
+                break;
+            case GeneralNameInterface.NAME_EDI:
+                newName = new GeneralName(new EDIPartyName(""));
+                break;
+            case GeneralNameInterface.NAME_URI:
+                newName = new GeneralName(new URIName(""));
+                break;
+            case GeneralNameInterface.NAME_IP:
+                newName = new GeneralName(new IPAddressName((byte[])null));
+                break;
+            case GeneralNameInterface.NAME_OID:
+                newName = new GeneralName
+                    (new OIDName(new ObjectIdentifier((int[])null)));
+                break;
+            default:
+                throw new IOException
+                    ("Unsupported GeneralNameInterface type: " + name.getType());
+            }
+            return new GeneralSubtree(newName, 0, -1);
+        } catch (IOException e) {
+            throw new RuntimeException("Unexpected error: " + e, e);
+        }
+    }
+
+    /**
+     * intersect this GeneralSubtrees with other.  This function
+     * is used in merging permitted NameConstraints.  The operation
+     * is performed as follows:
+     * <ul>
+     * <li>If a name in other narrows all names of the same type in this,
+     *     the result will contain the narrower name and none of the
+     *     names it narrows.
+     * <li>If a name in other widens all names of the same type in this,
+     *     the result will not contain the wider name.
+     * <li>If a name in other does not share the same subtree with any name
+     *     of the same type in this, then the name is added to the list
+     *     of GeneralSubtrees returned.  These names should be added to
+     *     the list of names that are specifically excluded.  The reason
+     *     is that, if the intersection is empty, then no names of that
+     *     type are permitted, and the only way to express this in
+     *     NameConstraints is to include the name in excludedNames.
+     * <li>If a name in this has no name of the same type in other, then
+     *     the result contains the name in this.  No name of a given type
+     *     means the name type is completely permitted.
+     * <li>If a name in other has no name of the same type in this, then
+     *     the result contains the name in other.  This means that
+     *     the name is now constrained in some way, whereas before it was
+     *     completely permitted.
+     * <ul>
+     *
+     * @param other GeneralSubtrees to be intersected with this
+     * @returns GeneralSubtrees to be merged with excluded; these are
+     *          empty-valued name types corresponding to entries that were
+     *          of the same type but did not share the same subtree between
+     *          this and other. Returns null if no such.
+     */
+    public GeneralSubtrees intersect(GeneralSubtrees other) {
+
+        if (other == null) {
+            throw new NullPointerException("other GeneralSubtrees must not be null");
+        }
+
+        GeneralSubtrees newThis = new GeneralSubtrees();
+        GeneralSubtrees newExcluded = null;
+
+        // Step 1: If this is empty, just add everything in other to this and
+        // return no new excluded entries
+        if (size() == 0) {
+            union(other);
+            return null;
+        }
+
+        // Step 2: For ease of checking the subtrees, minimize them by
+        // constructing versions that contain only the widest instance of
+        // each type
+        this.minimize();
+        other.minimize();
+
+        // Step 3: Check each entry in this to see whether we keep it or
+        // remove it, and whether we add anything to newExcluded or newThis.
+        // We keep an entry in this unless it is narrowed by all entries in
+        // other.  We add an entry to newExcluded if there is at least one
+        // entry of the same nameType in other, but this entry does
+        // not share the same subtree with any of the entries in other.
+        // We add an entry from other to newThis if there is no name of the
+        // same type in this.
+        for (int i = 0; i < size(); i++) {
+            GeneralNameInterface thisEntry = getGeneralNameInterface(i);
+            boolean removeThisEntry = false;
+
+            // Step 3a: If the widest name of this type in other narrows
+            // thisEntry, remove thisEntry and add widest other to newThis.
+            // Simultaneously, check for situation where there is a name of
+            // this type in other, but no name in other matches, narrows,
+            // or widens thisEntry.
+            boolean sameType = false;
+            for (int j = 0; j < other.size(); j++) {
+                GeneralSubtree otherEntryGS = other.get(j);
+                GeneralNameInterface otherEntry =
+                    getGeneralNameInterface(otherEntryGS);
+                switch (thisEntry.constrains(otherEntry)) {
+                    case NAME_NARROWS:
+                        remove(i);
+                        i--;
+                        newThis.add(otherEntryGS);
+                        sameType = false;
+                        break;
+                    case NAME_SAME_TYPE:
+                        sameType = true;
+                        continue;
+                    case NAME_MATCH:
+                    case NAME_WIDENS:
+                        sameType = false;
+                        break;
+                    case NAME_DIFF_TYPE:
+                    default:
+                        continue;
+                }
+                break;
+            }
+
+            // Step 3b: If sameType is still true, we have the situation
+            // where there was a name of the same type as thisEntry in
+            // other, but no name in other widened, matched, or narrowed
+            // thisEntry.
