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codeql/javascript/ql/lib/semmle/javascript/Collections.qll
Erik Krogh Kristensen d17879e1f9 run the non-us patch
2021-12-20 16:24:41 +01:00

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/**
* Provides predicates and classes for working with the standard library collection implementations.
* Currently [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) and
* [Set](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) are implemented.
*/
import javascript
private import semmle.javascript.dataflow.internal.StepSummary
private import semmle.javascript.dataflow.internal.PreCallGraphStep
private import DataFlow::PseudoProperties
/**
* DEPRECATED. Exists only to support other deprecated elements.
*
* Type-tracking now automatically determines the set of pseudo-properties to include
* ased on which properties are contributed by `SharedTaintStep`s.
*/
deprecated private class PseudoProperty extends string {
PseudoProperty() {
this = [arrayLikeElement(), "1"] or // the "1" is required for the `ForOfStep`.
this =
[
mapValue(any(DataFlow::CallNode c | c.getCalleeName() = "set").getArgument(0)),
mapValueAll()
]
}
}
/**
* DEPRECATED. Use `SharedFlowStep` or `SharedTaintTrackingStep` instead.
*/
abstract deprecated class CollectionFlowStep extends DataFlow::AdditionalFlowStep {
final override predicate step(DataFlow::Node pred, DataFlow::Node succ) { none() }
final override predicate step(
DataFlow::Node p, DataFlow::Node s, DataFlow::FlowLabel pl, DataFlow::FlowLabel sl
) {
none()
}
/**
* Holds if the property `prop` of the object `pred` should be loaded into `succ`.
*/
predicate load(DataFlow::Node pred, DataFlow::Node succ, PseudoProperty prop) { none() }
final override predicate loadStep(DataFlow::Node pred, DataFlow::Node succ, string prop) {
this.load(pred, succ, prop)
}
/**
* Holds if `pred` should be stored in the object `succ` under the property `prop`.
*/
predicate store(DataFlow::Node pred, DataFlow::SourceNode succ, PseudoProperty prop) { none() }
final override predicate storeStep(DataFlow::Node pred, DataFlow::SourceNode succ, string prop) {
this.store(pred, succ, prop)
}
/**
* Holds if the property `prop` should be copied from the object `pred` to the object `succ`.
*/
predicate loadStore(DataFlow::Node pred, DataFlow::Node succ, PseudoProperty prop) { none() }
final override predicate loadStoreStep(DataFlow::Node pred, DataFlow::Node succ, string prop) {
this.loadStore(pred, succ, prop, prop)
}
/**
* Holds if the property `loadProp` should be copied from the object `pred` to the property `storeProp` of object `succ`.
*/
predicate loadStore(
DataFlow::Node pred, DataFlow::Node succ, PseudoProperty loadProp, PseudoProperty storeProp
) {
none()
}
final override predicate loadStoreStep(
DataFlow::Node pred, DataFlow::Node succ, string loadProp, string storeProp
) {
this.loadStore(pred, succ, loadProp, storeProp)
}
}
/**
* DEPRECATED. These steps are now included in the default type tracking steps,
* in most cases one can simply use those instead.
*/
deprecated module CollectionsTypeTracking {
/**
* Gets the result from a single step through a collection, from `pred` to `result` summarized by `summary`.
*/
pragma[inline]
DataFlow::SourceNode collectionStep(DataFlow::Node pred, StepSummary summary) {
exists(PseudoProperty field |
summary = LoadStep(field) and
DataFlow::SharedTypeTrackingStep::loadStep(pred, result, field) and
not field = mapValueUnknownKey() // prune unknown reads in type-tracking
or
summary = StoreStep(field) and
DataFlow::SharedTypeTrackingStep::storeStep(pred, result, field)
or
summary = CopyStep(field) and
DataFlow::SharedTypeTrackingStep::loadStoreStep(pred, result, field)
or
exists(PseudoProperty toField | summary = LoadStoreStep(field, toField) |
DataFlow::SharedTypeTrackingStep::loadStoreStep(pred, result, field, toField)
)
)
}
/**
* Gets the result from a single step through a collection, from `pred` with tracker `t2` to `result` with tracker `t`.
*/
pragma[inline]
DataFlow::SourceNode collectionStep(
DataFlow::SourceNode pred, DataFlow::TypeTracker t, DataFlow::TypeTracker t2
) {
exists(DataFlow::Node mid, StepSummary summary | pred.flowsTo(mid) and t = t2.append(summary) |
result = collectionStep(mid, summary)
)
}
}
/**
* A module for data-flow steps related standard library collection implementations.
