anchor.diff:  
   RUN \
       cd /tmp/build/nginx && \
  -    # Verify signature
  -    curl -SLO https://nginx.org/download/nginx-${NGINX_VERSION}.tar.gz.asc && \
  +
  +    # GPG keys from the main maintainers of Nginx
  +    # Source https://nginx.org/en/pgp_keys.html
       curl -SLO https://nginx.org/keys/nginx_signing.key && \
       gpg --import nginx_signing.key && \
       curl -SLO https://nginx.org/keys/aalexeev.key && \
  
positive.code:     # Download PHP
      curl -SLo php-${PHP_VERSION}.tar.gz http://ch1.php.net/get/php-${PHP_VERSION}.tar.gz/from/this/mirror
  
  # RUN \
      # TODO SIG VERIFICATION!!!
  
  RUN \
      cd /tmp/build/php && \
  
negative.code:     gpg --import maxim.key && \
      curl -SLO https://nginx.org/keys/sb.key && \
      gpg --import sb.key && \
  
      # Verify signature
      curl -SLO https://nginx.org/download/nginx-${NGINX_VERSION}.tar.gz.asc && \
      gpg nginx-${NGINX_VERSION}.tar.gz.asc
  
  RUN \
  