github: Use IAM Roles to push files on AWS S3

For security reasons long lived credentials are not considered secure.
To overcome this issue we can configure Github Workflows to use AWS OpenID Connect instead:
For further details: https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect

Author: alessio-perugini

.github/workflows/release.yml

@@ -11,6 +11,7 @@ env:
   PYTHON_VERSION: "3.7"
   MCUBOOT_PATH: ${{ github.workspace }}/mcuboot
   IMGTOOL_PACKING_PATH: ${{ github.workspace }}/imgtool-packing
+  AWS_REGION: "us-east-1"
 
 on:
   push:
@@ -265,7 +266,11 @@ jobs:
 
   create-release:
     runs-on: ubuntu-latest
+    environment: production
     needs: [build, build-crosscompile, notarize-macos]
+    permissions:
+      contents: write
+      id-token: write # This is required for requesting the JWT
 
     steps:
       - name: Checkout repository # we need package_index.template
@@ -323,12 +328,12 @@ jobs:
           # (all the files we need are in the DIST_DIR root)
           artifacts: ${{ env.DIST_DIR }}/*
 
+      - name: configure aws credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: ${{ secrets.AWS_ROLE_TO_ASSUME }}
+          role-session-name: "github_${{ env.PROJECT_NAME }}"
+          aws-region: ${{ env.AWS_REGION }}
+
       - name: Upload release files on Arduino downloads servers
-        uses: docker://plugins/s3
-        env:
-          PLUGIN_SOURCE: "${{ env.DIST_DIR }}/*"
-          PLUGIN_TARGET: ${{ env.AWS_PLUGIN_TARGET }}
-          PLUGIN_STRIP_PREFIX: "${{ env.DIST_DIR }}/"
-          PLUGIN_BUCKET: ${{ secrets.DOWNLOADS_BUCKET }}
-          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+        run: aws s3 sync ${{ env.DIST_DIR }} s3://${{ secrets.DOWNLOADS_BUCKET }}${{ env.AWS_PLUGIN_TARGET }}