OpenBSD Notes

Common notes for OpenBSD

configure doas #

> echo 'permit username' > /etc/doas.conf
> echo 'permit nopass keepenv root as root' >> /etc/doas.conf

renew Let's Encrypt certificates #

> acme-client x33u.org www.x33u.org

rescue system #

> boot -s
> mount -uw /
> mount /usr # if seperatly mounted
> passwd # eg
> reboot

add floating ip for Hetzner Cloud #

# edit "/etc/hostname.vio0"

# add floating ip by hand
inet alias 116.202.xxx.xxx 255.255.255.0

# add floating ip as command
> inet alias 116.202.xxx.xxx xfffffff

# enable config by running "netstart"
> sh /etc/netstart vio0

list disks #

> sysctl hw.disknames

open encrypt disk #

> bioctl -c C -l sd3a softraid0

serial c #

> TERM=vt100
> export TERM

disable “reordering libraries” #

> rcctl disable library_aslr

verify images #

# get installXX.iso|img, openbsd-70-base.pub, SHA256 and SHA256.sig
# verify checksum on openbsd
> sha256 -C SHA256
# verify checksum on linux
> sha256sum -c --ignore-missing SHA256
# verify signature
> signify -Cp openbsd-70-base.pub -x SHA256.sig install70.iso

upgrade #

## download and verify latest bsd.rd to /
> signify -C -p /etc/signify/openbsd-68-base.pub -x SHA256.sig bsd.rd

## boot bsd.rd and choose (U)pgrade
## mount storage to /mnt if there is not enough space to upgrade
...
>> OpenBSD/amd64 BOOT 3.41
boot> bsd.rd
...

## after succesfull install reboot and run these commands
> syspatch
> pkg_add -Uu
> sysmerge -d

print partition table #

> disklabel -E sd0
...
sd0> p g
OpenBSD area: 64-104856255; size: 50.0G; free: 0.0G
#                size           offset  fstype [fsize bsize   cpg]
  a:            10.0G               64  4.2BSD   2048 16384 12960 # /
  b:             2.0G         20971296    swap                    # none
  c:            50.0G                0  unused                    
  d:             3.0G         41961760  4.2BSD   2048 16384 12960 # /tmp
  e:             5.0G         25173856  4.2BSD   2048 16384 12960 # /usr
  f:             3.0G         35664288  4.2BSD   2048 16384 12960 # /home
  g:            27.0G         41961760  4.2BSD   2048 16384 12960 # /var

kvm installion vnc reverse shell #

> ssh <host_ip> -L 5902:127.0.0.1:5902

change mirror #

> edit /etc/installurl