refactored the cli and forensics codebases as classes and into seperate
folders for readability and consistent API access
This commit is contained in:
@@ -1,6 +1,7 @@
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# src/ctf/analysis.py
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# src/ctf/analysis.py
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# {{{ imports
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# {{{ imports
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import re
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import re
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from abc import ABC, abstractmethod
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from dataclasses import dataclass
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from dataclasses import dataclass
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from pathlib import Path
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from pathlib import Path
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# }}}
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# }}}
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@@ -23,88 +24,132 @@ class AnalysisResult:
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routes: list[RouteResult]
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routes: list[RouteResult]
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# }}}
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# }}}
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# {{{ run_metadata_route
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# {{{ BaseRoute
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def run_metadata_route(file_path: Path) -> RouteResult:
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class BaseRoute(ABC):
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"""Extracts file metadata and scans for potential flags or hints."""
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"""Abstract base class representing an analysis/solver route."""
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from ctf.forensics import get_metadata
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def __init__(self, route_name: str):
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from ctf.decoding import check_for_flag
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self.route_name = route_name
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file_path = Path(file_path).resolve()
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@abstractmethod
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if not file_path.exists():
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def is_applicable(self, file_path: Path) -> bool:
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return RouteResult(
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"""Determines if this route is applicable to the given file."""
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route_name="File Metadata Extraction",
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pass
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executed=True,
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success=False,
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message=f"File not found: {file_path}"
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)
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try:
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@abstractmethod
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meta = get_metadata(file_path)
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def execute(self, file_path: Path) -> RouteResult:
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extracted_flags = []
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"""Executes the analysis route on the target file."""
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pass
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# }}}
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# Scan comment, EXIF attributes, and decoded hints
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# {{{ MetadataRoute
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if meta.comment:
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class MetadataRoute(BaseRoute):
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extracted_flags.extend(check_for_flag(meta.comment))
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"""Route that extracts metadata and parses comments/EXIF for flags."""
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def __init__(self):
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super().__init__("File Metadata Extraction")
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for val in meta.exif_data.values():
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def is_applicable(self, file_path: Path) -> bool:
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if isinstance(val, str):
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# Metadata parsing is applicable to any file
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extracted_flags.extend(check_for_flag(val))
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return True
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for dec_dict in meta.decoded_hints.values():
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def execute(self, file_path: Path) -> RouteResult:
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for dec_val in dec_dict.values():
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from ctf.forensics import get_metadata
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extracted_flags.extend(check_for_flag(dec_val))
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from ctf.decoding import check_for_flag
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extracted_flags = list(set(extracted_flags))
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file_path = Path(file_path).resolve()
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success = True
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if not file_path.exists():
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return RouteResult(
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route_name=self.route_name,
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executed=True,
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success=False,
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message=f"File not found: {file_path}"
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)
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if extracted_flags:
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try:
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msg = f"Metadata inspected. Found {len(extracted_flags)} potential flag(s)."
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meta = get_metadata(file_path)
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else:
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extracted_flags = []
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msg = "Metadata inspected. No obvious flags or decoded hints found."
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details = {
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# Scan comment, EXIF attributes, and decoded hints
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"Filename": meta.filename,
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if meta.comment:
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"Size": f"{meta.size} bytes",
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extracted_flags.extend(check_for_flag(meta.comment))
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"Detected Type": meta.detected_type,
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"Magic": meta.magic,
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"Has EXIF": "Yes" if meta.exif_data else "No",
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"Has Comment": "Yes" if meta.comment else "No",
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"Has Hints": "Yes" if meta.decoded_hints else "No",
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}
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return RouteResult(
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for val in meta.exif_data.values():
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route_name="File Metadata Extraction",
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if isinstance(val, str):
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executed=True,
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extracted_flags.extend(check_for_flag(val))
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success=success,
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message=msg,
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for dec_dict in meta.decoded_hints.values():
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details=details,
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for dec_val in dec_dict.values():
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extracted_flags=extracted_flags
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extracted_flags.extend(check_for_flag(dec_val))
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)
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except Exception as e:
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extracted_flags = list(set(extracted_flags))
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return RouteResult(
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success = True
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route_name="File Metadata Extraction",
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executed=True,
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if extracted_flags:
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success=False,
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msg = f"Metadata inspected. Found {len(extracted_flags)} potential flag(s)."
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message=f"Error extracting metadata: {str(e)}"
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else:
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)
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msg = "Metadata inspected. No obvious flags or decoded hints found."
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details = {
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"Filename": meta.filename,
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"Size": f"{meta.size} bytes",
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"Detected Type": meta.detected_type,
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"Magic": meta.magic,
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"Has EXIF": "Yes" if meta.exif_data else "No",
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"Has Comment": "Yes" if meta.comment else "No",
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"Has Hints": "Yes" if meta.decoded_hints else "No",
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}
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return RouteResult(
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route_name=self.route_name,
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executed=True,
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success=success,
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message=msg,
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details=details,
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extracted_flags=extracted_flags
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)
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except Exception as e:
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return RouteResult(
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route_name=self.route_name,
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executed=True,
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success=False,
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message=f"Error extracting metadata: {str(e)}"
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)
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# }}}
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# {{{ RoutingEngine
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class RoutingEngine:
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"""Manages CTF challenge solvers and dynamic route execution."""
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def __init__(self):
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self.routes: list[BaseRoute] = []
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def register_route(self, route: BaseRoute):
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self.routes.append(route)
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def run_all(self, file_path: Path | None) -> AnalysisResult:
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executed_results = []
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if not file_path:
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# Add a non-executed default result for the metadata route
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executed_results.append(RouteResult(
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route_name="File Metadata Extraction",
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executed=False,
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success=False,
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message="No file attached to analyze."
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))
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return AnalysisResult(success=False, routes=executed_results)
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resolved_path = Path(file_path).resolve()
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for route in self.routes:
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if route.is_applicable(resolved_path):
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executed_results.append(route.execute(resolved_path))
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success = any(r.success and r.extracted_flags for r in executed_results)
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return AnalysisResult(success=success, routes=executed_results)
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# }}}
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# }}}
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# {{{ run_analysis
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# {{{ run_analysis
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def run_analysis(file_path: Path | None = None) -> AnalysisResult:
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def run_analysis(file_path: Path | None = None) -> AnalysisResult:
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"""Executes all registered analysis routes to analyze and solve a challenge."""
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"""Compatibility function that instantiates the RoutingEngine and runs all routes."""
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routes = []
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engine = RoutingEngine()
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engine.register_route(MetadataRoute())
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# Route 1: Metadata Extraction
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return engine.run_all(file_path)
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if file_path:
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routes.append(run_metadata_route(Path(file_path)))
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else:
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routes.append(RouteResult(
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route_name="File Metadata Extraction",
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executed=False,
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success=False,
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message="No file attached to analyze."
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))
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success = any(r.success and r.extracted_flags for r in routes)
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return AnalysisResult(success=success, routes=routes)
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# }}}
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# }}}
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34
src/ctf/cli/__init__.py
Normal file
34
src/ctf/cli/__init__.py
Normal file
@@ -0,0 +1,34 @@
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# src/ctf/cli/__init__.py
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# {{{ imports
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import click
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import sys
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from ctf.cli.basic import basic_group
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from ctf.cli.forensics import forensics_group
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from ctf.cli.steg import steg_group
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from ctf.cli.analyse import analyse_cmd
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from ctf.cli.flag import flag_cmd
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# }}}
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# {{{ debug_exception_handler
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def debug_exception_handler(type, value, tb):
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"""Unhandled exception hook to start post-mortem debugging in pdb."""
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import traceback
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import pdb
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traceback.print_exception(type, value, tb)
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print("\n[!] Unhandled exception. Entering post-mortem debugger...")
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pdb.post_mortem(tb)
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# }}}
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# {{{ cli
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@click.group()
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@click.option("-d", "--debug", is_flag=True, help="Enable post-mortem debugging on errors.")
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def cli(debug):
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if debug:
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sys.excepthook = debug_exception_handler
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cli.add_command(forensics_group)
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cli.add_command(basic_group)
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cli.add_command(flag_cmd)
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cli.add_command(steg_group)
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cli.add_command(analyse_cmd)
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# }}}
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@@ -1,4 +1,4 @@
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# src/ctf/cli_analyse.py
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# src/ctf/cli/analyse.py
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# {{{ imports
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# {{{ imports
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import click
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import click
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from pathlib import Path
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from pathlib import Path
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@@ -1,9 +1,8 @@
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# functions for commands needed
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# src/ctf/cli/basic.py
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# src/commands.py
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# {{{ imports
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# vim foldmethod=marker
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import click
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import click
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from pathlib import Path
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from pathlib import Path
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# }}}
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# {{{ basic_group
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# {{{ basic_group
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# This defines a group with name basic which will nest other comands to be imported in the main loop
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# This defines a group with name basic which will nest other comands to be imported in the main loop
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@@ -37,7 +36,7 @@ def set_flag_format(pattern: str, original: str):
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You can either specify the regex PATTERN directly, or provide an example flag
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You can either specify the regex PATTERN directly, or provide an example flag
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via the -o/--original option to generate and select from a list of suggested patterns.
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via the -o/--original option to generate and select from a list of suggested patterns.
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"""
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"""
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from ctf.config import load_config, write_config
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from ctf.config import Config
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from ctf.utils import suggest_patterns
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from ctf.utils import suggest_patterns
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if pattern is None and original is None:
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if pattern is None and original is None:
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@@ -45,13 +44,12 @@ def set_flag_format(pattern: str, original: str):
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if pattern is not None and original is not None:
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if pattern is not None and original is not None:
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raise click.UsageError("Cannot specify both PATTERN and --original/-o option.")
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raise click.UsageError("Cannot specify both PATTERN and --original/-o option.")
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config_path = "/home/venus/code/ctf/config.toml"
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cfg = Config()
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config = load_config(config_path)
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if "Competition" not in config:
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if "Competition" not in cfg.data:
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config["Competition"] = {}
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cfg.data["Competition"] = {}
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comp_name = config["Competition"].get("competition", "")
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comp_name = cfg.data["Competition"].get("competition", "")
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if original:
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if original:
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if not original.strip():
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if not original.strip():
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@@ -67,8 +65,8 @@ def set_flag_format(pattern: str, original: str):
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val = click.prompt("Select a pattern index", type=click.IntRange(1, len(patterns)))
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val = click.prompt("Select a pattern index", type=click.IntRange(1, len(patterns)))
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pattern = patterns[val - 1]
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pattern = patterns[val - 1]
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config["Competition"]["flag_format"] = pattern
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cfg.data["Competition"]["flag_format"] = pattern
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write_config(config, config_path)
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cfg.save(cfg.data)
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click.echo(f"Flag format set to: {pattern}")
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click.echo(f"Flag format set to: {pattern}")
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# }}}
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# }}}
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@@ -78,16 +76,13 @@ def set_flag_format(pattern: str, original: str):
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@click.argument("name")
|
@click.argument("name")
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def set_competition(name: str):
|
def set_competition(name: str):
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"""Set the name of the active competition."""
|
"""Set the name of the active competition."""
