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Harden Nostr validation and BLE announce tests (#1012)

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Co-authored-by: jack <jackjackbits@users.noreply.github.com>
This commit is contained in:
jack
2026-02-02 18:07:19 -10:00
committed by GitHub
co-authored by jack
parent 90a5e8ba9d
commit 8c7e3e7b9b
12 changed files with 283 additions and 103 deletions
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bitchat/Nostr/NostrProtocol.swift
+20
View File
@@ -528,6 +528,26 @@ struct NostrEvent: Codable {
signed.sig = signatureHex
return signed
}
/// Validate that the event ID and Schnorr signature match the content and pubkey.
/// Returns false when the signature is missing, malformed, or does not verify.
func isValidSignature() -> Bool {
guard let sig = sig,
let sigData = Data(hexString: sig),
let pubData = Data(hexString: pubkey),
sigData.count == 64,
pubData.count == 32,
let signature = try? P256K.Schnorr.SchnorrSignature(dataRepresentation: sigData),
let (expectedId, eventHash) = try? calculateEventId(),
expectedId == id
else {
return false
}
var messageBytes = [UInt8](eventHash)
let xonly = P256K.Schnorr.XonlyKey(dataRepresentation: pubData)
return xonly.isValid(signature, for: &messageBytes)
}
private func calculateEventId() throws -> (String, Data) {
let serialized = [
bitchat/Nostr/NostrRelayManager.swift
+2 -1
View File
@@ -764,7 +764,8 @@ private enum ParsedInbound {
if array.count >= 3,
let subId = array[1] as? String,
let eventDict = array[2] as? [String: Any],
let event = try? NostrEvent(from: eventDict) {
let event = try? NostrEvent(from: eventDict),
event.isValidSignature() {
self = .event(subId: subId, event: event)
return
}
bitchat/Protocols/BinaryProtocol.swift
+1
View File
@@ -343,6 +343,7 @@ struct BinaryProtocol {
}
guard payloadLength >= 0 else { return nil }
guard payloadLength <= FileTransferLimits.maxFramedFileBytes else { return nil }
guard let senderID = readData(senderIDSize) else { return nil }
bitchat/Services/BLE/BLEService.swift
+23 -21
View File
@@ -2038,26 +2038,28 @@ extension BLEService {
#if DEBUG
// Test-only helper to inject packets into the receive pipeline
extension BLEService {
func _test_handlePacket(_ packet: BitchatPacket, fromPeerID: PeerID) {
// Ensure the synthetic peer is known and marked verified for public-message tests
let normalizedID = PeerID(hexData: packet.senderID)
collectionsQueue.sync(flags: .barrier) {
if peers[normalizedID] == nil {
peers[normalizedID] = PeerInfo(
peerID: normalizedID,
nickname: "TestPeer_\(fromPeerID.id.prefix(4))",
isConnected: true,
noisePublicKey: packet.senderID,
signingPublicKey: nil,
isVerifiedNickname: true,
lastSeen: Date()
)
} else {
var p = peers[normalizedID]!
p.isConnected = true
p.isVerifiedNickname = true
p.lastSeen = Date()
peers[normalizedID] = p
func _test_handlePacket(_ packet: BitchatPacket, fromPeerID: PeerID, preseedPeer: Bool = true) {
if preseedPeer {
// Ensure the synthetic peer is known and marked verified for public-message tests
let normalizedID = PeerID(hexData: packet.senderID)
collectionsQueue.sync(flags: .barrier) {
if peers[normalizedID] == nil {
peers[normalizedID] = PeerInfo(
peerID: normalizedID,
nickname: "TestPeer_\(fromPeerID.id.prefix(4))",
isConnected: true,
noisePublicKey: packet.senderID,
signingPublicKey: nil,
isVerifiedNickname: true,
lastSeen: Date()
)
} else {
var p = peers[normalizedID]!
