Metadata-Version: 2.4
Name: w4f
Version: 0.1.39
Summary: Passive TLS / CDN / WAF / edge fingerprinting of API endpoints
Author: hdyrawan
License-Expression: MIT
Project-URL: Homepage, https://github.com/hdyrawan/w4f
Project-URL: Repository, https://github.com/hdyrawan/w4f
Project-URL: Issues, https://github.com/hdyrawan/w4f/issues
Keywords: cdn,waf,fingerprint,tls,edge,dns,security,recon
Classifier: Development Status :: 4 - Beta
Classifier: Environment :: Console
Classifier: Intended Audience :: Information Technology
Classifier: Intended Audience :: System Administrators
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: 3.12
Classifier: Topic :: Security
Classifier: Topic :: Internet :: WWW/HTTP
Requires-Python: >=3.10
Description-Content-Type: text/markdown
License-File: LICENSE
Provides-Extra: full
Requires-Dist: cryptography; extra == "full"
Requires-Dist: dnspython; extra == "full"
Provides-Extra: dev
Requires-Dist: pytest>=8; extra == "dev"
Requires-Dist: cryptography; extra == "dev"
Requires-Dist: dnspython; extra == "dev"
Dynamic: license-file
Dynamic: requires-python

# w4f

```
                 █████ █████     ██████
                ░░███ ░░███     ███░░███
 █████ ███ █████ ░███  ░███ █  ░███ ░░░
░░███ ░███░░███  ░███████████ ███████
 ░███ ░███ ░███  ░░░░░░░███░█░░░███░
 ░░███████████         ░███░   ░███
  ░░████░████          █████   █████
   ░░░░ ░░░░          ░░░░░   ░░░░░
 passive TLS / CDN / WAF / edge fingerprinting · v0.1.39
```

[![tests](https://github.com/hdyrawan/w4f/actions/workflows/ci.yml/badge.svg)](https://github.com/hdyrawan/w4f/actions/workflows/ci.yml)
[![pypi](https://img.shields.io/pypi/v/w4f?cache_bust=1)](https://pypi.org/project/w4f/)
[![python](https://img.shields.io/badge/python-3.10--3.12-blue)](https://pypi.org/project/w4f/)
[![license](https://img.shields.io/badge/license-MIT-green)](LICENSE)

[Release notes → CHANGELOG.md](CHANGELOG.md) ·
[Vendor signature reference → docs/vendor-signatures.md](docs/vendor-signatures.md) ·
[Attribution model → docs/attribution-model.md](docs/attribution-model.md)

Passive **TLS / CDN / WAF / edge fingerprinting** for API endpoints. For any
`host[:port]` it walks the standard client path — DNS (A/AAAA/CNAME/PTR), one
SNI TLS handshake, one GET — and matches the collected signals (response
headers, cookies, certificate issuer/org, CNAME/PTR suffixes, IP netblocks)
against a vendor signature table to **name the edge in front of the origin**.

```bash
w4f --target-file hosts.txt
```

```
HOST                  EDGE              CONF  BASIS                       TLS     CERT               HTTP  NOTES
www.example.com:443   cloudflare +2  HIGH 85  net+cert+cname+http+cookie  1.3 h2  Cloudflare 55d      200
shop.example.net:443  AMBIGUOUS       MED 42  cname+ptr+http              1.3 h2  Amazon 60d          200
edge.example.io:443   unknown              -  -                           1.3 h2  Let's Encrypt 40d   200
inspected.example.org:443  INTERCEPTED          -  -                           1.3 h2  Fortinet -168d      403  INTERCEPTED
www.example.net:443   akamai          LOW 20  cname                       -       -                     -  ERR connect failed: timed out

# www.example.com is cleanly attributed — its table row says it all, so it
# gets no block. Only the hosts that need a look do:

shop.example.net:443
  EDGE    AMBIGUOUS
    aws-cloudfront                MEDIUM 42
    cloudflare                    MEDIUM 37
  BASIS
    aws-cloudfront      cname + ptr + http
    cloudflare          net + http

edge.example.io:443
  EDGE    UNKNOWN
  leads   cname edge.provider.net · server: acme-edge · x-acme-pop: sin1

inspected.example.org:443  INTERCEPTED
  EDGE    NOT DETERMINED
  PATH    INTERCEPTED by fortinet
          the identity below may belong to the interception device, not this host
  OBSERVED
    IP        198.51.100.40
    Issuer    Fortinet
    SPKI      9701081eeeeeeeee…

www.example.net:443  ERR connect failed: timed out
  akamai                        LOW    20
  cname   (cloud)
  error   connect failed: timed out
```

