Install event firmware in-app behind a signed release contract

Localizable.xcstrings

@@ -113610,7 +113610,49 @@
     "Your radio is rebooting to save the imported settings — reconnect to verify.": {},
     "channel keys (PSKs)": {},
     "sensitive credentials": {},
-    "your node's private key & admin keys": {}
+    "your node's private key & admin keys": {},
+    "In-app installation requires bootloader %@ or newer.": {
+      "comment": "Event firmware installer requirement. The argument is the minimum bootloader version."
+    },
+    "In-app installation requires device firmware %@ or newer.": {
+      "comment": "Event firmware installer requirement. The argument is the minimum source firmware version."
+    },
+    "Install Event Firmware": {
+      "comment": "Primary action for installing an event firmware edition."
+    },
+    "No package is published for this exact device target.": {
+      "comment": "Event firmware installer unavailable reason."
+    },
+    "No trusted installation contract is currently published for this event.": {
+      "comment": "Event firmware installer unavailable reason."
+    },
+    "Reconnect to this device before preparing its firmware package.": {
+      "comment": "Event firmware installer error shown when its target device is disconnected."
+    },
+    "Return to Standard Firmware": {
+      "comment": "Primary action for replacing an event firmware edition with standard firmware."
+    },
+    "The available package does not meet the app's download trust policy.": {
+      "comment": "Event firmware installer unavailable reason."
+    },
+    "The connected device changed. Select the event again for the current device.": {
+      "comment": "Event firmware installer error shown when the connected target changes during preparation."
+    },
+    "The download is verified before the existing firmware installer is opened. Keep the app open and your device nearby during installation.": {
+      "comment": "Footer explaining the verified event firmware installation flow."
+    },
+    "The firmware package could not be downloaded and verified.": {
+      "comment": "Generic event firmware package preparation error."
+    },
+    "The published installation contract is for a different event.": {
+      "comment": "Event firmware installer unavailable reason."
+    },
+    "This app cannot verify a compatible in-app package for this exact device. The web flasher provides the supported installation path.": {
+      "comment": "Footer explaining why the event firmware installer falls back to the web flasher."
+    },
+    "This device does not have an app-supported event firmware OTA path.": {
+      "comment": "Event firmware installer unavailable reason."
+    }
   },
   "version": "1.1"
-}
+}

Meshtastic/API/MeshtasticAPI.swift

@@ -1070,21 +1070,21 @@ extension MeshtasticAPI {
 					context.insert(entity)
 				}
 
