Replicating encrypted objects (SSE-C, SSE-S3, SSE-KMS, DSSE-KMS)

Important

Amazon S3 now applies server-side encryption with Amazon S3 managed keys (SSE-S3) as the base level of encryption for every bucket in Amazon S3. Starting January 5, 2023, all new object uploads to Amazon S3 are automatically encrypted at no additional cost and with no impact on performance. The automatic encryption status for S3 bucket default encryption configuration and for new object uploads is available in AWS CloudTrail logs, S3 Inventory, S3 Storage Lens, the Amazon S3 console, and as an additional Amazon S3 API response header in the AWS Command Line Interface and AWS SDKs. For more information, see Default encryption FAQ.

There are some special considerations when you're replicating objects that have been encrypted by using server-side encryption. Amazon S3 supports the following types of server-side encryption:

• Server-side encryption with Amazon S3 managed keys (SSE-S3)

• Server-side encryption with AWS Key Management Service (AWS KMS) keys (SSE-KMS)

• Dual-layer server-side encryption with AWS KMS keys (DSSE-KMS)

• Server-side encryption with customer-provided keys (SSE-C)

For more information about server-side encryption, see Protecting data with server-side encryption.

This topic explains the permissions that you need to direct Amazon S3 to replicate objects that have been encrypted by using server-side encryption. This topic also provides additional configuration elements that you can add and example AWS Identity and Access Management (IAM) policies that grant the necessary permissions for replicating encrypted objects.

For an example with step-by-step instructions, see Enabling replication for encrypted objects. For information about creating a replication configuration, see Replicating objects overview.

Note

You can use multi-Region AWS KMS keys in Amazon S3. However, Amazon S3 currently treats multi-Region keys as though they were single-Region keys, and does not use the multi-Region features of the key. For more information, see Using multi-Region keys in AWS Key Management Service Developer Guide.

How default bucket encryption affects replication

When you enable default encryption for a replication destination bucket, the following encryption behavior applies:

• If objects in the source bucket are not encrypted, the replica objects in the destination bucket are encrypted by using the default encryption settings of the destination bucket. As a result, the entity tags (ETags) of the source objects differ from the ETags of the replica objects. If you have applications that use ETags, you must update those applications to account for this difference.

• If objects in the source bucket are encrypted by using server-side encryption with Amazon S3 managed keys (SSE-S3), server-side encryption with AWS Key Management Service (AWS KMS) keys (SSE-KMS), or dual-layer server-side encryption with AWS KMS keys (DSSE-KMS), the replica objects in the destination bucket use the same type of encryption as the source objects. The default encryption settings of the destination bucket are not used.

Replicating objects encrypted with SSE-C

By using server-side encryption with customer-provided keys (SSE-C), you can manage your own proprietary encryption keys. With SSE-C, you manage the keys while Amazon S3 manages the encryption and decryption process. You must provide an encryption key as part of your request, but you don't need to write any code to perform object encryption or decryption. When you upload an object, Amazon S3 encrypts the object by using the key that you provided. Amazon S3 then purges that key from memory. When you retrieve an object, you must provide the same encryption key as part of your request. For more information, see Using server-side encryption with customer-provided keys (SSE-C).

S3 Replication supports objects that are encrypted with SSE-C. You can configure SSE-C object replication in the Amazon S3 console or with the AWS SDKs, the same way that you configure replication for unencrypted objects. There aren't additional SSE-C permissions beyond what are currently required for replication.

S3 Replication automatically replicates newly uploaded SSE-C encrypted objects if they are eligible, as specified in your S3 Replication configuration. To replicate existing objects in your buckets, use S3 Batch Replication. For more information about replicating objects, see Setting up live replication and Replicating existing objects with S3 Batch Replication.

There are no additional charges for replicating SSE-C objects. For details about replication pricing, see the Amazon S3 pricing page.

Replicating objects encrypted with SSE-S3, SSE-KMS, or DSSE-KMS

By default, Amazon S3 doesn't replicate objects that are encrypted with SSE-KMS or DSSE-KMS. This section explains the additional configuration elements that you can add to direct Amazon S3 to replicate these objects.

