Merge pull request #17330 from michaelnebel/java/modelgenfieldbased

Java/C#: Field based model generator (Experimental).

Author: michaelnebel

csharp/ql/src/utils/modelgenerator/internal/CaptureModels.qll

@@ -18,17 +18,35 @@ private class ReturnNodeExt extends DataFlow::Node {
     kind = DataFlowImplCommon::getParamReturnPosition(this, _).getKind()
   }
 
-  string getOutput() {
-    kind instanceof DataFlowImplCommon::ValueReturnKind and
+  /**
+   * Gets the kind of the return node.
+   */
+  DataFlowImplCommon::ReturnKindExt getKind() { result = kind }
+}
+
+bindingset[c]
+private signature string printCallableParamSig(Callable c, ParameterPosition p);
+
+private module PrintReturnNodeExt<printCallableParamSig/2 printCallableParam> {
+  string getOutput(ReturnNodeExt node) {
+    node.getKind() instanceof DataFlowImplCommon::ValueReturnKind and
     result = "ReturnValue"
     or
     exists(ParameterPosition pos |
-      pos = kind.(DataFlowImplCommon::ParamUpdateReturnKind).getPosition() and
-      result = paramReturnNodeAsOutput(returnNodeEnclosingCallable(this), pos)
+      pos = node.getKind().(DataFlowImplCommon::ParamUpdateReturnKind).getPosition() and
+      result = printCallableParam(returnNodeEnclosingCallable(node), pos)
     )
   }
 }
 
+string getOutput(ReturnNodeExt node) {
+  result = PrintReturnNodeExt<paramReturnNodeAsOutput/2>::getOutput(node)
+}
+
+string getContentOutput(ReturnNodeExt node) {
+  result = PrintReturnNodeExt<paramReturnNodeAsContentOutput/2>::getOutput(node)
+}
+
 class DataFlowSummaryTargetApi extends SummaryTargetApi {
   DataFlowSummaryTargetApi() { not isUninterestingForDataFlowModels(this) }
 }
@@ -71,7 +89,8 @@ private predicate isRelevantTaintStep(DataFlow::Node node1, DataFlow::Node node2
  * Holds if content `c` is either a field, a synthetic field or language specific
  * content of a relevant type or a container like content.
  */
-private predicate isRelevantContent(DataFlow::ContentSet c) {
+pragma[nomagic]
+private predicate isRelevantContent0(DataFlow::ContentSet c) {
   isRelevantTypeInContent(c) or
   containerContent(c)
 }
@@ -85,6 +104,16 @@ string parameterNodeAsInput(DataFlow::ParameterNode p) {
   result = qualifierString() and p instanceof InstanceParameterNode
 }
 
+/**
+ * Gets the MaD string representation of the parameter `p`
+ * when used in content flow.
+ */
+string parameterNodeAsContentInput(DataFlow::ParameterNode p) {
+  result = parameterContentAccess(p.asParameter())
+  or
+  result = qualifierString() and p instanceof InstanceParameterNode
+}
+
 /**
  * Gets the MaD input string representation of `source`.
  */
@@ -170,7 +199,7 @@ module PropagateFlowConfig implements DataFlow::StateConfigSig {
   ) {
     exists(DataFlow::ContentSet c |
       DataFlowImplCommon::store(node1, c.getAStoreContent(), node2, _, _) and
-      isRelevantContent(c) and
+      isRelevantContent0(c) and
       (
         state1 instanceof TaintRead and state2.(TaintStore).getStep() = 1
         or
@@ -180,7 +209,7 @@ module PropagateFlowConfig implements DataFlow::StateConfigSig {
     or
     exists(DataFlow::ContentSet c |
       DataFlowPrivate::readStep(node1, c, node2) and
-      isRelevantContent(c) and
+      isRelevantContent0(c) and
       state1.(TaintRead).getStep() + 1 = state2.(TaintRead).getStep()
     )
   }
@@ -196,14 +225,17 @@ module PropagateFlowConfig implements DataFlow::StateConfigSig {
 
 module PropagateFlow = TaintTracking::GlobalWithState<PropagateFlowConfig>;
 
+/**
+ * Gets the summary model(s) of `api`, if there is flow from parameters to return value or parameter.
+ */
 string captureThroughFlow0(
   DataFlowSummaryTargetApi api, DataFlow::ParameterNode p, ReturnNodeExt returnNodeExt
 ) {
   exists(string input, string output |
     p.getEnclosingCallable() = api and
     returnNodeExt.(DataFlow::Node).getEnclosingCallable() = api and
     input = parameterNodeAsInput(p) and
-    output = returnNodeExt.getOutput() and
+    output = getOutput(returnNodeExt) and
     input != output and
     result = Printing::asTaintModel(api, input, output)
   )
@@ -219,6 +251,69 @@ string captureThroughFlow(DataFlowSummaryTargetApi api) {
   )
 }
 
