Security Ownership Map

Overview

Build a bipartite graph of people and files from git history, then compute ownership risk and export graph artifacts for Neo4j/Gephi. Also build a file co-change graph (Jaccard similarity on shared commits) to cluster files by how they move together while ignoring large, noisy commits.

Requirements

• Python 3

• networkx (required; community detection is enabled by default)

Install with:

pip install networkx

Workflow

• Scope the repo and time window (optional --since/--until).

• Decide sensitivity rules (use defaults or provide a CSV config).

• Build the ownership map with scripts/run_ownership_map.py (co-change graph is on by default; use --cochange-max-files to ignore supernode commits).

• Communities are computed by default; graphml output is optional (--graphml).

• Query the outputs with scripts/query_ownership.py for bounded JSON slices.

• Persist and visualize (see references/neo4j-import.md).

By default, the co-change graph ignores common “glue” files (lockfiles, .github/*, editor config) so clusters reflect actual code movement instead of shared infra edits. Override with --cochange-exclude or --no-default-cochange-excludes. Dependabot commits are excluded by default; override with --no-default-author-excludes or add patterns via --author-exclude-regex.

If you want to exclude Linux build glue like Kbuild from co-change clustering, pass:

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \

  --repo /path/to/linux \

  --out ownership-map-out \

  --cochange-exclude "**/Kbuild"

Quick start

Run from the repo root:

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \

  --repo . \

  --out ownership-map-out \

  --since "12 months ago" \

  --emit-commits

Defaults: author identity, author date, and merge commits excluded. Use --identity committer, --date-field committer, or --include-merges if needed.

Example (override co-change excludes):

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \

  --repo . \

  --out ownership-map-out \

  --cochange-exclude "**/Cargo.lock" \

  --cochange-exclude "**/.github/**" \

  --no-default-cochange-excludes

Communities are computed by default. To disable:

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \

  --repo . \

  --out ownership-map-out \

  --no-communities

Sensitivity rules

By default, the script flags common auth/crypto/secret paths. Override by providing a CSV file:

# pattern,tag,weight

**/auth/**,auth,1.0

**/crypto/**,crypto,1.0

**/*.pem,secrets,1.0

Use it with --sensitive-config path/to/sensitive.csv.

Output artifacts

ownership-map-out/ contains:

• people.csv (nodes: people)

• files.csv (nodes: files)

• edges.csv (edges: touches)

• cochange_edges.csv (file-to-file co-change edges with Jaccard weight; omitted with --no-cochange)

• summary.json (security ownership findings)

• commits.jsonl (optional, if --emit-commits)

• communities.json (computed by default from co-change edges when available; includes maintainers per community; disable with --no-communities)

• cochange.graph.json (NetworkX node-link JSON with community_id + community_maintainers; falls back to ownership.graph.json if no co-change edges)

• ownership.graphml / cochange.graphml (optional, if --graphml)

people.csv includes timezone detection based on author commit offsets: primary_tz_offset, primary_tz_minutes, and timezone_offsets.

LLM query helper

Use scripts/query_ownership.py to return small, JSON-bounded slices without loading the full graph into context.

Examples:

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out people --limit 10

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag auth --bus-factor-max 1

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out person --person alice@corp --limit 10

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out file --file crypto/tls

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out cochange --file crypto/tls --limit 10

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section orphaned_sensitive_code

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out community --id 3

Use --community-top-owners 5 (default) to control how many maintainers are stored per community.

Basic security queries

Run these to answer common security ownership questions with bounded output:

# Orphaned sensitive code (stale + low bus factor)

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section orphaned_sensitive_code

# Hidden owners for sensitive tags

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section hidden_owners

# Sensitive hotspots with low bus factor

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section bus_factor_hotspots

# Auth/crypto files with bus factor <= 1

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag auth --bus-factor-max 1

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag crypto --bus-factor-max 1

# Who is touching sensitive code the most

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out people --sort sensitive_touches --limit 10

# Co-change neighbors (cluster hints for ownership drift)

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out cochange --file path/to/file --min-jaccard 0.05 --limit 20

# Community maintainers (for a cluster)

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out community --id 3

# Monthly maintainers for the community containing a file

python skills/skills/security-ownership-map/scripts/community_maintainers.py \

  --data-dir ownership-map-out \

  --file network/card.c \

  --since 2025-01-01 \

  --top 5

# Quarterly buckets instead of monthly

python skills/skills/security-ownership-map/scripts/community_maintainers.py \

  --data-dir ownership-map-out \

  --file network/card.c \

  --since 2025-01-01 \

  --bucket quarter \

  --top 5

Notes:

• Touches default to one authored commit (not per-file). Use --touch-mode file to count per-file touches.

• Use --window-days 90 or --weight recency --half-life-days 180 to smooth churn.

• Filter bots with --ignore-author-regex '(bot|dependabot)'.

• Use --min-share 0.1 to show stable maintainers only.

• Use --bucket quarter for calendar quarter groupings.

• Use --identity committer or --date-field committer to switch from author attribution.

• Use --include-merges to include merge commits (excluded by default).

Summary format (default)

Use this structure, add fields if needed:

{

  "orphaned_sensitive_code": [

    {

      "path": "crypto/tls/handshake.rs",

      "last_security_touch": "2023-03-12T18:10:04+00:00",

      "bus_factor": 1

    }

  ],

  "hidden_owners": [

    {

      "person": "alice@corp",

      "controls": "63% of auth code"

    }

  ]

}

Graph persistence

Use references/neo4j-import.md when you need to load the CSVs into Neo4j. It includes constraints, import Cypher, and visualization tips.

Notes

• bus_factor_hotspots in summary.json lists sensitive files with low bus factor; orphaned_sensitive_code is the stale subset.

• If git log is too large, narrow with --since or --until.

• Compare summary.json against CODEOWNERS to highlight ownership drift.