-				if let value = payload.displayName { entity.displayName = value }
-				if let value = payload.welcomeMessage { entity.welcomeMessage = value }
-				if let value = payload.tag { entity.tag = value }
-				if let value = payload.eventStart { entity.eventStart = value }
-				if let value = payload.eventEnd { entity.eventEnd = value }
-				if let value = payload.timeZone { entity.timeZone = value }
-				if let value = payload.location { entity.location = value }
+				if let value = payload.displayName, !value.isEmpty { entity.displayName = value }
+				if let value = payload.welcomeMessage, !value.isEmpty { entity.welcomeMessage = value }
+				if let value = payload.tag, !value.isEmpty { entity.tag = value }
+				if let value = payload.eventStart, !value.isEmpty { entity.eventStart = value }
+				if let value = payload.eventEnd, !value.isEmpty { entity.eventEnd = value }
+				if let value = payload.timeZone, !value.isEmpty { entity.timeZone = value }
+				if let value = payload.location, !value.isEmpty { entity.location = value }
 				if let value = EventFirmwareURLPolicy.httpsURL(from: payload.iconUrl)?.absoluteString {
 					entity.iconUrl = value
 				}
 				if let value = payload.accentColor,
 				   EventFirmwareEntity.color(fromHex: value) != nil {
 					entity.accentColor = value
 				}
-				if let value = payload.domain { entity.domain = value }
+				if let value = payload.domain, !value.isEmpty { entity.domain = value }
 				if let links = payload.links {
 					let safeLinks = links.map {
 						EventFirmwareEntity.Link(label: $0.label, url: $0.url)
@@ -1095,8 +1095,8 @@ extension MeshtasticAPI {
 						entity.setLinks(safeLinks)
 					}
 				}
-				if let value = payload.theme?.name { entity.themeName = value }
-				if let value = payload.theme?.tagline { entity.themeTagline = value }
+				if let value = payload.theme?.name, !value.isEmpty { entity.themeName = value }
+				if let value = payload.theme?.tagline, !value.isEmpty { entity.themeTagline = value }
 				if let value = payload.theme?.colors?.primary,
 				   EventFirmwareEntity.color(fromHex: value) != nil {
 					entity.themePrimaryColor = value
@@ -1117,13 +1117,15 @@ extension MeshtasticAPI {
 						entity.themePalette = validPalette
 					}
 				}
-				if let value = payload.theme?.fonts?.heading { entity.themeFontHeading = value }
-				if let value = payload.theme?.fonts?.body { entity.themeFontBody = value }
-				if let value = payload.firmware?.slug { entity.firmwareSlug = value }
-				if let value = payload.firmware?.version { entity.firmwareVersion = value }
-				if let value = payload.firmware?.id { entity.firmwareId = value }
-				if let value = payload.firmware?.title { entity.firmwareTitle = value }
-				if let value = payload.firmware?.releaseNotes { entity.firmwareReleaseNotes = value }
+				if let value = payload.theme?.fonts?.heading, !value.isEmpty { entity.themeFontHeading = value }
+				if let value = payload.theme?.fonts?.body, !value.isEmpty { entity.themeFontBody = value }
+				if let value = payload.firmware?.slug, !value.isEmpty { entity.firmwareSlug = value }
+				if let value = payload.firmware?.version, !value.isEmpty { entity.firmwareVersion = value }
+				if let value = payload.firmware?.id, !value.isEmpty { entity.firmwareId = value }
+				if let value = payload.firmware?.title, !value.isEmpty { entity.firmwareTitle = value }
+				if let value = payload.firmware?.releaseNotes, !value.isEmpty {
+					entity.firmwareReleaseNotes = value
+				}
 			}
 
 			try? context.save()

Meshtastic/Assets.xcassets/EventFirmwareHAMVENTION.imageset/Contents.json

@@ -2,8 +2,7 @@
   "images" : [
     {
       "filename" : "hamvention.png",
-      "idiom" : "universal",
-      "scale" : "1x"
+      "idiom" : "universal"
     }
   ],
   "info" : {

