note 92847 added to function.mcrypt-create-iv

The official documentation above is outdated and misleading. It does not match the actual behaviour of the function on PHP 5.3+. On PHP 5.3+ you may set the '$source' argument to MCRYPT_DEV_RANDOM or MCRYPT_DEV_URANDOM on ANY platform, including Windows, to get data from the host operating-system pseudorandom number generator (/dev/{random,urandom} on *nix, CryptGenRandom() on Windows). MCRYPT_DEV_RANDOM and MCRYPT_DEV_URANDOM are equivalent on Windows. The host OS PRNG is almost always the best source of pseudorandom numbers for cryptographic purposes. If you select MCRYPT_DEV_RAND the PHP mcrypt library will use a low-entropy internal PRNG which does NOT produce crypto-quality pseudorandom numbers! You SHOULD use MCRYPT_DEV_URANDOM, because attempts to read /dev/random often block. If you use MCRYPT_DEV_RANDOM your scripts will hang unpredictably when running on a *nix platform. Keep your scripts portable, even if you mainly develop for one platform: use MCRYPT_DEV_URANDOM. ---- Server IP: 209.41.74.194 Probable Submitter: 170.167.4.200 ---- Manual Page -- http://www.php.net/manual/en/function.mcrypt-create-iv.php Edit -- https://master.php.net/note/edit/92847 Del: integrated -- https://master.php.net/note/delete/92847/integrated Del: useless -- https://master.php.net/note/delete/92847/useless Del: bad code -- https://master.php.net/note/delete/92847/bad+code Del: spam -- https://master.php.net/note/delete/92847/spam Del: non-english -- https://master.php.net/note/delete/92847/non-english Del: in docs -- https://master.php.net/note/delete/92847/in+docs Del: other reasons-- https://master.php.net/note/delete/92847 Reject -- https://master.php.net/note/reject/92847 Search -- https://master.php.net/manage/user-notes.php