*/
private module CollectionDataFlow {
/**
* A step for `Set.add()` method, which adds an element to a Set.
*/
private class SetAdd extends PreCallGraphStep {
override predicate storeStep(DataFlow::Node element, DataFlow::SourceNode obj, string prop) {
exists(DataFlow::MethodCallNode call |
call = obj.getAMethodCall("add") and
element = call.getArgument(0) and
prop = setElement()
)
}
}
/**
* A step for the `Set` constructor, which copies any elements from the first argument into the resulting set.
*/
private class SetConstructor extends PreCallGraphStep {
override predicate loadStoreStep(
DataFlow::Node pred, DataFlow::SourceNode succ, string fromProp, string toProp
) {
exists(DataFlow::NewNode invoke |
invoke = DataFlow::globalVarRef("Set").getAnInstantiation() and
pred = invoke.getArgument(0) and
succ = invoke and
fromProp = arrayLikeElement() and
toProp = setElement()
)
}
}
/**
* A step for modeling `for of` iteration on arrays, maps, sets, and iterators.
*
* For sets and iterators the l-value are the elements of the set/iterator.
* For maps the l-value is a tuple containing a key and a value.
*/
private class ForOfStep extends PreCallGraphStep {
override predicate loadStep(DataFlow::Node obj, DataFlow::Node e, string prop) {
exists(ForOfStmt forOf |
obj = forOf.getIterationDomain().flow() and
e = DataFlow::lvalueNode(forOf.getLValue()) and
prop = arrayLikeElement()
)
}
override predicate loadStoreStep(
DataFlow::Node pred, DataFlow::SourceNode succ, string fromProp, string toProp
) {
exists(ForOfStmt forOf |
pred = forOf.getIterationDomain().flow() and
succ = DataFlow::lvalueNode(forOf.getLValue()) and
fromProp = mapValueAll() and
toProp = "1"
)
}
}
/**
* A step for a call to `forEach` on a Set or Map.
*/
private class SetMapForEach extends PreCallGraphStep {
override predicate loadStep(DataFlow::Node obj, DataFlow::Node element, string prop) {
exists(DataFlow::MethodCallNode call |
call.getMethodName() = "forEach" and
obj = call.getReceiver() and
element = call.getCallback(0).getParameter(0) and
prop = [setElement(), mapValueAll()]
)
}
}
/**
* A call to the `get` method on a Map.
* If the key of the call to `get` has a known string value, then only the value corresponding to that key will be retrieved. (The known string value is encoded as part of the pseudo-property)
*/
private class MapGet extends PreCallGraphStep {
override predicate loadStep(DataFlow::Node obj, DataFlow::Node element, string prop) {
exists(DataFlow::MethodCallNode call |
call.getMethodName() = "get" and
obj = call.getReceiver() and
element = call and
// reading the join of known and unknown values
(prop = mapValue(call.getArgument(0)) or prop = mapValueUnknownKey())
)
}
}
/**
* A call to the `set` method on a Map.
*
* If the key of the call to `set` has a known string value,
* then the value will be stored into a pseudo-property corresponding to the known string value.
* Otherwise the value will be stored into a pseudo-property corresponding to values with unknown keys.
* The value will additionally be stored into a pseudo-property corresponding to all values.
*/
class MapSet extends PreCallGraphStep {
override predicate storeStep(DataFlow::Node element, DataFlow::SourceNode obj, string prop) {
exists(DataFlow::MethodCallNode call |
call = obj.getAMethodCall("set") and
element = call.getArgument(1) and
prop = [mapValue(call.getArgument(0)), mapValueAll()]
)
}
}
/**
* A step for a call to `values` on a Map or a Set.
*/
private class MapAndSetValues extends PreCallGraphStep {
override predicate loadStoreStep(
DataFlow::Node pred, DataFlow::SourceNode succ, string fromProp, string toProp
) {
exists(DataFlow::MethodCallNode call |
call.getMethodName() = "values" and
pred = call.getReceiver() and
succ = call and
fromProp = [mapValueAll(), setElement()] and
toProp = iteratorElement()
)
}
}
/**
* A step for a call to `keys` on a Set.
*/
private class SetKeys extends PreCallGraphStep {
override predicate loadStoreStep(
DataFlow::Node pred, DataFlow::SourceNode succ, string fromProp, string toProp
) {
exists(DataFlow::MethodCallNode call |
call.getMethodName() = "keys" and
pred = call.getReceiver() and
succ = call and
fromProp = setElement() and
toProp = iteratorElement()
)
}
}
}