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Merge pull request #5 from hvitved/csharp/bad-practices-implementation-hiding

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C#: Update queries in `Bad Practices/Implementation Hiding`
This commit is contained in:
calumgrant
2018-08-03 16:06:34 +01:00
committed by GitHub
parent 282545e393 d05109df76
commit 50892818db
41 changed files with 588 additions and 335 deletions
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1
change-notes/1.18/analysis-csharp.md
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@@ -15,6 +15,7 @@
| **Query** | **Tags** | **Purpose** |
|-----------------------------|-----------|--------------------------------------------------------------------|
| [Exposing internal representation (cs/expose-implementation)] | Different results | The query has been rewritten, based on the equivalent Java query. |
| Local scope variable shadows member (cs/local-shadows-member) | maintainability, readability | Replaces the existing queries [Local variable shadows class member (cs/local-shadows-class-member)](https://help.semmle.com/wiki/display/CSHARP/Local+variable+shadows+class+member), [Local variable shadows struct member (cs/local-shadows-struct-member)](https://help.semmle.com/wiki/display/CSHARP/Local+variable+shadows+struct+member), [Parameter shadows class member (cs/parameter-shadows-class-member)](https://help.semmle.com/wiki/display/CSHARP/Parameter+shadows+class+member), and [Parameter shadows struct member (cs/parameter-shadows-struct-member)](https://help.semmle.com/wiki/display/CSHARP/Parameter+shadows+struct+member). |
## Changes to existing queries

10
csharp/ql/src/Bad Practices/Implementation Hiding/AbstractToConcreteCollection.cs
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@@ -1,10 +0,0 @@
class AbstractToConcreteCollection
{
public static void Main(string[] args)
{
ICollection<String> foo = new List<String>();
foo.Add("hello");
foo.Add("world");
List<String> bar = (List<String>)foo; // BAD
}
}

4
csharp/ql/src/Bad Practices/Implementation Hiding/AbstractToConcreteCollection.qhelp
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@@ -12,8 +12,8 @@ more difficult to change which implementation you are using at a later date.</p>
</recommendation>
<example>
<p>The example shows casting from an ICollection to a List. This should be avoided where possible.</p>
<sample src="AbstractToConcreteCollection.cs" />
<p>The example shows casting from an <code>IEnumerable&lt;string&gt;</code> to a <code>List&lt;string&gt;</code>. This should be avoided where possible.</p>
<sample src="AbstractToConcreteCollectionBad.cs" />
</example>
<references>

29
csharp/ql/src/Bad Practices/Implementation Hiding/AbstractToConcreteCollection.ql
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@@ -1,8 +1,8 @@
/**
* @name Cast from abstract to concrete collection
* @description Finds casts from an abstract collection to a concrete implementation
* type. This makes the code brittle; it is best to program against the
* abstract collection interfaces only.
* @description A cast from an abstract collection to a concrete implementation type
* makes the code brittle; it is best to program against the abstract
* collection interface only.
* @kind problem
* @problem.severity warning
* @precision medium
@@ -13,20 +13,25 @@
* external/cwe/cwe-485
*/
import csharp
import semmle.code.csharp.frameworks.system.Collections
import semmle.code.csharp.frameworks.system.collections.Generic
/** A sub-interface of Collection */
/** A collection interface. */
class CollectionInterface extends Interface {
CollectionInterface() {
exists(string name |
this.getSourceDeclaration().getABaseType*().getName() = name and
( name.matches("ICollection<%>")
or name="ICollection")
exists(Interface i |
i = this.getABaseInterface*() |
i instanceof SystemCollectionsICollectionInterface or
i.getSourceDeclaration() instanceof SystemCollectionsGenericICollectionInterface or
i instanceof SystemCollectionsIEnumerableInterface or
i.getSourceDeclaration() instanceof SystemCollectionsGenericIEnumerableTInterface
)
}
}
from CastExpr e, Class c, CollectionInterface i
where e.getType() = c and
e.getExpr().getType().(RefType).getSourceDeclaration() = i
select e, "Questionable cast from abstract " + i.getName()
+ " to concrete implementation " + c.getName() + "."
where e.getType() = c
and e.getExpr().getType() = i
and c.isImplicitlyConvertibleTo(i)
select e, "Questionable cast from abstract '" + i.getName()
+ "' to concrete implementation '" + c.getName() + "'."

