Hello!
Generic way for any scenario:
#Log into CentOS sudo -i yum install epel-release yum install ipmitool modprobe ipmi_si ipmi_msghandler ipmi_devintf #actual modules may vary, this is what usualy works for me, consult man ipmitool for options ipmitool user set name 2 <username> ipmitool user set password 2 <your_password> ipmitool user enable 2 ipmitool user priv 2 4 #This might be enough, try to log into webUI with new credentials, if doesn't work proceed with following ipmitool channel info <channel_number> # try channel number 0,1,2 and so on until you stumble upon LAN channel, on the hardware we're using it's usually number 2 ipmitool channel setaccess <your_channel_number> 2 callin=on ipmi=on link=on privilege=4 #Log into WebUI with new credentials
Your case:
As far as I understand ipmi stores passwords either 16, or 20 bytes long, so you can try to calculate how many characters your password actually consists of.
Also you can use
ipmitool user list
to find out user id for your user and then change password with
ipmitool user set password <user_id> <new_password>