note 102278 added to function.crypt

Here is an expression to generate pseudorandom salt for the CRYPT_BLOWFISH hash type: <?php $salt = substr(str_replace('+', '.', base64_encode(pack('N4', mt_rand(), mt_rand(), mt_rand(), mt_rand()))), 0, 22); ?> It is intended for use on systems where mt_getrandmax() == 2147483647. The salt created will be 128 bits in length, padded to 132 bits and then expressed in 22 base64 characters. (CRYPT_BLOWFISH only uses 128 bits for the salt, even though there are 132 bits in 22 base64 characters. If you examine the CRYPT_BLOWFISH input and output, you can see that it ignores the last four bits on input, and sets them to zero on output.) Note that the high-order bits of the four 32-bit dwords returned by mt_rand() will always be zero (since mt_getrandmax == 2^31), so only 124 of the 128 bits will be pseudorandom. I found that acceptable for my application. ---- Server IP: 69.147.83.197 Probable Submitter: 76.126.164.9 ---- Manual Page -- http://www.php.net/manual/en/function.crypt.php Edit -- https://master.php.net/note/edit/102278 Del: integrated -- https://master.php.net/note/delete/102278/integrated Del: useless -- https://master.php.net/note/delete/102278/useless Del: bad code -- https://master.php.net/note/delete/102278/bad+code Del: spam -- https://master.php.net/note/delete/102278/spam Del: non-english -- https://master.php.net/note/delete/102278/non-english Del: in docs -- https://master.php.net/note/delete/102278/in+docs Del: other reasons-- https://master.php.net/note/delete/102278 Reject -- https://master.php.net/note/reject/102278 Search -- https://master.php.net/manage/user-notes.php