21
csharp/ql/src/Bad Practices/Implementation Hiding/AbstractToConcreteCollectionBad.cs Normal file
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@@ -0,0 +1,21 @@
using System.Collections.Generic;
class Bad
{
public static void Main(string[] args)
{
var names = GetNames();
var list = (List<string>) names;
list.Add("Eve");
}
static IEnumerable<string> GetNames()
{
var ret = new List<string>()
{
"Alice",
"Bob"
};
return ret;
}
}

27
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentation.cs
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@@ -1,27 +0,0 @@
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] get()
{
return rarray;
}
}
class ExposeRepresentation
{
public static void Main(string[] args)
{
Range a = new Range(1, 10);
int[] a_range = a.get();
a_range[0] = 500;
Console.WriteLine("Min: " + a.get()[0] + " Max: " + a.get()[1]);
// prints "Min: 500 Max: 10"
}
}

14
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentation.qhelp
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@@ -19,25 +19,25 @@ fields will not be affected.</p>
</recommendation>
<example>
<p>This example clearly demonstrates the problem with passing references to mutable objects outside a class. In this case
it was possible to modify the values in the array despite the Range class not offering any method to do so.</p>
<sample src="ExposeRepresentation.cs" />
it was possible to modify the values in the array despite the <code>Range</code> class not offering any method to do so.</p>
<sample src="ExposeRepresentationBad.cs" />
</example>
<section title="Fixing With an Immutable Object">
<section title="Fixing with an immutable object">
<p>Here the example has been modified to prevent changes to the private field by using a <code>ReadOnlyCollection</code>
object.</p>
<sample src="ExposeRepresentationFix1.cs" />
<sample src="ExposeRepresentationGood1.cs" />
</section>
<section title="Fixing With Defensive Copying">
<section title="Fixing with defensive copying">
<p>This is an example of the same class but this time it returns a defensive copy of the private field. There is also
a short program showing what happens when an attempt is made to modify the data held by the field.</p>
<sample src="ExposeRepresentationFix2.cs" />
<sample src="ExposeRepresentationGood2.cs" />
</section>
<references>
<li>MSDN, C# Programming Guide, <a href="http://msdn.microsoft.com/en-us/library/vstudio/2z4khca9.aspx">Arrays as Objects</a>.</li>
<li>MSDN, C# Programming Guide, <a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/arrays/arrays-as-objects">Arrays as Objects</a>.</li>
<li>MSDN, <a href="http://msdn.microsoft.com/en-us/library/ms132474.aspx">ReadOnlyCollection&lt;T&gt;</a>.</li>
</references>

100
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentation.ql
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@@ -1,40 +1,82 @@
/**
* @name Exposes internal representation
* @description Finds code that may expose an object's internal representation by
* incorporating reference to mutable object.
* @name Exposing internal representation
* @description An object that accidentally exposes its internal representation may allow the
* object's fields to be modified in ways that the object is not prepared to handle.
* @kind problem
* @problem.severity recommendation
* @precision medium
* @precision high
* @id cs/expose-implementation
* @tags reliability
* external/cwe/cwe-485
*/
import csharp
import semmle.code.csharp.commons.Collections
import DataFlow
/* This code stores a reference to an externally mutable object into the internal
representation of the object.
If instances are accessed by untrusted code, and unchecked changes to the mutable
object would compromise security or other important properties,
you will need to do something different. Storing a copy of the object is better
approach in many situations.
predicate storesCollection(Callable c, Parameter p, Field f) {
f.getDeclaringType() = c.getDeclaringType().getABaseType*().getSourceDeclaration() and
f.getType() instanceof CollectionType and
p = c.getAParameter() and
f.getAnAssignedValue() = p.getAnAccess() and
not c.(Modifiable).isStatic()
}
In this analysis an object is considered mutable if it is an array, a
java.util.Hashtable, or a java.util.Date.
The analysis detects stores to fields of these types where the value is given as a
parameter. */
predicate returnsCollection(Callable c, Field f) {
f.getDeclaringType() = c.getDeclaringType().getABaseType*().getSourceDeclaration() and
f.getType() instanceof CollectionType and
c.canReturn(f.getAnAccess()) and
not c.(Modifiable).isStatic()
}
from Assignment a, Field f, VariableAccess va, RefType t
where a.getLValue() = va and
va.getTarget() = f and
f.getType().(RefType).getSourceDeclaration() = t and
( (va.(MemberAccess).hasQualifier() and
va.(MemberAccess).getQualifier() instanceof ThisAccess)
or not va.(MemberAccess).hasQualifier()) and
a.getRValue().(VariableAccess).getTarget() instanceof Parameter and
( t instanceof ArrayType
//Add mutable types here as necessary. Kept the java types as a reference
/*or t.hasQualifiedName("java.util", "Hashtable")
or t.hasQualifiedName("java.util", "Date")*/)
select a,
"May expose internal representation by storing an externally mutable object in "
+ f.getName() + "."
predicate mayWriteToCollection(Expr modified) {
modified instanceof CollectionModificationAccess
or
exists(Expr mid |
mayWriteToCollection(mid) |
localFlow(exprNode(modified), exprNode(mid))
)
or
exists(MethodCall mid, Callable c |
mayWriteToCollection(mid) |
mid.getTarget() = c and
c.canReturn(modified)
)
}
predicate modificationAfter(Expr before, Expr after) {
mayWriteToCollection(after) and
localFlowStep+(exprNode(before), exprNode(after))
}
VariableAccess varPassedInto(Callable c, Parameter p) {
exists(Call call |
call.getTarget() = c |
call.getArgumentForParameter(p) = result
)
}
predicate exposesByReturn(Callable c, Field f, Expr why, string whyText) {
returnsCollection(c, f) and
exists(MethodCall ma |
ma.getTarget() = c |
mayWriteToCollection(ma) and
why = ma and
whyText = "after this call to " + c.getName()
)
}
predicate exposesByStore(Callable c, Field f, Expr why, string whyText) {
exists(VariableAccess v, Parameter p |
storesCollection(c, p, f) and
v = varPassedInto(c, p) and
modificationAfter(v, why) and
whyText = "through the variable " + v.getTarget().getName()
)
}
from Callable c, Field f, Expr why, string whyText
where exposesByReturn(c, f, why, whyText) or
exposesByStore(c, f, why, whyText)
select c, "'" + c.getName() + "' exposes the internal representation stored in field '" + f.getName() +
"'. The value may be modified $@.",
why.getLocation(), whyText

