private void CreateAttributeSelector(object sender, EventArgs args)
{
pol.AttributeSelectorElement attr = new pol.AttributeSelectorElement(string.Empty, false, "TODO: Add XPath", XacmlVersion.Version11);
AttributeSelector node = new AttributeSelector(attr);
tvwCondition.Nodes.Add(node);
_condition.Arguments.Add(attr);
}
private void CreateAttributeSelectorFromFunction(object sender, EventArgs args)
{
FunctionExecution func = (FunctionExecution)tvwCondition.SelectedNode;
pol.ApplyBaseReadWrite parentApply = func.ApplyBaseDefinition;
pol.AttributeSelectorElement attr = new pol.AttributeSelectorElement(string.Empty, false, "TODO: Add XPath", XacmlVersion.Version11);
AttributeSelector node = new AttributeSelector(attr);
func.Nodes.Add(node);
parentApply.Arguments.Add(attr);
}
/// <summary>
/// Evaluates the variable into a value.
/// </summary>
/// <param name="context">The contex of the evaluation.</param>
/// <returns>The value of the function.</returns>
public EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
context.Trace("Evaluating variable");
context.AddIndent();
try
{
if (_variableDefinition.Expression is pol.ApplyElement)
{
context.Trace("Apply within condition.");
// There is a nested apply un this policy a new Apply will be created and also
// evaluated. It's return value will be used as the processed argument.
Apply _childApply = new Apply((pol.ApplyElement)_variableDefinition.Expression);
// Evaluate the Apply
_value = _childApply.Evaluate(context);
context.TraceContextValues();
return(_value);
}
else if (_variableDefinition.Expression is pol.FunctionElement)
{
throw new NotImplementedException("FunctionElement"); //TODO:
}
else if (_variableDefinition.Expression is pol.VariableReferenceElement)
{
pol.VariableReferenceElement variableRef = _variableDefinition.Expression as pol.VariableReferenceElement;
VariableDefinition variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition;
context.TraceContextValues();
if (!variableDef.IsEvaluated)
{
return(variableDef.Evaluate(context));
}
else
{
return(variableDef.Value);
}
}
else if (_variableDefinition.Expression is pol.AttributeValueElementReadWrite)
{
// The AttributeValue does not need to be processed
context.Trace("Attribute value {0}", _variableDefinition.Expression.ToString());
pol.AttributeValueElementReadWrite att = (pol.AttributeValueElementReadWrite)_variableDefinition.Expression;
pol.AttributeValueElement attributeValue = new pol.AttributeValueElement(att.DataType, att.Contents, att.SchemaVersion);
_value = new EvaluationValue(
attributeValue.GetTypedValue(attributeValue.GetType(context), 0),
attributeValue.GetType(context));
return(_value);
}
else if (_variableDefinition.Expression is pol.AttributeDesignatorBase)
{
// Resolve the AttributeDesignator using the EvaluationEngine public methods.
context.Trace("Processing attribute designator: {0}", _variableDefinition.Expression.ToString());
pol.AttributeDesignatorBase attrDes = (pol.AttributeDesignatorBase)_variableDefinition.Expression;
BagValue bag = EvaluationEngine.Resolve(context, attrDes);
// If the attribute was not resolved by the EvaluationEngine search the
// attribute in the context document, also using the EvaluationEngine public
// methods.
if (bag.BagSize == 0)
{
if (_variableDefinition.Expression is pol.SubjectAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding subject attribute designator: {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.ResourceAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding resource attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.ActionAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding action attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
else if (_variableDefinition.Expression is pol.EnvironmentAttributeDesignatorElement)
{
ctx.AttributeElement attrib = EvaluationEngine.GetAttribute(context, attrDes);
if (attrib != null)
{
context.Trace("Adding environment attribute designator {0}", attrib.ToString());
bag.Add(attrib);
}
}
}
// If the argument was not found and the attribute must be present this is
// a MissingAttribute situation so set the flag. Otherwise add the attribute
// to the processed arguments.
if (bag.BagSize == 0 && attrDes.MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute(attrDes);
_value = EvaluationValue.Indeterminate;
}
else
{
_value = new EvaluationValue(bag, bag.GetType(context));
}
return(_value);
}
else if (_variableDefinition.Expression is pol.AttributeSelectorElement)
{
// Resolve the XPath query using the EvaluationEngine public methods.
