org.wildfly.security.auth.server.NameRewriter Maven / Gradle / Ivy
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* Copyright 2013 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.auth.server;
import java.security.Principal;
import java.util.function.UnaryOperator;
import org.wildfly.common.Assert;
import org.wildfly.security.auth.principal.NamePrincipal;
/**
* A name rewriter. Name rewriters transform names from one form to another for various purposes, including (but
* not limited to):
*
* - Normalizing case
* - Trimming extra whitespace
* - Mapping one naming scheme to another (e.g. "user@realm" to/from "realm/user" or similar)
* - Removing a realm component (e.g. "user@realm" to "user")
*
* A name rewriter may also be used to perform a validation step on the syntax of the name. If the rewriter returns
* {@code null}, the name is not valid according to the rules of the rewriter.
*
* @author David M. Lloyd
*/
@FunctionalInterface
public interface NameRewriter {
/**
* The simple identity name rewriter, which does no rewriting.
*/
NameRewriter IDENTITY_REWRITER = original -> original;
/**
* Rewrite a name. Must not return {@code null}.
*
* @param original the original name (must not be {@code null})
* @return the rewritten name, or {@code null} if the name is invalid
*/
String rewriteName(String original);
/**
* Get this name rewriter as a principal rewriter that applies only to {@link NamePrincipal} instances.
*
* @return the principal rewriter (not {@code null})
*/
default UnaryOperator asPrincipalRewriter() {
return principal -> {
if (principal == null) return null;
if (principal instanceof NamePrincipal) {
String rewritten = NameRewriter.this.rewriteName(principal.getName());
return rewritten == null ? null : new NamePrincipal(rewritten);
}
return principal;
};
}
/**
* Create a name rewriter which chains the given name rewriters; the name will be rewritten through the given rewriters
* in order and then returned. If any rewriter returns {@code null}, then {@code null} is returned.
*
* @param rewriter1 the first name rewriter (must not be {@code null})
* @param rewriter2 the second name rewriter (must not be {@code null})
* @return the name rewriter (not {@code null})
*/
static NameRewriter chain(NameRewriter rewriter1, NameRewriter rewriter2) {
Assert.checkNotNullParam("rewriter1", rewriter1);
Assert.checkNotNullParam("rewriter2", rewriter2);
return n -> {
if (n != null) n = rewriter1.rewriteName(n);
if (n != null) n = rewriter2.rewriteName(n);
return n;
};
}
/**
* Create a name rewriter which chains the given name rewriters; the name will be rewritten through the given rewriters
* in order and then returned. If any rewriter returns {@code null}, then {@code null} is returned.
*
* @param nameRewriters the name rewriters (must not be {@code null}, cannot have {@code null} elements)
* @return the name rewriter (not {@code null})
*/
static NameRewriter chain(NameRewriter... nameRewriters) {
Assert.checkNotNullParam("nameRewriters", nameRewriters);
final NameRewriter[] clone = nameRewriters.clone();
for (int i = 0; i < clone.length; i++) {
Assert.checkNotNullArrayParam("nameRewriters", i, clone[i]);
}
return n -> {
for (NameRewriter r : clone) {
if (n == null) return null;
n = r.rewriteName(n);
}
return n;
};
}
/**
* Create a name rewriter which aggregates the given name rewriters; the first rewriter which successfully rewrites
* the name is used. If all the rewriters return {@code null}, then {@code null} is returned.
*
* @param rewriter1 the first name rewriter (must not be {@code null})
* @param rewriter2 the second name rewriter (must not be {@code null})
* @return the name rewriter (not {@code null})
*/
static NameRewriter aggregate(NameRewriter rewriter1, NameRewriter rewriter2) {
Assert.checkNotNullParam("rewriter1", rewriter1);
Assert.checkNotNullParam("rewriter2", rewriter2);
return n -> {
String rn = rewriter1.rewriteName(n);
if (rn == null) rn = rewriter2.rewriteName(n);
return rn;
};
}
/**
* Create a name rewriter which aggregates the given name rewriters; the first rewriter which successfully rewrites
* the name is used. If all the rewriters return {@code null}, then {@code null} is returned.
*
* @param nameRewriters the name rewriters (must not be {@code null}, cannot have {@code null} elements)
* @return the name rewriter (not {@code null})
*/
static NameRewriter aggregate(NameRewriter... nameRewriters) {
Assert.checkNotNullParam("nameRewriters", nameRewriters);
final NameRewriter[] clone = nameRewriters.clone();
for (int i = 0; i < clone.length; i++) {
Assert.checkNotNullArrayParam("nameRewriters", i, clone[i]);
}
return n -> {
if (n == null) return null;
String rn;
for (NameRewriter r : clone) {
rn = r.rewriteName(n);
if (rn != null) {
return rn;
}
}
return null;
};
}
/**
* Create a name rewriter which always returns the same name.
*
* @param name the name to return
* @return the name
*/
static NameRewriter constant(String name) {
return original -> name;
}
}