LIEF/tests/elf/test_dynamic.py

#!/usr/bin/env python
import unittest
import logging
import os
import sys
import stat
import re
import subprocess
import tempfile
import shutil
import lief
from lief import Logger
Logger.set_level(lief.LOGGING_LEVEL.INFO)

from subprocess import Popen
from unittest import TestCase
from utils import get_sample

CURRENT_DIRECTORY = os.path.dirname(os.path.abspath(__file__))
STUB = lief.parse(os.path.join(CURRENT_DIRECTORY, "hello_lief.bin"))

LIBADD_C = """\
#include <stdlib.h>
#include <stdio.h>

int add(int a, int b);

int add(int a, int b) {
  printf("%d + %d = %d\\n", a, b, a + b);
  return a + b;
}
"""

BINADD_C = """\
#include <stdio.h>
#include <stdlib.h>

int add(int a, int b);

int main(int argc, char **argv) {
  if (argc != 3) {
    printf("Usage: %s <a> <b>\\n", argv[0]);
    exit(-1);
  }

  int res = add(atoi(argv[1]), atoi(argv[2]));
  printf("From myLIb, a + b = %d\\n", res);
  return 0;
}
"""
class LibAddSample(object):
    COUNT = 0
    def __init__(self):
        self.logger = logging.getLogger(__name__)
        self.tmp_dir = tempfile.mkdtemp(suffix='_lief_sample_{:d}'.format(LibAddSample.COUNT))
        self.logger.debug("temp dir: {}".format(self.tmp_dir))

        LibAddSample.COUNT += 1

        self.binadd_path = os.path.join(self.tmp_dir, "binadd.c")
        self.libadd_path = os.path.join(self.tmp_dir, "libadd.c")

        self.libadd_so  = os.path.join(self.tmp_dir, "libadd.so")
        self.binadd_bin = os.path.join(self.tmp_dir, "binadd.bin")

        self.compiler = '/usr/bin/cc'

        if self.compiler is None:
            self.logger.error("Unable to find a compiler")
            sys.exit(0)

        self.logger.debug("Compiler: {}".format(self.compiler))

        with open(self.binadd_path, 'w') as f:
            f.write(BINADD_C)

        with open(self.libadd_path, 'w') as f:
            f.write(LIBADD_C)

        self._compile_libadd()
        self._compile_binadd()


    def _compile_libadd(self, extra_flags=[]):
        if os.path.isfile(self.libadd_so):
            os.remove(self.libadd_so)

        CC_FLAGS = ['-fPIC', '-shared', '-Wl,-soname,libadd.so'] + extra_flags
        cmd = [self.compiler, '-o', self.libadd_so] + CC_FLAGS + [self.libadd_path]
        self.logger.debug("Compile 'libadd' with: {}".format(" ".join(cmd)))

        p = Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

        stdout, _ = p.communicate()

        self.logger.debug(stdout)


    def _compile_binadd(self, extra_flags=[]):
        if os.path.isfile(self.binadd_bin):
            os.remove(self.binadd_bin)

        CC_FLAGS = ['-L', self.tmp_dir] + extra_flags
        cmd = [self.compiler, '-o', self.binadd_bin] + CC_FLAGS + [self.binadd_path, '-ladd']
        self.logger.debug("Compile 'binadd' with: {}".format(" ".join(cmd)))
        p = Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        stdout, _ = p.communicate()
        self.logger.debug(stdout)

    @property
    def libadd(self):
        return self.libadd_so

    @property
    def binadd(self):
        return self.binadd_bin

    @property
    def directory(self):
        return self.tmp_dir

    def remove(self):
        if os.path.isdir(self.directory):
            shutil.rmtree(self.directory)

    def __del__(self):
        self.remove()


class TestDynamic(TestCase):
    def setUp(self):
        self.logger = logging.getLogger(__name__)


    @unittest.skipUnless(sys.platform.startswith("linux"), "requires Linux")
    def test_remove_library(self):
        sample = LibAddSample()
        libadd = lief.parse(sample.libadd)
        binadd = lief.parse(sample.binadd)

        libadd_needed = binadd.get_library("libadd.so")
        binadd -= libadd_needed
        self.assertFalse(binadd.has_library("libadd.so"))


