RegexPolicyProvider.java
/*
* Copyright 2021 Red Hat, Inc. and/or its affiliates
* and other 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.keycloak.authorization.policy.provider.regex;
import static org.keycloak.utils.JsonUtils.getJsonValue;
import static org.keycloak.utils.JsonUtils.hasPath;
import static org.keycloak.utils.JsonUtils.splitClaimPath;
import java.io.IOException;
import java.util.List;
import java.util.Optional;
import java.util.function.BiFunction;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.keycloak.authorization.AuthorizationProvider;
import org.keycloak.authorization.attribute.Attributes;
import org.keycloak.authorization.model.Policy;
import org.keycloak.authorization.policy.evaluation.Evaluation;
import org.keycloak.authorization.policy.provider.PolicyProvider;
import org.keycloak.representations.idm.authorization.RegexPolicyRepresentation;
import org.keycloak.util.JsonSerialization;
import com.fasterxml.jackson.databind.JsonNode;
/**
* @author <a href="mailto:yoshiyuki.tabata.jy@hitachi.com">Yoshiyuki Tabata</a>
*/
public class RegexPolicyProvider implements PolicyProvider {
private final BiFunction<Policy, AuthorizationProvider, RegexPolicyRepresentation> representationFunction;
public RegexPolicyProvider(BiFunction<Policy, AuthorizationProvider, RegexPolicyRepresentation> representationFunction) {
this.representationFunction = representationFunction;
}
@Override
public void close() {
}
@Override
public void evaluate(Evaluation evaluation) {
AuthorizationProvider authorizationProvider = evaluation.getAuthorizationProvider();
RegexPolicyRepresentation policy = representationFunction.apply(evaluation.getPolicy(), authorizationProvider);
String value = getClaimValue(evaluation, policy);
if (value == null) {
return;
}
Pattern pattern = Pattern.compile(policy.getPattern());
Matcher matcher = pattern.matcher(value);
if (matcher.matches()) {
evaluation.grant();
}
}
private String getClaimValue(Evaluation evaluation, RegexPolicyRepresentation policy) {
Attributes attributes = evaluation.getContext().getIdentity().getAttributes();
String targetClaim = policy.getTargetClaim();
try {
if (hasPath(targetClaim)) {
return resolveJsonValue(attributes, targetClaim);
}
return resolveSimpleValue(attributes, targetClaim);
} catch (IOException cause) {
throw new RuntimeException("Failed to resolve value from claim: " + targetClaim, cause);
}
}
private String resolveSimpleValue(Attributes attributes, String targetClaim) {
Attributes.Entry value = attributes.getValue(targetClaim);
if (value == null || value.isEmpty()) {
return null;
}
return value.asString(0);
}
private String resolveJsonValue(Attributes attributes, String targetClaim) throws IOException {
List<String> paths = splitClaimPath(targetClaim);
if (paths.isEmpty()) {
return null;
}
Attributes.Entry attribute = attributes.getValue(paths.get(0));
if (attribute == null || attribute.isEmpty()) {
return null;
}
JsonNode node = JsonSerialization.readValue(attribute.asString(0), JsonNode.class);
String path = String.join(".", paths.subList(1, paths.size()));
return Optional.ofNullable(getJsonValue(node, path)).map(Object::toString).orElse(null);
}
}