openvpncertupdate/docs/superpowers/plans/2026-08-15-cert-days.md

# Configurable Certificate Lifetime Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Let the operator choose how long an issued certificate is valid, via a `CERT_DAYS` setting, a `--days` CLI flag, and a Days field in the TUI cert form — while leaving today's behaviour unchanged for anyone who doesn't set it.

**Architecture:** One resolver, `resolve_cert_days()`, turns every input path (SETTINGS constant, external `.conf`, CLI flag, TUI field) into either `""` (omit the flag, let EasyRSA's own `EASYRSA_CERT_EXPIRE` win) or a normalised decimal string. `build_client_full()` appends `--days=N` to its own argument list when that string is non-empty. The CLI resolves once in `main()` and overwrites the module global, exactly as `CA_PASSPHRASE` already does; the TUI carries a per-cert value out of the form instead.

**Tech Stack:** Python 3.9, stdlib `argparse` and `curses`, existing `ConfigError` / `_base_cmd()` / `InputField` / `show_cert_form()` in `openvpncertupdate.py`. Tests via `pytest` + `unittest.mock`, following the mock-curses patterns already in `tests/test_dialogs.py` and `tests/test_widgets.py`.

**Design doc:** `docs/superpowers/specs/2026-08-15-cert-days-design.md`

## Global Constraints

- Single-file script: all production code stays in `openvpncertupdate.py`; no new modules.
- `"default"` and `""` both mean *inherit from EasyRSA* — deploying this must never silently shorten certificates on an existing PKI. Do not change the shipped value to a number.
- `--days` goes in `build_client_full()`'s own argument list. **Never** in `_base_cmd()` — that helper is shared with `gen-crl`, where `--days` sets CRL validity instead (`easyrsa:7270`).
- Rejecting `0` locally is a fast-fail mirror of EasyRSA's own gate (`easyrsa:5701`), not a substitute for it. Do not add a `--days=0` code path expecting EasyRSA to accept it.
- Leading zeros are normalised (`"090"` → `"90"`) because EasyRSA's own validation pattern `*[!1234567890]*|0*` (`easyrsa:7178`) rejects them with a message that makes no sense to someone who typed only digits.
- Follow existing conventions: `CliRunner` reads module globals directly (`EASYRSA_DIR`, `EASYRSA_PKI_DIR`, `CA_PASSPHRASE`) rather than threading them as parameters.
- Every task ends with the full suite green: `python3 -m pytest tests/ -q`.

**Two deliberate deviations from the spec:**

1. The spec's data-flow sketch has `CliRunner.create()`/`.reissue()` take a `days` parameter. This plan instead resolves into the module global `CERT_DAYS` in `main()`. Reason: it matches the established `CA_PASSPHRASE` pattern exactly, avoids threading one value through three call layers, and leaves the existing `test_main_dispatches_*` signature assertions intact. Behaviour is identical.
2. The spec says the TUI shows "the `resolve_cert_days()` message" on the hint line. The form window is 62 columns wide, leaving 58 for the hint, and the resolver's full sentence is longer than that — it would be truncated mid-word. The form still *validates* with `resolve_cert_days()`, so what counts as valid never diverges, but renders its own short message.

---

## File Structure

- **Modify `openvpncertupdate.py`:**
  - SETTINGS: add `CERT_DAYS` constant; add it to `_OVERRIDABLE_SETTINGS`.
  - EASYRSA section: add `resolve_cert_days()` beside `resolve_ca_passphrase()`; add a `days` parameter to `build_client_full()`.
  - TUI WIDGETS: add an `allowed` charset parameter to `InputField`.
  - TUI DIALOGS: add a `days` field to `CertFormResult` and `show_cert_form()`; grow the window; validate on submit.
  - APP: `_process_cert()` seeds the form from `CERT_DAYS` and forwards `form.days`.
  - CLI: add `--days` to `_build_parser()`; resolve in `main()`; `_issue()` passes the global.
- **Modify `tests/test_easyrsa.py`:** `resolve_cert_days()` table; `build_client_full` flag presence/absence; `--days` absent from revoke/gen-crl commands.
- **Modify `tests/test_widgets.py`:** `InputField` charset filtering.
- **Modify `tests/test_dialogs.py`:** Days field behaviour; **fix two existing tests whose keypress counts assume three fields**.
- **Modify `tests/test_cli.py`:** `--days` parsing and dispatch.
- **Modify `tests/test_config_file.py`:** `CERT_DAYS` survives a `.conf` override.
- **Modify `CLAUDE.md`:** flags table, SETTINGS mention, key constraints.

