Fix ASN.1 INTEGER encoding to avoid sign-extension issues
Fix ASN.1 INTEGER encoding to avoid sign-extension issues

We can't encode 0xfefd (DTLS1_2_VERSION) as 02 02 FE FD because that is
sign-extended and becomes -259 (0xfffffefd). We have to encode a leading
zero to make it 02 03 00 FE FD instead.

Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

nmav/openconnect-mine,atyndall/openconnect,nmav/openconnect-mine,atyndall/openconnect,matlockx/openconnect,mtmiller/openconnect,liiir1985/openconnect,brandt/openconnect,cernekee/openconnect,cernekee/openconnect,mtmiller/openconnect,mtmiller/openconnect,don-johnny/openconnect,nmav/openconnect-mine,cernekee/openconnect,brandt/openconnect,atyndall/openconnect,nmav/openconnect-mine,matlockx/openconnect,mveplus/openconnect-client,cernekee/openconnect,liiir1985/openconnect,mveplus/openconnect-client,matlockx/openconnect,mveplus/openconnect-client,lins05/openconnect,brandt/openconnect,don-johnny/openconnect,don-johnny/openconnect,brandt/openconnect,matlockx/openconnect,mtmiller/openconnect,don-johnny/openconnect,atyndall/openconnect,lins05/openconnect,liiir1985/openconnect,lins05/openconnect,mveplus/openconnect-client,lins05/openconnect,liiir1985/openconnect