context.Trace("Attribute selector");
try
{
pol.AttributeSelectorElement attributeSelector = (pol.AttributeSelectorElement)_variableDefinition.Expression;
BagValue bag = EvaluationEngine.Resolve(context, attributeSelector);
if (bag.Elements.Count == 0 && attributeSelector.MustBePresent)
{
context.Trace("Attribute is missing");
context.IsMissingAttribute = true;
context.AddMissingAttribute(attributeSelector);
_value = EvaluationValue.Indeterminate;
}
else
{
_value = new EvaluationValue(bag, bag.GetType(context));
}
}
catch (EvaluationException e)
{
context.Trace("ERR: {0}", e.Message);
context.ProcessingError = true;
_value = EvaluationValue.Indeterminate;
}
return(_value);
}
throw new NotSupportedException("internal error");
}
finally
{
_isEvaluated = true;
context.RemoveIndent();
}
}
/// <summary>
///
/// </summary>
/// <param name="attributeSelector"></param>
public AttributeSelector(pol.AttributeSelectorElement attributeSelector)
{
_attributeSelector = attributeSelector;
this.Text = "XPath: " + attributeSelector.RequestContextPath;
}
private void CreateAttributeSelectorFromFunction( object sender, EventArgs args )
{
FunctionExecution func = (FunctionExecution)tvwCondition.SelectedNode;
pol.ApplyBaseReadWrite parentApply = func.ApplyBaseDefinition;
pol.AttributeSelectorElement attr = new pol.AttributeSelectorElement( string.Empty, false, "TODO: Add XPath", XacmlVersion.Version11 );
AttributeSelector node = new AttributeSelector( attr );
func.Nodes.Add( node );
parentApply.Arguments.Add( attr );
}
private void CreateAttributeSelector( object sender, EventArgs args )
{
pol.AttributeSelectorElement attr = new pol.AttributeSelectorElement( string.Empty, false, "TODO: Add XPath", XacmlVersion.Version11 );
AttributeSelector node = new AttributeSelector( attr );
tvwCondition.Nodes.Add( node );
_condition.Arguments.Add( attr );
}
/// <summary>
/// This method overrides the ApplyBase method in order to provide extra validations
/// required in the condition evaluation, for example the final return value should be a
/// boolean value.
/// </summary>
/// <param name="context">The evaluation context instance.</param>
/// <returns>The EvaluationValue with the results of the condition evaluation.</returns>
public override EvaluationValue Evaluate(EvaluationContext context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
context.Trace("Evaluating condition");
context.AddIndent();
try
{
// Iterate through the arguments, the IExpressionType is a mark interface
foreach (inf.IExpression arg in ApplyDefinition.Arguments)
{
if (arg is pol.ApplyElement)
{
context.Trace("Apply within condition.");
// There is a nested apply un this policy a new Apply will be created and also
// evaluated. It's return value will be used as the processed argument.
Apply _childApply = new Apply((pol.ApplyElement)arg);
// Evaluate the Apply
EvaluationValue retVal = _childApply.Evaluate(context);
return(retVal);
}
else if (arg is pol.FunctionElementReadWrite)
{
throw new NotImplementedException("FunctionElement"); //TODO:
}
else if (arg is pol.VariableReferenceElement)
{
pol.VariableReferenceElement variableRef = arg as pol.VariableReferenceElement;
VariableDefinition variableDef = context.CurrentPolicy.VariableDefinition[variableRef.VariableId] as VariableDefinition;
if (!variableDef.IsEvaluated)
{
return(variableDef.Evaluate(context));
}
else
{
return(variableDef.Value);
}
}
else if (arg is pol.AttributeValueElementReadWrite)
{
// The AttributeValue does not need to be processed
context.Trace("Attribute value {0}", arg.ToString());
pol.AttributeValueElement attributeValue = new pol.AttributeValueElement(((pol.AttributeValueElementReadWrite)arg).DataType, ((pol.AttributeValueElementReadWrite)arg).Contents, ((pol.AttributeValueElementReadWrite)arg).SchemaVersion);
return(new EvaluationValue(
attributeValue.GetTypedValue(attributeValue.GetType(context), 0),
attributeValue.GetType(context)));
}
else if (arg is pol.AttributeDesignatorBase)
{
// Returning an empty bag, since the condition is not supposed to work with a bag
context.Trace("Processing attribute designator: {0}", arg.ToString());
pol.AttributeDesignatorBase attrDes = (pol.AttributeDesignatorBase)arg;
BagValue bag = new BagValue(EvaluationEngine.GetDataType(attrDes.DataType));
return(new EvaluationValue(bag, bag.GetType(context)));
}
else if (arg is pol.AttributeSelectorElement)
{
// Returning an empty bag, since the condition is not supposed to work with a bag
context.Trace("Attribute selector");
pol.AttributeSelectorElement attrSel = (pol.AttributeSelectorElement)arg;
BagValue bag = new BagValue(EvaluationEngine.GetDataType(attrSel.DataType));
return(new EvaluationValue(bag, bag.GetType(context)));
}
}
throw new NotSupportedException("internal error");
}
finally
{
context.TraceContextValues();
context.RemoveIndent();
}
}
/// <summary>
///
/// </summary>
/// <param name="attributeSelector"></param>
public AttributeSelector( pol.AttributeSelectorElement attributeSelector )
{
_attributeSelector = attributeSelector;
this.Text = "XPath: " + attributeSelector.RequestContextPath;
}
