IdHTTP basic authentication access violation

Question

I'm trying to do a HTTP Authentication with Indy HTTP class. But for some unknown reason I'm getting an Access Violation error in this line: IdHTTP1.Request.Authentication.Username := Username;

The code stretch is:

  IdHTTP1:= TIdHttp.Create(Application);
  IdHTTP1.ConnectTimeout:= 10000;
  IdHTTP1.Request.Clear;
  IdHTTP1.Request.BasicAuthentication:= true;
  IdHTTP1.Request.Authentication.Username := Username;
  IdHTTP1.Request.Authentication.Password := Password;
      try
        IdHTTP1.Get(PbxURL);
        HttpCode := IdHTTP1.ResponseCode;
      except
        on E: EIdHTTPProtocolException do
          HttpCode := IdHTTP1.ResponseCode;

I'm using Delphi 2010, and already tried to do something like: IdHTTP1.Request.Authentication.Username := 'admin'; but didn't solved the problem...

When you say "access violation" or "error" or "exception", you need to tell us **what** the error or AV or exception is (the **exact** error message, including any memory addresses or error codes). We can't see your screen from where we are, so if you don't tell us, we don't know. (Based on the limited info you've provided, you're getting an error trying to write to `00000000`, which means there's no object instance created for `IdHTTP1.Request.Authentication`.) — Ken White, Sep 15 '12 at 20:50
Okay, first thing is: when i'm running the .exe outside the compiler/debugger, it don't shows me any error, just don't work... but when i'm debugging, I get this error: **Project Project1.exe raised exception class EAccessViolation with message 'Access violation at address 0051AC50 in module 'Project1.exe'. Read of address 00000000'.** — HwTrap, Sep 15 '12 at 20:54
Just as I said; there's no `Request.Authentication` object instance created. See my answer. — Ken White, Sep 15 '12 at 20:57

Ken White · Accepted Answer · 2014-05-01T18:00:47.067

21

From a quick check, it appears that there is no IdHTTP.Request.Authentication needed (and therefore none is created) when the Request.BasicAuthentication is true. You should be using Request.UserName and Request.Password instead.

IdHTTP1:= TIdHttp.Create(Application);
IdHTTP1.ConnectTimeout:= 10000;
IdHTTP1.Request.Clear;
IdHTTP1.Request.BasicAuthentication:= true;
IdHTTP1.Request.UserName := UserName;
IdHTTP1.Request.Password := Password;

edited May 01 '14 at 18:00

answered Sep 15 '12 at 20:56

Ken White

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It's looking like it working now, but that's something strange, in other application, I have **IdHTTP1.Request.Authentication.Username** and it works properly. And I'm creating same objects in same order than in this project... – HwTrap Sep 15 '12 at 21:04
It can't be working with `Request.Authentication.Username` if you're using basic authentication in the other app, if everything else is the same. Are the versions of Indy the same in both apps? – Ken White Sep 15 '12 at 21:50

score 3 · Answer 2 · answered Sep 16 '12 at 03:17

By default, the Request.Authentication object is not allocated until a request has been sent and an authentication response has been received, then the OnSelectAuthorization event is triggered to determine which class type to allocate for the object for subsequent requests..

The only other way the Request.Authentication object can be allocated is if you do it manually in your own code before sending a request, such as if you know ahead of time which auth scheme the server uses without sending a request to discover that dynamically.

IdHTTP basic authentication access violation

2 Answers2