Amazon S3 files sharing - amazon-web-services

Question

In my project there is a need for creating share link for external users without aws user from my researching found out a couple ways for doing so
Bucket policy based on tag
Lambda that creates sign url every time some user request the file
The question is what is the best practice for doing so
I need the download to be available until the user sharing the file stopes it
Thank guys for any answers

Answer 1

Using the AWS SDK, you can use Amazon S3 Pre-sign functionality. You can perform this task in any of the supported programming languages (Java, JS, Python, etc).
The following code shows how to sign an object via the Amazon S3 Java V2 API.
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.time.Duration;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.presigner.model.GetObjectPresignRequest;
import software.amazon.awssdk.services.s3.presigner.model.PresignedGetObjectRequest;
import software.amazon.awssdk.services.s3.presigner.S3Presigner;
import software.amazon.awssdk.utils.IoUtils;
// snippet-end:[presigned.java2.getobjectpresigned.import]
/**
* To run this AWS code example, ensure that you have setup your development environment, including your AWS credentials.
*
* For information, see this documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class GetObjectPresignedUrl {
public static void main(String[] args) {
final String USAGE = "\n" +
"Usage:\n" +
" GetObjectPresignedUrl <bucketName> <keyName> \n\n" +
"Where:\n" +
" bucketName - the Amazon S3 bucket name. \n\n"+
" keyName - a key name that represents a text file. \n\n";
if (args.length != 2) {
System.out.println(USAGE);
System.exit(1);
}
String bucketName = args[0];
String keyName = args[1];
Region region = Region.US_WEST_2;
S3Presigner presigner = S3Presigner.builder()
.region(region)
.build();
getPresignedUrl(presigner, bucketName, keyName);
presigner.close();
}
// snippet-start:[presigned.java2.getobjectpresigned.main]
public static void getPresignedUrl(S3Presigner presigner, String bucketName, String keyName ) {
try {
GetObjectRequest getObjectRequest =
GetObjectRequest.builder()
.bucket(bucketName)
.key(keyName)
.build();
GetObjectPresignRequest getObjectPresignRequest = GetObjectPresignRequest.builder()
.signatureDuration(Duration.ofMinutes(10))
.getObjectRequest(getObjectRequest)
.build();
// Generate the presigned request
PresignedGetObjectRequest presignedGetObjectRequest =
presigner.presignGetObject(getObjectPresignRequest);
// Log the presigned URL
System.out.println("Presigned URL: " + presignedGetObjectRequest.url());
HttpURLConnection connection = (HttpURLConnection) presignedGetObjectRequest.url().openConnection();
presignedGetObjectRequest.httpRequest().headers().forEach((header, values) -> {
values.forEach(value -> {
connection.addRequestProperty(header, value);
});
});
// Send any request payload that the service needs (not needed when isBrowserExecutable is true)
if (presignedGetObjectRequest.signedPayload().isPresent()) {
connection.setDoOutput(true);
try (InputStream signedPayload = presignedGetObjectRequest.signedPayload().get().asInputStream();
OutputStream httpOutputStream = connection.getOutputStream()) {
IoUtils.copy(signedPayload, httpOutputStream);
}
}
// Download the result of executing the request
try (InputStream content = connection.getInputStream()) {
System.out.println("Service returned response: ");
IoUtils.copy(content, System.out);
}
} catch (S3Exception e) {
e.getStackTrace();
} catch (IOException e) {
e.getStackTrace();
}
// snippet-end:[presigned.java2.getobjectpresigned.main]
}
}