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from ctf.config import load_config, write_config
|
from ctf.config import Config
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|
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config_path = "/home/venus/code/ctf/config.toml"
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cfg = Config()
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config = load_config(config_path)
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|
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if "Competition" not in config:
|
if "Competition" not in cfg.data:
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config["Competition"] = {}
|
cfg.data["Competition"] = {}
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|
cfg.data["Competition"]["competition"] = name
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config["Competition"]["competition"] = name
|
cfg.save(cfg.data)
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write_config(config, config_path)
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click.echo(f"Competition name set to: {name}")
|
click.echo(f"Competition name set to: {name}")
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# }}}
|
# }}}
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|
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47
src/ctf/cli/flag.py
Normal file
47
src/ctf/cli/flag.py
Normal file
@@ -0,0 +1,47 @@
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|
# src/ctf/cli/flag.py
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|
# {{{ imports
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|
import click
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|
from ctf.helpers import detector_state
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|
# }}}
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|
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|
# {{{ flag_cmd
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|
@click.command(name="flag")
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|
@click.option("-p", "--plain", is_flag=True, help="Print raw flag without flavor text.")
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|
@click.option("-l", "--list", "list_format", is_flag=True, help="List the current flag format.")
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|
@click.option("-s", "--set", "set_format", type=str, help="Set the current flag format.")
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|
@click.pass_context
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|
def flag_cmd(ctx, plain, list_format, set_format):
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|
"""Retrieve the last detected flag from config, or list/set flag format options."""
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|
from ctf.config import Config
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|
if list_format:
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|
cfg = Config()
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|
flag_format = cfg.data.get("Competition", {}).get("flag_format", "")
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|
if plain:
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|
click.echo(flag_format)
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|
else:
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|
click.echo(f"Current flag format: {flag_format}" if flag_format else "No flag format configured.")
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|
return
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|
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|
if set_format is not None:
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|
from ctf.commands import set_flag_format
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|
ctx.invoke(set_flag_format, pattern=set_format, original=None)
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|
return
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|
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|
# TODO add support for multiple flags and flag selection
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|
if detector_state["active"] is not None:
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|
detector_state["active"].detecting = False
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|
try:
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|
cfg = Config()
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|
last_flag = cfg.data.get("Competition", {}).get("last_flag", "")
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|
if not last_flag:
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|
if not plain:
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|
click.echo("No flag has been detected yet.")
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|
return
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|
if plain:
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|
click.echo(last_flag)
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|
else:
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|
click.echo(f"Last detected flag: {last_flag}")
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|
finally:
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|
if detector_state["active"] is not None:
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|
detector_state["active"].detecting = True
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|
# }}}
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@@ -1,10 +1,9 @@
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# src/ctf/cli_forensics.py
|
# src/ctf/cli/forensics.py
|
||||||
# CLI wrapper and rendering layer for forensics commands
|
# {{{ imports
|
||||||
|
|
||||||
# vim foldmethod=marker
|
|
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import click
|
import click
|
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from pathlib import Path
|
from pathlib import Path
|
||||||
from ctf.forensics import get_metadata, COMMON_SIGNATURES
|
from ctf.forensics import get_metadata, COMMON_SIGNATURES
|
||||||
|
# }}}
|
||||||
|
|
||||||
# {{{ forensics_group
|
# {{{ forensics_group
|
||||||
@click.group(name="forensics")
|
@click.group(name="forensics")
|
||||||
@@ -140,4 +139,3 @@ def list_signatures():
|
|||||||
|
|
||||||
console.print(table)
|
console.print(table)
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
@@ -1,4 +1,4 @@
|
|||||||
# src/ctf/cli_steg.py
|
# src/ctf/cli/steg.py
|
||||||
# {{{ imports
|
# {{{ imports
|
||||||
import click
|
import click
|
||||||
from pathlib import Path
|
from pathlib import Path
|
||||||
@@ -1,30 +0,0 @@
|
|||||||
# src/ctf/cli_helpers.py
|
|
||||||
# {{{ imports
|
|
||||||
import click
|
|
||||||
from ctf.helpers import detector_state
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ flag_cmd
|
|
||||||
@click.command(name="flag")
|
|
||||||
@click.option("-p", "--plain", is_flag=True, help="Print raw flag without flavor text.")
|
|
||||||
def flag_cmd(plain):
|
|
||||||
"""Retrieve the last detected flag from config."""
|
|
||||||
# TODO add support for multiple flags and flag selection
|
|
||||||
if detector_state["active"] is not None:
|
|
||||||
detector_state["active"].detecting = False
|
|
||||||
try:
|
|
||||||
from ctf.config import load_config
|
|
||||||
config = load_config("/home/venus/code/ctf/config.toml")
|
|
||||||
last_flag = config.get("Competition", {}).get("last_flag", "")
|
|
||||||
if not last_flag:
|
|
||||||
if not plain:
|
|
||||||
click.echo("No flag has been detected yet.")
|
|
||||||
return
|
|
||||||
if plain:
|
|
||||||
click.echo(last_flag)
|
|
||||||
else:
|
|
||||||
click.echo(f"Last detected flag: {last_flag}")
|
|
||||||
finally:
|
|
||||||
if detector_state["active"] is not None:
|
|
||||||
detector_state["active"].detecting = True
|
|
||||||
# }}}
|
|
||||||
@@ -1,26 +1,38 @@
|
|||||||
# src/ctf/config.py
|
# src/ctf/config.py
|
||||||
# {{{ imports
|
# {{{ imports
|
||||||
import toml
|
import toml
|
||||||
|
import os
|
||||||
from pathlib import Path
|
from pathlib import Path
|
||||||
from platformdirs import user_config_dir
|
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ load_config
|
# {{{ Config
|
||||||
def load_config(config = f"{user_config_dir()}/ctf-config.toml") -> dict:
|
class Config:
|
||||||
p = Path(config)
|
"""Manages CTF challenge configuration loading and persistence."""
|
||||||
if p.exists():
|
def __init__(self, path: str | Path | None = None):
|
||||||
return toml.load(p)
|
if path is None:
|
||||||
return {}
|
# Check environment variable first, then fallback to hardcoded path
|
||||||
# }}}
|
path = os.environ.get("CTF_CONFIG_PATH", "/home/venus/code/ctf/config.toml")
|
||||||
|
self.path = Path(path)
|
||||||
|
self.data = self._load()
|
||||||
|
|
||||||
# {{{ write_config
|
def _load(self) -> dict:
|
||||||
def write_config(data: dict, config = f"{user_config_dir()}/ctf"):
|
if self.path.exists():
|
||||||
with open(config, "w") as f:
|
try:
|
||||||
toml.dump(data, f)
|
return toml.load(self.path)
|
||||||
|
except Exception:
|
||||||
|
return {}
|
||||||
|
return {}
|
||||||
|
|
||||||
|
def save(self, data: dict):
|
||||||
|
self.data = data
|
||||||
|
self.path.parent.mkdir(parents=True, exist_ok=True)
|
||||||
|
with open(self.path, "w") as f:
|
||||||
|
toml.dump(self.data, f)
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ exports
|
# {{{ exports
|
||||||
config_data = load_config("/home/venus/code/ctf/config.toml")
|
# Load config instance to expose default values
|
||||||
competition = config_data.get("Competition", {})
|
_cfg = Config()
|
||||||
enviroment = config_data.get("Enviroment", {})
|
competition = _cfg.data.get("Competition", {})
|
||||||
|
enviroment = _cfg.data.get("Enviroment", {})
|
||||||
# }}}
|
# }}}
|
||||||
|
|||||||
@@ -1,80 +1,152 @@
|
|||||||
# src/ctf/decoding.py
|
# src/ctf/decoding.py
|
||||||
|
# {{{ imports
|
||||||
|
from abc import ABC, abstractmethod
|
||||||
from chepy import Chepy
|
from chepy import Chepy
|
||||||
import re
|
import re
|
||||||
from typing import Dict, Set
|
from typing import Dict, Set, List
|
||||||
from ctf.helpers import check_for_flag, is_valid_flag
|
from ctf.helpers import check_for_flag, is_valid_flag
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ attempt_decode
|
# {{{ BaseDecoder
|
||||||
def attempt_decode(val: str, name: str, pattern: str, method_name: str, len_check=None, validator=None) -> str | None:
|
class BaseDecoder(ABC):
|
||||||
"""Helper to run regex matching, dynamic Chepy decoding, and string printability checks."""
|
"""Abstract base class representing a Chepy-based metadata decoder."""
|
||||||
# Find all matches sequentially and try decoding
|
def __init__(self, name: str, pattern: str, method_name: str):
|
||||||
for match in re.finditer(pattern, val):
|
self.name = name
|
||||||
matched_val = match.group(0)
|
self.pattern = pattern
|
||||||
if len_check and not len_check(matched_val):
|
self.method_name = method_name
|
||||||
continue
|
|
||||||
|
|
||||||
try:
|
def is_applicable(self, matched_val: str) -> bool:
|
||||||
chepy_inst = Chepy(matched_val)
|
"""Determines if the matched substring is applicable for decoding (e.g. length checks)."""
|
||||||
method = getattr(chepy_inst, method_name)
|
return True
|
||||||
decoded = method().state
|
|
||||||
if isinstance(decoded, bytes):
|
|
||||||
dec_str = decoded.decode("utf-8")
|
|
||||||
elif isinstance(decoded, str):
|
|
||||||
dec_str = decoded
|
|
||||||
else:
|
|
||||||
dec_str = ""
|
|
||||||
|
|
||||||
if dec_str.strip() and all(32 <= ord(c) < 127 or c in "\r\n\t" for c in dec_str):
|
def validate(self, decoded_str: str, original_str: str) -> bool:
|
||||||
if validator and not validator(dec_str, val):
|
"""Validates if the decoded string is expected/correct (e.g. flag regex checks)."""
|
||||||
continue
|
return True
|
||||||
return dec_str
|
|
||||||
except Exception:
|
def attempt_single(self, val: str) -> str | None:
|
||||||
pass
|
"""Searches val for matches and returns the first successfully decoded printable string."""
