C# SQL Server CLR Request error on functions GET and POST

I followed the GitHub documentation to implement the http requests with the CURL extension, work in SQL Server 2008 R2, Visual Studio 2010 and .NET 3.5.

I managed to compile and sign correctly the .dll in visual studio, to then create the schemas and functions in SQL Server, since everything works correctly, I can perform GET and POST from SQL Server, however, when wanting to perform a GET or a POST at SABA API, it generates a series of errors.

A .NET Framework error occurred during execution of user-defined routine or aggregate "XGET": System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Received an unexpected EOF or 0 bytes from the transport stream. System.IO.IOException: at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count) at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.CheckCompletionBeforatextReceive(ProtocolTokat message, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.StartSatdBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.ForceAuthattication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.ProcessAuthattication(LazyAsyncResult lazyResult) at System.Net.TlsStream.CallProcessAuthattication(Object state) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Net.TlsStream.ProcessAuthattication(LazyAsyncResult result)
at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size) at System.Net.PooledStream.Write(Byte[] buffer, Int32 offset, Int32 size) at System.Net.ConnectStream.WriteHeaders(Boo ... System.Net.WebException: at System.Net.WebCliatt.DownloadDataInternal(Uri address, WebRequest& request) at System.Net.WebCliatt.DownloadString(Uri address) ...

This is the code of the Assembly

using Microsoft.SqlServer.Server;
using System;
using System.Data.SqlTypes;
using System.Net;
using System.Threading;

public static class Curl
{
    [SqlFunction]
    [return: SqlFacet(MaxSize = -1)]
    public static SqlChars Get(SqlChars H, SqlChars url)
    {
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;
        var client = new WebClient();
        AddHeader(H, client);

        return new SqlChars(
                client.DownloadString(
                    Uri.EscapeUriString(url.ToSqlString().Value)
                    ).ToCharArray());
    }

    [SqlProcedure]
    public static void Post(SqlChars H, SqlChars d, SqlChars url)
    {
        var client = new WebClient();
        AddHeader(H, client);
        if (d.IsNull)
            throw new ArgumentException("You must specify data that will be sent to the endpoint", "@d");
        var response =
                client.UploadString(
                    Uri.EscapeUriString(url.ToSqlString().Value),
                    d.ToSqlString().Value
                    );
        SqlContext.Pipe.Send("Request is executed. " + response);
    }

    [SqlProcedure]
    public static void PostWithRetry(SqlChars H, SqlChars d, SqlChars url)
    {
        var client = new WebClient();
        AddHeader(H, client);
        if (d.IsNull)
            throw new ArgumentException("You must specify data that will be sent to the endpoint", "@d");
        int i = RETRY_COUNT;
        string response = "";
        do try
            {
                response =
                        client.UploadString(
                            Uri.EscapeUriString(url.ToSqlString().Value),
                            d.ToSqlString().Value
                            );
                i = -1;
                break;
            }
            catch (Exception ex)
            {
                SqlContext.Pipe.Send("Error:\t" + ex.Message + ". Waiting " + DELAY_ON_ERROR + "ms.");
                i--;
                Thread.Sleep(DELAY_ON_ERROR);
            }
        while (i > 0);
        if (i == -1)
            SqlContext.Pipe.Send("Request is executed." + response);
    }

    static readonly int RETRY_COUNT = 3;
    static readonly int DELAY_ON_ERROR = 50;

    public static bool IsNullOrWhiteSpace(this string theString)
    {
        if (theString == null)
        {
            return false;
        }

        if (theString.Trim() == string.Empty)
        {
            return false;
        }
        return true;
    }

    private static void AddHeader(SqlChars H, WebClient client)
    {
        if (!H.IsNull)
        {
            string header = H.ToString();
            if (!IsNullOrWhiteSpace(header))
                client.Headers.Add(HttpRequestHeader.UserAgent, header);
        }
    }
};

And this how to use in SQL Query

declare @hkey nvarchar(4000) = 'SabaCertificate: 31336132353061666330315E235E756F6E6555E6261536974655E235E656E5F55535E235E536162615E235E24414021463393C69358BE384802BA1BBEAD3B4661862F193021435F7E28A30F7540FE661B9C5F30FDB06C';
declare @endpoint nvarchar(1000) = 'https://libertad-api.sabacloud.com/v1/location?count=10&startPage=1';
select curl.xget(@hkey, @endpoint)

I already test it in PostMan, entering the Header of SabaCertificate, and if it throws a result at me, however, when the certificate is not correct it also throws a response and it is not shown.

Bad Request Example:

{"errorCode":123,"errorMessage":"Invalid or expired Certificate"}

But it also does not give me the answer of the certificate error, that I have to change in my WebClient for this to work.

Added to this I think the certificate is too big because sometimes I get this error:

The identifier that starts with 'SabaCertificate: 31336132353061666330315E235E756F6E6555E6261536974655E235E656E5F55535E235E536162615E235E24414021463393C69358BE384802BA1BBEAD3B4661862F193021435F7E28A30F7540FE661B9C5F30FDB06C' is too long. Maximum length is 128.