+if which openssl >/dev/null; then
+ session_mac(){ { [ $# -gt 0 ] && printf %s "$*" || cat; } | openssl dgst -sha1 -hmac "$(server_key)" -binary |slopecode; }
+else
+ # Gonzo MAC if openssl is unavailable
+ session_mac(){
+ { server_key | dd status=none bs=256 count=1 skip=1
+ { server_key | dd status=none bs=256 count=1
+ [ $# -gt 0 ] && printf %s "$*" || cat
+ } \
+ | sha256sum -;
+ } \
+ | sha256sum | cut -d\ -f1
+ }
+fi