put_u32
put_u32(b, seqno);
void put_u32(void *, u_int32_t)
put_u32(buf, mlen + 1);
put_u32(mlen, sshbuf_len(m));
put_u32(*stringp, handle);
#define STORE_UINT32_REVERSED(p,v) put_u32(p,v)
#define STORE_UINT32_BIG(p,v) put_u32(p, v)