For an example with step-by-step instructions, see Enabling replication for encrypted objects. For information about creating a replication configuration, see Replicating objects overview.

Specifying additional information in the replication configuration

In the replication configuration, you do the following:

• In the Destination element in your replication configuration, add the ID of the symmetric AWS KMS customer managed key that you want Amazon S3 to use to encrypt object replicas, as shown in the following example replication configuration.

• Explicitly opt in by enabling replication of objects encrypted by using KMS keys (SSE-KMS or DSSE-KMS). To opt in, add the SourceSelectionCriteria element, as shown in the following example replication configuration.

<ReplicationConfiguration>
   <Rule>
      ...
      <SourceSelectionCriteria>
         <SseKmsEncryptedObjects>
           <Status>Enabled</Status>
         </SseKmsEncryptedObjects>
      </SourceSelectionCriteria>

      <Destination>
          ...
          <EncryptionConfiguration>
             <ReplicaKmsKeyID>AWS KMS key ARN or Key Alias ARN that's in the same AWS Region as the destination bucket.</ReplicaKmsKeyID>
          </EncryptionConfiguration>
       </Destination>
      ...
   </Rule>
</ReplicationConfiguration>

Important

The KMS key must have been created in the same AWS Region as the destination buckets.

The KMS key must be valid. The PutBucketReplication API operation doesn't check the validity of KMS keys. If you use a KMS key that isn't valid, you will receive the HTTP 200 OK status code in response, but replication fails.

The following example shows a replication configuration that includes optional configuration elements. This replication configuration has one rule. The rule applies to objects with the Tax key prefix. Amazon S3 uses the specified AWS KMS key ID to encrypt these object replicas.

<?xml version="1.0" encoding="UTF-8"?>
<ReplicationConfiguration>
   <Role>arn:aws:iam::account-id:role/role-name</Role>
   <Rule>
      <ID>Rule-1</ID>
      <Priority>1</Priority>
      <Status>Enabled</Status>
      <DeleteMarkerReplication>
         <Status>Disabled</Status>
      </DeleteMarkerReplication>
      <Filter>
         <Prefix>Tax</Prefix>
      </Filter>
      <Destination>
         <Bucket>arn:aws:s3:::example-s3-destination-bucket</Bucket>
         <EncryptionConfiguration>
            <ReplicaKmsKeyID>AWS KMS key ARN or Key Alias ARN that's in the same AWS Region as the destination bucket. (S3 uses this key to encrypt object replicas.)</ReplicaKmsKeyID>
         </EncryptionConfiguration>
      </Destination>
      <SourceSelectionCriteria>
         <SseKmsEncryptedObjects>
            <Status>Enabled</Status>
         </SseKmsEncryptedObjects>
      </SourceSelectionCriteria>
   </Rule>
</ReplicationConfiguration>

Granting additional permissions for the IAM role

To replicate objects that are encrypted at rest by using SSE-S3, SSE-KMS, or DSSE-KMS, grant the following additional permissions to the AWS Identity and Access Management (IAM) role that you specify in the replication configuration. You grant these permissions by updating the permissions policy that's associated with the IAM role.

• s3:GetObjectVersionForReplication action for source objects – This action allows Amazon S3 to replicate both unencrypted objects and objects created with server-side encryption by using SSE-S3, SSE-KMS, or DSSE-KMS.

  Note

  We recommend that you use the s3:GetObjectVersionForReplication action instead of the s3:GetObjectVersion action because s3:GetObjectVersionForReplication provides Amazon S3 with only the minimum permissions necessary for replication. In addition, the s3:GetObjectVersion action allows replication of unencrypted and SSE-S3-encrypted objects, but not of objects that are encrypted by using KMS keys (SSE-KMS or DSSE-KMS).

• kms:Decrypt and kms:Encrypt AWS KMS actions for the KMS keys

  • You must grant kms:Decrypt permissions for the AWS KMS key that's used to decrypt the source object.

  • You must grant kms:Encrypt permissions for the AWS KMS key that's used to encrypt the object replica.

