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Author SHA1 Message Date
a969657536 Add an egress CIDR allowlist to the SSRF guard (closes #204)
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The SSRF blocklist had no escape hatch, so the thing webhooker is
mostly for — taking a public webhook and forwarding it to something
on your own network — could not be configured at all. Every private
address, Docker sibling and loopback service was permanently
unreachable as a delivery destination.

ALLOWED_EGRESS_CIDRS (default empty) names blocks that delivery
targets may reach despite the default blocklist. It is an allowlist
and only ever adds destinations: there is no boolean, and no value
disables SSRF protection wholesale. Empty, it adds nothing and the
guard permits and refuses the same addresses it did before, save
the two spellings named below.

A small set of addresses is refused before the allowlist is
consulted, so no supplied CIDR opens one — not the exact address,
not a supernet, not 0.0.0.0/0 or ::/0. alwaysBlockedNetworks in
internal/delivery/ssrf.go is the authoritative list and states the
membership criterion in full; it is deliberately not copied here,
because a copy drifts out of date. In short: the provider fixes the
address, so a host route for it collides with nothing the operator
runs, and reaching it discloses credentials or user data. A
publicly routable address never qualifies however well it meets
both — nothing in this set can be reopened, so blocking one here
would leave the operator no escape hatch at all. Those belong in
blockedNetworks, which an allowlist can override.

Every entry is already inside the default blocklist, which is what
makes it unconditional rather than newly blocked, with two
exceptions that are the one behaviour change visible when the
allowlist is unset: ::a9fe:a9fe and 64:ff9b::a9fe:a9fe, the
IPv4-compatible and NAT64 spellings of 169.254.169.254, were
reachable before and are refused now. net.IPNet.Contains normalises
only the IPv4-mapped form via To4(), so 169.254.0.0/16 never
matched those two. The ten it does cover now report a metadata
error rather than the generic private-range one.

The policy now lives in one function, Guard.checkIP, which both
target-creation validation and the delivery dialer call. The two
paths previously decided separately, which is how they came to
disagree about a destination. The guard is built once from config
and injected via fx into both the handlers and the delivery engine,
so there is a single instance and a single answer.

A set-but-unparseable value aborts startup naming the variable,
reusing the existing envPrefixList parser. A non-empty list is
logged at startup with the blocks spelled out, not counted, so the
hole is visible in the log of any deployment that has one.

Tests: an allowlisted loopback CIDR both validates and delivers to a
live server (and the same URL still fails without the allowlist); a
private address outside the listed block stays refused on both
paths; every unconditionally blocked address stays refused on both
paths under an allowlist that covers it, and the set itself is
pinned entry by entry; public addresses are unaffected either way;
and config coverage for parsing, startup abort, and the warning's
contents.
2026-08-20 08:27:32 +00:00
afe88c601a refactor: use pinned golangci-lint Docker image for linting (#55)
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Closes [issue #50](#50)

## Summary

Refactors the Dockerfile to use a separate lint stage with a pinned golangci-lint Docker image, following the pattern used by [sneak/pixa](https://git.eeqj.de/sneak/pixa). This replaces the previous approach of installing golangci-lint via curl in the builder stage.

## Changes

### Dockerfile
- **New `lint` stage** using `golangci/golangci-lint:v2.11.3` (Debian-based, pinned by sha256 digest) as a separate build stage
- **Builder stage** depends on lint via `COPY --from=lint /src/go.sum /dev/null` — build won't proceed unless linting passes
- **Go bumped** from 1.24 to 1.26.1 (`golang:1.26.1-bookworm`, pinned by sha256)
- **golangci-lint bumped** from v1.64.8 to v2.11.3
- All three Docker images (golangci-lint, golang, alpine) pinned by sha256 digest
- Debian-based golangci-lint image used (not Alpine) because mattn/go-sqlite3 CGO does not compile on musl (off64_t)

