This patch adds DROPBEAR_RSAKEY_ARGS and DROPBEAR_DSSKEY_ARGS optional parameters to /etc/default/dropbear. The contents are simply passed to the 'dropbearkey' program when generating a host key.
The default keysize for RSA is currently 2048 bits. It takes a CortexA9 running at 700MHz between 4 and 10 seconds to calculate a keypair. The board boots Linux in about a second, but you have to wait for several seconds because of the keypair generation. This patch allows one to put the line DROPBEAR_RSAKEY_ARGS="-s 1024" into /etc/default/dropbear, and have a host key generated in about 0.2 seconds on the same CPU. This is particulary useful for read-only rootfs systems which generate a key on each boot. Signed-off-by: Mike Looijmans <[email protected]> --- meta/recipes-core/dropbear/dropbear/init | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/meta/recipes-core/dropbear/dropbear/init b/meta/recipes-core/dropbear/dropbear/init index e8fed3f..434bd6b 100755 --- a/meta/recipes-core/dropbear/dropbear/init +++ b/meta/recipes-core/dropbear/dropbear/init @@ -62,13 +62,13 @@ for t in $DROPBEAR_KEYTYPES; do if [ -f "$DROPBEAR_RSAKEY" -a ! -s "$DROPBEAR_RSAKEY" ]; then rm $DROPBEAR_RSAKEY || true fi - test -f $DROPBEAR_RSAKEY || dropbearkey -t rsa -f $DROPBEAR_RSAKEY + test -f $DROPBEAR_RSAKEY || dropbearkey -t rsa -f $DROPBEAR_RSAKEY $DROPBEAR_RSAKEY_ARGS ;; dsa) if [ -f "$DROPBEAR_DSSKEY" -a ! -s "$DROPBEAR_DSSKEY" ]; then rm $DROPBEAR_DSSKEY || true fi - test -f $DROPBEAR_DSSKEY || dropbearkey -t dss -f $DROPBEAR_DSSKEY + test -f $DROPBEAR_DSSKEY || dropbearkey -t dss -f $DROPBEAR_DSSKEY $DROPBEAR_DSSKEY_ARGS ;; esac done -- 1.9.1 -- _______________________________________________ Openembedded-core mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-core