• kms:GenerateDataKey action for replicating plaintext objects – If you're replicating plaintext objects to a bucket with SSE-KMS or DSSE-KMS encryption enabled by default, you must include the kms:GenerateDataKey permission for the destination encryption context and the KMS key in the IAM policy.

We recommend that you restrict these permissions only to the destination buckets and objects by using AWS KMS condition keys. The AWS account that owns the IAM role must have permissions for the kms:Encrypt and kms:Decrypt actions for the KMS keys that are listed in the policy. If the KMS keys are owned by another AWS account, the owner of the KMS keys must grant these permissions to the AWS account that owns the IAM role. For more information about managing access to these KMS keys, see Using IAM Policies with AWS KMS in the AWS Key Management Service Developer Guide.

S3 Bucket Keys and replication

To use replication with an S3 Bucket Key, the AWS KMS key policy for the KMS key that's used to encrypt the object replica must include the kms:Decrypt permission for the calling principal. The call to kms:Decrypt verifies the integrity of the S3 Bucket Key before using it. For more information, see Using an S3 Bucket Key with replication.

When an S3 Bucket Key is enabled for the source or destination bucket, the encryption context will be the bucket's Amazon Resource Name (ARN), not the object's ARN (for example, arn:aws:s3:::bucket_ARN). You must update your IAM policies to use the bucket ARN for the encryption context:

"kms:EncryptionContext:aws:s3:arn": [
"arn:aws:s3:::bucket_ARN"
]

For more information, see Encryption context (x-amz-server-side-encryption-context) (in the "Using the REST API" section) and Changes to note before enabling an S3 Bucket Key.

Example policies – Using SSE-S3 and SSE-KMS with replication

The following example IAM policies show statements for using SSE-S3 and SSE-KMS with replication.

Example – Using SSE-KMS with separate destination buckets

The following example policy shows statements for using SSE-KMS with separate destination buckets.

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Action": ["kms:Decrypt"],
         "Effect": "Allow",
         "Condition": {
             "StringLike": {
                  "kms:ViaService": "s3.source-bucket-region.amazonaws.com",
                  "kms:EncryptionContext:aws:s3:arn": [
                      "arn:aws:s3:::example-s3-source-bucket/key-prefix1*"
                  ]
             }
          },
          "Resource": [
             "List of AWS KMS key ARNs that are used to encrypt source objects." 
          ]
      },
      {
         "Action": ["kms:Encrypt"],
         "Effect": "Allow",
         "Condition": {
            "StringLike": {
               "kms:ViaService": "s3.destination-bucket-1-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn": [
                  "arn:aws:s3:::example-s3-destination-bucket1/key-prefix1*"
               ]
         }
         },
         "Resource": [
            "AWS KMS key ARNs (in the same AWS Region as destination bucket 1). Used to encrypt object replicas created in destination bucket 1." 
         ]
      },
      {
         "Action": ["kms:Encrypt"],
         "Effect": "Allow",
         "Condition": {
            "StringLike": {
               "kms:ViaService": "s3.destination-bucket-2-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn": [
                  "arn:aws:s3:::example-s3-destination-bucket2/key-prefix1*"
               ]
         }
         },
         "Resource": [
            "AWS KMS key ARNs (in the same AWS Region as destination bucket 2). Used to encrypt object replicas created in destination bucket 2."
         ]
      }
   ]
}

Example – Replicating objects created with SSE-S3 and SSE-KMS

The following is a complete IAM policy that grants the necessary permissions to replicate unencrypted objects, objects created with SSE-S3, and objects created with SSE-KMS.

