procurement-ingest/cdk
Adam Moussa 447b0619ad
Add fail-closed SES sender authentication
The From header and any raw-MIME Authentication-Results copies are
attacker-forgeable, so a forged email to apm@int.seahaven.com or
amazon_po@int.seahaven.com could create or mutate a WO/PO (INFRA-107,
CRITICAL). Both S3-triggered email processors now authenticate the
sender against the Authentication-Results header SES itself prepends
at delivery: only the topmost header is consulted, its authserv-id
must be amazonses.com, and it must carry dkim=pass for a domain in
the per-pipeline ALLOWED_DKIM_DOMAINS env var (comma-separated, set
in CDK so ops can adjust without code changes).

Allowlists come from live traffic observed 2026-07-15 on both ingest
buckets: WO mail arrives via the apm@ Google Groups forward, which
re-signs as seahaven.com (the hxgnsmartcloud.com signature does not
survive the forward); PO mail passes for amazon.coupahost.com.
amazonses.com also passes on PO mail but is deliberately excluded --
every SES customer's outbound mail passes for it.

Every failure path (env var unset, header missing or unparseable,
verdict fail, unaligned domain) rejects the email: a structured
warning with the reason and S3 key is logged and the record skipped
without erroring the invocation, so rejected mail causes no Lambda
retries or DLQ messages. Handler signatures and event sources are
unchanged.

Refs: INFRA-107
2026-07-15 18:53:46 -04:00
..
app.py Merge workorder-ingest into unified procurement repo (#22) 2026-05-12 15:21:06 -04:00
cdk.json Initial commit: PO email ingestion pipeline 2026-04-07 12:12:30 -04:00
po_stack.py Add fail-closed SES sender authentication 2026-07-15 18:53:46 -04:00
requirements.txt Bump aws-cdk-lib in /cdk in the minor-and-patch group across 1 directory (#86) 2026-07-07 18:20:00 +00:00
wo_stack.py Add fail-closed SES sender authentication 2026-07-15 18:53:46 -04:00