Harden Nostr tag handling

bitchat/Nostr/NostrProtocol.swift

@@ -501,6 +501,10 @@ struct NostrEvent: Codable {
             throw NostrError.invalidEvent
         }
         
+        guard Self.isWithinInboundTagLimits(tags) else {
+            throw NostrError.invalidEvent
+        }
+
         self.id = dict["id"] as? String ?? ""
         self.pubkey = pubkey
         self.created_at = createdAt
@@ -509,6 +513,17 @@ struct NostrEvent: Codable {
         self.content = content
         self.sig = dict["sig"] as? String
     }
+
+    private static func isWithinInboundTagLimits(_ tags: [[String]]) -> Bool {
+        guard tags.count <= TransportConfig.nostrMaxEventTags else { return false }
+
+        for tag in tags {
+            guard tag.count <= TransportConfig.nostrMaxEventTagValues else { return false }
+            guard tag.allSatisfy({ $0.utf8.count <= TransportConfig.nostrMaxEventTagValueBytes }) else { return false }
+        }
+
+        return true
+    }
     
     func sign(with key: P256K.Schnorr.PrivateKey) throws -> NostrEvent {
         let (eventId, eventIdHash) = try calculateEventId()

bitchat/Nostr/NostrRelayManager.swift

@@ -963,6 +963,7 @@ private enum ParsedInbound {
     
     init?(_ message: URLSessionWebSocketTask.Message) {
         guard let data = message.data,
+              data.count <= TransportConfig.nostrMaxInboundMessageBytes,
               let array = try? JSONSerialization.jsonObject(with: data) as? [Any],
               array.count >= 2,
               let type = array[0] as? String else {

bitchat/Services/MessageFormattingEngine.swift

@@ -255,8 +255,9 @@ final class MessageFormattingEngine {
         isSelf: Bool,
         isMentioned: Bool
     ) -> AttributedString {
-        // For very long content, use plain formatting to avoid expensive regex and detector work.
-        if content.isOversizedForRichFormatting() {
+        // For very long content without special tokens, use plain formatting
+        let containsCashu = containsCashuToken(content)
+        if (content.count > 4000 || content.hasVeryLongToken(threshold: 1024)) && !containsCashu {
             return formatPlainContent(content, baseColor: baseColor, isSelf: isSelf)
         }
 

bitchat/Services/TransportConfig.swift

@@ -129,6 +129,12 @@ enum TransportConfig {
     static let nostrGeohashSampleLimit: Int = 100
     static let nostrDMSubscribeLookbackSeconds: TimeInterval = 86400
 
+    // Nostr inbound event safety limits
+    static let nostrMaxInboundMessageBytes: Int = 256 * 1024
+    static let nostrMaxEventTags: Int = 64
+    static let nostrMaxEventTagValues: Int = 16
+    static let nostrMaxEventTagValueBytes: Int = 1024
+
     // Nostr helpers
     static let nostrShortKeyDisplayLength: Int = 8
     static let nostrConvKeyPrefixLength: Int = 16

bitchat/ViewModels/ChatMessageFormatter.swift

@@ -70,7 +70,12 @@ final class ChatMessageFormatter {
             let content = message.content
             let nsContent = content as NSString
             let nsLen = nsContent.length
-            if content.isOversizedForRichFormatting() {
+            let containsCashuEarly: Bool = {
+                let regex = Patterns.quickCashuPresence
+                return regex.numberOfMatches(in: content, options: [], range: NSRange(location: 0, length: nsLen)) > 0
+            }()
+
+            if (content.count > 4000 || content.hasVeryLongToken(threshold: 1024)) && !containsCashuEarly {
                 var plainStyle = AttributeContainer()
                 plainStyle.foregroundColor = baseColor
                 plainStyle.font = isSelf

bitchat/ViewModels/ChatNostrCoordinator.swift

@@ -262,8 +262,10 @@ final class ChatNostrCoordinator {
         if viewModel.deduplicationService.hasProcessedNostrEvent(event.id) { return }
         viewModel.deduplicationService.recordNostrEvent(event.id)
 
