Added pinentry (now needed to generate gnupg2 keys)

There are different versions (qt/gtk and console)
Shall we strive for a solution working out of the box (see comments in gnupg2)
I think a gui pinentry is more suitable because it also works invoked from guil email clients

svn path=/nixpkgs/trunk/; revision=11695

pkgs/tools/misc/pinentry/default.nix

@@ -0,0 +1,17 @@
+args:
+args.stdenv.mkDerivation {
+  name = "pinentry-0.7.2";
+
+  src = args.fetchurl {
+    url = http://gentoo.chem.wisc.edu/gentoo/distfiles/pinentry-0.7.2.tar.gz;
+    sha256 = "0s6n5n4bxg95rmwa3mw3r49dabf8yh6fkpfi8mbl7i85dgpibnzv";
+  };
+
+  buildInputs =(with args; [glib pkgconfig x11 gtk]);
+
+  meta = { 
+      description = "input interface for passwords needed by  gnupg";
+      homepage = "don't know, gentoo lists http://www.gnupg.org/aegypten/";
+      license = "GPL2";
+  };
+}

pkgs/tools/security/gnupg2/default.nix

@@ -1,4 +1,8 @@
-args: with args;
+# remmeber to
+# echo "pinentry-program `which pinentry-gtk-2`" >> ~/.gnupg/gpg-agent.conf
+# and install pinentry as well
+
+args: with args
 stdenv.mkDerivation {
   name = "gnupg-2.0.8";
   src = fetchurl {