retrieve a json result from a https site - delphi

Question

How can I retrieve a JSON result from a HTTPS site?
I prefer a method to no need any DLL.
It show this error:
Error connecting with SSL.error:1409442E:SSL routines:ssl3_read_bytes:tlsv1 alert protocol version.
I'm using Delphi Tokyo 10.2.
function GetUrlContent(s: string): string;
var
IdHTTP1: TIdHTTP;
begin
IdHTTP1 := TIdHTTP.Create;
try
Result := IdHTTP1.Get(s);
finally
IdHTTP1.Free;
end;
end;
procedure GetData;
var
mydata, ordername: string;
begin
ordername := 'https://www.bitstamp.net/api/ticker/';
mydata := GetUrlContent(ordername);
DBMemo7.Text := mydata;
end;
I've also tried this, but it still gets the annoying SSL error:
function GetURLAsStrin1(const aurl: string): string;
var
res, req: String;
sList: TStringList;
IdHttp: TIdHttp;
begin
IdHttp := TIdHttp.Create (nil);
try
IdHttp.IOHandler := TIdSSLIOHandlerSocketOpenSSL.Create(IdHttp);
req := aurl;
res := IdHttp.Get (req);
result := res;
finally
idHttp.Free;
end;

Answer 1

By default, TIdSSLIOHandlerSocketOpenSSL enables only TLS 1.0. Most likely, the site in question does not support TLS 1.0 anymore. Try enabling TLS 1.1 and 1.2, eg:
function GetUrlContent(url: string): string;
var
IdHTTP1: TIdHTTP;
begin
IdHTTP1 := TIdHTTP.Create;
try
IO := TIdSSLIOHandlerSocketOpenSSL.Create(IdHTTP1);
IO.SSLOptions.SSLVersions := [sslvTLSv1, sslvTLSv1_1, sslvTLSv1_2] // <-- add this!
IdHttp.IOHandler := IO;
Result := IdHTTP1.Get(url);
finally
IdHTTP1.Free;
end;
end;

Answer 2

For newer delphi versions, I would recommend using the in-built HttpClient class. It does not require any external DLLs, and works for both http or https out of the box.
uses
System.Net.HttpClient;
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
Memo1.Text := GetUrlContent('https://www.bitstamp.net/api/ticker/');
end;
function TForm1.GetUrlContent(Url: string): string;
var
HttpClient: THttpClient;
Response: IHttpResponse;
begin
HttpClient := THTTPClient.Create;
try
Response := HttpClient.Get(URL);
Result := Response.ContentAsString();
finally
HttpClient.Free;
end;
end;