bdflib

This library provides methods to read and write Binary Dictionary Format files that can be used to represent rainbow tables.

Binary Dictionary File Format (bdf)

<BDF> = <Header><Chunk(META)><Chunk(HTBL)>[<Chunk(DTBL)>]

All u8 format are unsigned BigEndian numbers.

Header

Raw (hex) 42 44 46 01 52 41 49 4e 42 4f 57

Position	Name	Value	Meaning
0-2	Format	BDF	Indicates the bdf Format
3-4	Version	u32	The revision of the format (0x01)
4-10	to be fancy	RAINBOW	The word "Rainbow" because why not

Chunk

Position	Name	Value	Meaning
0-3	length (l)	u32	the length of the data chunk
4-7	name	ASCII	the name of the chunk
8-l	data	any	the data of the chunk
l + 1 - l + 5	crc	crc	the crc sum value of the chunk

Meta Chunk

The format of the data inside the META chunk. The data is mandatory for the file to be interpreted and the chunk should be the first chunk in the file.

Position	Name	Value	Meaning
0-3	chunk count	u32	The number of DTBL chunks in the file
4-7	entries per chunk	u32	The maximum number of Data Rows in each chunk
8-15	total number of entries	u64	The total number Data Rows in the file
16-19	compression method	ASCII/0x00000000	The name of the compression method or null bytes if none is used

Data Row

The format inside the DTBL chunk. A chunk contains multiple data rows.

Position	Name	Value	Meaning
0-3	length(lt)	u32	the total length of the data row
4-7	length (l)	u32	the length of the password string
8-l	password	UTF-8	The password string
1: l+1 - l+5	type	u32	the id of the hash function
l+6 - l+x	hash	any	the value of the hash function. The length has to be looked up by the hash functions ID
goto 1

Hash Entry

The format inside the HTBL chunk. Just like the DataRow the HashEntry is contained in the chunk multiple times.

Position	Name	Value	Meaning
0-3	ID	u32	the id of the entry that is used in the data tables
4-7	output length	u32	the length of the output of the hash function
8-11	length	u32	the length of the hash functions name
12-length	name	ASCII	the name of the hash function