# 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.


records = []
        for i, request in enumerate(data['TransactItems']):
            put_request = request.get('Put')
            if put_request:
                existing_item = self._thread_local('existing_items')[i]
                table_name = put_request['TableName']
                keys = dynamodb_extract_keys(item=put_request['Item'], table_name=table_name)
                if isinstance(keys, Response):
                    return keys
                new_record = clone(record)
                new_record['eventName'] = 'INSERT' if not existing_item else 'MODIFY'
                new_record['dynamodb']['Keys'] = keys
                new_record['dynamodb']['NewImage'] = put_request['Item']
                if existing_item:
                    new_record['dynamodb']['OldImage'] = existing_item
                new_record['eventSourceARN'] = aws_stack.dynamodb_table_arn(table_name)
                records.append(new_record)
            update_request = request.get('Update')
            if update_request:
                table_name = update_request['TableName']
                keys = update_request['Key']
                if isinstance(keys, Response):
                    return keys
                updated_item = find_existing_item(update_request, table_name)
                if not updated_item:
                    return
                new_record = clone(record)
                new_record['eventName'] = 'MODIFY'
                new_record['dynamodb']['Keys'] = keys
                new_record['dynamodb']['OldImage'] = self._thread_local('existing_items')[i]