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Refactored cleartext storage libraries
1 parent 93daaf5 commit a30554e

7 files changed

Lines changed: 329 additions & 15 deletions

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‎java/ql/lib/semmle/code/java/security/CleartextStorageClassQuery.qll‎

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/** Provides classes and predicates to reason about cleartext storage in serializable classes. */
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import java
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import semmle.code.java.frameworks.JAXB
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import semmle.code.java.dataflow.DataFlow
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import semmle.code.java.dataflow.DataFlow2
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import semmle.code.java.security.CleartextStorageQuery
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import semmle.code.java.security.CleartextStoragePropertiesQuery
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private class ClassCleartextStorageSink extends CleartextStorageSink {
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ClassCleartextStorageSink() { this.asExpr() = getInstanceInput(_, _) }
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}
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/** The instantiation of a storable class, which can be stored to disk. */
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abstract class ClassStore extends Storable, ClassInstanceExpr {
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/** Gets an input, for example `input` in `instance.password = input`. */
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override Expr getAnInput() {
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exists(ClassStoreFlowConfig conf, DataFlow::Node instance |
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conf.hasFlow(DataFlow::exprNode(this), instance) and
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result = getInstanceInput(instance, this.getConstructor().getDeclaringType())
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)
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}
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}
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/**
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* The instantiation of a serializable class, which can be stored to disk.
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*
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* Only includes tainted instances where data from a `SensitiveSource` may flow
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* to an input of the `Serializable`.
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*/
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private class Serializable extends ClassStore {
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Serializable() {
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this.getConstructor().getDeclaringType().getASupertype*() instanceof TypeSerializable and
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// `Properties` are `Serializable`, but handled elsewhere.
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not this instanceof Properties and
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// restrict attention to tainted instances
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exists(SensitiveSource data |
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data.flowsToCached(getInstanceInput(_, this.getConstructor().getDeclaringType()))
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)
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}
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/** Gets a store, for example `outputStream.writeObject(instance)`. */
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override Expr getAStore() {
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exists(ClassStoreFlowConfig conf, DataFlow::Node n |
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serializableStore(n, result) and
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conf.hasFlow(DataFlow::exprNode(this), n)
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)
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}
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}
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/** The instantiation of a marshallable class, which can be stored to disk as XML. */
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private class Marshallable extends ClassStore {
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Marshallable() { this.getConstructor().getDeclaringType() instanceof JAXBElement }
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/** Gets a store, for example `marshaller.marshal(instance)`. */
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override Expr getAStore() {
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exists(ClassStoreFlowConfig conf, DataFlow::Node n |
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marshallableStore(n, result) and
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conf.hasFlow(DataFlow::exprNode(this), n)
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)
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}
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}
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/** Gets an input, for example `input` in `instance.password = input`. */
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private Expr getInstanceInput(DataFlow::Node instance, RefType t) {
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exists(AssignExpr a, FieldAccess fa |
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instance = DataFlow::getFieldQualifier(fa) and
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a.getDest() = fa and
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a.getSource() = result and
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fa.getField().getDeclaringType() = t
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|
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t.getASourceSupertype*() instanceof TypeSerializable or
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t instanceof JAXBElement
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)
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}
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private class ClassStoreFlowConfig extends DataFlow2::Configuration {
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ClassStoreFlowConfig() { this = "ClassStoreFlowConfig" }
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override predicate isSource(DataFlow::Node src) { src.asExpr() instanceof ClassStore }
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override predicate isSink(DataFlow::Node sink) {
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exists(getInstanceInput(sink, _)) or
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serializableStore(sink, _) or
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marshallableStore(sink, _)
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}
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override int fieldFlowBranchLimit() { result = 1 }
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}
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private predicate serializableStore(DataFlow::Node instance, Expr store) {
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exists(MethodAccess m |
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store = m and
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m.getMethod() instanceof WriteObjectMethod and
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instance.asExpr() = m.getArgument(0)
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)
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}
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private predicate marshallableStore(DataFlow::Node instance, Expr store) {
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exists(MethodAccess m |
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store = m and
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m.getMethod() instanceof JAXBMarshalMethod and
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instance.asExpr() = m.getArgument(0)
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)
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}

