Version fetching API added

app/src/main/java/org/thoughtcrime/securesms/util/VersionUtil.kt

@@ -0,0 +1,44 @@
+package org.thoughtcrime.securesms.util
+
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import org.session.libsession.utilities.TextSecurePreferences
+
+class VersionUtil(
+    private val context: Context,
+    private val prefs: TextSecurePreferences
+) {
+
+    private val handler = Handler(Looper.getMainLooper())
+    private val runnable: Runnable
+
+    init {
+        runnable = Runnable {
+            // Task to be executed every 4 hours
+            fetchVersionData()
+        }
+
+        // Re-schedule the task
+        handler.postDelayed(runnable, FOUR_HOURS)
+    }
+
+    fun startTimedVersionCheck() {
+        handler.post(runnable)
+    }
+
+    fun stopTimedVersionCheck() {
+        handler.removeCallbacks(runnable)
+    }
+
+    private fun fetchVersionData() {
+        // only perform this if at least 4h has elapsed since th last successful check
+        if(prefs.getLastVersionCheck() < FOUR_HOURS) return
+
+
+    }
+
+    companion object {
+        private const val FOUR_HOURS = 4 * 60 * 60 * 1000L // 4 hours in milliseconds
+    }
+}

libsession/src/main/java/org/session/libsession/messaging/file_server/FileServerApi.kt

@@ -1,18 +1,22 @@
 package org.session.libsession.messaging.file_server
 
+import android.util.Base64
+import network.loki.messenger.libsession_util.util.BlindKeyAPI
 import nl.komponents.kovenant.Promise
 import nl.komponents.kovenant.functional.map
-import okhttp3.Headers
 import okhttp3.Headers.Companion.toHeaders
 import okhttp3.HttpUrl
 import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
-import okhttp3.MediaType
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.RequestBody
+import org.session.libsession.messaging.MessagingModuleConfiguration
 import org.session.libsession.snode.OnionRequestAPI
+import org.session.libsession.snode.utilities.await
 import org.session.libsignal.utilities.HTTP
 import org.session.libsignal.utilities.JsonUtil
 import org.session.libsignal.utilities.Log
+import org.session.libsignal.utilities.toHexString
+import java.util.concurrent.TimeUnit
 
 object FileServerApi {
 
@@ -23,6 +27,7 @@ object FileServerApi {
     sealed class Error(message: String) : Exception(message) {
         object ParsingFailed : Error("Invalid response.")
         object InvalidURL : Error("Invalid URL.")
+        object NoEd25519KeyPair : Error("Couldn't find ed25519 key pair.")
     }
 
     data class Request(
@@ -105,4 +110,52 @@ object FileServerApi {
         val request = Request(verb = HTTP.Verb.GET, endpoint = "file/$file")
         return send(request)
     }
+
+    /**
+     * Returns the current version of session
+     * This is effectively proxying (and caching) the response from the github release
+     * page.
+     *
+     * Note that the value is cached and can be up to 30 minutes out of date normally, and up to 24
+     * hours out of date if we cannot reach the Github API for some reason.
+     *
+     * https://github.com/oxen-io/session-file-server/blob/dev/doc/api.yaml#L119
+     */
+    suspend fun getClientVersion(): VersionData {
+        // Generate the auth signature
+        val secretKey =  MessagingModuleConfiguration.shared.getUserED25519KeyPair()?.secretKey?.asBytes
+            ?: throw (Error.NoEd25519KeyPair)
+
+        val blindedKeys = BlindKeyAPI.blindVersionKeyPair(secretKey)
+        val timestamp = TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis()) //  The current timestamp in seconds
+        val signature = BlindKeyAPI.blindVersionSign(secretKey, timestamp)
+
+        // The hex encoded version-blinded public key with a 07 prefix
+        val blindedPkHex = buildString {
+            append("07")
+            append(blindedKeys.pubKey.toHexString())
+        }
+
+        val request = Request(
+            verb = HTTP.Verb.GET,
+            endpoint = "session_version",
+            queryParameters = mapOf("platform" to "android"),
+            headers = mapOf(
+                "X-FS-Pubkey" to blindedPkHex,
+                "X-FS-Timestamp" to timestamp.toString(),
+                "X-FS-Signature" to Base64.encodeToString(signature, Base64.NO_WRAP)
+            )
+        )
+
+        // transform the promise into a coroutine
+        val result = send(request).await()
+
+        // map out the result
+        val json = JsonUtil.fromJson(result, Map::class.java)
+        val statusCode = json.getOrDefault("status_code", 0) as Int
+        val version = json.getOrDefault("result", "") as String
+        val updated = json.getOrDefault("updated", 0.0) as Double
+
+        return VersionData(statusCode, version, updated)
+    }
 }

libsession/src/main/java/org/session/libsession/messaging/file_server/VersionData.kt