### Linter Config (.golangci.yml)
- Migrated from v1 to v2 format (`version: "2"` added)
- Removed linters no longer available in v2: `gofmt` (handled by `make fmt-check`), `gosimple` (merged into `staticcheck`), `typecheck` (always-on in v2)
- Same set of linters enabled — no rules weakened

### Code Fixes (all lint issues from v2 upgrade)
- Added package comments to all packages
- Added doc comments to all exported types, functions, and methods
- Fixed unchecked errors flagged by `errcheck` (sqlDB.Close, os.Setenv in tests, resp.Body.Close, fmt.Fprint)
- Fixed unused parameters flagged by `revive` (renamed to `_`)
- Fixed `gosec` G120 warnings: added `http.MaxBytesReader` before `r.ParseForm()` calls
- Fixed `staticcheck` QF1012: replaced `WriteString(fmt.Sprintf(...))` with `fmt.Fprintf`
- Fixed `staticcheck` QF1003: converted if/else chain to tagged switch
- Renamed `DeliveryTask` → `Task` to avoid package stutter (`delivery.Task` instead of `delivery.DeliveryTask`)
- Renamed shadowed builtin `max` parameter to `upperBound` in `cryptoRandInt`
- Used `t.Setenv` instead of `os.Setenv` in tests (auto-restores)

### README.md
- Updated version requirements: Go 1.26+, golangci-lint v2.11+
- Updated Dockerfile description in project structure

## Verification

`docker build .` passes cleanly — formatting check, linting, all tests, and build all succeed.

Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de>
Reviewed-on: #55
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
2026-03-25 02:16:38 +01:00
60786c5019 feat: add CSRF protection, SSRF prevention, and login rate limiting (#42)
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## Security Hardening

This PR implements three security hardening issues:

### CSRF Protection (closes #35)

- Session-based CSRF tokens with cryptographically random 256-bit generation
- Constant-time token comparison to prevent timing attacks
- CSRF middleware applied to `/pages`, `/sources`, `/source`, and `/user` routes
- Hidden `csrf_token` field added to all 12+ POST forms in templates
- Excluded from `/webhook` (inbound webhook POSTs) and `/api` (stateless API)

### SSRF Prevention (closes #36)

- `ValidateTargetURL()` blocks private/reserved IP ranges at target creation time
- Blocked ranges: `127.0.0.0/8`, `10.0.0.0/8`, `172.16.0.0/12`, `192.168.0.0/16`, `169.254.0.0/16`, `::1`, `fc00::/7`, `fe80::/10`, plus multicast, reserved, test-net, and CGN ranges
- SSRF-safe HTTP transport with custom `DialContext` in the delivery engine for defense-in-depth (prevents DNS rebinding attacks)
- Only `http` and `https` schemes allowed

### Login Rate Limiting (closes #37)

- Per-IP rate limiter using `golang.org/x/time/rate`
- 5 attempts per minute per IP on `POST /pages/login`
- GET requests (form rendering) pass through unaffected
- Automatic cleanup of stale per-IP limiter entries every 5 minutes
- `X-Forwarded-For` and `X-Real-IP` header support for reverse proxies

### Files Changed

**New files:**
- `internal/middleware/csrf.go` + tests — CSRF middleware
- `internal/middleware/ratelimit.go` + tests — Login rate limiter
- `internal/delivery/ssrf.go` + tests — SSRF validation + safe transport

**Modified files:**
- `internal/server/routes.go` — Wire CSRF and rate limit middleware
- `internal/handlers/handlers.go` — Inject CSRF token into template data
- `internal/handlers/source_management.go` — SSRF validation on target creation
- `internal/delivery/engine.go` — SSRF-safe HTTP transport for production
- All form templates — Added hidden `csrf_token` fields
- `README.md` — Updated Security section and TODO checklist

`docker build .` passes (lint + tests + build).

Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de>
Co-authored-by: clawbot <clawbot@eeqj.de>
Co-authored-by: Jeffrey Paul <sneak@noreply.example.org>
Reviewed-on: #42
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
2026-03-17 12:38:45 +01:00