Telegram bots use fileid to download a file. How can I get this fileid from Telegram client (My Unofficial version) ? Files in mtproto have this location class that indicates their address.
File Location Parameters
- dc_id int Number of the data center holding the file
- volume_id long Server volume
- local_id int File ID
- secret long Checksum to access the file
The problem is I don't know how to generate the fileid that is appropriate for bots from File Location class.
UPDATE 1:
I've tried to do some reverse engineering. So, I've found out that there is some relation between File Location class and FileId.
It is my File Location sample address.
- id:
0// This field is only available for secret chats - access_hash:
0// This field is only available for secret chats - volume_id:
429640340(199BCA94 HEX) - secret:
-3528741004939935589(CF0764C08833409B HEX) // according to TG documentations it should be file CheckSum - local_id:
6005(1775 HEX)
And this is my according FileID to the former FileLocation class that I retrieved it from my Bot:
- FileId:
AgADBAADL6gxG06L8w0nhNO87UW3iZTKmxkABJtAM4jAZAfPdRcAAgI
It is obvious that FileID value is in Base64 format. So I've decoded it:
- HEX Value:
0200030400032FA8311B4E8BF30D2784D3BCED45B78994CA9B1900049B403388C06407CF7517000202
Now we can see the FileLocation values in this hex value:
- Unknown:
0200030400032FA8311B4E8BF30D2784D3BCED45B789 - VolumeId:
94CA9B19 HEX - Unknown:
0004 - Secret:
9B403388C06407CF HEX - local_id:
7517 Hex - Unknown:
000202
NOTE: the values are stored in Big-Endian format.
Now we need to decode Unknown values. I appreciate any effort that helps to decode these values.
