Nigel Shrin

Hi John,
many thanks for the links and example code, very much appreciated, I'll work through these examples at the weekend.

Cheers!
Nigel

Yes, I posted it on stackexchange yesterday. I was unaware of the term cross posting, and the policy - apologies if that has offended anyone.
I haven't had a reply from either site. Are you able to help?

Hi, I am trying to connect a pojo holding all the required xy coordinates, to a javafx scene graph, and cannot work out how to do this. It is a simple Javafx scene graph created with scenebuilder; a circle and three lines, and an exit button.

How do I connect the pojo holding with coords to javafx scene graph?

So far I have, all within a javafx enabled project in e(fx)clipse:
1) "classA": GeometryCalculator class, includes a member class object GeometryResultsObj
The output of classA is one instance of classB. This is in a for loop to run from 1-360 degrees, overwriting classB for each change.
2) "classB": GeometryResultsObj stores, the circle diameter, circle xy centre, 3 lines xy start & end coords
3) "classC": GeometryGraphic.java contains main() with launch() and start()
4) "classD": GeometryGraphic.fxml with a static circle and three lines (waiting to be animated)
5) "classE": GeometryGraphicController java class, contains initialize() and initData(classB coords).

ClassA is tested and calculates ok.
ClassB is correctly populated when classA is run.
ClassC when run, displays the scenegraph with circle & lines in their original positions, with no errors.

I've tried creating an initData method on the controller class which does a set on each fxml object with a get on the relevant pojo field. If I run the controller there is no classB of coordinates to read, but it runs ok, and displays the graphic with circle and lines in their initial positions.

AIM:
To run the series of outputs to the scenegraph for 1-360 events, with a next button, so they can be visually checked for incorrect logic in classA. It would also be great to add a play button, with slow & fast slider to view a continously animated output.

The structure probably isn't quite right, as the driver is the ClassA. Driving from ClassC finds no ClassB with coordinate data. ClassA could be changed quite easily to create a result object per iteration (1-360) and add these to a collection.

Can you please advise how to link the graph to the coordinates, and how this should be restructured to enable this.
The nearest I can think of is calling the method in ClassA at the beginning of the controller classE's initData function?

I haven't included code as it would be a lot to post, even a cut down version. Advice on the correct approach & structure would be very much appreciated.

Thank you!

Hi Richard,
I don't mind in the slightest, and I am very grateful for the time you have taken to explain some principles of encryption to me. I read your comments yesterday evening and have ordered your recommended book. I think Java is a great language, and would very much like to improve the quality of my coding.

Although I knew the line of the error, I didn't know how to fix it! I am not familiar with many of the terms & concepts at this point; PKCS1, modulus length, padding etc. I thought I was only using AES256 and not RSA as well. I did O-level maths, but did not study maths further. So please forgive my ignorance. My next attempt may not be until next weekend - the book should have arrived by then.

Thank you for taking the time & effort to further my understanding.

Thanks Richard,

here's the enum:

package encryption; import java.io.Serializable; public enum EnumInData2Store implements Serializable{ YES, NO; }

In the previous to last example I had problems trying to store the key, so I read some more and found keystore.
The current example is to a large extent based on the code from the javadoc, I use Eclipse and that forced me to put so many catch clauses in.
http://docs.oracle.com/javase/7/docs/api/java/security/KeyStore.html#getInstance(java.lang.String)

I'll try and modify it tonight to just use a string to encrypt.

Can you see where the exception is coming from?

Thanks again for your time,

I just noticed that the alias was different on line 120, so I made it the same, but this made no difference to the error message:

line 120 (was: "privateKeyAlias") now reads:
myKeyStore.getEntry(KEYSTORE_ALIAS, protectionParameter);

thank you!

Hi,
I have attempted to implement KeyStore but currently get an uninitialised keystore error.
The map of objects to encrypt then serialise is created, but no attempt has been made to do this yet.
The error has occurred from trying to create a KeyStore then retrieve the SecretKey for it.

Full error from line 86:

java.security.KeyStoreException: Uninitialized keystore at java.security.KeyStore.setEntry(KeyStore.java:1324) at encryption.EncryptSealSerializeMethods.createSaveKeyStore(EncryptSealSerializeMethods.java:86) at encryption.EncryptSealSerializeMethods.main(EncryptSealSerializeMethods.java:50)

