How to Create Secure IAM Policy for Connection to S3 Object Storage

Challenge

How to create a secure IAM policy to connect to the S3 bucket where backup data is to be stored (Veeam Backup Object Repository).

Solution

There are two policies to choose from. The first policy is for use when immutability is not used for the cloud tier. The second policy is for use when immutability is used for the cloud tier.

Use the following JSON for non-immutable buckets (make sure to replace the <yourbucketname> tag with the actual name) to create an IAM Policy by following the instructions from the How to Create IAM Policy article. These permissions will allow Veeam Backup Service to access the S3 repository to save/load data to/from an object repository. 

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "SecureBucketPolicy0",
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket",
                "s3:PutObject",
                "s3:GetObject",
                "s3:DeleteObject",
                "s3:GetBucketLocation",
                "s3:GetBucketVersioning",
                "s3:GetBucketObjectLockConfiguration"
            ],
            "Resource": [
                "arn:aws:s3:::<yourbucketname>/*",
                "arn:aws:s3:::<yourbucketname>"
            ]
        },
        {
            "Sid": "SecureBucketPolicy1",
            "Effect": "Allow",
            "Action": [
                "s3:ListAllMyBuckets",
                "s3:HeadBucket"
            ],
            "Resource": "*"
        }
    ]
}

Use the following JSON for immutable buckets (make sure to replace the <yourbucketname> tag with the actual name) to create an IAM Policy by following the instructions from the How to Create IAM Policy article. These permissions will allow Veeam Backup Service to access the S3 repository to save/load data to/from an object repository. 

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket",
                "s3:GetBucketLocation",
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject",
                "s3:GetBucketVersioning",
                "s3:GetBucketObjectLockConfiguration",
                "s3:ListBucketVersions",
                "s3:GetObjectVersion",
                "s3:GetObjectRetention",
                "s3:GetObjectLegalHold",
                "s3:PutObjectRetention",
                "s3:PutObjectLegalHold",
                "s3:DeleteObjectVersion"
            ],
            "Resource": [
                "arn:aws:s3:::<yourbucketname>/*",
                "arn:aws:s3:::<yourbucketname>"
            ]
        },
        {
            "Sid": "VisualEditor1",
            "Effect": "Allow",
            "Action": [
                "s3:ListAllMyBuckets",
                "s3:HeadBucket"
            ],
            "Resource": "*"
        }
    ]
}

More Information

IAM Policy creation instructions - https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create-console.html
Veeam Help Center reference - https://helpcenter.veeam.com/docs/backup/vsphere/required_permissions.html?ver=100