---

### Task 1: `CERT_DAYS` setting and `resolve_cert_days()`

**Files:**
- Modify: `openvpncertupdate.py` (SETTINGS block ~line 75; `_OVERRIDABLE_SETTINGS` ~line 81; EASYRSA section, after `resolve_ca_passphrase()` ~line 380)
- Test: `tests/test_easyrsa.py`, `tests/test_config_file.py`

**Interfaces:**
- Consumes: `ConfigError` (defined in the SETTINGS OVERRIDE section).
- Produces: `resolve_cert_days(configured, name: str = "CERT_DAYS") -> str` — returns `""` or a normalised decimal string; raises `ConfigError`. Module constant `CERT_DAYS: str`.

- [ ] **Step 1: Write the failing tests**

Add to `tests/test_easyrsa.py`, importing `resolve_cert_days` and `ConfigError` alongside the existing imports:

```python
# ---------------------------------------------------------------------------
# resolve_cert_days
# ---------------------------------------------------------------------------

@pytest.mark.parametrize("configured", ["default", "", "  ", "  default  "])
def test_resolve_cert_days_sentinels_mean_inherit(configured):
    # "" and "default" leave the lifetime to EasyRSA's own EASYRSA_CERT_EXPIRE,
    # so deploying this cannot silently shorten certs on an existing PKI.
    assert resolve_cert_days(configured) == ""


@pytest.mark.parametrize("configured,expected", [
    (90, "90"), ("90", "90"), ("  90  ", "90"), (1, "1"), (3650, "3650"),
])
def test_resolve_cert_days_accepts_positive_numbers(configured, expected):
    assert resolve_cert_days(configured) == expected


def test_resolve_cert_days_normalises_leading_zeros():
    # EasyRSA's own pattern rejects "090" with "Number expected", which reads
    # as nonsense to someone who typed only digits.
    assert resolve_cert_days("090") == "90"


def test_resolve_cert_days_rejects_zero():
    with pytest.raises(ConfigError, match="positive"):
        resolve_cert_days("0")


@pytest.mark.parametrize("configured", ["-5", -5, "abc", "9 0", "90.5", 90.5, None])
def test_resolve_cert_days_rejects_junk(configured):
    with pytest.raises(ConfigError):
        resolve_cert_days(configured)


def test_resolve_cert_days_error_names_the_source():
    # The same resolver serves CERT_DAYS, --days and the TUI field; the message
    # must say which one the user actually touched.
    with pytest.raises(ConfigError, match="--days"):
        resolve_cert_days("0", "--days")
```

Add to `tests/test_config_file.py`:

```python
def test_cert_days_is_overridable(tmp_path):
    conf = tmp_path / "app.conf"
    conf.write_text('CERT_DAYS = 90\n')
    out = load_settings_overrides(str(conf), "", str(tmp_path / "app.py"))
    assert out["CERT_DAYS"] == 90
```

- [ ] **Step 2: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_easyrsa.py -k cert_days tests/test_config_file.py -q`
Expected: FAIL — `ImportError: cannot import name 'resolve_cert_days'`, and `KeyError: 'CERT_DAYS'`.

- [ ] **Step 3: Add the setting**

In the SETTINGS block, directly after `DAYS_AHEAD  = 14`:

```python
CERT_DAYS   = "default"  # lifetime of certs this tool issues, in days.
                         # "default" or "" = leave it to EasyRSA (your vars'
                         # EASYRSA_CERT_EXPIRE). A positive integer overrides
                         # it — e.g. 90.
```

In `_OVERRIDABLE_SETTINGS`, change the `DAYS_PAST` line to:

```python
    "DAYS_PAST", "DAYS_AHEAD", "CERT_DAYS",
```

