# Type of request: This is a ...
[ ] bug report
[x] feature request

# Detailed description
As a Developer,
I want to be able to simulate BadDigest and InvalidDigest errors,
So that I can test the error handling logic

## Expected behavior
https://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
BadDigest: The Content-MD5 you specified did not match what we received.
InvalidDigest: The Content-MD5 you specified is not valid.

## Actual behavior
localstack returns InvalidDigest when MD5 does not match payload.


body = {'Code': '200'}
    exists, code = bucket_exists(bucket_name)
    if not exists:
        body = {
            'Error': {
                'Code': code,
                'Message': 'The bucket does not exist'
            }
        }
        return exists, code, body
    return True, 200, body
def bucket_exists(bucket_name):
    """Tests for the existence of the specified bucket. Returns the error code
    if the bucket does not exist (200 if the bucket does exist).
    """
    bucket_name = normalize_bucket_name(bucket_name)
    s3_client = aws_stack.connect_to_service('s3')
    try:
        s3_client.head_bucket(Bucket=bucket_name)
    except ClientError as err:
        error_code = err.response.get('Error').get('Code')
        return False, error_code
    return True, 200
def check_content_md5(data, headers):