`BASIS` is the column that decides whether to believe the row: `net+cert`
is ownership evidence, a bare `hdr` is a string the origin can set. Default
mode is **table-first**: cleanly attributed hosts are just their table row,
and only hosts that need a look (unknown, ambiguous, intercepted, error,
block page, mTLS, a competing edge) get a detail block; the sweep ends with a
rollup. `-v`/`--verbose` prints the full block for every host — see
[Example output](#example-output).

No attack payloads. Nothing is chain-validated the way a client trusts it —
this is fingerprinting, not trusting — so self-signed and privately-pinned
endpoints are fingerprinted too, and the **SPKI-SHA-256 pin value** is
reported per certificate, which is exactly the value an app's custom pinner
compares against.

An optional `--verify` flag sends **one benign `<script>` query** to catch
silent WAFs (FortiWeb, F5 ASM) that answer normal requests with plain nginx
and only reveal themselves when they block something. Off by default.

## Why this exists

Knowing what edge sits in front of a host decides which interception route can
work at all:

- **Cloudflare / anycast** — a DNAT written against one resolved IP matches
  zero packets, because your resolver and the device's resolver return
  different IPs. The route is SNI-based, not IP-based.
- **Imperva edge** — the host may demand a **client certificate** at the TLS
  layer (mutual TLS). A proxy that can't present one gets `stream reset by
  client` after a perfectly correct app-side pinning bypass.
- **CloudFront / GFE / ELB** — the origin is behind a managed edge; whether
  the origin itself is reachable by name tells you where the capture ceiling
  is.
- **Silent WAFs (FortiWeb)** — serve `nginx` headers to every passive
  request; only an attack-shaped query gets their block page back. Passive
  scanning alone would report them as a bare origin.

This tool makes that a 2-second decision instead of an hour of guessing.

## Install

**Requirements:** Python **3.10–3.12**, nothing mandatory. `cryptography`
adds full certificate details (issuer, SAN, SPKI pin, key/sig) and `dnspython`
adds proper CNAME/PTR resolution; without either the scanner degrades
gracefully (socket fallback for DNS, cert fields omitted) and the test suite
still passes.

### Option 1 — pipx (recommended, isolated CLI install)

```bash
pipx install w4f
w4f --version
```

### Option 2 — uv tool

```bash
uv tool install w4f
w4f --version
```

### Option 3 — plain pip

Prefer a virtual environment so the `w4f` script lands on your PATH:

```bash
python3 -m venv .venv && source .venv/bin/activate   # Windows: .venv\Scripts\activate
pip install w4f
w4f --version
```

Install with the optional extras (certificate + DNS depth) in one step:

```bash
pip install "w4f[full]"
```

### Option 4 — unreleased `main`, or a clone

```bash
pipx install git+https://github.com/hdyrawan/w4f.git   # or uv tool / pip
```

Or from a clone:

```bash
git clone https://github.com/hdyrawan/w4f.git && cd w4f
pip install .
w4f --version
```

### Option 5 — run without installing

From a clone you can run it directly, no install step at all:

```bash
git clone https://github.com/hdyrawan/w4f.git && cd w4f
python3 -m w4f --target api.example.com
```

### For development

```bash
git clone https://github.com/hdyrawan/w4f.git && cd w4f
python3 -m venv .venv && source .venv/bin/activate
pip install -e .            # editable: code changes apply immediately
python3 -m pytest           # run the test suite
```

### Verify & uninstall

```bash
w4f --version        # e.g. "w4f 0.1.36 — passive TLS / CDN / WAF / edge fingerprinting"
w4f --help           # full usage
pipx uninstall w4f   # or: uv tool uninstall w4f / pip uninstall w4f
```

## Library use

The same engine the CLI drives is exposed as a plain Python function —
useful for scheduling, scripting, or building your own sweep tooling:

```python
from w4f import fingerprint_host

r = fingerprint_host("api.example.com", verify=True)
top = r["verdict"][0]                         # ranked by confidence
print(top["vendor"], top["confidence"])       # cloudflare 82
print(top["categories"])                      # ['netblock', 'cert', 'cname', 'headers']
print(r["block"]["vendor"] if r["block"] else "no WAF block")    # needs verify=True
```

`verdict` is ranked by **confidence**, so `verdict[0]` is the best-evidenced
vendor. `categories` (added 0.1.32) lists the signal kinds behind the score,
strongest first — a verdict whose categories are only `headers`/`cookies`
rests on strings the origin can set.