‎java/ql/lib/semmle/code/java/security/CleartextStorageCookieQuery.qll‎

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/** Provides classes and predicates to reason about cleartext storage in cookies. */
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import java
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import semmle.code.java.dataflow.DataFlow
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import semmle.code.java.dataflow.DataFlow3
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import semmle.code.java.security.CleartextStorageQuery
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private class CookieCleartextStorageSink extends CleartextStorageSink {
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CookieCleartextStorageSink() { this.asExpr() = cookieInput(_) }
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}
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/** The instantiation of a cookie, which can act as storage. */
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class Cookie extends Storable, ClassInstanceExpr {
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Cookie() {
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this.getConstructor().getDeclaringType().getQualifiedName() = "javax.servlet.http.Cookie"
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}
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/** Gets an input, for example `input` in `new Cookie("...", input);`. */
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override Expr getAnInput() { result = cookieInput(this) }
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/** Gets a store, for example `response.addCookie(cookie);`. */
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override Expr getAStore() {
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exists(CookieToStoreFlowConfig conf, DataFlow::Node n |
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cookieStore(n, result) and
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conf.hasFlow(DataFlow::exprNode(this), n)
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)
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}
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}
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private predicate cookieStore(DataFlow::Node cookie, Expr store) {
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exists(MethodAccess m, Method def |
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m.getMethod() = def and
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def.getName() = "addCookie" and
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def.getDeclaringType().getQualifiedName() = "javax.servlet.http.HttpServletResponse" and
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store = m and
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cookie.asExpr() = m.getAnArgument()
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)
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}
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private class CookieToStoreFlowConfig extends DataFlow3::Configuration {
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CookieToStoreFlowConfig() { this = "CookieToStoreFlowConfig" }
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override predicate isSource(DataFlow::Node src) { src.asExpr() instanceof Cookie }
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override predicate isSink(DataFlow::Node sink) { cookieStore(sink, _) }
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}
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private Expr cookieInput(Cookie c) { result = c.getArgument(1) }

‎java/ql/lib/semmle/code/java/security/CleartextStoragePropertiesQuery.qll‎

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/** Provides classes and predicates to reason about cleartext storage in Properties files. */
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import java
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import semmle.code.java.dataflow.DataFlow
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import semmle.code.java.frameworks.Properties
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import semmle.code.java.security.CleartextStorageQuery
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private class PropertiesCleartextStorageSink extends CleartextStorageSink {
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PropertiesCleartextStorageSink() {
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exists(MethodAccess m |
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m.getMethod() instanceof PropertiesSetPropertyMethod and this.asExpr() = m.getArgument(1)
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)
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}
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}
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/** The instantiation of a `Properties` object, which can be stored to disk. */
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class Properties extends Storable, ClassInstanceExpr {
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Properties() { this.getConstructor().getDeclaringType() instanceof TypeProperty }
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/** Gets an input, for example `input` in `props.setProperty("password", input);`. */
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override Expr getAnInput() {
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exists(PropertiesFlowConfig conf, DataFlow::Node n |
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propertiesInput(n, result) and
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conf.hasFlow(DataFlow::exprNode(this), n)
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)
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}
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/** Gets a store, for example `props.store(outputStream, "...")`. */
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override Expr getAStore() {
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exists(PropertiesFlowConfig conf, DataFlow::Node n |
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propertiesStore(n, result) and
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conf.hasFlow(DataFlow::exprNode(this), n)
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)
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}
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}
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private predicate propertiesInput(DataFlow::Node prop, Expr input) {
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exists(MethodAccess m |
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m.getMethod() instanceof PropertiesSetPropertyMethod and
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input = m.getArgument(1) and
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prop.asExpr() = m.getQualifier()
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)
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}
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private predicate propertiesStore(DataFlow::Node prop, Expr store) {
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exists(MethodAccess m |
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m.getMethod() instanceof PropertiesStoreMethod and
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store = m and
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prop.asExpr() = m.getQualifier()
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)
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}
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private class PropertiesFlowConfig extends DataFlow::Configuration {
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PropertiesFlowConfig() { this = "PropertiesFlowConfig" }
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override predicate isSource(DataFlow::Node src) { src.asExpr() instanceof Properties }
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override predicate isSink(DataFlow::Node sink) {
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propertiesInput(sink, _) or
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propertiesStore(sink, _)
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}
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}

