We Keep Coding

VMProtect and webclient

I have a problem with protecting my soft with VMProtect.
url (with redirect)- no secerity, no SSL/TLS (HTML 1.1, http)
In Visual Studio I have no Errors (compiled, without protection).
WebClient webClient = new WebClient();
webClient.Headers.Add(HttpRequestHeader.UserAgent, Agent);
content = await webClient.DownloadStringTaskAsync(url);
With this code i have an error: The request was aborted. Could not create SSL/TLS connection
I tried to add (before and after new Weblicent()):
ServicePointManager.Expect100Continue = true;
ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11| SecurityProtocolType.Tls12 | SecurityProtocolType.Ssl3;
Also tried add only this:
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 (and with Ssl3)
Not worked: Eset antivirus blocking: MSIL/TrojanDownloader.Agent.LNO

Unable to make HttpWebRequest that is working on Postman

I have a token request that works on Postman on a server.
No body, just basic authentication with username and password:
However, I have this code below that returns the error:
The request was aborted: Could not create SSL/TLS secure channel.
Here is the code below:
string responsedata = string.Empty;
String encoded = System.Convert.ToBase64String(System.Text.Encoding.GetEncoding("ISO-8859-1").GetBytes(username + ":" + password));
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urlToken);
request.Method = "POST";
request.Headers.Add("Authorization", "Basic " + encoded);
request.PreAuthenticate = true;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
using (Stream stream = response.GetResponseStream())
using (StreamReader reader = new StreamReader(stream))
{
responsedata = reader.ReadToEnd();
}
What am I doing worng?

I suspect your problem is related to the SecurityProtocol your application runs on.
Try running this before your request.
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
The endpoint your trying to connect probably requires a higher version of Tls than what your application is providing.
The default value of this is defined by the system it runs on see:
https://learn.microsoft.com/en-us/dotnet/api/system.net.securityprotocoltype?view=net-7.0#system-net-securityprotocoltype-systemdefault
So when running on an older OS this often is too low for modern API endpoints.
You can test this by enabling or disabling specific versions of TLS/SSL in Postman, look for "Protocols disabled during handshake" in the settings tab for your request.

Like Neil Moss already commented above...
Think you are in use of untrusted certificate on server side so try to ignore certificate validation...
request.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;

SecurityProtocolType.Tls12 does not resolve the underlying connection was closed an unexpected error occurred on a send. (C#)

I deployed a WCF web service on IIS (https, TLS1.2) last year, 2019 and the client code implemented SecurityProtocolType.Tls12 , and it connected to the web service URL successfully and started working perfectly.
I ran into a problem this year saying
the underlying connection was closed. An unexpected error occurred on a send.
I checked the web service URL SSL certificate if it is still on TLS1.2, and it is.
The client code to test the connection is shown below:
public bool TestConnection(string url)
{
try
{
var myRequest = (HttpWebRequest)WebRequest.Create(url);
myRequest.Timeout = Timeout.Infinite;
myRequest.ReadWriteTimeout = 30000;
myRequest.KeepAlive = true;
myRequest.ServicePoint.Expect100Continue = false;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
myRequest.ServerCertificateValidationCallback = (s, cert, chain, ssl) => true;
var response = (HttpWebResponse)myRequest.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
return true;
}
else
{
//well, at least it returned...
return false;
}
}
catch (Exception ex)
{
return false;
}
}

I think the most possible cause is that the certificate is expired if the WCF service and the client-side work properly before.
Are you using a self-signed certificate for transport layer security? Also, please try not to specify a TLS version for communication.
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
Before we call the remote service again, I suggest you navigate to the service URL using a browser and check for certificate errors. The error message displayed by the browser should help you troubleshoot what's causing the error.
Feel free to let me know if the problem still exists.

C# - RestSharp - The request was aborted: Could not create SSL/TLS secure channel

I am trying invoke a REST web service using RestSharp.
Following is my code :
ServicePointManager.Expect100Continue = true;
ServicePointManager.DefaultConnectionLimit = 9999;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12 | SecurityProtocolType.Ssl3;
ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
var client = new RestClient(url);
var certificate = new X509Certificate();
certificate.Import(Properties.Resources.cert, "password", X509KeyStorageFlags.PersistKeySet);
client.ClientCertificates = new X509CertificateCollection() { certificate };
var request = new RestRequest(Method.POST);
request.AddHeader("Connection", "keep-alive");
request.AddHeader("Content-Type", "text/plain");
request.AddParameter("undefined", $"param={param}", ParameterType.RequestBody);
IRestResponse response = await client.ExecutePostTaskAsync(request);
return response;
However, I am getting error - The request was aborted: Could not create SSL/TLS secure channel.
I also tried searching about this error but in all of the posts people suggest to use - SecurityProtocolType.Tls12 and ServicePointManager.Expect100Continue = true.
I am already using these in my code, still I see the error. Also if I try to fire similar request using Postman it works fine.
Is there anything else that I am missing?

Found it. C# requires the cert to be imported in user store.
I was missing this part.
After importing the pfx to the user store, for the first request I was prompted for the allowing the request by OS, subsequent requests worked flawlessly.

The request was aborted: Could not create SSL/TLS secure channel HttpClient

I am trying to access a web api using below C# code :
private static CertificateContext authenticationContext;
authenticationContext = new CertificateContext(new Uri(endpoint), ThumbPrint);
var client = authenticationContext.GetHttpClient();
var response = await client.GetStringAsync(url);
It was working fine initially but later i am getting below error:
The request was aborted: Could not create SSL/TLS secure channel.
I checked some forums and as per the suggestions i tried with below options, but nothing worked for me
1.ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
2.ServicePointManager.ServerCertificateValidationCallback = delegate (object s, X509Certificate certificate, X509Chain chain,
SslPolicyErrors sslPolicyErrors) { return true; };
Kindly help me to fix this error. Thanks in advance