Returns the same per-host dict the CLI's `--json` output contains (`host`,
`hostport`, `port`, `resolved`, `tls`, `verdict`, `block`, `error`). Accepts
`port`, `timeout`, `path`, `no_http`, `verify`, `ws_path`, `grpc` — the CLI
flag equivalents. Errors are a field, never an exception: a host that fails
DNS comes back with `error` set and `verdict == []`.

## Usage

```bash
# one host
w4f --target api.example.com

# several hosts, one pass
w4f --target mapi.example.com --target api.example.net --target api.example.org

# a non-443 port (API/data sockets often sit off 443)
w4f --target api.example.net:6552

# an IP literal (PTR is still resolved)
w4f --target 203.0.113.10

# scan every subdomain from a subdomain-enumeration export
w4f --target-json subdomains.json --json out.json --md out.md

# plain-text host list (one per line; # comments and blanks ignored)
w4f --target-file hosts.txt

# CSV target list (uses the host/subdomain column when present, else column 1)
w4f --target-csv targets.csv

# pipeline: subdomain enumeration straight into w4f (stdin is read when no
# explicit target source is given and stdin is not a TTY)
subfinder -d example.com -silent | w4f --csv sweep.csv

# flat CSV output for spreadsheets (primary verdict per host)
w4f --target-file hosts.txt --csv sweep.csv

# SARIF 2.1.0 for security dashboards / GitHub Code Scanning
w4f --target-file hosts.txt --sarif scan.sarif

# WebSocket upgrade probe (RFC 6455) against a path
w4f --target ws.example.com --ws /socket.io

# gRPC health-check probe (grpc.health.v1.Health/Check)
w4f --target grpc.example.com --grpc

# pace requests: --delay N seconds between per-host submissions
# (per-domain backoff: 429/503 doubles the delay up to 10s, success resets)
w4f --target-file hosts.txt --delay 0.5 --csv sweep.csv

# catch silent WAFs with the one-query active probe
w4f --target api.example.com --verify

# machine-readable + markdown sweep, quiet console
w4f --target api.example.com --quiet --json out.json --md out.md

# TLS/cert/DNS only — skip the HTTP request entirely
w4f --target api.example.com --no-http
```

### Flags

| flag | meaning |
|---|---|
| `--target HOST[:PORT]` | DNS name or IP, optional `:port` (default 443). Repeatable. |
| `--target-json FILE` | targets from a JSON file — subdomain-enumeration export (array of `{"subdomain","ip","cloudflare"}` objects, e.g. subdomainfinder.c99.nl), array of strings, or `{subdomains:[...]}`. Each is scanned like a `--target`. |
| `--target-file FILE` | plain-text host list, one `host[:port]` per line; `#` comments and blank lines ignored |
| `--target-csv FILE` | CSV target list — uses the column named `host`/`subdomain` when the first row is a header, else the first column |
| `--path PATH` | HTTP path to GET (default `/`) |
| `--timeout SECONDS` | connect/TLS/HTTP timeout per host (default 8) |
| `--workers N` | parallel host count (default 8) |
| `--delay SECONDS` | base pacing between per-host submissions (default 0 = as fast as possible). Per-domain adaptive backoff: a `429`/`503` doubles that domain's delay (cap 10s), a success resets it to the base. |
| `--json FILE` | write the full machine-readable result tree to FILE |
| `--md FILE` | write a markdown sweep (table + per-host blocks) to FILE |
| `--csv FILE` | write a flat CSV — one row per host, primary verdict: host, port, ips, cname, verdict, confidence, signals, mtls, tls_version, alpn, spki, http_status, block, error, basis, final_host |
| `--sarif FILE` | write a SARIF 2.1.0 report for security dashboards / GitHub Code Scanning — one result per host, rule ids `w4f/<vendor>`, `w4f/block`, `w4f/mtls`, `w4f/probe-error`, `w4f/unknown-edge` |
| `--sort risk\|host\|edge` | console ordering (default `risk`: errors, block pages, mTLS, unknown and header-only verdicts first). `host` = alphabetical, `edge` = grouped by vendor. File outputs are always host-sorted. |
| `-v`, `--verbose` | show the FULL per-host detail (cert, SPKI, response headers, verdict evidence) instead of the compact triage view — the summary table prints either way |
| `--no-banner` | suppress the ASCII banner + version tagline — output starts at the summary table (for piping the table into scripts) |
| `--no-http` | TLS/cert/DNS only, skip the HTTP request |
| `--ws PATH` | **OPT-IN** — send an RFC 6455 WebSocket upgrade request to this path and report whether the edge answers `101` (plus `Sec-WebSocket-Accept`) |
| `--grpc` | **OPT-IN** — send a `grpc.health.v1.Health/Check` request and report `grpc-status` / `grpc-message`, or the HTTP/2 binary-framing answer (real gRPC is h2; pairs with the ALPN observation) |
| `--verify` | **OPT-IN active probe** — one benign `<script>` query per host; reports the WAF block page (FortiWeb / F5 ASM / Cloudflare / Imperva) |
| `--version` | print version and exit |
| `--quiet` | suppress ALL console output (banner, summary table, per-host blocks, rollup) — use with `--json`/`--md`/`--csv` for automation |

