Encrypt private media before fragmentation

This commit is contained in:
jack
2026-07-10 21:00:54 +02:00
parent 733098bb63
commit 7faa9d7d4a
25 changed files with 893 additions and 138 deletions
@@ -33,6 +33,7 @@ struct BLEFileTransferHandlerTests {
recorder.signatureVerifyCount += 1
return recorder.signatureVerifies
},
localSigningPublicKey: { [sampleSigningKey] in sampleSigningKey },
signedSenderDisplayName: { _, peerID in
recorder.signedNameQueries.append(peerID)
return recorder.signedName
@@ -92,12 +93,11 @@ struct BLEFileTransferHandlerTests {
@Test
func selfEchoIsDropped() throws {
let recorder = Recorder()
recorder.signatureVerifies = true
let handler = makeHandler(recorder: recorder)
let packet = try makeFileTransferPacket(sender: localPeerID, mimeType: "application/pdf", content: Data("%PDF-1.7".utf8), ttl: 3)
// The relay pipeline already suppresses self-originated packets, so the
// handler reports "relayable" rather than treating the echo as forged.
#expect(handler.handle(packet, from: localPeerID))
#expect(!handler.handle(packet, from: localPeerID))
expectNoSideEffects(recorder)
}
@@ -120,7 +120,12 @@ struct BLEFileTransferHandlerTests {
let recorder = Recorder()
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Bob", isVerified: false, isConnected: true)]
let handler = makeHandler(recorder: recorder)
let packet = try makeFileTransferPacket(sender: remotePeerID, mimeType: "application/pdf", content: Data("%PDF-1.7".utf8))
let packet = try makeFileTransferPacket(
sender: remotePeerID,
mimeType: "application/pdf",
content: Data("%PDF-1.7".utf8),
hasSignature: false
)
// Failed sender authentication must also stop the packet from being
// relayed to downstream nodes.
@@ -129,7 +134,7 @@ struct BLEFileTransferHandlerTests {
// Broadcast files carry an attacker-controllable senderID, so like
// public messages a connected-but-unverified peer must present a valid
// packet signature. No signing key + no signed identity means dropped.
#expect(recorder.signedNameQueries == [remotePeerID])
#expect(recorder.signedNameQueries.isEmpty)
#expect(recorder.trackedPackets.isEmpty)
#expect(recorder.deliveredMessages.isEmpty)
}
@@ -153,12 +158,11 @@ struct BLEFileTransferHandlerTests {
}
@Test
func selfBroadcastReplayIsDeliveredWithoutSignatureCheck() throws {
// Our own broadcast file replayed via gossip sync arrives with ttl==0
// (so it is not treated as a self-echo) and cannot be verified against
// the peer registry it must still be accepted, matching
// BLEPublicMessageHandler's self exemption.
func signedSelfBroadcastReplayIsDelivered() throws {
// Our own broadcast file replayed via gossip sync arrives with ttl==0;
// it is verified against our local signing key before delivery.
let recorder = Recorder()
recorder.signatureVerifies = true
let handler = makeHandler(recorder: recorder)
let packet = try makeFileTransferPacket(
sender: localPeerID,
@@ -169,7 +173,7 @@ struct BLEFileTransferHandlerTests {
#expect(handler.handle(packet, from: localPeerID))
#expect(recorder.signatureVerifyCount == 0)
#expect(recorder.signatureVerifyCount == 1)
#expect(recorder.signedNameQueries.isEmpty)
#expect(recorder.deliveredMessages.count == 1)
#expect(recorder.deliveredMessages.first?.sender == "Me")
@@ -205,7 +209,8 @@ struct BLEFileTransferHandlerTests {
sender: remotePeerID,
mimeType: "audio/mp4",
content: m4a,
fileName: "voice_1122334455667788"
fileName: "voice_1122334455667788",
hasSignature: false
)
// The spoofed note must be dropped locally AND not relayed onward.
@@ -215,7 +220,7 @@ struct BLEFileTransferHandlerTests {
}
@Test
func privateFileFromConnectedUnverifiedPeerIsAccepted() throws {
func rawDirectedFileWithoutVerifiableSignatureIsDroppedWithoutWriteOrRelay() throws {
let recorder = Recorder()
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Bob", isVerified: false, isConnected: true)]
let handler = makeHandler(recorder: recorder)
@@ -223,23 +228,25 @@ struct BLEFileTransferHandlerTests {
sender: remotePeerID,
mimeType: "application/pdf",
content: Data("%PDF-1.7".utf8),
recipientID: Data(hexString: localPeerID.id)
recipientID: Data(hexString: localPeerID.id),
hasSignature: false
)
#expect(handler.handle(packet, from: remotePeerID))
#expect(!handler.handle(packet, from: remotePeerID))
// Directed transfers keep the lenient connected-peer path (no broadcast
// exposure); no signature check is required.
