Forked from raveren/cryptographically_secure_random_strings.php
Created
December 14, 2013 06:29
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function random_text( $type = 'alnum', $length = 8 ) | |
{ | |
switch ( $type ) { | |
case 'alnum': | |
$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; | |
break; | |
case 'alpha': | |
$pool = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; | |
break; | |
case 'hexdec': | |
$pool = '0123456789abcdef'; | |
break; | |
case 'numeric': | |
$pool = '0123456789'; | |
break; | |
case 'nozero': | |
$pool = '123456789'; | |
break; | |
case 'distinct': | |
$pool = '2345679ACDEFHJKLMNPRSTUVWXYZ'; | |
break; | |
default: | |
$pool = (string) $type; | |
break; | |
} | |
$crypto_rand_secure = function ( $min, $max ) { | |
$range = $max - $min; | |
if ( $range < 0 ) return $min; // not so random... | |
$log = log( $range, 2 ); | |
$bytes = (int) ( $log / 8 ) + 1; // length in bytes | |
$bits = (int) $log + 1; // length in bits | |
$filter = (int) ( 1 << $bits ) - 1; // set all lower bits to 1 | |
do { | |
$rnd = hexdec( bin2hex( openssl_random_pseudo_bytes( $bytes ) ) ); | |
$rnd = $rnd & $filter; // discard irrelevant bits | |
} while ( $rnd >= $range ); | |
return $min + $rnd; | |
}; | |
$token = ""; | |
$max = strlen( $pool ); | |
for ( $i = 0; $i < $length; $i++ ) { | |
$token .= $pool[$crypto_rand_secure( 0, $max )]; | |
} | |
return $token; | |
} |
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