29
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentationBad.cs Normal file
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@@ -0,0 +1,29 @@
using System;
class Bad
{
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] Get() => rarray;
}
public static void Main(string[] args)
{
var r = new Range(1, 10);
var r_range = r.Get();
r_range[0] = 500;
Console.WriteLine("Min: " + r.Get()[0] + " Max: " + r.Get()[1]);
// prints "Min: 500 Max: 10"
}
}

20
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentationFix1.cs
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@@ -1,20 +0,0 @@
using System.Collections.ObjectModel;
class Range
{
private ReadOnlyCollection<int> rarray = new ReadOnlyCollection<int>(new int[2]);
public Range(int min, int max)
{
if (min <= max)
{
int[] rarray = new int[2];
rarray[0] = min;
rarray[1] = max;
this.rarray = new ReadOnlyCollection<int>(rarray);
}
}
public ReadOnlyCollection<int> get()
{
return rarray;
}
}

27
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentationFix2.cs
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@@ -1,27 +0,0 @@
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] get()
{
return (int[])rarray.Clone();
}
}
class Program
{
public static void Main(string[] args)
{
Range a = new Range(1, 10);
int[] a_range = a.get();
a_range[0] = 500;
Console.WriteLine("Min: " + a.get()[0] + " Max: " + a.get()[1]);
// prints "Min: 1 Max: 10"
}
}

22
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentationGood1.cs Normal file
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@@ -0,0 +1,22 @@
using System.Collections.ObjectModel;
class Good1
{
class Range
{
private ReadOnlyCollection<int> rarray = new ReadOnlyCollection<int>(new int[2]);
public Range(int min, int max)
{
if (min <= max)
{
int[] rarray = new int[2];
rarray[0] = min;
rarray[1] = max;
this.rarray = new ReadOnlyCollection<int>(rarray);
}
}
public ReadOnlyCollection<int> Get() => rarray;
}
}

29
csharp/ql/src/Bad Practices/Implementation Hiding/ExposeRepresentationGood2.cs Normal file
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@@ -0,0 +1,29 @@
using System;
class Good2
{
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] Get() => (int[])rarray.Clone();
}
public static void Main(string[] args)
{
Range a = new Range(1, 10);
int[] a_range = a.Get();
a_range[0] = 500;
Console.WriteLine("Min: " + a.Get()[0] + " Max: " + a.Get()[1]);
// prints "Min: 1 Max: 10"
}
}

8
csharp/ql/src/Bad Practices/Implementation Hiding/StaticArray.cs
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@@ -1,8 +0,0 @@
class StaticArray
{
public static readonly string[] Foo = { "hello", "world" }; // BAD
public static void Main(string[] args)
{
Foo[0] = "goodbye";
}
}