#expect(recorder.signatureVerifyCount == 0)
#expect(recorder.signedNameQueries.isEmpty)
#expect(recorder.deliveredMessages.count == 1)
#expect(recorder.deliveredMessages.first?.isPrivate == true)
#expect(recorder.trackedPackets.isEmpty)
#expect(recorder.quotaReservations.isEmpty)
#expect(recorder.saveCalls.isEmpty)
#expect(recorder.deliveredMessages.isEmpty)
}
@Test
func fileDirectedToAnotherPeerIsIgnored() throws {
let recorder = Recorder()
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true, signingPublicKey: sampleSigningKey)]
recorder.signatureVerifies = true
let handler = makeHandler(recorder: recorder)
let packet = try makeFileTransferPacket(
sender: remotePeerID,
@@ -260,7 +267,8 @@ struct BLEFileTransferHandlerTests {
@Test
func privateFileUpdatesLastSeenAndDeliversPrivateMessage() throws {
let recorder = Recorder()
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true, signingPublicKey: sampleSigningKey)]
recorder.signatureVerifies = true
let handler = makeHandler(recorder: recorder)
let packet = try makeFileTransferPacket(
sender: remotePeerID,
@@ -282,6 +290,56 @@ struct BLEFileTransferHandlerTests {
#expect(recorder.deliveredMessages.first?.deliveryStatus == .delivered(to: "Me", at: Date(timeIntervalSince1970: 900)))
}
@Test
func decryptedPrivateFileUsesValidationQuotaAndPrivateDeliveryWithoutRawSignature() throws {
let recorder = Recorder()
recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
let handler = makeHandler(recorder: recorder)
let content = Data([0xFF, 0xD8, 0xFF]) + Data(repeating: 0x41, count: 128)
let file = BitchatFilePacket(
fileName: "secret.jpg",
fileSize: UInt64(content.count),
mimeType: "image/jpeg",
content: content
)
let payload = try #require(file.encode())
let timestamp = Date(timeIntervalSince1970: 1_234)
#expect(handler.handlePrivatePayload(payload, from: remotePeerID, timestamp: timestamp))
#expect(recorder.signatureVerifyCount == 0)
#expect(recorder.signedNameQueries.isEmpty)
#expect(recorder.trackedPackets.isEmpty)
#expect(recorder.quotaReservations == [content.count])
#expect(recorder.saveCalls.first?.data == content)
#expect(recorder.lastSeenUpdates == [remotePeerID])
#expect(recorder.deliveredMessages.count == 1)
#expect(recorder.deliveredMessages.first?.isPrivate == true)
#expect(recorder.deliveredMessages.first?.timestamp == timestamp)
}
@Test
func decryptedPrivateFileOverPayloadCapIsRejectedBeforeQuotaOrDiskWrite() {
let recorder = Recorder()
let handler = makeHandler(recorder: recorder)
let oversizedCount = FileTransferLimits.maxPayloadBytes + 1
var length = UInt32(oversizedCount).bigEndian
var payload = Data([0x04]) // BitchatFilePacket CONTENT TLV
withUnsafeBytes(of: &length) { payload.append(contentsOf: $0) }
payload.append(Data(repeating: 0x41, count: oversizedCount))
#expect(!handler.handlePrivatePayload(
payload,
from: remotePeerID,
timestamp: Date(timeIntervalSince1970: 1_234)
))
#expect(recorder.quotaReservations.isEmpty)
#expect(recorder.saveCalls.isEmpty)
#expect(recorder.lastSeenUpdates.isEmpty)
#expect(recorder.deliveredMessages.isEmpty)
}
@Test
func malformedPayloadIsTrackedForSyncButDropped() {
let recorder = Recorder()
@@ -294,7 +352,7 @@ struct BLEFileTransferHandlerTests {
recipientID: nil,
timestamp: 900_000,
payload: Data([0x01, 0x02, 0x03]),
signature: nil,
signature: Data(repeating: 0x5A, count: 64),
ttl: TransportConfig.messageTTLDefault
)
@@ -403,7 +461,8 @@ struct BLEFileTransferHandlerTests {
content: Data,
ttl: UInt8 = TransportConfig.messageTTLDefault,
recipientID: Data? = nil,
