It can be invoked programmatically by running: from polyfile.magic import MagicMatcher with open ( "file_to_test" , "rb" ) as f : # the default instance automatically loads all file definitions for match in MagicMatcher . DEFAULT_INSTANCE . match ( f . read ()): for mimetype in match . mimetypes : print ( f "Matched MIME: { mimetype } " ) print ( f "Match string: { match !s} " ) GDB. You can enter this debugger by passing the --debugger or -db argument to PolyFile. It is useful for both You can read the minimal and—as we have discovered in our cleanroom implementation— incomplete documentation by running Optional path to output a Graphviz .dot file representing the type hierarchy extracted from PolyFile Full usage instructions follow: usage: polyfile [-h] [--format {file,mime,html,json,sbud}] [--output OUTPUT]

To load a specific or custom file definition: list_of_paths_to_definitions = [ "def1" , "def2" ] matcher = MagicMatcher . parse ( * list_of_paths_to_definitions ) with open ( "file_to_test" , "rb" ) as f : for match in matcher . match ( f . read ()): ... Debugging the libmagic DSL PolyFile has several options for outputting its results, specified by its --format option. For computer-readable output, PolyFile has an extension of the SBuD JSON format described in the documentation. Prior to version 0.5.0 this was the default output format of PolyFile. However, now the default output format is to mimic the behavior of the file command. To maintain the original behavior, use the --format sbud option. libMagic Implementation To be used in conjunction with `--dataflow`. If enabled, only functions in the dataflow graph if they operated on the tainted bytes. This can result in a disjoint dataflow graph. For each type within the semantic hierarchy, a list of functions that are “most specialized” in processing that type.most specialized” in operating on that type. This is an active area of academic research and is likely to change in As mentioned above, polymerge attempts to match each semantic type of the input file to a set of functions that are explicitly match against the given filetype or filetype wildcard (default is to match against all filetypes) curl -v --silent https://www.sultanik.com/files/ESultanikResume.pdf | polyfile --html ESultanikResume.html - libmagic has an esoteric, poorly documented domain-specific language (DSL) for specifying its matching signatures.

file format’s grammar. This is an area of active research intended to achieve fully automated grammar extraction from a debugger, -db drop into an interactive debugger for libmagic file definition matching and PolyFile parsing identification rather than the libmagic file definitions. This proved to be very slow (since TrID has many duplicatedefinition, determine why a specific file fails to be classified as the expected MIME type, or step through a parser. cfg CFG, -c CFG Optional path to output a Graphviz .dot file representing the control flow graph of the program trace For each function, calculate the Shannon entropy of the different types on which that function operated; man 5 magic. PolyFile implements an interactive debugger for stepping through the DSL specifications, modeled after

demangle Demangle C++ function names in the CFG (requires that PolyFile was installed with the `demangle` option, or that the `cxxfilt` Python module is installed.) A separate utility called polymerge is installed with PolyFile specifically designed to merge the output of both

For an example that exercises all of these file formats, run: curl -v --silent https://www.sultanik.com/files/ESultanikResume.pdf | polyfile --html ESultanikResume.html - TrID matching code is still shipped with PolyFile and can be invoked programmatically, but it is not used by default. Output Format no-debug-python by default, the `--debugger` option will break on custom matchers and prompt to debug using PDB. This option will suppress those prompts. entries) and prone to false positives (since TrID's file definitions are much simpler than libmagic's). The original For the CFG generation options, only render functions that participated in dataflow. `--dataflow 10` means that only functions in the dataflow related to byte 10 should be included. `--dataflow 10:30` means that only functions operating on bytes 10 through 29 should be included. The beginning or end of a range can be omitted and will default to the beginning and end of the file, respectively. Multiple `--dataflow` ranges can be specified. `--dataflow :` will render the CFG only with functions that operated on tainted bytes. Omitting `--dataflow` will produce a CFG containing all functions.