Port PSN pkg decryption to pure Python (drop Wine requirement)

README.md

@@ -36,12 +36,14 @@ converts PlayStation 1 ISO/CUE/BIN rips into PSP `EBOOT.PBP` homebrew.
 ## Requirements
 
 - Linux + Python 3
-- `PySide6` — the only Python dependency (`pip install -r requirements.txt`)
+- `PySide6` + `pycryptodome` (`pip install -r requirements.txt`)
 - `7z` (p7zip) — used to peek/extract disc images from store archives
-- `pkg2zip` (bundled in `data/bin/`, run via Wine on Linux) — decrypts
-  NoPayStation `.pkg` files (see [NoPayStation](#4-nopaystation))
 - PPSSPP (optional) — to launch discs from the details panel
 
+NoPayStation `.pkg` files are decrypted by the bundled **pure-Python
+decryptor** (`app/pkg.py`) — no Wine or `pkg2zip` required
+(see [NoPayStation](#4-nopaystation)).
+
 ## Install
 
 ```bash
@@ -105,8 +107,10 @@ Discs are matched by hash first (most precise), then serial, then filename.
   to drawn art when they're absent.
 - `data/nps/` — NoPayStation TSV lists (cached here on first store scan; drop
   `PSP_GAMES.tsv` / `PSX_GAMES.tsv` manually to work offline).
-- `data/bin/pkg2zip.exe` — bundled `pkg2zip` binary (MIT, by mmozeiko) used to
+- `data/bin/pkg2zip.exe` — bundled `pkg2zip` binary (MIT, by mmozeiko) kept
-  decrypt NoPayStation `.pkg` files; see `data/bin/ATTRIBUTION.md`.
+  only as an optional fallback decryptor; the app normally uses its own
+  pure-Python decryptor (`app/pkg.py`) and never needs Wine.
+  See `data/bin/ATTRIBUTION.md`.
 - State dir (`~/.local/state/psp-preserve/` by default, or `$XDG_STATE_HOME/psp-preserve`):
   - `library.sqlite` — the catalog + library database.
   - `covers/` — downloaded cover cache.
@@ -276,16 +280,17 @@ next to the source selector.
 
 Requirements & behaviour:
 
-1. `pkg2zip` decrypts the `.pkg` files (they're encrypted PSN packages, not
+1. `.pkg` files are decrypted by the built-in **pure-Python decryptor**
-   ZIPs). A copy ships in `data/bin/pkg2zip.exe` and runs via **Wine** on
+   (`app/pkg.py`, powered by `pycryptodome` for speed) — no Wine and no
-   Linux — just make sure Wine is installed. You can also put a native
+   `pkg2zip` install needed. A bundled `pkg2zip.exe` is kept as a fallback
-   `pkg2zip` on `PATH` or set its path in **Settings → Store**.
+   only, and only runs if Python decryption fails and Wine is present.
 2. Set **NoPayStation output dir** in **Settings → Store** (default
    `$PSP_STATE_DIR/nps`).
-3. Downloading a PSP game writes `PSP/<TITLE_ID>/EBOOT.PBP`; a PS1 Classic
+3. Downloading a PSP game writes `PSP/<TITLE_ID>/EBOOT.PBP` (plus
-   writes `PSX/<TITLE_ID>/EBOOT.PBP`. Both then show up in the **Library**
+   `PSP-KEY.EDAT` / `CONTENT.DAT` when the package ships them); a PS1 Classic
-   (PS1 Classics under **PS1**, PSP games under **Games**) and can be copied to
+   writes `PSX/<TITLE_ID>/EBOOT.PBP` (+ `DOCUMENT.DAT` and `KEYS.BIN`). Both
-   the PSP like any other item.
+   then show up in the **Library** (PS1 Classics under **PS1**, PSP games
+   under **Games**) and can be copied to the PSP like any other item.
