47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
#!/usr/bin/env python3
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"""Flagging rules for the intrusion-detection system.
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Detection functions that identify hostile IPs based on aggregated stats.
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"""
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from __future__ import annotations
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from . import bad_patterns
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from .models import IPStats
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def flag_scanners(stats: dict[str, IPStats], min_errors: int = 5,
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min_ratio: float = 0.5) -> dict[str, IPStats]:
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"""IPs with many errors AND a high error ratio."""
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return {
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ip: s for ip, s in stats.items()
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if s.errors >= min_errors and s.error_ratio >= min_ratio
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}
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def flag_denied_only(stats: dict[str, IPStats],
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min_denied: int = 1) -> dict[str, IPStats]:
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"""IPs that only ever hit denied paths and never authenticated."""
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return {
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ip: s for ip, s in stats.items()
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if s.denied >= min_denied and not s.authenticated
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}
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def flag_malicious_patterns(stats: dict[str, IPStats],
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min_severity: int = 2,
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min_hits: int = 1) -> dict[str, IPStats]:
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"""IPs with hits against malicious path patterns at or above severity threshold."""
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return {
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ip: s for ip, s in stats.items()
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if s.malicious_hits >= min_hits and any(
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bad_patterns.PATTERNS_BY_NAME[name].severity >= min_severity
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for name in s.malicious_patterns
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)
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}
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def by_total(stats: dict[str, IPStats]) -> list[IPStats]:
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"""Stats sorted by request count, descending."""
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return sorted(stats.values(), key=lambda s: (-s.total, s.ip))
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