John the Ripper 是一个快速的口令破解器 ，支持多种操作系统，如Unix、DOS、Win32、BeOS和OpenVMS等。它设计的主要目的是用于检查 Unix系统的弱口令，支持几乎所有Unix平台上经crypt函数加密后的口令哈希类型，也支持Kerberos AFS和Windows NT/2000 /XP LM哈希等。目前John the Ripper更新至1.7.9版,新版主要改变如下:
    * Added optional parallelization of the MD5-based crypt(3) code with OpenMP.
    * Added optional parallelization of the bitslice DES code with OpenMP.
    * Replaced the bitslice DES key setup algorithm with a faster one, which significantly improves performance at LM hashes, as well as at DES-based crypt(3) hashes when there’s just one salt (or very few salts).
    * Optimized the DES S-box x86-64 (16-register SSE2) assembly code.
    * Added support for 10-character DES-based tripcodes (not optimized yet).
    * Added support for the “$2y$” prefix of bcrypt hashes.
    * Added two more hash table sizes (16M and 128M entries) for faster processing of very large numbers of hashes per salt (over 1M).
    * Added two pre-defined external mode variables: “abort” and “status”, which let an external mode request the current cracking session to be aborted or the status line to be displayed, respectively.
    * Made some minor optimizations to external mode function calls and virtual machine implementation of John the Ripper.
    * The “–make-charset” option now uses floating-point rather than 64-bit integer operations, which allows for larger CHARSET_settings in params.h.
    * Added runtime detection of Intel AVX and AMD XOP instruction set extensions, with optional fallback to an alternate program binary.
    * In OpenMP-enabled builds, added support for fallback to a non-OpenMP build when the requested thread count is 1.
    * Added relbench, a Perl script to compare two “john –test” benchmark runs, such as for different machines, “make” targets, C compilers, optimization options, or/and versions of John the Ripper.
    * Additional public lists of “top N passwords” have been merged into the bundled common passwords list, and some insufficiently common passwords were removed from the list.
    * Many minor enhancements and a few bug fixes were made.
工具下载：http://download.openwall.net/pub/projects/john/1.7.8/