fileName: String = "sample"
fileName: String = "sample",
hasSignature: Bool = true
) throws -> BitchatPacket {
let filePacket = BitchatFilePacket(
fileName: fileName,
@@ -418,7 +477,7 @@ struct BLEFileTransferHandlerTests {
recipientID: recipientID,
timestamp: 900_000,
payload: payload,
signature: nil,
signature: hasSignature ? Data(repeating: 0x5A, count: 64) : nil,
ttl: ttl
)
}
@@ -117,6 +117,35 @@ struct BLEFragmentAssemblyBufferTests {
}
}
@Test
func encryptedPrivateFileAssemblyGetsFramedFileHeadroom() throws {
var buffer = BLEFragmentAssemblyBuffer()
let fragmentID = Data(repeating: 0x15, count: 8)
let first = try #require(BLEFragmentHeader(packet: makeFragmentPacket(
fragmentID: fragmentID,
index: 0,
total: 2,
originalType: MessageType.noiseEncrypted.rawValue,
fragmentData: Data(repeating: 0x01, count: FileTransferLimits.maxPayloadBytes)
)))
let second = try #require(BLEFragmentHeader(packet: makeFragmentPacket(
fragmentID: fragmentID,
index: 1,
total: 2,
originalType: MessageType.noiseEncrypted.rawValue,
fragmentData: Data([0x02])
)))
_ = buffer.append(first, maxInFlightAssemblies: 8)
let result = buffer.append(second, maxInFlightAssemblies: 8)
if case let .complete(_, data, _) = result {
#expect(data.count == FileTransferLimits.maxPayloadBytes + 1)
} else {
Issue.record("Expected encrypted private-file assembly to use framed-file limit")
}
}
@Test
func removeExpiredDropsOldAssemblies() throws {
var buffer = BLEFragmentAssemblyBuffer()
@@ -31,4 +31,23 @@ struct BLENoisePayloadFactoryTests {
#expect(payload == Data([NoisePayloadType.verifyChallenge.rawValue, 0xCA, 0xFE]))
}
@Test
func privateFilePayloadPrefixesCanonicalFilePacket() throws {
let content = Data("%PDF-secret".utf8)
let file = BitchatFilePacket(
fileName: "secret.pdf",
fileSize: UInt64(content.count),
mimeType: "application/pdf",
content: content
)
let payload = try #require(BLENoisePayloadFactory.privateFile(file))
#expect(payload.first == NoisePayloadType.privateFile.rawValue)
let decoded = try #require(BitchatFilePacket.decode(Data(payload.dropFirst())))
#expect(decoded.fileName == "secret.pdf")
#expect(decoded.mimeType == "application/pdf")
#expect(decoded.content == content)
}
}
@@ -48,7 +48,10 @@ struct BLENoiseSessionQueuesTests {
queues.appendTypedPayload(Data([0x01]), for: peerID)
queues.appendTypedPayload(Data([0x02]), for: peerID)
#expect(queues.takeTypedPayloads(for: peerID) == [Data([0x01]), Data([0x02])])
#expect(queues.takeTypedPayloads(for: peerID) == [
BLEPendingTypedPayload(payload: Data([0x01]), transferId: nil),
BLEPendingTypedPayload(payload: Data([0x02]), transferId: nil)
])
#expect(queues.takeTypedPayloads(for: peerID).isEmpty)
#expect(queues.takePrivateMessages(for: peerID).map(\.messageID) == ["m1"])
}
@@ -64,4 +67,21 @@ struct BLENoiseSessionQueuesTests {
#expect(queues.isEmpty)
}
@Test
func transferIDSurvivesHandshakeQueueAndCanBeCancelledBeforeDrain() {
let peerID = PeerID(str: "aaaaaaaaaaaaaaaa")
var queues = BLENoiseSessionQueues()
queues.appendTypedPayload(Data([0x09, 0xAA]), transferId: "media-1", for: peerID)
queues.appendTypedPayload(Data([0x01, 0xBB]), for: peerID)
let removed = queues.removeTypedPayload(transferId: "media-1")
let removedAgain = queues.removeTypedPayload(transferId: "media-1")
#expect(removed)
#expect(!removedAgain)
#expect(queues.takeTypedPayloads(for: peerID) == [
BLEPendingTypedPayload(payload: Data([0x01, 0xBB]), transferId: nil)
])
}
}
@@ -20,6 +20,24 @@ struct BLEOutboundFragmentTransferSchedulerTests {
}
}
@Test
func explicitTransferIDReservesEncryptedPrivateFileFragments() {
