adding validated services? patching forcad_local.py

ctfcup24-school-ad/sploits/flysim/session_authenticator_codon/build.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+# https://github.com/exaloop/codon
+
+rm -rf build
+rm -rf *.so
+python3 setup.py build_ext --inplace
+rm -rf build
+mv session_authenticator.cpython*.so session_authenticator.so
+echo "Testing"
+python3 -c "import session_authenticator; print(session_authenticator.generate('a', 'bc'))"
+
+# you need only session_authenticator.so file

ctfcup24-school-ad/sploits/flysim/session_authenticator_codon/session_authenticator.codon

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+import time
+def generate_control_key(_id: str, label: str) -> str:
+    msg = _id + label
+    crc = 0xFFFFFFFF
+    polynomial = 0xEDB88320
+    
+    for char in msg:
+        crc ^= ord(char)
+        for _ in range(8):
+            if crc & 1:
+                crc = (crc >> 1) ^ polynomial
+            else:
+                crc >>= 1
+                
+    return hex(crc ^ 0xFFFFFFFF)[2:]
+
+def generate(_id: str, label: str) -> str:
+    return generate_control_key(_id, label)
+
+def verify(_id: str, label: str, control_key: str) -> bool:
+    return generate_control_key(_id, label) == control_key

ctfcup24-school-ad/sploits/flysim/session_authenticator_codon/setup.py

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+# setup.py
+import os
+import sys
+import shutil
+from pathlib import Path
+from setuptools import setup, Extension
+from setuptools.command.build_ext import build_ext
+
+# Find Codon
+codon_path = os.environ.get('CODON_DIR')
+if not codon_path:
+    c = shutil.which('codon')
+    if c:
+        codon_path = Path(c).parent / '..'
+else:
+    codon_path = Path(codon_path)
+for path in [
+    os.path.expanduser('~') + '/.codon',
+    os.getcwd() + '/..',
+]:
+    path = Path(path)
+    if not codon_path and path.exists():
+        codon_path = path
+        break
+
+if (
+    not codon_path
+    or not (codon_path / 'include' / 'codon').exists()
+    or not (codon_path / 'lib' / 'codon').exists()
+):
+    print(
+        'Cannot find Codon.',
+        'Please either install Codon (https://github.com/exaloop/codon),',
+        'or set CODON_DIR if Codon is not in PATH.',
+        file=sys.stderr,
+    )
+    sys.exit(1)
+codon_path = codon_path.resolve()
+print('Found Codon:', str(codon_path))
+
+# Build with Codon
+class CodonExtension(Extension):
+    def __init__(self, name, source):
+        self.source = source
+        super().__init__(name, sources=[], language='c')
+
+class BuildCodonExt(build_ext):
+    def build_extensions(self):
+        pass
+
+    def run(self):
+        inplace, self.inplace = self.inplace, False
+        super().run()
+        for ext in self.extensions:
+            self.build_codon(ext)
+        if inplace:
+            self.copy_extensions_to_source()
+
+    def build_codon(self, ext):
+        extension_path = Path(self.get_ext_fullpath(ext.name))
+        build_dir = Path(self.build_temp)
+        os.makedirs(build_dir, exist_ok=True)
+        os.makedirs(extension_path.parent.absolute(), exist_ok=True)
+
+        codon_cmd = str(codon_path / 'bin' / 'codon')
+        optimization = '-debug' if self.debug else '-release'
+        self.spawn([codon_cmd, 'build', optimization, '--relocation-model=pic', '-pyext',
+                    '-o', str(extension_path) + ".o", '-module', ext.name, ext.source])
+
+        ext.runtime_library_dirs = [str(codon_path / 'lib' / 'codon')]
+        self.compiler.link_shared_object(
+            [str(extension_path) + '.o'],
+            str(extension_path),
+            libraries=['codonrt'],
+            library_dirs=ext.runtime_library_dirs,
+            runtime_library_dirs=ext.runtime_library_dirs,
+            extra_preargs=['-Wl,-rpath,@loader_path'],
+            debug=self.debug,
+            build_temp=self.build_temp,
+        )
+        self.distribution.codon_lib = extension_path
+
+setup(
+    name='session_authenticator',
+    version='0.1',
+    packages=['session_authenticator'],
+    ext_modules=[
+        CodonExtension('session_authenticator', 'session_authenticator.codon'),
+    ],
+    cmdclass={'build_ext': BuildCodonExt}
+)