org.wildfly.security.keystore.AliasFilter Maven / Gradle / Ivy
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* JBoss, Home of Professional Open Source.
* Copyright 2016 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.wildfly.security.keystore;
import static org.wildfly.common.Assert.checkNotNullParam;
import static org.wildfly.security.keystore.ElytronMessages.log;
import java.security.KeyStore;
import java.util.function.Function;
import java.util.function.Predicate;
import org.wildfly.common.iteration.CodePointIterator;
/**
* A utility to create the {@link Predicate} as used for filtering the aliases in a {@link KeyStore}.
*
* @author Darran Lofthouse
*/
public abstract class AliasFilter implements Predicate {
protected final Predicate previous;
private AliasFilter(Predicate previous) {
this.previous = previous;
}
public static final AliasFilter ALL = new AliasFilter(null) {
@Override
public boolean test(String t) {
return true;
}
};
public static final AliasFilter NONE = new AliasFilter(null) {
@Override
public boolean test(String t) {
return false;
}
};
public AliasFilter add(final String alias) {
return new AliasFilter(this) {
@Override
public boolean test(String t) {
if (alias.equals(t)) {
return true;
} else {
return previous.test(t);
}
}
};
}
public AliasFilter remove(final String alias) {
return new AliasFilter(this) {
@Override
public boolean test(String t) {
if (alias.equals(t)) {
return false;
} else {
return previous.test(t);
}
}
};
} public abstract boolean test(String t);
/**
* Create an AliasFilter based on a filterString in one of the following formats: -
*
*
* - alias1,alais2,alias3 - Only the aliases listed are accepted
* - ALL:-alias1:-alias2:-alias3 - All aliases allowed except those listed.
* - NONE:+alias1:+alias2:+alais3 - Only the aliases listed are accepted
*
*
* Note: For ambiguous definitions aliases are evaluated against the filter string from right to left with the first match winning, e.g.
*
*
* - ALL:-alias1:+alias1 - alias1 is an accepted alias.
*
* @param filterString
* @return
*/
public static AliasFilter fromString(final String filterString) {
CodePointIterator i = CodePointIterator.ofString(checkNotNullParam("filterString", filterString));
if (i.hasNext()) {
String firstWord = i.delimitedBy(',',':').drainToString();
if (i.hasNext()) {
AliasFilter current;
switch (i.next()) {
case ',':
current = NONE.add(firstWord);
while (i.hasNext()) {
current = current.add(i.delimitedBy(',').drainToString());
if (i.hasNext()) i.next(); // Remove the delimiter.
}
break;
case ':':
switch (firstWord) {
case "ALL":
current = ALL;
break;
case "NONE":
current = NONE;
break;
default:
throw log.invalidFirstWord(firstWord);
}
while (i.hasNext()) {
Function function;
switch (i.next()) {
case '+':
function = current::add;
break;
case '-':
function = current::remove;
break;
default:
throw log.missingPlusMinusAt(i.getIndex());
}
if (i.hasNext()) {
current = function.apply(i.delimitedBy(':').drainToString());
if (i.hasNext()) i.next(); // Remove the delimiter.
}
}
break;
default:
throw new IllegalStateException();
}
return current;
} else {
// Only a single 'alias' encountered.
switch (firstWord) {
case "ALL":
return ALL;
case "NONE":
return NONE;
default:
return NONE.add(firstWord);
}
}
} else {
throw log.emptyFilter();
}
}
}