Table of Contents

Class AmazonS3EncryptionClientV2

Namespace
Amazon.Extensions.S3.Encryption
Assembly
Amazon.Extensions.S3.Encryption.dll

This class extends the AmazonS3Client and implements IAmazonS3Encryption Provides client side encryption when reading or writing S3 objects. Supported content ciphers: AES/GCM - Encryption and decryption (Encrypted block size can be bigger than the input block size) AES/CBC - Decryption only

public class AmazonS3EncryptionClientV2 : AmazonS3EncryptionClientBase, IAmazonS3, IDisposable, ICoreAmazonS3, IAmazonService, IAmazonS3Encryption
Inheritance
AmazonS3EncryptionClientV2
Implements

Constructors

AmazonS3EncryptionClientV2(AmazonS3CryptoConfigurationV2, EncryptionMaterialsV2) 

public AmazonS3EncryptionClientV2(AmazonS3CryptoConfigurationV2 config, EncryptionMaterialsV2 materials)

Parameters

config AmazonS3CryptoConfigurationV2
materials EncryptionMaterialsV2

AmazonS3EncryptionClientV2(AWSCredentials, AmazonS3CryptoConfigurationV2, EncryptionMaterialsV2) 

public AmazonS3EncryptionClientV2(AWSCredentials credentials, AmazonS3CryptoConfigurationV2 config, EncryptionMaterialsV2 materials)

Parameters

credentials AWSCredentials
config AmazonS3CryptoConfigurationV2
materials EncryptionMaterialsV2

AmazonS3EncryptionClientV2(string, string, AmazonS3CryptoConfigurationV2, EncryptionMaterialsV2) 

public AmazonS3EncryptionClientV2(string awsAccessKeyId, string awsSecretAccessKey, AmazonS3CryptoConfigurationV2 config, EncryptionMaterialsV2 materials)

Parameters

awsAccessKeyId string
awsSecretAccessKey string
config AmazonS3CryptoConfigurationV2
materials EncryptionMaterialsV2

AmazonS3EncryptionClientV2(string, string, string, AmazonS3CryptoConfigurationV2, EncryptionMaterialsV2) 

public AmazonS3EncryptionClientV2(string awsAccessKeyId, string awsSecretAccessKey, string awsSessionToken, AmazonS3CryptoConfigurationV2 config, EncryptionMaterialsV2 materials)

Parameters

awsAccessKeyId string
awsSecretAccessKey string
awsSessionToken string
config AmazonS3CryptoConfigurationV2
materials EncryptionMaterialsV2

Methods

CustomizeRuntimePipeline(RuntimePipeline)

Customize the pipeline

protected override void CustomizeRuntimePipeline(RuntimePipeline pipeline)

Parameters

pipeline RuntimePipeline

GetObject(GetObjectRequest)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override GetObjectResponse GetObject(GetObjectRequest request)

Parameters

request GetObjectRequest

Container for the necessary parameters to execute the GetObject service method.

Returns

GetObjectResponse

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also

GetObject(string, string)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override GetObjectResponse GetObject(string bucketName, string key)

Parameters

bucketName string

The bucket name containing the object. When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation using an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

key string

Key of the object to get.

Returns

GetObjectResponse

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also

GetObject(string, string, string)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override GetObjectResponse GetObject(string bucketName, string key, string versionId)

Parameters

bucketName string

The bucket name containing the object. When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation using an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

key string

Key of the object to get.

versionId string

VersionId used to reference a specific version of the object.

Returns

GetObjectResponse

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also

GetObjectAsync(GetObjectRequest, CancellationToken)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override Task<GetObjectResponse> GetObjectAsync(GetObjectRequest request, CancellationToken cancellationToken = default)

Parameters

request GetObjectRequest

Container for the necessary parameters to execute the GetObject service method.

cancellationToken CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Task<GetObjectResponse>

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also

GetObjectAsync(string, string, string, CancellationToken)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override Task<GetObjectResponse> GetObjectAsync(string bucketName, string key, string versionId, CancellationToken cancellationToken = default)

Parameters

bucketName string

The bucket name containing the object. When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation using an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

key string

Key of the object to get.

versionId string

VersionId used to reference a specific version of the object.

cancellationToken CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Task<GetObjectResponse>

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also

GetObjectAsync(string, string, CancellationToken)

Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

  • x-amz-server-side​-encryption​-customer-algorithm

  • x-amz-server-side​-encryption​-customer-key

  • x-amz-server-side​-encryption​-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 will return an HTTP status code 404 ("no such key") error.

  • If you don’t have the s3:ListBucket permission, Amazon S3 will return an HTTP status code 403 ("access denied") error.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

note

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

note

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

  • response-content-type

  • response-content-language

  • response-expires

  • response-cache-control

  • response-content-disposition

  • response-content-encoding

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject: 

public override Task<GetObjectResponse> GetObjectAsync(string bucketName, string key, CancellationToken cancellationToken = default)

Parameters

bucketName string

The bucket name containing the object. When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation using an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

key string

Key of the object to get.

cancellationToken CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Task<GetObjectResponse>

The response from the GetObject service method, as returned by S3.

Remarks

When decrypting with AES-GCM, read the entire object to the end before you start using the decrypted data. This is to verify that the object has not been modified since it was encrypted.

See Also