从Delphi获取Instapaper OAuth访问令牌

Question

我在使用Overbyte的ICS套件从Instapaper api获得访问令牌时遇到了麻烦。奇怪的是，我能够使用Indy获得访问令牌。我使用的是Delphi XE2和ICS version 7。

出于调试目的，我使用固定字符串作为post数据和授权头。由于Indy代码可以工作，所以问题似乎与签名无关。

我想让这个工作与ICS…对于代码为什么不能工作有什么想法吗?我得到一个无效的签名错误(签名与期望值不匹配)。授权头和post body应该与我用Indy发送的内容相同，所以听起来像是与ICS请求有关。

这是Indy代码的工作(我得到oauth_token和oauth_token_secret返回)

var
  Params: TStringList;
  AuthHeader: STring;
  idHTTP: TIDHTTP;
  SSLIOHandler: TIdSSLIOHandlerSocketOpenSSL;
begin 
  idHTTP := TIDHTTP.Create(Self);
  SslIOHandler := TIdSSLIOHandlerSocketOpenSSL.Create(Self);
  idHTTP.IOHandler := SSLIOHandler;
  idHTTP.HTTPOptions := [];   
  Params := TStringList.Create;
  Params.Add('x_auth_mode=client_auth');
  Params.Add('x_auth_password=mypassword');
  Params.Add('x_auth_username=myusername%40gmail.com');
  idHTTP.Request.Host := 'https://www.instapaper.com';
  AuthHeader := 'Authorization: ' + 'OAuth oauth_consumer_key="myconsumerkey", oauth_nonce="BAFWMTGFXNXSTNKUENBC", oauth_signature_method="HMAC-SHA1", oauth_signature="sEfq8gHlHYfrmLy5u0kKBgTYmVA%3D", oauth_timestamp="1369669197", oauth_version="1.0"';
  idHTTP.request.CustomHeaders.Add(AuthHeader);
  Response := idHTTP.Post('https://www.instapaper.com/api/1/oauth/access_token', Params);
end;

以下是ICS代码失败(无效签名):

var
  PostData: AnsiString;
begin
  PostData := 'x_auth_mode=client_auth&x_auth_password=mypassword&x_auth_username=myusername%40gmail.com';
  SSLHTTPClient := TSslHttpCli.Create(nil);
  With SSLHTTPClient do
  begin
    RcvdStream         := TMemoryStream.Create;
    SendStream         := TMemoryStream.Create;
    SendStream.Seek(0, soFromBeginning);
    SendStream.Write(PostData[1], Length(PostData));
    SendStream.Seek(0, soFromBeginning);
    URL                := 'https://www.instapaper.com/api/1/oauth/access_token';
    OnRequestDone      := SSLHTTPClientRequestDone;
    OnBeforeHeaderSend := HTTPClientBeforeHeaderSend;    // add the authorization header
    SslContext := TSslContext.Create(SSLHTTPClient);
    PostAsync;
  end;
end;
procedure TInstapaperOAuth.HTTPClientBeforeHeaderSend(Sender: TObject; const Method: string; Headers: TStrings);
var
  Header: String;
begin
  Header := 'Authorization: ' + 'OAuth oauth_consumer_key="myconsumerkey", oauth_nonce="BAFWMTGFXNXSTNKUENBC", oauth_signature_method="HMAC-SHA1", oauth_signature="sEfq8gHlHYfrmLy5u0kKBgTYmVA%3D", oauth_timestamp="1369669197", oauth_version="1.0"';
  Headers.Add(Header);
end;

Answer 1

我接受上面的评论作为这个问题的答案。所以要解决这个问题，更新HTTPClientBeforeHeaderSend来替换主机记录，并添加oauth头:

procedure TInstapaperOAuth.HTTPClientBeforeHeaderSend(Sender: TObject; const Method: string; Headers: TStrings);
var
  Header: String;
  I: Integer;
begin
  Header := 'Authorization: ' + 'OAuth oauth_consumer_key="myconsumerkey", oauth_nonce="BAFWMTGFXNXSTNKUENBC", oauth_signature_method="HMAC-SHA1", oauth_signature="sEfq8gHlHYfrmLy5u0kKBgTYmVA%3D", oauth_timestamp="1369669197", oauth_version="1.0"';
  Headers.Add(Header);
  //=======================================
  //  find the host record and replace it
  //=======================================
  for I := 0 to Headers.Count - 1 do
  begin
    if pos('Host:',Headers.Strings[I]) > 0 then
    begin
      Headers.Strings[I] := 'Host: www.instapaper.com';
      break;
    end;
  end;
end;