File Transfer Protocol Version 1

Battle.net's file transfer protocol (often abbreviated BNFTP or BNFTPv1) consists of two packets: the request and the response.

To initiate a BNFTPv1 connection, BNFTP's protocol ID, 0x02, must be sent to the server before sending a request packet. The response packet is likely to be split up among multiple TCP packets.

Request Packet Structure

Type	Field	Description
UINT16	Request Length
UINT16	Protocol Version	0x100 (256)
UINT32	Platform ID	See [Product Identification]
UINT32	Product ID	See [Product Identification]
UINT32	Ad Banner ID	0 unless downloading an ad banner
UINT32	Ad Banner File Extension	0 unless downloading an ad banner
UINT32	File start position	For resuming an incomplete download
FILETIME	Filetime	if set to 0, will return the latest version of the file
STRING	Filename

Response Packet Structure

Type	Field	Description
UINT16	Header Length	Does not include the file length
UINT16	Type
UINT32	File size
UINT32	Ad Banner ID	0 unless downloading an ad banner
UINT32	Ad Banner File Extension	0 unless downloading an ad banner
FILETIME	Filetime	last modified time of the returned file
STRING	Filename
VOID	File data

The client terminates the connection after completely receiving the requested file. If the file does not exist on the server, the connection is closed immediately.

See also, BNFTPv2.