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 |