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:GetReplicationConfiguration",
            "s3:ListBucket"
         ],
         "Resource":[
            "arn:aws:s3:::example-s3-source-bucket"
         ]
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:GetObjectVersionForReplication",
            "s3:GetObjectVersionAcl"
         ],
         "Resource":[
            "arn:aws:s3:::example-s3-source-bucket/key-prefix1*"
         ]
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:ReplicateObject",
            "s3:ReplicateDelete"
         ],
         "Resource":"arn:aws:s3:::example-s3-destination-bucket/key-prefix1*"
      },
      {
         "Action":[
            "kms:Decrypt"
         ],
         "Effect":"Allow",
         "Condition":{
            "StringLike":{
               "kms:ViaService":"s3.source-bucket-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn":[
                  "arn:aws:s3:::example-s3-source-bucket/key-prefix1*"
               ]
            }
         },
         "Resource":[
           "List of the AWS KMS key ARNs that are used to encrypt source objects."
         ]
      },
      {
         "Action":[
            "kms:Encrypt"
         ],
         "Effect":"Allow",
         "Condition":{
            "StringLike":{
               "kms:ViaService":"s3.destination-bucket-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn":[
                  "arn:aws:s3:::example-s3-destination-bucket/prefix1*"
               ]
            }
         },
         "Resource":[
            "AWS KMS key ARNs (in the same AWS Region as the destination bucket) to use for encrypting object replicas"
         ]
      }
   ]
}

Example – Replicating objects with S3 Bucket Keys

The following is a complete IAM policy that grants the necessary permissions to replicate objects with S3 Bucket Keys.

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:GetReplicationConfiguration",
            "s3:ListBucket"
         ],
         "Resource":[
            "arn:aws:s3:::example-s3-source-bucket"
         ]
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:GetObjectVersionForReplication",
            "s3:GetObjectVersionAcl"
         ],
         "Resource":[
            "arn:aws:s3:::example-s3-source-bucket/key-prefix1*"
         ]
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:ReplicateObject",
            "s3:ReplicateDelete"
         ],
         "Resource":"arn:aws:s3:::example-s3-destination-bucket/key-prefix1*"
      },
      {
         "Action":[
            "kms:Decrypt"
         ],
         "Effect":"Allow",
         "Condition":{
            "StringLike":{
               "kms:ViaService":"s3.source-bucket-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn":[
                  "arn:aws:s3:::example-s3-source-bucket"
               ]
            }
         },
         "Resource":[
           "List of the AWS KMS key ARNs that are used to encrypt source objects."
         ]
      },
      {
         "Action":[
            "kms:Encrypt"
         ],
         "Effect":"Allow",
         "Condition":{
            "StringLike":{
               "kms:ViaService":"s3.destination-bucket-region.amazonaws.com",
               "kms:EncryptionContext:aws:s3:arn":[
                  "arn:aws:s3:::example-s3-destination-bucket"
               ]
            }
         },
         "Resource":[
            "AWS KMS key ARNs (in the same AWS Region as the destination bucket) to use for encrypting object replicas"
         ]
      }
   ]
}

Granting additional permissions for cross-account scenarios

In a cross-account scenario, where the source and destination buckets are owned by different AWS accounts, you can use a KMS key to encrypt object replicas. However, the KMS key owner must grant the source bucket owner permission to use the KMS key.

Note

If you need to replicate SSE-KMS data cross-account, then your replication rule must specify a customer managed key from AWS KMS for the destination account. AWS managed keys don't allow cross-account use, and therefore can't be used to perform cross-account replication.

To grant the source bucket owner permission to use the KMS key (AWS KMS console)

1. Sign in to the AWS Management Console and open the AWS KMS console at https://console.aws.amazon.com/kms.

2. To change the AWS Region, use the Region selector in the upper-right corner of the page.

3. To view the keys in your account that you create and manage, in the navigation pane choose Customer managed keys.

4. Choose the KMS key.

5. Under the General configuration section, choose the Key policy tab.

6. Scroll down to Other AWS accounts.

7. Choose Add other AWS accounts.

   The Other AWS accounts dialog box appears.

8. In the dialog box, choose Add another AWS account. For arn:aws:iam::, enter the source bucket account ID.

9. Choose Save changes.

To grant the source bucket owner permission to use the KMS key (AWS CLI)

• For information about the put-key-policy AWS Command Line Interface (AWS CLI) command, see put-key-policy in the AWS CLI Command Reference. For information about the underlying PutKeyPolicy API operation, see PutKeyPolicy in the AWS Key Management Service API Reference.

