Merge pull request nginx-proxy#913 from panteparak/DH-Param-Generator-Option

Add DH param generator option

Author: jwilder

README.md

@@ -181,8 +181,12 @@ Finally, start your containers with `VIRTUAL_HOST` environment variables.
     $ docker run -e VIRTUAL_HOST=foo.bar.com  ...
 ### SSL Support using letsencrypt
 
-[letsencrypt-nginx-proxy-companion](https://github.com/JrCs/docker-letsencrypt-nginx-proxy-companion) is a lightweight companion container for the nginx-proxy. It allow the creation/renewal of Let's Encrypt certificates automatically. 
+[letsencrypt-nginx-proxy-companion](https://github.com/JrCs/docker-letsencrypt-nginx-proxy-companion) is a lightweight companion container for the nginx-proxy. It allow the creation/renewal of Let's Encrypt certificates automatically.
 
+Set `DHPARAM_GENERATION` environment variable to `false` to disabled Diffie-Hellman parameters completely. This will also ignore auto-generation made by `nginx-proxy`.
+The default value is `true`
+
+     $ docker run -e DHPARAM_GENERATION=false ....
 ### SSL Support
 
 SSL is supported using single host, wildcard and SNI certificates using naming conventions for
@@ -214,7 +218,7 @@ at startup.  Since it can take minutes to generate a new `dhparam.pem`, it is do
 background.  Once generation is complete, the `dhparam.pem` is saved on a persistent volume and nginx
 is reloaded.  This generation process only occurs the first time you start `nginx-proxy`.
 
-> COMPATIBILITY WARNING: The default generated `dhparam.pem` key is 2048 bits for A+ security.  Some 
+> COMPATIBILITY WARNING: The default generated `dhparam.pem` key is 2048 bits for A+ security.  Some
 > older clients (like Java 6 and 7) do not support DH keys with over 1024 bits.  In order to support these
 > clients, you must either provide your own `dhparam.pem`, or tell `nginx-proxy` to generate a 1024-bit
 > key on startup by passing `-e DHPARAM_BITS=1024`.
@@ -282,12 +286,12 @@ a 500.
 
 To serve traffic in both SSL and non-SSL modes without redirecting to SSL, you can include the
 environment variable `HTTPS_METHOD=noredirect` (the default is `HTTPS_METHOD=redirect`).  You can also
-disable the non-SSL site entirely with `HTTPS_METHOD=nohttp`, or disable the HTTPS site with 
-`HTTPS_METHOD=nohttps`. `HTTPS_METHOD` must be specified on each container for which you want to 
-override the default behavior.  If `HTTPS_METHOD=noredirect` is used, Strict Transport Security (HSTS) 
-is disabled to prevent HTTPS users from being redirected by the client.  If you cannot get to the HTTP 
-site after changing this setting, your browser has probably cached the HSTS policy and is automatically 
-redirecting you back to HTTPS.  You will need to clear your browser's HSTS cache or use an incognito 
+disable the non-SSL site entirely with `HTTPS_METHOD=nohttp`, or disable the HTTPS site with
+`HTTPS_METHOD=nohttps`. `HTTPS_METHOD` must be specified on each container for which you want to
+override the default behavior.  If `HTTPS_METHOD=noredirect` is used, Strict Transport Security (HSTS)
+is disabled to prevent HTTPS users from being redirected by the client.  If you cannot get to the HTTP
+site after changing this setting, your browser has probably cached the HSTS policy and is automatically
+redirecting you back to HTTPS.  You will need to clear your browser's HSTS cache or use an incognito
 window / different browser.
 
 By default, [HTTP Strict Transport Security (HSTS)](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security) 
@@ -410,7 +414,7 @@ Before submitting pull requests or issues, please check github to make sure an e
 To run tests, you need to prepare the docker image to test which must be tagged `jwilder/nginx-proxy:test`:
 
     docker build -t jwilder/nginx-proxy:test .  # build the Debian variant image
-    
+
 and call the [test/pytest.sh](test/pytest.sh) script.
 
 Then build the Alpine variant of the image:
@@ -423,7 +427,7 @@ and call the [test/pytest.sh](test/pytest.sh) script again.
 If your system has the `make` command, you can automate those tasks by calling:
 
     make test
-    
+
 
 You can learn more about how the test suite works and how to write new tests in the [test/README.md](test/README.md) file.
 

docker-entrypoint.sh

@@ -16,7 +16,8 @@ fi
 
 # Generate dhparam file if required
 # Note: if $DHPARAM_BITS is not defined, generate-dhparam.sh will use 2048 as a default
-/app/generate-dhparam.sh $DHPARAM_BITS
+# Note2: if $DHPARAM_GENERATION is set to false in environment variable, dh param generator will skip completely
+/app/generate-dhparam.sh $DHPARAM_BITS $DHPARAM_GENERATION
 
 # Compute the DNS resolvers for use in the templates - if the IP contains ":", it's IPv6 and must be enclosed in []
 export RESOLVERS=$(awk '$1 == "nameserver" {print ($2 ~ ":")? "["$2"]": $2}' ORS=' ' /etc/resolv.conf | sed 's/ *$//g')

generate-dhparam.sh

@@ -2,6 +2,7 @@
 
 # The first argument is the bit depth of the dhparam, or 2048 if unspecified
 DHPARAM_BITS=${1:-2048}
+GENERATE_DHPARAM=${2:-true}
 
 # If a dhparam file is not available, use the pre-generated one and generate a new one in the background.
 # Note that /etc/nginx/dhparam is a volume, so this dhparam will persist restarts.
@@ -25,6 +26,11 @@ if [[ -f $DHPARAM_FILE ]]; then
     fi
 fi
 
+if [[ $GENERATE_DHPARAM =~ ^[Ff][Aa][Ll][Ss][Ee]$ ]]; then
+    echo "Skipping Diffie-Hellman parameters generation and Ignoring pre-generated dhparam.pem"
+    exit 0
+fi
+
 cat >&2 <<-EOT
 WARNING: $DHPARAM_FILE was not found. A pre-generated dhparam.pem will be used for now while a new one
 is being generated in the background.  Once the new dhparam.pem is in place, nginx will be reloaded.