 4. The TSV lists are cached in `data/nps/` and refreshed on each store scan
    (drop the `.tsv` files there manually to work offline).
 

app/gui.py

@@ -1112,7 +1112,7 @@ class SettingsPage(QWidget):
         self.archive_user_edit = self._secret_row(form, "Archive.org logged-in-user:", store_archive_user)
         self.store_edit = self._dir_row(form, "Local store dir:", store_dir)
         self.nps_edit = self._dir_row(form, "NoPayStation output dir:", nps_dir)
-        self.pkg2zip_edit = self._file_row(form, "pkg2zip executable (optional):", pkg2zip_path)
+        self.pkg2zip_edit = self._file_row(form, "pkg2zip executable (optional fallback):", pkg2zip_path)
         self.tabs.addTab(page, "Store")
 
         # -- Saves ------------------------------------------------------- #

app/nopaystation.py

@@ -2,9 +2,9 @@
 
 NoPayStation publishes per-platform TSV lists (``https://nopaystation.com/tsv/``)
 with one row per downloadable PSN item. Each row links to an encrypted PSN
-``.pkg`` (a ``\\x7FPKG`` container, not a ZIP) that must be decrypted with the
+``.pkg`` (a ``\\x7FPKG`` container, not a ZIP) that is decrypted by the bundled
-``pkg2zip`` tool before it can be installed as a ``PSP/GAME/<TITLE_ID>/``
+pure-Python decryptor (``app/pkg.py``) into a ``PSP/GAME/<TITLE_ID>/``-style
-folder.
+folder — no Wine or ``pkg2zip`` required.
 """
 from __future__ import annotations
 
@@ -173,22 +173,55 @@ def _safe_folder(value: str) -> str:
     return cleaned or "PKG"
 
 
-def extract_pkg(pkg_path, title_id: str, dest_dir, pkg2zip: Path,
+def _ensure_keys_bin(folder, kind):
-                progress_cb=None, cancel_event=None) -> Path:
+    """PS1 Classics need KEYS.BIN next to EBOOT.PBP to boot on CFW (npdrm)."""
-    """Decrypt/extract a ``.pkg`` with pkg2zip into ``dest_dir/<TITLE_ID>/``.
+    if kind != "psx":
+        return
+    src = config.DATA_DIR / "loader" / "KEYS.BIN"
+    dest = Path(folder) / "KEYS.BIN"
+    if src.is_file() and not dest.exists():
+        try:
+            shutil.copy2(src, dest)
+        except OSError:
+            pass
 
-    pkg2zip extracts PSP/PSX content into a folder layout we then normalize:
+
-    the game's ``EBOOT.PBP`` (plus siblings) are copied into the destination
+def extract_pkg(pkg_path, title_id: str, dest_dir, pkg2zip: Path = None,
-    game folder. Returns the destination folder path.
+                progress_cb=None, cancel_event=None) -> Path:
+    """Decrypt/extract a ``.pkg`` into ``dest_dir/<TITLE_ID>/``.
+
+    Uses the bundled pure-Python decryptor (no Wine / pkg2zip needed); falls
+    back to pkg2zip only if that fails and a binary is available. Returns the
+    destination game folder path.
     """
+    from . import pkg as pkgmod
     from .store import TransferCancelled
 
     pkg_path = Path(pkg_path)
-    folder_name = _safe_folder(title_id)
+    dest = Path(dest_dir) / _safe_folder(title_id)
-    dest = Path(dest_dir) / folder_name
     if (dest / "EBOOT.PBP").exists():
         return dest
 
+    # 1. Pure-Python decryptor (primary).
+    try:
+        _kind, _tid, folder = pkgmod.extract(pkg_path, dest_dir, progress_cb, cancel_event)
+        _ensure_keys_bin(folder, _kind)
+        return folder
+    except TransferCancelled:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        py_exc = exc
+        log.warning("python pkg decrypt failed (%s); trying pkg2zip fallback", exc)
+
+    # 2. pkg2zip fallback (needs a binary; usually Wine + the bundled .exe).