AWS KMS transaction quota considerations

When you add many new objects with AWS KMS encryption after enabling Cross-Region Replication (CRR), you might experience throttling (HTTP 503 Service Unavailable errors). Throttling occurs when the number of AWS KMS transactions per second exceeds the current quota. For more information, see Quotas in the AWS Key Management Service Developer Guide.

To request a quota increase, use Service Quotas. For more information, see Requesting a quota increase. If Service Quotas isn't supported in your Region, open an AWS Support case.

Enabling replication for encrypted objects

By default, Amazon S3 doesn't replicate objects that are encrypted by using server-side encryption with AWS Key Management Service (AWS KMS) keys (SSE-KMS) or dual-layer server-side encryption with AWS KMS keys (DSSE-KMS). To replicate objects encrypted with SSE-KMS or DSS-KMS, you must modify the bucket replication configuration to tell Amazon S3 to replicate these objects. This example explains how to use the Amazon S3 console and the AWS Command Line Interface (AWS CLI) to change the bucket replication configuration to enable replicating encrypted objects.

For more information, see Replicating encrypted objects (SSE-C, SSE-S3, SSE-KMS, DSSE-KMS).

Note

When an S3 Bucket Key is enabled for the source or destination bucket, the encryption context will be the bucket's Amazon Resource Name (ARN), not the object's ARN. You must update your IAM policies to use the bucket ARN for the encryption context. For more information, see S3 Bucket Keys and replication.

Note

You can use multi-Region AWS KMS keys in Amazon S3. However, Amazon S3 currently treats multi-Region keys as though they were single-Region keys, and does not use the multi-Region features of the key. For more information, see Using multi-Region keys in AWS Key Management Service Developer Guide.

Using the S3 console

For step-by-step instructions, see Configuring replication for source and destination buckets owned by the same account. This topic provides instructions for setting a replication configuration when the buckets are owned by the same and different AWS accounts.

Using the AWS CLI

To replicate encrypted objects with the AWS CLI, you do the following:

• Create source and destination buckets and enable versioning on these buckets.

• Create an AWS Identity and Access Management (IAM) service role that gives Amazon S3 permission to replicate objects. The IAM role's permissions include the necessary permissions to replicate the encrypted objects.

• Add a replication configuration to the source bucket. The replication configuration provides information related to replicating objects that are encrypted by using KMS keys.

• Add encrypted objects to the source bucket.

• Test the setup to confirm that your encrypted objects are being replicated to the destination bucket.

The following procedures walk you through this process.

To replicate server-side encrypted objects (AWS CLI)

1. In this example, you create both the example-s3-source-bucket and example-s3-destination-bucket buckets in the same AWS account. You also set a credentials profile for the AWS CLI. This example uses the profile name acctA.

   For more information about setting credential profiles, see Named Profiles in the AWS Command Line Interface User Guide. To use the commands in this example, replace the user input placeholders with your own information.

2. Use the following commands to create the DOC-EXAMPLE-SOURCE-BUCKET bucket and enable versioning on it. The following example commands create the DOC-EXAMPLE-SOURCE-BUCKET bucket in the US East (N. Virginia) (us-east-1) Region.

   aws s3api create-bucket \
   --bucket DOC-EXAMPLE-SOURCE-BUCKET \
   --region us-east-1 \
   --profile acctA

   aws s3api put-bucket-versioning \
   --bucket DOC-EXAMPLE-SOURCE-BUCKET \
   --versioning-configuration Status=Enabled \
   --profile acctA

3. Use the following commands to create the DOC-EXAMPLE-DESTINATION-BUCKET bucket and enable versioning on it. The following example commands create the DOC-EXAMPLE-DESTINATION-BUCKET bucket in the US West (Oregon) (us-west-2) Region.

