01 Define the access policy that enables the specified IAM users and/or roles to manage the new KMS Customer Master Key and to encrypt and decrypt tape data using the AWS KMS API. Create a new policy document, name it virtual-tape-cmk-policy.json, and paste the following content (replace the highlighted details, i.e. the ARNs for the IAM users and/or roles, with your own details): 
   
{
  "Version": "2012-10-17",
  "Id": "sg-volume-custom-key-policy",
  "Statement": [
    {
      "Sid": "Enable IAM User Permissions",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::123456789012:root"
      },
      "Action": "kms:*",
      "Resource": "*"
    },
    {
      "Sid": "Grant access to CMK manager",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::123456789012:role/SGTapeManager"
      },
      "Action": [
        "kms:Create*",
        "kms:Describe*",
        "kms:Enable*",
        "kms:List*",
        "kms:Put*",
        "kms:Update*",
        "kms:Revoke*",
        "kms:Disable*",
        "kms:Get*",
        "kms:Delete*",
        "kms:ScheduleKeyDeletion",
        "kms:CancelKeyDeletion"
      ],
      "Resource": "*"
    },
    {
      "Sid": "Allow the use of the CMK",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::123456789012:user/SGTapeAdmin"
      },
      "Action": [
        "kms:Encrypt",
        "kms:Decrypt",
        "kms:ReEncrypt*",
        "kms:GenerateDataKey*",
        "kms:DescribeKey"
      ],
      "Resource": "*"
    },
    {
      "Sid": "Allow attachment of persistent resources",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::123456789012:user/SGTapeAdmin"
      },
      "Action": [
        "kms:CreateGrant",
        "kms:ListGrants",
        "kms:RevokeGrant"
      ],
      "Resource": "*",
      "Condition": {
        "Bool": {
          "kms:GrantIsForAWSResource": "true"
        }
      }
    }
  ]
}
    02 Run create-key command (OSX/Linux/UNIX) using the file name of the policy document created at the previous step (i.e. virtual-tape-cmk-policy.json) as command parameter to create the new Amazon KMS CMK: 
   
aws kms create-key
    --region us-east-1
    --description 'KMS CMK for encrypting virtual tape data.'
    --policy file://virtual-tape-cmk-policy.json
    03 The command output should return the new KMS CMK metadata. Copy the key Amazon Resource Name (Arn parameter value - highlighted) as this information will be required later when you have to specify the key required for tape data encryption: 
   
{
    "KeyMetadata": {
        "Origin": "AWS_KMS",
        "KeyId": "abcd1234-abcd-1234-abcd-1234ancd1234",
        "Description": "KMS CMK for encrypting virtual tape data.",
        "Enabled": true,
        "KeyUsage": "ENCRYPT_DECRYPT",
        "KeyState": "Enabled",
        "CreationDate": 1517237395.290,
        "Arn": "arn:aws:kms:us-east-1:123456789012:key/abcd1234-abcd-1234-abcd-1234ancd1234",
        "AWSAccountId": "123456789012"
    }
}
    04 Run create-alias command (OSX/Linux/UNIX) using the key ARN returned at the previous step to add an alias to the new CMK. The alias must start with the prefix "alias/" (the command does not produce an output): 
   
aws kms create-alias
    --region us-east-1
    --alias-name alias/SGTapeCustomCMK
    --target-key-id arn:aws:kms:us-east-1:123456789012:key/abcd1234-abcd-1234-abcd-1234ancd1234
    05 Run create-tapes command (OSX/Linux/UNIX) to create a new virtual tape for the specified tape gateway. Use the ARN of the newly created Customer Master Key (CMK) as value for the --kms-key parameter, to configure data encryption using customer-managed keys: 
   
aws storagegateway create-tapes
    --region us-east-1
    --gateway-arn arn:aws:storagegateway:us-east-1:123456789012:gateway/sgw-12AB34CD
    --tape-size-in-bytes 161061273600
    --client-token AAAABBBB
    --num-tapes-to-create 2
    --tape-barcode-prefix ABC
    --kms-encrypted
    --kms-key arn:aws:kms:us-east-1:123456789012:key/abcd1234-abcd-1234-abcd-1234ancd1234
    06 The output should return the create-tapes command request metadata: 
   
{
    "TapeARNs": [
        "arn:aws:storagegateway:us-east-1:123456789012:tape/AABBCCDD0",
        "arn:aws:storagegateway:us-east-1:123456789012:tape/12340ABCD"
    ]
}
    07 Repeat step no. 5 to configure encryption at rest using AWS KMS Customer Master Keys for other Amazon Storage Gateway volumes available in the selected region. 
  08 Change the AWS region by updating the --region command parameter value and repeat steps no. 1 – 6 to perform the process for other regions.