Processing and AES.

Programming Questions

runnerway

in Programming Questions • 1 year ago

http://java.sun.com/developer/technicalArticles/Security/AES/AES_v1.html

I'm trying to implement this code.

This is the sketch:

import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
void setup() {
String message="This is just an example";
// Get the KeyGenerator
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128); // 192 and 256 bits may not be available
// Generate the secret key specs.
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
// Instantiate the cipher
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted =
cipher.doFinal((args.length == 0 ?
"This is just an example" : args[0]).getBytes());
println("encrypted string: " + encrypted);
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] original =
cipher.doFinal(encrypted);
String originalString = new String(original);
println("Original string: " +
originalString + " " + original);
}
void draw() {
}

But when i try to start:

NoSuchAlgorithmException

At line 14..

Mmm..Why?..It has to be included in standard Java.

Replies(3)

PhiLho

You read and report half of the error message...
It is Unhandled exception type NoSuchAlgorithmException.
It is a compilation error, not a runtime error.
This means you have to wrap the faulty line with a try / catch structure. Search for checked exceptions in java for an explanation why it is necessary...

runnerway

Re: Processing and AES.

1 year ago

I know. But i was asking why if i try this code with a Java IDE all works but i try this code in processing i have this error..Where is the error?

PhiLho

Re: Processing and AES.

1 year ago

From the page you link to:

public static void main(String[] args) throws Exception {

The throws Exception is an alternative to try / catch: instead of handling the error, it tells it will thrown an exception, and it is the task of the code calling this function to catch it.
Except that's Java which call main(), so it is a way to evacuate the problem. Of course, if the exception is thrown, the program just crashes and burns...

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