|
||||||
return None
|
for match in re.finditer(self.pattern, val):
|
||||||
|
matched_val = match.group(0)
|
||||||
|
if not self.is_applicable(matched_val):
|
||||||
|
continue
|
||||||
|
|
||||||
|
try:
|
||||||
|
chepy_inst = Chepy(matched_val)
|
||||||
|
method = getattr(chepy_inst, self.method_name)
|
||||||
|
decoded = method().state
|
||||||
|
if isinstance(decoded, bytes):
|
||||||
|
dec_str = decoded.decode("utf-8")
|
||||||
|
elif isinstance(decoded, str):
|
||||||
|
dec_str = decoded
|
||||||
|
else:
|
||||||
|
dec_str = ""
|
||||||
|
|
||||||
|
if dec_str.strip() and all(32 <= ord(c) < 127 or c in "\r\n\t" for c in dec_str):
|
||||||
|
if not self.validate(dec_str, val):
|
||||||
|
continue
|
||||||
|
return dec_str
|
||||||
|
except Exception:
|
||||||
|
pass
|
||||||
|
return None
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ Concrete Decoders
|
||||||
|
class HexDecoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("hex", r"[0-9a-fA-F]{4,}", "from_hex")
|
||||||
|
def is_applicable(self, matched_val: str) -> bool:
|
||||||
|
return len(matched_val) % 2 == 0
|
||||||
|
|
||||||
|
class Base64Decoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("base64", r"[A-Za-z0-9+/=]{4,}", "from_base64")
|
||||||
|
def is_applicable(self, matched_val: str) -> bool:
|
||||||
|
return len(matched_val) % 4 == 0
|
||||||
|
|
||||||
|
class Base32Decoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("base32", r"[A-Za-z2-7=]{4,}", "from_base32")
|
||||||
|
def is_applicable(self, matched_val: str) -> bool:
|
||||||
|
return len(matched_val) % 8 == 0
|
||||||
|
|
||||||
|
class BinaryDecoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("binary", r"[01]{8,}", "from_binary")
|
||||||
|
def is_applicable(self, matched_val: str) -> bool:
|
||||||
|
return len(matched_val) % 8 == 0
|
||||||
|
|
||||||
|
class UrlDecoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("url", r"(?:%[0-9a-fA-F]{2})+", "from_url_encoding")
|
||||||
|
|
||||||
|
class Rot13Decoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("rot13", r"[\x20-\x7E\s]{4,}", "rot_13")
|
||||||
|
def validate(self, decoded_str: str, original_str: str) -> bool:
|
||||||
|
return is_valid_flag(decoded_str, original_str)
|
||||||
|
|
||||||
|
class ReversedDecoder(BaseDecoder):
|
||||||
|
def __init__(self):
|
||||||
|
super().__init__("reversed", r"[\x20-\x7E\s]{4,}", "reverse")
|
||||||
|
def validate(self, decoded_str: str, original_str: str) -> bool:
|
||||||
|
return is_valid_flag(decoded_str, original_str)
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ DecodingRegistry
|
||||||
|
class DecodingRegistry:
|
||||||
|
"""Orchestrates decoding metadata using registered BaseDecoder classes."""
|
||||||
|
def __init__(self):
|
||||||
|
self.decoders: List[BaseDecoder] = []
|
||||||
|
|
||||||
|
def register_decoder(self, decoder: BaseDecoder):
|
||||||
|
self.decoders.append(decoder)
|
||||||
|
|
||||||
|
def try_decode(self, val: str, current_chain: str = "", max_depth: int = 10, seen: Set[str] = None) -> Dict[str, str]:
|
||||||
|
if seen is None:
|
||||||
|
seen = set()
|
||||||
|
|
||||||
|
results = {}
|
||||||
|
if not isinstance(val, str) or not val.strip() or max_depth <= 0:
|
||||||
|
return results
|
||||||
|
|
||||||
|
cleaned_val = val.strip()
|
||||||
|
if cleaned_val in seen:
|
||||||
|
return results
|
||||||
|
seen.add(cleaned_val)
|
||||||
|
|
||||||
|
for decoder in self.decoders:
|
||||||
|
decoded_val = decoder.attempt_single(cleaned_val)
|
||||||
|
if decoded_val is not None:
|
||||||
|
chain_name = f"{current_chain}->{decoder.name}" if current_chain else decoder.name
|
||||||
|
results[chain_name] = decoded_val
|
||||||
|
|
||||||
|
# Recurse
|
||||||
|
nested_results = self.try_decode(
|
||||||
|
decoded_val,
|
||||||
|
current_chain=chain_name,
|
||||||
|
max_depth=max_depth - 1,
|
||||||
|
seen=set(seen)
|
||||||
|
)
|
||||||
|
results.update(nested_results)
|
||||||
|
|
||||||
|
return results
|
||||||
|
|
||||||
|
@classmethod
|
||||||
|
def get_default_registry(cls) -> "DecodingRegistry":
|
||||||
|
registry = cls()
|
||||||
|
registry.register_decoder(HexDecoder())
|
||||||
|
registry.register_decoder(Base64Decoder())
|
||||||
|
registry.register_decoder(Base32Decoder())
|
||||||
|
registry.register_decoder(BinaryDecoder())
|
||||||
|
registry.register_decoder(UrlDecoder())
|
||||||
|
registry.register_decoder(Rot13Decoder())
|
||||||
|
registry.register_decoder(ReversedDecoder())
|
||||||
|
return registry
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ try_decode_metadata
|
# {{{ try_decode_metadata
|
||||||
def try_decode_metadata(val: str, current_chain: str = "", max_depth: int = 10, seen: Set[str] = None) -> Dict[str, str]:
|
def try_decode_metadata(val: str, current_chain: str = "", max_depth: int = 10, seen: Set[str] = None) -> Dict[str, str]:
|
||||||
"""Attempts to decode a metadata value using defined formats recursively."""
|
"""Compatibility wrapper that routes decoding requests to the default registry."""
|
||||||
if seen is None:
|
registry = DecodingRegistry.get_default_registry()
|
||||||
seen = set()
|
return registry.try_decode(val, current_chain, max_depth, seen)
|
||||||
|
|
||||||
results = {}
|
|
||||||
if not isinstance(val, str) or not val.strip() or max_depth <= 0:
|
|
||||||
return results
|
|
||||||
|
|
||||||
cleaned_val = val.strip()
|
|
||||||
if cleaned_val in seen:
|
|
||||||
return results
|
|
||||||
seen.add(cleaned_val)
|
|
||||||
|
|
||||||
# We define our decoders here using unanchored patterns. Note: for rot13 and reversed, we only allow them
|
|
||||||
# if they produce a valid flag to avoid spamming everyday metadata fields.
|
|
||||||
formats = [
|
|
||||||
("hex", r"[0-9a-fA-F]{4,}", "from_hex", lambda s: len(s) % 2 == 0, None),
|
|
||||||
("base64", r"[A-Za-z0-9+/=]{4,}", "from_base64", lambda s: len(s) % 4 == 0, None),
|
|
||||||
("base32", r"[A-Za-z2-7=]{4,}", "from_base32", lambda s: len(s) % 8 == 0, None),
|
|
||||||
("binary", r"[01]{8,}", "from_binary", lambda s: len(s) % 8 == 0, None),
|
|
||||||
("url", r"(?:%[0-9a-fA-F]{2})+", "from_url_encoding", None, None),
|
|
||||||
("rot13", r"[\x20-\x7E\s]{4,}", "rot_13", None, is_valid_flag),
|
|
||||||
("reversed", r"[\x20-\x7E\s]{4,}", "reverse", None, is_valid_flag),
|
|
||||||
]
|
|
||||||
|
|
||||||
for name, pattern, method, len_check, validator in formats:
|
|
||||||
decoded_val = attempt_decode(cleaned_val, name, pattern, method, len_check, validator)
|
|
||||||
if decoded_val is not None:
|
|
||||||
chain_name = f"{current_chain}->{name}" if current_chain else name
|
|
||||||
results[chain_name] = decoded_val
|
|
||||||
|
|
||||||
# Recurse with copy of seen to allow different branching paths to process same strings
|
|
||||||
nested_results = try_decode_metadata(
|
|
||||||
decoded_val,
|
|
||||||
current_chain=chain_name,
|
|
||||||
max_depth=max_depth - 1,
|
|
||||||
seen=set(seen)
|
|
||||||
)
|
|
||||||
results.update(nested_results)
|
|
||||||
|
|
||||||
return results
|
|
||||||
# }}}
|
# }}}
|
||||||
|
|||||||
32
src/ctf/forensics/__init__.py
Normal file
32
src/ctf/forensics/__init__.py
Normal file
@@ -0,0 +1,32 @@
|
|||||||
|
# src/ctf/forensics/__init__.py
|
||||||
|
# {{{ imports
|
||||||
|
from ctf.forensics.base import FileMetadata, FormatParser, ParserFactory, FallbackParser, COMMON_SIGNATURES
|
||||||
|
from ctf.forensics.jpeg import JpegParser
|
||||||
|
from ctf.forensics.png import PngParser
|
||||||
|
from ctf.forensics.gif import GifParser
|
||||||
|
from ctf.forensics.metadata import get_metadata
|
||||||
|
from pathlib import Path
|
||||||
|
from typing import Dict, Any
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ get_exif
|
||||||
|
def get_exif(path: Path) -> Dict[str, Any]:
|
||||||
|
"""Compatibility wrapper for extracting EXIF tags."""
|
||||||
|
try:
|
||||||
|
with open(path, "rb") as f:
|
||||||
|
data = f.read()
|
||||||
|
return ParserFactory.get_parser(data).get_exif_tags(data)
|
||||||
|
except Exception:
|
||||||
|
return {}
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ get_comment
|
||||||
|
def get_comment(path: Path) -> str:
|
||||||
|
"""Compatibility wrapper for extracting comments."""
|
||||||
|
try:
|
||||||
|
with open(path, "rb") as f:
|
||||||
|
data = f.read()
|
||||||
|
return ParserFactory.get_parser(data).get_comment(data)
|
||||||
|
except Exception:
|
||||||
|
return ""
|
||||||
|
# }}}
|
||||||
114
src/ctf/forensics/base.py
Normal file
114
src/ctf/forensics/base.py
Normal file
@@ -0,0 +1,114 @@
|
|||||||
|
# src/ctf/forensics/base.py
|
||||||
|
# {{{ imports
|
||||||
|
from abc import ABC, abstractmethod
|
||||||
|
from dataclasses import dataclass, field
|
||||||
|
from typing import Dict, Any
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ Common Signatures
|
||||||
|
COMMON_SIGNATURES = {
|
||||||
|
b"\x89PNG\r\n\x1a\n": ("PNG Image", [".png"]),
|
||||||
|
b"\xff\xd8\xff": ("JPEG Image", [".jpg", ".jpeg"]),
|
||||||
|
b"%PDF": ("PDF Document", [".pdf"]),
|
||||||
|
b"PK\x03\x04": ("ZIP Archive", [".zip"]),
|
||||||
|
b"\x7fELF": ("ELF Executable", [".elf"]),
|
||||||
|
b"MZ": ("PE Executable", [".exe", ".dll"]),
|
||||||
|
b"GIF87a": ("GIF Image", [".gif"]),
|
||||||
|
b"GIF89a": ("GIF Image", [".gif"]),
|
||||||
|
b"7z\xbc\xaf\x27\x1c": ("7-Zip Archive", [".7z"]),
|
||||||
|
b"\x1f\x8b": ("GZIP Archive", [".gz"]),
|
||||||
|
b"Rar!\x1a\x07\x00": ("RAR Archive", [".rar"]),
|
||||||
|
b"Rar!\x1a\x07\x01\x00": ("RAR Archive", [".rar"]),
|
||||||
|
b"BZh": ("BZIP2 Archive", [".bz2"]),
|
||||||
|
b"BM": ("BMP Image", [".bmp"]),
|
||||||
|
b"ID3": ("MP3 Audio", [".mp3"]),
|
||||||
|
}
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ FileMetadata
|
||||||
|
@dataclass
|
||||||
|
class FileMetadata:
|
||||||
|
filename: str
|
||||||
|
size: int
|
||||||
|
magic: str
|
||||||
|
extension: str
|
||||||
|
detected_type: str
|
||||||
|
|
||||||
|
# POSIX Permissions
|
||||||
|
permissions_octal: str
|
||||||
|
permissions_symbolic: str
|
||||||
|
|
||||||
|
# Ownership Identity
|
||||||
|
owner_uid: int
|
||||||
|
owner_username: str
|
||||||
|
owner_gid: int
|
||||||
|
owner_groupname: str
|
||||||
|
|
||||||
|
# Allocation Metrics
|
||||||
|
allocated_size: int
|
||||||
|
|
||||||
|
# Hard Links
|
||||||
|
hard_links: int
|
||||||
|
|
||||||
|
# Inode & Device Identifiers
|
||||||
|
inode: int
|
||||||
|
device: int
|
||||||
|
|
||||||
|
# Extended Attributes
|
||||||
|
extended_attributes: Dict[str, str] = field(default_factory=dict)
|
||||||
|
|
||||||
|
# EXIF Data
|
||||||
|
exif_data: Dict[str, Any] = field(default_factory=dict)
|
||||||
|
|
||||||
|
# Physical Image Data
|
||||||
|
physical_data: Dict[str, Any] = field(default_factory=dict)
|
||||||
|
|
||||||
|
# Decoded metadata hints
|
||||||
|
decoded_hints: Dict[str, Dict[str, str]] = field(default_factory=dict)
|
||||||
|
|
||||||
|
# JPEG/PNG Comments
|
||||||
|
comment: str = ""
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ FormatParser
|
||||||
|
class FormatParser(ABC):
|
||||||
|
"""Abstract base class representing a file format metadata parser."""
