global: update BOLT12 quotes.

This is a final sweep to match the current BOLT12 text:

	1563d13999d342680140c693de0b9d65aa522372 ("More bolt12 test vectors.")

Only two code changes, to change the order of checks to match the bolt,
and to give a warning on decode if a path is empty.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/test/run-bolt12-encode-test.c

@@ -248,7 +248,7 @@ int main(int argc, char *argv[])
 	/* BOLT-offers #12:
 	 *   - if it includes `offer_paths`:
 	 *     - SHOULD ignore any invoice_request which does not use the path.
-	 *     - MAY set `offer_issuer_id` to the node's public key to request the invoice from.
+	 *     - MAY set `offer_issuer_id`.
 	 *   - otherwise:
 	 *      - MUST set `offer_issuer_id` to the node's public key to request the invoice from.
 	 */

common/test/run-bolt12-format-string-test.c

@@ -117,10 +117,7 @@ int main(int argc, char *argv[])
 	offer = tlv_offer_new(tmpctx);
 	/* BOLT-offers #12:
 	 * A writer of an offer:
-	 *   - MUST NOT set any tlv fields greater or equal to 80, or tlv field 0.
-	 *   - MUST set `offer_issuer_id` to the node's public key to request the invoice from.
-	 *   - MUST set `offer_description` to a complete description of the purpose
-	 *     of the payment.
+	 *   - MUST NOT set any TLV fields outside the inclusive ranges: 1 to 79 and 1000000000 to 1999999999.
 	 *   - if the chain for the invoice is not solely bitcoin:
 	 *     - MUST specify `offer_chains` the offer is valid for.
 	 *   - otherwise:
@@ -134,9 +131,12 @@ int main(int argc, char *argv[])
 	 *       - MUST specify `offer_currency` `iso4217` as an ISO 4712 three-letter code.
 	 *       - MUST specify `offer_amount` in the currency unit adjusted by the ISO 4712
 	 *         exponent (e.g. USD cents).
+	 *     - MUST set `offer_description` to a complete description of the purpose
+	 *       of the payment.
 	 *   - otherwise:
 	 *     - MUST NOT set `offer_amount`
 	 *     - MUST NOT set `offer_currency`
+	 *     - MAY set `offer_description`
 	 *   - MAY set `offer_metadata` for its own use.
 	 *   - if it supports bolt12 offer features:
 	 *     - MUST set `offer_features`.`features` to the bitmap of bolt12 features.
@@ -151,6 +151,9 @@ int main(int argc, char *argv[])
 	 *     - MAY include `offer_paths`.
 	 *   - if it includes `offer_paths`:
 	 *     - SHOULD ignore any invoice_request which does not use the path.
+	 *     - MAY set `offer_issuer_id`.
+	 *   - otherwise:
+	 *     - MUST set `offer_issuer_id` to the node's public key to request the invoice from.
 	 *   - if it sets `offer_issuer`:
 	 *     - SHOULD set it to identify the issuer of the invoice clearly.
 	 *     - if it includes a domain name:

devtools/bolt12-cli.c

@@ -459,7 +459,7 @@ static u64 get_offer_type(const char *name)
 		 *         * [`tu64`:`max`]
 		 *     1. type: 22 (`offer_issuer_id`)
 		 *     2. data:
-		 *         * [`point`:`node_id`]
+		 *         * [`point`:`id`]
 		 */
 		{ "offer_chains", 2 },
 		{ "offer_metadata", 4 },
@@ -510,7 +510,7 @@ static u64 get_offer_type(const char *name)
 		 *         * [`tu64`:`max`]
 		 *     1. type: 22 (`offer_issuer_id`)
 		 *     2. data:
-		 *         * [`point`:`node_id`]
+		 *         * [`point`:`id`]
 		 *     1. type: 80 (`invreq_chain`)
 		 *     2. data:
 		 *         * [`chain_hash`:`chain`]
@@ -583,7 +583,7 @@ static u64 get_offer_type(const char *name)
 		 *         * [`tu64`:`max`]
 		 *     1. type: 22 (`offer_issuer_id`)
 		 *     2. data:
-		 *         * [`point`:`node_id`]
+		 *         * [`point`:`id`]
 		 *     1. type: 80 (`invreq_chain`)
 		 *     2. data:
 		 *         * [`chain_hash`:`chain`]
@@ -602,6 +602,9 @@ static u64 get_offer_type(const char *name)
 		 *     1. type: 89 (`invreq_payer_note`)
 		 *     2. data:
 		 *         * [`...*utf8`:`note`]
+		 *     1. type: 90 (`invreq_paths`)
+		 *     2. data:
+		 *         * [`...*blinded_path`:`paths`]
 		 *     1. type: 160 (`invoice_paths`)
 		 *     2. data:
 		 *         * [`...*blinded_path`:`paths`]

doc/schemas/lightning-decode.json

@@ -235,6 +235,13 @@
                 }
               }
             },
+            "warning_empty_blinded_path": {
+              "added": "v24.08",
+              "type": "string",
+              "description": [
+                "The blinded path has 0 hops."
+              ]
+            },
             "offer_node_id": {
               "type": "pubkey",
               "deprecated": [

plugins/fetchinvoice.c

@@ -221,8 +221,11 @@ static struct command_result *handle_invreq_response(struct command *cmd,
 	}
 