Targets may come from `--target`, `--target-json`, `--target-file`,
`--target-csv`, or — when none of those is given and stdin is not a TTY —
from stdin (one host per line). All sources go through the same validation
(control chars / URI schemes / overlong names dropped with a warning) and
are deduplicated after validation. Targets scan in
parallel; the console orders them by risk (`--sort`) while file outputs stay
sorted by host for clean run-over-run diffs. Progress and file paths go to stderr,
the report to stdout — so `w4f ... > report.txt` and `w4f ... --quiet --json
out.json | jq ...` keep the machine output clean.

The banner is the Rebel figlet "w4f" (patorjk taag style, x=none full-width)
with `w` in red and `f` in blue. It prints on every non-quiet run, on
**stderr**, so stdout stays parseable.

### Example output

```bash
$ w4f --target api.example.com --target shop.example.net --timeout 6
```

```
                 █████ █████     ██████
                ░░███ ░░███     ███░░███
 █████ ███ █████ ░███  ░███ █  ░███ ░░░
░░███ ░███░░███  ░███████████ ███████
 ░███ ░███ ░███  ░░░░░░░███░█░░░███░
 ░░███████████         ░███░   ░███
  ░░████░████          █████   █████
   ░░░░ ░░░░          ░░░░░   ░░░░░
  passive TLS / CDN / WAF / edge fingerprinting   v0.1.39

HOST                    EDGE         CONF     BASIS               TLS     CERT                 HTTP  NOTES
dead.example.io:443     -            -                            -       -                       -  ERR DNS did not resolve
api.example.com:443     imperva +1   MED 62   net+cert+hdr        1.3 h2  Imperva Inc 64d       403  mTLS  BLOCK imperva!
edge.example.io:443     UNKNOWN      -                            1.3 h2  GlobalSign nv… 161d   200
origin.example.org:443  nginx        LOW 7    hdr                 1.3 h2  Let's Encrypt 21d     200
shop.example.net:443    cloudflare   HIGH 82  net+cert+cname+hdr  1.3 h2  SSL Corporati… 73d    200  ->www.shop.example.net

dead.example.io:443  ERR DNS did not resolve
  error   DNS did not resolve

api.example.com:443  mTLS  BLOCK imperva!
  imperva                       MEDIUM 62
  net + cert + hdr
  layer   imperva → nginx

edge.example.io:443
  EDGE    UNKNOWN
  leads   server: acme-edge · x-acme-pop: sin1 · x-acme-request-id

── 5 hosts · 3.4s ──────────────────────────────────────────────────────
edges     cloudflare 1 · imperva 1 · nginx 1
unknown   1  (edge.example.io:443)
flags     mTLS 1 · BLOCK 1 · errors 1
weak      1 verdict rests on headers only (spoofable) — confirm with --verify
```

Default mode is the **triage view** and is deliberately **table-first**: a
summary table of every host, then a sweep rollup, and a per-host block **only
for the hosts that need a look** — an error, a block page, mTLS, an unknown
edge, an ambiguous or intercepted result, or a genuinely competing edge. The
two cleanly-attributed hosts above (`shop.example.net`, `origin.example.org`)
are fully described by their table row, so they get no block — that is what
keeps a 50-host sweep scannable. Reach for `-v`/`--verbose` (below) when you
want the full analytical block for *every* host.

