hst=st->hash->init();
st->hash->update(hst,st->buffer.start,st->buffer.size);
st->hash->final(hst,hash);
sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
buf_append_string(&st->buffer,sig);
free(sig);
hst=st->hash->init();
st->hash->update(hst,st->buffer.start,st->buffer.size);
st->hash->final(hst,hash);
sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
buf_append_string(&st->buffer,sig);
free(sig);