- [ ] **Step 4: Add the resolver**

In the EASYRSA section, directly after `resolve_ca_passphrase()`:

```python
def resolve_cert_days(configured, name: str = "CERT_DAYS") -> str:
    """Resolve a configured certificate lifetime into an EasyRSA --days value.

      "default" / "" → ""  (omit --days; EasyRSA's EASYRSA_CERT_EXPIRE wins)
      positive number → that many days, normalised ("090" → "90")

    Rejects 0, negatives and non-numeric input. EasyRSA rejects those itself,
    but failing here keeps the error next to the input the user actually typed
    — in the TUI that means the form is still open, and on the CLI it means no
    CA passphrase prompt and no subprocess round-trip first.

    `name` names the source ("CERT_DAYS", "--days", "Days") for the message.
    """
    text = str(configured).strip()
    if text in ("", "default"):
        return ""
    try:
        days = int(text)
    except ValueError:
        raise ConfigError(
            f'{name} must be a positive number of days, "default" or "" '
            f'(inherit from EasyRSA); got {configured!r}'
        )
    if days <= 0:
        raise ConfigError(
            f"{name} must be a positive number of days "
            f"(EasyRSA rejects 0); got {configured!r}"
        )
    return str(days)
```

Note `str(configured)` first: it makes `int`, `str` and `float` inputs behave uniformly, and `str(90.5)` → `"90.5"` → `ValueError`, so a float is rejected rather than silently truncated. `str(None)` → `"None"` → `ValueError`, which is also what we want.

- [ ] **Step 5: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_easyrsa.py -k cert_days tests/test_config_file.py -q`
Expected: PASS

- [ ] **Step 6: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS, no regressions.

- [ ] **Step 7: Commit**

```bash
git add openvpncertupdate.py tests/test_easyrsa.py tests/test_config_file.py
git commit -m "Add CERT_DAYS setting and resolve_cert_days()"
```

---

### Task 2: Pass `--days` to `build-client-full`

**Files:**
- Modify: `openvpncertupdate.py` — `build_client_full()` (EASYRSA section, ~line 315)
- Test: `tests/test_easyrsa.py`

**Interfaces:**
- Consumes: `_base_cmd()`, `_run_easyrsa()`, `resolve_cert_days()` output format from Task 1.
- Produces: `build_client_full(easyrsa_dir, pki_dir, cn, key_passphrase, ca_passphrase, email="", days="") -> None`.

- [ ] **Step 1: Write the failing tests**

Add to `tests/test_easyrsa.py`:

```python
@patch("openvpncertupdate.subprocess.run")
def test_build_client_full_includes_days_when_set(mock_run):
    mock_run.return_value = ok_result()
    build_client_full("/er", "/pki", "bob", "keypass", "capass", days="90")
    assert "--days=90" in mock_run.call_args[0][0]


@patch("openvpncertupdate.subprocess.run")
def test_build_client_full_omits_days_when_inheriting(mock_run):
    mock_run.return_value = ok_result()
    build_client_full("/er", "/pki", "bob", "keypass", "capass", days="")
    assert not any(a.startswith("--days") for a in mock_run.call_args[0][0])


@patch("openvpncertupdate.subprocess.run")
def test_build_client_full_days_precedes_the_verb(mock_run):
    # --days is a global option: EasyRSA parses it before the command word.
    mock_run.return_value = ok_result()
    build_client_full("/er", "/pki", "bob", "keypass", "capass", days="90")
    args = mock_run.call_args[0][0]
    assert args.index("--days=90") < args.index("build-client-full")


@patch("openvpncertupdate.subprocess.run")
def test_revoke_and_gen_crl_never_carry_days(mock_run):
    # _base_cmd() is shared with gen-crl, where --days means CRL validity.
    # Putting the flag there would quietly change how long CRLs are valid.
    mock_run.return_value = ok_result()
    revoke_issued("/er", "/pki", "alice", "capass")
    assert not any(a.startswith("--days") for a in mock_run.call_args[0][0])
    gen_crl("/er", "/pki", "capass")
    assert not any(a.startswith("--days") for a in mock_run.call_args[0][0])


@patch("openvpncertupdate.subprocess.run")
def test_error_verb_detection_survives_days_flag(mock_run):
    # _run_easyrsa picks the verb as the first non-flag arg; "--days=90"
    # must not be mistaken for it.
    mock_run.return_value = err_result(stdout="Error\nboom", stderr="")
    with pytest.raises(EasyRSAError, match="build-client-full"):
        build_client_full("/er", "/pki", "bob", "keypass", "capass", days="90")
```

- [ ] **Step 2: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_easyrsa.py -k days -q`
Expected: FAIL — `TypeError: build_client_full() got an unexpected keyword argument 'days'`.

