C# Rest Api TLS/SSL Connection Error

This is a dotnet error caused by your server configuration.

A google search for "The remote certificate is invalid according to the validation procedure" returned a tonne of possible answers, including this Stack Overflow post: c# - The remote certificate is invalid according to the validation procedure - Stack Overflow

But when I run the project on localhost, I cannot access the safe. Are you still saying it's due to the same reason? By the way, my domain name starts with http.

First of all, thank you very much for your interest. I found the cause of the error. The error is caused by Restsharp removing the MFWSClient method from the relevant version. However, when I tried other versions, I saw that there was no relevant method. How can I find a solution to this problem?

Restsharp Version: 106.12.0

MFaaP.MFWSClient Version: 1.3.0-alpha

Now I'm getting this error message:

System.MissingMethodException: 'Method not found: 'Void RestSharp.RestClient..ctor(System.Uri)'.'

I'm not sure the two are related.  The error was very specific.  I think you've upgraded the RestSharp project reference whilst testing this.  By changing the referenced version of RestSharp you've managed to reference a version that doesn't have a constructor that the library expects, thus causing that error.  I strongly suspect that even if you solve this specific issue you'll be back where you were.

That said: it appears you're using the MFWSClient sample.  Please note:

• This library is not official, and has no direct support.
• Feel free to open an issue on the github repository: GitHub - M-Files/Libraries.MFWSClient: An example .NET wrapper for the M-Files Web Service.  Please include a full project that reproduces the issue so that we can see the exact packages you're referencing.
• Note that the version you're using is relatively old.  Try:
  • Update the version of the package to the latest one.
  • Either do not explicitly target RestSharp or, if you have to, ensure you target the exact version that the project uses (108.0.2).

Ok I solved the problem. I think it's exactly Restsharp SSL error. To prevent this, I wrote the code that ignores the SSL error and also updated the MFaaP.MFWSClient library I was using to its latest version. Thanks very much for your help.

I would strongly recommend fixing the SSL issue rather than use a workaround that suppresses the SSL issue. 

But glad you have fixed it 

Yes, the solution I found is a temporary solution. I am also looking for a permanent solution. Do you have any advice as a permanent solution?

Yes: someone needs to identify the SSL issue and fix it.  You could use the link at the start of the thread as a starting point.

Ok I understand. I wonder if it is the people from Restsharp who will bring a solution to this issue? Who should find a solution when I ask a question from the link you shared? Or should I contact them directly?

I don't know what to say to you, as I feel I've said it all before.

I don't believe that the issue is with the MFWSClient library itself.  I don't believe that the issue is in RestSharp.  I believe the issue is with your infrastructure there.  I would assume that identifying and fixing the issue will be down to you and whoever administers the infrastructure.

Obviously feel free to create an issue on the RestSharp github project if you disagree with me.

Show me the code that you used to ignore the SSL error.  Maybe that'll convince me that it's a bug somewhere else, but I suspect you've simply told dotnet to ignore the SSL validation.

My code that I use to ignore ssl errors is as follows. 

ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;

My code that I use to ignore ssl errors is as follows. 

ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;

Yep; so you've told dotnet to ignore the SSL errors.

This further indicates to me that the issue is your infrastructure - as I said in the first post - and nothing to do with either library.

My M-Files login code with the MFWSClient library is as follows. If the error is in my infrastructure, then can you help me find out where the problem is? I'm still new to this.

public MFWSClient ConnectClient()

{
ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;
string baseUrl = @System.Configuration.ConfigurationManager.AppSettings["baseUrl"];
string vaultId = @System.Configuration.ConfigurationManager.AppSettings["vaultId"];
string username = @System.Configuration.ConfigurationManager.AppSettings["username"];
string password = @System.Configuration.ConfigurationManager.AppSettings["password"];
MFWSClient client = new MFWSClient(baseUrl);
client.AuthenticateUsingCredentialsAsync(Guid.Parse(vaultId), username, password);
return client;
}

Go to the link I sent in the very first post.  The top answer there has details of many reasons why you may get this error.  They include the certificate having expired, or that something in the chain isn't trusted, and a variety of other reasons.  Send that to the administrator of the infrastructure and work with them.

There is nothing more we can do to assist; you need to get someone to look into that issue and resolve it, at which point the problem disappears.

I know I took up a lot of your time, but I apologize and want to ask one more question. I was able to run this project very well before and access all the data I wanted. This is a situation that develops later and suddenly. If it was something related to my build, shouldn't I have gotten the same error before? Do you have any ideas about this issue?

I really don't know what else to say, so I think this is probably going to be my last post on this thread.  Maybe someone else can give you some other guidance.

What you're describing makes complete sense if you read the link I sent you in the very first post.

One of the potential issues in the link is that the SSL certificate has expired.  That would entirely explain why you didn't have an issue but you do now.  Another potential issue in the link is that the SSL certificate chain can't be validated/trusted, which might be caused when the SSL certificate were renewed and reapplied depending upon the certification authority that was used.  That would also entirely explain why you didn't have an issue but you do now.  Another potential issue in the link is self-signed certificates (which is related to the certification chain being unable to be valdiated/trusted), potentially as part of a renewal process.  That would also entirely explain why you didn't have an issue but you do now.

You need to speak to someone actually involved in the infrastructure there.  Someone who, perhaps, has changed something (or needs to change something) to do with the SSL certificate.  There is nothing more we can do to assist.  You need to get someone to look into the SSL issue and resolve it, at which point the problem disappears.