+    if pkg2zip is None:
+        pkg2zip = find_pkg2zip()
+    if pkg2zip is None:
+        raise RuntimeError(
+            f"could not decrypt {pkg_path.name} (no pkg2zip available): {py_exc}"
+        )
+
+    folder_name = _safe_folder(title_id)
     tmp = Path(dest_dir).with_name(".nps-tmp-" + folder_name)
     if tmp.exists():
         shutil.rmtree(tmp, ignore_errors=True)
@@ -197,7 +230,7 @@ def extract_pkg(pkg_path, title_id: str, dest_dir, pkg2zip: Path,
     if progress_cb is not None:
         progress_cb("Extracting", 0.0, "")
     try:
-        cmd = _pkg2zip_cmd(pkg2zip) + ["-x", str(pkg_path)]
+        cmd = _pkg2zip_cmd(Path(pkg2zip)) + ["-x", str(pkg_path)]
         env = dict(os.environ)
         env["WINEDEBUG"] = "-all"  # silence Wine's console chatter
         proc = subprocess.Popen(

app/pkg.py

@@ -0,0 +1,257 @@
+"""Pure-Python PSP/PSX PSN ``.pkg`` decryption (no Wine / pkg2zip needed).
+
+Ports the folder-mode extraction used by pkgi-psp's depackager and pkg2zip:
+parse the ``\\x7FPKG`` header, derive the PSP AES key, AES-CTR-decrypt the file
+entries, and write the game's ``EBOOT.PBP`` (+ siblings) into a folder. The
+resulting ``EBOOT.PBP`` keeps its DATA.PSP EDAT-encrypted, so it runs on CFW
+with the ``npdrm_free`` plugin (ARK ships it) — same as pkgi-psp's install.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+
+PKG_MAGIC = 0x7F504B47
+
+# Static PSN keys (key type 1 = PSP).
+PSP_KEY = bytes.fromhex("07f2c68290b50d2c33818d709b60e62b")
+PS3_KEY = bytes.fromhex("2e7b71d7c9c9a14ea3221f188828b8f8")
+
+try:
+    from Crypto.Cipher import AES as _AES  # pycryptodome (fast)
+    _HAVE_CRYPTO = True
+except ImportError:  # noqa: BLE001
+    _HAVE_CRYPTO = False
+
+
+# --------------------------------------------------------------------------- #
+# Pure-Python AES-128 (fallback when pycryptodome is unavailable)
+# --------------------------------------------------------------------------- #
+_SBOX = bytes.fromhex(
+    "637c777bf26b6fc53001672bfed7ab76ca82c97dfa5947f0add4a2af9ca472c0"
+    "b7fd9326363ff7cc34a5e5f171d8311504c723c31896059a071280e2eb27b275"
+    "09832c1a1b6e5aa0523bd6b329e32f8453d100ed20fcb15b6acbbe394a4c58cf"
+    "d0efaafb434d338545f9027f503c9fa851a3408f929d38f5bcb6da2110fff3d2"
+    "cd0c13ec5f974417c4a77e3d645d197360814fdc222a908846eeb814de5e0bdb"
+    "e0323a0a4906245cc2d3ac629195e479e7c8376d8dd54ea96c56f4ea657aae08"
+    "ba78252e1ca6b4c6e8dd741f4bbd8b8a703eb5664803f60e613557b986c11d9e"
+    "e1f8981169d98e949b1e87e9ce5528df8ca1890dbfe6426841992d0fb054bb16"
+)
+_RCON = (0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36)
+
+
+def _key_schedule(key):
+    w = list(key)
+    for i in range(4, 44):
+        t = list(w[(i - 1) * 4:(i - 1) * 4 + 4])
+        if i % 4 == 0:
+            t = t[1:] + t[:1]
+            t = [_SBOX[b] for b in t]
+            t[0] ^= _RCON[i // 4 - 1]
+        w += [w[(i - 4) * 4 + j] ^ t[j] for j in range(4)]
+    return [bytes(w[i * 16:(i + 1) * 16]) for i in range(11)]
+
+
+def _shift_rows(s):
+    return [s[0], s[5], s[10], s[15], s[4], s[9], s[14], s[3],