- [ ] **Step 3: Add the parameter**

Replace `build_client_full()` entirely:

```python
def build_client_full(
    easyrsa_dir: str, pki_dir: str, cn: str,
    key_passphrase: str, ca_passphrase: str, email: str = "", days: str = "",
) -> None:
    extra_env = {"EASYRSA_REQ_EMAIL": email} if email else None
    _run_easyrsa(
        _base_cmd(easyrsa_dir, pki_dir, ca_passphrase)
        + [f"--passout=pass:{key_passphrase}"]
        # Global option, so it must precede the verb. Deliberately not in
        # _base_cmd(): gen-crl reads --days as CRL validity instead.
        + ([f"--days={days}"] if days else [])
        + ["build-client-full", cn],
        cwd=easyrsa_dir,
        extra_env=extra_env,
    )
```

- [ ] **Step 4: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_easyrsa.py -q`
Expected: PASS

- [ ] **Step 5: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 6: Commit**

```bash
git add openvpncertupdate.py tests/test_easyrsa.py
git commit -m "Pass --days to build-client-full when a lifetime is set"
```

---

### Task 3: `--days` CLI flag

**Files:**
- Modify: `openvpncertupdate.py` — `_build_parser()` (~line 1559), `main()` (~line 1593), `CliRunner._issue()` (~line 1425)
- Test: `tests/test_cli.py`

**Interfaces:**
- Consumes: `resolve_cert_days()` (Task 1), `build_client_full(days=...)` (Task 2).
- Produces: `args.days` (`Optional[str]`, default `None`); module global `CERT_DAYS` holding the resolved value by the time any `CliRunner` method runs.

- [ ] **Step 1: Write the failing tests**

Add to `tests/test_cli.py`:

```python
# ---------------------------------------------------------------------------
# --days
# ---------------------------------------------------------------------------

def test_days_flag_parses():
    args = _build_parser().parse_args(["--create", "alice", "--email", "a@b.c",
                                       "--days", "90"])
    assert args.days == "90"


def test_days_defaults_to_none_when_absent():
    args = _build_parser().parse_args(["--create", "alice", "--email", "a@b.c"])
    assert args.days is None


def test_issue_passes_resolved_days_to_build_client_full(monkeypatch, capsys):
    mocks = _patch_issue(monkeypatch)
    monkeypatch.setattr("openvpncertupdate.CERT_DAYS", "90")
    CliRunner().create("alice", "alice@example.com")
    assert mocks["build_client_full"].call_args.kwargs["days"] == "90"


def test_issue_passes_empty_days_when_inheriting(monkeypatch, capsys):
    mocks = _patch_issue(monkeypatch)
    monkeypatch.setattr("openvpncertupdate.CERT_DAYS", "")
    CliRunner().create("alice", "alice@example.com")
    assert mocks["build_client_full"].call_args.kwargs["days"] == ""


def test_main_days_flag_overrides_cert_days(monkeypatch):
    import openvpncertupdate
    monkeypatch.setattr(sys, "argv",
                        ["prog", "--create", "alice", "--email", "a@b.c", "--days", "30"])
    monkeypatch.setattr("openvpncertupdate.CERT_DAYS", "default")
    monkeypatch.setattr("openvpncertupdate.resolve_ca_passphrase", MagicMock(return_value=""))
    runner = MagicMock()
    monkeypatch.setattr("openvpncertupdate.CliRunner", MagicMock(return_value=runner))
    main()
    assert openvpncertupdate.CERT_DAYS == "30"


def test_main_resolves_cert_days_when_no_flag(monkeypatch):
    import openvpncertupdate
    monkeypatch.setattr(sys, "argv", ["prog", "--create", "alice", "--email", "a@b.c"])
    monkeypatch.setattr("openvpncertupdate.CERT_DAYS", "090")
    monkeypatch.setattr("openvpncertupdate.resolve_ca_passphrase", MagicMock(return_value=""))
    monkeypatch.setattr("openvpncertupdate.CliRunner", MagicMock(return_value=MagicMock()))
    main()
    assert openvpncertupdate.CERT_DAYS == "90"


def test_main_rejects_bad_days_flag(monkeypatch, capsys):
    monkeypatch.setattr(sys, "argv",
                        ["prog", "--create", "alice", "--email", "a@b.c", "--days", "0"])
    monkeypatch.setattr("openvpncertupdate.resolve_ca_passphrase", MagicMock(return_value=""))
    with pytest.raises(SystemExit):
        main()
    assert "--days" in capsys.readouterr().err
```

- [ ] **Step 2: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_cli.py -k days -q`
Expected: FAIL — `AttributeError: 'Namespace' object has no attribute 'days'`.