|
||||||
|
@abstractmethod
|
||||||
|
def is_matching(self, data: bytes) -> bool:
|
||||||
|
pass
|
||||||
|
@abstractmethod
|
||||||
|
def parse_physical(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
pass
|
||||||
|
@abstractmethod
|
||||||
|
def get_comment(self, data: bytes) -> str:
|
||||||
|
pass
|
||||||
|
@abstractmethod
|
||||||
|
def get_exif_tags(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
pass
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ FallbackParser
|
||||||
|
class FallbackParser(FormatParser):
|
||||||
|
def is_matching(self, data: bytes) -> bool:
|
||||||
|
return True
|
||||||
|
def parse_physical(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
return {}
|
||||||
|
def get_comment(self, data: bytes) -> str:
|
||||||
|
return ""
|
||||||
|
def get_exif_tags(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
return {}
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ ParserFactory
|
||||||
|
class ParserFactory:
|
||||||
|
@staticmethod
|
||||||
|
def get_parser(data: bytes) -> FormatParser:
|
||||||
|
from ctf.forensics.jpeg import JpegParser
|
||||||
|
from ctf.forensics.png import PngParser
|
||||||
|
from ctf.forensics.gif import GifParser
|
||||||
|
parsers = [JpegParser(), PngParser(), GifParser()]
|
||||||
|
for parser in parsers:
|
||||||
|
if parser.is_matching(data):
|
||||||
|
return parser
|
||||||
|
return FallbackParser()
|
||||||
|
# }}}
|
||||||
98
src/ctf/forensics/gif.py
Normal file
98
src/ctf/forensics/gif.py
Normal file
@@ -0,0 +1,98 @@
|
|||||||
|
# src/ctf/forensics/gif.py
|
||||||
|
# {{{ imports
|
||||||
|
import struct
|
||||||
|
from typing import Dict, Any
|
||||||
|
from ctf.forensics.base import FormatParser
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ GifParser
|
||||||
|
class GifParser(FormatParser):
|
||||||
|
def is_matching(self, data: bytes) -> bool:
|
||||||
|
return data.startswith(b"GIF87a") or data.startswith(b"GIF89a")
|
||||||
|
def parse_physical(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
return get_gif_physical(data)
|
||||||
|
def get_comment(self, data: bytes) -> str:
|
||||||
|
return extract_gif_comments(data)
|
||||||
|
def get_exif_tags(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
return {}
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ get_gif_physical
|
||||||
|
def get_gif_physical(data: bytes) -> Dict[str, Any]:
|
||||||
|
"""Parses GIF logical screen descriptor for physical size."""
|
||||||
|
physical = {}
|
||||||
|
if not (data.startswith(b"GIF87a") or data.startswith(b"GIF89a")):
|
||||||
|
return physical
|
||||||
|
if len(data) >= 10:
|
||||||
|
width = struct.unpack("<H", data[6:8])[0]
|
||||||
|
height = struct.unpack("<H", data[8:10])[0]
|
||||||
|
physical["Image Size"] = f"{width}x{height}"
|
||||||
|
mp = (width * height) / 1000000.0
|
||||||
|
physical["Megapixels"] = f"{mp:.1f}"
|
||||||
|
physical["Encoding Process"] = "LZW"
|
||||||
|
return physical
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ extract_gif_comments
|
||||||
|
def extract_gif_comments(data: bytes) -> str:
|
||||||
|
"""Extracts comments from GIF comment extensions (\x21\xfe) sequentially."""
|
||||||
|
if not (data.startswith(b"GIF87a") or data.startswith(b"GIF89a")):
|
||||||
|
return ""
|
||||||
|
comments = []
|
||||||
|
idx = 6
|
||||||
|
if idx + 7 > len(data):
|
||||||
|
return ""
|
||||||
|
packed_byte = data[idx+4]
|
||||||
|
global_color_table_present = bool(packed_byte & 0x80)
|
||||||
|
global_color_table_size = 2 ** ((packed_byte & 0x07) + 1)
|
||||||
|
idx += 7
|
||||||
|
if global_color_table_present:
|
||||||
|
idx += 3 * global_color_table_size
|
||||||
|
|
||||||
|
while idx < len(data) - 2:
|
||||||
|
intro = data[idx]
|
||||||
|
if intro == 0x21: # Extension Introducer
|
||||||
|
ext_label = data[idx+1]
|
||||||
|
idx += 2
|
||||||
|
if ext_label == 0xfe: # Comment Extension
|
||||||
|
comment_parts = []
|
||||||
|
while idx < len(data):
|
||||||
|
block_len = data[idx]
|
||||||
|
idx += 1
|
||||||
|
if block_len == 0:
|
||||||
|
break
|
||||||
|
if idx + block_len <= len(data):
|
||||||
|
comment_parts.append(data[idx:idx+block_len].decode("utf-8", errors="ignore"))
|
||||||
|
idx += block_len
|
||||||
|
else:
|
||||||
|
break
|
||||||
|
comments.append("".join(comment_parts))
|
||||||
|
else:
|
||||||
|
while idx < len(data):
|
||||||
|
block_len = data[idx]
|
||||||
|
idx += 1
|
||||||
|
if block_len == 0:
|
||||||
|
break
|
||||||
|
idx += block_len
|
||||||
|
elif intro == 0x2c: # Image Descriptor
|
||||||
|
if idx + 10 > len(data):
|
||||||
|
break
|
||||||
|
packed = data[idx+9]
|
||||||
|
local_table = bool(packed & 0x80)
|
||||||
|
local_table_size = 2 ** ((packed & 0x07) + 1)
|
||||||
|
idx += 10
|
||||||
|
if local_table:
|
||||||
|
idx += 3 * local_table_size
|
||||||
|
idx += 1
|
||||||
|
while idx < len(data):
|
||||||
|
block_len = data[idx]
|
||||||
|
idx += 1
|
||||||
|
if block_len == 0:
|
||||||
|
break
|
||||||
|
idx += block_len
|
||||||
|
elif intro == 0x3b: # Trailer
|
||||||
|
break
|
||||||
|
else:
|
||||||
|
idx += 1
|
||||||
|
return "\n".join(comments)
|
||||||
|
# }}}
|
||||||
@@ -1,225 +1,35 @@
|
|||||||
# src/ctf/forensics.py
|
# src/ctf/forensics/jpeg.py
|
||||||
# Library for forensic analysis (pure functions only)
|
# {{{ imports
|
||||||
|
|
||||||
# vim foldmethod=marker
|
|
||||||
from dataclasses import dataclass, field
|
|
||||||
from pathlib import Path
|
|
||||||
import stat
|
|
||||||
import os
|
|
||||||
import sys
|
|
||||||
import struct
|
import struct
|
||||||
import xml.etree.ElementTree as ET
|
import xml.etree.ElementTree as ET
|
||||||
from typing import List, Dict, Any
|
from typing import Dict, Any
|
||||||
|
from ctf.forensics.base import FormatParser
|
||||||
try:
|
|
||||||
import pwd
|
|
||||||
import grp
|
|
||||||
except ImportError:
|
|
||||||
pwd = None
|
|
||||||
grp = None
|
|
||||||
|
|
||||||
# {{{ Common Signatures
|
|
||||||
COMMON_SIGNATURES = {
|
|
||||||
b"\x89PNG\r\n\x1a\n": ("PNG Image", [".png"]),
|
|
||||||
b"\xff\xd8\xff": ("JPEG Image", [".jpg", ".jpeg"]),
|
|
||||||
b"%PDF": ("PDF Document", [".pdf"]),
|
|
||||||
b"PK\x03\x04": ("ZIP Archive", [".zip"]),
|
|
||||||
b"\x7fELF": ("ELF Executable", [".elf"]),
|
|
||||||
b"MZ": ("PE Executable", [".exe", ".dll"]),
|
|
||||||
b"GIF87a": ("GIF Image", [".gif"]),
|
|
||||||
b"GIF89a": ("GIF Image", [".gif"]),
|
|
||||||
b"7z\xbc\xaf\x27\x1c": ("7-Zip Archive", [".7z"]),
|
|
||||||
b"\x1f\x8b": ("GZIP Archive", [".gz"]),
|
|
||||||
b"Rar!\x1a\x07\x00": ("RAR Archive", [".rar"]),
|
|
||||||
b"Rar!\x1a\x07\x01\x00": ("RAR Archive", [".rar"]),
|
|
||||||
b"BZh": ("BZIP2 Archive", [".bz2"]),
|
|
||||||
b"BM": ("BMP Image", [".bmp"]),
|
|
||||||
b"ID3": ("MP3 Audio", [".mp3"]),
|
|
||||||
}
|
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ FileMetadata
|
# {{{ JpegParser
|
||||||
@dataclass
|
class JpegParser(FormatParser):
|
||||||
class FileMetadata:
|
def is_matching(self, data: bytes) -> bool:
|
||||||
filename: str
|
return data.startswith(b"\xff\xd8\xff")
|
||||||
size: int
|
def parse_physical(self, data: bytes) -> Dict[str, Any]:
|
||||||
magic: str
|
return get_jpeg_physical(data)
|
||||||
extension: str
|
def get_comment(self, data: bytes) -> str:
|
||||||
detected_type: str
|
return extract_jpeg_comment(data)
|
||||||
|
def get_exif_tags(self, data: bytes) -> Dict[str, Any]:
|
||||||
# Task 1: POSIX Permissions
|
tags = {}
|
||||||
permissions_octal: str
|
exif_data = extract_jpeg_exif(data)
|
||||||
permissions_symbolic: str
|
if exif_data:
|
||||||
|
try:
|
||||||
# Task 2: Ownership Identity
|
tags.update(parse_tiff(exif_data))
|
||||||
owner_uid: int
|
except Exception: pass
|
||||||
owner_username: str
|
xmp_str = extract_jpeg_xmp(data)
|
||||||
owner_gid: int
|
if xmp_str:
|
||||||
owner_groupname: str
|
try:
|
||||||
|
tags.update(parse_xmp(xmp_str))
|
||||||
# Task 3: Allocation Metrics
|
except Exception: pass
|
||||||
allocated_size: int
|
|
||||||
|
|
||||||
# Task 4: Hard Links
|
|
||||||
hard_links: int
|
|
||||||
|
|
||||||
# Task 5: Inode & Device Identifiers
|
|
||||||
inode: int
|
|
||||||
device: int
|
|
||||||
|
|
||||||
# Task 6: Extended Attributes
|
|
||||||
extended_attributes: Dict[str, str] = field(default_factory=dict)
|
|
||||||
|
|
||||||
# EXIF Data
|
|
||||||
exif_data: Dict[str, Any] = field(default_factory=dict)
|
|
||||||
|
|
||||||
# Physical Image Data
|
|
||||||
physical_data: Dict[str, Any] = field(default_factory=dict)
|
|
||||||
|
|
||||||
# Decoded metadata hints
|
|
||||||
decoded_hints: Dict[str, Dict[str, str]] = field(default_factory=dict)
|
|
||||||
|
|
||||||
# JPEG/PNG Comments
|
|
||||||
comment: str = ""
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ get_metadata
|
|
||||||
def get_metadata(path: Path) -> FileMetadata:
|
|
||||||
"""Extracts metadata attributes from a file without any console rendering."""
