🚀(scalingo) custom logo override

(scalingo) custom logo override

bin/buildpack_postfrontend.sh

@@ -9,6 +9,40 @@ echo "-----> Running post-frontend script"
 mkdir -p build/
 mv src/frontend/dist build/frontend-out
 
+ASSETS_DIR=build/frontend-out/assets
+if [ -n "$CUSTOM_LOGO_URL" ]; then
+    # Ensure https
+    [[ ! "$CUSTOM_LOGO_URL" =~ ^https:// ]] && echo "[custom-logo] ERROR: URL must use HTTPS" >&2 && exit 1
+
+    # Prevent SSRF
+    HOSTNAME=$(echo "$CUSTOM_LOGO_URL" | sed -E 's|^https://([^/:]+).*|\1|')
+    [[ "$HOSTNAME" =~ ^(localhost|127\.|10\.|172\.(1[6-9]|2[0-9]|3[01])\.|192\.168\.|0\.0\.0\.0|\[::1\]) ]] && echo "[custom-logo] ERROR: SSRF blocked: $HOSTNAME" >&2 && exit 1
+
+    LOGO_FILE="${ASSETS_DIR}/logo.svg"
+    TMP_FILE=$(mktemp "${LOGO_FILE}.XXXXXX.tmp")
+
+    # Actual download
+    echo "[custom-logo] INFO: Downloading custom logo from: $CUSTOM_LOGO_URL"
+    curl -fsSL --tlsv1.2 -o "$TMP_FILE" "$CUSTOM_LOGO_URL"
+
+    # Validate filesize
+    FILESIZE=$(stat -c%s "$TMP_FILE" 2>/dev/null || stat -f%z "$TMP_FILE")
+    [[ "$FILESIZE" -eq 0 ]] && echo "[custom-logo] ERROR: empty file" >&2 && exit 1
+    [[ "$FILESIZE" -gt 5242880 ]] && echo "[custom-logo] ERROR: file too large (${FILESIZE}B > 5MB)" >&2 && exit 1
+
+    # Validate file type
+    IS_SVG=false
+
+    HEADER=$(head -c 100 "$TMP_FILE" | tr -d '\0' | tr '[:upper:]' '[:lower:]')
+    [[ "$HEADER" =~ ^.*"<svg".*$ ]] && IS_SVG=true
+    [[ "$HEADER" =~ ^.*"<?xml".*"<svg".*$ ]] && IS_SVG=true
+
+    [[ "$IS_SVG" == false ]] && echo "[custom-logo] ERROR: not a valid SVG file" >&2 && exit 1
+
+    mv -f "$TMP_FILE" "$LOGO_FILE"
+    echo "[custom-logo] INFO: Custom logo downloaded successfuly"
+fi
+
 mv src/backend/* ./
 mv deploy/paas/* ./