Function act_three_responder2

connectd/handshake.c:691–769

}

static struct io_plan *act_three_responder2(struct io_conn *conn,
					    struct handshake *h)
{
	u8 der[PUBKEY_CMPR_LEN];

	SUPERVERBOSE("input: 0x%s", tal_hexstr(tmpctx, &h->act3, ACT_THREE_SIZE));

	/* BOLT #8:
	 *
	 * 2. Parse the read message (`m`) into `v`, `c`, and `t`:
	 *    * where `v` is the _first_ byte of `m`, `c` is the next 49
	 *      bytes of `m`, and `t` is the last 16 bytes of `m`
	 */

	/* BOLT #8:
	 *
	 * 3. If `v` is an unrecognized handshake version, then the responder
	 *    MUST abort the connection attempt.
	 */
	if (h->act3.v != 0)
		return handshake_failed(conn, h);

	/* BOLT #8:
	 *
	 * 4. `rs = decryptWithAD(temp_k2, 1, h, c)`
	 *      * At this point, the responder has recovered the static public
	 *        key of the initiator.
	 */
	if (!decrypt(&h->temp_k, 1, &h->h, sizeof(h->h),
		     h->act3.ciphertext, sizeof(h->act3.ciphertext),
		     der, sizeof(der)))
		return handshake_failed(conn, h);

	SUPERVERBOSE("# rs=0x%s", tal_hexstr(tmpctx, der, sizeof(der)));

	if (secp256k1_ec_pubkey_parse(secp256k1_ctx, &h->their_id.pubkey,
				      der, sizeof(der)) != 1)
		return handshake_failed(conn, h);

	/* BOLT #8:
	 *
	 * 5. `h = SHA-256(h || c)`
	 *
	 */
	sha_mix_in(&h->h, h->act3.ciphertext, sizeof(h->act3.ciphertext));
	SUPERVERBOSE("# h=0x%s", tal_hexstr(tmpctx, &h->h, sizeof(h->h)));

	/* BOLT #8:
	 *
	 * 6. `se = ECDH(e.priv, rs)`
	 *      * where `e` is the responder's original ephemeral key
	 */
	if (!secp256k1_ecdh(secp256k1_ctx, h->ss->data, &h->their_id.pubkey,
			    h->e.priv.secret.data, NULL, NULL))
		return handshake_failed(conn, h);

	SUPERVERBOSE("# ss=0x%s", tal_hexstr(tmpctx, h->ss, sizeof(*h->ss)));