Linux hang when password encryption

Posted 2022-09-02 reclouds-shangri-la

When using encryption (cfglib @Secured items, dblib-disk disk encryption), the application uses SecureRandom to get random data (for key generation, etc.). In case of a virtual machine and Linux, the system entropy can be low which may result in extremely poor performance.

To avoid this, we need to enable rngd daemon (and install it first, it’s in rng-tools package).

init.d based systems (RHEL6 and older)¶

First try to start it:

/etc/init.d/rngd start

If it complains about entropy source (Starting rngd: can‘t open entropy source(tpm or intel/amd rng)), modify /etc/sysconfig/rngd to contain the following:

EXTRAOPTIONS="-r /dev/urandom" 

Then, start and enable rngd:

/etc/init.d/rngd start
chkconfig rngd on

 

Edit this section

systemd based systems (RHEL7)¶

First try to start it:

systemctl start rngd

 

If it complains about entropy source (can‘t open entropy source(tpm or intel/amd rng) in output of systemctl status rngd, do the following:

cp /usr/lib/systemd/system/rngd.service /etc/systemd/system

Then edit /etc/systemd/system/rngd.service ExecStart line to this:

ExecStart=/sbin/rngd -f -r /dev/urandom

 

Then, start and enable rngd:

systemctl start rngd
systemctl enable rngd