first commit

app/common.py

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+"""Validation, safe paths and Internet Archive integration."""
+import html
+import re
+import socket
+import ipaddress
+from urllib.parse import urlparse, quote, unquote, parse_qs
+from pathlib import Path, PurePosixPath
+
+FORMATS = {'xex', 'god', 'raw'}
+ARCHIVE_EXTS = ('.zip', '.7z', '.rar', '.tar', '.tar.gz', '.tgz', '.tar.xz', '.tar.bz2')
+SAFE_ID = re.compile(r'^[A-Za-z0-9][A-Za-z0-9._-]{0,150}$')
+VIMM_PAGE = re.compile(r'^/vault/[0-9]+/?$')
+
+
+def safe_title(name):
+    value = re.sub(r'[^\w .()\[\]-]+', '_', name, flags=re.UNICODE).strip(' ._')[:78]
+    return value or 'Gra'
+
+
+def normalize_magnet(value):
+    # Pasted magnet URLs often contain HTML entities, hard wraps or Markdown.
+    url = html.unescape(value).strip()
+    url = re.sub(r"(?i)^['\"`]*\*{0,2}magnet\*{0,2}:\?", 'magnet:?', url)
+    if not url.lower().startswith('magnet:?'):
+        return url
+    url = re.sub(r"\\\s*", '', url)
+    url = re.sub(r"\s+", '', url)
+    return html.unescape(url.strip("'\"`"))
+
+
+def validate_url(value):
+    url = normalize_magnet(value)
+    if url.lower().startswith('magnet:?'):
+        if len(url) > 12000:
+            raise ValueError('Link magnet jest zbyt dlugi')
+        params = parse_qs(urlparse(url).query, keep_blank_values=True)
+        xt = params.get('xt', [])
+        if not any(re.fullmatch(r'urn:btih:(?:[0-9a-fA-F]{40}|[A-Za-z2-7]{32})', item, re.I)
+                   or re.fullmatch(r'urn:btmh:1220[0-9a-fA-F]{64}', item, re.I)
+                   for item in xt):
+            raise ValueError('Nieprawidlowy hash xt w magnet (BTIH: 40 znakow HEX lub 32 Base32)')
+        return 'magnet', url
+    parsed = urlparse(url)
+    if parsed.scheme not in ('https', 'http') or not parsed.hostname or parsed.username or parsed.password:
+        raise ValueError('Podaj adres HTTP/HTTPS albo link magnet')
+    try:
+        port = parsed.port
+    except ValueError as exc:
+        raise ValueError('Niepoprawny numer portu w URL') from exc
+    if port not in (None, 80, 443):
+        raise ValueError('Niestandardowy port w URL jest niedozwolony')
+    host = parsed.hostname.lower().strip('.')
+    if host in ('localhost',) or host.endswith('.localhost') or host.endswith('.local'):
+        raise ValueError('Adres lokalny nie jest dozwolony')
+    try:
+        ip = ipaddress.ip_address(host)
+    except ValueError:
+        ip = None
+    if ip is not None and not ip.is_global:
+        raise ValueError('Adres prywatny lub zarezerwowany jest niedozwolony')
+    if host in ('vimm.net', 'www.vimm.net') and VIMM_PAGE.fullmatch(parsed.path):
+        return 'vimm', url
+    return 'url', url
+
+
+def parse_archive_id(value):
+    value = value.strip()
+    u = urlparse(value)
+    if u.scheme in ('http', 'https') and u.hostname in ('archive.org', 'www.archive.org'):
+        pieces = [unquote(x) for x in u.path.split('/') if x]
+        if len(pieces) >= 2 and pieces[0] in ('details', 'download', 'metadata'):
+            value = pieces[1]
+        else:
+            raise ValueError('Link musi wskazywac element archive.org/details/<identyfikator>')
+    if not SAFE_ID.fullmatch(value):
+        raise ValueError('Bledny identyfikator elementu Archive.org')
+    return value
+
+
+def archive_download_url(identifier, filename):
+    identifier = parse_archive_id(identifier)
+    if (not filename or filename.startswith('/') or '\\' in filename or '\x00' in filename
+            or any(p in ('..', '.') for p in PurePosixPath(filename).parts)):
+        raise ValueError('Niedozwolona sciezka pliku Archive.org')
+    return f'https://archive.org/download/{quote(identifier)}/{quote(filename, safe="/")}'
+
+
+def safe_import_file(filename, root=Path('/data/imports')):
+    # User selects from server-side imports (including subdirectories).
+    if not filename or '\\' in filename or filename.startswith('/') or '\x00' in filename:
+        raise ValueError('Niepoprawna sciezka pliku')
+    item = root.joinpath(*PurePosixPath(filename).parts)
+    if not item.resolve().is_relative_to(root.resolve()):
+        raise ValueError('Plik spoza katalogu imports')
+    if not item.is_file() or item.is_symlink():
+        raise ValueError('Wskazany plik nie istnieje')
+    return item
+
+
+def is_archive(filename):
+    name = filename.lower()
+    return name.endswith(ARCHIVE_EXTS) or bool(re.search(r'\.(?:7z|zip)\.001$', name)) or bool(re.search(r'\.part0*1\.rar$', name))
+
+
+def is_additional_volume(filename):
+    name = filename.lower()
+    return bool(re.search(r'\.(?:7z|zip)\.0*0?[2-9][0-9]*$', name) or
+                re.search(r'\.part0*[2-9][0-9]*\.rar$', name) or
+                re.search(r'\.r\d\d$', name))