When I was using PHP 5.4 I used php's crypt function with CRYPT_BLOWFISH hash type. I played a bit with parameters to match your case, and concluded that your blowfish Pre should be $2y$12$ to match your cost = 12 parameter.
You can run this script in your command line to verify the result matches (I will keep your insecure mt_rand salt in this part. More on this later)
<?php
$salt= uniqid(mt_rand(), true);
$options=['salt'=>$salt, 'cost'=>12];
$mypassword=$argv[1];
$cryptpwd=crypt($mypassword,'$2y$12$'.$salt.'$'); // PHP 5.4 style
$pwdhash=password_hash($mypassword, PASSWORD_DEFAULT, $options); // PHP 5.5+
echo "\n";
echo 'CRYPT :'. $cryptpwd;
echo "\n";
echo 'PWD HASH :'. $pwdhash;
echo "\n";
if($cryptpwd===$pwdhash) {
echo 'Hashes match!';
} else {
echo 'Hashes do not match';
}
echo "\n";
For example
php pwd.php 1q2w3e4r5t
outputs
CRYPT :$2y$12$22253563353f27f9b3292ereZv98r1iFQhItfYT0UbKaejMSJThBi
PWD HASH :$2y$12$22253563353f27f9b3292ereZv98r1iFQhItfYT0UbKaejMSJThBi
Hashes match!
@JohnConde's answer is better because is safer using a well tested library. I just wanted to see what was going below the trunk.
PD: You asked
Is there a way to get this equivalent code (below) to work in php 5.4?
Now, your code has a major weakness. You are generating salts with mt_rand. Don't ever do that. Trust the system with the salt generation and, if you really want to generate it yourself, use something like the following salt generator (I used thisone when my apps were PHP 5.4)
$Allowed_Chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789./';
$Chars_Len = 63;
$Salt_Length = 21;
$salt = "";
$Blowfish_Pre='$2y$12$';
$Blowfish_End='$';
for ($i = 0; $i < $Salt_Length; $i++) {
$salt.= $Allowed_Chars[mt_rand(0, $Chars_Len) ];
}
$bcrypt_salt = $Blowfish_Pre . $salt . $Blowfish_End;
To be honest I was sure the salt had 18 characters, but looking at my old code, it's done with 21 :)
