partially enable restart feature for epic users

requires legendary/heroic

CHANGELOG.md

@@ -11,6 +11,11 @@
     "restartOnRelaunch": true  
   }]
   ```
+
+### Enhancements
+- Enable restart feature for Epic users. It's still not as seamless as non-Epic accounts. Requires the usage of [Legendary]
+  or [Heroic]. Once you've logged in with either, you can go back to using the normal Epic launcher if you wish. It will
+  require re-logging in every few days though, so it may be preferable to just stick with the alternate launchers.
 
 ## [0.10.1] - 2024-05-03
 
@@ -339,4 +344,5 @@ Initial release
 [CVE-2023-36796]: https://github.com/dotnet/announcements/issues/274
 [CVE-2023-36799]: https://github.com/dotnet/announcements/issues/275
 [legendary]: https://github.com/derrod/legendary
+[heroic]: https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher
 [settings file]: README.md#settings

README.md

@@ -55,8 +55,8 @@ accounts on both Windows and Linux.
 * **Auto-restart**
 
   Automatically restart your game. This can be useful if you're [grinding] for manufactured 
-  engineering materials. Off by default. This feature isn't supported on the Epic platform.
-  See the [Min-Launcher-Specific] section for more details.
+  engineering materials. Off by default. For the Epic platform, this feature requires either 
+  [Legendary] or [Heroic]. See the [Epic accounts and the /restart feature] section for more details.
 
 * **Multi-Account**
 
@@ -170,9 +170,17 @@ The following arguments are in addition to the above:
 | /restart delay         | Restart the game after it has closed with _delay_ being the number of seconds given to cancel the restart (i.e `/restart 3`)                                                                            |
 | /dryrun                | Prints output without launching any processes                                                                                                                                                           |
 
-Note that the restart feature doesn't work with Epic accounts. After Elite launches, it invalidates
-the launcher's auth token and doesn't communicate the new token which then prevents the ability to
-login with FDev servers a second time.
+##### Epic accounts and the /restart feature
+The restart feature requires either [Legendary] or [Heroic] to work with Epic accounts.
+
+After Elite launches, it invalidates the launcher's initial Epic auth token and doesn't communicate
+the new token which then prevents the ability to login with FDev servers a second time. To work around
+this, min-ed-launcher can use a more privileged Epic token (created by Legendary/Heroic) to generate
+the needed auth tokens. Simply logging in with Legendary or Heroic will allow min-ed-launcher to restart
+without re-launching.
+
+Once you've logged in with either, you can go back to using the normal Epic launcher if you wish. It 
+will require re-logging in every few days though, so it may be preferable to just stick with the alternate launchers.
 
 ### Settings
 The settings file controls additional settings for the launcher that go beyond what the default
@@ -369,6 +377,7 @@ Note that the bootstrap project specifically targets Windows and won't publish o
 [Arguments]: #arguments
 [Shared]: #shared
 [Min-Launcher-Specific]: #min-launcher-specific
+[Epic accounts and the /restart feature]: #epic-accounts-and-the-restart-feature
 [Multi-Account]: #multi-account
 [Frontier account via Steam or Epic]: #frontier-account-via-steam-or-epic
 [Epic account via Steam]: #epic-account-via-steam
@@ -377,6 +386,7 @@ Note that the bootstrap project specifically targets Windows and won't publish o
 [Build]: #build
 [Release Artifacts]: #release-artifacts
 [legendary]: https://github.com/derrod/legendary
+[heroic]: https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher
 [quirks]: https://github.com/rfvgyhn/min-ed-launcher/issues/45#issuecomment-1030312606
 [publish.sh]: publish.sh
 [publish.ps1]: publish.ps1

src/MinEdLauncher/App.fs

@@ -62,10 +62,11 @@ let login launcherVersion runningTime httpClient machineId (platform: Platform)
         let! result = steam.Login() |> Result.map (fun steamUser -> Permanent steamUser.SessionToken) |> (authenticate None)
         return result }
     | Epic details -> task {
-        match! Epic.login launcherVersion details with
+        match! Epic.loginWithCode launcherVersion details.ExchangeCode with
         | Ok t ->
-            let tokenManager = new RefreshableTokenManager(t, Epic.refreshToken launcherVersion)