Full code:

import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.ObjectInputStream.GetField; import java.io.ObjectOutputStream; import java.io.Serializable; import java.security.InvalidKeyException; import java.security.Key; import java.security.KeyStore; import java.security.KeyStoreException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.security.PrivateKey; import java.security.Security; import java.security.UnrecoverableEntryException; import java.security.cert.CertificateException; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; import java.util.Set; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.KeyGenerator; import javax.crypto.NoSuchPaddingException; import javax.crypto.SealedObject; import javax.crypto.SecretKey; public class EncryptSealSerializeMethods { private static final String KEYSTORE_PASSWORD = "myPassword"; private static final String KEYSTORE_ALIAS = "myStore"; private KeyStore myKeyStore; private KeyStore.SecretKeyEntry secretKeyEntry; private KeyStore.ProtectionParameter protectionParameter; private KeyGenerator keyGen; private SecretKey secretKey, mySecretKey; private PrivateKey myPrivateKey; public static void main(String[] args) { EncryptSealSerializeMethods ess = new EncryptSealSerializeMethods(); ess.createMapOfData2Store(); ess.createSaveKeyStore(); // ess.getKeyFromStore(); } public void createMapOfData2Store(){ LinkedHashMap<Integer, Data2Store> lhm = new LinkedHashMap<Integer, Data2Store>(); int i = 10; Data2Store ds[] = new Data2Store[i]; for(i=1; i<10; i++){ ds[i] = new Data2Store(); ds[i].setA(100+i); ds[i].setEnum1(EnumInData2Store.YES); lhm.put(i, ds[i]); } // show_map(lhm); } public static void show_map (LinkedHashMap<Integer, Data2Store> lhm) { for (Map.Entry<Integer, Data2Store> e : lhm.entrySet()) { System.out.println(e.getKey() + "\t" + e.getValue().getA() + "\t" + e.getValue().getEnum1()); } } public void createSaveKeyStore(){ try { myKeyStore = KeyStore.getInstance("JCEKS"); // 'load' the store keyGen = KeyGenerator.getInstance("AES"); keyGen.init(256); mySecretKey = keyGen.generateKey(); protectionParameter = new KeyStore.PasswordProtection(KEYSTORE_PASSWORD.toCharArray()); // get pw secretKeyEntry = new KeyStore.SecretKeyEntry(mySecretKey); myKeyStore.setEntry(KEYSTORE_ALIAS, secretKeyEntry, protectionParameter); // ERROR HERE: java.security.KeyStoreException: Uninitialized keystore FileInputStream fis = null; try { fis = new FileInputStream("C:/Users/1. Nigel Shrin/Desktop/ks"); // if null, creates empty KeyStore myKeyStore.load(fis, KEYSTORE_PASSWORD.toCharArray()); } catch (CertificateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } } } catch (KeyStoreException e) { e.printStackTrace(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } } public PrivateKey getKeyFromStore(){ KeyStore.PrivateKeyEntry pkEntry; try { pkEntry = (KeyStore.PrivateKeyEntry) myKeyStore.getEntry("privateKeyAlias", protectionParameter); myPrivateKey = pkEntry.getPrivateKey(); // retrieved key } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (UnrecoverableEntryException e) { e.printStackTrace(); } catch (KeyStoreException e) { e.printStackTrace(); } closeKeyStore(); System.out.println("myPrivateKey: " + myPrivateKey.toString()); return myPrivateKey; } public void closeKeyStore(){ FileOutputStream fos = null; try { fos = new java.io.FileOutputStream("C:/Users/1. Nigel Shrin/Desktop/ks"); myKeyStore.store(fos, KEYSTORE_PASSWORD.toCharArray()); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (KeyStoreException e) { e.printStackTrace(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (CertificateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { if (fos != null) { try { fos.close(); } catch (IOException e) { e.printStackTrace(); } } } } }

object in map:

package encryption; import java.io.Serializable; public class Data2Store implements Serializable { private int a = 100; private EnumInData2Store enum1 = EnumInData2Store.YES; // getters & setters public int getA() { return a; } public void setA(int a) { this.a = a; } public EnumInData2Store getEnum1() { return enum1; } public void setEnum1(EnumInData2Store enum1) { this.enum1 = enum1; } }

thank you!

Thanks Richard,
I'll do that, it'll be tomorrow now, I've been playing with this most of today,
Kind regards,

Hi Richard

1) I don't understand why "The getSkey() call on line 3, is a setter," . Surely it is a getter .
2) I don't understand why in line 3 of getStoreKey() you need to generate a key.
3) I don't understand "skUnsealed.equals((SecretKey)sealed2.getObject(dciTemp)); " . Since 'skUnsealed' is generated by a keyGen.generateKey() it probably returns a new random key so the chances of this new key being equal to any other key is just about zero.
4) I thought you were trying to place a collection in the sealed object and not a key.

point 1 - my typo, it is a getter, apologies
point 2 - I didn't want another secret key, just a way to return the result (extracted key), looking at it again, perhaps I could have done this on line 9, at the end of the try block:
return (SecretKey)sealed2.getObject(dciTemp);
point 3 - explained by answer to point 2
point 4 - this is a test to return a saved SecretKey that is in a SealedObject and serialized so it can be reused, when I have this working, so I am working towards the collection.

