BST (Binary String Toolkit) - Quickly And Easily Convert Binary Strings For All Your Exploit Development Needs

The Binary String Toolkit or BST for short is a rather simple utility to convert binary strings to various formats suitable for later inclusions in source codes, such as those used to develop exploits in the security field.

Features

Dump files content to standard output in a binary string format.
Convert a plain hexadecimal input to an escaped binary string.
Output a sequence of bad characters for testing proof of concept code.
Limit the width of binary strings for better readability in source codes.
Format output in your favorite programming language's syntax.
Perform binary variable block indentation.

Dependencies

POSIX C Library
C Compiler
- GCC
- LLVM Clang
GNU Make
Git

Building
To build and install the 'bstrings' binary, simply do:

$ git clone https://github.com/e3prom/bst
$ cd bst
$ make
# by default, bstrings is installed in /usr/local/bin.
$ make install

Usage
The below example show how an assembled shellcode can be quickly dumped (-D) to standard output in a hexadecimal escaped (-x) binary string of 16 hexadecimal digits width (or 8 bytes), with Python syntax formatting and an indentation of 4 space characters:

$ bstrings --verbose -x -D lnx-execve-setreuid-x86_64 -w8 -i 4 --syntax=python
[*] Convert hexadecimal input to an escaped binary string.
[+] Binary string width is limited to 8 bytes.
[+] Output binary string using python language syntax.
[+] Indentation level set to 4 space character(s).
    shellcode =  ""
    shellcode += "\x31\xc0\x48\x89\xc7\x48\x89\xc6"
    shellcode += "\x48\x89\xc2\xb0\x71\x0f\x05\x31"
    shellcode += "\xc0\x50\x48\xbb\x2f\x62\x69\x6e"
    shellcode += "\x2f\x2f\x73\x68\x53\x48\x89\xe7"
    shellcode += "\x50\x48\x89\xe6\x57\x48\x89\xe2"
    shellcode += "\xb0\x3b\x0f\x05"

You can also use bstrings to output an automatically indented bad character sequence, and thus in your favorite programming language:

$ bstrings --verbose -b -w12 -i 4 --syntax=c -n badchar
[*] Generating bad character binary string.
[+] Binary string width is limited to 12 bytes.
    unsigned char badchar[] =
        "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c"
        "\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18"
        "\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24"
        "\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30"
        "\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c"
        "\x3d\x3e\x3f\x40\x41\x42\x43\x44\x45\x46\x47\x48"
        "\x49\x4a\x4b\x4c\x4d\x4e\x4f\x50\x51\x52\x53\x54"
        "\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f\x60"
        "\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c"
        "\x6d\x6e\x6f\x70\x71\x72\x73\x74\x75\x76\x77\x78"
        "\x79\x7a\x7b\x7c\x7d\x7e\x7f\x80\x81\x82\x83\x84"
        "\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90"
        "\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c"
        "\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8"
        "\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4"
        "\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0"
        "\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc"
        "\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8"
        "\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4"
        "\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0"
        "\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc"
        "\xfd\xfe\xff"

For a list of supported command-line options, simply execute bstrings with the '--help' switch:

$ bstrings --help
Usage: ./bstrings [OPTION]...
 Convert input to specified binary string format.

 At least one of the below options must be given:
    -D, --dump-file=FILE    Dump content of file FILE in hexadecimal format
    -x, --hex-escape        Escape input hexadecimal string
    -b, --gen-badchar       Generate a bad character sequence string

 The below switches are optional:
    -f, --file=FILE         Read input from file FILE instead of stdin
    -w, --width=BYTES       Break binary strings to specified length in bytes
    -s, --syntax=LANG       Output variable using language syntax of LANG
    -i, --indent=LENGTH     Perform indentation for given character length
    -n, --var-name=VAR      Specify binary string variable name (verbose)
    -h, --help              Display this help
       --interactive        Enter interactive mode
       --verbose            Enable verbose output
       --version            Print version information

 The below languages are supported (case-sensitive):
    C                       C Programming language
    python                  Python Programming language

Download BST