Reduce third-party build script dependencies and reduce GITHUB_TOKEN perms in CI (#541)

* Reduce dependence on third-party build scripts in release pipeline

This removes one third-party build script from the release
pipeline for the release tar.gz, though one is still used in the
now-separate netlify deploy.

* Reduce GITHUB_TOKEN perms in actions when using 3rd party scripts

This avoids allowing third parties to arbitrarily overwrite the
repository.

* Replace PGP signing action with the bash script from the same

The PGP signing action ultimately just calls gpg with arguments
set in
https://github.com/actionhippie/gpgsign/blob/v1/overlay/usr/local/bin/entrypoint
so its rather trivial to simply take the required arguments and
put them directly in CI.

This is substantially safer than the PGP signing action used as the
action currently downloads, unverified and un-pinned, a docker
image in order to access PGP.

.github/workflows/deploy-pull-request.yml

@@ -6,6 +6,9 @@ on:
         - completed
 jobs:
   get-build-and-deploy:
+    permissions:
+      contents: read
+      pull-requests: write
     runs-on: ubuntu-latest
     if: >
       ${{ github.event.workflow_run.conclusion == 'success' }}

.github/workflows/netlify-dev.yml

@@ -9,7 +9,8 @@ jobs:
   deploy-to-netlify:
     name: 'Deploy'
     runs-on: ubuntu-latest
-
+    permissions:
+      contents: read
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3.0.2

.github/workflows/prod-deploy.yml

@@ -5,9 +5,43 @@ on:
     types: [published]
 
 jobs:
+  create-release:
+    name: 'Create release tar'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v3.0.2
+      - name: Build
+        run: |
+          npm ci
+          npm run build
+      - name: Get version from tag
+        id: vars
+        run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
+      - name: Create tar.gz
+        run: tar -czvf cinny-${{ steps.vars.outputs.tag }}.tar.gz dist
+      - name: Sign tar.gz
+        run: |
+          echo '${{ secrets.GNUPG_KEY }}' | gpg --batch --import
+          # Sadly a few lines in the private key match a few lines in the public key,
+          # As a result just --export --armor gives us a few lines replaced with ***
+          # making it useless for importing the signing key. Instead, we dump it as
+          # non-armored and hex-encode it so that its printable.
+          echo "PGP Signing key, in raw PGP format in hex. Import with cat ... | xxd -r -p - | gpg --import"
+          gpg --export | xxd -p
+          echo '${{ secrets.GNUPG_PASSPHRASE }}' | gpg --batch --yes --pinentry-mode loopback --passphrase-fd 0 --armor --detach-sign cinny-${{ steps.vars.outputs.tag }}.tar.gz
+      - name: Upload tagged release
+        uses: softprops/action-gh-release@1e07f4398721186383de40550babbdf2b84acfc5
+        with:
+          files: |
+            cinny-${{ steps.vars.outputs.tag }}.tar.gz
+            cinny-${{ steps.vars.outputs.tag }}.tar.gz.asc
+
   deploy-to-netlify:
     name: 'Deploy to Netlify'
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3.0.2
@@ -20,28 +54,12 @@ jobs:
           BUILD_DIRECTORY: "dist"
           NETLIFY_DEPLOY_MESSAGE: "Prod deploy v${{ github.ref }}"
           NETLIFY_DEPLOY_TO_PROD: true
-      - name: Get version from tag
-        id: vars
-        run: echo ::set-output name=tag::${GITHUB_REF#refs/*/}
-      - name: Create tar.gz
-        run: tar -czvf cinny-${{ steps.vars.outputs.tag }}.tar.gz dist
-      - name: Sign tar.gz
-        uses: actionhippie/gpgsign@4e28208b142cae93e1582401dcda1cf79e4f72c0
-        with:
-          private_key: ${{ secrets.GNUPG_KEY }}
-          passphrase: ${{ secrets.GNUPG_PASSPHRASE }}
-          detach_sign: true
-          files: cinny-${{ steps.vars.outputs.tag }}.tar.gz
-      - name: Upload tagged release
-        uses: softprops/action-gh-release@1e07f4398721186383de40550babbdf2b84acfc5
-        with:
-          files: |
-            cinny-${{ steps.vars.outputs.tag }}.tar.gz
-            cinny-${{ steps.vars.outputs.tag }}.tar.gz.asc
 
   push_to_dockerhub:
     name: Push Docker image to Docker Hub
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3.0.2