# Acceso a los datos de S3 mediante credenciales que suministran las concesiones de acceso a S3
<a name="access-grants-get-data"></a>

Una vez que el beneficiario [obtiene las credenciales temporales](https://docs.aws.amazon.com/AmazonS3/latest/userguide/access-grants-credentials.html) mediante su concesión de acceso, puede utilizarlas para llamar a las operaciones de la API de Amazon S3 para acceder a sus datos. 

Los beneficiarios pueden obtener acceso a los datos de S3 a través de AWS Command Line Interface (AWS CLI), los SDK de AWS y la API de REST de Amazon S3. Además, puede usar los complementos de AWS [Python](https://github.com/aws/boto3-s3-access-grants-plugin) y [Java](https://github.com/aws/aws-s3-accessgrants-plugin-java-v2) para llamar a las concesiones de acceso a S3

## Uso de AWS CLI
<a name="access-grants-get-data-cli"></a>

Una vez que el beneficiario obtiene sus credenciales temporales de S3 Access Grants, puede configurar un perfil con estas credenciales para recuperar los datos. 

Para instalar AWS CLI, consulte [Instalación de AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html) en la *Guía del usuario de AWS Command Line Interface*.

Para utilizar los comandos de ejemplo siguientes, sustituya `user input placeholders` con su información.

**Example — Configurar un perfil**  

```
aws configure set aws_access_key_id "$accessKey" --profile access-grants-consumer-access-profile
aws configure set aws_secret_access_key "$secretKey" --profile access-grants-consumer-access-profile
aws configure set aws_session_token "$sessionToken" --profile access-grants-consumer-access-profile
```

Para utilizar el comando de ejemplo siguiente, sustituya `user input placeholders` con su información.

**Example – Obtener los datos de S3**  
El beneficiario puede usar el comando [https://docs.aws.amazon.com/cli/latest/reference/s3api/get-object.html](https://docs.aws.amazon.com/cli/latest/reference/s3api/get-object.html)AWS CLI para acceder a los datos. El beneficiario también puede usar [https://docs.aws.amazon.com/cli/latest/reference/s3api/put-object.html](https://docs.aws.amazon.com/cli/latest/reference/s3api/put-object.html), [https://docs.aws.amazon.com/cli/latest/reference/s3/ls.html](https://docs.aws.amazon.com/cli/latest/reference/s3/ls.html) y otros comandos de la AWS CLI de S3.   

```
aws s3api get-object \
--bucket amzn-s3-demo-bucket1 \
--key myprefix \
--region us-east-2 \
--profile access-grants-consumer-access-profile
```

## Uso de los AWS SDK
<a name="access-grants-get-data-using-sdk"></a>

En esta sección se proporcionan ejemplos de cómo los beneficiarios pueden acceder a sus datos de S3 mediante los SDK de AWS.

------
#### [ Java ]

En el ejemplo de código de Java siguiente se obtiene un objeto de un bucket de S3. Para obtener instrucciones sobre cómo crear y probar una muestra funcional, consulte [Introducción](https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/getting-started.html) en la *Guía para desarrolladores de AWS SDK para Java*.

```
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ResponseHeaderOverrides;
import com.amazonaws.services.s3.model.S3Object;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class GetObject2 {

    public static void main(String[] args) throws IOException {
        Regions clientRegion = Regions.DEFAULT_REGION;
        String bucketName = "*** Bucket name ***";
        String key = "*** Object key ***";

        S3Object fullObject = null, objectPortion = null, headerOverrideObject = null;
        try {
            AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                    .withRegion(clientRegion)
                    .withCredentials(new ProfileCredentialsProvider())
                    .build();

            // Get an object and print its contents.
            System.out.println("Downloading an object");
            fullObject = s3Client.getObject(new GetObjectRequest(bucketName, key));
            System.out.println("Content-Type: " + fullObject.getObjectMetadata().getContentType());
            System.out.println("Content: ");
            displayTextInputStream(fullObject.getObjectContent());

            // Get a range of bytes from an object and print the bytes.
            GetObjectRequest rangeObjectRequest = new GetObjectRequest(bucketName, key)
                    .withRange(0, 9);
            objectPortion = s3Client.getObject(rangeObjectRequest);
            System.out.println("Printing bytes retrieved.");
            displayTextInputStream(objectPortion.getObjectContent());

            // Get an entire object, overriding the specified response headers, and print
            // the object's content.
            ResponseHeaderOverrides headerOverrides = new ResponseHeaderOverrides()
                    .withCacheControl("No-cache")
                    .withContentDisposition("attachment; filename=example.txt");
            GetObjectRequest getObjectRequestHeaderOverride = new GetObjectRequest(bucketName, key)
                    .withResponseHeaders(headerOverrides);
            headerOverrideObject = s3Client.getObject(getObjectRequestHeaderOverride);
            displayTextInputStream(headerOverrideObject.getObjectContent());
        } catch (AmazonServiceException e) {
            // The call was transmitted successfully, but Amazon S3 couldn't process
            // it, so it returned an error response.
            e.printStackTrace();
        } catch (SdkClientException e) {
            // Amazon S3 couldn't be contacted for a response, or the client
            // couldn't parse the response from Amazon S3.
            e.printStackTrace();
        } finally {
            // To ensure that the network connection doesn't remain open, close any open
            // input streams.
            if (fullObject != null) {
                fullObject.close();
            }
            if (objectPortion != null) {
                objectPortion.close();
            }
            if (headerOverrideObject != null) {
                headerOverrideObject.close();
            }
        }
    }

    private static void displayTextInputStream(InputStream input) throws IOException {
        // Read the text input stream one line at a time and display each line.
        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        String line = null;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        System.out.println();
    }
}
```

