park this for now

Author: rpatters1

src/library/general_library.lua

@@ -632,4 +632,41 @@ function library.get_default_music_font_name()
     end
 end
 
+--[[
+%crypt_musx_file_buffer
+
+Symmetrical encryption/decryption for `.musx` files. Finale `.musx` files are byte-for-byte encrypted
+gzip archives. The archives contain xml and other data for the Finale document. This function accepts
+either a buffer of encrypted text and returns plaintext or accepts plaintext and returns encrypted text.
+
+To decrypt a `.musx`,
+
+- read the `.musx` file into a buffer using binary read mode
+- pass it to this function
+- save the return buffer as `.gz` using binary write mode
+
+Reverse the process to create a `.musx` from a `.gz` file.
+
+@ buffer (string) buffer of binary data containing plaintext or encrypted text of a `.musx` file.
+: (string) buffer of binary data containing encrypted text or plaintext corresponding to the input buffer.
+]]
+function library.crypt_musx_file_buffer(buffer)
+    local state = 0x28006D45 -- this value was determined empirically
+    local result = {}
+    
+    for i = 1, #buffer do
+        -- BSD rand()
+        state = (state * 0x41c64e6d + 0x3039) & 0xFFFFFFFF  -- Simulate 32-bit overflow
+        local upper = state >> 16
+        local c = upper + math.floor(upper / 255)
+        
+        local byte = string.byte(buffer, i)
+        byte = byte ~ (c & 0xFF)  -- XOR operation on the byte
+        
+        table.insert(result, string.char(byte))
+    end
+    
+    return table.concat(result)
+end
+
 return library