+            s[8], s[13], s[2], s[7], s[12], s[1], s[6], s[11]]
+
+
+def _xtime(a):
+    a <<= 1
+    return (a ^ 0x1B) & 0xFF if a & 0x100 else a & 0xFF
+
+
+def _mix_columns(s):
+    out = [0] * 16
+    for c in range(4):
+        a0, a1, a2, a3 = s[4 * c], s[4 * c + 1], s[4 * c + 2], s[4 * c + 3]
+        out[4 * c] = _xtime(a0) ^ (_xtime(a1) ^ a1) ^ a2 ^ a3
+        out[4 * c + 1] = a0 ^ _xtime(a1) ^ (_xtime(a2) ^ a2) ^ a3
+        out[4 * c + 2] = a0 ^ a1 ^ _xtime(a2) ^ (_xtime(a3) ^ a3)
+        out[4 * c + 3] = (_xtime(a0) ^ a0) ^ a1 ^ a2 ^ _xtime(a3)
+    return out
+
+
+def _aes_encrypt_block(rk, block):
+    s = [block[i] ^ rk[0][i] for i in range(16)]
+    for rnd in range(1, 10):
+        s = [_SBOX[b] for b in s]
+        s = _shift_rows(s)
+        s = _mix_columns(s)
+        s = [s[i] ^ rk[rnd][i] for i in range(16)]
+    s = [_SBOX[b] for b in s]
+    s = _shift_rows(s)
+    s = [s[i] ^ rk[10][i] for i in range(16)]
+    return bytes(s)
+
+
+def _add128(counter, n):
+    c = bytearray(counter)
+    for i in range(15, -1, -1):
+        n += c[i]
+        c[i] = n & 0xFF
+        n >>= 8
+    return bytes(c)
+
+
+def _ctr_decrypt_py(key, iv, block_index, data):
+    """AES-CTR decrypt (pure-Python): counter = iv + block_index, +1 per block."""
+    rk = _key_schedule(key)
+    counter = _add128(iv, block_index)
+    out = bytearray()
+    for i in range(0, len(data), 16):
+        ks = _aes_encrypt_block(rk, counter)
+        out += bytes(b ^ k for b, k in zip(data[i:i + 16], ks))
+        counter = _add128(counter, 1)
+    return bytes(out)
+
+
+def _ctr_decrypt(key, iv, block_index, data):
+    """AES-CTR decrypt: 128-bit big-endian counter at ``iv + block_index``."""
+    if _HAVE_CRYPTO:
+        nonce = iv[:8]
+        init = int.from_bytes(iv[8:16], "big") + block_index
+        return _AES.new(key, _AES.MODE_CTR, nonce=nonce, initial_value=init).decrypt(data)
+    return _ctr_decrypt_py(key, iv, block_index, data)
+
+
+def _make_ctr_decryptor(key, iv, block_index):
+    """Return a streaming decryptor (callable: bytes -> bytes) for a data run."""
+    if _HAVE_CRYPTO:
+        nonce = iv[:8]
+        init = int.from_bytes(iv[8:16], "big") + block_index
+        cipher = _AES.new(key, _AES.MODE_CTR, nonce=nonce, initial_value=init)
+        return cipher.decrypt
+    rk = _key_schedule(key)
+    counter = _add128(iv, block_index)
+    state = {"rk": rk, "counter": counter}
+
+    def decrypt(chunk):
+        out = bytearray()
+        for i in range(0, len(chunk), 16):
+            ks = _aes_encrypt_block(state["rk"], state["counter"])
+            out += bytes(b ^ k for b, k in zip(chunk[i:i + 16], ks))
+            state["counter"] = _add128(state["counter"], 1)
+        return bytes(out)
+    return decrypt
+
+
+# --------------------------------------------------------------------------- #
+# PKG extraction
+# --------------------------------------------------------------------------- #
+def extract(pkg_path, dest_dir, progress_cb=None, cancel_event=None):
+    """Decrypt a PSP/PSX PSN pkg into ``dest_dir/<TITLE_ID>/``.
