offers: remove backwards-compatiblity invoice_request signatures.

We changed the field name in v0.11.0, so this breaks compat with
v0.10.2.

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

lightningd/offer.c

@@ -473,11 +473,6 @@ static struct command_result *json_createinvoicerequest(struct command *cmd,
 	invreq->fields = tlv_make_fields(invreq, tlv_invoice_request);
 	merkle_tlv(invreq->fields, &merkle);
 	invreq->signature = tal(invreq, struct bip340sig);
-	if (deprecated_apis)
-		hsm_sign_b12(cmd->ld, "invoice_request", "payer_signature",
-			     &merkle, invreq->payer_info, invreq->payer_key,
-			     invreq->signature);
-	else
 	hsm_sign_b12(cmd->ld, "invoice_request", "signature",
 		     &merkle, invreq->payer_info, invreq->payer_key,
 		     invreq->signature);

plugins/fetchinvoice.c

@@ -1196,9 +1196,6 @@ force_payer_secret(struct command *cmd,
 			   "Could not remarshall invreq %s", tal_hex(tmpctx, msg));
 
 	merkle_tlv(sent->invreq->fields, &merkle);
-	if (deprecated_apis)
-		sighash_from_merkle("invoice_request", "payer_signature", &merkle, &sha);
-	else
 	sighash_from_merkle("invoice_request", "signature", &merkle, &sha);
 
 	sent->invreq->signature = tal(invreq, struct bip340sig);

plugins/offers.c

@@ -776,25 +776,10 @@ static void json_add_invoice_request(struct json_stream *js,
 					       "signature",
 					       invreq->payer_key,
 					       invreq->signature)) {
-			bool sig_valid;
-
-			if (deprecated_apis) {
-				/* The old name? */
-				sig_valid = bolt12_check_signature(invreq->fields,
-								   "invoice_request",
-								   "payer_signature",
-								   invreq->payer_key,
-								   invreq->signature);
-			} else {
-				sig_valid = false;
-			}
-
-			if (!sig_valid) {
 			json_add_string(js, "warning_invoice_request_invalid_signature",
 					"Bad signature");
 			valid = false;
 		}
-		}
 	} else {
 		json_add_string(js, "warning_invoice_request_missing_signature",
 				"Missing signature");

plugins/offers_invreq_hook.c

@@ -431,23 +431,11 @@ static bool check_payer_sig(struct command *cmd,
 	merkle_tlv(invreq->fields, &merkle);
 	sighash_from_merkle("invoice_request", "signature", &merkle, &sighash);
 
-	if (secp256k1_schnorrsig_verify(secp256k1_ctx,
-					sig->u8,
-					sighash.u.u8, sizeof(sighash.u.u8), &payer_key->pubkey) == 1)
-		return true;
-
-	if (!deprecated_apis)
-		return false;
-
-	/* Try old name */
-	plugin_log(cmd->plugin, LOG_DBG,
-		   "Testing invoice_request with old name 'payer_signature'");
-	sighash_from_merkle("invoice_request", "payer_signature",
-			    &merkle, &sighash);
-
 	return secp256k1_schnorrsig_verify(secp256k1_ctx,
 					   sig->u8,
-					   sighash.u.u8, sizeof(sighash.u.u8), &payer_key->pubkey) == 1;
+					   sighash.u.u8,
+					   sizeof(sighash.u.u8),
+					   &payer_key->pubkey) == 1;
 }
 
 static struct command_result *invreq_amount_by_quantity(struct command *cmd,

tests/test_pay.py

@@ -4540,20 +4540,6 @@ def test_offer(node_factory, bitcoind):
     assert 'recurrence: every 600 seconds paywindow -10 to +600 (pay proportional)\n' in output
 
 
-def test_deprecated_offer(node_factory, bitcoind):
-    """Test that we allow old invreq name `payer_signature` with deprecated_apis"""
-    l1, l2 = node_factory.line_graph(2, opts={'experimental-offers': None,
-                                              'allow-deprecated-apis': True})
-
-    offer = l2.rpc.call('offer', {'amount': 10000,
-                                  'description': 'test'})['bolt12']
-
-    inv = l1.rpc.call('fetchinvoice', {'offer': offer})['invoice']
-    l2.daemon.wait_for_log("Testing invoice_request with old name 'payer_signature'")
-
-    l1.rpc.pay(inv)
-
-
 @pytest.mark.developer("dev-no-modern-onion is DEVELOPER-only")
 def test_fetchinvoice_3hop(node_factory, bitcoind):
     l1, l2, l3, l4 = node_factory.line_graph(4, wait_for_announce=True,