From 640acb3f86aa39177f050a262adf7db95d860125 Mon Sep 17 00:00:00 2001
From: KnugiHK <24708955+KnugiHK@users.noreply.github.com>
Date: Sat, 25 Mar 2023 18:33:22 +0800
Subject: [PATCH] Move some utility functions to a separated python file

---
 Whatsapp_Chat_Exporter/extract.py        | 37 ++------------------
 Whatsapp_Chat_Exporter/extract_iphone.py | 18 +---------
 Whatsapp_Chat_Exporter/utility.py        | 44 ++++++++++++++++++++++++
 3 files changed, 47 insertions(+), 52 deletions(-)
 create mode 100644 Whatsapp_Chat_Exporter/utility.py

diff --git a/Whatsapp_Chat_Exporter/extract.py b/Whatsapp_Chat_Exporter/extract.py
index 3c1b9f8..a565326 100644
--- a/Whatsapp_Chat_Exporter/extract.py
+++ b/Whatsapp_Chat_Exporter/extract.py
@@ -9,13 +9,11 @@ import re
 import io
 import hmac
 from pathlib import Path
-from bleach import clean as sanitize
-from markupsafe import Markup
-from datetime import datetime
-from enum import Enum
 from mimetypes import MimeTypes
 from hashlib import sha256
 from Whatsapp_Chat_Exporter.data_model import ChatStore, Message
+from Whatsapp_Chat_Exporter.utility import sanitize_except, determine_day, Crypt
+from Whatsapp_Chat_Exporter.utility import brute_force_offset, CRYPT14_OFFSETS
 
 try:
     import zlib
@@ -31,37 +29,6 @@ except ModuleNotFoundError:
 else:
     support_crypt15 = True
 
-def sanitize_except(html):
-    return Markup(sanitize(html, tags=["br"]))
-
-
-def determine_day(last, current):
-    last = datetime.fromtimestamp(last).date()
-    current = datetime.fromtimestamp(current).date()
-    if last == current:
-        return None
-    else:
-        return current
-
-CRYPT14_OFFSETS = (
-    {"iv": 67, "db": 191},
-    {"iv": 67, "db": 190},
-    {"iv": 66, "db": 99},
-    {"iv": 67, "db": 193}
-)
-
-
-class Crypt(Enum):
-    CRYPT15 = 15
-    CRYPT14 = 14
-    CRYPT12 = 12
-
-
-def brute_force_offset():
-    for iv in range(0, 200):
-        for db in range(0, 200):
-            yield iv, iv + 16, db
-
 
 def _generate_hmac_of_hmac(key_stream):
     key = hmac.new(
diff --git a/Whatsapp_Chat_Exporter/extract_iphone.py b/Whatsapp_Chat_Exporter/extract_iphone.py
index ce1fbd6..89914f0 100644
--- a/Whatsapp_Chat_Exporter/extract_iphone.py
+++ b/Whatsapp_Chat_Exporter/extract_iphone.py
@@ -6,25 +6,9 @@ import jinja2
 import os
 import shutil
 from pathlib import Path
-from bleach import clean as sanitize
-from markupsafe import Markup
 from datetime import datetime
 from mimetypes import MimeTypes
-
-APPLE_TIME = datetime.timestamp(datetime(2001, 1, 1))
-
-
-def sanitize_except(html):
-    return Markup(sanitize(html, tags=["br"]))
-
-
-def determine_day(last, current):
-    last = datetime.fromtimestamp(last).date()
-    current = datetime.fromtimestamp(current).date()
-    if last == current:
-        return None
-    else:
-        return current
+from Whatsapp_Chat_Exporter.utility import sanitize_except, determine_day, APPLE_TIME
 
 
 def messages(db, data):
diff --git a/Whatsapp_Chat_Exporter/utility.py b/Whatsapp_Chat_Exporter/utility.py
new file mode 100644
index 0000000..6adcfde
--- /dev/null
+++ b/Whatsapp_Chat_Exporter/utility.py
@@ -0,0 +1,44 @@
+from bleach import clean as sanitize
+from markupsafe import Markup
+from datetime import datetime
+from enum import Enum
+
+
+def sanitize_except(html):
+    return Markup(sanitize(html, tags=["br"]))
+
+
+def determine_day(last, current):
+    last = datetime.fromtimestamp(last).date()
+    current = datetime.fromtimestamp(current).date()
+    if last == current:
+        return None
+    else:
+        return current
+
+
+# Android Specific
+
+CRYPT14_OFFSETS = (
+    {"iv": 67, "db": 191},
+    {"iv": 67, "db": 190},
+    {"iv": 66, "db": 99},
+    {"iv": 67, "db": 193}
+)
+
+
+class Crypt(Enum):
+    CRYPT15 = 15
+    CRYPT14 = 14
+    CRYPT12 = 12
+
+
+def brute_force_offset(max_iv=200, max_db=200):
+    for iv in range(0, max_iv):
+        for db in range(0, max_db):
+            yield iv, iv + 16, db
+
+
+# iOS Specific
+
+APPLE_TIME = datetime.timestamp(datetime(2001, 1, 1))