+            if (sameType) {
+
+                // Step 3b.1: See if there are any entries in this and other
+                // with this type that match, widen, or narrow each other.
+                // If not, then we need to add a "widest subtree" of this
+                // type to excluded.
+                boolean intersection = false;
+                for (int j = 0; j < size(); j++) {
+                    GeneralNameInterface thisAltEntry = getGeneralNameInterface(j);
+
+                    if (thisAltEntry.getType() == thisEntry.getType()) {
+                        for (int k = 0; k < other.size(); k++) {
+                            GeneralNameInterface othAltEntry =
+                                other.getGeneralNameInterface(k);
+
+                            int constraintType =
+                                thisAltEntry.constrains(othAltEntry);
+                            if (constraintType == NAME_MATCH ||
+                                constraintType == NAME_WIDENS ||
+                                constraintType == NAME_NARROWS) {
+                                intersection = true;
+                                break;
+                            }
+                        }
+                    }
+                }
+                if (intersection == false) {
+                    if (newExcluded == null) {
+                        newExcluded = new GeneralSubtrees();
+                    }
+                    GeneralSubtree widestSubtree =
+                         createWidestSubtree(thisEntry);
+                    if (!newExcluded.contains(widestSubtree)) {
+                        newExcluded.add(widestSubtree);
+                    }
+                }
+
+                // Step 3b.2: Remove thisEntry from this
+                remove(i);
+                i--;
+            }
+        }
+
+        // Step 4: Add all entries in newThis to this
+        if (newThis.size() > 0) {
+            union(newThis);
+        }
+
+        // Step 5: Add all entries in other that do not have any entry of the
+        // same type in this to this
+        for (int i = 0; i < other.size(); i++) {
+            GeneralSubtree otherEntryGS = other.get(i);
+            GeneralNameInterface otherEntry = getGeneralNameInterface(otherEntryGS);
+            boolean diffType = false;
+            for (int j = 0; j < size(); j++) {
+                GeneralNameInterface thisEntry = getGeneralNameInterface(j);
+                switch (thisEntry.constrains(otherEntry)) {
+                    case NAME_DIFF_TYPE:
+                        diffType = true;
+                        // continue to see if we find something later of the
+                        // same type
+                        continue;
+                    case NAME_NARROWS:
+                    case NAME_SAME_TYPE:
+                    case NAME_MATCH:
+                    case NAME_WIDENS:
+                        diffType = false; // we found an entry of the same type
+                        // break because we know we won't be adding it to
+                        // this now
+                        break;
+                    default:
+                        continue;
+                }
+                break;
+            }
+            if (diffType) {
+                add(otherEntryGS);
+            }
+        }
+
+        // Step 6: Return the newExcluded GeneralSubtrees
+        return newExcluded;
+    }
+
+    /**
+     * construct union of this GeneralSubtrees with other.
+     *
+     * @param other GeneralSubtrees to be united with this
+     */
+    public void union(GeneralSubtrees other) {
+        if (other != null) {
+            for (int i = 0, n = other.size(); i < n; i++) {
+                add(other.get(i));
+            }
+            // Minimize this
+            minimize();
+        }
+    }
+
+    /**
+     * reduce this GeneralSubtrees by contents of another.  This function
+     * is used in merging excluded NameConstraints with permitted NameConstraints
+     * to obtain a minimal form of permitted NameConstraints.  It is an
+     * optimization, and does not affect correctness of the results.
+     *
+     * @param excluded GeneralSubtrees
+     */
+    public void reduce(GeneralSubtrees excluded) {
+        if (excluded == null) {
+            return;
+        }
+        for (int i = 0, n = excluded.size(); i < n; i++) {
+            GeneralNameInterface excludedName = excluded.getGeneralNameInterface(i);
+            for (int j = 0; j < size(); j++) {
+                GeneralNameInterface permitted = getGeneralNameInterface(j);
+                switch (excludedName.constrains(permitted)) {
+                case GeneralNameInterface.NAME_DIFF_TYPE:
+                    break;
+                case GeneralNameInterface.NAME_MATCH:
+                    remove(j);
+                    j--;
+                    break;
+                case GeneralNameInterface.NAME_NARROWS:
+                    /* permitted narrows excluded */
+                    remove(j);
+                    j--;
+                    break;
+                case GeneralNameInterface.NAME_WIDENS:
+                    /* permitted widens excluded */
+                    break;
+                case GeneralNameInterface.NAME_SAME_TYPE:
+                    break;
+                }
+            } /* end of this pass of permitted */
+        } /* end of pass of excluded */
+    }
+}