add openssl-with-rc4 package

pkgs/openssl-with-rc4.nix

@@ -0,0 +1,20 @@
+{ callPackage, openssl_1_1, path, stdenv }:
+
+# This package exists for testing.
+# ./result-bin/bin/openssl ciphers -v "ALL:@SECLEVEL=0" | grep RC4
+
+let
+
+  oldScript = openssl_1_1.configureScript;
+
+  edited = stdenv.mkDerivation {
+    name = "openssl-with-rc4";
+    src = path + "/pkgs/development/libraries/openssl";
+    installPhase = ''
+      sed -i 's|${oldScript}|${oldScript} enable-weak-ssl-ciphers|g' default.nix
+      cp -a . $out
+    '';
+  };
+
+in
+(callPackage edited { }).openssl_1_1