Meshtastic/Model/EventFirmwareArtifactDownloader.swift

@@ -0,0 +1,172 @@
+// MARK: EventFirmwareArtifactDownloader.swift
+
+import CryptoKit
+import Foundation
+
+enum EventFirmwareArtifactDownloadError: Error, Equatable {
+	case unexpectedResponseURL
+	case httpStatus(Int)
+	case byteCountMismatch
+	case checksumMismatch
+}
+
+actor EventFirmwareArtifactDownloader {
+	typealias Download = @Sendable (URL, Int64) async throws -> (URL, URLResponse)
+
+	private let cacheDirectory: URL
+	private let download: Download
+
+	init(
+		cacheDirectory: URL = FileManager.default.urls(
+			for: .cachesDirectory,
+			in: .userDomainMask
+		)[0].appendingPathComponent("EventFirmware", isDirectory: true),
+		session: URLSession = .shared
+	) {
+		self.cacheDirectory = cacheDirectory
+		download = { url, maximumByteCount in
+			let delegate = EventFirmwareBoundedDownloadDelegate(
+				maximumByteCount: maximumByteCount
+			)
+			do {
+				return try await session.download(
+					for: URLRequest(url: url),
+					delegate: delegate
+				)
+			} catch {
+				if delegate.exceededMaximumByteCount {
+					throw EventFirmwareArtifactDownloadError.byteCountMismatch
+				}
+				throw error
+			}
+		}
+	}
+
+	init(
+		cacheDirectory: URL,
+		download: @escaping Download
+	) {
+		self.cacheDirectory = cacheDirectory
+		self.download = download
+	}
+
+	func prepare(_ artifact: EventFirmwareOTAArtifact) async throws -> URL {
+		try Task.checkCancellation()
+		try FileManager.default.createDirectory(
+			at: cacheDirectory,
+			withIntermediateDirectories: true
+		)
+
+		let destination = cacheDirectory.appendingPathComponent(
+			artifact.sha256.lowercased()
+		).appendingPathExtension(artifact.format.fileExtension)
+		if FileManager.default.fileExists(atPath: destination.path) {
+			if (try? verify(file: destination, against: artifact)) == true {
+				return destination
+			}
+			try FileManager.default.removeItem(at: destination)
+		}
+
+		let (downloadedURL, response) = try await download(
+			artifact.url,
+			artifact.byteCount
+		)
+		try Task.checkCancellation()
+		guard response.url == artifact.url else {
+			throw EventFirmwareArtifactDownloadError.unexpectedResponseURL
+		}
+		if let httpResponse = response as? HTTPURLResponse,
+		   !(200...299).contains(httpResponse.statusCode) {
+			throw EventFirmwareArtifactDownloadError.httpStatus(httpResponse.statusCode)
+		}
+
+		let stagingURL = cacheDirectory.appendingPathComponent(
+			".\(UUID().uuidString).partial"
+		)
+		defer {
+			try? FileManager.default.removeItem(at: stagingURL)
+		}
+		try FileManager.default.moveItem(at: downloadedURL, to: stagingURL)
+		guard try verify(file: stagingURL, against: artifact) else {
+			throw EventFirmwareArtifactDownloadError.checksumMismatch
+		}
+		try FileManager.default.moveItem(at: stagingURL, to: destination)
+		return destination
+	}
+
+	private func verify(
+		file: URL,
+		against artifact: EventFirmwareOTAArtifact
+	) throws -> Bool {
+		let verification = try digestAndSize(of: file)
+		guard verification.byteCount == artifact.byteCount else {
+			throw EventFirmwareArtifactDownloadError.byteCountMismatch
+		}
+		return verification.sha256.caseInsensitiveCompare(artifact.sha256) == .orderedSame
+	}
+
+	private func digestAndSize(of file: URL) throws -> (sha256: String, byteCount: Int64) {
+		let handle = try FileHandle(forReadingFrom: file)
+		defer {
+			try? handle.close()
+		}
+		var hasher = SHA256()
+		var byteCount: Int64 = 0
+		while let chunk = try handle.read(upToCount: 64 * 1_024), !chunk.isEmpty {
+			try Task.checkCancellation()
+			byteCount += Int64(chunk.count)
+			hasher.update(data: chunk)
+		}
+		let sha256 = hasher.finalize().map { String(format: "%02x", $0) }.joined()
+		return (sha256, byteCount)
+	}
+}
+
+/// Cancels a URL session download task as soon as its streamed byte count exceeds a trusted limit.
+final class EventFirmwareBoundedDownloadDelegate: NSObject,
+	URLSessionDownloadDelegate,
+	@unchecked Sendable {
+
+	private let maximumByteCount: Int64
+	private let lock = NSLock()
+	private var exceeded = false
+
+	var exceededMaximumByteCount: Bool {
+		lock.withLock { exceeded }
+	}
+
+	init(maximumByteCount: Int64) {
+		self.maximumByteCount = maximumByteCount
+	}
+
+	func urlSession(
+		_ session: URLSession,
+		downloadTask: URLSessionDownloadTask,
+		didFinishDownloadingTo location: URL
+	) {}
+
+	func urlSession(
+		_ session: URLSession,
+		downloadTask: URLSessionDownloadTask,
+		didWriteData bytesWritten: Int64,
+		totalBytesWritten: Int64,
+		totalBytesExpectedToWrite: Int64
+	) {
+		guard totalBytesWritten > maximumByteCount else { return }
+		lock.withLock {
+			exceeded = true
+		}
+		downloadTask.cancel()
+	}
+}
+
+private extension EventFirmwareOTAArtifact.Format {
+	var fileExtension: String {
+		switch self {
+		case .bin:
+			return "bin"
+		case .otaZip:
+			return "zip"
+		}
+	}
+}