@@ -0,0 +1,7 @@
+package org.session.libsession.messaging.file_server
+
+data class VersionData(
+    val statusCode: Int, // The value 200. Included for backwards compatibility, and may be removed someday.
+    val version: String, // The Session version.
+    val updated: Double // The unix timestamp when this version was retrieved from Github; this can be up to 24 hours ago in case of consistent fetch errors, though normally will be within the last 30 minutes.
+)

libsession/src/main/java/org/session/libsession/snode/utilities/PromiseUtil.kt

@@ -0,0 +1,13 @@
+package org.session.libsession.snode.utilities
+
+import nl.komponents.kovenant.Promise
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
+import kotlin.coroutines.suspendCoroutine
+
+suspend fun <T, E: Throwable> Promise<T, E>.await(): T {
+    return suspendCoroutine { cont ->
+        success { cont.resume(it) }
+        fail { cont.resumeWithException(it) }
+    }
+}

libsession/src/main/java/org/session/libsession/utilities/TextSecurePreferences.kt

@@ -13,6 +13,7 @@ import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import org.session.libsession.R
+import org.session.libsession.utilities.TextSecurePreferences.Companion
 import org.session.libsession.utilities.TextSecurePreferences.Companion.AUTOPLAY_AUDIO_MESSAGES
 import org.session.libsession.utilities.TextSecurePreferences.Companion.CALL_NOTIFICATIONS_ENABLED
 import org.session.libsession.utilities.TextSecurePreferences.Companion.CLASSIC_DARK
@@ -20,6 +21,7 @@ import org.session.libsession.utilities.TextSecurePreferences.Companion.CLASSIC_
 import org.session.libsession.utilities.TextSecurePreferences.Companion.FOLLOW_SYSTEM_SETTINGS
 import org.session.libsession.utilities.TextSecurePreferences.Companion.HIDE_PASSWORD
 import org.session.libsession.utilities.TextSecurePreferences.Companion.LAST_VACUUM_TIME
+import org.session.libsession.utilities.TextSecurePreferences.Companion.LAST_VERSION_CHECK
 import org.session.libsession.utilities.TextSecurePreferences.Companion.LEGACY_PREF_KEY_SELECTED_UI_MODE
 import org.session.libsession.utilities.TextSecurePreferences.Companion.OCEAN_DARK
 import org.session.libsession.utilities.TextSecurePreferences.Companion.OCEAN_LIGHT
@@ -186,6 +188,8 @@ interface TextSecurePreferences {
     fun clearAll()
     fun getHidePassword(): Boolean
     fun setHidePassword(value: Boolean)
+    fun getLastVersionCheck(): Long
+    fun setLastVersionCheck()
 
     companion object {
         val TAG = TextSecurePreferences::class.simpleName
@@ -272,6 +276,7 @@ interface TextSecurePreferences {
         const val AUTOPLAY_AUDIO_MESSAGES = "pref_autoplay_audio"
         const val FINGERPRINT_KEY_GENERATED = "fingerprint_key_generated"
         const val SELECTED_ACCENT_COLOR = "selected_accent_color"
+        const val LAST_VERSION_CHECK = "pref_last_version_check"
 
         const val HAS_RECEIVED_LEGACY_CONFIG = "has_received_legacy_config"
         const val HAS_FORCED_NEW_CONFIG = "has_forced_new_config"
@@ -1541,6 +1546,14 @@ class AppTextSecurePreferences @Inject constructor(
         setLongPreference(LAST_VACUUM_TIME, System.currentTimeMillis())
     }
 
+    override fun getLastVersionCheck(): Long {
+        return getLongPreference(LAST_VERSION_CHECK, 0)
+    }
+
+    override fun setLastVersionCheck() {
+        setLongPreference(LAST_VERSION_CHECK, System.currentTimeMillis())
+    }
+
     override fun setShownCallNotification(): Boolean {
         val previousValue = getBooleanPreference(SHOWN_CALL_NOTIFICATION, false)
         if (previousValue) return false