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Purpose

This tool does check compiled elf-files (and all dependencies) against given rules. Objectives are

  • check for discouraged functions (e.g. strcpy)
  • check for combinations of symbols (e.g. mutex and pthreads)

Usage

usage: pysymbolcheck [-h] [--libpath LIBPATH] rules file

Eval symbols of a binary against given rules

positional arguments:
  rules              Path to a rule file
  file               File to parse

optional arguments:
  -h, --help         show this help message and exit
  --libpath LIBPATH  ":" separated path to lookup libraries

Rule file format

a rule file consists of a json-array, like this

[]

within this n element of the following can be added

{ "severity": "error", "id": "A_Unique_ID", "msg": "some message", "rule", "<rule>" }

for severity it is advised to use only info, warning or error

Rule definition

A rule can consist of any logical combined operation such as

((A && B) || (C && D )) && !E

to get the needed information following keywords are implemented

keyword variables purpose example
AVAILABLE() symbol-name check if a symbol is defined in the binary or any referenced lib AVAILABLE(strncpy)
USED() symbol-name check if a symbol is used by some binary or lib USED(strncpy)
SIZE() symbol-name get the size in bytes of a symbol SIZE(strncpy)
TYPE() symbol-name get the type in bytes of a symbol TYPE(strncpy)
&& n.a. logical and A && B
|| n.a. logical or A || B
! n.a. not operator !A