 	/* BOLT-offers #12:
-	 *     - if `offer_node_id` or `offer_paths` are present (invoice_request for an offer):
-	 *       - MUST reject the invoice if `invoice_node_id` is not equal to the public key it sent the `invoice_request` to.
+	 * - if `offer_issuer_id` is present (invoice_request for an offer):
+	 *   - MUST reject the invoice if `invoice_node_id` is not equal to `offer_issuer_id`
+	 * - otherwise, if `offer_paths` is present (invoice_request for an offer without id):
+	 *   - MUST reject the invoice if `invoice_node_id` is not equal to the final
+	 *    `blinded_node_id` it sent the `invoice_request` to.
 	 */
 	if (!inv->invoice_node_id || !pubkey_eq(inv->offer_issuer_id, sent->issuer_key)) {
 		badfield = "invoice_node_id";
@@ -560,7 +563,7 @@ static struct command_result *try_establish(struct command *cmd,
 		target = first.pubkey;
 		/* BOLT-offers #12:
 		 *     - if `offer_issuer_id` is present (invoice_request for an offer):
-		 *       - MUST reject the invoice if `invoice_node_id` is not equal `offer_issuer_id`
+		 *       - MUST reject the invoice if `invoice_node_id` is not equal to `offer_issuer_id`
 		 *     - otherwise, if `offer_paths` is present (invoice_request for an offer without id):
 		 *       - MUST reject the invoice if `invoice_node_id` is not equal to the final `blinded_node_id` it sent the `invoice_request` to.
 		 */
@@ -1172,7 +1175,7 @@ static struct command_result *param_invreq(struct command *cmd,
 	 * The reader:
 	 *   - MUST fail the request if `invreq_payer_id` or `invreq_metadata`
 	 *     are not present.
-	 *   - MUST fail the request if any non-signature TLV fields are outside the inclusive ranges: 0 to 159 and 1000000000 to 2999999999.
+	 *   - MUST fail the request if any non-signature TLV fields are outside the inclusive ranges: 0 to 159 and 1000000000 to 2999999999
 	 *   - if `invreq_features` contains unknown _odd_ bits that are
 	 *     non-zero:
 	 *     - MUST ignore the bit.
@@ -1229,7 +1232,7 @@ static struct command_result *param_invreq(struct command *cmd,
 	}
 
 	/* BOLT-offers #12:
-	 *  - otherwise (no `offer_node_id` or `offer_paths`, not a response to our offer):
+	 *  - otherwise (no `offer_issuer_id` or `offer_paths`, not a response to our offer):
 	 *     - MUST fail the request if any of the following are present:
 	 *       - `offer_chains`, `offer_features` or `offer_quantity_max`.
 	 *     - MUST fail the request if `invreq_amount` is not present.
@@ -1339,7 +1342,7 @@ struct command_result *json_sendinvoice(struct command *cmd,
 
 	/* BOLT-offers #12:
 	 * - if `offer_issuer_id` is present:
-	 *   - MUST set `invoice_node_id` to `offer_issuer_id`.
+	 *   - MUST set `invoice_node_id` to the `offer_issuer_id`
 	 * - otherwise, if `offer_paths` is present:
 	 *   - MUST set `invoice_node_id` to the final `blinded_node_id` on the path it received the `invoice_request`
 	 * - otherwise:

plugins/offers.c

@@ -565,6 +565,19 @@ static bool json_add_blinded_paths(struct json_stream *js,
 		return false;
 	}
 
+	/* BOLT-offers #12:
+	 *  - if `num_hops` is 0 in any `blinded_path` in `offer_paths`:
+	 *    - MUST NOT respond to the offer.
+	 */
+	for (size_t i = 0; i < tal_count(paths); i++) {
+		if (tal_count(paths[i]->path) == 0) {
+			json_add_str_fmt(js, "warning_empty_blinded_path",
+					 "blinded path %zu has 0 hops",
+					 i);
+			return false;
+		}
+	}
+
 	return true;
 }
 
