From 61e32e4ef3ca487ce9ef1bb8dcd7ab722865ba41 Mon Sep 17 00:00:00 2001
From: Rossen Georgiev <rossen@rgp.io>
Date: Sat, 25 Apr 2020 14:34:38 +0100
Subject: [PATCH] add steam.utls.appcache methods to parse appcache files

Close #179
---
 CHANGES.md               |   1 +
 docs/api/steam.utils.rst |   8 ++
 requirements.txt         |   2 +-
 steam/utils/appcache.py  | 161 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 171 insertions(+), 1 deletion(-)
 create mode 100644 steam/utils/appcache.py

diff --git a/CHANGES.md b/CHANGES.md
index 15c5dd8..532d393 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,7 @@ This release brings breaking changes
 
 ### General
 
+- Added steam.utils.appcache methods for parsing appcache files
 - Replaced `cryptography` library with `pycryptodomex`
 - Updated all enums
 - Removed imports from 'steam' namespace
diff --git a/docs/api/steam.utils.rst b/docs/api/steam.utils.rst
index 48ad00f..ac01100 100644
--- a/docs/api/steam.utils.rst
+++ b/docs/api/steam.utils.rst
@@ -6,6 +6,14 @@ utils
     :undoc-members:
     :show-inheritance:
 
+utils.appache
+------------
+
+.. automodule:: steam.utils.appcache
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 utils.binary
 ------------
 
diff --git a/requirements.txt b/requirements.txt
index c54ab8a..b16c571 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 six>=1.10.0
 pycryptodomex>=3.7.0
 requests>=2.9.1,<2.22.0
-vdf>=2.0
+vdf>=3.3
 gevent>=1.3.0
 protobuf>=3.0.0
 gevent-eventemitter>=2.1
diff --git a/steam/utils/appcache.py b/steam/utils/appcache.py
new file mode 100644
index 0000000..6018823
--- /dev/null
+++ b/steam/utils/appcache.py
@@ -0,0 +1,161 @@
+""""
+Appache file parsing examples:
+
+.. code:: python
+
+    >>> from steam.utils.appcache import parse_appinfo, parse_packageinfo
+
+    >>> header, apps = parse_appinfo(open('/d/Steam/appcache/appinfo.vdf', 'rb'))
+    >>> header
+    {'magic': b"'DV\x07", 'universe': 1}
+    >>> next(apps)
+    {'appid': 5,
+     'size': 79,
+     'info_state': 1,
+     'last_updated': 1484735377,
+     'access_token': 0,
+     'sha1': b'\x87\xfaCg\x85\x80\r\xb4\x90Im\xdc}\xb4\x81\xeeQ\x8b\x825',
+     'change_number': 4603827,
+     'data': {'appinfo': {'appid': 5, 'public_only': 1}}}
+
+    >>> header, pkgs = parse_packageinfo(open('/d/Steam/appcache/packageinfo.vdf', 'rb'))
+    >>> header
+    {'magic': b"'UV\x06", 'universe': 1}
+
+    >>> next(pkgs)
+    {'packageid': 7,
+     'sha1': b's\x8b\xf7n\t\xe5 k#\xb6-\x82\xd2 \x14k@\xfeDQ',
+     'change_number': 7469765,
+     'data': {'7': {'packageid': 7,
+       'billingtype': 1,
+       'licensetype': 1,
+       'status': 0,
+       'extended': {'requirespreapproval': 'WithRedFlag'},
+       'appids': {'0': 10, '1': 80, '2': 100, '3': 254430},
+       'depotids': {'0': 0, '1': 95, '2': 101, '3': 102, '4': 103, '5': 254431},
+       'appitems': {}}}}
+
+"""
+
+import struct
+from vdf import binary_load
+
+uint32 = struct.Struct('<I')
+uint64 = struct.Struct('<Q')
+
+def parse_appinfo(fp):
+    """Parse appinfo.vdf from the Steam appcache folder
+
+    :param fp: filelike object
+    :raises: SyntaxError
+    :rtype: (:class:`dict`, :class:`Generator`)
+    :return: (header, apps iterator)
+    """
+# format:
+#   uint32   - MAGIC: "'DV\x07"
+#   uint32   - UNIVERSE: 1
+#   ---- repeated app sections ----
+#   uint32   - AppID
+#   uint32   - size
+#   uint32   - infoState
+#   uint32   - lastUpdated
+#   uint64   - accessToken
+#   20bytes  - SHA1
+#   uint32   - changeNumber
+#   variable - binary_vdf
+#   ---- end of section ---------
+#   uint32   - EOF: 0
+
+    magic = fp.read(4)
+    if magic != b"'DV\x07":
+        raise SyntaxError("Invalid magic, got %s" % repr(magic))
+
+    universe = uint32.unpack(fp.read(4))[0]
+
+    def apps_iter():
+        while True:
+            appid = uint32.unpack(fp.read(4))[0]
+
+            if appid == 0:
+                break
+
+            app = {
+                'appid': appid,
+                'size': uint32.unpack(fp.read(4))[0],
+                'info_state': uint32.unpack(fp.read(4))[0],
+                'last_updated': uint32.unpack(fp.read(4))[0],
+                'access_token': uint64.unpack(fp.read(8))[0],
+                'sha1': fp.read(20),
+                'change_number': uint32.unpack(fp.read(4))[0],
+                'data': binary_load(fp),
+            }
+
+            yield app
+
+
+    return ({
+              'magic': magic,
+              'universe': universe,
+            },
+            apps_iter()
+            )
+
+def parse_packageinfo(fp):
+    """Parse packageinfo.vdf from the Steam appcache folder
+
+    :param fp: filelike object
+    :raises: SyntaxError
+    :rtype: (:class:`dict`, :class:`Generator`)
+    :return: (header, packages iterator)
+    """
+# format:
+#   uint32   - MAGIC: "'UV\x06"
+#   uint32   - UNIVERSE: 1
+#   ---- repeated package sections ----
+#   uint32   - PackageID
+#   20bytes  - SHA1
+#   uint32   - changeNumber
+#   uint64   - token
+#   variable - binary_vdf
+#   ---- end of section ---------
+#   uint32   - EOF: 0xFFFFFFFF
+
+    magic = fp.read(4)
+    if magic != b"'UV\x06":
+        raise SyntaxError("Invalid magic, got %s" % repr(magic))
+
+    universe = uint32.unpack(fp.read(4))[0]
+
+    def pkgs_iter():
+        while True:
+            packageid = uint32.unpack(fp.read(4))[0]
+
+            if packageid == 0xFFFFFFFF:
+                break
+
+            pkg = {
+                'packageid': packageid,
+                'sha1': fp.read(20),
+                'change_number': uint32.unpack(fp.read(4))[0],
+            }
+
+            offset = fp.tell()
+
+            try:
+                pkg['data'] = binary_load(fp)
+            except:
+                # steam beta client has introduced new token field
+                # there is no indicator, so we resolve to hackery
+                fp.seek(offset)
+                pkg['token'] = uint64.unpack(fp.read(8))[0]
+                pkg['data'] = binary_load(fp)
+
+            yield pkg
+
+
+    return ({
+              'magic': magic,
+              'universe': universe,
+            },
+            pkgs_iter()
+            )