Each block is shaped by the result **state**, because "no vendor name" has
several very different causes and collapsing them loses the decision:

| state | meaning |
|---|---|
| `ATTRIBUTED` (named vendor) | one candidate is best-evidenced; the vendor is named |
| `AMBIGUOUS` | edge candidates too close to separate — both are shown, rather than silently picking the higher |
| `UNKNOWN` | scanned, nothing matched. The observations/leads are the start of the next signature |
| `INTERCEPTED` | something on the **scanner's** path re-signed the connection; no vendor is attributed and the cert/pin may be the middlebox's |
| `ERROR` | the host could not be probed. A host that failed *but* resolved a vendor CNAME still reports that vendor — DNS resolves before the handshake |

`layer` is the stack, not a rival: an origin underneath the edge
(`cloudflare → varnish`) is reported as a **layer**, while `alt` lists only
competing *edge* candidates. Presenting an origin as an alternative edge was
the misreading this split removes.

`CONF` is the confidence **band** first (`HIGH` ≥ 70, `MED` ≥ 30, `LOW`
below) and the score second. The score is a sum of category weights, not a
probability, so `HIGH` means several independent kinds of evidence agreed —
more than the strongest single category can supply alone. `BASIS` names
those categories (`net` netblock, `cert`, `cname`, `ptr`, `hdr` header,
`cookie`); a bare `hdr` is a string the origin can set, and the block marks
it *headers only — spoofable*.

The full model is documented in
[`docs/attribution-model.md`](docs/attribution-model.md).

Add `-v` / `--verbose` for the analytical view — the same observations plus
**why** the attribution was reached: the evidence behind it grouped by
category, and the alternatives that were in play.

```
$ w4f -v --target www.example.com

www.example.com:443
ip        104.18.1.79
cname     www.example.com.cdn.cloudflare.net
tls       TLSv1.3  TLS_AES_256_GCM_SHA384  ALPN h2
cert      Cloudflare, Inc.  (chain verified)
  san     www.example.com, *.example.com
  valid   2026-06-05 -> 2026-12-11  (55d left)
  spki    343d1536f3666f92ea868d751d138dd8658d3020426b4de28801cb259f5bdde7
http      HTTP/1.1 200 OK
  hdr     server=cloudflare
  hdr     x-varnish=1234567 7654321

EDGE
  cloudflare                    HIGH   85
    net + cert + cname + http + cookie   (cloud)

EVIDENCE
  Network
    104.18.1.79 in 104.16.0.0/13
  Certificate
    Cloudflare, Inc.
  CNAME
    www.example.com.cdn.cloudflare.net
  HTTP
    server: cloudflare
  Cookie
    __cf_bm=xyz

LAYER
  cloudflare
      ↓
  varnish

ALTERNATIVES
  cloudflare-waf                LOW     3
    cookie
```

`EVIDENCE` is one category per heading and one observation per line, so it
answers "what would have to be false for this to be wrong" — a verdict
resting on a netblock and a certificate is a different claim from one
resting on a header. `LAYER` draws the stack the edge fronts; `ALTERNATIVES`
holds only competing edges. Scores appear as one number per candidate; the
arithmetic behind them stays out of the output.

The `chain`/`final` rows matter more than they look: the apex is often a
bare redirector and the WAF only sits on `www`, so they say which host the
headers above actually describe.

(The hosts above are illustrative — run it against any real host to see your
own output.)

Colors are enabled automatically when stdout is a TTY (piped output is plain
text), and disabled with `NO_COLOR`. The host line is cyan, **critical flags
(mTLS / BLOCK / ERR) are bold bright red**, redirect markers and `--verify`
block findings yellow — and each **vendor name has its own color** so a glance names the
edge: Cloudflare bright-yellow, Akamai blue, Fastly red, AWS family cyan,
Azure family bright-blue, Tencent family bright-magenta, Google GFE
magenta, F5/netscaler bright-red, FortiWeb bright-yellow, Kong bright-cyan,
and plain origin stacks (nginx, Apache, IIS, Varnish, …) are **dimmed** so
the edge vs origin distinction is instantly visible. The color map is in
`w4f/report.py` (`VENDOR_COLORS`) — a new vendor gets a green default; add
an entry there if it deserves its own hue.

