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/*
*
* Copyright (c) 2013,2019 AT&T Knowledge Ventures
* SPDX-License-Identifier: MIT
*/
package com.att.research.xacmlatt.pdp.std.functions;
import java.util.ArrayList;
import java.util.List;
import com.att.research.xacml.api.AttributeValue;
import com.att.research.xacml.api.DataType;
import com.att.research.xacml.api.Identifier;
import com.att.research.xacml.std.StdStatus;
import com.att.research.xacml.std.StdStatusCode;
import com.att.research.xacmlatt.pdp.eval.EvaluationContext;
import com.att.research.xacmlatt.pdp.policy.Bag;
import com.att.research.xacmlatt.pdp.policy.ExpressionResult;
import com.att.research.xacmlatt.pdp.policy.FunctionArgument;
/**
* FunctionDefinitionSet implements {@link com.att.research.xacmlatt.pdp.policy.FunctionDefinition} to
* implement the XACML Set predicates as functions taking two arguments of Bag the same primitive type
* and returning either a Boolean or a Bag of the same primitive type.
*
* The ipAddress, dnsName and xPathExpression do not have set functions defined for them in section 10.2.8 of the Release 3 XACML spec.
*
* In the first implementation of XACML we had separate files for each XACML Function.
* This release combines multiple Functions in fewer files to minimize code duplication.
* This file supports the following XACML codes:
* string-bag
* boolean-bag
* integer-bag
* double-bag
* time-bag
* date-bag
* dateTime-bag
* anyURI-bag
* hexBinary-bag
* base64Binary-bag
* dayTimeDuration-bag (version 1 and3)
* yearMonthDuration-bag (version 1 and 3)
* x500Name-bag
* rfc822Name-bag
*
*
* @author glenngriffin
* @version $Revision: 1.1 $
*
* @param the java class for the data type of the function Input arguments
* @param the java class for the data type of the function Output
*/
public class FunctionDefinitionSet extends FunctionDefinitionBase {
/**
* List of comparison operations.
*
* @author glenngriffin
*
*/
public enum OPERATION {INTERSECTION, AT_LEAST_ONE_MEMBER_OF, UNION, SUBSET, SET_EQUALS };
// the operation for this instance of the class
private OPERATION operation;
/**
* Constructor - need dataType input because of java Generic type-erasure during compilation.
*
* @param idIn
* @param dataTypeIn
* @param dataTypeArgsIn
* @param opIn
*/
public FunctionDefinitionSet(Identifier idIn, DataType dataTypeIn, DataType dataTypeArgsIn, OPERATION opIn) {
super(idIn, dataTypeIn, dataTypeArgsIn, ((opIn == OPERATION.INTERSECTION || opIn == OPERATION.UNION) ? true : false) );
operation = opIn;
}
@Override
public ExpressionResult evaluate(EvaluationContext evaluationContext, List arguments) {
if (arguments == null || arguments.size() != 2) {
return ExpressionResult.newError(new StdStatus(StdStatusCode.STATUS_CODE_PROCESSING_ERROR, this.getShortFunctionId() + " Expected 2 arguments, got " +
((arguments == null) ? "null" : arguments.size()) ));
}
// get first bag
FunctionArgument bagArgument = arguments.get(0);
ConvertedArgument convertedBagArgument = new ConvertedArgument(bagArgument, null, true);
if ( ! convertedBagArgument.isOk()) {
return ExpressionResult.newError(getFunctionStatus(convertedBagArgument.getStatus()));
}
Bag bag1 = convertedBagArgument.getBag();
List> list1 = (List>) bag1.getAttributeValueList();
// get second bag
bagArgument = arguments.get(1);
convertedBagArgument = new ConvertedArgument(bagArgument, null, true);
if ( ! convertedBagArgument.isOk()) {
return ExpressionResult.newError(getFunctionStatus(convertedBagArgument.getStatus()));
}
Bag bag2 = convertedBagArgument.getBag();
List> list2 = (List>) bag2.getAttributeValueList();
// arguments are ready BUT they have NOT had duplicates removed
ExpressionResult expressionResult = null;
// some functions return a bag rather than boolean
Bag outBag;
List> outList;
switch (operation) {
case INTERSECTION:
outList = new ArrayList>();
for (AttributeValue element : list1) {
if (outList.contains(element)) {
continue;
}
if (list2.contains(element)) {
outList.add(element);
}
}
// now have the intersection; put it in a bag
outBag = new Bag();
for (AttributeValue element : outList) {
outBag.add(element);
}
expressionResult = ExpressionResult.newBag(outBag);
return expressionResult;
case AT_LEAST_ONE_MEMBER_OF:
// look for elements from the first list in the second.
// duplicates do not matter because if the element is not there it does not matter that we look for it again,
// and if it is there we stop the first time we see it.
// If the first bag is empty, this should fail because no element from the first set can be found in the second set
// (because there IS no element in first set).
for (AttributeValue element : list1) {
if (list2.contains(element)) {
return ER_TRUE;
}
}
// did not find any element from list 1 in list 2
return ER_FALSE;
case UNION:
outList = new ArrayList>();
for (AttributeValue element : list1) {
if (outList.contains(element)) {
continue;
}
outList.add((AttributeValue) element);
}
for (AttributeValue element : list2) {
if (outList.contains(element)) {
continue;
}
outList.add((AttributeValue) element);
}
// now have the intersection; put it in a bag
outBag = new Bag();
for (AttributeValue element : outList) {
outBag.add(element);
}
expressionResult = ExpressionResult.newBag(outBag);
return expressionResult;
case SUBSET:
// all elements from list 1 must exist in list 2.
// duplicates do not matter because if an element is not found the first time we stop immediately,
// and if it is found the first time it will also be found for the duplicate.
// If the first set is empty we return TRUE because all elements (i.e. none) in the first set are in the second.
for (AttributeValue element : list1) {
if ( ! list2.contains(element)) {
return ER_FALSE;
}
}
// all elements in list1 were found
return ER_TRUE;
case SET_EQUALS:
// we cannot do a direct one-to-one compare because the lists may contain duplicates. Also they may not be ordered the same.
// So we ask:
// are all elements in list 1 in list 2 (ignoring duplicates)
// are all elements in list 2 in list 1 (ignoring duplicates)
for (AttributeValue element : list1) {
if ( ! list2.contains(element)) {
return ER_FALSE;
}
}
for (AttributeValue element : list2) {
if ( ! list1.contains(element)) {
return ER_FALSE;
}
}
// all elements in each are part of the other
return ER_TRUE;
}
// all cases should have been covered by above - should never get here
return ExpressionResult.newError(new StdStatus(StdStatusCode.STATUS_CODE_PROCESSING_ERROR, this.getShortFunctionId() + " Could not evaluate Set function " + operation));
}
}