- [ ] **Step 3: Add the flag**

In `_build_parser()`, directly after the `--email` argument:

```python
    parser.add_argument("--days", metavar="N",
                        help="Certificate lifetime in days for --create/--reissue "
                             "(overrides CERT_DAYS; omit to use CERT_DAYS)")
```

- [ ] **Step 4: Resolve it in `main()`**

In `main()`, directly after `globals().update(overrides)` and **before** the `if args.list:` early return — this validates the config on every path, and unlike the CA passphrase it never prompts:

```python
    global CERT_DAYS
    try:
        CERT_DAYS = (resolve_cert_days(args.days, "--days") if args.days is not None
                     else resolve_cert_days(CERT_DAYS))
    except ConfigError as exc:
        print(f"error: {exc}", file=sys.stderr)
        sys.exit(1)
```

- [ ] **Step 5: Forward it from `_issue()`**

In `CliRunner._issue()`, change the `build_client_full` call to:

```python
            build_client_full(EASYRSA_DIR, EASYRSA_PKI_DIR, cn, password, CA_PASSPHRASE,
                              email=email_addr, days=CERT_DAYS)
```

- [ ] **Step 6: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_cli.py -q`
Expected: PASS

- [ ] **Step 7: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 8: Commit**

```bash
git add openvpncertupdate.py tests/test_cli.py
git commit -m "Add --days CLI flag overriding CERT_DAYS"
```

---

### Task 4: `InputField` charset restriction

**Files:**
- Modify: `openvpncertupdate.py` — `InputField.__init__()` and `.handle_key()` (TUI WIDGETS, ~line 647)
- Test: `tests/test_widgets.py`

**Interfaces:**
- Produces: `InputField(win, y, x, width, initial="", mask=False, allowed=None)`. When `allowed` is a string, `handle_key()` inserts only characters found in it; when `None`, behaviour is unchanged.

- [ ] **Step 1: Write the failing tests**

Add to `tests/test_widgets.py`, using whatever mock-window helper that file already defines for `InputField`:

```python
def test_allowed_charset_accepts_listed_characters():
    f = InputField(MagicMock(), 0, 0, 10, initial="", allowed="0123456789")
    for ch in "90":
        f.handle_key(ord(ch))
    assert f.value == "90"


def test_allowed_charset_drops_other_characters():
    f = InputField(MagicMock(), 0, 0, 10, initial="", allowed="0123456789")
    for ch in "9a0-!":
        f.handle_key(ord(ch))
    assert f.value == "90"


def test_allowed_none_accepts_everything():
    f = InputField(MagicMock(), 0, 0, 10, initial="")
    for ch in "a-1!":
        f.handle_key(ord(ch))
    assert f.value == "a-1!"


def test_allowed_charset_still_supports_editing_keys():
    f = InputField(MagicMock(), 0, 0, 10, initial="90", allowed="0123456789")
    f.handle_key(_curses.KEY_BACKSPACE)
    assert f.value == "9"
```

If `tests/test_widgets.py` does not already import `MagicMock` or bind `_curses`, add those imports to match the file's existing style.

- [ ] **Step 2: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_widgets.py -k allowed -q`
Expected: FAIL — `TypeError: __init__() got an unexpected keyword argument 'allowed'`.

- [ ] **Step 3: Add the parameter**

Change `InputField.__init__()`'s signature and add one attribute:

```python
    def __init__(
        self, win, y: int, x: int, width: int,
        initial: str = "", mask: bool = False, allowed: Optional[str] = None,
    ) -> None:
        self._win     = win
        self._y       = y
        self._x       = x
        self._width   = width
        self._mask    = mask
        self._allowed = allowed
        self._buf     = list(initial)
        self._cur     = len(self._buf)
```

Change the printable-character branch at the end of `handle_key()`:

```python
        elif 32 <= key <= 126:
            ch = chr(key)
            if self._allowed is not None and ch not in self._allowed:
                return
            self._buf.insert(self._cur, ch)
            self._cur += 1
```

- [ ] **Step 4: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_widgets.py -q`
Expected: PASS

- [ ] **Step 5: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 6: Commit**

```bash
git add openvpncertupdate.py tests/test_widgets.py
git commit -m "Add optional charset restriction to InputField"
```

---

### Task 5: Days field in the cert form

**Files:**
- Modify: `openvpncertupdate.py` — `CertFormResult`, `_FORM_FIELDS`, `_FORM_LABELS`, `_FORM_FIELD_Y`, `show_cert_form()` (TUI DIALOGS, ~line 738-903)
- Test: `tests/test_dialogs.py`

**Interfaces:**
- Consumes: `InputField(allowed=...)` (Task 4), `resolve_cert_days()` (Task 1), `ConfigError`.
- Produces: `CertFormResult(cn, email, password, confirmed, days="")`; `show_cert_form(stdscr, cn="", email="", password="", days="", cn_readonly=False)`.

