mail-address-semantics/experiments/postfix-probe/probe.py

#!/usr/bin/env python3
"""Send MAS test addresses through a real Postfix and report what arrived.

    python experiments/postfix-probe/probe.py --profile defaults
    python experiments/postfix-probe/probe.py --profile defaults-local
    python experiments/postfix-probe/probe.py --profile mas-safe-local
    python experiments/postfix-probe/probe.py --profile mas-profile --corpus

Starts the mas-postfix-probe container, sends one message per address via
SMTP, then compares the envelope recipient Postfix handed to mas-gateway
with the one that was sent.
"""

import argparse
import json
import smtplib
import subprocess
import sys
import time
import urllib.request
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]
D = "great-service.example"
# (label, local-part as sent in RCPT TO). "{ID}" is filled with the created ticket id.
CASES = [
    ("P2 intake", "ticket!callback"),
    ("resource", "ticket={ID}"),
    ("resource + facet", "ticket={ID}+comments"),
    ("extra '=' in id", "ticket==X1"),
    ("registry function", "support"),
    ("person-style", "bernd.worsch"),
    ("upper-case local-part", "Ticket={ID}"),
    ("percent data", "ticket=PR%2B42"),
    ("percent hack form", "ticket%other.example"),
    ("bang in resource", "ticket={ID}!web"),
    ("facet + interaction", "ticket={ID}+comments!callback"),
    ("reserved $", "ticket=PR42$4.99"),
    ("quoted local-part", '"ticket=PR42"'),
    ("unknown resource", "ticket=DOES-NOT-EXIST"),
]
# Relay attempts: the MAS profile must refuse all of them (not an open relay).
RELAY_NEGATIVES = ["x@other.example", "x!y@other.example", "a@other.example@" + D,
                   "a@" + D + "@other.example", "x%y@other.example"]




def unquoted(addr):
    """Strip RFC 5321 quoting. Postfix hands ${recipient} over in canonical
    form: needless quotes dropped, quotes added around non-dot-atoms."""
    local, _, dom = (addr or "").rpartition("@")
    if len(local) > 1 and local[0] == local[-1] == '"':
        local = local[1:-1]
    return f"{local}@{dom}"


def corpus_cases():
    """Every distinct local-part of the shared conformance corpus."""
    seen, out = set(), []
    for c in json.loads((ROOT / "mas_conformance/addresses.json").read_text()):
        if c["local_part"] not in seen:
            seen.add(c["local_part"])
            out.append((f"corpus {c['id']}", c["local_part"]))
    return out


def run(profile, port, corpus=False):
    name = f"mas-probe-{profile}"
    subprocess.run(["docker", "rm", "-f", name], capture_output=True)
    subprocess.run(["docker", "run", "-d", "--name", name, "-e", f"PROFILE={profile}",
                    "-v", f"{ROOT}:/mas:ro", "-p", f"127.0.0.1:{port}:25",
                    "-p", f"127.0.0.1:{port + 1}:8024", "mas-postfix-probe"], check=True,
                   capture_output=True)
    try:
        for _ in range(60):
            try:
                smtplib.SMTP("127.0.0.1", port, timeout=2).quit()
                break
            except OSError:
                time.sleep(0.5)
        results, tid = [], None
        for label, lp in CASES + (corpus_cases() if corpus else []):
            rcpt_lp = lp.replace("{ID}", tid or "MISSING")
            rcpt = f"{rcpt_lp}@{D}"
            msg = (f"From: probe@example.net\r\nTo: {rcpt}\r\nSubject: {label}\r\n"
                   f"Message-ID: <{abs(hash(rcpt))}@example.net>\r\n\r\nprobe\r\n")
            before = len(events(port))
            try:
                with smtplib.SMTP("127.0.0.1", port, timeout=10) as s:
                    refused = s.sendmail("probe@example.net", [rcpt], msg)
                smtp = "accepted" if not refused else f"refused {refused}"
            except (smtplib.SMTPException, UnicodeEncodeError) as e:
                smtp = f"rejected: {e}"
            got = wait_event(port, before) if smtp == "accepted" else None
            arrived = got["event"]["recipient"] if got else None
            mas = got["event"]["mas"] if got else {}
            app = got["app"] if got else None
            if label == "P2 intake" and app:
                tid = app.get("ticket_id")
            results.append({"label": label, "sent": rcpt, "smtp": smtp, "arrived_as": arrived,
                            "unchanged": arrived == rcpt,
                            "equivalent": arrived is not None and unquoted(arrived) == unquoted(rcpt),
                            "mas_valid": mas.get("valid"), "kind": mas.get("kind"),
                            "app_status": got["app_status"] if got else None,
                            "app": (app or {}).get("status") if isinstance(app, dict) else app})
        for rcpt in RELAY_NEGATIVES:
            try:
                with smtplib.SMTP("127.0.0.1", port, timeout=10) as s:
                    refused = s.sendmail("probe@example.net", [rcpt], f"Subject: relay\r\n\r\nx\r\n")
                smtp = "accepted" if not refused else f"refused {refused}"
            except smtplib.SMTPException as e:
                smtp = f"rejected: {e}"
            results.append({"label": "relay attempt", "sent": rcpt, "smtp": smtp, "arrived_as": None,
                            "unchanged": False, "relay_refused": smtp != "accepted"})
        logs = subprocess.run(["docker", "logs", name], capture_output=True, text=True)
        return results, logs.stdout + logs.stderr
    finally:
        subprocess.run(["docker", "rm", "-f", name], capture_output=True)


def events(port):
    with urllib.request.urlopen(f"http://127.0.0.1:{port + 1}/") as r:
        return json.loads(r.read())


def wait_event(port, before, timeout=15):
    end = time.time() + timeout
    while time.time() < end:
        ev = events(port)
        if len(ev) > before:
            return ev[-1]
        time.sleep(0.3)
    return None


if __name__ == "__main__":
    ap = argparse.ArgumentParser()
    ap.add_argument("--profile", choices=["mas-profile", "defaults", "defaults-local", "mas-safe-local",
                                          "local-domain", "local-domain-safe"], default="mas-profile")
    ap.add_argument("--port", type=int, default=2525)
    ap.add_argument("--corpus", action="store_true", help="also send every conformance-corpus local-part")
    ap.add_argument("--json", metavar="FILE")
    ap.add_argument("--log", metavar="FILE")
    a = ap.parse_args()
    results, log = run(a.profile, a.port, a.corpus)
    for r in results:
        mark = ("R" if r["relay_refused"] else "X") if "relay_refused" in r else ("=" if r["unchanged"] else "~" if r["equivalent"] else "!")
        print(f"{mark} {r['label']:<22} {r['sent']:<52} -> {r['arrived_as'] or r['smtp']}"
              f"  [{r.get('kind')}/{r.get('app')}]")
    if a.json:
        Path(a.json).write_text(json.dumps({"profile": a.profile, "results": results}, indent=2) + "\n")
    if a.log:
        Path(a.log).write_text(log)
    sys.exit(0)