p.isConnected = true
p.isVerifiedNickname = true
p.lastSeen = Date()
peers[normalizedID] = p
}
}
}
handleReceivedPacket(packet, from: fromPeerID)
@@ -3839,7 +3841,7 @@ extension BLEService {
let derivedFromKey = PeerID(publicKey: announcement.noisePublicKey)
if derivedFromKey != peerID {
SecureLogger.warning("⚠️ Announce sender mismatch: derived \(derivedFromKey.id.prefix(8))… vs packet \(peerID.id.prefix(8))…", category: .security)
return
}
// Don't add ourselves as a peer
bitchat/ViewModels/Extensions/ChatViewModel+Nostr.swift
+39 -26
View File
@@ -56,6 +56,7 @@ extension ChatViewModel {
}
func subscribeNostrEvent(_ event: NostrEvent) {
guard event.isValidSignature() else { return }
guard (event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue ||
event.kind == NostrProtocol.EventKind.geohashPresence.rawValue),
!deduplicationService.hasProcessedNostrEvent(event.id)
@@ -146,13 +147,12 @@ extension ChatViewModel {
}
func subscribeGiftWrap(_ giftWrap: NostrEvent, id: NostrIdentity) {
guard giftWrap.isValidSignature() else { return }
guard !deduplicationService.hasProcessedNostrEvent(giftWrap.id) else { return }
deduplicationService.recordNostrEvent(giftWrap.id)
guard let (content, senderPubkey, rumorTs) = try? NostrProtocol.decryptPrivateMessage(giftWrap: giftWrap, recipientIdentity: id),
content.hasPrefix("bitchat1:"),
let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
let packet = BitchatPacket.from(packetData),
let packet = Self.decodeEmbeddedBitChatPacket(from: content),
packet.type == MessageType.noiseEncrypted.rawValue,
let noisePayload = NoisePayload.decode(packet.payload)
else {
@@ -254,6 +254,7 @@ extension ChatViewModel {
}
func handleNostrEvent(_ event: NostrEvent) {
guard event.isValidSignature() else { return }
// Only handle ephemeral kind 20000 or presence kind 20001 with matching tag
guard (event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue ||
event.kind == NostrProtocol.EventKind.geohashPresence.rawValue) else { return }
@@ -367,6 +368,7 @@ extension ChatViewModel {
}
func handleGiftWrap(_ giftWrap: NostrEvent, id: NostrIdentity) {
guard giftWrap.isValidSignature() else { return }
if deduplicationService.hasProcessedNostrEvent(giftWrap.id) {
return
}
@@ -380,9 +382,7 @@ extension ChatViewModel {
SecureLogger.debug("GeoDM: decrypted gift-wrap id=\(giftWrap.id.prefix(16))... from=\(senderPubkey.prefix(8))...", category: .session)
guard content.hasPrefix("bitchat1:"),
let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
let packet = BitchatPacket.from(packetData),
guard let packet = Self.decodeEmbeddedBitChatPacket(from: content),
packet.type == MessageType.noiseEncrypted.rawValue,
let payload = NoisePayload.decode(packet.payload)
else {
@@ -485,6 +485,7 @@ extension ChatViewModel {
}
func subscribeNostrEvent(_ event: NostrEvent, gh: String) {
guard event.isValidSignature() else { return }
guard (event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue ||
event.kind == NostrProtocol.EventKind.geohashPresence.rawValue) else { return }
@@ -602,6 +603,7 @@ extension ChatViewModel {
}
func processNostrMessage(_ giftWrap: NostrEvent) async {
guard giftWrap.isValidSignature() else { return }
guard let currentIdentity = try? idBridge.getCurrentNostrIdentity() else { return }
do {
@@ -619,8 +621,7 @@ extension ChatViewModel {
// Check if it's a BitChat packet embedded in the content (bitchat1:...)
if content.hasPrefix("bitchat1:") {
guard let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
let packet = BitchatPacket.from(packetData) else {
guard let packet = Self.decodeEmbeddedBitChatPacket(from: content) else {
SecureLogger.error("Failed to decode embedded BitChat packet from Nostr DM", category: .session)
return
}
@@ -631,24 +632,23 @@ extension ChatViewModel {
// Stable target ID if we know Noise key; otherwise temporary Nostr-based peer
let targetPeerID = PeerID(str: actualSenderNoiseKey?.hexEncodedString()) ?? PeerID(nostr_: senderPubkey)
if packet.type == MessageType.noiseEncrypted.rawValue {
if let payload = NoisePayload.decode(packet.payload) {
let messageTimestamp = Date(timeIntervalSince1970: TimeInterval(rumorTimestamp))
// Store Nostr mapping
await MainActor.run {
nostrKeyMapping[targetPeerID] = senderPubkey
// Handle packet types
switch payload.type {
case .privateMessage:
handlePrivateMessage(payload, senderPubkey: senderPubkey, convKey: targetPeerID, id: currentIdentity, messageTimestamp: messageTimestamp)
case .delivered:
handleDelivered(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
case .readReceipt:
handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
case .verifyChallenge, .verifyResponse:
break
}
if packet.type == MessageType.noiseEncrypted.rawValue,
let payload = NoisePayload.decode(packet.payload) {
let messageTimestamp = Date(timeIntervalSince1970: TimeInterval(rumorTimestamp))
// Store Nostr mapping
await MainActor.run {
nostrKeyMapping[targetPeerID] = senderPubkey
// Handle packet types
switch payload.type {
case .privateMessage:
handlePrivateMessage(payload, senderPubkey: senderPubkey, convKey: targetPeerID, id: currentIdentity, messageTimestamp: messageTimestamp)
case .delivered:
handleDelivered(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
case .readReceipt:
handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
case .verifyChallenge, .verifyResponse:
break
}
}
}
@@ -801,6 +801,19 @@ extension ChatViewModel {
messageRouter.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
}
private static func decodeEmbeddedBitChatPacket(from content: String) -> BitchatPacket? {
guard content.hasPrefix("bitchat1:") else { return nil }
let encoded = String(content.dropFirst("bitchat1:".count))
let maxBytes = FileTransferLimits.maxFramedFileBytes
// Base64url length upper bound for maxBytes (padded length; unpadded is <= this).
let maxEncoded = ((maxBytes + 2) / 3) * 4
guard encoded.count <= maxEncoded else { return nil }
guard let packetData = Self.base64URLDecode(encoded),
packetData.count <= maxBytes
else { return nil }
return BitchatPacket.from(packetData)
}
// MARK: - Geohash Nickname Resolution (for /block in geohash)
func nostrPubkeyForDisplayName(_ name: String) -> String? {