C++: Un-private a few classes that are now used by the current DefaultSafeExternalAPIFunction implementation.

geoffw0 · geoffw0 · commit 7015a9cf5301 · 2020-11-23T14:47:22.000Z
diff --git a/cpp/ql/src/Security/CWE/CWE-020/SafeExternalAPIFunction.qll b/cpp/ql/src/Security/CWE/CWE-020/SafeExternalAPIFunction.qll
@@ -13,6 +13,7 @@ abstract class SafeExternalAPIFunction extends Function { }
 /** The default set of "safe" external APIs. */
 private class DefaultSafeExternalAPIFunction extends SafeExternalAPIFunction {
   DefaultSafeExternalAPIFunction() {
+    // implementation note: this should be based on the properties of public interfaces, rather than accessing implementation classes directly.  When we've done that, the three classes referenced here should be made fully private.
     this instanceof PureStrFunction or
     this instanceof StrLenFunction or
     this instanceof PureMemFunction
diff --git a/cpp/ql/src/semmle/code/cpp/models/implementations/Pure.qll b/cpp/ql/src/semmle/code/cpp/models/implementations/Pure.qll
@@ -3,14 +3,16 @@ import semmle.code.cpp.models.interfaces.Taint
 import semmle.code.cpp.models.interfaces.Alias
 import semmle.code.cpp.models.interfaces.SideEffect
 
-/** Pure string functions. */
-private class PureStrFunction extends AliasFunction, ArrayFunction, TaintFunction, SideEffectFunction {
+/**
+ * Pure string functions.
+ *
+ * INTERNAL: do not use.
+ */
+class PureStrFunction extends AliasFunction, ArrayFunction, TaintFunction, SideEffectFunction {
   PureStrFunction() {
-    hasGlobalOrStdName([
-        "atof", "atoi", "atol", "atoll", "strcasestr", "strchnul", "strchr", "strchrnul", "strstr",
-        "strpbrk", "strcmp", "strcspn", "strncmp", "strrchr", "strspn", "strtod", "strtof",
-        "strtol", "strtoll", "strtoq", "strtoul"
-      ])
+    hasGlobalOrStdName(["atof", "atoi", "atol", "atoll", "strcasestr", "strchnul", "strchr",
+          "strchrnul", "strstr", "strpbrk", "strcmp", "strcspn", "strncmp", "strrchr", "strspn",
+          "strtod", "strtof", "strtol", "strtoll", "strtoq", "strtoul"])
   }
 
   override predicate hasArrayInput(int bufParam) {
@@ -59,8 +61,12 @@ private class PureStrFunction extends AliasFunction, ArrayFunction, TaintFunctio
   }
 }
 
-/** String standard `strlen` function, and related functions for computing string lengths. */
-private class StrLenFunction extends AliasFunction, ArrayFunction, SideEffectFunction {
+/**
+ * String standard `strlen` function, and related functions for computing string lengths.
+ *
+ * INTERNAL: do not use.
+ */
+class StrLenFunction extends AliasFunction, ArrayFunction, SideEffectFunction {
   StrLenFunction() {
     hasGlobalOrStdName(["strlen", "strnlen", "wcslen"])
     or
@@ -110,7 +116,11 @@ private class PureFunction extends TaintFunction, SideEffectFunction {
   override predicate hasOnlySpecificWriteSideEffects() { any() }
 }
 
-/** Pure raw-memory functions. */
+/**
+ * Pure raw-memory functions.
+ *
+ * INTERNAL: do not use.
+ */
 class PureMemFunction extends AliasFunction, ArrayFunction, TaintFunction, SideEffectFunction {
   PureMemFunction() { hasGlobalOrStdName(["memchr", "memrchr", "rawmemchr", "memcmp", "memmem"]) }
 
