Module ExternalFlow

INTERNAL use only. This is an experimental API subject to change without notice.

Provides classes and predicates for dealing with MaD flow models specified in data extensions and CSV format.

The CSV specification has the following columns:

• Sources: package; type; subtypes; name; signature; ext; output; kind; provenance
• Sinks: package; type; subtypes; name; signature; ext; input; kind; provenance
• Summaries: package; type; subtypes; name; signature; ext; input; output; kind; provenance

The interpretation of a row is similar to API-graphs with a left-to-right reading.

1. The package column selects a package.

2. The type column selects a type within that package.

3. The subtypes is a boolean that indicates whether to jump to an arbitrary subtype of that type.

4. The name column optionally selects a specific named member of the type.

5. The signature column is always empty.

6. The ext column is always empty.

7. The input column specifies how data enters the element selected by the first 6 columns, and the output column specifies how data leaves the element selected by the first 6 columns. An input can be either "", “Argument[n]”, or “Argument[n1..n2]”:

   • "": Selects a write to the selected element in case this is a field.
   • “Argument[n]”: Selects an argument in a call to the selected element. The arguments are zero-indexed, and -1 specifies the qualifier.
   • “Argument[n1..n2]”: Similar to “Argument[n]” but selects any argument in the given range. The range is inclusive at both ends.

   An output can be either "", “Argument[n]”, “Argument[n1..n2]”, “Parameter”, “Parameter[n]”, “Parameter[n1..n2]”, , “ReturnValue”, “ReturnValue[n]”, or “ReturnValue[n1..n2]”:

   • "": Selects a read of a selected field.
   • “Argument[n]”: Selects the post-update value of an argument in a call to the selected element. That is, the value of the argument after the call returns. The arguments are zero-indexed, and -1 specifies the qualifier.
   • “Argument[n1..n2]”: Similar to “Argument[n]” but select any argument in the given range. The range is inclusive at both ends.
   • “Parameter”: Selects the value of a parameter of the selected element.
   • “Parameter[n]”: Similar to “Parameter” but restricted to a specific numbered parameter (zero-indexed, and -1 specifies the value of this).
   • “Parameter[n1..n2]”: Similar to “Parameter[n]” but selects any parameter in the given range. The range is inclusive at both ends.
   • “ReturnValue”: Selects the first value being returned by the selected element. This requires that the selected element is a method with a body.
   • “ReturnValue[n]”: Similar to “ReturnValue” but selects the specified return value. The return values are zero-indexed
   • “ReturnValue[n1..n2]”: Similar to “ReturnValue[n]” but selects any return value in the given range. The range is inclusive at both ends.

   For summaries, input and output may be suffixed by any number of the following, separated by “.”:

   • “Field[pkg.className.fieldname]”: Selects the contents of the field f which satisfies f.hasQualifiedName(pkg, className, fieldname).
   • “SyntheticField[f]”: Selects the contents of the synthetic field f.
   • “ArrayElement”: Selects an element in an array or slice.
   • “Element”: Selects an element in a collection.
   • “MapKey”: Selects a key in a map.
   • “MapValue”: Selects a value in a map.
   • “Dereference”: Selects the value referenced by a pointer.

8. The kind column is a tag that can be referenced from QL to determine to which classes the interpreted elements should be added. For example, for sources “remote” indicates a default remote flow source, and for summaries “taint” indicates a default additional taint step and “value” indicates a globally applicable value-preserving step.