16
csharp/ql/src/Bad Practices/Implementation Hiding/StaticArray.qhelp
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@@ -3,28 +3,28 @@
"qhelp.dtd">
<qhelp>
<overview>
<p>Arrays might be made static readonly in order to prevent their contents being changed.
This is not the case because arrays are mutable. The readonly option prevents the array from being replaced
by a new array but it does not prevent the internal contents of the array from being changed.</p>
<p>Arrays might be made <code>static readonly</code> to prevent their contents from being changed.
This doesn't have the desired effect because arrays are mutable. The <code>readonly</code> modifier prevents the array from being replaced
by a new array but it does not prevent the contents of the array from being changed.</p>
</overview>
<recommendation>
<p>Consider whether the array could be split up into separate constants. If the array cannot be split then you may
wish to use a ReadOnlyCollection instead of an array.</p>
wish to use a <code>ReadOnlyCollection</code> instead of an array.</p>
</recommendation>
<example>
<p>In this example the "Foo" array is readonly but it is still modified by the Main method.</p>
<sample src="StaticArray.cs" />
<p>In this example the <code>Foo</code> array is <code>readonly</code> but it is still modified by the <code>Main</code> method.</p>
<sample src="StaticArrayBad.cs" />
<p>This example uses a <code>ReadOnlyCollection</code>. Any attempt to modify <code>Foo</code> will
cause the program not to compile.</p>
<sample src="StaticArrayFix.cs" />
<sample src="StaticArrayGood.cs" />
</example>
<references>
<li>MSDN, C# Programming Guide, <a href="http://msdn.microsoft.com/en-us/library/vstudio/2z4khca9.aspx">Arrays as Objects</a>.</li>
<li>MSDN, C# Programming Guide, <a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/arrays/arrays-as-objects">Arrays as Objects</a>.</li>
<li>MSDN, <a href="http://msdn.microsoft.com/en-us/library/ms132474.aspx">ReadOnlyCollection&lt;T&gt;</a>.</li>
</references>

32
csharp/ql/src/Bad Practices/Implementation Hiding/StaticArray.ql
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@@ -1,10 +1,9 @@
/**
* @name Static array and non-empty array literal
* @description Finds public constants that are assigned an array.
* Arrays are mutable and can be changed by malicious code or by accident.
* @name Array constant vulnerable to change
* @description Array constants are mutable and can be changed by malicious code or by accident.
* @kind problem
* @problem.severity recommendation
* @precision high
* @precision medium
* @id cs/static-array
* @tags reliability
* maintainability
@@ -14,25 +13,28 @@
import csharp
predicate nonEmptyArrayLiteralOrNull(Expr e) {
exists(ArrayCreation arr | arr = e |
e = any(ArrayCreation arr |
exists(arr.getInitializer().getAnElement())
or
not arr.getALengthArgument().getValue() = "0"
)
or e instanceof NullLiteral
or
exists(ConditionalExpr cond | cond = e |
e instanceof NullLiteral
or
e = any(ConditionalExpr cond |
nonEmptyArrayLiteralOrNull(cond.getThen()) and
nonEmptyArrayLiteralOrNull(cond.getElse())
)
}
from Field f
where f.isPublic() and
f.isStatic() and
f.isReadOnly() and
f.getType() instanceof ArrayType and
f.fromSource() and
forall(AssignExpr a | a.getLValue() = f.getAnAccess() | nonEmptyArrayLiteralOrNull(a.getRValue())) and
forall(Expr e | e = f.getInitializer() | nonEmptyArrayLiteralOrNull(e))
select f, f.getName() + " is a static array vulnerable to mutation."
where f.isPublic()
and f.isStatic()
and f.isReadOnly()
and f.getType() instanceof ArrayType
and f.fromSource()
and forall(AssignableDefinition def |
def.getTarget() = f |
nonEmptyArrayLiteralOrNull(def.getSource())
)
select f, "The array constant '" + f.getName() + "' is vulnerable to mutation."

8
csharp/ql/src/Bad Practices/Implementation Hiding/StaticArrayBad.cs Normal file
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@@ -0,0 +1,8 @@
class Bad
{
public static readonly string[] Foo = { "hello", "world" };
public static void Main(string[] args)
{
Foo[0] = "goodbye";
}
}

4
csharp/ql/src/Bad Practices/Implementation Hiding/StaticArrayFix.cs → csharp/ql/src/Bad Practices/Implementation Hiding/StaticArrayGood.cs
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@@ -1,4 +1,6 @@
class StaticArrayFix
using System.Collections.ObjectModel;
class Good
{
public static readonly ReadOnlyCollection<string> Foo
= new ReadOnlyCollection<string>(new string[] { "hello", "world" });