|
|
||||||
p = Path(path)
|
|
||||||
if not p.exists():
|
|
||||||
raise FileNotFoundError(f"File not found: {p}")
|
|
||||||
|
|
||||||
stat_info = p.stat()
|
|
||||||
|
|
||||||
# Apparent size & extension
|
|
||||||
size = stat_info.st_size
|
|
||||||
extension = p.suffix
|
|
||||||
|
|
||||||
# Magic bytes
|
|
||||||
try:
|
|
||||||
with open(p, 'rb') as f:
|
|
||||||
magic = f.read(8).hex().upper()
|
|
||||||
except Exception:
|
|
||||||
magic = ""
|
|
||||||
|
|
||||||
detected_type = "Unknown"
|
|
||||||
try:
|
|
||||||
magic_bytes = bytes.fromhex(magic)
|
|
||||||
for signature, (type_name, exts) in COMMON_SIGNATURES.items():
|
|
||||||
if magic_bytes.startswith(signature):
|
|
||||||
detected_type = type_name
|
|
||||||
break
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
# POSIX Permissions
|
|
||||||
mode = stat_info.st_mode
|
|
||||||
permissions_octal = oct(stat.S_IMODE(mode))
|
|
||||||
permissions_symbolic = stat.filemode(mode)
|
|
||||||
|
|
||||||
# Ownership Identity
|
|
||||||
owner_uid = stat_info.st_uid
|
|
||||||
owner_gid = stat_info.st_gid
|
|
||||||
owner_username = str(owner_uid)
|
|
||||||
owner_groupname = str(owner_gid)
|
|
||||||
|
|
||||||
if pwd is not None:
|
|
||||||
try:
|
try:
|
||||||
owner_username = pwd.getpwuid(owner_uid).pw_name
|
tags.update(extract_jpeg_iptc(data))
|
||||||
except KeyError:
|
except Exception: pass
|
||||||
pass
|
return tags
|
||||||
if grp is not None:
|
|
||||||
try:
|
|
||||||
owner_groupname = grp.getgrgid(owner_gid).gr_name
|
|
||||||
except KeyError:
|
|
||||||
pass
|
|
||||||
|
|
||||||
# Allocation Metrics
|
|
||||||
if hasattr(stat_info, "st_blocks"):
|
|
||||||
allocated_size = stat_info.st_blocks * 512
|
|
||||||
else:
|
|
||||||
allocated_size = size
|
|
||||||
|
|
||||||
# Hard Links
|
|
||||||
hard_links = stat_info.st_nlink
|
|
||||||
|
|
||||||
# Inode & Device Identifiers
|
|
||||||
inode = stat_info.st_ino
|
|
||||||
device = stat_info.st_dev
|
|
||||||
|
|
||||||
# Extended Attributes
|
|
||||||
extended_attributes = {}
|
|
||||||
if hasattr(os, "listxattr") and hasattr(os, "getxattr"):
|
|
||||||
try:
|
|
||||||
attrs = os.listxattr(p)
|
|
||||||
for attr in attrs:
|
|
||||||
try:
|
|
||||||
val = os.getxattr(p, attr)
|
|
||||||
extended_attributes[attr] = val.decode("utf-8", errors="ignore")
|
|
||||||
except OSError:
|
|
||||||
pass
|
|
||||||
except OSError:
|
|
||||||
pass
|
|
||||||
|
|
||||||
exif_data = get_exif(p)
|
|
||||||
comment = get_comment(p)
|
|
||||||
|
|
||||||
physical_data = {}
|
|
||||||
try:
|
|
||||||
with open(p, "rb") as f:
|
|
||||||
file_bytes = f.read()
|
|
||||||
if file_bytes.startswith(b"\xff\xd8\xff"):
|
|
||||||
physical_data = get_jpeg_physical(file_bytes)
|
|
||||||
elif file_bytes.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
physical_data = get_png_physical(file_bytes)
|
|
||||||
elif file_bytes.startswith(b"GIF87a") or file_bytes.startswith(b"GIF89a"):
|
|
||||||
physical_data = get_gif_physical(file_bytes)
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
decoded_hints = {}
|
|
||||||
try:
|
|
||||||
from ctf.decoding import try_decode_metadata
|
|
||||||
if comment:
|
|
||||||
dec = try_decode_metadata(comment)
|
|
||||||
if dec:
|
|
||||||
decoded_hints["Comment"] = dec
|
|
||||||
for tag, val in exif_data.items():
|
|
||||||
if isinstance(val, str):
|
|
||||||
dec = try_decode_metadata(val)
|
|
||||||
if dec:
|
|
||||||
decoded_hints[f"EXIF:{tag}"] = dec
|
|
||||||
for attr, val in extended_attributes.items():
|
|
||||||
if isinstance(val, str):
|
|
||||||
dec = try_decode_metadata(val)
|
|
||||||
if dec:
|
|
||||||
decoded_hints[f"xattr:{attr}"] = dec
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
return FileMetadata(
|
|
||||||
filename=p.name,
|
|
||||||
size=size,
|
|
||||||
magic=magic,
|
|
||||||
extension=extension,
|
|
||||||
detected_type=detected_type,
|
|
||||||
permissions_octal=permissions_octal,
|
|
||||||
permissions_symbolic=permissions_symbolic,
|
|
||||||
owner_uid=owner_uid,
|
|
||||||
owner_username=owner_username,
|
|
||||||
owner_gid=owner_gid,
|
|
||||||
owner_groupname=owner_groupname,
|
|
||||||
allocated_size=allocated_size,
|
|
||||||
hard_links=hard_links,
|
|
||||||
inode=inode,
|
|
||||||
device=device,
|
|
||||||
extended_attributes=extended_attributes,
|
|
||||||
exif_data=exif_data,
|
|
||||||
physical_data=physical_data,
|
|
||||||
decoded_hints=decoded_hints,
|
|
||||||
comment=comment
|
|
||||||
)
|
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ EXIF tags
|
# {{{ EXIF tags
|
||||||
@@ -260,7 +70,8 @@ EXIF_TAGS = {
|
|||||||
0xa403: "WhiteBalance",
|
0xa403: "WhiteBalance",
|
||||||
0xa405: "FocalLengthIn35mmFilm",
|
0xa405: "FocalLengthIn35mmFilm",
|
||||||
0xa406: "SceneCaptureType",
|
0xa406: "SceneCaptureType",
|
||||||
}# }}}
|
}
|
||||||
|
# }}}
|
||||||
|
|
||||||
# {{{ parse_tiff
|
# {{{ parse_tiff
|
||||||
def parse_tiff(data: bytes) -> Dict[str, Any]:
|
def parse_tiff(data: bytes) -> Dict[str, Any]:
|
||||||
@@ -371,7 +182,6 @@ def extract_jpeg_exif(data: bytes) -> bytes:
|
|||||||
marker = data[idx+1]
|
marker = data[idx+1]
|
||||||
if marker == 0xd9: # EOI
|
if marker == 0xd9: # EOI
|
||||||
break
|
break
|
||||||
# Markers without length parameters
|
|
||||||
if marker in (0xd8, 0xd9, 0x00) or 0xd0 <= marker <= 0xd7:
|
if marker in (0xd8, 0xd9, 0x00) or 0xd0 <= marker <= 0xd7:
|
||||||
idx += 2
|
idx += 2
|
||||||
continue
|
continue
|
||||||
@@ -386,75 +196,6 @@ def extract_jpeg_exif(data: bytes) -> bytes:
|
|||||||
return b""
|
return b""
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ extract_png_exif
|
|
||||||
def extract_png_exif(data: bytes) -> bytes:
|
|
||||||
"""Extracts raw Exif/TIFF payload from PNG eXIf chunks."""
|
|
||||||
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
return b""
|
|
||||||
idx = 8
|
|
||||||
while idx < len(data) - 8:
|
|
||||||
length = struct.unpack(">I", data[idx:idx+4])[0]
|
|
||||||
chunk_type = data[idx+4:idx+8]
|
|
||||||
if chunk_type == b"eXIf":
|
|
||||||
return data[idx+8:idx+8+length]
|
|
||||||
elif chunk_type == b"IEND":
|
|
||||||
break
|
|
||||||
idx += 12 + length
|
|
||||||
return b""
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ get_exif
|
|
||||||
def get_exif(path: Path) -> Dict[str, Any]:
|
|
||||||
"""Reads file, extracts Exif and XMP segments, and parses them to a tag dictionary."""
|
|
||||||
try:
|
|
||||||
with open(path, "rb") as f:
|
|
||||||
data = f.read()
|
|
||||||
except Exception:
|
|
||||||
return {}
|
|
||||||
|
|
||||||
tags = {}
|
|
||||||
|
|
||||||
# 1. Parse standard EXIF
|
|
||||||
exif_data = b""
|
|
||||||
if data.startswith(b"\xff\xd8\xff"):
|
|
||||||
exif_data = extract_jpeg_exif(data)
|
|
||||||
elif data.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
exif_data = extract_png_exif(data)
|
|
||||||
|
|
||||||
if exif_data:
|
|
||||||
try:
|
|
||||||
tags.update(parse_tiff(exif_data))
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
# 2. Parse XMP (Adobe)
|
|
||||||
xmp_str = ""
|
|
||||||
if data.startswith(b"\xff\xd8\xff"):
|
|
||||||
xmp_str = extract_jpeg_xmp(data)
|
|
||||||
|
|
||||||
if xmp_str:
|
|
||||||
try:
|
|
||||||
tags.update(parse_xmp(xmp_str))
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
# 3. Parse IPTC (Photoshop APP13) if JPEG
|
|
||||||
if data.startswith(b"\xff\xd8\xff"):
|
|
||||||
try:
|
|
||||||
tags.update(extract_jpeg_iptc(data))
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
# 4. Parse PNG text chunks if PNG
|
|
||||||
if data.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
try:
|
|
||||||
tags.update(parse_png_text_chunks(data))
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
|
|
||||||
return tags
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ extract_jpeg_comment
|
# {{{ extract_jpeg_comment
|
||||||
def extract_jpeg_comment(data: bytes) -> str:
|
def extract_jpeg_comment(data: bytes) -> str:
|
||||||
"""Extracts raw comment string from JPEG COM (0xfe) segments."""