-        let tagSummary = event.tags.map { "[" + $0.joined(separator: ",") + "]" }.joined(separator: ",")
-        SecureLogger.debug("GeoTeleport: recv pub=\(event.pubkey.prefix(8))… tags=\(tagSummary)", category: .session)
+        SecureLogger.debug(
+            "GeoTeleport: recv pub=\(event.pubkey.prefix(8))… tagCount=\(event.tags.count)",
+            category: .session
+        )
 
         if viewModel.identityManager.isNostrBlocked(pubkeyHexLowercased: event.pubkey) {
             return

bitchat/Views/Components/TextMessageView.swift

@@ -22,7 +22,7 @@ struct TextMessageView: View {
             let cashuLinks = message.content.extractCashuLinks()
             let lightningLinks = message.content.extractLightningLinks()
             HStack(alignment: .top, spacing: 0) {
-                let isLong = message.content.isLongForDisplay()
+                let isLong = (message.content.count > TransportConfig.uiLongMessageLengthThreshold || message.content.hasVeryLongToken(threshold: TransportConfig.uiVeryLongTokenThreshold)) && cashuLinks.isEmpty
                 let isExpanded = expandedMessageIDs.contains(message.id)
                 Text(conversationUIModel.formatMessage(message, colorScheme: colorScheme))
                     .fixedSize(horizontal: false, vertical: true)
@@ -38,7 +38,7 @@ struct TextMessageView: View {
             }
             
             // Expand/Collapse for very long messages
-            if message.content.isLongForDisplay() {
+            if (message.content.count > TransportConfig.uiLongMessageLengthThreshold || message.content.hasVeryLongToken(threshold: TransportConfig.uiVeryLongTokenThreshold)) && cashuLinks.isEmpty {
                 let isExpanded = expandedMessageIDs.contains(message.id)
                 let labelKey = isExpanded ? LocalizedStringKey("content.message.show_less") : LocalizedStringKey("content.message.show_more")
                 Button(labelKey) {

bitchat/Views/MessageTextHelpers.swift

@@ -21,19 +21,6 @@ extension String {
         return current >= threshold
     }
 
-    // Detect if message content should be collapsed to avoid expensive unbounded layout.
-    func isLongForDisplay(
-        lengthThreshold: Int = TransportConfig.uiLongMessageLengthThreshold,
-        tokenThreshold: Int = TransportConfig.uiVeryLongTokenThreshold
-    ) -> Bool {
-        count > lengthThreshold || hasVeryLongToken(threshold: tokenThreshold)
-    }
-
-    // Detect if message content should use plain formatting to avoid expensive regex parsing.
-    func isOversizedForRichFormatting(lengthThreshold: Int = 4000, tokenThreshold: Int = 1024) -> Bool {
-        count > lengthThreshold || hasVeryLongToken(threshold: tokenThreshold)
-    }
-
     // Extract up to `max` Cashu tokens (cashuA/cashuB). Allow dot '.' and shorter lengths.
     func extractCashuLinks(max: Int = 3) -> [String] {
         let regex = MessageFormattingEngine.Patterns.cashu

bitchatTests/ChatViewModelTests.swift

@@ -606,25 +606,6 @@ struct ChatViewModelFormattingTests {
 
         #expect(String(header.characters) == "<@Alice#a1b2> ")
     }
-
-    @Test @MainActor
-    func formatMessageAsText_longCashuMessageUsesPlainFastPath() async {
-        let (viewModel, _) = makeTestableViewModel()
-        let cashu = "cashuA" + String(repeating: "a", count: 40)
-        let longContent = "hi @bob " + cashu + " " + String(repeating: "x", count: 4_100)
-        let message = BitchatMessage(
-            id: "fmt-long-cashu",
-            sender: "Alice#a1b2",
-            content: longContent,
-            timestamp: Date(timeIntervalSince1970: 1_700_010_123),
-            isRelay: false,
-            senderPeerID: PeerID(str: "00000000000000b3")
-        )
-
-        let formatted = viewModel.formatMessageAsText(message, colorScheme: .light)
-
-        #expect(String(formatted.characters) == "<@Alice#a1b2> \(longContent) [\(message.formattedTimestamp)]")
-    }
 }
 