## What it reports

| signal | source |
|---|---|
| resolved IPs (A+AAAA) + PTR | DNS |
| CNAME chain | DNS |
| TLS version / cipher / ALPN | TLS handshake |
| leaf cert: subject, issuer org, SAN, validity, SHA-256, **SPKI-SHA-256**, key/sig | TLS handshake |
| mTLS flag (server wants a client cert, incl. TLS 1.3 post-handshake) | TLS alert / first app data |
| HTTP status + interesting headers | one GET |
| WebSocket upgrade support (`--ws`) | RFC 6455 upgrade request |
| gRPC health-check support (`--grpc`) | grpc.health.v1.Health/Check |
| redirect chain + final host (apex → www) | one GET, up to 5 hops |
| CDN/WAF verdict + evidence + confidence + signal categories + cloud/on-prem | signature match |
| `interception` — a TLS-inspection box on the scanner's own path | cert issuer / its refusal page |
| `block` — WAF block page (vendor, title, status) | `--verify` active probe |

## Reading a verdict

A host behind nginx directly gets `nginx` only; a host behind Imperva gets
`imperva` from headers **and** cert **and** netblock, every matching signal
listed as evidence:

```
imperva (62%, net+cert+hdr): header x-iinfo: 7-1234567-…; netblock: … ; cert: Imperva Inc
```

Every match carries a **confidence (0–100)** summed from weighted signal
categories, **each category counted once**:

| category | weight | why |
|---|---|---|
| `net` netblock | 30 | IP ownership is hard to spoof |
| `cert` issuer | 25 | cert issuance is authoritative |
| `cname` chain | 20 | DNS delegation is deliberate |
| `ptr` record | 15 | real evidence, but often generic or missing |
| `hdr` headers | 7 | weak alone — anyone can set a `Server:` header |
| `cookie` cookies | 3 | weakest — trivially fabricated |

Because each category counts once, **the percentage is not a probability and
signal count is not confidence**: six matching headers still score 7, while
one netblock hit scores 30. That is why the category list (`BASIS` in the
table, `categories` in the JSON) is the part to read — it says whether a
verdict rests on evidence the origin cannot fabricate. A verdict built only
from `hdr`/`cookie` is marked *headers only — spoofable*.

**Verdicts are ranked by confidence**, so `verdict[0]` — the vendor the
table, `--csv` and SARIF call the edge — is the best-evidenced one. A second
entry is usually the origin behind that edge (`imperva` in front of
`nginx`), shown as `+1` in the table and on a `layer` line in the block
(default mode prints that block only when the host also warrants a look; see
the triage-view note above).
Per-vendor `weights` overrides are allowed; see
[`docs/vendor-signatures.md`](docs/vendor-signatures.md) for the full table
and the "why" behind each signal.

- **A blank verdict** means the edge is not in the signature table — treat it
  as "unknown origin, no WAF/CDN signature", **not** "no WAF". The block
  prints a `leads` line with the fingerprintable headers that matched
  nothing, which is where a new signature starts.
- **A passive "direct nginx" verdict is NOT proof of a bare origin.** FortiWeb
  and F5 ASM serve plain nginx to normal requests; run `--verify` before
  concluding the origin is exposed.
- **`--verify` findings** are reported separately (`block fortiweb — ...`)
  so the passive and active layers never blur.

## Security notes

- **Input validation.** Targets from `--target-json` are validated at load:
  control characters, URI schemes (`file://` etc.), whitespace-in-hostname,
  and overlong names (>253 chars) are dropped with a warning. **Private /
  internal IPs (10.x, 192.168.x, 127.x, 169.254.x) are warned but NOT
  dropped** — scanning internal infrastructure is a legitimate use. Only run
  w4f against targets you are authorised to scan.
- **The reported SPKI-SHA-256 is a fingerprint, not a trust anchor.** w4f
  reports the pin value the edge presents; it does not verify it against any
  expected set (this is a fingerprinting tool, not a certificate-verification
  tool). A reported pin implies nothing about whether the endpoint is
  legitimate — an attacker's certificate has a pin value too.
- **Output can disclose infrastructure details.** `--json` includes cert
  chains, SPKI pins, CNAME/PTR records and resolved IPs (including internal
  ones when you scan them). Treat the output as sensitive and do not share it
  inadvertently.
- **The unverified TLS context is deliberate.** Certificate verification is
  disabled (via the public `ssl.create_default_context()` + `CERT_NONE`) so
  that self-signed / expired / wrong-hostname certs can still be read as
  evidence — which is the entire point of edge fingerprinting. This means an
  active MITM between w4f and the target is not detected; the tool reports
  what it was actually presented.

