remi zrewidował ten Gist 1 week ago. Przejdź do rewizji
Brak zmian
remi zrewidował ten Gist 1 week ago. Przejdź do rewizji
2 files changed, 88 insertions
hooks.yaml(stworzono plik)
| @@ -0,0 +1,33 @@ | |||
| 1 | + | - id: debug | |
| 2 | + | execute-command: /usr/local/bin/log-hook.sh | |
| 3 | + | include-command-output-in-response: true | |
| 4 | + | pass-arguments-to-command: | |
| 5 | + | - source: entire-headers | |
| 6 | + | - source: raw-request-body | |
| 7 | + | - id: liberaforms | |
| 8 | + | execute-command: /usr/local/bin/verify-hook.py | |
| 9 | + | include-command-output-in-response: true | |
| 10 | + | pass-arguments-to-command: | |
| 11 | + | - source: header | |
| 12 | + | name: X-Timestamp | |
| 13 | + | - source: header | |
| 14 | + | name: X-Signature-256 | |
| 15 | + | - source: raw-request-body | |
| 16 | + | pass-environment-to-command: | |
| 17 | + | - source: string | |
| 18 | + | name: foobar | |
| 19 | + | envname: WEBHOOK_SECRET | |
| 20 | + | trigger-rule: | |
| 21 | + | and: | |
| 22 | + | - match: | |
| 23 | + | type: regex | |
| 24 | + | regex: '^[0-9a-f]{64}$' | |
| 25 | + | parameter: | |
| 26 | + | source: header | |
| 27 | + | name: X-Signature-256 | |
| 28 | + | - match: | |
| 29 | + | type: regex | |
| 30 | + | regex: '^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d{1,6})?(Z|[+-]\d{2}:\d{2})$' | |
| 31 | + | parameter: | |
| 32 | + | source: header | |
| 33 | + | name: X-Timestamp | |
verify-hook.py(stworzono plik)
| @@ -0,0 +1,55 @@ | |||
| 1 | + | #!/usr/bin/env python3 | |
| 2 | + | import os | |
| 3 | + | import sys | |
| 4 | + | import hmac | |
| 5 | + | import hashlib | |
| 6 | + | from datetime import datetime, timezone | |
| 7 | + | ||
| 8 | + | MAX_SKEW = 300 # secondes | |
| 9 | + | ||
| 10 | + | def main(): | |
| 11 | + | if len(sys.argv) != 4: | |
| 12 | + | print("INVALIDE: arguments manquants (attendu: timestamp signature raw_body)") | |
| 13 | + | return 1 | |
| 14 | + | ||
| 15 | + | timestamp, signature, body_arg = sys.argv[1:4] | |
| 16 | + | signature = signature.removeprefix("sha256=") | |
| 17 | + | ||
| 18 | + | secret = os.environ.get("WEBHOOK_SECRET", "") | |
| 19 | + | if not secret: | |
| 20 | + | print("INVALIDE: WEBHOOK_SECRET non défini") | |
| 21 | + | return 1 | |
| 22 | + | ||
| 23 | + | # 1. Fraîcheur du timestamp | |
| 24 | + | try: | |
| 25 | + | ts = datetime.fromisoformat(timestamp) | |
| 26 | + | if ts.tzinfo is None: | |
| 27 | + | ts = ts.replace(tzinfo=timezone.utc) | |
| 28 | + | except ValueError: | |
| 29 | + | print(f"INVALIDE: timestamp illisible ({timestamp})") | |
| 30 | + | return 1 | |
| 31 | + | ||
| 32 | + | skew = abs((datetime.now(timezone.utc) - ts).total_seconds()) | |
| 33 | + | if skew > MAX_SKEW: | |
| 34 | + | print(f"INVALIDE: timestamp trop ancien/futur ({skew:.0f}s d'écart)") | |
| 35 | + | return 1 | |
| 36 | + | ||
| 37 | + | # 2. Signature sur les octets bruts + timestamp | |
| 38 | + | # os.fsencode restitue les octets exacts reçus dans argv | |
| 39 | + | raw_body = os.fsencode(body_arg) | |
| 40 | + | ||
| 41 | + | expected = hmac.new( | |
| 42 | + | secret.encode("utf-8"), | |
| 43 | + | raw_body + timestamp.encode("utf-8"), | |
| 44 | + | hashlib.sha256, | |
| 45 | + | ).hexdigest() | |
| 46 | + | ||
| 47 | + | if not hmac.compare_digest(expected, signature): | |
| 48 | + | print("INVALIDE: signature incorrecte") | |
| 49 | + | return 1 | |
| 50 | + | ||
| 51 | + | print("VALIDE") | |
| 52 | + | return 0 | |
| 53 | + | ||
| 54 | + | if __name__ == "__main__": | |
| 55 | + | sys.exit(main()) | |
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