Simple BCrypt Implementation (PHP)

A simple implementation of the Blowfish Crypt (BCrypt) password storage mechanism in PHP.

PHP 5.5.0 onwards makes this available via the password_hash function, so this should only be used to implement support in versions prior to that

Similar To

• PHP > 5.5.0 - password_hash($pass,PASSWORD_BCRYPT);
• Python bcrypt module
• Perl Digest::Bcrypt

Details

• Language: PHP
• License: BSD-3-Clause

Snippet

function bCrypt($pass,$cost){
      $chars='./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

      // Build the beginning of the salt
      $salt=sprintf('$2a$%02d$',$cost);

      // Seed the random generator
      mt_srand();

      // Generate a random salt
      for($i=0;$i<22;$i++) $salt.=$chars[mt_srand(0,63)];

     // return the hash
    return crypt($pass,$salt);
}

Usage Example

// Set the password in a variable
$pass = 'Password';
$hash = bCrypt($pass,12);

// We've now got the hash and can store it in a db, or in a file.

// To check the password
if ($hash == crypt($pass,$hash)){
    echo "Logged in";
}else{
    echo "access denied"
}