How to fix error in AWS policy for AWS S3?

Question

I read https://repost.aws/knowledge-center/s3-invalid-principal-in-policy-error

I has

{
  "Id": "Policy1710830593816",
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Stmt1710830590440",
      "Action": "s3:*",
      "Effect": "Allow",
      "Resource": "arn:aws:s3:::ixxx2-station-data",
      "Principal": {
        "AWS":["arn:aws:iam::093297098997:M69-AWS-JXX-iCxxx-Developer/v_doxxx"]
      }
    }
  ]
}

(Some value changed for security)

How to fix?

Answer 1

ARNs for IAM roles should look something like arn:aws:iam::<account-id>:role/<role-name> and for IAM users, it should look something like arn:aws:iam::<account-id>:user/<user-name>.

So, if M69-AWS-JXX-iCxxx-Developer/v_doxxx is the name of your role/user, you'll want to adjust your policy to follow the format I mentioned above. Make sure the role/user name matches exactly what you've set up in AWS IAM, including any paths(I am curious as to why there is a path in your role name or user name) or special characters.

Your principal should look like:

"Principal": {
  "AWS": "arn:aws:iam::093297098997:role/M69-AWS-JXX-iCxxx-Developer/v_doxxx"
}

Again, double-check that the role name is correct and exists in your IAM, and you should be good to go.