**AWS WAF on CloudFront is silent to passive probes** — a normal GET returns
200 and only `--verify` sees the 403 block page. **Do not write "CloudFront,
no WAF" for a host without a `--verify` run** — same trap as FortiWeb (which
serves plain nginx to normal requests). See
[`docs/vendor-signatures.md`](docs/vendor-signatures.md) and the
[CHANGELOG](CHANGELOG.md) for the version-by-version detection additions
(AWS Global Accelerator, Kong, AWS WAF, Tencent EdgeOne, squarespace, ...).

### Signature coverage

**94 vendors** across seven families — each one a file under
`w4f/signatures/` (copy `_template.py` to add one; see
[`docs/vendor-signatures.md`](docs/vendor-signatures.md) for the
contributor guide):

- **CDN/edge** (38): Cloudflare, Cloudflare WAF, Imperva, Akamai (incl.
  Kona + Bot Manager `E3D=`), AWS CloudFront / WAF / ELB / Global
  Accelerator / S3 / EC2, Fastly (+ WAF/Signal Sciences), Azure Front Door,
  Azure App Gateway, ArvanCloud, Tencent EdgeOne / CDN, Baidu Yunjiasu,
  Baidu BFE, Baidu CDN, Alibaba CDN, Wangsu, ChinaCache, Huawei Cloud CDN,
  Volcengine DCDN, ByteDance, 360 PanYun, Baishan, NetEase CDN,
  Qiniu, JD Cloud, Airee, Azion, Edgecast, MaxCDN, KeyCDN, StackPath,
  Zenedge, DDoS-Guard.
- **WAF/protection** (23): FortiWeb, F5 BIG-IP ASM, NetScaler, GTM/GSLB,
  Sucuri, ModSecurity, NAXSI, Wallarm, Wordfence, Zscaler, Google Cloud
  Armor, Radware, Reblaze, Barracuda, Huawei Cloud WAF, SafeDog, Jiasule,
  Wangsu WAF (wswaf), Knownsec Chuang Yu Shield, 360 WangZhanBao (WZWS),
  Qrator, Variti, UCloud WAF (uewaf).
- **Bot management** (5): DataDome, PerimeterX/HUMAN, Kasada, Shape
  Security, Arkose.
- **API gateways / platform edges** (15): Kong, Tyk, Apigee, Azure API
  Management, Tencent gateway (stgw/tRPC), Envoy, HAProxy, Tengine,
  OpenResty, Cloudflare Workers, Vercel, Google Cloud Run, AWS App Runner,
  SGW (Shopee/Sea), **WSO2** (API Manager / Carbon gateway).
- **Plain origins** (6): nginx, Apache, IIS, Caddy, LiteSpeed, Varnish.
- **Platforms** (6): Google GFE, Wix Pepyaka, Squarespace, Azure App
  Service, ByteDance TLB, **WordPress VIP** (`x-rq` POP header +
  `go-vip.net` CNAME).
- **Middleboxes** (1): **Fortinet WebFilter** — an appliance on the
  *scanner's* own path, not the target's edge. Reported as `INTERCEPTED`
  (never as a verdict) because a re-signed chain means the SPKI pin belongs
  to the middlebox, not the host.

Plus `--verify` block-page signatures for FortiWeb (EN + localized ID),
F5 ASM, Cloudflare, Imperva and **AWS WAF** ("ERROR: The request could not
be satisfied"), Akamai Kona, Sucuri, Wordfence, Wallarm.

Signatures are a snapshot; a new edge version can change headers, so re-run
sweeps before trusting a blank verdict for a host whose writeup is old.