 // MARK: - Verification Tests

bitchatTests/MessageFormattingEngineTests.swift

@@ -323,32 +323,6 @@ struct MessageFormattingEngineTests {
         // Exactly at threshold DOES trigger (uses >= comparison)
         #expect(content.hasVeryLongToken(threshold: 50))
     }
-
-    @Test func isLongForDisplay_doesNotIgnoreCashuLinks() {
-        let cashu = "cashuA" + String(repeating: "a", count: 40)
-        let content = String(repeating: "a", count: TransportConfig.uiLongMessageLengthThreshold + 1) + " " + cashu
-
-        #expect(content.extractCashuLinks().count == 1)
-        #expect(content.isLongForDisplay())
-    }
-
-    @MainActor
-    @Test func formatMessage_longCashuMessageFallsBackToPlainContentPath() {
-        let context = MockMessageFormattingContext(nickname: "carol")
-        let cashu = "cashuA" + String(repeating: "a", count: 40)
-        let longContent = "hi @bob " + cashu + " " + String(repeating: "x", count: 4_100)
-        let message = BitchatMessage(
-            id: "long-cashu",
-            sender: "alice",
-            content: longContent,
-            timestamp: Date(timeIntervalSince1970: 1_700_000_999),
-            isRelay: false
-        )
-
-        let formatted = MessageFormattingEngine.formatMessage(message, context: context, colorScheme: .light)
-
-        #expect(String(formatted.characters) == "<@alice> \(longContent) [\(message.formattedTimestamp)]")
-    }
 }
 
 @MainActor

bitchatTests/NostrProtocolTests.swift

@@ -241,6 +241,51 @@ struct NostrProtocolTests {
         #expect(!signed.isValidSignature())
     }
 
+    @Test func inboundNostrEventRejectsTooManyTags() throws {
+        var eventDict = Self.validInboundEventDict()
+        eventDict["tags"] = Array(
+            repeating: ["g", "u4pruyd"],
+            count: TransportConfig.nostrMaxEventTags + 1
+        )
+
+        #expect(throws: NostrError.invalidEvent) {
+            _ = try NostrEvent(from: eventDict)
+        }
+    }
+
+    @Test func inboundNostrEventRejectsTooManyTagValues() throws {
+        var eventDict = Self.validInboundEventDict()
+        eventDict["tags"] = [Array(
+            repeating: "value",
+            count: TransportConfig.nostrMaxEventTagValues + 1
+        )]
+
+        #expect(throws: NostrError.invalidEvent) {
+            _ = try NostrEvent(from: eventDict)
+        }
+    }
+
+    @Test func inboundNostrEventRejectsOversizedTagValues() throws {
+        var eventDict = Self.validInboundEventDict()
+        eventDict["tags"] = [[
+            "g",
+            String(repeating: "a", count: TransportConfig.nostrMaxEventTagValueBytes + 1)
+        ]]
+
+        #expect(throws: NostrError.invalidEvent) {
+            _ = try NostrEvent(from: eventDict)
+        }
+    }
+
+    @Test func inboundNostrEventAcceptsTagsWithinLimits() throws {
+        var eventDict = Self.validInboundEventDict()
+        eventDict["tags"] = [["g", "u4pruyd"], ["t", "teleport"]]
+
+        let event = try NostrEvent(from: eventDict)
+
+        #expect(event.tags.count == 2)
+    }
+
     @Test func geohashNotesSingleFilter_encodesExpectedTagShape() throws {
         let since = Date(timeIntervalSince1970: 1_234_567)
         let filter = NostrFilter.geohashNotes("u4pruyd", since: since, limit: 42)
@@ -254,6 +299,18 @@ struct NostrProtocolTests {
     }
 
     // MARK: - Helpers
+    private static func validInboundEventDict() -> [String: Any] {
+        [
+            "id": String(repeating: "0", count: 64),
+            "pubkey": String(repeating: "1", count: 64),
+            "created_at": 1_234_567,
+            "kind": NostrProtocol.EventKind.ephemeralEvent.rawValue,
+            "tags": [["g", "u4pruyd"]],
+            "content": "hello",
+            "sig": String(repeating: "2", count: 128)
+        ]
+    }
+
     private static func base64URLDecode(_ s: String) -> Data? {
         var str = s.replacingOccurrences(of: "-", with: "+").replacingOccurrences(of: "_", with: "/")
         let rem = str.count % 4