I could work on a SSCCE if the above is still not clear enough.

thanks again for your help,

NPE retrieving SecretKey from sealed object

Hi,

I am having difficult tracing this error, the exact error is:

getSkey(): javax.crypto.spec.SecretKeySpec@1234a Exception in thread "main" java.lang.NullPointerException at io_streams.EncryptSealedObject.getStoreKey(EncryptSealedObject.java:151) at io_streams.EncryptSealedObject.main(EncryptSealedObject.java:45)

line 45 is a test call to the routine below from main():
public static void main(String[] args) {

EncryptSealedObject eso = new EncryptSealedObject(); eso.getStoreKey();

Method:

public SecretKey getStoreKey(){ SecretKey skUnsealed = keyGen.generateKey(); System.out.println("getSkey(): " + getSkey()); try { Cipher dciTemp = Cipher.getInstance("AES"); dciTemp.init(Cipher.DECRYPT_MODE, getSkey()); skUnsealed.equals((SecretKey)sealed2.getObject(dciTemp)); } catch (NoSuchAlgorithmException e) { System.out.println("No Such Algorithm:" + e.getMessage()); } catch (NoSuchPaddingException e) { System.out.println("No Such Padding:" + e.getMessage()); } catch (InvalidKeyException e) { System.out.println("Invalid Key:" + e.getMessage()); } catch (BadPaddingException e) { System.out.println("Bad Padding:" + e.getMessage()); } catch (IllegalBlockSizeException e) { System.out.println("Illegal Block:" + e.getMessage()); } catch (ClassNotFoundException e) { System.out.println("Class Not Found:" + e.getMessage()); } catch (IOException e) { System.out.println("I/O Error:" + e.getMessage()); } return skUnsealed; }

I am pretty sure the error is in lines 3 or 9. The reason I created an object in line 3 was to have a return variable.
The getSkey() call on line 3, is a setter, to return the static class member, and this call works in itself.

Many thanks

thanks Richard, much appreciated!

Hi,
am I correct in saying the SecretKey is a system generated password in effect, so it must be stored for use in the decipher object at a later date?

keyGen = KeyGenerator.getInstance("AES"); keyGen.init(256); SecretKey skey = keyGen.generateKey(); ecipher = Cipher.getInstance("AES"); dcipher = Cipher.getInstance("AES"); ecipher.init(Cipher.ENCRYPT_MODE, skey); dcipher.init(Cipher.DECRYPT_MODE, skey);

thank you

will do; a learning curve at the moment!
thanks for your help

Thanks Richard, key is an instance of KeyGenerator already, I've renamed it to be keyGen to make that clearer.

keyGen = KeyGenerator.getInstance("AES"); // System.out.println(key.getAlgorithm()); // AES keyGen.init(256); SecretKey skey = keyGen.generateKey(); // returns a String ecipher = Cipher.getInstance("AES"); dcipher = Cipher.getInstance("AES"); System.out.println("aes block size: " + ecipher.getBlockSize()); // 16 System.out.println("max allowed: " + ecipher.getMaxAllowedKeyLength("AES")); // max allowed: 2147483647 // initialize the ciphers with the given key ecipher.init(Cipher.ENCRYPT_MODE, skey); dcipher.init(Cipher.DECRYPT_MODE, skey);

the SecretKey line is new, and this is now accepted in the cipher initialisation lines (13 & 14).
It does looks more promising, not run yet.

thanks!

Hi Ulf,

My key id was an instance of SecretKey, when I changed this to be an instance of KeyGenerator then I was able to split line 31 without errors.
However the cipher lines 15 & 16, no longer accept the key, it expects Key and not KeyGenerator.

// generate SecretKey using AES algorithm key = KeyGenerator.getInstance("AES"); key.generateKey(); // System.out.println(key.getAlgorithm()); // AES key.init(256); ecipher = Cipher.getInstance("AES"); dcipher = Cipher.getInstance("AES"); System.out.println("aes block size: " + ecipher.getBlockSize()); // 16 System.out.println("max allowed: " + ecipher.getMaxAllowedKeyLength("AES")); // max allowed: 2147483647 // initialize the ciphers with the given key ecipher.init(Cipher.ENCRYPT_MODE, key); // ERROR expects KeyGenerator dcipher.init(Cipher.DECRYPT_MODE, key); // ERROR expects KeyGenerator

not sure of the relationship from KeyGenerator back to Key to initialize the Cipher objects?

thanks again for your help