hsmd: Add hsmd_validate_revocation.

mrbitcoiner · Dec 14, 2021 · fe9f426 · fe9f426
1 parent 405239e
commit fe9f426
Show file tree

Hide file tree

Showing 4 changed files with 46 additions and 0 deletions.
diff --git a/channeld/channeld.c b/channeld/channeld.c
@@ -1785,6 +1785,7 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 	struct secret old_commit_secret;
 	struct privkey privkey;
 	struct channel_id channel_id;
+	const u8 *revocation_msg;
 	struct pubkey per_commit_point, next_per_commit;
 	const struct htlc **changed_htlcs = tal_arr(msg, const struct htlc *, 0);
 
@@ -1799,6 +1800,19 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 				 "Unexpected revoke_and_ack");
 	}
 
+	/* Submit the old revocation secret to the signer so it can
+	 * independently verify that the latest state is commited. It
+	 * is also validated in this routine after the signer returns.
+	 */
+	revocation_msg = towire_hsmd_validate_revocation(tmpctx,
+							 peer->next_index[REMOTE] - 2,
+							 &old_commit_secret);
+	revocation_msg = hsm_req(tmpctx, take(revocation_msg));
+	if (!fromwire_hsmd_validate_revocation_reply(revocation_msg))
+		status_failed(STATUS_FAIL_HSM_IO,
+			      "Bad hsmd_validate_revocation_reply: %s",
+			      tal_hex(tmpctx, revocation_msg));
+
 	/* BOLT #2:
 	 *
 	 * A receiving node:

diff --git a/hsmd/hsmd.c b/hsmd/hsmd.c
@@ -641,6 +641,7 @@ static struct io_plan *handle_client(struct io_conn *conn, struct client *c)
 #endif /* DEVELOPER */
 
 	case WIRE_HSMD_SIGN_COMMITMENT_TX:
+	case WIRE_HSMD_VALIDATE_REVOCATION:
 	case WIRE_HSMD_SIGN_PENALTY_TO_US:
 	case WIRE_HSMD_SIGN_REMOTE_COMMITMENT_TX:
 	case WIRE_HSMD_SIGN_REMOTE_HTLC_TX:
@@ -676,6 +677,7 @@ static struct io_plan *handle_client(struct io_conn *conn, struct client *c)
 	case WIRE_HSMD_INIT_REPLY:
 	case WIRE_HSMSTATUS_CLIENT_BAD_REQUEST:
 	case WIRE_HSMD_SIGN_COMMITMENT_TX_REPLY:
+	case WIRE_HSMD_VALIDATE_REVOCATION_REPLY:
 	case WIRE_HSMD_SIGN_TX_REPLY:
 	case WIRE_HSMD_SIGN_OPTION_WILL_FUND_OFFER_REPLY:
 	case WIRE_HSMD_GET_PER_COMMITMENT_POINT_REPLY:

diff --git a/hsmd/hsmd_wire.csv b/hsmd/hsmd_wire.csv
@@ -107,6 +107,14 @@ msgdata,hsmd_sign_commitment_tx,remote_funding_key,pubkey,
 msgtype,hsmd_sign_commitment_tx_reply,105
 msgdata,hsmd_sign_commitment_tx_reply,sig,bitcoin_signature,
 
+# Vaidate the counterparty's revocation secret
+msgtype,hsmd_validate_revocation,36
+msgdata,hsmd_validate_revocation,revoke_num,u64,
+msgdata,hsmd_validate_revocation,per_commitment_secret,secret,
+
+# No value returned.
+msgtype,hsmd_validate_revocation_reply,136
+
 # Onchaind asks HSM to sign a spend to-us.  Four variants, since each set
 # of keys is derived differently...
 # FIXME: Have master tell hsmd the keyindex, so it can validate output!

diff --git a/hsmd/libhsmd.c b/hsmd/libhsmd.c
@@ -95,6 +95,7 @@ bool hsmd_check_client_capabilities(struct hsmd_client *client,
 
 	case WIRE_HSMD_SIGN_REMOTE_COMMITMENT_TX:
 	case WIRE_HSMD_SIGN_REMOTE_HTLC_TX:
+	case WIRE_HSMD_VALIDATE_REVOCATION:
 		return (client->capabilities & HSM_CAP_SIGN_REMOTE_TX) != 0;
 
 	case WIRE_HSMD_SIGN_MUTUAL_CLOSE_TX:
@@ -128,6 +129,7 @@ bool hsmd_check_client_capabilities(struct hsmd_client *client,
 	case WIRE_HSMD_INIT_REPLY:
 	case WIRE_HSMSTATUS_CLIENT_BAD_REQUEST:
 	case WIRE_HSMD_SIGN_COMMITMENT_TX_REPLY:
+	case WIRE_HSMD_VALIDATE_REVOCATION_REPLY:
 	case WIRE_HSMD_SIGN_TX_REPLY:
 	case WIRE_HSMD_SIGN_OPTION_WILL_FUND_OFFER_REPLY:
 	case WIRE_HSMD_GET_PER_COMMITMENT_POINT_REPLY:
@@ -1258,6 +1260,23 @@ static u8 *handle_sign_commitment_tx(struct hsmd_client *c, const u8 *msg_in)
 	return towire_hsmd_sign_commitment_tx_reply(NULL, &sig);
 }
 
+/* This stub implementation is overriden by fully validating signers
+ * that need to independently verify that the latest state is
+ * commited. */
+static u8 *handle_validate_revocation(struct hsmd_client *c, const u8 *msg_in)
+{
+	u64 revoke_num;
+	struct secret old_secret;
+
+	if (!fromwire_hsmd_validate_revocation(msg_in,
+					       &revoke_num, &old_secret))
+		return hsmd_status_malformed_request(c, msg_in);
+
+	/* Stub implementation, relies on validation in channeld. */
+
+	return towire_hsmd_validate_revocation_reply(NULL);
+}
+
 /*~ This is used when a commitment transaction is onchain, and has an HTLC
  * output paying to us (because we have the preimage); this signs that
  * transaction, which lightningd will broadcast to collect the funds. */
@@ -1431,6 +1450,8 @@ u8 *hsmd_handle_client_message(const tal_t *ctx, struct hsmd_client *client,
 		return handle_sign_penalty_to_us(client, msg);
 	case WIRE_HSMD_SIGN_COMMITMENT_TX:
 		return handle_sign_commitment_tx(client, msg);
+	case WIRE_HSMD_VALIDATE_REVOCATION:
+		return handle_validate_revocation(client, msg);
 	case WIRE_HSMD_SIGN_REMOTE_HTLC_TO_US:
 		return handle_sign_remote_htlc_to_us(client, msg);
 	case WIRE_HSMD_SIGN_DELAYED_PAYMENT_TO_US:
@@ -1447,6 +1468,7 @@ u8 *hsmd_handle_client_message(const tal_t *ctx, struct hsmd_client *client,
 	case WIRE_HSMD_INIT_REPLY:
 	case WIRE_HSMSTATUS_CLIENT_BAD_REQUEST:
 	case WIRE_HSMD_SIGN_COMMITMENT_TX_REPLY:
+	case WIRE_HSMD_VALIDATE_REVOCATION_REPLY:
 	case WIRE_HSMD_SIGN_TX_REPLY:
 	case WIRE_HSMD_SIGN_OPTION_WILL_FUND_OFFER_REPLY:
 	case WIRE_HSMD_GET_PER_COMMITMENT_POINT_REPLY: