scripts: add CONTROL_FLOW to ELF security checks

contrib/devtools/security-check.py

@@ -111,6 +111,17 @@ def check_ELF_separate_code(binary):
                 return False
     return True
 
+def check_ELF_control_flow(binary) -> bool:
+    '''
+    Check for control flow instrumentation
+    '''
+    main = binary.get_function_address('main')
+    content = binary.get_content_from_virtual_address(main, 4, lief.Binary.VA_TYPES.AUTO)
+
+    if content == [243, 15, 30, 250]: # endbr64
+        return True
+    return False
+
 def check_PE_DYNAMIC_BASE(binary) -> bool:
     '''PIE: DllCharacteristics bit 0x40 signifies dynamicbase (ASLR)'''
     return lief.PE.DLL_CHARACTERISTICS.DYNAMIC_BASE in binary.optional_header.dll_characteristics_lists
@@ -210,7 +221,7 @@ BASE_MACHO = [
 
 CHECKS = {
     lief.EXE_FORMATS.ELF: {
-        lief.ARCHITECTURES.X86: BASE_ELF,
+        lief.ARCHITECTURES.X86: BASE_ELF + [('CONTROL_FLOW', check_ELF_control_flow)],
         lief.ARCHITECTURES.ARM: BASE_ELF,
         lief.ARCHITECTURES.ARM64: BASE_ELF,
         lief.ARCHITECTURES.PPC: BASE_ELF,

contrib/devtools/test-security-check.py

@@ -5,6 +5,7 @@
 '''
 Test script for security-check.py
 '''
+import lief #type:ignore
 import os
 import subprocess
 from typing import List
@@ -41,13 +42,37 @@ def call_security_check(cc, source, executable, options):
     p = subprocess.run(['./contrib/devtools/security-check.py',executable], stdout=subprocess.PIPE, universal_newlines=True)
     return (p.returncode, p.stdout.rstrip())
 
+def get_arch(cc, source, executable):
+    subprocess.run([*cc, source, '-o', executable], check=True)
+    binary = lief.parse(executable)
+    arch = binary.abstract.header.architecture
+    os.remove(executable)
+    return arch
+
 class TestSecurityChecks(unittest.TestCase):
     def test_ELF(self):
         source = 'test1.c'
         executable = 'test1'
         cc = determine_wellknown_cmd('CC', 'gcc')
         write_testcode(source)
+        arch = get_arch(cc, source, executable)
 
+        if arch == lief.ARCHITECTURES.X86:
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-zexecstack','-fno-stack-protector','-Wl,-znorelro','-no-pie','-fno-PIE', '-Wl,-z,separate-code']),
+                    (1, executable+': failed PIE NX RELRO Canary CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fno-stack-protector','-Wl,-znorelro','-no-pie','-fno-PIE', '-Wl,-z,separate-code']),
+                    (1, executable+': failed PIE RELRO Canary CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fstack-protector-all','-Wl,-znorelro','-no-pie','-fno-PIE', '-Wl,-z,separate-code']),
+                    (1, executable+': failed PIE RELRO CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fstack-protector-all','-Wl,-znorelro','-pie','-fPIE', '-Wl,-z,separate-code']),
+                    (1, executable+': failed RELRO CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fstack-protector-all','-Wl,-zrelro','-Wl,-z,now','-pie','-fPIE', '-Wl,-z,noseparate-code']),
+                    (1, executable+': failed separate_code CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fstack-protector-all','-Wl,-zrelro','-Wl,-z,now','-pie','-fPIE', '-Wl,-z,separate-code']),
+                    (1, executable+': failed CONTROL_FLOW'))
+            self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fstack-protector-all','-Wl,-zrelro','-Wl,-z,now','-pie','-fPIE', '-Wl,-z,separate-code', '-fcf-protection=full']),
+                    (0, ''))
+        else:
             self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-zexecstack','-fno-stack-protector','-Wl,-znorelro','-no-pie','-fno-PIE', '-Wl,-z,separate-code']),
                     (1, executable+': failed PIE NX RELRO Canary'))
             self.assertEqual(call_security_check(cc, source, executable, ['-Wl,-znoexecstack','-fno-stack-protector','-Wl,-znorelro','-no-pie','-fno-PIE', '-Wl,-z,separate-code']),