159
csharp/ql/src/Likely Bugs/Collections/Collection.qll
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@@ -1,159 +0,0 @@
import csharp
string modifyMethodName()
{
result="Add" or
result="AddFirst" or
result="AddLast" or
result="Clear" or
result="Enqueue" or
result="ExceptWith" or
result="Insert" or
result="IntersectWith" or
result="Push" or
result="Remove" or
result="RemoveAt" or
result="RemoveFirst" or
result="RemoveLast" or
result="Set" or
result="SetAll" or
result="SymmetricExceptWith" or
result="UnionWith"
}
class ModifierMethodCall extends MethodCall
{
ModifierMethodCall()
{
getParent() instanceof ExprStmt and
this.getTarget().hasName(modifyMethodName())
}
}
string collectionTypeName()
{
result="ArrayList" or
result="BitArray" or
result="Hashtable" or
result="ICollection" or
result="IDictionary" or
result="IList" or
result="Queue" or
result="ReadOnlyCollectionBase" or
result="SortedList" or
result="Stack"
}
string collectionNamespaceName()
{
result="Mono.Collections" or
result="System.Collections"
}
string genericCollectionNamespaceName()
{
result="Mono.Collections.Generic" or
result="System.Collections.Generic"
}
string genericCollectionTypeName()
{
result="Dictionary<,>" or
result="HashSet<>" or
result="ICollection<>" or
result="IDictionary<,>" or
result="IList<>" or
result="ISet<>" or
result="LinkedList<>" or
result="List<>" or
result="Queue<>" or
result="SortedDictionary<,>" or
result="SortedList<,>" or
result="SortedSet<>" or
result="Stack<>" or
result="SynchronizedCollection<>" or
result="SynchronizedKeyedCollection<>" or
result="SynchronizedReadOnlyCollection<>"
}
predicate isCollectionType(RefType r)
{
r.hasQualifiedName( collectionNamespaceName(), collectionTypeName() ) or
r.(ConstructedType).getUnboundGeneric().hasQualifiedName( genericCollectionNamespaceName(), genericCollectionTypeName() )
}
class EmptyCollectionCreation extends ObjectCreation
{
EmptyCollectionCreation()
{
isCollectionType(getType())
and not hasInitializer()
and getNumberOfArguments()=0
}
}
// Methods that do not mutate a collection.
// These methods are useless on empty collections.
string readonlyMethodName()
{
result="BinarySearch" or
result="Clone" or
result="Contains" or
result="ContainsKey" or
result="ContainsValue" or
result="CopyTo" or
result="Equals" or
result="FixedArray" or
result="FixedSize" or
result="Get" or
result="GetEnumerator" or
result="GetHashCode" or
result="GetRange" or
result="IndexOf" or
result="IsProperSubsetOf" or
result="IsProperSupersetOf" or
result="IsSubsetOf" or
result="IsSupersetOf" or
result="LastIndexOf" or
result="MemberwiseClone" or
result="Peek" or
result="ToArray" or
result="ToString" or
result="TryGetValue"
}
// Methods that do not modify an empty collection.
// These methods are useless on empty collections.
string noAddMethodName()
{
result = readonlyMethodName() or
result="Dequeue" or
result="Pop"
}
// An access that does not modify the collection
predicate readonlyAccess(Access a)
{
// A read-only method call
exists( MethodCall mc | mc.getQualifier()=a | mc.getTarget().hasName(readonlyMethodName()) )
// Any property access
or exists( PropertyAccess pa | pa.getQualifier()=a )
// An indexed read
or exists( IndexerAccess ia | ia.getQualifier()=a | not ia.getParent().(Assignment).getLValue()=ia )
}
// An access that does not add items to a collection
predicate noAddAccess(Access a)
{
readonlyAccess(a)
or exists( MethodCall mc | mc.getQualifier()=a | mc.getTarget().hasName(noAddMethodName()) )
}
// An empty collection is assigned
predicate emptyCollectionAssignment(Access a)
{
exists( Assignment ass | ass.getLValue()=a | ass.getRValue() instanceof EmptyCollectionCreation )
or a.(LocalVariableDeclAndInitExpr).getRValue() instanceof EmptyCollectionCreation
}

8
csharp/ql/src/Likely Bugs/Collections/ReadOnlyContainer.ql
View File

@@ -12,12 +12,12 @@
*/
import csharp
import Collection
import semmle.code.csharp.commons.Collections
from Variable v
where
v.fromSource()
and isCollectionType(v.getType())
and v.getType() instanceof CollectionType
// Publics might get assigned elsewhere
and (v instanceof LocalVariable or v.(Field).isPrivate())
@@ -26,12 +26,12 @@ where
and forall( AssignableDefinition d | v = d.getTarget() | d.getSource() instanceof EmptyCollectionCreation )
// All accesses do not add data.
and forex( Access a | v.getAnAccess()=a | noAddAccess(a) or emptyCollectionAssignment(a) )
and forex( Access a | v.getAnAccess()=a | a instanceof NoAddAccess or a instanceof EmptyInitializationAccess)
// Attributes indicate some kind of reflection
and (not exists( Attribute a | v=a.getTarget() ))
// There is at least one non-assignment access
and noAddAccess(v.getAnAccess())
and v.getAnAccess() instanceof NoAddAccess
select v, "The contents of this container are never initialized."

