JDK8/Java8源码在线阅读
/*
* Copyright (c) 1997, 2003, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
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);
}
}
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