spscriptpubkeyman: Check that desc allows labels before creating label destinations

Author: Eunovo

src/wallet/scriptpubkeyman.cpp

@@ -2898,18 +2898,15 @@ SilentPaymentDescriptorScriptPubKeyMan::SilentPaymentDescriptorScriptPubKeyMan(W
         throw std::runtime_error(std::string(__func__) + ": descriptor is not a Silent Payment Descriptor");
     }
 
-    // Populate m_map_label_tweaks if descriptor is Silent Payments
-    if (descriptor.descriptor->GetOutputType() == OutputType::SILENT_PAYMENT) {
-        auto sppubkey = GetSpPubKeyFrom(descriptor.descriptor);
-        if (!sppubkey.has_value()) {
-            throw std::runtime_error(std::string(__func__) + ": descriptor expansion failed");
-        }
-        auto change_label_data = bip352::CreateLabelTweak(sppubkey->scanKey, 0);
-        m_map_label_tweaks.insert(change_label_data);
-        for (int i = 1; i < descriptor.next_index; i++) {
-            // Add the other generated labelled destinations
-            m_map_label_tweaks.insert(bip352::CreateLabelTweak(sppubkey->scanKey, i));
-        }
+    auto sppubkey = GetSpPubKeyFrom(descriptor.descriptor);
+    if (!sppubkey.has_value()) {
+        throw std::runtime_error(std::string(__func__) + ": descriptor expansion failed");
+    }
+    auto change_label_data = bip352::CreateLabelTweak(sppubkey->scanKey, 0);
+    m_map_label_tweaks.insert(change_label_data);
+    for (int i = 1; i < descriptor.next_index; i++) {
+        // Add the other generated labelled destinations
+        m_map_label_tweaks.insert(bip352::CreateLabelTweak(sppubkey->scanKey, i));
     }
 }
 
@@ -2954,7 +2951,16 @@ V0SilentPaymentDestination SilentPaymentDescriptorScriptPubKeyMan::GetLabeledDes
 util::Result<CTxDestination> SilentPaymentDescriptorScriptPubKeyMan::GetNewLabeledDestination(uint64_t& index)
 {
     LOCK(cs_desc_man);
-    auto dest = GetLabeledDestination(m_wallet_descriptor.next_index);
+
+    auto sppubkey = GetSpPubKeyFrom(m_wallet_descriptor.descriptor);
+    if (!sppubkey.has_value()) {
+        throw std::runtime_error(std::string(__func__) + ": descriptor expansion failed");
+    }
+    if (!sppubkey->AllowLabels()) {
+        return util::Error{ .message=Untranslated("Failed to create new label destination. Labels not allowed") };
+    }
+
+    auto dest{GetLabeledDestination(m_wallet_descriptor.next_index)};
     index = m_wallet_descriptor.next_index; // Return the index for this destination
     m_wallet_descriptor.next_index++;
     WalletBatch(m_storage.GetDatabase()).WriteDescriptor(GetID(), m_wallet_descriptor);

test/functional/wallet_silentpayments_receiving.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+from test_framework.descriptors import descsum_create
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_approx,
@@ -44,6 +45,32 @@ def test_labels(self):
         assert_equal(wallet_txs_by_label[0]["label"], "test")
         assert_equal(wallet.getreceivedbylabel("test"), 10)
 
+        self.log.info("Check that a silent payments wallet allows labels only when the SP desc allows it")
+        allow_labels_desc = descsum_create("sp(sprtprv1qqqqqqqqq850xtnj8hk0gpg6a7kgutyne8zmy9p38qtumvq6zj2tj97ggd4n2q8g7vh8y00v7sz34mav3ckf8jw9kg2rzwqhekcp59y5hytussmtx5yvyrl8)")
+        disallow_labels_desc = descsum_create("sp(sprtprv1qqqqqqqqqr50xtnj8hk0gpg6a7kgutyne8zmy9p38qtumvq6zj2tj97ggd4n2q8g7vh8y00v7sz34mav3ckf8jw9kg2rzwqhekcp59y5hytussmtx5vlynje)")
+
+        self.nodes[0].createwallet(wallet_name="allow_labels", blank=True, silent_payment=True)
+        allow_labels_wallet = self.nodes[0].get_wallet_rpc("allow_labels")
+        assert allow_labels_wallet.importdescriptors([{
+            "desc": allow_labels_desc,
+            "active": True,
+            "next_index": 0,
+            "timestamp": "now"
+        }])[0]["success"]
+        allow_labels_wallet.getnewaddress(address_type="silent-payments", label="test")
+        assert_equal(allow_labels_wallet.listlabels(), ["test"])
+
+        self.nodes[0].createwallet(wallet_name="disallow_labels", blank=True, silent_payment=True)
+        disallow_labels_wallet = self.nodes[0].get_wallet_rpc("disallow_labels")
+        assert disallow_labels_wallet.importdescriptors([{
+            "desc": disallow_labels_desc,
+            "active": True,
+            "next_index": 0,
+            "timestamp": "now"
+        }])[0]["success"]
+        assert_raises_rpc_error(-12, "Failed to create new label destination. Labels not allowed", disallow_labels_wallet.getnewaddress, address_type="silent-payments", label="test")
+        assert_equal(disallow_labels_wallet.listlabels(), [])
+
     def test_encrypt_and_decrypt(self):
         self.log.info("Check that a silent payments wallet can be encrypted and decrypted")
         self.log.info("Create encrypted wallet")