4
csharp/ql/src/Likely Bugs/Collections/WriteOnlyContainer.ql
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@@ -11,10 +11,10 @@
*/
import csharp
import Collection
import semmle.code.csharp.commons.Collections
from Variable v
where isCollectionType(v.getType())
where v.getType() instanceof CollectionType
and (v instanceof LocalVariable or v = any(Field f | f.isEffectivelyPrivate() or f.isEffectivelyInternal()))
and forex(Access a |
a = v.getAnAccess() |

2
csharp/ql/src/semmle/code/csharp/commons/Assertions.qll
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@@ -1,4 +1,4 @@
/** Provides classed for assertions. */
/** Provides classes for assertions. */
private import semmle.code.csharp.frameworks.system.Diagnostics
private import semmle.code.csharp.frameworks.test.VisualStudio

174
csharp/ql/src/semmle/code/csharp/commons/Collections.qll Normal file
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@@ -0,0 +1,174 @@
/** Provides classes for collections. */
import csharp
private string modifyMethodName() {
result = "Add" or
result = "AddFirst" or
result = "AddLast" or
result = "Clear" or
result = "Enqueue" or
result = "ExceptWith" or
result = "Insert" or
result = "IntersectWith" or
result = "Push" or
result = "Remove" or
result = "RemoveAt" or
result = "RemoveFirst" or
result = "RemoveLast" or
result = "Set" or
result = "SetAll" or
result = "SymmetricExceptWith" or
result = "UnionWith"
}
/** A method call that modifies a collection. */
class ModifierMethodCall extends MethodCall {
ModifierMethodCall() {
this.getParent() instanceof ExprStmt and
this.getTarget().hasName(modifyMethodName())
}
}
/** An access that modifies a collection. */
class CollectionModificationAccess extends Access {
CollectionModificationAccess() {
this = any(ModifierMethodCall mc).getQualifier() or
this = any(ElementWrite ew).getQualifier()
}
}
private string collectionTypeName() {
result = "ArrayList" or
result = "BitArray" or
result = "Hashtable" or
result = "ICollection" or
result = "IDictionary" or
result = "IList" or
result = "Queue" or
result = "ReadOnlyCollectionBase" or
result = "SortedList" or
result = "Stack"
}
private string collectionNamespaceName() {
result = "Mono.Collections" or
result = "System.Collections"
}
private string genericCollectionNamespaceName() {
result = "Mono.Collections.Generic" or
result = "System.Collections.Generic"
}
private string genericCollectionTypeName() {
result = "Dictionary<,>" or
result = "HashSet<>" or
result = "ICollection<>" or
result = "IDictionary<,>" or
result = "IList<>" or
result = "ISet<>" or
result = "LinkedList<>" or
result = "List<>" or
result = "Queue<>" or
result = "SortedDictionary<,>" or
result = "SortedList<,>" or
result = "SortedSet<>" or
result = "Stack<>" or
result = "SynchronizedCollection<>" or
result = "SynchronizedKeyedCollection<>" or
result = "SynchronizedReadOnlyCollection<>"
}
/** A collection type. */
class CollectionType extends RefType {
CollectionType() {
exists(RefType base |
base = this.getABaseType*() |
base.hasQualifiedName(collectionNamespaceName(), collectionTypeName())
or
base.(ConstructedType).getUnboundGeneric().hasQualifiedName(genericCollectionNamespaceName(), genericCollectionTypeName())
)
or
this instanceof ArrayType
}
}
/** An object creation that creates an empty collection. */
class EmptyCollectionCreation extends ObjectCreation {
EmptyCollectionCreation() {
this.getType() instanceof CollectionType and
not this.hasInitializer() and
this.getNumberOfArguments() = 0
}
}
private string readonlyMethodName() {
result = "BinarySearch" or
result = "Clone" or
result = "Contains" or
result = "ContainsKey" or
result = "ContainsValue" or
result = "CopyTo" or
result = "Equals" or
result = "FixedArray" or
result = "FixedSize" or
result = "Get" or
result = "GetEnumerator" or
result = "GetHashCode" or
result = "GetRange" or
result = "IndexOf" or
result = "IsProperSubsetOf" or
result = "IsProperSupersetOf" or
result = "IsSubsetOf" or
result = "IsSupersetOf" or
result = "LastIndexOf" or
result = "MemberwiseClone" or
result = "Peek" or
result = "ToArray" or
result = "ToString" or
result = "TryGetValue"
}
private string noAddMethodName() {
result = readonlyMethodName() or
result = "Dequeue" or
result = "Pop"
}
/** Holds if `a` is an access that does not modify a collection. */
private predicate readonlyAccess(Access a) {
// A read-only method call
exists(MethodCall mc |
mc.getQualifier() = a |
mc.getTarget().hasName(readonlyMethodName())
)
or
// Any property access
a = any(PropertyAccess pa).getQualifier()
or
// An element read
a = any(ElementRead er).getQualifier()
}
/** An access that does not add items to a collection. */
class NoAddAccess extends Access {
NoAddAccess() {
readonlyAccess(this)
or
exists(MethodCall mc |
mc.getQualifier() = this |
mc.getTarget().hasName(noAddMethodName())
)
}
}
/** An access that initializes an empty collection. */
class EmptyInitializationAccess extends Access {
EmptyInitializationAccess() {
exists(AssignableDefinition def |
def.getTargetAccess() = this |
def.getSource() instanceof EmptyCollectionCreation
)
}
}