-            let! result = tokenManager.Get |> Expires |> Ok |> (authenticate (Some tokenManager)) 
+            let loginViaLegendary() = Legendary.getAccessToken() |> Result.bindTask (Epic.loginWithExistingToken launcherVersion)
+            let tokenManager = new RefreshableTokenManager(t, Epic.refreshToken launcherVersion, loginViaLegendary)
+            let! result = {| Get = tokenManager.Get; Renew = tokenManager.Renew |} |> Expires |> Ok |> (authenticate (Some tokenManager)) 
             return result
         | Error msg -> return Failure msg |> Error }
 
@@ -242,6 +243,7 @@ type AppError =
     | Login of LoginError
     | NoSelectedProduct
     | InvalidProductState of string
+    | InvalidSession of string
 
 [<RequireQualifiedAccess>]
 module AppError =
@@ -269,6 +271,7 @@ module AppError =
             $"Frontier was unable to verify that you own the game. This happens intermittently. Possible fixes include:{Environment.NewLine}{possibleFixes}"
         | NoSelectedProduct -> "No selected project"
         | InvalidProductState m -> $"Couldn't start selected product: %s{m}"
+        | InvalidSession m -> $"Invalid session: %s{m}"
 
 let private createGetRunningTime httpClient = task {
     let localTime = DateTime.UtcNow
@@ -285,7 +288,13 @@ let private createGetRunningTime httpClient = task {
         (double remoteTime + runningTime.TotalSeconds)
 }
 
-let rec private launchLoop initialLaunch settings playableProducts persistentRunning relaunchRunning cancellationToken processArgs = taskResult {      
+let private renewEpicTokenIfNeeded platform token =
+    match platform, token with
+    | Epic _, Expires t -> t.Renew()
+    | _ -> Ok () |> Task.fromResult
+    |> TaskResult.mapError InvalidSession
+
+let rec private launchLoop initialLaunch settings playableProducts (session: EdSession) persistentRunning relaunchRunning cancellationToken processArgs = taskResult {      
     let! selectedProduct = 
         if settings.AutoRun && initialLaunch then
             playableProducts
@@ -318,6 +327,8 @@ let rec private launchLoop initialLaunch settings playableProducts persistentRun
                 else
                     settings.Processes |> List.filter (fun p -> not p.RestartOnRelaunch) |> List.map _.Info, relaunchProcesses
 
+        if not initialLaunch then
+            do! renewEpicTokenIfNeeded settings.Platform session.PlatformToken
 
         let persistentProcesses = persistentRunning |> Option.defaultWith (fun () -> Process.launchProcesses persistentStartInfos)
         let mutable relaunchProcesses = Process.launchProcesses relaunchStartInfos
@@ -333,14 +344,13 @@ let rec private launchLoop initialLaunch settings playableProducts persistentRun
             Process.stopProcesses settings.ShutdownTimeout relaunchProcesses
             logStart relaunchStartInfos
             relaunchProcesses <- Process.launchProcesses relaunchStartInfos
+
+            do! renewEpicTokenIfNeeded settings.Platform session.PlatformToken
+
             launchProduct settings.DryRun settings.CompatTool pArgs selectedProduct.Name p
 
         if not settings.AutoQuit then
-            match settings.Platform with
-            | Epic _ ->
-                Log.warn "Unable to re-launch game without fully restarting the launcher when using an Epic account"
-                return persistentProcesses @ relaunchProcesses, didLoop
-            | _ -> return! launchLoop false settings playableProducts (Some persistentProcesses) (Some relaunchProcesses) cancellationToken processArgs
+            return! launchLoop false settings playableProducts session (Some persistentProcesses) (Some relaunchProcesses) cancellationToken processArgs
         else
             return persistentProcesses @ relaunchProcesses, didLoop
 }
@@ -510,7 +520,7 @@ let run settings launcherVersion cancellationToken = taskResult {
     let gameLanguage = Cobra.getGameLang settings.CbLauncherDir settings.PreferredLanguage
     let processArgs = Product.createArgString settings.DisplayMode gameLanguage connection.Session machineId (getRunningTime()) settings.WatchForCrashes settings.Platform SHA1.hashFile
 
-    let! runningProcesses, didLoop = launchLoop true settings playableProducts None None cancellationToken processArgs
+    let! runningProcesses, didLoop = launchLoop true settings playableProducts connection.Session None None cancellationToken processArgs
 
     if settings.ShutdownDelay > TimeSpan.Zero then
         Log.info $"Delaying shutdown for %.2f{settings.ShutdownDelay.TotalSeconds} seconds"

src/MinEdLauncher/Epic.fs