|
"""Extracts raw comment string from JPEG COM (0xfe) segments."""
|
||||||
@@ -479,23 +220,7 @@ def extract_jpeg_comment(data: bytes) -> str:
|
|||||||
return ""
|
return ""
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ get_comment
|
# {{{ NS_map
|
||||||
def get_comment(path: Path) -> str:
|
|
||||||
"""Reads file, checks headers, and extracts JPEG COM / GIF comments."""
|
|
||||||
try:
|
|
||||||
with open(path, "rb") as f:
|
|
||||||
data = f.read()
|
|
||||||
except Exception:
|
|
||||||
return ""
|
|
||||||
|
|
||||||
if data.startswith(b"\xff\xd8\xff"):
|
|
||||||
return extract_jpeg_comment(data)
|
|
||||||
elif data.startswith(b"GIF87a") or data.startswith(b"GIF89a"):
|
|
||||||
return extract_gif_comments(data)
|
|
||||||
return ""
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
#{{{ NS_map
|
|
||||||
NS_MAP = {
|
NS_MAP = {
|
||||||
"http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
|
"http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
|
||||||
"http://creativecommons.org/ns#": "cc",
|
"http://creativecommons.org/ns#": "cc",
|
||||||
@@ -504,7 +229,7 @@ NS_MAP = {
|
|||||||
"http://ns.adobe.com/exif/1.0/": "exif",
|
"http://ns.adobe.com/exif/1.0/": "exif",
|
||||||
"http://ns.adobe.com/tiff/1.0/": "tiff",
|
"http://ns.adobe.com/tiff/1.0/": "tiff",
|
||||||
}
|
}
|
||||||
#}}}
|
# }}}
|
||||||
|
|
||||||
# {{{ parse_xmp
|
# {{{ parse_xmp
|
||||||
def parse_xmp(xmp_str: str) -> Dict[str, Any]:
|
def parse_xmp(xmp_str: str) -> Dict[str, Any]:
|
||||||
@@ -654,84 +379,6 @@ def get_jpeg_physical(data: bytes) -> Dict[str, Any]:
|
|||||||
return physical
|
return physical
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ get_png_physical
|
|
||||||
def get_png_physical(data: bytes) -> Dict[str, Any]:
|
|
||||||
"""Parses PNG IHDR and pHYs chunks for physical properties."""
|
|
||||||
physical = {}
|
|
||||||
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
return physical
|
|
||||||
|
|
||||||
idx = 8
|
|
||||||
while idx < len(data) - 8:
|
|
||||||
length = struct.unpack(">I", data[idx:idx+4])[0]
|
|
||||||
chunk_type = data[idx+4:idx+8]
|
|
||||||
chunk_data = data[idx+8:idx+8+length]
|
|
||||||
|
|
||||||
if chunk_type == b"IHDR":
|
|
||||||
if len(chunk_data) >= 13:
|
|
||||||
width = struct.unpack(">I", chunk_data[0:4])[0]
|
|
||||||
height = struct.unpack(">I", chunk_data[4:8])[0]
|
|
||||||
bit_depth = chunk_data[8]
|
|
||||||
color_type = chunk_data[9]
|
|
||||||
compression = chunk_data[10]
|
|
||||||
filter_method = chunk_data[11]
|
|
||||||
interlace = chunk_data[12]
|
|
||||||
|
|
||||||
physical["Image Size"] = f"{width}x{height}"
|
|
||||||
mp = (width * height) / 1000000.0
|
|
||||||
physical["Megapixels"] = f"{mp:.1f}"
|
|
||||||
physical["Bit Depth"] = f"{bit_depth} bits/sample"
|
|
||||||
|
|
||||||
color_types = {
|
|
||||||
0: "Grayscale",
|
|
||||||
2: "Truecolor",
|
|
||||||
3: "Indexed-color",
|
|
||||||
4: "Grayscale with Alpha",
|
|
||||||
6: "Truecolor with Alpha"
|
|
||||||
}
|
|
||||||
physical["Color Type"] = color_types.get(color_type, f"Unknown ({color_type})")
|
|
||||||
|
|
||||||
if compression == 0:
|
|
||||||
physical["Encoding Process"] = "Deflate/Inflate"
|
|
||||||
else:
|
|
||||||
physical["Encoding Process"] = f"Unknown compression ({compression})"
|
|
||||||
|
|
||||||
interlace_methods = {
|
|
||||||
0: "Noninterlaced",
|
|
||||||
1: "Adam7 Interlace"
|
|
||||||
}
|
|
||||||
physical["Interlace Method"] = interlace_methods.get(interlace, f"Unknown ({interlace})")
|
|
||||||
elif chunk_type == b"pHYs":
|
|
||||||
if len(chunk_data) >= 9:
|
|
||||||
x_res = struct.unpack(">I", chunk_data[0:4])[0]
|
|
||||||
y_res = struct.unpack(">I", chunk_data[4:8])[0]
|
|
||||||
unit = chunk_data[8]
|
|
||||||
unit_str = " meters" if unit == 1 else " (unknown unit)"
|
|
||||||
physical["Pixels Per Unit X"] = f"{x_res}{unit_str}"
|
|
||||||
physical["Pixels Per Unit Y"] = f"{y_res}{unit_str}"
|
|
||||||
elif chunk_type == b"IEND":
|
|
||||||
break
|
|
||||||
idx += 12 + length
|
|
||||||
|
|
||||||
return physical
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ get_gif_physical
|
|
||||||
def get_gif_physical(data: bytes) -> Dict[str, Any]:
|
|
||||||
"""Parses GIF logical screen descriptor for physical size."""
|
|
||||||
physical = {}
|
|
||||||
if not (data.startswith(b"GIF87a") or data.startswith(b"GIF89a")):
|
|
||||||
return physical
|
|
||||||
if len(data) >= 10:
|
|
||||||
width = struct.unpack("<H", data[6:8])[0]
|
|
||||||
height = struct.unpack("<H", data[8:10])[0]
|
|
||||||
physical["Image Size"] = f"{width}x{height}"
|
|
||||||
mp = (width * height) / 1000000.0
|
|
||||||
physical["Megapixels"] = f"{mp:.1f}"
|
|
||||||
physical["Encoding Process"] = "LZW"
|
|
||||||
return physical
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ extract_jpeg_iptc
|
# {{{ extract_jpeg_iptc
|
||||||
def extract_jpeg_iptc(data: bytes) -> Dict[str, str]:
|
def extract_jpeg_iptc(data: bytes) -> Dict[str, str]:
|
||||||
"""Extracts IPTC/NAA metadata (Record 2) from Photoshop APP13 segments."""
|
"""Extracts IPTC/NAA metadata (Record 2) from Photoshop APP13 segments."""
|
||||||
@@ -819,132 +466,3 @@ def extract_jpeg_iptc(data: bytes) -> Dict[str, str]:
|
|||||||
|
|
||||||
return iptc_metadata
|
return iptc_metadata
|
||||||
# }}}
|
# }}}
|
||||||
|
|
||||||
# {{{ parse_png_text_chunks
|
|
||||||
def parse_png_text_chunks(data: bytes) -> Dict[str, str]:
|
|
||||||
"""Decompresses and extracts standard tEXt/zTXt/iTXt PNG text metadata."""
|
|
||||||
import zlib
|
|
||||||
text_metadata = {}
|
|
||||||
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
|
||||||
return text_metadata
|
|
||||||
idx = 8
|
|
||||||
while idx < len(data) - 8:
|
|
||||||
length = struct.unpack(">I", data[idx:idx+4])[0]
|
|
||||||
chunk_type = data[idx+4:idx+8]
|
|
||||||
chunk_data = data[idx+8:idx+8+length]
|
|
||||||
if chunk_type == b"tEXt":
|
|
||||||
parts = chunk_data.split(b"\x00", 1)
|
|
||||||
if len(parts) == 2:
|
|
||||||
key = parts[0].decode("utf-8", errors="ignore")
|
|
||||||
val = parts[1].decode("utf-8", errors="ignore")
|
|
||||||
text_metadata[key] = val
|
|
||||||
elif chunk_type == b"zTXt":
|
|
||||||
parts = chunk_data.split(b"\x00", 1)
|
|
||||||
if len(parts) == 2:
|
|
||||||
key = parts[0].decode("utf-8", errors="ignore")
|
|
||||||
remaining = parts[1]
|
|
||||||
if len(remaining) > 1:
|
|
||||||
comp_method = remaining[0]
|
|
||||||
comp_text = remaining[1:]
|
|
||||||
if comp_method == 0:
|
|
||||||
try:
|
|
||||||
val = zlib.decompress(comp_text).decode("utf-8", errors="ignore")
|
|
||||||
text_metadata[key] = val
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
elif chunk_type == b"iTXt":
|
|
||||||
parts = chunk_data.split(b"\x00", 1)
|
|
||||||
if len(parts) == 2:
|
|
||||||
key = parts[0].decode("utf-8", errors="ignore")
|
|
||||||
remaining = parts[1]
|
|
||||||
if len(remaining) >= 2:
|
|
||||||
comp_flag = remaining[0]
|
|
||||||
comp_method = remaining[1]
|
|
||||||
rem = remaining[2:]
|
|
||||||
parts2 = rem.split(b"\x00", 1)
|
|
||||||
if len(parts2) == 2:
|
|
||||||
lang_tag = parts2[0].decode("utf-8", errors="ignore")
|
|
||||||
rem = parts2[1]
|
|
||||||
parts3 = rem.split(b"\x00", 1)
|
|
||||||
if len(parts3) == 2:
|
|
||||||
trans_key = parts3[0].decode("utf-8", errors="ignore")
|
|
||||||
text_bytes = parts3[1]
|
|
||||||
if comp_flag == 1 and comp_method == 0:
|
|
||||||
try:
|
|
||||||
val = zlib.decompress(text_bytes).decode("utf-8", errors="ignore")
|
|
||||||
text_metadata[key] = val
|
|
||||||
except Exception:
|
|
||||||
pass
|
|
||||||
else:
|
|
||||||
val = text_bytes.decode("utf-8", errors="ignore")
|
|
||||||
text_metadata[key] = val
|
|
||||||
elif chunk_type == b"IEND":
|
|
||||||
break
|
|
||||||
idx += 12 + length
|
|
||||||
return text_metadata
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ extract_gif_comments
|
|
||||||
def extract_gif_comments(data: bytes) -> str:
|
|
||||||
"""Extracts comments from GIF comment extensions (\x21\xfe) sequentially."""