7
csharp/ql/src/semmle/code/csharp/frameworks/system/Collections.qll
View File

@@ -77,3 +77,10 @@ class SystemCollectionsIEnumeratorInterface extends SystemCollectionsInterface {
/** DEPRECATED. Gets the `System.Collections.IEnumerator` interface. */
deprecated
SystemCollectionsIEnumeratorInterface getSystemCollectionsIEnumeratorInterface() { any() }
/** The `System.Collections.ICollection` interface. */
class SystemCollectionsICollectionInterface extends SystemCollectionsInterface {
SystemCollectionsICollectionInterface() {
this.hasName("ICollection")
}
}

7
csharp/ql/src/semmle/code/csharp/frameworks/system/collections/Generic.qll
View File

@@ -158,3 +158,10 @@ class SystemCollectionsGenericKeyValuePairStruct extends SystemCollectionsGeneri
/** DEPRECATED. Gets the `System.Collections.Generic.KeyValuePair<TKey, TValue>` structure. */
deprecated
SystemCollectionsGenericKeyValuePairStruct getSystemCollectionsGenericKeyValuePairStruct() { any() }
/** The `System.Collections.Generic.ICollection<>` interface. */
class SystemCollectionsGenericICollectionInterface extends SystemCollectionsGenericUnboundGenericInterface {
SystemCollectionsGenericICollectionInterface() {
this.hasName("ICollection<>")
}
}

10
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/AbstractToConcreteCollection/AbstractToConcreteCollection.cs Normal file
View File

@@ -0,0 +1,10 @@
using System.Collections.Generic;
class AbstractToConcreteCollection
{
void M(IEnumerable<string> strings)
{
var list = (List<string>) strings; // BAD
var o = (object) strings; // GOOD
}
}

2
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/AbstractToConcreteCollection/AbstractToConcreteCollection.expected Normal file
View File

@@ -0,0 +1,2 @@
| AbstractToConcreteCollection.cs:7:20:7:41 | (...) ... | Questionable cast from abstract 'IEnumerable<String>' to concrete implementation 'List<String>'. |
| AbstractToConcreteCollectionBad.cs:8:20:8:39 | (...) ... | Questionable cast from abstract 'IEnumerable<String>' to concrete implementation 'List<String>'. |

1
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/AbstractToConcreteCollection/AbstractToConcreteCollection.qlref Normal file
View File

@@ -0,0 +1 @@
Bad Practices/Implementation Hiding/AbstractToConcreteCollection.ql

21
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/AbstractToConcreteCollection/AbstractToConcreteCollectionBad.cs Normal file
View File

@@ -0,0 +1,21 @@
using System.Collections.Generic;
class Bad
{
public static void Main(string[] args)
{
var names = GetNames();
var list = (List<string>) names;
list.Add("Eve");
}
static IEnumerable<string> GetNames()
{
var ret = new List<string>()
{
"Alice",
"Bob"
};
return ret;
}
}

18
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentation.cs Normal file
View File

