---
title: "Image Authentication in Prowler"
---

Prowler's Image provider enables container image security scanning using [Trivy](https://trivy.dev/). No authentication is required for public images. Prowler supports the following authentication methods for private registries:

* [**Basic Authentication (Environment Variables)**](https://trivy.dev/latest/docs/advanced/private-registries/docker-hub/): `REGISTRY_USERNAME` and `REGISTRY_PASSWORD`
* [**Token-Based Authentication**](https://distribution.github.io/distribution/spec/auth/token/): `REGISTRY_TOKEN`
* [**Manual Docker Login**](https://docs.docker.com/reference/cli/docker/login/): Existing credentials in Docker's credential store

Prowler uses the first available method in this priority order.

## Basic Authentication (Environment Variables)

To authenticate with a username and password, set the `REGISTRY_USERNAME` and `REGISTRY_PASSWORD` environment variables. Prowler passes these credentials to Trivy, which handles authentication with the registry transparently:

```bash
export REGISTRY_USERNAME="myuser"
export REGISTRY_PASSWORD="mypassword"

prowler image -I myregistry.io/myapp:v1.0
```

Both variables must be set for this method to activate.

## Token-Based Authentication

To authenticate using a registry token (such as a bearer or OAuth2 token), set the `REGISTRY_TOKEN` environment variable. Prowler passes the token directly to Trivy:

```bash
export REGISTRY_TOKEN="my-registry-token"

prowler image -I myregistry.io/myapp:v1.0
```

This method is useful for registries that support token-based access without requiring a username and password.

## Manual Docker Login (Fallback)

If no environment variables are set, Prowler relies on existing credentials in Docker's credential store (`~/.docker/config.json`). To configure credentials manually before scanning:

```bash
docker login myregistry.io

prowler image -I myregistry.io/myapp:v1.0
```

<Note>
This method is available in Prowler CLI only. In Prowler Cloud, use basic authentication or token-based authentication instead.
</Note>