onema

The problem here is that the user access key and secret you are using do not have the proper permission to access the bucket, therefore the AWS:Access Denied message.

I believe this has nothing to do with the plugin.

Normally I would create a user with permission to access the buckets I want to manage using wordpress.

NOTE: NEVER give a user more permissions than it requires.

The policies to allow a user to manage a single bucket would look like this (just replace MY_BUCKET_NAME with your actual bucket name):

{
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "s3:ListAllMyBuckets",
            "Resource": "arn:aws:s3:::*"
        },
        {
            "Effect": "Allow",
            "Action": "s3:*",
            "Resource": [
                "arn:aws:s3:::MY_BUCKET_NAME",
                "arn:aws:s3:::MY_BUCKET_NAME/*"
            ]
        }
    ]
}

See the following links for more information on how to set users and apply policies.

http://mikeferrier.com/2011/10/27/granting-access-to-a-single-s3-bucket-using-amazon-iam/

http://docs.aws.amazon.com/AmazonS3/latest/dev/walkthrough1.html

http://blogs.aws.amazon.com/security/post/TxPOJBY6FE360K/IAM-policies-and-Bucket-Policies-and-ACLs-Oh-My-Controlling-Access-to-S3-Resourc