@@ -1011,6 +1024,7 @@ static void json_add_b12_invoice(struct json_stream *js,
 	/* BOLT-offers #12:
 	 * - MUST reject the invoice if `invoice_paths` is not present
 	 *   or is empty.
+	 * - MUST reject the invoice if `num_hops` is 0 in any `blinded_path` in `invoice_paths`.
 	 * - MUST reject the invoice if `invoice_blindedpay` is not present.
 	 * - MUST reject the invoice if `invoice_blindedpay` does not contain
 	 *   exactly one `blinded_payinfo` per `invoice_paths`.`blinded_path`.

plugins/offers_inv_hook.c

@@ -136,13 +136,11 @@ static struct command_result *listinvreqs_done(struct command *cmd,
 	 *   - if the invoice is a response to an `invoice_request`:
 	 *     - MUST reject the invoice if all fields in ranges 0 to 159 and 1000000000 to 2999999999 (inclusive) do not exactly match the `invoice_request`.
 	 *     - if `offer_issuer_id` is present (invoice_request for an offer):
-	 *       - MUST reject the invoice if `invoice_node_id` is not equal to `offer_issuer_id`.
+	 *       - MUST reject the invoice if `invoice_node_id` is not equal to `offer_issuer_id`
 	 *     - otherwise, if `offer_paths` is present (invoice_request for an offer without id):
 	 *      - MUST reject the invoice if `invoice_node_id` is not equal to the final `blinded_node_id` it sent the `invoice_request` to.
 	 *     - otherwise (invoice_request without an offer):
 	 *       - MAY reject the invoice if it cannot confirm that `invoice_node_id` is correct, out-of-band.
-	 *
-	 *   - otherwise: (a invoice presented without being requested, eg. scanned by user):
 	 */
 
 	/* Since the invreq_id hashes all fields in those ranges, we know it matches */
@@ -317,26 +315,23 @@ struct command_result *handle_invoice(struct command *cmd,
 	 * A reader of an invoice:
 	 *...
 	 *  - MUST reject the invoice if `invoice_paths` is not present or is empty.
+	 *  - MUST reject the invoice if `num_hops` is 0 in any `blinded_path` in `invoice_paths`.
 	 *  - MUST reject the invoice if `invoice_blindedpay` is not present.
 	 *  - MUST reject the invoice if `invoice_blindedpay` does not contain exactly one `blinded_payinfo` per `invoice_paths`.`blinded_path`.
 	 */
 	if (!inv->inv->invoice_paths)
 		return fail_inv(cmd, inv, "Missing invoice_paths");
+	for (size_t i = 0; i < tal_count(inv->inv->invoice_paths); i++) {
+		if (tal_count(inv->inv->invoice_paths[i]->path) == 0)
+			return fail_inv(cmd, inv, "Empty path in invoice_paths");
+	}
 	if (!inv->inv->invoice_blindedpay)
 		return fail_inv(cmd, inv, "Missing invoice_blindedpay");
 	if (tal_count(inv->inv->invoice_blindedpay)
 	    != tal_count(inv->inv->invoice_paths))
 		return fail_inv(cmd, inv,
 				"Mismatch between invoice_blindedpay and invoice_paths");
 
-	/* BOLT-offers #12:
-	 *   - MUST reject the invoice if `num_hops` is 0 in any `blinded_path` in `invoice_paths`.
-	 */
-	for (size_t i = 0; i < tal_count(inv->inv->invoice_paths); i++) {
-		if (tal_count(inv->inv->invoice_paths[i]->path) == 0)
-			return fail_inv(cmd, inv, "Empty path in invoice_paths");
-	}
-
 	/* BOLT-offers #12:
 	 * A reader of an invoice:
 	 *...

plugins/offers_invreq_hook.c

@@ -930,7 +930,7 @@ static struct command_result *listoffers_done(struct command *cmd,
 
 	/* BOLT-offers #12:
 	 *   - if `offer_issuer_id` is present:
-	 *     - MUST set `invoice_node_id` to `offer_issuer_id`.
+	 *     - MUST set `invoice_node_id` to the `offer_issuer_id`
 	 */
 	/* FIXME: We always provide an offer_issuer_id! */
 	ir->inv->invoice_node_id = ir->inv->offer_issuer_id;

plugins/offers_offer.c

@@ -745,7 +745,7 @@ struct command_result *json_invoicerequest(struct command *cmd,
 	/* BOLT-offers #12:
 	 * - otherwise (not responding to an offer):
 	 *...
-	 *   - MUST set `invreq_payer_id` as it would set `offer_issuer_id` for an offer.
+	 *   - MUST set `invreq_payer_id` (as it would set `offer_issuer_id` for an offer).
 	 */
 	/* FIXME: Allow invoicerequests using aliases! */
 	invreq->invreq_payer_id = tal_dup(invreq, struct pubkey, &id);