Note that ssh-keygen also segfaults. Even on 4096 bit keys: # /usr/bin/ssh-keygen -t rsa1 -b 4096 -f /etc/ssh/ssh_host_key -N '' Generating public/private rsa1 key pair. zsh: segmentation fault (core dumped) /usr/bin/ssh-keygen -t rsa1 -b 4096 -f /etc/ssh/ssh_host_key -N ''