+private module PropagateContentFlowConfig implements ContentDataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) {
+    source instanceof DataFlow::ParameterNode and
+    source.getEnclosingCallable() instanceof DataFlowSummaryTargetApi
+  }
+
+  predicate isSink(DataFlow::Node sink) {
+    sink instanceof ReturnNodeExt and
+    sink.getEnclosingCallable() instanceof DataFlowSummaryTargetApi
+  }
+
+  predicate isAdditionalFlowStep = isAdditionalContentFlowStep/2;
+
+  predicate isBarrier(DataFlow::Node n) {
+    exists(Type t | t = n.getType() and not isRelevantType(t))
+  }
+
+  int accessPathLimit() { result = 2 }
+
+  predicate isRelevantContent(DataFlow::ContentSet s) { isRelevantContent0(s) }
+
+  DataFlow::FlowFeature getAFeature() {
+    result instanceof DataFlow::FeatureEqualSourceSinkCallContext
+  }
+}
+
+private module PropagateContentFlow = ContentDataFlow::Global<PropagateContentFlowConfig>;
+
+private string getContent(PropagateContentFlow::AccessPath ap, int i) {
+  exists(ContentSet head, PropagateContentFlow::AccessPath tail |
+    head = ap.getHead() and
+    tail = ap.getTail()
+  |
+    i = 0 and
+    result = "." + printContent(head)
+    or
+    i > 0 and result = getContent(tail, i - 1)
+  )
+}
+
+private string printStoreAccessPath(PropagateContentFlow::AccessPath ap) {
+  result = concat(int i | | getContent(ap, i), "" order by i)
+}
+
+private string printReadAccessPath(PropagateContentFlow::AccessPath ap) {
+  result = concat(int i | | getContent(ap, i), "" order by i desc)
+}
+
+string captureContentFlow(DataFlowSummaryTargetApi api) {
+  exists(
+    DataFlow::ParameterNode p, ReturnNodeExt returnNodeExt, string input, string output,
+    PropagateContentFlow::AccessPath reads, PropagateContentFlow::AccessPath stores,
+    boolean preservesValue
+  |
+    PropagateContentFlow::flow(p, reads, returnNodeExt, stores, preservesValue) and
+    returnNodeExt.getEnclosingCallable() = api and
+    input = parameterNodeAsContentInput(p) + printReadAccessPath(reads) and
+    output = getContentOutput(returnNodeExt) + printStoreAccessPath(stores) and
+    input != output and
+    result = Printing::asModel(api, input, output, preservesValue)
+  )
+}
+
 /**
  * A dataflow configuration used for finding new sources.
  * The sources are the already known existing sources and the sinks are the API return nodes.
@@ -261,7 +356,7 @@ string captureSource(DataFlowSourceTargetApi api) {
     ExternalFlow::sourceNode(source, kind) and
     api = sink.getEnclosingCallable() and
     not irrelevantSourceSinkApi(source.getEnclosingCallable(), api) and
-    result = Printing::asSourceModel(api, sink.getOutput(), kind)
+    result = Printing::asSourceModel(api, getOutput(sink), kind)
   )
 }
 

csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll

@@ -5,11 +5,14 @@
 private import csharp as CS
 private import semmle.code.csharp.commons.Util as Util
 private import semmle.code.csharp.commons.Collections as Collections
+private import semmle.code.csharp.commons.QualifiedName as QualifiedName
 private import semmle.code.csharp.dataflow.internal.DataFlowDispatch
 private import semmle.code.csharp.dataflow.internal.FlowSummaryImpl as FlowSummaryImpl
 private import semmle.code.csharp.frameworks.system.linq.Expressions
 private import semmle.code.csharp.frameworks.System
+private import semmle.code.csharp.dataflow.internal.TaintTrackingPrivate as TaintTrackingPrivate
 import semmle.code.csharp.dataflow.internal.ExternalFlow as ExternalFlow
+import semmle.code.csharp.dataflow.internal.ContentDataFlow as ContentDataFlow
 import semmle.code.csharp.dataflow.internal.DataFlowImplCommon as DataFlowImplCommon
 import semmle.code.csharp.dataflow.internal.DataFlowPrivate as DataFlowPrivate
 import semmle.code.csharp.dataflow.internal.DataFlowDispatch as DataFlowDispatch
@@ -22,6 +25,8 @@ class Type = CS::Type;
 
 class Callable = CS::Callable;
 
+class ContentSet = DataFlow::ContentSet;
+
 /**
  * Holds if any of the parameters of `api` are `System.Func<>`.
  */
@@ -241,20 +246,40 @@ string parameterAccess(CS::Parameter p) {
   else result = "Argument[" + p.getPosition() + "]"
 }
 
