ASP.NET Core uses [HTTPS by default](~/security/enforcing-ssl.md). [HTTPS](https://en.wikipedia.org/wiki/HTTPS) relies on [certificates](https://en.wikipedia.org/wiki/Public_key_certificate) for trust, identity, and encryption.
See [Developing ASP.NET Core Applications with Docker over HTTPS](https://github.com/dotnet/dotnet-docker/blob/main/samples/run-aspnetcore-https-development.md) for development scenarios.
This sample requires [Docker 17.06](https://docs.docker.com/release-notes/docker-ce) or later of the [Docker client](https://www.docker.com/products/docker).
## Prerequisites
The [.NET Core 2.2 SDK](https://dotnet.microsoft.com/download) or later is required for some of the instructions in this document.
A certificate from a [certificate authority](https://wikipedia.org/wiki/Certificate_authority) is required for [production hosting](https://blogs.msdn.microsoft.com/webdev/2017/11/29/configuring-https-in-asp-net-core-across-different-platforms/) for a domain. [:::no-loc text="Let's Encrypt":::](https://letsencrypt.org/) is a certificate authority that offers free certificates.
This document uses [self-signed development certificates](https://wikipedia.org/wiki/Self-signed_certificate) for hosting pre-built images over `localhost`. The instructions are similar to using production certificates.
For production certificates:
* The `dotnet dev-certs` tool is not required.
* Certificates don't need to be stored in the location used in the instructions. Store the certificates in any location outside the site directory.
The instructions contained in the following section volume mount certificates into containers using the `volumes` property in *docker-compose.yml.* You could add certificates into container images with a `COPY` command in a *Dockerfile*, but it's not recommended. Copying certificates into an image isn't recommended for the following reasons:
* It makes it difficult to use the same image for testing with developer certificates.
* It makes it difficult to use the same image for Hosting with production certificates.
* There is significant risk of certificate disclosure.
## Starting a container with https support using docker compose
Use the following instructions for your operating system configuration.
`dotnet dev-certs https --trust` is only supported on macOS and Windows. You need to trust certificates on Linux in the way that is supported by your distribution. It is likely that you need to trust the certificate in your browser.