From cda9954c27fcc94db52ab5581b627e0c2a285c9b Mon Sep 17 00:00:00 2001
From: HenrikJannsen <boilingfrog@gmx.com>
Date: Wed, 21 Dec 2022 12:31:41 -0500
Subject: [PATCH] Add deterministic sorting to Inventory as proof of work check
 compares byte arrays of payload and could fail otherwise

---
 .../main/java/bisq/common/data/ByteArray.java  |  8 +++++++-
 .../p2p/services/data/inventory/Inventory.java | 18 ++++++++++++------
 .../services/data/storage/StorageService.java  |  4 ++--
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/common/src/main/java/bisq/common/data/ByteArray.java b/common/src/main/java/bisq/common/data/ByteArray.java
index c515704e4b..e43443146e 100644
--- a/common/src/main/java/bisq/common/data/ByteArray.java
+++ b/common/src/main/java/bisq/common/data/ByteArray.java
@@ -22,10 +22,11 @@
 import com.google.protobuf.ByteString;
 import lombok.Getter;
 
+import java.math.BigInteger;
 import java.util.Arrays;
 
 @Getter
-public final class ByteArray implements Proto {
+public final class ByteArray implements Proto, Comparable<ByteArray> {
     private final byte[] bytes;
 
     public ByteArray(byte[] bytes) {
@@ -57,4 +58,9 @@ public int hashCode() {
     public String toString() {
         return Hex.encode(bytes);
     }
+
+    @Override
+    public int compareTo(ByteArray o) {
+        return new BigInteger(this.getBytes()).compareTo(new BigInteger(o.getBytes()));
+    }
 }
diff --git a/network/network/src/main/java/bisq/network/p2p/services/data/inventory/Inventory.java b/network/network/src/main/java/bisq/network/p2p/services/data/inventory/Inventory.java
index 0ed08e186f..33a2407cef 100644
--- a/network/network/src/main/java/bisq/network/p2p/services/data/inventory/Inventory.java
+++ b/network/network/src/main/java/bisq/network/p2p/services/data/inventory/Inventory.java
@@ -17,6 +17,7 @@
 
 package bisq.network.p2p.services.data.inventory;
 
+import bisq.common.data.ByteArray;
 import bisq.common.proto.Proto;
 import bisq.network.p2p.services.data.DataRequest;
 import lombok.EqualsAndHashCode;
@@ -24,8 +25,10 @@
 import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Comparator;
 import java.util.List;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 @Getter
@@ -33,12 +36,15 @@
 @EqualsAndHashCode
 @Slf4j
 public final class Inventory implements Proto {
-    private final Set<? extends DataRequest> entries;
+    private final List<? extends DataRequest> entries;
     private final int numDropped;
 
-    public Inventory(Set<? extends DataRequest> entries, int numDropped) {
-        this.entries = entries;
+    public Inventory(Collection<? extends DataRequest> entries, int numDropped) {
+        this.entries = new ArrayList<>(entries);
         this.numDropped = numDropped;
+
+        // We need to sort deterministically as the data is used in the proof of work check
+        this.entries.sort(Comparator.comparing((DataRequest o) -> new ByteArray(o.serialize())));
     }
 
     public bisq.network.protobuf.Inventory toProto() {
@@ -50,9 +56,9 @@ public bisq.network.protobuf.Inventory toProto() {
 
     public static Inventory fromProto(bisq.network.protobuf.Inventory proto) {
         List<bisq.network.protobuf.DataRequest> entriesList = proto.getEntriesList();
-        Set<DataRequest> entries = entriesList.stream()
+        List<DataRequest> entries = entriesList.stream()
                 .map(DataRequest::fromProto)
-                .collect(Collectors.toSet());
+                .collect(Collectors.toList());
         return new Inventory(entries, proto.getNumDropped());
     }
 }
diff --git a/network/network/src/main/java/bisq/network/p2p/services/data/storage/StorageService.java b/network/network/src/main/java/bisq/network/p2p/services/data/storage/StorageService.java
index 7f46bccc39..9613bc0dfb 100644
--- a/network/network/src/main/java/bisq/network/p2p/services/data/storage/StorageService.java
+++ b/network/network/src/main/java/bisq/network/p2p/services/data/storage/StorageService.java
@@ -312,10 +312,10 @@ public Inventory getInventoryFromStore(DataFilter dataFilter, DataStorageService
 
     private Inventory getInventory(DataFilter dataFilter,
                                    Set<? extends Map.Entry<ByteArray, ? extends DataRequest>> entrySet) {
-        HashSet<? extends DataRequest> result = entrySet.stream()
+        Set<? extends DataRequest> result = entrySet.stream()
                 .filter(mapEntry -> !dataFilter.getFilterEntries().contains(getFilterEntry(mapEntry)))
                 .map(Map.Entry::getValue)
-                .collect(Collectors.toCollection(HashSet::new));
+                .collect(Collectors.toSet());
         return new Inventory(result, entrySet.size() - result.size());
     }