@@ -1,6 +1,6 @@
 module MinEdLauncher.Epic
 
-open Types
+open FsToolkit.ErrorHandling
 open Rop
 open MinEdLauncher.Token
 open System
@@ -102,7 +102,7 @@ let private requestToStr formValues contentHeaders (request: HttpRequestMessage)
     |> Http.dumpHeaders [ request.Headers; contentHeaders ] 2
     sb.ToString()
 
-let private request launcherVersion (formValues: string list) : Task<Result<RefreshableToken, string>> =
+let private requestToken launcherVersion (formValues: string list) : Task<Result<RefreshableToken, string>> =
     match epicValues.Force() with
     | Ok (clientId, clientSecret, dId) -> task {
         let formValues =
@@ -131,11 +131,37 @@ let private request launcherVersion (formValues: string list) : Task<Result<Refr
             Log.debug $"Requesting epic token failed: %s{content}"
             return $"%i{int response.StatusCode}: %s{response.ReasonPhrase}" |> Error }
     | Error msg -> Error msg |> Task.fromResult
+
+let private requestAsEpic path applyOptions = task {
+    use httpClient = new HttpClient()
+    use request = new HttpRequestMessage()
+
+    applyOptions request
 
-let login launcherVersion epicDetails =             
-    request launcherVersion [ "grant_type=exchange_code"
-                              $"exchange_code=%s{epicDetails.ExchangeCode}" ]
+    request.RequestUri <- Uri($"https://account-public-service-prod03.ol.epicgames.com%s{path}")
+    request.Headers.TryAddWithoutValidation("User-Agent", "UELauncher/11.0.1-14907503+++Portal+Release-Live Windows/10.0.19041.1.256.64bit") |> ignore
+
+    return! httpClient.SendAsync(request)
+}
+
+let private generateExchangeCode token = task {
+    let! response = requestAsEpic "/account/api/oauth/exchange" (fun r -> r.Headers.Authorization <- AuthenticationHeaderValue("bearer", token))
+
+    if response.IsSuccessStatusCode then
+        Log.debug "Requesting epic exchange code success"
+        use! content = response.Content.ReadAsStreamAsync()
+        return content |> Json.parseStream >>= Json.rootElement >>= Json.parseProp "code" >>= Json.toString
+    else
+        let! content = response.Content.ReadAsStringAsync()
+        Log.debug $"Requesting epic exchange code failed: %s{content}"
+        return $"%i{int response.StatusCode}: %s{response.ReasonPhrase}" |> Error }
+
+let loginWithCode launcherVersion exchangeCode =             
+    requestToken launcherVersion [ "grant_type=exchange_code"; $"exchange_code=%s{exchangeCode}" ]
 
 let refreshToken launcherVersion (token: RefreshableToken) =
-    request launcherVersion [ "grant_type=refresh_token"
-                              $"refresh_token=%s{token.RefreshToken}" ]
+    requestToken launcherVersion [ "grant_type=refresh_token"; $"refresh_token=%s{token.RefreshToken}" ]
+
+let loginWithExistingToken launcherVersion token =
+    generateExchangeCode token
+    |> TaskResult.bind(loginWithCode launcherVersion) 

src/MinEdLauncher/Extensions.fs

@@ -157,7 +157,7 @@ module Json =
         | false, _ -> Error $"Unable to convert string to long '%s{str}'"
     let asDateTime (prop:JsonElement) =
         let str = prop.ToString()
-        match DateTime.TryParse(str) with
+        match DateTimeOffset.TryParse(str) with
         | true, value -> Ok value
         | false, _ -> Error $"Unable to parse string as DateTime '%s{str}'"
     let asUri (prop:JsonElement) =
@@ -166,6 +166,11 @@ module Json =
         | false, _ -> Error $"Unable to parse '%s{prop.ToString()}' as Uri"
     let toString (prop:JsonElement) =
         Ok <| prop.ToString()
+    let asString (prop:JsonElement) =
+        try
+            prop.GetString() |> Ok
+        with
+        | :? InvalidOperationException -> Error $"Unable to parse '%s{prop.ToString()}' as string"
     let asVersion (prop:JsonElement) =
         match Version.TryParse(prop.ToString()) with
         | true, value -> Ok value
@@ -454,15 +459,17 @@ module Environment =
         let appData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)
         Path.Combine(appData, AppFolderName, subDir)
 
-    let configDir =
+    let configDirFor name =
         let specialFolder =
             if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) then
                 Environment.SpecialFolder.LocalApplicationData
             else
                 Environment.SpecialFolder.ApplicationData
 
         let path = Environment.GetFolderPath(specialFolder)
-        Path.Combine(path, AppFolderName)
+        Path.Combine(path, name)
+
+    let configDir = configDirFor AppFolderName
 