‎java/ql/lib/semmle/code/java/security/CleartextStorageQuery.qll‎

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/** Provides classes and predicates to reason about cleartext storage vulnerabilities. */
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import java
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private import semmle.code.java.dataflow.DataFlow4
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private import semmle.code.java.dataflow.TaintTracking
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private import semmle.code.java.security.SensitiveActions
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/** A sink representing persistent storage that saves data in clear text. */
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abstract class CleartextStorageSink extends DataFlow::Node { }
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/** A sanitizer for flows tracking sensitive data being stored in persistent storage. */
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abstract class CleartextStorageSanitizer extends DataFlow::Node { }
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/** An additional taint step for sensitive data flowing into cleartext storage. */
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class CleartextStorageAdditionalTaintStep extends Unit {
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abstract predicate step(DataFlow::Node n1, DataFlow::Node n2);
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}
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/** Class for expressions that may represent 'sensitive' information */
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class SensitiveSource extends Expr {
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SensitiveSource() {
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// SensitiveExpr is abstract, this lets us inherit from it without
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// being a technical subclass
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this instanceof SensitiveExpr
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}
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/** Holds if this source flows to the `sink`. */
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cached
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predicate flowsToCached(Expr sink) {
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exists(SensitiveSourceFlowConfig conf |
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conf.hasFlow(DataFlow::exprNode(this), DataFlow::exprNode(sink))
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)
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}
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}
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/**
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* Class representing entities that may be stored/written, with methods
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* for finding values that are stored within them, and cases
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* of the entity being stored.
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*/
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abstract class Storable extends Call {
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/** Gets an "input" that is stored in an instance of this class. */
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abstract Expr getAnInput();
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/** Gets an expression where an instance of this class is stored (e.g. to disk). */
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abstract Expr getAStore();
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}
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private class SensitiveSourceFlowConfig extends TaintTracking::Configuration {
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SensitiveSourceFlowConfig() { this = "SensitiveSourceFlowConfig" }
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override predicate isSource(DataFlow::Node src) { src.asExpr() instanceof SensitiveExpr }
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override predicate isSink(DataFlow::Node sink) { sink instanceof CleartextStorageSink }
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override predicate isSanitizer(DataFlow::Node sanitizer) {
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sanitizer instanceof CleartextStorageSanitizer
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}
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override predicate isAdditionalTaintStep(DataFlow::Node n1, DataFlow::Node n2) {
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any(CleartextStorageAdditionalTaintStep c).step(n1, n2)
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}
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}
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private class DefaultCleartextStorageSanitizer extends CleartextStorageSanitizer {
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DefaultCleartextStorageSanitizer() {
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this.getType() instanceof NumericType or
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this.getType() instanceof BooleanType or
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exists(EncryptedValueFlowConfig conf | conf.hasFlow(_, this))
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}
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}
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/**
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* Method call for encrypting sensitive information. As there are various implementations of
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* encryption (reversible and non-reversible) from both JDK and third parties, this class simply
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* checks method name to take a best guess to reduce false positives.
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*/
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private class EncryptedSensitiveMethodAccess extends MethodAccess {
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EncryptedSensitiveMethodAccess() {
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this.getMethod().getName().toLowerCase().matches(["%encrypt%", "%hash%", "%digest%"])
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}
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}
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/** Flow configuration for encryption methods flowing to inputs of persistent storage. */
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private class EncryptedValueFlowConfig extends DataFlow4::Configuration {
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EncryptedValueFlowConfig() { this = "EncryptedValueFlowConfig" }
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override predicate isSource(DataFlow::Node src) {
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src.asExpr() instanceof EncryptedSensitiveMethodAccess
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}
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override predicate isSink(DataFlow::Node sink) { sink instanceof CleartextStorageSink }
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}
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/** A taint step for `EditText.toString` in Android. */
96+
private class AndroidEditTextCleartextStorageStep extends CleartextStorageAdditionalTaintStep {
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override predicate step(DataFlow::Node n1, DataFlow::Node n2) {
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// EditText.getText() return type is parsed as `Object`, so we need to
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// add a taint step for `Object.toString` to model `editText.getText().toString()`
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exists(MethodAccess ma, Method m |
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ma.getMethod() = m and
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m.getDeclaringType() instanceof TypeObject and
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m.hasName("toString")
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|
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n1.asExpr() = ma.getQualifier() and n2.asExpr() = ma
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)
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}
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}

‎java/ql/src/Security/CWE/CWE-312/CleartextStorageClass.ql‎

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@@ -12,15 +12,12 @@
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*/
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1414
import java
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import SensitiveStorage
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import semmle.code.java.security.CleartextStorageClassQuery
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1717
from SensitiveSource data, ClassStore s, Expr input, Expr store
1818
where
1919
input = s.getAnInput() and
2020
store = s.getAStore() and
21-
data.flowsToCached(input) and
22-
// Exclude results in test code.
23-
not testMethod(store.getEnclosingCallable()) and
24-
not testMethod(data.getEnclosingCallable())
21+
data.flowsToCached(input)
2522
select store, "Storable class $@ containing $@ is stored here. Data was added $@.", s, s.toString(),
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data, "sensitive data", input, "here"

‎java/ql/src/Security/CWE/CWE-312/CleartextStorageCookie.ql‎

Lines changed: 2 additions & 5 deletions
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@@ -11,15 +11,12 @@
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*/
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1313
import java
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import SensitiveStorage
14+
import semmle.code.java.security.CleartextStorageCookieQuery
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1616
from SensitiveSource data, Cookie s, Expr input, Expr store
1717
where
1818
input = s.getAnInput() and
1919
store = s.getAStore() and
20-
data.flowsToCached(input) and
21-
// Exclude results in test code.
22-
not testMethod(store.getEnclosingCallable()) and
23-
not testMethod(data.getEnclosingCallable())
20+
data.flowsToCached(input)
2421
select store, "Cookie $@ containing $@ is stored here. Data was added $@.", s, s.toString(), data,
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"sensitive data", input, "here"

‎java/ql/src/Security/CWE/CWE-312/CleartextStorageProperties.ql‎

Lines changed: 2 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -11,15 +11,12 @@
1111
*/
1212

1313
import java
14-
import SensitiveStorage
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import semmle.code.java.security.CleartextStoragePropertiesQuery
1515

1616
from SensitiveSource data, Properties s, Expr input, Expr store
1717
where
1818
input = s.getAnInput() and
1919
store = s.getAStore() and
20-
data.flowsToCached(input) and
21-
// Exclude results in test code.
22-
not testMethod(store.getEnclosingCallable()) and
23-
not testMethod(data.getEnclosingCallable())
20+
data.flowsToCached(input)
2421
select store, "'Properties' class $@ containing $@ is stored here. Data was added $@.", s,
2522
s.toString(), data, "sensitive data", input, "here"

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