------

## Acciones de S3 compatibles en concesiones de acceso a S3
<a name="access-grants-s3-actions"></a>

Un beneficiario puede usar la credencial temporal que entregan las concesiones de acceso a S3 para realizar acciones de S3 en los datos de S3 a los que tiene acceso. A continuación, se muestra una lista de las acciones de S3 permitidas que un beneficiario puede realizar. Las acciones permitidas dependen del nivel de permiso otorgado en la concesión de acceso, ya sea `READ`, `WRITE` o `READWRITE`. 

**nota**  
Además de los permisos de Amazon S3 que se indican a continuación, Amazon S3 puede llamar al permiso `READ` de AWS Key Management Service (AWS KMS) [Descifrar](https://docs.aws.amazon.com/kms/latest/APIReference/API_Decrypt.html) (`kms:decrypt`) o al permiso `WRITE` de AWS KMS [GenerateDataKey](https://docs.aws.amazon.com/kms/latest/APIReference/API_GenerateDataKey.html) (`kms:generateDataKey`). Estos permisos no permiten el acceso directo a la clave de AWS KMS.


****  

| Acción de IAM de S3 | Acción y documentación de la API | Permiso de concesiones de acceso a S3 | Recurso de S3 | 
| --- | --- | --- | --- | 
| s3:GetObject | [GetObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html) | READ | Objeto | 
| s3:GetObjectVersion | [GetObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html) | READ | Objeto | 
| s3:GetObjectAcl | [GetObjectAcl](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObjectAcl.html) | READ | Objeto | 
| s3:GetObjectVersionAcl | [GetObjectAcl](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObjectAcl.html) | READ | Objeto | 
| s3:ListMultipartUploads | [ListParts](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListParts.html) | READ | Objeto | 
| s3:PutObject | [PutObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObject.html), [CreateMultipartUpload](https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateMultipartUpload.html), [UploadPart](https://docs.aws.amazon.com/AmazonS3/latest/API/API_UploadPart.html), [UploadPartCopy](https://docs.aws.amazon.com/AmazonS3/latest/API/API_UploadPartCopy.html), [CompleteMultipartUpload](https://docs.aws.amazon.com/AmazonS3/latest/API/API_CompleteMultipartUpload.html) | WRITE | Objeto | 
| s3:PutObjectAcl | [PutObjectAcl](https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObjectAcl.html) | WRITE | Objeto | 
| s3:PutObjectVersionAcl | [PutObjectAcl](https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObjectAcl.html) | WRITE | Objeto | 
| s3:DeleteObject | [DeleteObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_DeleteObject.html) | WRITE | Objeto | 
| s3:DeleteObjectVersion | [DeleteObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_DeleteObject.html) | WRITE | Objeto | 
| s3:AbortMultipartUpload | [AbortMultipartUpload](https://docs.aws.amazon.com/AmazonS3/latest/API/API_AbortMultipartUpload.html) | WRITE | Objeto | 
| s3:ListBucket | [HeadBucket](https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadBucket.html), [ListObjectsV2](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectsV2.html), [ListObjects](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjects.html) | READ | Bucket | 
| s3:ListBucketVersions | [ListObjectVersions](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectVersions.html) | READ | Bucket | 
| s3:ListBucketMultipartUploads | [ListMultipartUploads](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListMultipartUploads.html) | READ | Bucket |