|
|
||||||
if not (data.startswith(b"GIF87a") or data.startswith(b"GIF89a")):
|
|
||||||
return ""
|
|
||||||
comments = []
|
|
||||||
idx = 6
|
|
||||||
if idx + 7 > len(data):
|
|
||||||
return ""
|
|
||||||
packed_byte = data[idx+4]
|
|
||||||
global_color_table_present = bool(packed_byte & 0x80)
|
|
||||||
global_color_table_size = 2 ** ((packed_byte & 0x07) + 1)
|
|
||||||
idx += 7
|
|
||||||
if global_color_table_present:
|
|
||||||
idx += 3 * global_color_table_size
|
|
||||||
|
|
||||||
while idx < len(data) - 2:
|
|
||||||
intro = data[idx]
|
|
||||||
if intro == 0x21: # Extension Introducer
|
|
||||||
ext_label = data[idx+1]
|
|
||||||
idx += 2
|
|
||||||
if ext_label == 0xfe: # Comment Extension
|
|
||||||
comment_parts = []
|
|
||||||
while idx < len(data):
|
|
||||||
block_len = data[idx]
|
|
||||||
idx += 1
|
|
||||||
if block_len == 0:
|
|
||||||
break
|
|
||||||
if idx + block_len <= len(data):
|
|
||||||
comment_parts.append(data[idx:idx+block_len].decode("utf-8", errors="ignore"))
|
|
||||||
idx += block_len
|
|
||||||
else:
|
|
||||||
break
|
|
||||||
comments.append("".join(comment_parts))
|
|
||||||
else:
|
|
||||||
while idx < len(data):
|
|
||||||
block_len = data[idx]
|
|
||||||
idx += 1
|
|
||||||
if block_len == 0:
|
|
||||||
break
|
|
||||||
idx += block_len
|
|
||||||
elif intro == 0x2c: # Image Descriptor
|
|
||||||
if idx + 10 > len(data):
|
|
||||||
break
|
|
||||||
packed = data[idx+9]
|
|
||||||
local_table = bool(packed & 0x80)
|
|
||||||
local_table_size = 2 ** ((packed & 0x07) + 1)
|
|
||||||
idx += 10
|
|
||||||
if local_table:
|
|
||||||
idx += 3 * local_table_size
|
|
||||||
idx += 1
|
|
||||||
while idx < len(data):
|
|
||||||
block_len = data[idx]
|
|
||||||
idx += 1
|
|
||||||
if block_len == 0:
|
|
||||||
break
|
|
||||||
idx += block_len
|
|
||||||
elif intro == 0x3b: # Trailer
|
|
||||||
break
|
|
||||||
else:
|
|
||||||
idx += 1
|
|
||||||
return "\n".join(comments)
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
139
src/ctf/forensics/metadata.py
Normal file
139
src/ctf/forensics/metadata.py
Normal file
@@ -0,0 +1,139 @@
|
|||||||
|
# src/ctf/forensics/metadata.py
|
||||||
|
# {{{ imports
|
||||||
|
from pathlib import Path
|
||||||
|
import os
|
||||||
|
import stat
|
||||||
|
from ctf.forensics.base import FileMetadata, COMMON_SIGNATURES, ParserFactory
|
||||||
|
|
||||||
|
try:
|
||||||
|
import pwd
|
||||||
|
import grp
|
||||||
|
except ImportError:
|
||||||
|
pwd = None
|
||||||
|
grp = None
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ get_metadata
|
||||||
|
def get_metadata(path: Path) -> FileMetadata:
|
||||||
|
"""Extracts metadata attributes from a file without any console rendering."""
|
||||||
|
p = Path(path)
|
||||||
|
if not p.exists():
|
||||||
|
raise FileNotFoundError(f"File not found: {p}")
|
||||||
|
|
||||||
|
stat_info = p.stat()
|
||||||
|
size = stat_info.st_size
|
||||||
|
extension = p.suffix
|
||||||
|
|
||||||
|
try:
|
||||||
|
with open(p, 'rb') as f:
|
||||||
|
magic = f.read(8).hex().upper()
|
||||||
|
except Exception:
|
||||||
|
magic = ""
|
||||||
|
|
||||||
|
detected_type = "Unknown"
|
||||||
|
try:
|
||||||
|
magic_bytes = bytes.fromhex(magic)
|
||||||
|
for signature, (type_name, exts) in COMMON_SIGNATURES.items():
|
||||||
|
if magic_bytes.startswith(signature):
|
||||||
|
detected_type = type_name
|
||||||
|
break
|
||||||
|
except Exception:
|
||||||
|
pass
|
||||||
|
|
||||||
|
mode = stat_info.st_mode
|
||||||
|
permissions_octal = oct(stat.S_IMODE(mode))
|
||||||
|
permissions_symbolic = stat.filemode(mode)
|
||||||
|
|
||||||
|
owner_uid = stat_info.st_uid
|
||||||
|
owner_gid = stat_info.st_gid
|
||||||
|
owner_username = str(owner_uid)
|
||||||
|
owner_groupname = str(owner_gid)
|
||||||
|
|
||||||
|
if pwd is not None:
|
||||||
|
try:
|
||||||
|
owner_username = pwd.getpwuid(owner_uid).pw_name
|
||||||
|
except KeyError:
|
||||||
|
pass
|
||||||
|
if grp is not None:
|
||||||
|
try:
|
||||||
|
owner_groupname = grp.getgrgid(owner_gid).gr_name
|
||||||
|
except KeyError:
|
||||||
|
pass
|
||||||
|
|
||||||
|
if hasattr(stat_info, "st_blocks"):
|
||||||
|
allocated_size = stat_info.st_blocks * 512
|
||||||
|
else:
|
||||||
|
allocated_size = size
|
||||||
|
|
||||||
|
hard_links = stat_info.st_nlink
|
||||||
|
inode = stat_info.st_ino
|
||||||
|
device = stat_info.st_dev
|
||||||
|
|
||||||
|
extended_attributes = {}
|
||||||
|
if hasattr(os, "listxattr") and hasattr(os, "getxattr"):
|
||||||
|
try:
|
||||||
|
attrs = os.listxattr(p)
|
||||||
|
for attr in attrs:
|
||||||
|
try:
|
||||||
|
val = os.getxattr(p, attr)
|
||||||
|
extended_attributes[attr] = val.decode("utf-8", errors="ignore")
|
||||||
|
except OSError:
|
||||||
|
pass
|
||||||
|
except OSError:
|
||||||
|
pass
|
||||||
|
|
||||||
|
try:
|
||||||
|
with open(p, "rb") as f:
|
||||||
|
file_bytes = f.read()
|
||||||
|
parser = ParserFactory.get_parser(file_bytes)
|
||||||
|
exif_data = parser.get_exif_tags(file_bytes)
|
||||||
|
comment = parser.get_comment(file_bytes)
|
||||||
|
physical_data = parser.parse_physical(file_bytes)
|
||||||
|
except Exception:
|
||||||
|
exif_data = {}
|
||||||
|
comment = ""
|
||||||
|
physical_data = {}
|
||||||
|
|
||||||
|
decoded_hints = {}
|
||||||
|
try:
|
||||||
|
from ctf.decoding import try_decode_metadata
|
||||||
|
if comment:
|
||||||
|
dec = try_decode_metadata(comment)
|
||||||
|
if dec:
|
||||||
|
decoded_hints["Comment"] = dec
|
||||||
|
for tag, val in exif_data.items():
|
||||||
|
if isinstance(val, str):
|
||||||
|
dec = try_decode_metadata(val)
|
||||||
|
if dec:
|
||||||
|
decoded_hints[f"EXIF:{tag}"] = dec
|
||||||
|
for attr, val in extended_attributes.items():
|
||||||
|
if isinstance(val, str):
|
||||||
|
dec = try_decode_metadata(val)
|
||||||
|
if dec:
|
||||||
|
decoded_hints[f"xattr:{attr}"] = dec
|
||||||
|
except Exception:
|
||||||
|
pass
|
||||||
|
|
||||||
|
return FileMetadata(
|
||||||
|
filename=p.name,
|
||||||
|
size=size,
|
||||||
|
magic=magic,
|
||||||
|
extension=extension,
|
||||||
|
detected_type=detected_type,
|
||||||
|
permissions_octal=permissions_octal,
|
||||||
|
permissions_symbolic=permissions_symbolic,
|
||||||
|
owner_uid=owner_uid,
|
||||||
|
owner_username=owner_username,
|
||||||
|
owner_gid=owner_gid,
|
||||||
|
owner_groupname=owner_groupname,
|
||||||
|
allocated_size=allocated_size,
|
||||||
|
hard_links=hard_links,
|
||||||
|
inode=inode,
|
||||||
|
device=device,
|
||||||
|
extended_attributes=extended_attributes,
|
||||||
|
exif_data=exif_data,
|
||||||
|
physical_data=physical_data,
|
||||||
|
decoded_hints=decoded_hints,
|
||||||
|
comment=comment
|
||||||
|
)
|
||||||
|
# }}}
|
||||||
171
src/ctf/forensics/png.py
Normal file
171
src/ctf/forensics/png.py
Normal file
@@ -0,0 +1,171 @@
|
|||||||
|
# src/ctf/forensics/png.py
|
||||||
|
# {{{ imports
|
||||||
|
import struct
|
||||||
|
from typing import Dict, Any
|
||||||
|
from ctf.forensics.base import FormatParser
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ PngParser
|
||||||
|
class PngParser(FormatParser):
|
||||||
|
def is_matching(self, data: bytes) -> bool:
|
||||||
|
return data.startswith(b"\x89PNG\r\n\x1a\n")
|
||||||
|
def parse_physical(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
return get_png_physical(data)
|
||||||
|
def get_comment(self, data: bytes) -> str:
|
||||||
|
return ""
|
||||||
|
def get_exif_tags(self, data: bytes) -> Dict[str, Any]:
|
||||||
|
tags = {}
|
||||||
|
exif_data = extract_png_exif(data)
|
||||||
|
if exif_data:
|
||||||
|
try:
|
||||||
|
from ctf.forensics.jpeg import parse_tiff
|
||||||
|
tags.update(parse_tiff(exif_data))
|
||||||
|
except Exception: pass
|
||||||
|
try:
|
||||||
|
tags.update(parse_png_text_chunks(data))
|
||||||
|
except Exception: pass
|
||||||
|
return tags
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ extract_png_exif
|
||||||
|
def extract_png_exif(data: bytes) -> bytes:
|
||||||
|
"""Extracts raw Exif/TIFF payload from PNG eXIf chunks."""
|
||||||
|
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
||||||
|
return b""
|
||||||
|
idx = 8
|
||||||
|
while idx < len(data) - 8:
|
||||||
|
length = struct.unpack(">I", data[idx:idx+4])[0]
|
||||||
|
chunk_type = data[idx+4:idx+8]
|
||||||
|
if chunk_type == b"eXIf":
|
||||||
|
return data[idx+8:idx+8+length]
|
||||||
|
elif chunk_type == b"IEND":
|
||||||
|
break
|
||||||
|
idx += 12 + length
|
||||||
|
return b""
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ get_png_physical
|
||||||
|
def get_png_physical(data: bytes) -> Dict[str, Any]:
|
||||||
|
"""Parses PNG IHDR and pHYs chunks for physical properties."""
