JRUBY-4326: Confusing (and late) OpenSSL error message

Notice the JCE restriction to users when InvalidKeyException is raised.
This exception also thrown when IV length or key length is wrong but
those length should be checked before initialization.

Author: Hiroshi Nakamura

src/java/org/jruby/ext/openssl/Cipher.java

@@ -647,6 +647,8 @@ private void doInitialize() {
             } else {
                 this.ciph.init(encryptMode ? javax.crypto.Cipher.ENCRYPT_MODE : javax.crypto.Cipher.DECRYPT_MODE, new SimpleSecretKey(realName.split("/")[0], this.key));
             }
+        } catch (java.security.InvalidKeyException ike) {
+            throw newCipherError(getRuntime(), ike.getMessage() + ": possibly you need to install Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files for your JRE");
         } catch (Exception e) {
             if (DEBUG) {
                 e.printStackTrace();