     let cacheDir =
         if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) then

src/MinEdLauncher/Legendary.fs

@@ -0,0 +1,51 @@
+module Legendary
+
+open System
+open System.IO
+open System.Runtime.InteropServices
+open MinEdLauncher
+open FsToolkit.ErrorHandling
+open Rop
+
+let parseAccessToken (timeProvider: TimeProvider) json = result {
+    let! root = json |> Json.rootElement
+    do! root
+        |> Json.parseProp "expires_at"
+        >>= Json.asDateTime
+        >>= (fun expires -> expires > timeProvider.GetUtcNow()
+                            |> Result.requireTrue "Epic access token is expired. Re-authenticate with Legendary/Heroic")
+
+    return! root |> Json.parseProp "access_token" >>= Json.asString
+}
+
+let getAccessToken() =
+    let potentialPaths =
+        if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) then
+            [
+                Environment.GetEnvironmentVariable("LEGENDARY_CONFIG_PATH")
+                Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".config", "legendary")
+                Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "heroic", "legendaryConfig", "legendary")
+            ]
+        else if RuntimeInformation.IsOSPlatform(OSPlatform.Linux) then
+            [
+                Environment.GetEnvironmentVariable("LEGENDARY_CONFIG_PATH")
+                Environment.configDirFor "legendary"
+                Path.Combine(Environment.configDirFor "heroic", "legendaryConfig", "legendary")
+            ]
+        else
+            []
+        |> List.filter (fun p -> not (String.IsNullOrWhiteSpace(p)))
+
+    potentialPaths
+    |> List.map (fun p -> FileInfo(Path.Combine(p, "user.json")))
+    |> List.filter _.Exists
+    |> List.sortByDescending _.LastWriteTime // Assume newest file has latest access token
+    |> List.tryHead
+    |> Option.map _.FullName
+    |> Result.requireSome "Couldn't find Legendary auth file"
+    |> Result.teeError (fun _ ->
+        let paths = if potentialPaths.Length = 0 then "None" else String.Join($"{Environment.NewLine}    ", potentialPaths)
+        Log.debug $"Legendary locations checked:{Environment.NewLine}{paths}"
+    )
+    >>= Json.parseFile
+    >>= (parseAccessToken TimeProvider.System)

src/MinEdLauncher/MinEdLauncher.fsproj

@@ -55,6 +55,7 @@
     <Compile Include="Cobra.fs" />
     <Compile Include="Api.fs" />
     <Compile Include="MachineId.fs" />
+    <Compile Include="Legendary.fs" />
     <Compile Include="Epic.fs" />
     <Compile Include="Settings.fs" />
     <Compile Include="Console.fs" />

src/MinEdLauncher/Token.fs

@@ -3,6 +3,7 @@ module MinEdLauncher.Token
 open System
 open System.Threading.Tasks
 open System.Timers
+open FsToolkit.ErrorHandling
 
 type RefreshableToken =
         { Token: string
@@ -14,7 +15,7 @@ type private RefreshableTokenMessage =
     | Get of replyChannel: AsyncReplyChannel<RefreshableToken>
     | Refresh of RefreshableToken
 
-type RefreshableTokenManager(initialToken, refresh: (RefreshableToken -> Task<Result<RefreshableToken, string>>)) =
+type RefreshableTokenManager(initialToken, refresh: RefreshableToken -> Task<Result<RefreshableToken, string>>, renew: unit -> Task<Result<RefreshableToken, string>>) =
     let agent = MailboxProcessor.Start(fun inbox ->
         let rec loop token = async {
             match! inbox.Receive() with
@@ -38,22 +39,28 @@ type RefreshableTokenManager(initialToken, refresh: (RefreshableToken -> Task<Re
             timer.Start()
 
     member this.Get() = agent.PostAndReply Get
+    member this.Renew() = task {
+        return!
+            renew()
+            |> TaskResult.tee(fun t -> Refresh t |> agent.Post)
+            |> TaskResult.map(fun _ -> ())
+    }
     interface IDisposable with
         member _.Dispose() =
             timer.Dispose()
 
 type PasswordToken = { Username: string; Password: string; Token: string }
 type AuthToken =
-    | Expires of (unit -> RefreshableToken)
+    | Expires of {| Get: unit -> RefreshableToken; Renew: unit -> Task<Result<unit, string>> |}
     | Permanent of string
     | PasswordBased of PasswordToken
     member this.GetAccessToken() =
            match this with
-           | Expires t -> t().Token
+           | Expires t -> t.Get().Token
            | Permanent t -> t
            | PasswordBased t -> t.Token
     member this.GetRefreshToken() =
            match this with
-           | Expires t -> Some (t().RefreshToken)
+           | Expires t -> Some (t.Get().RefreshToken)
            | Permanent _ -> None
            | PasswordBased _ -> None