+
+    Returns ``(kind, title_id, folder)`` where kind is ``"psp"`` or ``"psx"``.
+    """
+    from .store import TransferCancelled
+
+    pkg_path = Path(pkg_path)
+    dest_dir = Path(dest_dir)
+
+    with open(pkg_path, "rb") as fh:
+        header = fh.read(0x100)
+    if len(header) < 0xE8 or int.from_bytes(header[0:4], "big") != PKG_MAGIC:
+        raise RuntimeError(f"not a PKG file: {pkg_path.name}")
+
+    meta_offset = int.from_bytes(header[8:12], "big")
+    meta_count = int.from_bytes(header[12:16], "big")
+    item_count = int.from_bytes(header[20:24], "big")
+    enc_offset = int.from_bytes(header[32:40], "big")
+    iv = header[0x70:0x80]
+    key_type = header[0xE7] & 7
+    title_id = header[0x37:0x40].decode("ascii", "replace").rstrip("\x00").strip() or "PKG"
+
+    content_type = 0
+    items_offset = 0
+    with open(pkg_path, "rb") as fh:
+        off = meta_offset
+        for _ in range(meta_count):
+            fh.seek(off)
+            m = fh.read(16)
+            if len(m) < 16:
+                break
+            mtype = int.from_bytes(m[0:4], "big")
+            msize = int.from_bytes(m[4:8], "big")
+            if mtype == 2:
+                content_type = int.from_bytes(m[8:12], "big")
+            elif mtype == 13:
+                items_offset = int.from_bytes(m[8:12], "big")
+            off += 8 + msize
+
+    if content_type == 6:
+        kind = "psx"
+    elif content_type in (7, 0xE, 0xF, 0x10):
+        kind = "psp"
+    else:
+        raise RuntimeError(f"unsupported NoPayStation content type 0x{content_type:x}")
+
+    if key_type != 1:
+        raise RuntimeError(f"unsupported PKG key type {key_type}")
+
+    main_key = PSP_KEY
+    ps3_key = PS3_KEY
+
+    # Decrypt the whole item table in one shot.
+    with open(pkg_path, "rb") as fh:
+        fh.seek(enc_offset + items_offset)
+        table = fh.read(item_count * 32)
+    table = _ctr_decrypt(main_key, iv, items_offset // 16, table)
+
+    entries = []
+    for i in range(item_count):
+        e = table[i * 32:(i + 1) * 32]
+        name_offset = int.from_bytes(e[0:4], "big")
+        name_size = int.from_bytes(e[4:8], "big")
+        data_offset = int.from_bytes(e[8:16], "big")
+        data_size = int.from_bytes(e[16:24], "big")
+        psp_type = e[24]
+        flags = e[27]
+        if flags in (4, 18) or data_size == 0:
+            continue
+        item_key = main_key if psp_type == 0x90 else ps3_key
+        entries.append((name_offset, name_size, data_offset, data_size, item_key))
+
+    folder = dest_dir / title_id
+    folder.mkdir(parents=True, exist_ok=True)
+    written = []
+
+    total = sum(ds for *_, ds, _ in entries) or 1
+    done = 0
+
+    with open(pkg_path, "rb") as fh:
+        for name_offset, name_size, data_offset, data_size, item_key in entries:
+            if cancel_event is not None and cancel_event.is_set():
+                raise TransferCancelled()
+            fh.seek(enc_offset + name_offset)
+            name = _ctr_decrypt(item_key, iv, name_offset // 16, fh.read(name_size))
+            name = name.split(b"\x00", 1)[0].decode("utf-8", "replace")
+            base = name.rsplit("/", 1)[-1]