**Watch out:** two existing tests hard-code keypress counts that assume three fields. Both must change in this task or the suite breaks.

- [ ] **Step 1: Fix the two existing tests for a fourth field**

In `tests/test_dialogs.py`, `test_show_cert_form_confirm` — the field list becomes `cn, email, days, password`, so reaching Continue takes one more Enter:

```python
def test_show_cert_form_confirm():
    """Enter advances through the 4 fields to the Continue button; Enter on
    Continue confirms.  That's 5 Enter keypresses total."""
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [10, 10, 10, 10, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="bob@example.com")
    assert isinstance(result, CertFormResult)
    assert result.confirmed is True
    assert result.cn == "bob"
    assert result.email == "bob@example.com"
    assert len(result.password) > 0
```

And `test_show_cert_form_cancel_button`:

```python
def test_show_cert_form_cancel_button():
    """Tab to the Cancel button (5 Tabs from start) and press Enter cancels."""
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    # Tab×5: cn→email→days→password→Continue→Cancel, then Enter
    win.getch.side_effect = [9, 9, 9, 9, 9, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="alice", email="alice@example.com")
    assert isinstance(result, CertFormResult)
    assert result.confirmed is False
```

In `test_show_cert_form_clamps_to_narrow_screen`, update the docstring only — `13x62` becomes `15x62`. The assertions still hold.

- [ ] **Step 2: Write the failing tests for the new behaviour**

Add to `tests/test_dialogs.py`:

```python
def test_show_cert_form_returns_days():
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [10, 10, 10, 10, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="b@c.d", days="90")
    assert result.confirmed is True
    assert result.days == "90"


def test_show_cert_form_blank_days_means_inherit():
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [10, 10, 10, 10, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="b@c.d", days="")
    assert result.confirmed is True
    assert result.days == ""


def test_show_cert_form_days_field_is_digits_only():
    # cn is read-only here, so focus starts on email: Tab once to reach days.
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [9] + [ord(c) for c in "9a0!"] + [10, 10, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="b@c.d", days="",
                                cn_readonly=True)
    assert result.confirmed is True
    assert result.days == "90"


def test_show_cert_form_refuses_zero_days():
    # Submitting "0" must keep the form open rather than closing and failing
    # later inside EasyRSA. Enter×5 tries to submit, Esc then cancels.
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [10, 10, 10, 10, 10, 27]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="b@c.d", days="0")
    assert result.confirmed is False


def test_show_cert_form_normalises_leading_zero_days():
    stdscr = _make_stdscr()
    win = _make_win(rows=20, cols=70)
    win.getch.side_effect = [10, 10, 10, 10, 10]
    with patch("curses.newwin", return_value=win):
        result = show_cert_form(stdscr, cn="bob", email="b@c.d", days="090")
    assert result.days == "90"
```

- [ ] **Step 3: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_dialogs.py -q`
Expected: FAIL — `TypeError: show_cert_form() got an unexpected keyword argument 'days'`, plus the two rewritten tests failing on keypress counts.

- [ ] **Step 4: Add the field to the dataclass and layout constants**

```python
@dataclass
class CertFormResult:
    cn: str
    email: str
    password: str
    confirmed: bool
    days: str = ""


_FORM_FIELDS  = ("cn", "email", "days", "password")
_FORM_LABELS  = {
    "cn":       "CN",
    "email":    "Email",
    "days":     "Days (blank = EasyRSA default)",
    "password": "Password",
}
_FORM_FIELD_Y = {"cn": 3, "email": 5, "days": 7, "password": 9}
```

- [ ] **Step 5: Grow the window and move the buttons**

In `show_cert_form()`, change the signature, the window height and the button row:

```python
def show_cert_form(
    stdscr,
    cn: str = "",
    email: str = "",
    password: str = "",
    days: str = "",
    cn_readonly: bool = False,
) -> CertFormResult:
```

```python
    h, w   = min(15, sh), min(62, sw)
```

```python
    _BTN_Y        = 11
```

The `curses.error` fallback near the top returns a cancelled result; leave it as is — `days` defaults to `""`.

