A ssha_passwd bash function you can use to generate passwords hashed with the salted SHA method. You can use the result in an nginx htpasswd file.

ssha_passwd.bash

function ssha_passwd() {
  local clear_pass
  read -sp 'Password: ' clear_pass
  local salt="$(openssl rand -base64 3)"
  local ssha_pass=$(printf "${clear_pass}${salt}" |openssl dgst -binary -sha1 |sed 's#$#'"${salt}"'#' |base64);
  echo "{SSHA}$ssha_pass"
}