var scheduler = BLEOutboundFragmentTransferScheduler()
let request = makeRequest(
type: MessageType.noiseEncrypted.rawValue,
transferId: "private-media"
)
let result = scheduler.submit(request, maxConcurrentTransfers: 1)
if case let .start(_, reservedTransferId) = result {
#expect(reservedTransferId == "private-media")
#expect(scheduler.activeCount == 1)
} else {
Issue.record("Expected encrypted private media to reserve its progress slot")
}
}
@Test
func submitQueuesFileTransferWhenSlotsAreFull() {
var scheduler = BLEOutboundFragmentTransferScheduler()
@@ -126,6 +126,55 @@ struct NoiseEncryptionServiceTests {
#expect(bob.getPeerFingerprint(bobPeerID) == nil)
}
@Test("Large private-file payloads use the bounded Noise extension")
func largePrivateFileNoiseRoundTrip() throws {
let alice = NoiseEncryptionService(keychain: MockKeychain())
let bob = NoiseEncryptionService(keychain: MockKeychain())
let alicePeerID = PeerID(str: "0011223344556677")
let bobPeerID = PeerID(str: "8899aabbccddeeff")
try establishSessions(alice: alice, bob: bob, alicePeerID: alicePeerID, bobPeerID: bobPeerID)
let content = Data("%PDF-1.7\n".utf8) + Data(repeating: 0x51, count: 96 * 1024)
let file = BitchatFilePacket(
fileName: "large-private.pdf",
fileSize: UInt64(content.count),
mimeType: "application/pdf",
content: content
)
let typedPayload = try #require(BLENoisePayloadFactory.privateFile(file))
#expect(typedPayload.count > NoiseSecurityConstants.maxMessageSize)
#expect(typedPayload.first == NoisePayloadType.privateFile.rawValue)
#expect(
typedPayload.count <= NoiseSecurityConstants.maxPrivateFilePlaintextSize,
"typedBytes=\(typedPayload.count) limit=\(NoiseSecurityConstants.maxPrivateFilePlaintextSize)"
)
do {
_ = try alice.encrypt(typedPayload, for: alicePeerID)
Issue.record("Ordinary Noise payload path must retain its 64 KiB ceiling")
} catch NoiseSecurityError.messageTooLarge {
// Expected: only the purpose-specific private-file API may extend it.
}
let ciphertext: Data
do {
ciphertext = try alice.encryptPrivateFilePayload(typedPayload, for: alicePeerID)
} catch {
Issue.record("Private-file encryption failed: \(error)")
return
}
let decrypted: Data
do {
decrypted = try bob.decrypt(ciphertext, from: bobPeerID)
} catch {
Issue.record("Private-file decryption failed: \(error); ciphertextBytes=\(ciphertext.count)")
return
}
#expect(ciphertext.range(of: content) == nil)
#expect(decrypted == typedPayload)
}
@Test("Encrypt without a session requests handshake and decrypt without session fails")
func handshakeRequiredAndSessionNotEstablishedErrors() throws {
let service = NoiseEncryptionService(keychain: MockKeychain())
@@ -105,6 +105,30 @@ struct TransferProgressManagerTests {
#expect(manager.snapshot(id: transferID) == nil)
_ = cancellable
}
@Test("Preflight rejection publishes cancellation without a started state")
@MainActor
func rejectBeforeStartPublishesCancellation() async {
let manager = TransferProgressManager()
let transferID = "transfer-preflight-reject"
var cancellable: AnyCancellable?
let recorder = EventRecorder()
cancellable = manager.publisher.sink { event in
if case .cancelled(let id, let sent, let total) = event {
recorder.append("cancelled:\(id):\(sent):\(total)")
}
}
manager.rejectBeforeStart(id: transferID)
let didReceive = await TestHelpers.waitUntil({
recorder.values == ["cancelled:\(transferID):0:0"]
}, timeout: 5.0)
#expect(didReceive)
#expect(manager.snapshot(id: transferID) == nil)
_ = cancellable
}
}
private final class EventRecorder: @unchecked Sendable {