- [ ] **Step 6: Add the field and submit validation**

Add the days field to the `fields` dict:

```python
    fields: Dict[str, InputField] = {
        "cn":       InputField(win, _FORM_FIELD_Y["cn"],       3, fw, initial=cn),
        "email":    InputField(win, _FORM_FIELD_Y["email"],    3, fw, initial=email),
        "days":     InputField(win, _FORM_FIELD_Y["days"],     3, fw, initial=days,
                               allowed=string.digits),
        "password": InputField(win, _FORM_FIELD_Y["password"], 3, fw,
                               initial=password if password else generate_password(),
                               mask=True),
    }
    focus = 0
    error = ""
```

Replace `_submit()`. It now returns `None` when the input is bad, leaving the form open:

```python
    def _submit() -> Optional[CertFormResult]:
        nonlocal error
        try:
            # Validate with the same resolver the CLI and .conf use, so what
            # counts as valid never diverges between entry points.
            days_value = resolve_cert_days(fields["days"].value, "Days")
        except ConfigError:
            # The resolver's full sentence does not fit a 62-column window.
            error = "Days must be a positive number, or blank to inherit"
            return None
        error = ""
        final_cn = cn if cn_readonly else fields["cn"].value
        return CertFormResult(
            cn=final_cn,
            email=fields["email"].value,
            password=fields["password"].value,
            days=days_value,
            confirmed=True,
        )
```

`string` is already imported at the top of the script (the password generator uses it); confirm with `grep -n "^import string" openvpncertupdate.py` and add it if absent.

- [ ] **Step 7: Show the error and handle the two submit sites**

Replace the hint block:

```python
        hint = "Tab=next  F5=regen pwd  Ctrl-G=confirm  Esc=cancel"
        hint_attr = curses.color_pair(COLOR_DISABLED)
        if error:
            hint, hint_attr = error, curses.color_pair(COLOR_ERROR)
        try:
            win.addstr(h - 2, 2, hint[:w - 4], hint_attr)
        except curses.error:
            pass
```

Replace the Ctrl-G handler:

```python
        if key == 0x07:       # Ctrl-G: immediate submit
            result = _submit()
            if result is not None:
                curses.curs_set(0)
                return result
            continue
```

And the Continue-button branch:

```python
            if key in (10, 13, curses.KEY_ENTER, ord(" ")):
                if current == _BTN_CONTINUE:
                    result = _submit()
                    if result is not None:
                        curses.curs_set(0)
                        return result
                    continue
                curses.curs_set(0)
                return CertFormResult(cn=cn, email="", password="", confirmed=False)
```

- [ ] **Step 8: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_dialogs.py -q`
Expected: PASS

- [ ] **Step 9: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 10: Commit**

```bash
git add openvpncertupdate.py tests/test_dialogs.py
git commit -m "Add Days field to the TUI cert form"
```

---

### Task 6: Wire the TUI form through to EasyRSA

**Files:**
- Modify: `openvpncertupdate.py` — `CursesApp._process_cert()` (APP section, ~line 1165-1210)
- Test: `tests/test_app_reissue.py`

**Interfaces:**
- Consumes: `show_cert_form(days=...)` and `CertFormResult.days` (Task 5), `build_client_full(days=...)` (Task 2), module global `CERT_DAYS` (Task 1).

- [ ] **Step 1: Write the failing tests**

Add to `tests/test_app_reissue.py`:

```python
def test_tui_seeds_days_field_from_cert_days(monkeypatch):
    import openvpncertupdate as m
    _patch_workflow(monkeypatch, cert_file_present=True)
    monkeypatch.setattr("openvpncertupdate.CERT_DAYS", "90")
    CursesApp()._process_cert(_stdscr(), "y.kuts", "", is_renewal=True)
    assert m.show_cert_form.call_args.kwargs["days"] == "90"


def test_tui_forwards_form_days_to_build_client_full(monkeypatch):
    mocks = _patch_workflow(monkeypatch, cert_file_present=True)
    monkeypatch.setattr(
        "openvpncertupdate.show_cert_form",
        MagicMock(return_value=CertFormResult(
            cn="y.kuts", email="", password="Testpass1234567890abcdefgh",
            days="30", confirmed=True)))
    CursesApp()._process_cert(_stdscr(), "y.kuts", "", is_renewal=True)
    assert mocks["build_client_full"].call_args.kwargs["days"] == "30"
```

`_patch_workflow` already patches `show_cert_form`; the second test replaces that patch with one returning a `days` value. Import `CertFormResult` at the top of the file alongside `CursesApp`.

