Refactoring

Whatsapp_Chat_Exporter/__main__.py

@@ -104,10 +104,19 @@ def main():
             key = open(options.key, "rb").read()
             db = open(options.backup, "rb").read()
             is_crypt14 = False if "crypt12" in options.backup else True
-            if not extract.decrypt_backup(db, key, msg_db, is_crypt14):
-                print("Dependencies of decrypt_backup are not "
-                      "present. For details, see README.md")
-                exit(3)
+            error = extract.decrypt_backup(db, key, msg_db, is_crypt14)
+            if error != 0:
+                if error == 1:
+                    print("Dependencies of decrypt_backup are not "
+                          "present. For details, see README.md.")
+                    exit(3)
+                elif error == 2:
+                    print("Failed when decompressing the decrypted backup."
+                          "Possibly incorrect offsets used in decryption.")
+                    exit(4)
+                else:
+                    print("Unknown error occurred.")
+                    exit(5)
         if options.wa is None:
             contact_db = "wa.db"
         else:

Whatsapp_Chat_Exporter/extract.py

@@ -37,7 +37,7 @@ def determine_day(last, current):
 
 def decrypt_backup(database, key, output, crypt14=True):
     if not support_backup:
-        return False
+        return 1
     if len(key) != 158:
         raise ValueError("The key file must be 158 bytes")
     t1 = key[30:62]
@@ -62,11 +62,11 @@ def decrypt_backup(database, key, output, crypt14=True):
     try:
         db = zlib.decompress(db_compressed)
     except zlib.error:
-        print("Decompressing failed. Possibly incorrect offsets used in decryption.")
+        return 2
     if db[0:6].upper() == b"SQLITE":
         with open(output, "wb") as f:
             f.write(db)
-        return True
+        return 0
     else:
         raise ValueError("The plaintext is not a SQLite database. Did you use the key to encrypt something...")