+/**
+ * Gets the MaD string representation of the parameter `p`
+ * when used in content flow.
+ */
+string parameterContentAccess(CS::Parameter p) { result = "Argument[" + p.getPosition() + "]" }
+
 class InstanceParameterNode = DataFlowPrivate::InstanceParameterNode;
 
 class ParameterPosition = DataFlowDispatch::ParameterPosition;
 
+private signature string parameterAccessSig(Parameter p);
+
+module ParamReturnNodeAsOutput<parameterAccessSig/1 getParamAccess> {
+  bindingset[c]
+  string paramReturnNodeAsOutput(CS::Callable c, ParameterPosition pos) {
+    result = getParamAccess(c.getParameter(pos.getPosition()))
+    or
+    pos.isThisParameter() and
+    result = qualifierString()
+  }
+}
+
 /**
  * Gets the MaD string representation of return through parameter at position
  * `pos` of callable `c`.
  */
 bindingset[c]
 string paramReturnNodeAsOutput(CS::Callable c, ParameterPosition pos) {
-  result = parameterAccess(c.getParameter(pos.getPosition()))
-  or
-  pos.isThisParameter() and
-  result = qualifierString()
+  result = ParamReturnNodeAsOutput<parameterAccess/1>::paramReturnNodeAsOutput(c, pos)
+}
+
+bindingset[c]
+string paramReturnNodeAsContentOutput(Callable c, ParameterPosition pos) {
+  result = ParamReturnNodeAsOutput<parameterContentAccess/1>::paramReturnNodeAsOutput(c, pos)
 }
 
 /**
@@ -344,3 +369,44 @@ predicate isRelevantSourceKind(string kind) { any() }
  * Holds if the the content `c` is a container.
  */
 predicate containerContent(DataFlow::ContentSet c) { c.isElement() }
+
+/**
+ * Holds if there is a taint step from `node1` to `node2` in content flow.
+ */
+predicate isAdditionalContentFlowStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+  TaintTrackingPrivate::defaultAdditionalTaintStep(nodeFrom, nodeTo, _) and
+  not nodeTo.asExpr() instanceof CS::ElementAccess and
+  not exists(DataFlow::ContentSet c |
+    DataFlowPrivate::readStep(nodeFrom, c, nodeTo) and containerContent(c)
+  )
+}
+
+bindingset[d]
+private string getFullyQualifiedName(Declaration d) {
+  exists(string qualifier, string name |
+    d.hasFullyQualifiedName(qualifier, name) and
+    result = QualifiedName::getQualifiedName(qualifier, name)
+  )
+}
+
+/**
+ * Gets the MaD string representation of the contentset `c`.
+ */
+string printContent(DataFlow::ContentSet c) {
+  exists(CS::Field f, string name | name = getFullyQualifiedName(f) |
+    c.isField(f) and
+    if f.isEffectivelyPublic()
+    then result = "Field[" + name + "]"
+    else result = "SyntheticField[" + name + "]"
+  )
+  or
+  exists(CS::Property p, string name | name = getFullyQualifiedName(p) |
+    c.isProperty(p) and
+    if p.isEffectivelyPublic()
+    then result = "Property[" + name + "]"
+    else result = "SyntheticField[" + name + "]"
+  )
+  or
+  c.isElement() and
+  result = "Element"
+}

csharp/ql/test/utils/modelgenerator/dataflow/CaptureContentSummaryModels.expected

@@ -0,0 +1,2 @@
+unexpectedModel
+expectedModel

csharp/ql/test/utils/modelgenerator/dataflow/CaptureContentSummaryModels.ext.yml

@@ -0,0 +1,12 @@
+extensions:
+  - addsTo:
+      pack: codeql/csharp-all
+      extensible: summaryModel
+    data:
+      - [ "Models", "ManuallyModelled", False, "HasSummary", "(System.Object)", "", "Argument[0]", "ReturnValue", "value", "manual"]
+
+  - addsTo:
+      pack: codeql/csharp-all
+      extensible: neutralModel
+    data:
+      - [ "Models", "ManuallyModelled", "HasNeutralSummary", "(System.Object)", "summary", "manual"]

csharp/ql/test/utils/modelgenerator/dataflow/CaptureContentSummaryModels.ql

@@ -0,0 +1,11 @@
+import csharp
+import utils.modelgenerator.internal.CaptureModels
+import TestUtilities.InlineMadTest
+
+module InlineMadTestConfig implements InlineMadTestConfigSig {
+  string getCapturedModel(Callable c) { result = captureContentFlow(c) }
+
+  string getKind() { result = "contentbased-summary" }
+}
+
+import InlineMadTest<InlineMadTestConfig>