   Note

   To set up a replication configuration when both DOC-EXAMPLE-SOURCE-BUCKET and DOC-EXAMPLE-DESTINATION-BUCKET buckets are in the same AWS account, you use the same profile. In this example, we use acctA. To configure replication when the buckets are owned by different AWS accounts, you specify different profiles for each.

   aws s3api create-bucket \
   --bucket DOC-EXAMPLE-DESTINATION-BUCKET \
   --region us-west-2 \
   --create-bucket-configuration LocationConstraint=us-west-2 \
   --profile acctA

   aws s3api put-bucket-versioning \
   --bucket DOC-EXAMPLE-DESTINATION-BUCKET \
   --versioning-configuration Status=Enabled \
   --profile acctA

4. Next, you create an IAM service role. You will specify this role in the replication configuration that you add to the DOC-EXAMPLE-SOURCE-BUCKET bucket later. Amazon S3 assumes this role to replicate objects on your behalf. You create an IAM role in two steps:

   • Create a service role.

   • Attach a permissions policy to the role.

   1. To create an IAM service role, do the following:

      1. Copy the following trust policy and save it to a file called s3-role-trust-policy-kmsobj.json in the current directory on your local computer. This policy grants Amazon S3 service principal permissions to assume the role so that Amazon S3 can perform tasks on your behalf.

         {
            "Version":"2012-10-17",
            "Statement":[
               {
                  "Effect":"Allow",
                  "Principal":{
                     "Service":"s3.amazonaws.com"
                  },
                  "Action":"sts:AssumeRole"
               }
            ]
         }

      2. Use the following command to create the role:

         $ aws iam create-role \
         --role-name replicationRolekmsobj \
         --assume-role-policy-document file://s3-role-trust-policy-kmsobj.json  \
         --profile acctA

   2. Next, you attach a permissions policy to the role. This policy grants permissions for various Amazon S3 bucket and object actions.

      1. Copy the following permissions policy and save it to a file named s3-role-permissions-policykmsobj.json in the current directory on your local computer. You will create an IAM role and attach the policy to it later.

         Important

         In the permissions policy, you specify the AWS KMS key IDs that will be used for encryption of the example-s3-source-bucket and example-s3-destination-bucket buckets. You must create two separate KMS keys for the example-s3-source-bucket and example-s3-destination-bucket buckets. AWS KMS keys are not shared outside the AWS Region in which they were created.

         {
            "Version":"2012-10-17",
            "Statement":[
               {
                  "Action":[
                     "s3:ListBucket",
                     "s3:GetReplicationConfiguration",
                     "s3:GetObjectVersionForReplication",
                     "s3:GetObjectVersionAcl",
                     "s3:GetObjectVersionTagging"
                  ],
                  "Effect":"Allow",
                  "Resource":[
                     "arn:aws:s3:::example-s3-source-bucket",
                     "arn:aws:s3:::example-s3-source-bucket/*"
                  ]
               },
               {
                  "Action":[
                     "s3:ReplicateObject",
                     "s3:ReplicateDelete",
                     "s3:ReplicateTags"
                  ],
                  "Effect":"Allow",
                  "Condition":{
                     "StringLikeIfExists":{
                        "s3:x-amz-server-side-encryption":[
                           "aws:kms",
                           "AES256",
                           "aws:kms:dsse"
                        ],
                        "s3:x-amz-server-side-encryption-aws-kms-key-id":[
                           "AWS KMS key IDs(in ARN format) to use for encrypting object replicas"  
                        ]
                     }
                  },
                  "Resource":"arn:aws:s3:::example-s3-destination-bucket/*"
               },
               {
                  "Action":[
                     "kms:Decrypt"
                  ],
                  "Effect":"Allow",
                  "Condition":{
                     "StringLike":{
                        "kms:ViaService":"s3.us-east-1.amazonaws.com",
                        "kms:EncryptionContext:aws:s3:arn":[
                           "arn:aws:s3:::example-s3-source-bucket/*"
                        ]
                     }
                  },
                  "Resource":[
                     "AWS KMS key IDs(in ARN format) used to encrypt source objects." 
                  ]
               },
               {
                  "Action":[
                     "kms:Encrypt"
                  ],
                  "Effect":"Allow",
                  "Condition":{
                     "StringLike":{
                        "kms:ViaService":"s3.us-west-2.amazonaws.com",
                        "kms:EncryptionContext:aws:s3:arn":[
                           "arn:aws:s3:::example-s3-destination-bucket/*"
                        ]
                     }
                  },
                  "Resource":[
                     "AWS KMS key IDs(in ARN format) to use for encrypting object replicas" 
                  ]
               }
            ]
         }

