poly1305_auth
poly1305_auth(expected_tag, src, aadlen + len, poly_key);
poly1305_auth(dest + aadlen + len, dest, aadlen + len,
poly1305_auth(dest + aadlen + len, dest, aadlen + len,
poly1305_auth(expected_tag, src, aadlen + len, poly_key);
void poly1305_auth(u_char out[POLY1305_TAGLEN], const u_char *m, size_t inlen,