chrisdennis commented on code in PR #251: URL: https://github.com/apache/calcite-avatica/pull/251#discussion_r1930617202
########## core/src/main/java/org/apache/calcite/avatica/util/SecurityUtils.java: ########## @@ -0,0 +1,202 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to you 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.apache.calcite.avatica.util; + +import java.lang.invoke.MethodHandle; +import java.lang.invoke.MethodHandles; +import java.lang.invoke.MethodType; +import java.security.PrivilegedAction; +import java.security.PrivilegedActionException; +import java.security.PrivilegedExceptionAction; +import java.util.concurrent.Callable; +import java.util.concurrent.CompletionException; +import javax.security.auth.Subject; + +/** + * This class is loosely based on SecurityUtils in Jetty 12.0 + * + * <p>Collections of utility methods to deal with the scheduled removal + * of the security classes defined by <a href="https://openjdk.org/jeps/411";>JEP 411</a>.</p> + */ +public class SecurityUtils { + private static final MethodHandle CALL_AS = lookupCallAs(); + private static final MethodHandle CURRENT = lookupCurrent(); + private static final MethodHandle DO_PRIVILEGED = lookupDoPrivileged(); + + private SecurityUtils() { + } + + private static MethodHandle lookupCallAs() { + MethodHandles.Lookup lookup = MethodHandles.lookup(); + try { + try { + // Subject.doAs() is deprecated for removal and replaced by Subject.callAs(). + // Lookup first the new API, since for Java versions where both exist, the + // new API delegates to the old API (for example Java 18, 19 and 20). + // Otherwise (Java 17), lookup the old API. + return lookup.findStatic(Subject.class, "callAs", + MethodType.methodType(Object.class, Subject.class, Callable.class)); + } catch (NoSuchMethodException x) { + try { + // Lookup the old API. + MethodType oldSignature = + MethodType.methodType(Object.class, Subject.class, PrivilegedExceptionAction.class); + MethodHandle doAs = lookup.findStatic(Subject.class, "doAs", oldSignature); + // Convert the Callable used in the new API to the PrivilegedAction used in the old + // API. + MethodType convertSignature = + MethodType.methodType(PrivilegedExceptionAction.class, Callable.class); + MethodHandle converter = + lookup.findStatic(SecurityUtils.class, "callableToPrivilegedExceptionAction", + convertSignature); + return MethodHandles.filterArguments(doAs, 1, converter); + } catch (NoSuchMethodException e) { + throw new AssertionError(e); + } + } + } catch (IllegalAccessException e) { + throw new AssertionError(e); + } + } + + private static MethodHandle lookupDoPrivileged() { + try { + // Use reflection to work with Java versions that have and don't have AccessController. + Class<?> klass = + ClassLoader.getSystemClassLoader().loadClass("java.security.AccessController"); + MethodHandles.Lookup lookup = MethodHandles.lookup(); + return lookup.findStatic(klass, "doPrivileged", + MethodType.methodType(Object.class, PrivilegedAction.class)); + } catch (NoSuchMethodException | IllegalAccessException x) { + // Assume that single methods won't be removed from AcessController + throw new AssertionError(x); + } catch (ClassNotFoundException e) { + return null; Review Comment: The calling code cannot handle `AccessController.getContext()` being missing, but it can handle `AccessController.doPrivileged()` being missing (it falls back to a straight call). I can think of two ways to clarify this (if it's deemed necessary): 1. Clarify the method names: `tryLookupDoPrivileged()` vs `lookupGetContext()` or maybe `lookupGetContextOrFail()`. 2. Return optional from all the lookup methods and move the "failure behavior" to the caller, where it is clearer what is happening, (albeit doing this without losing the failure context/information is a little tricky). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