      2. Create a policy and attach it to the role.

         $ aws iam put-role-policy \
         --role-name replicationRolekmsobj \
         --policy-document file://s3-role-permissions-policykmsobj.json \
         --policy-name replicationRolechangeownerPolicy \
         --profile acctA

5. Next, add the following replication configuration to the example-s3-source-bucket bucket. It tells Amazon S3 to replicate objects with the Tax/ prefix to the example-s3-destination-bucket bucket.

   Important

   In the replication configuration, you specify the IAM role that Amazon S3 can assume. You can do this only if you have the iam:PassRole permission. The profile that you specify in the CLI command must have this permission. For more information, see Granting a user permissions to pass a role to an AWS service in the IAM User Guide.

    <ReplicationConfiguration>
     <Role>IAM-Role-ARN</Role>
     <Rule>
       <Priority>1</Priority>
       <DeleteMarkerReplication>
          <Status>Disabled</Status>
       </DeleteMarkerReplication>
       <Filter>
          <Prefix>Tax</Prefix>
       </Filter>
       <Status>Enabled</Status>
       <SourceSelectionCriteria>
         <SseKmsEncryptedObjects>
           <Status>Enabled</Status>
         </SseKmsEncryptedObjects>
       </SourceSelectionCriteria>
       <Destination>
         <Bucket>arn:aws:s3:::example-s3-destination-bucket</Bucket>
         <EncryptionConfiguration>
           <ReplicaKmsKeyID>AWS KMS key IDs to use for encrypting object replicas</ReplicaKmsKeyID>
         </EncryptionConfiguration>
       </Destination>
     </Rule>
   </ReplicationConfiguration>

   To add a replication configuration to the example-s3-source-bucket bucket, do the following:

   1. The AWS CLI requires you to specify the replication configuration as JSON. Save the following JSON in a file (replication.json) in the current directory on your local computer.

      {
         "Role":"IAM-Role-ARN",
         "Rules":[
            {
               "Status":"Enabled",
               "Priority":1,
               "DeleteMarkerReplication":{
                  "Status":"Disabled"
               },
               "Filter":{
                  "Prefix":"Tax"
               },
               "Destination":{
                  "Bucket":"arn:aws:s3:::example-s3-destination-bucket",
                  "EncryptionConfiguration":{
                     "ReplicaKmsKeyID":"AWS KMS key IDs (in ARN format) to use for encrypting object replicas"
                  }
               },
               "SourceSelectionCriteria":{
                  "SseKmsEncryptedObjects":{
                     "Status":"Enabled"
                  }
               }
            }
         ]
      }

   2. Edit the JSON to provide values for the example-s3-destination-bucket bucket, AWS KMS key IDs (in ARN format), and IAM-role-ARN. Save the changes.

   3. Use the following command to add the replication configuration to your example-s3-source-bucket bucket. Be sure to provide the example-s3-source-bucket bucket name.

      $ aws s3api put-bucket-replication \
      --replication-configuration file://replication.json \
      --bucket example-s3-source-bucket \
      --profile acctA

6. Test the configuration to verify that encrypted objects are replicated. In the Amazon S3 console, do the following:

   1. Sign in to the AWS Management Console and open the Amazon S3 console at https://console.aws.amazon.com/s3/.

   2. In the example-s3-source-bucket bucket, create a folder named Tax.

   3. Add sample objects to the folder. Be sure to choose the encryption option and specify your KMS key to encrypt the objects.

   4. Verify that the example-s3-destination-bucket bucket contains the object replicas and that they are encrypted by using the KMS key that you specified in the configuration. For more information, see Getting replication status information.

Using the AWS SDKs

For a code example that shows how to add a replication configuration, see Using the AWS SDKs. You must modify the replication configuration appropriately.

For conceptual information, see Replicating encrypted objects (SSE-C, SSE-S3, SSE-KMS, DSSE-KMS).