@@ -0,0 +1,18 @@
using System;
class ExposeRepresentation
{
class Range
{
private int[] rarray = new int[2];
public void Set(int[] a) { rarray = a; }
}
public static void Main(string[] args)
{
var a = new int[] { 0, 1 };
var r = new Range();
r.Set(a); // BAD
a[0] = 500;
}
}

2
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentation.expected Normal file
View File

@@ -0,0 +1,2 @@
| ExposeRepresentation.cs:8:21:8:23 | Set | 'Set' exposes the internal representation stored in field 'rarray'. The value may be modified $@. | ExposeRepresentation.cs:16:9:16:9 | ExposeRepresentation.cs:16:9:16:9 | through the variable a |
| ExposeRepresentationBad.cs:18:22:18:24 | Get | 'Get' exposes the internal representation stored in field 'rarray'. The value may be modified $@. | ExposeRepresentationBad.cs:24:23:24:29 | ExposeRepresentationBad.cs:24:23:24:29 | after this call to Get |

1
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentation.qlref Normal file
View File

@@ -0,0 +1 @@
Bad Practices/Implementation Hiding/ExposeRepresentation.ql

29
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentationBad.cs Normal file
View File

@@ -0,0 +1,29 @@
using System;
class Bad
{
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] Get() => rarray;
}
public static void Main(string[] args)
{
var r = new Range(1, 10);
var r_range = r.Get();
r_range[0] = 500;
Console.WriteLine("Min: " + r.Get()[0] + " Max: " + r.Get()[1]);
// prints "Min: 500 Max: 10"
}
}

22
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentationGood1.cs Normal file
View File

@@ -0,0 +1,22 @@
using System.Collections.ObjectModel;
class Good1
{
class Range
{
private ReadOnlyCollection<int> rarray = new ReadOnlyCollection<int>(new int[2]);
public Range(int min, int max)
{
if (min <= max)
{
int[] rarray = new int[2];
rarray[0] = min;
rarray[1] = max;
this.rarray = new ReadOnlyCollection<int>(rarray);
}
}
public ReadOnlyCollection<int> Get() => rarray;
}
}

29
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/ExposeRepresentation/ExposeRepresentationGood2.cs Normal file
View File

@@ -0,0 +1,29 @@
using System;
class Good2
{
class Range
{
private int[] rarray = new int[2];
public Range(int min, int max)
{
if (min <= max)
{
rarray[0] = min;
rarray[1] = max;
}
}
public int[] Get() => (int[])rarray.Clone();
}
public static void Main(string[] args)
{
Range a = new Range(1, 10);
int[] a_range = a.Get();
a_range[0] = 500;
Console.WriteLine("Min: " + a.Get()[0] + " Max: " + a.Get()[1]);
// prints "Min: 1 Max: 10"
}
}

3
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray.expected
View File

@@ -1,3 +0,0 @@
| StaticArray.cs:13:34:13:47 | NonEmptyArray1 | NonEmptyArray1 is a static array vulnerable to mutation. |
| StaticArray.cs:17:34:17:47 | NonEmptyArray3 | NonEmptyArray3 is a static array vulnerable to mutation. |
| StaticArray.cs:19:34:19:38 | Array | Array is a static array vulnerable to mutation. |

0
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray.cs → csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray/StaticArray.cs
View File

4
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray/StaticArray.expected Normal file
View File

@@ -0,0 +1,4 @@
| StaticArray.cs:13:34:13:47 | NonEmptyArray1 | The array constant 'NonEmptyArray1' is vulnerable to mutation. |
| StaticArray.cs:17:34:17:47 | NonEmptyArray3 | The array constant 'NonEmptyArray3' is vulnerable to mutation. |
| StaticArray.cs:19:34:19:38 | Array | The array constant 'Array' is vulnerable to mutation. |
| StaticArrayBad.cs:3:37:3:39 | Foo | The array constant 'Foo' is vulnerable to mutation. |

0
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray.qlref → csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray/StaticArray.qlref
View File

8
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray/StaticArrayBad.cs Normal file
View File

@@ -0,0 +1,8 @@
class Bad
{
public static readonly string[] Foo = { "hello", "world" };
public static void Main(string[] args)
{
Foo[0] = "goodbye";
}
}

11
csharp/ql/test/query-tests/Bad Practices/Implementation Hiding/StaticArray/StaticArrayGood.cs Normal file
View File

@@ -0,0 +1,11 @@
using System.Collections.ObjectModel;
class Good
{
public static readonly ReadOnlyCollection<string> Foo
= new ReadOnlyCollection<string>(new string[] { "hello", "world" });
public static void Main(string[] args)
{
}
}