403 error when calling GetManifestAsync on suicide-restricted videos

[wasd52030]

Version

6.3.16

Platform

.NET 6.0.423/Windows 11

Steps to reproduce

using YoutubeExplode;
using YoutubeExplode.Videos.Streams;

var yt=new YoutubeClient();
var url="https://www.youtube.com/watch?v=4QXCPuwBz2E";

var videotManifest=await yt.Videos.Streams.GetManifestAsync(url);

Details

Expected Behavior: Returns valid StreamManifest
Actual Behavior: HttpRequestException thrown

Complete error repor

System.Net.Http.HttpRequestException: Response status code does not indicate success: 403 (Forbidden).
   at System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode()
   at YoutubeExplode.Videos.Streams.StreamClient.TryGetContentLengthAsync(IStreamData streamData, String url, CancellationToken cancellationToken) in /_/YoutubeExplode/Videos/Streams/StreamClient.cs:line 63
   at YoutubeExplode.Videos.Streams.StreamClient.GetStreamInfosAsync(IEnumerable`1 streamDatas, CancellationToken cancellationToken)+MoveNext() in /_/YoutubeExplode/Videos/Streams/StreamClient.cs:line 114
   at YoutubeExplode.Videos.Streams.StreamClient.GetStreamInfosAsync(IEnumerable`1 streamDatas, CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
   at YoutubeExplode.Utils.Extensions.AsyncCollectionExtensions.ToListAsync[T](IAsyncEnumerable`1 source) in /_/YoutubeExplode/Utils/Extensions/AsyncCollectionExtensions.cs:line 49
   at YoutubeExplode.Utils.Extensions.AsyncCollectionExtensions.ToListAsync[T](IAsyncEnumerable`1 source) in /_/YoutubeExplode/Utils/Extensions/AsyncCollectionExtensions.cs:line 49
   at YoutubeExplode.Videos.Streams.StreamClient.GetStreamInfosAsync(VideoId videoId, PlayerResponse playerResponse, CancellationToken cancellationToken) in /_/YoutubeExplode/Videos/Streams/StreamClient.cs:line 218
   at YoutubeExplode.Videos.Streams.StreamClient.GetStreamInfosAsync(VideoId videoId, CancellationToken cancellationToken) in /_/YoutubeExplode/Videos/Streams/StreamClient.cs:line 276
   at YoutubeExplode.Videos.Streams.StreamClient.GetManifestAsync(VideoId videoId, CancellationToken cancellationToken) in /_/YoutubeExplode/Videos/Streams/StreamClient.cs:line 292

Checklist

• I have looked through existing issues to make sure that this bug has not been reported before
• I have provided a descriptive title for this issue
• I have made sure that this bug is reproducible on the latest version of the package
• I have provided all the information needed to reproduce this bug as efficiently as possible
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• I have not read any of the above and just checked all the boxes to submit the issue

[wasd52030]

When I perform a large number of downloads at once, there is a higher probability of occurrences exceeding a certain threshold (greater than 50).

[Tyrrrz]

I can definitely see it happening on CI, but I don't have the time to investigate. Any help is welcome.

[dylansunny]

I think these Youtube videos need age confirmation. That's why the downloads are not accessible.

[wasd52030]

I think these Youtube videos need age confirmation. That's why the downloads are not accessible.

It displays a similar page
I knew from the start that this video was about suicide, but I just want to listen to the music

[Tyrrrz]

I had some time to investigate this issue, but unfortunately didn't come up with a solution. However, it seems that the deciphering process did not change and YoutubeExplode still performs that part correctly. My guess is that YouTube added a new form of verification for the TVHTML5 client (that we use for age-restricted videos), but I have not been able to reverse-engineer it yet.

[vadmium]

FYI I recently found that if stream URLs have an “n=. . .” query parameter, I have to transform the values or I get 403 responses. The transform function is in the player Java Script. To find the function, look where it is called, just after the .get("n") method call. For instance it is the yma function in the following.

yma = function(a) {
    var b = a.split("")
    /* . . . */
    return b.join("")
};
/* . . . */
(b = a.get("n"))
    && (b = yRa[0](b),
        a.set("n", b),
        yRa.length || yma(""))
/* . . . */
var yRa = [yma];

[Edit: discussion of the function from 2021: ytdl-org/youtube-dl#29326 (comment)]

[Tyrrrz]

Thanks @vadmium.

I remember previously the n parameter was only responsible for whether the downloads are throttled or not. Is it now required to access the stream altogether?

[Tyrrrz]

Another video test case: https://www.youtube.com/watch?v=vcw5THyM7Jo