move model of printf style calls to StringFormatters.qll

Author: erik-krogh

ruby/ql/lib/codeql/ruby/Frameworks.qll

@@ -23,3 +23,4 @@ private import codeql.ruby.frameworks.HttpClients
 private import codeql.ruby.frameworks.XmlParsing
 private import codeql.ruby.frameworks.ActionDispatch
 private import codeql.ruby.frameworks.PosixSpawn
+private import codeql.ruby.frameworks.StringFormatters

ruby/ql/lib/codeql/ruby/frameworks/StringFormatters.qll

@@ -0,0 +1,70 @@
+/**
+ * Provides classes for modeling string formatting libraries.
+ */
+
+private import codeql.ruby.ast.Call
+private import codeql.ruby.DataFlow
+private import codeql.ruby.ApiGraphs
+private import codeql.ruby.frameworks.core.IO
+
+/**
+ * A call to `printf` or `sprintf`.
+ */
+abstract class PrintfStyleCall extends DataFlow::CallNode {
+  // We assume that most printf-like calls have the signature f(format_string, args...)
+  /**
+   * Gets the format string of this call.
+   */
+  DataFlow::Node getFormatString() { result = this.getArgument(0) }
+
+  /**
+   * Gets then `n`th formatted argument of this call.
+   */
+  DataFlow::Node getFormatArgument(int n) { n >= 0 and result = this.getArgument(n + 1) }
+}
+
+/**
+ * A call to `Kernel.printf`.
+ */
+class KernelPrintfCall extends PrintfStyleCall {
+  KernelPrintfCall() {
+    this = API::getTopLevelMember("Kernel").getAMethodCall("printf")
+    or
+    this.asExpr().getExpr() instanceof UnknownMethodCall and
+    this.getMethodName() = "printf"
+  }
+
+  // Kernel#printf supports two signatures:
+  //   printf(io, string, ...)
+  //   printf(string, ...)
+  override DataFlow::Node getFormatString() {
+    // Because `printf` has two different signatures, we can't be sure which
+    // argument is the format string, so we use a heuristic:
+    // If the first argument has a string value, then we assume it is the format string.
+    // Otherwise we treat both the first and second args as the format string.
+    if this.getArgument(0).getExprNode().getConstantValue().isString(_)
+    then result = this.getArgument(0)
+    else result = this.getArgument([0, 1])
+  }
+}
+
+/**
+ * A call to `Kernel.sprintf`.
+ */
+class KernelSprintfCall extends PrintfStyleCall {
+  KernelSprintfCall() {
+    this = API::getTopLevelMember("Kernel").getAMethodCall("sprintf")
+    or
+    this.asExpr().getExpr() instanceof UnknownMethodCall and
+    this.getMethodName() = "sprintf"
+  }
+}
+
+/**
+ * A call to `IO#printf`.
+ */
+class IOPrintfCall extends PrintfStyleCall {
+  IOPrintfCall() {
+    this.getReceiver() instanceof IO::IOInstance and this.getMethodName() = "printf"
+  }
+}

ruby/ql/lib/codeql/ruby/security/TaintedFormatStringSpecific.qll

@@ -2,82 +2,8 @@
  * Provides Ruby-specific imports and classes needed for `TaintedFormatStringQuery` and `TaintedFormatStringCustomizations`.
  */
 
-import codeql.ruby.AST
+import codeql.ruby.frameworks.StringFormatters
 import codeql.ruby.DataFlow
 import codeql.ruby.dataflow.RemoteFlowSources
-import codeql.ruby.ApiGraphs
 import codeql.ruby.TaintTracking
-private import codeql.ruby.frameworks.Files
-private import codeql.ruby.frameworks.core.IO
-private import codeql.ruby.controlflow.CfgNodes
-
-/**
- * A call to `printf` or `sprintf`.
- */
-abstract class PrintfStyleCall extends DataFlow::CallNode {
-  // We assume that most printf-like calls have the signature f(format_string, args...)
-  /**
-   * Gets the format string of this call.
-   */
-  DataFlow::Node getFormatString() { result = this.getArgument(0) }
-
-  /**
-   * Gets then `n`th formatted argument of this call.
-   */
-  DataFlow::Node getFormatArgument(int n) { n >= 0 and result = this.getArgument(n + 1) }
-
-  /** Holds if this call returns the formatted string. */
-  predicate returnsFormatted() { any() }
-}
-
-/**
- * A call to `Kernel.printf`.
- */
-class KernelPrintfCall extends PrintfStyleCall {
-  KernelPrintfCall() {
-    this = API::getTopLevelMember("Kernel").getAMethodCall("printf")
-    or
-    this.asExpr().getExpr() instanceof UnknownMethodCall and
-    this.getMethodName() = "printf"
-  }
-
-  // Kernel#printf supports two signatures:
-  //   printf(io, string, ...)
-  //   printf(string, ...)
-  override DataFlow::Node getFormatString() {
-    // Because `printf` has two different signatures, we can't be sure which
-    // argument is the format string, so we use a heuristic:
-    // If the first argument has a string value, then we assume it is the format string.
-    // Otherwise we treat both the first and second args as the format string.
-    if this.getArgument(0).getExprNode().getConstantValue().isString(_)
-    then result = this.getArgument(0)
-    else result = this.getArgument([0, 1])
-  }
-
-  override predicate returnsFormatted() { none() }
-}
-
-/**
- * A call to `Kernel.sprintf`.
- */
-class KernelSprintfCall extends PrintfStyleCall {
-  KernelSprintfCall() {
-    this = API::getTopLevelMember("Kernel").getAMethodCall("sprintf")
-    or
-    this.asExpr().getExpr() instanceof UnknownMethodCall and
-    this.getMethodName() = "sprintf"
-  }
-
-  override predicate returnsFormatted() { any() }
-}
-
-/**
- * A call to `IO#printf`.
- */
-class IOPrintfCall extends PrintfStyleCall {
-  IOPrintfCall() {
-    this.getReceiver() instanceof IO::IOInstance and this.getMethodName() = "printf"
-  }
-
-  override predicate returnsFormatted() { none() }
-}
+import codeql.ruby.DataFlow