DOKK / manpages / debian 10 / corosync / corosync-keygen.8.en
COROSYNC-KEYGEN(8) System Manager's Manual COROSYNC-KEYGEN(8)

corosync-keygen - Generate an authentication key for Corosync.

corosync-keygen [-k <filename>] [-m <randomfile>] [-s size] [-l] [-h]

If you want to configure corosync to use cryptographic techniques to ensure authenticity and privacy of the messages, you will need to generate a private key.

corosync-keygen creates this key and writes it to /etc/corosync/authkey or to file specified by -k option.

This private key must be copied to every processor in the cluster. If the private key isn't the same for every node, those nodes with nonmatching private keys will not be able to join the same configuration.

Copy the key to some security transportable storage or use ssh to transmit the key from node to node. Then install the key with the command:

unix#: install -D --group=0 --owner=0 --mode=0400 /path_to_authkey/authkey /etc/corosync/authkey

If a message "Invalid digest" appears from the corosync executive, the keys are not consistent between processors.

This specifies the fully qualified path to the shared key to create.
The default is /etc/corosync/authkey.
Random number source file. Default is /dev/urandom. As an example /dev/random may be used when really superb randomness is needed.
Size of the generated key in bytes. Default is 1024 bytes. Allowed range is <1024, 4096>.
Option is not used and it's kept only for compatibility.
Print basic usage.

# corosync-keygen
Corosync Cluster Engine Authentication key generator.
Gathering 8192 bits for key from /dev/urandom.
Writing corosync key to /etc/corosync/authkey

$ corosync-keygen -s 2048 -k /tmp/authkey
Corosync Cluster Engine Authentication key generator.
Gathering 16384 bits for key from /dev/urandom.
Writing corosync key to /tmp/authkey.

# corosync-keygen -r /dev/random
Corosync Cluster Engine Authentication key generator.
Gathering 8192 bits for key from /dev/random.
Press keys on your keyboard to generate entropy.
Press keys on your keyboard to generate entropy (7928 bits still needed).
Press keys on your keyboard to generate entropy (7880 bits still needed).

... Press keys on your keyboard to generate entropy (104 bits still needed). Press keys on your keyboard to generate entropy (56 bits still needed). Press keys on your keyboard to generate entropy (8 bits still needed). Writing corosync key to /etc/corosync/authkey.

corosync_overview(7), corosync.conf(5),

Angus Salkeld

2017-07-03