- [ ] **Step 2: Run tests to verify they fail**

Run: `python3 -m pytest tests/test_app_reissue.py -k days -q`
Expected: FAIL — `KeyError: 'days'` on the `show_cert_form` kwargs, and on `build_client_full`'s.

- [ ] **Step 3: Seed the form and forward the result**

In `_process_cert()`, change the form call:

```python
        form = show_cert_form(stdscr, cn=cn, email=email, days=CERT_DAYS,
                              cn_readonly=is_renewal)
```

And the build call:

```python
            build_client_full(EASYRSA_DIR, EASYRSA_PKI_DIR,
                              final_cn, form.password, CA_PASSPHRASE,
                              email=form.email, days=form.days)
```

- [ ] **Step 4: Run tests to verify they pass**

Run: `python3 -m pytest tests/test_app_reissue.py -q`
Expected: PASS

- [ ] **Step 5: Run the full suite**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 6: Verify by mutation**

Revert each of the two edits in turn (restore the original call without `days=`), confirm the matching test goes red, then restore.

Run: `python3 -m pytest tests/ -q`
Expected: PASS after restoring.

- [ ] **Step 7: Commit**

```bash
git add openvpncertupdate.py tests/test_app_reissue.py
git commit -m "Wire the TUI Days field through to build-client-full"
```

---

### Task 7: Documentation

**Files:**
- Modify: `CLAUDE.md` — CLI flags table (~line 32), Running section (~line 20), Key constraints (~line 88)

**Interfaces:**
- Consumes: everything above. No code changes.

- [ ] **Step 1: Add the flag to the CLI flags table**

After the `--email EMAIL` row:

```markdown
| `--days N` | Certificate lifetime in days for `--create`/`--reissue`; overrides `CERT_DAYS` for that run |
```

- [ ] **Step 2: Add an example to the Running section**

After the existing `--reissue` example:

```bash
python3 openvpncertupdate.py --create CN --email user@example.com --days 90
```

- [ ] **Step 3: Add a key constraint**

After the CA-passphrase bullet:

```markdown
- Certificate lifetime (`resolve_cert_days()`, run once in `main()` right after the config overrides are applied — before the `--list` early return, since it validates config and never prompts): `CERT_DAYS = "default"` or `""` → omit `--days` entirely and let EasyRSA's own `EASYRSA_CERT_EXPIRE` (from `vars`) decide; a positive number → passed as `--days=N`, normalised so `"090"` becomes `"90"`. `0`, negatives and non-numeric values raise `ConfigError` — a fast-fail mirror of EasyRSA's own gate (`Cannot use --days=0 for command build-client-full`), not a substitute for it. `--days N` overrides `CERT_DAYS` for one CLI run; the TUI's Days field overrides it per certificate. The flag is added in `build_client_full()` only, never in `_base_cmd()` — `gen-crl` reads `--days` as CRL validity
```

- [ ] **Step 4: Update the section symbol table**

In the "File layout" table, replace the EASYRSA row with:

```markdown
| EASYRSA | `EasyRSAError`, `_easyrsa_diagnostics()`, `issued_cert_path()`, `has_issued_cert()`, `revoke_issued()`, `build_client_full()`, `gen_crl()`, `copy_crl()`, `is_ca_key_encrypted()`, `resolve_ca_passphrase()`, `resolve_cert_days()` |
```

Leave the TUI WIDGETS row alone — `InputField` is already listed and its new `allowed` parameter needs no separate entry.

- [ ] **Step 5: Run the full suite one last time**

Run: `python3 -m pytest tests/ -q`
Expected: PASS

- [ ] **Step 6: Commit**

```bash
git add CLAUDE.md
git commit -m "Document CERT_DAYS and --days"
```

---

## Manual verification after Task 7

The test suite never invokes EasyRSA. Confirm the flag actually reaches it, on a machine with the PKI:

```bash
python3 openvpncertupdate.py --create testcert --email you@example.com --days 90 --no-send-email
openssl x509 -in <PKI_DIR>/issued/testcert.crt -noout -dates
```

`notAfter` minus `notBefore` should be 90 days. Then revoke the test cert:

```bash
python3 openvpncertupdate.py --revoke testcert
```