|
||||||
|
physical = {}
|
||||||
|
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
||||||
|
return physical
|
||||||
|
|
||||||
|
idx = 8
|
||||||
|
while idx < len(data) - 8:
|
||||||
|
length = struct.unpack(">I", data[idx:idx+4])[0]
|
||||||
|
chunk_type = data[idx+4:idx+8]
|
||||||
|
chunk_data = data[idx+8:idx+8+length]
|
||||||
|
|
||||||
|
if chunk_type == b"IHDR":
|
||||||
|
if len(chunk_data) >= 13:
|
||||||
|
width = struct.unpack(">I", chunk_data[0:4])[0]
|
||||||
|
height = struct.unpack(">I", chunk_data[4:8])[0]
|
||||||
|
bit_depth = chunk_data[8]
|
||||||
|
color_type = chunk_data[9]
|
||||||
|
compression = chunk_data[10]
|
||||||
|
filter_method = chunk_data[11]
|
||||||
|
interlace = chunk_data[12]
|
||||||
|
|
||||||
|
physical["Image Size"] = f"{width}x{height}"
|
||||||
|
mp = (width * height) / 1000000.0
|
||||||
|
physical["Megapixels"] = f"{mp:.1f}"
|
||||||
|
physical["Bit Depth"] = f"{bit_depth} bits/sample"
|
||||||
|
|
||||||
|
color_types = {
|
||||||
|
0: "Grayscale",
|
||||||
|
2: "Truecolor",
|
||||||
|
3: "Indexed-color",
|
||||||
|
4: "Grayscale with Alpha",
|
||||||
|
6: "Truecolor with Alpha"
|
||||||
|
}
|
||||||
|
physical["Color Type"] = color_types.get(color_type, f"Unknown ({color_type})")
|
||||||
|
|
||||||
|
if compression == 0:
|
||||||
|
physical["Encoding Process"] = "Deflate/Inflate"
|
||||||
|
else:
|
||||||
|
physical["Encoding Process"] = f"Unknown compression ({compression})"
|
||||||
|
|
||||||
|
interlace_methods = {
|
||||||
|
0: "Noninterlaced",
|
||||||
|
1: "Adam7 Interlace"
|
||||||
|
}
|
||||||
|
physical["Interlace Method"] = interlace_methods.get(interlace, f"Unknown ({interlace})")
|
||||||
|
elif chunk_type == b"pHYs":
|
||||||
|
if len(chunk_data) >= 9:
|
||||||
|
x_res = struct.unpack(">I", chunk_data[0:4])[0]
|
||||||
|
y_res = struct.unpack(">I", chunk_data[4:8])[0]
|
||||||
|
unit = chunk_data[8]
|
||||||
|
unit_str = " meters" if unit == 1 else " (unknown unit)"
|
||||||
|
physical["Pixels Per Unit X"] = f"{x_res}{unit_str}"
|
||||||
|
physical["Pixels Per Unit Y"] = f"{y_res}{unit_str}"
|
||||||
|
elif chunk_type == b"IEND":
|
||||||
|
break
|
||||||
|
idx += 12 + length
|
||||||
|
|
||||||
|
return physical
|
||||||
|
# }}}
|
||||||
|
|
||||||
|
# {{{ parse_png_text_chunks
|
||||||
|
def parse_png_text_chunks(data: bytes) -> Dict[str, str]:
|
||||||
|
"""Decompresses and extracts standard tEXt/zTXt/iTXt PNG text metadata."""
|
||||||
|
import zlib
|
||||||
|
text_metadata = {}
|
||||||
|
if not data.startswith(b"\x89PNG\r\n\x1a\n"):
|
||||||
|
return text_metadata
|
||||||
|
idx = 8
|
||||||
|
while idx < len(data) - 8:
|
||||||
|
length = struct.unpack(">I", data[idx:idx+4])[0]
|
||||||
|
chunk_type = data[idx+4:idx+8]
|
||||||
|
chunk_data = data[idx+8:idx+8+length]
|
||||||
|
if chunk_type == b"tEXt":
|
||||||
|
parts = chunk_data.split(b"\x00", 1)
|
||||||
|
if len(parts) == 2:
|
||||||
|
key = parts[0].decode("utf-8", errors="ignore")
|
||||||
|
val = parts[1].decode("utf-8", errors="ignore")
|
||||||
|
text_metadata[key] = val
|
||||||
|
elif chunk_type == b"zTXt":
|
||||||
|
parts = chunk_data.split(b"\x00", 1)
|
||||||
|
if len(parts) == 2:
|
||||||
|
key = parts[0].decode("utf-8", errors="ignore")
|
||||||
|
remaining = parts[1]
|
||||||
|
if len(remaining) > 1:
|
||||||
|
comp_method = remaining[0]
|
||||||
|
comp_text = remaining[1:]
|
||||||
|
if comp_method == 0:
|
||||||
|
try:
|
||||||
|
val = zlib.decompress(comp_text).decode("utf-8", errors="ignore")
|
||||||
|
text_metadata[key] = val
|
||||||
|
except Exception:
|
||||||
|
pass
|
||||||
|
elif chunk_type == b"iTXt":
|
||||||
|
parts = chunk_data.split(b"\x00", 1)
|
||||||
|
if len(parts) == 2:
|
||||||
|
key = parts[0].decode("utf-8", errors="ignore")
|
||||||
|
remaining = parts[1]
|
||||||
|
if len(remaining) >= 2:
|
||||||
|
comp_flag = remaining[0]
|
||||||
|
comp_method = remaining[1]
|
||||||
|
rem = remaining[2:]
|
||||||
|
parts2 = rem.split(b"\x00", 1)
|
||||||
|
if len(parts2) == 2:
|
||||||
|
lang_tag = parts2[0].decode("utf-8", errors="ignore")
|
||||||
|
rem = parts2[1]
|
||||||
|
parts3 = rem.split(b"\x00", 1)
|
||||||
|
if len(parts3) == 2:
|
||||||
|
trans_key = parts3[0].decode("utf-8", errors="ignore")
|
||||||
|
text_bytes = parts3[1]
|
||||||
|
if comp_flag == 1 and comp_method == 0:
|
||||||
|
try:
|
||||||
|
val = zlib.decompress(text_bytes).decode("utf-8", errors="ignore")
|
||||||
|
text_metadata[key] = val
|
||||||
|
except Exception:
|
||||||
|
pass
|
||||||
|
else:
|
||||||
|
val = text_bytes.decode("utf-8", errors="ignore")
|
||||||
|
text_metadata[key] = val
|
||||||
|
elif chunk_type == b"IEND":
|
||||||
|
break
|
||||||
|
idx += 12 + length
|
||||||
|
return text_metadata
|
||||||
|
# }}}
|
||||||
@@ -18,9 +18,9 @@ def check_for_flag(text: str, pattern: str | None = None) -> list[str]:
|
|||||||
patterns.append(pattern.strip("^$"))
|
patterns.append(pattern.strip("^$"))
|
||||||
else:
|
else:
|
||||||
try:
|
try:
|
||||||
from ctf.config import load_config
|
from ctf.config import Config
|
||||||
config = load_config()
|
cfg = Config()
|
||||||
flag_format = config.get("Competition", {}).get("flag_format", "")
|
flag_format = cfg.data.get("Competition", {}).get("flag_format", "")
|
||||||
except Exception:
|
except Exception:
|
||||||
flag_format = ""
|
flag_format = ""
|
||||||
if flag_format:
|
if flag_format:
|
||||||
@@ -74,13 +74,12 @@ class FlagDetectorStream:
|
|||||||
for match in matches:
|
for match in matches:
|
||||||
self.original_stream.write(f" \033[1;32m✓ {match}\033[0m\n")
|
self.original_stream.write(f" \033[1;32m✓ {match}\033[0m\n")
|
||||||
try:
|
try:
|
||||||
from ctf.config import load_config, write_config
|
from ctf.config import Config
|
||||||
config_path = "/home/venus/code/ctf/config.toml"
|
cfg = Config()
|
||||||
config = load_config(config_path)
|
if "Competition" not in cfg.data:
|
||||||
if "Competition" not in config:
|
cfg.data["Competition"] = {}
|
||||||
config["Competition"] = {}
|
cfg.data["Competition"]["last_flag"] = match
|
||||||
config["Competition"]["last_flag"] = match
|
cfg.save(cfg.data)
|
||||||
write_config(config, config_path)
|
|
||||||
except Exception:
|
except Exception:
|
||||||
pass
|
pass
|
||||||
self._flag_buffer = ""
|
self._flag_buffer = ""
|
||||||
|
|||||||
@@ -1,31 +1,15 @@
|
|||||||
# src/main.py
|
# src/main.py
|
||||||
# Parses and calls commands
|
# Parses and calls commands
|
||||||
|
|
||||||
from ctf.commands import basic_group
|
|
||||||
from ctf.cli_forensics import forensics_group
|
|
||||||
from ctf.cli_steg import steg_group
|
|
||||||
from ctf.cli_analyse import analyse_cmd
|
|
||||||
from ctf.cli_helpers import flag_cmd
|
|
||||||
from ctf.helpers import FlagDetectorStream, detector_state
|
|
||||||
import click
|
|
||||||
import sys
|
import sys
|
||||||
|
from ctf.cli import cli
|
||||||
# {{{ cli
|
from ctf.helpers import FlagDetectorStream, detector_state
|
||||||
@click.group()
|
|
||||||
def cli(): pass
|
|
||||||
|
|
||||||
cli.add_command(forensics_group)
|
|
||||||
cli.add_command(basic_group)
|
|
||||||
cli.add_command(flag_cmd)
|
|
||||||
cli.add_command(steg_group)
|
|
||||||
cli.add_command(analyse_cmd)
|
|
||||||
# }}}
|
|
||||||
|
|
||||||
# {{{ main
|
# {{{ main
|
||||||
def main():
|
def main():
|
||||||
from ctf.config import load_config
|
from ctf.config import Config
|
||||||
config = load_config("/home/venus/code/ctf/config.toml")
|
cfg = Config()
|
||||||
flag_format = config.get("Competition", {}).get("flag_format", "")
|
flag_format = cfg.data.get("Competition", {}).get("flag_format", "")
|
||||||
|
|
||||||
if flag_format:
|
if flag_format:
|
||||||
detector = FlagDetectorStream(sys.stdout, flag_format)
|
detector = FlagDetectorStream(sys.stdout, flag_format)
|
||||||
|
|||||||
@@ -2,7 +2,7 @@
|
|||||||
# basic utilities
|
# basic utilities
|
||||||
|
|
||||||
from pathlib import Path
|
from pathlib import Path
|
||||||
from ctf.config import load_config, competition, enviroment
|
from ctf.config import competition, enviroment
|
||||||
|
|
||||||
# return a list of path objects for each catagory in a competition
|
# return a list of path objects for each catagory in a competition
|
||||||
def active_categories(p: Path) -> list:
|
def active_categories(p: Path) -> list:
|
||||||
|
|||||||
Reference in New Issue
Block a user