    @unittest.skipUnless(sys.platform.startswith("linux"), "requires Linux")
    def test_remove_tag(self):
        sample = LibAddSample()
        libadd = lief.parse(sample.libadd)
        binadd = lief.parse(sample.binadd)
        self.logger.debug("BEFORE")
        list(map(lambda e : self.logger.debug(e), binadd.dynamic_entries))
        self.logger.debug("")
        binadd -= lief.ELF.DYNAMIC_TAGS.NEEDED

        self.logger.debug("AFTER")
        list(map(lambda e : self.logger.debug(e), binadd.dynamic_entries))
        self.logger.debug("")

        self.assertTrue(all(e.tag != lief.ELF.DYNAMIC_TAGS.NEEDED for e in binadd.dynamic_entries))

    @unittest.skipUnless(sys.platform.startswith("linux"), "requires Linux")
    def test_runpath_api(self):
        sample = LibAddSample()
        libadd = lief.parse(sample.libadd)
        binadd = lief.parse(sample.binadd)

        rpath = lief.ELF.DynamicEntryRunPath()
        rpath = binadd.add(rpath)
        self.logger.debug(rpath)
        rpath += "/tmp"

        self.logger.debug(rpath)

        self.assertEqual(rpath.paths, ["/tmp"])
        self.assertEqual(rpath.runpath, "/tmp")

        rpath.insert(0, "/foo")

        self.assertEqual(rpath.paths, ["/foo", "/tmp"])
        self.assertEqual(rpath.runpath, "/foo:/tmp")

        rpath.paths = ["/foo", "/tmp", "/bar"]

        self.logger.debug(rpath)

        self.assertEqual(rpath.paths, ["/foo", "/tmp", "/bar"])
        self.assertEqual(rpath.runpath, "/foo:/tmp:/bar")

        rpath -= "/tmp"

        self.logger.debug(rpath)

        self.assertEqual(rpath.runpath, "/foo:/bar")

        rpath.remove("/foo").remove("/bar")

        self.logger.debug(rpath)

        self.assertEqual(rpath.runpath, "")

        self.logger.debug(rpath)



    @unittest.skipUnless(sys.platform.startswith("linux"), "requires Linux")
    def test_change_libname(self):
        sample = LibAddSample()
        libadd = lief.parse(sample.libadd)
        binadd = lief.parse(sample.binadd)

        new_name = "libwhichhasalongverylongname.so"


        self.assertIn(lief.ELF.DYNAMIC_TAGS.SONAME, libadd)

        so_name = libadd[lief.ELF.DYNAMIC_TAGS.SONAME]
        self.logger.debug("DT_SONAME: {}".format(so_name.name))
        so_name.name = new_name

        libfoo_path = os.path.join(sample.directory, new_name)
        self.logger.debug(libfoo_path)
        libadd.write(libfoo_path)

        libfoo = lief.parse(libfoo_path)

        new_so_name = libadd[lief.ELF.DYNAMIC_TAGS.SONAME]
        # Check builder did the job right
        self.assertEqual(new_so_name.name, new_name)

        libadd_needed = binadd.get_library("libadd.so")
        libadd_needed.name = new_name

        # Add a RPATH entry
        rpath = lief.ELF.DynamicEntryRunPath(sample.directory)
        rpath = binadd.add(rpath)
        self.logger.debug(rpath)

        new_binadd_path = os.path.join(sample.directory, "binadd_updated.bin")
        self.logger.debug(new_binadd_path)
        binadd.write(new_binadd_path)

        # Remove original binaries:
        os.remove(sample.libadd)
        os.remove(sample.binadd)

        # Run the new executable
        st = os.stat(libfoo_path)
        os.chmod(libfoo_path, st.st_mode | stat.S_IEXEC)

        st = os.stat(new_binadd_path)
        os.chmod(new_binadd_path, st.st_mode | stat.S_IEXEC)

        p = Popen([new_binadd_path, '1', '2'],
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT)
                #env={"LD_LIBRARY_PATH": sample.directory}) # Shouldn't be needed if RPATH inject succeed
        stdout, _ = p.communicate()
        if p.returncode > 0:
            self.logger.fatal(stdout.decode("utf8"))
            self.assertEqual(p.returncode, 0)

        self.logger.debug(stdout.decode("utf8"))
        self.assertIsNotNone(re.search(r'From myLIb, a \+ b = 3', stdout.decode("utf8")))

        sample.remove()



if __name__ == '__main__':

    root_logger = logging.getLogger()
    root_logger.setLevel(logging.DEBUG)

    ch = logging.StreamHandler()
    ch.setLevel(logging.DEBUG)
    root_logger.addHandler(ch)

    unittest.main(verbosity=2)