## JSON output

`--json` writes the full per-host result tree. Every host is one object;
errors are a field, not an exception — a bad host never aborts the run:

```json
[
  {
    "host": "api.example.com",
    "hostport": "api.example.com:443",
    "port": 443,
    "resolved": { "cname": ["api.example.com.cdn.cloudflare.net"], "ips": ["104.18.1.79"], "ptr": [] },
    "tls": {
      "tls_version": "TLSv1.3",
      "cipher": "TLS_AES_256_GCM_SHA384",
      "alpn": "h2",
      "mtls": false,
      "chain_verified": true,
      "cert": { "subject": "CN=api.example.com", "issuer": "O=Cloudflare, Inc.", "issuer_org": "Cloudflare, Inc.", "spki_sha256": "343d1536...", "key_type": "RSA", "key_size": 2048, "days_remaining": 118 },
      "http": { "status": "HTTP/1.1 404 Not Found", "headers": { "server": "cloudflare", "cf-ray": "a2af..." }, "set-cookie-list": [], "redirects": [], "final_host": "api.example.com" }
    },
    "verdict": [
      { "vendor": "cloudflare", "signals": 7, "confidence": 82, "categories": ["netblock", "cert", "cname", "headers"], "evidence": ["header server: cloudflare", "cname: api.example.com.cdn.cloudflare.net", ...] }
    ],
    "block": null
  }
]
```

`verdict` is ordered by confidence (best-evidenced first). `categories` is
strongest-first and is what the console renders as `BASIS`.

### Scripting

```bash
# the verdict for every host
w4f --target-json subdomains.json --quiet --json out.json
jq -r '.[] | "\(.hostport)\t\(.verdict[0].vendor // "unknown")"' out.json

# only hosts behind a specific edge
jq -r '.[] | select(.verdict[].vendor == "cloudflare") | .hostport' out.json

# every host whose --verify probe found a WAF block page
jq -r '.[] | select(.block) | "\(.hostport)\t\(.block.vendor)"' out.json

# fail if any host errored (exit code already does this, but jq can too)
jq -e '[.[] | select(.error)] | length == 0' out.json > /dev/null

# verdicts resting only on spoofable headers/cookies — re-check these
jq -r '.[] | select((.verdict | length) > 0 and (.verdict[0].categories | inside(["headers","cookies"])))
       | "\(.hostport)\t\(.verdict[0].vendor)"' out.json

# unknown edges: the queue for the next signature file
jq -r '.[] | select(.error == null and (.verdict | length) == 0) | .hostport' out.json

# SPKI-SHA-256 pin values for every host
jq -r '.[] | "\(.hostport)\t\(.tls.cert.spki_sha256)"' out.json
```

### Exit codes

| code | meaning |
|---|---|
| `0` | everything scanned cleanly |
| `1` | at least one host errored (DNS failure, connect refused, probe exception) — results still written |
| `2` | usage error — no target source at all, unreadable `--target-json` |

## Testing

```bash
pip install .[dev]
python -m pytest
```

287 tests, offline — a local TLS server with a self-signed cert exercises the
real socket path without touching the internet. Coverage: fingerprint
matching against real-world cases from live sweep corpora + false-positive
guards (requires-gate positives/negatives, Cloudflare-WAF low-confidence,
fastly cache-node vs marketing-site, regional CloudFront
netblocks); confidence-first verdict ranking; the `--verify` block-page
matcher (FortiWeb EN/ID, F5 ASM,
Cloudflare, Imperva, AWS WAF, Akamai Kona, the title-at-end-of-39KB-body
trap); the modular signature loader (package discovery, nested subpackages,
duplicate-name / bad-regex / missing-name / unknown-key / bad-netblock
rejection, `W4F_SIGNATURES` env override); rate limiting; WS/gRPC probes;
SARIF schema shape; CSV/JSON/MD writers; CLI/report/banner (summary-table
columns and alignment under color, triage-block facts, unknown-edge leads,
sweep rollup, display ordering, per-vendor verdict colors); and end-to-end
`probe_one` against the local server.

CI (GitHub Actions) runs the suite on Python 3.10/3.11/3.12 with full extras,
a no-optional-deps job proving graceful degradation, and a CLI smoke check.

## Known limits

- **Passive layer cannot see silent WAFs.** FortiWeb and F5 ASM serve plain
  nginx to normal requests; only the opt-in `--verify` probe (one benign
  `<script>` query) makes them answer with a block page. `--verify` is still
  not a full exploit-style sweep.
- **The signature table is a snapshot.** New edge versions can change
  headers/cookies; re-run before trusting a blank verdict for an old writeup.
- **`--verify` reads the block page title** — a WAF that localizes its block
  page beyond the EN + ID fragments matched here would need a new signature.
- **Bare IP targets resolve PTR but not CNAME** (there is no CNAME for an IP).

## License

MIT — see [LICENSE](LICENSE).
