NAME

App::bmkpasswd - bcrypt-capable mkpasswd(1) and exported helpers

SYNOPSIS

  bmkpasswd --help
  
  ## Generate bcrypted passwords
  ## Defaults to work cost factor '08':
  bmkpasswd
  bmkpasswd --workcost='06'

  ## Use other methods:
  bmkpasswd --method='md5'
  # SHA requires Crypt::Passwd::XS or glibc2.7+
  bmkpasswd --method='sha512'
  
  ## Compare a hash:
  bmkpasswd --check=HASH

  ## Check hash generation times:
  bmkpasswd --benchmark

DESCRIPTION

App::bmkpasswd is a simple bcrypt-enabled mkpasswd. (Helper functions are also exported for use in other applications; see "EXPORTED".)

See bmkpasswd --help for usage information.

Uses Crypt::Eksblowfish::Bcrypt for bcrypted passwords. Bcrypt hashes come with a configurable work-cost factor; that allows hash generation to become configurably slower as computers get faster, thereby impeding brute-force hash generation attempts.

See http://codahale.com/how-to-safely-store-a-password/ for more on why you ought to be using bcrypt or similar "adaptive" techniques.

SHA-256 and SHA-512 are supported if available. You'll need either Crypt::Passwd::XS or a system crypt() that can handle SHA, such as glibc-2.7+ or newer FreeBSD builds.

MD5 support is fairly universal, but it is known insecure and there is really no valid excuse to be using it; it is included here for compatibility with ancient hashes.

Salts are randomly generated.

EXPORTED

You can use the exported mkpasswd and passwdcmp functions in other Perl modules/applications:

  use App::bmkpasswd qw/mkpasswd passwdcmp/;

  ## Generate a bcrypted passwd with work-cost 08:
  $bcrypted = mkpasswd($passwd);

  ## Generate a bcrypted passwd with other work-cost:
  $bcrypted = mkpasswd($passwd, 'bcrypt', '06');

  ## SHA:
  $crypted = mkpasswd($passwd, 'sha256');
  $crypted = mkpasswd($passwd, 'sha512');

  ## Compare a password against a hash
  ## passwdcmp() will return the hash if it is a match
  if ( passwdcmp($passwd, $hash) ) {
    ## Successful match
  } else {
    ## Failed match
  }

BUGS

There is currently no easy way to pass your own salt; frankly, this thing is aimed at some projects of mine where that issue is unlikely to come up and randomized is appropriate. If that's a problem, patches welcome? ;-)

AUTHOR

Jon Portnoy <avenj@cobaltirc.org>