+
+            if kind == "psx" and base not in ("EBOOT.PBP", "DOCUMENT.DAT"):
+                continue
+            if kind == "psp" and base not in ("EBOOT.PBP", "PSP-KEY.EDAT", "CONTENT.DAT"):
+                continue
+
+            dest = folder / base
+            decrypt = _make_ctr_decryptor(item_key, iv, data_offset // 16)
+            fh.seek(enc_offset + data_offset)
+            with open(dest, "wb") as out:
+                remaining = data_size
+                while remaining > 0:
+                    if cancel_event is not None and cancel_event.is_set():
+                        raise TransferCancelled()
+                    chunk = fh.read(min(1 << 20, remaining))
+                    if not chunk:
+                        break
+                    out.write(decrypt(chunk))
+                    remaining -= len(chunk)
+                    done += len(chunk)
+                    if progress_cb is not None:
+                        progress_cb("Extracting", min(done / total, 1.0), "")
+            written.append(dest)
+
+    if not (folder / "EBOOT.PBP").exists():
+        raise RuntimeError(f"no EBOOT.PBP found in {pkg_path.name}")
+
+    return kind, title_id, folder

app/transfers.py

@@ -469,8 +469,8 @@ class NoPayStationSource(Source):
     """Browse NoPayStation .pkg lists and install PSP/PSX PSN content.
 
     ``content_type`` is ``"psp"`` (PSP_GAMES.tsv) or ``"psx"`` (PSX_GAMES.tsv).
-    Downloading decrypts the ``.pkg`` with the ``pkg2zip`` binary and writes a
+    Downloading decrypts the ``.pkg`` with the bundled pure-Python decryptor
-    ``<TITLE_ID>/EBOOT.PBP`` game folder into ``dest_dir``.
+    and writes a ``<TITLE_ID>/EBOOT.PBP`` game folder into ``dest_dir``.
     """
 
     label = "NoPayStation"
@@ -490,12 +490,9 @@ class NoPayStationSource(Source):
         dest_dir = Path(dest_dir)
         dest_dir.mkdir(parents=True, exist_ok=True)
 
+        # The bundled Python decryptor handles PSP/PSX directly; pkg2zip is
+        # only an optional fallback if a binary happens to be configured.
         pkg2zip = nopaystation.find_pkg2zip(self.pkg2zip)
-        if pkg2zip is None:
-            raise RuntimeError(
-                "pkg2zip not found — install it (https://github.com/mmozeiko/pkg2zip) "
-                "or set its path in Settings → Store."
-            )
         title_id = item.get("title_id") or item.get("content_id") or ""
         pkg_name = re.sub(r"[^A-Za-z0-9_-]", "", title_id) or "pkg"
         tmp = Path(tempfile.mkdtemp(prefix="nps-download-"))

data/bin/ATTRIBUTION.md

@@ -1,7 +1,9 @@
 # pkg2zip
 
-The `pkg2zip.exe` binary in this folder decrypts and extracts NoPayStation
+The `pkg2zip.exe` binary in this folder is kept as an optional fallback for
-`.pkg` files (PSP / PSX / PS3 / PSVita content).
+decrypting NoPayStation `.pkg` files (PSP / PSX / PS3 / PSVita content). The
+app normally uses its own pure-Python decryptor (`app/pkg.py`) and only runs
+this binary if that fails.
 
 - Project: <https://github.com/mmozeiko/pkg2zip>
 - Author: Marcin Mikołajczak (mmozeiko)

requirements.txt

@@ -1,2 +1,3 @@
 PySide6>=6.6
 curl_cffi>=0.7
+pycryptodome>=3.20