php_PHPチュートリアルでランダムな文字列を生成する関数

関数 encrypt_str( $TXT, $KEY )
{
srand((double)microtime() * 1000000); $ENCRYPT_KEY = md5( rand( 0, 32000 ) ); $CTR = 0; $TMP = ""; $I = 0; for ( ; $I                                                                    If ( $CTR == strlen( $ENCRYPT_KEY ) )
                                                                         $CTR = 0;                                                                                       $TMP .= substr( $ENCRYPT_KEY, $CTR, 1 ).( substr( $TXT, $I, 1 ) ^ substr( $ENCRYPT_KEY, $CTR, 1 ) ); ++$CTR; }
return keyed_str( $TMP, $KEY ); }

関数 decrypt_str( $TXT, $KEY )
{
$TXT = keyed_str( $TXT, $KEY ); $TMP = ""; $I = 0; for ( ; $I                                                                    $MD5 = substr( $TXT, $I, 1 ); ++$I; $TMP .= substr( $TXT, $I, 1 ) ^ $MD5; }

$TMP を返します。 }

関数 keyed_str( $TXT, $ENCRYPT_KEY )
{
$ENCRYPT_KEY = md5( $ENCRYPT_KEY ); $CTR = 0; $TMP = ""; $I = 0;                                                                                                                                                                                                        if ( $CTR == strlen( $ENCRYPT_KEY ) )
                                                                       $CTR = 0;                                                                                       $TMP .= substr( $TXT, $I, 1 ) ^ substr( $ENCRYPT_KEY, $CTR, 1 ); ++$CTR; }

$TMP を返します。 }