Delphi DLL

S3 Get Bucket Policy

See more Amazon S3 (new) Examples

Demonstrates how to send a GET request to fetch the policy of a specified bucket. The following information is quoted from the AWS REST API reference documentation at http://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGETpolicy.html

To use this operation, you must have GetPolicy permissions on the specified bucket, and you must be the bucket owner.

If you don't have GetPolicy permissions, Amazon S3 returns a 403 Access Denied error. If you have the correct permissions, but you're not the bucket owner, Amazon S3 returns a 405 Method Not Allowed error. If the bucket does not have a policy, Amazon S3 returns a 404 Policy Not found error. There are restrictions about who can create bucket policies and which objects in a bucket they can apply to. For more information, go to Using Bucket Policies.

Important: This example requires Chilkat v9.5.0.66 or greater.

Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, AuthAws, Rest, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
rest: HCkRest;
bTls: Boolean;
port: Integer;
bAutoReconnect: Boolean;
authAws: HCkAuthAws;
responseJsonStr: PWideChar;
json: HCkJsonObject;

begin
success := False;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Important: This example requires Chilkat v9.5.0.66 or greater.

rest := CkRest_Create();

// Connect to the Amazon AWS REST server in the desired region.
bTls := True;
port := 443;
bAutoReconnect := True;
success := CkRest_Connect(rest,'s3-us-west-2.amazonaws.com',port,bTls,bAutoReconnect);

// Provide AWS credentials.
authAws := CkAuthAws_Create();
CkAuthAws_putAccessKey(authAws,'AWS_ACCESS_KEY');
CkAuthAws_putSecretKey(authAws,'AWS_SECRET_KEY');
CkAuthAws_putServiceName(authAws,'s3');

// This particular bucket is in the Oregon region, as opposed to the US Standard,
// therefore the Region must be set appropriately.
// Also note that we connected to "s3-us-west-2.amazonaws.com".
CkAuthAws_putRegion(authAws,'us-west-2');

success := CkRest_SetAuthAws(rest,authAws);

// Note: The above REST connection and setup of the AWS credentials
// can be done once.  After connecting, any number of REST calls can be made.
// The "auto reconnect" property passed to rest.Connect indicates that if
// the connection is lost, a REST method call will automatically reconnect
// if needed.
// --------------------------------------------------------------------------

// Set the bucket name via the HOST header.
// In this case, the bucket name is "chilkat.ocean".
// Note that the Host header should use "bucketName.s3.amazonaws.com", not "bucketName.s3-us-west-2.amazonaws.com"
CkRest_putHost(rest,'chilkat.ocean.s3.amazonaws.com');

// Get the policy.
responseJsonStr := CkRest__fullRequestNoBody(rest,'GET','/?policy');
if (CkRest_getLastMethodSuccess(rest) <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// When successful, the S3 Storage service will respond with a 200 response code,
// with an XML body.  
if (CkRest_getResponseStatusCode(rest) <> 200) then
  begin
    // Examine the request/response to see what happened.
    Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
    Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
    Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
    Memo1.Lines.Add('response body: ' + responseJsonStr);
    Memo1.Lines.Add('---');
    Memo1.Lines.Add('LastRequestStartLine: ' + CkRest__lastRequestStartLine(rest));
    Memo1.Lines.Add('LastRequestHeader: ' + CkRest__lastRequestHeader(rest));
  end;

Memo1.Lines.Add('response body: ' + responseJsonStr);

// Load the JSON and display in a more human-readable manner:
json := CkJsonObject_Create();
CkJsonObject_Load(json,responseJsonStr);
CkJsonObject_putEmitCompact(json,False);
Memo1.Lines.Add(CkJsonObject__emit(json));

// Sample output:

// 	{ 
// 	  "Version": "2012-10-17",
// 	  "Statement": [
// 	    { 
// 	      "Effect": "Allow",
// 	      "Resource": "arn:aws:s3.asp">chilkat.ocean/",
// 	      "Principal": "*"
// 	    }
// 	  ]
// 	}
// 

CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkJsonObject_Dispose(json);

end;