Appendix A: The Access Policy Language

This appendix is for Amazon S3 users who want to write their own access control policies. You don't need to write your own policies if you want to allow access based only on AWS account ID and basic permissions. If you want to explicitly deny access or allow it based on finer conditions (like the time the request comes in or the IP address of the requester), you need to write your own policies and upload them to AWS.

	Note
	To write your own policies, you must be familiar with JSON. For more information, go to http://json.org.

The main portion of this appendix includes basic concepts you need to understand, how to write a policy, and the logic AWS uses to evaluate policies and decide whether to give the requester access to the resource. Although most of the information in this appendix is service-agnostic, there are some Amazon S3-specific details you need to know. For more information, see Special Information for Amazon S3 Policies.