note 68054 modified in function.mcrypt-create-iv by cmb

After profiling a rather large, dynamic website I maintain to determine the cause of intermittent freezing in execution, I found that calls to mcrypt_create_iv() using MCRYPT_DEV_RANDOM as the source consistently halted execution for anywhere from 0.2 to ~12 seconds per call, ironically at random. I'm making the assumption that the halts were caused by insufficient random input being currently available in /dev/random due to its intended function to block until enough random input is provided back to the device. I've found it to be sufficient for my needs to use a modified version of the alt_mcrypt_create_iv() function found below. Although untested, I assume using MCRYPT_DEV_URANDOM or a combination of MCRYPT_DEV_RAND with srand() would've solved the problem as well; I found out after the fact that /dev/urandom's intended function is to seamlessly provide cryptographically secure output from the random number generator when the /dev/urandom buffer was empty, and MCRYPT_DEV_RAND would simply use the same rand() function as alt_mcrypt_create_iv(). -Kevin Kaiser --was-- After profiling a rather large, dynamic website I maintain to determine the cause of intermittent freezing in execution, I found that calls to mcrypt_create_iv() using DEV_RANDOM as the source consistently halted execution for anywhere from 0.2 to ~12 seconds per call, ironically at random. I'm making the assumption that the halts were caused by insufficient random input being currently available in /dev/random due to its intended function to block until enough random input is provided back to the device. I've found it to be sufficient for my needs to use a modified version of the alt_mcrypt_create_iv() function found below. Although untested, I assume using DEV_URANDOM or a combination of DEV_RAND with srand() would've solved the problem as well; I found out after the fact that /dev/urandom's intended function is to seamlessly provide cryptographically secure output from the random number generator when the /dev/urandom buffer was empty, and DEV_RAND would simply use the same rand() function as alt_mcrypt_create_iv(). -Kevin Kaiser http://php.net/manual/en/function.mcrypt-create-iv.php