java aes 256 java.security.InvalidKeyException: Illegal key size after installation the policy

Question

i have a problem with the encrypt of the bytes with an AES 256 key. I already installed the policy. Here's what I've done:

download the file: http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html
I moved the files local_policy and US_export_policy to the directory /Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home/jre/lib/security
i restart the mac

But still I get an error message with the following code:

KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
keyGenerator.init(256);
SecretKey secretKey = keyGenerator.generateKey();
Cipher decryption = Cipher.getInstance("AES/CBC/PKCS5PADDING");
decryption.init(Cipher.DECRYPT_MODE, secretKey, 
new IvParameterSpec(secretKey.getEncoded())); // <-- Illegal key size

My Java version:

java version "1.7.0_40"
Java(TM) SE Runtime Environment (build 1.7.0_40-b43)
Java HotSpot(TM) 64-Bit Server VM (build 24.0-b56, mixed mode)

What i have to do, to use the 256 AES encryption?

Code should be properly formatted. Why did you roll back my edit that repaired your format? — bmargulies, Dec 27 '13 at 14:33
Please don't use the key as IV - you will open up to a chosen-ciphertext attack which recovers the key. If you must use a fixed IV, 0 would be safer. — Ebbe M. Pedersen, Dec 27 '13 at 16:28
Thanks, but why should I use no padding? If the key length is not known, then it would be safer, is it? — user2279172, Dec 28 '13 at 15:40

score 4 · Accepted Answer · answered Dec 27 '13 at 15:47

4

Policy files should resolve the issue. Check the path environment variable to confirm that you are using the same jre which has policy files.

answered Dec 27 '13 at 15:47

Saran Makam

126
7

i checked my $JAVA_HOME (result: "/Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home") or i started my java program with following command: " / Library/Java/JavaVirtualMachines/jdk1.7.0_40.jdk/Contents/Home/bin/java-jar sec_test.jar", but it doesn't work. After that i copied the policy file in the other directory ("/Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home/bin"), i was able to start the program. Ok it works, but why? I checked the path to ire and i have started the program explicitly with this JRE 1.7.0_40. Are there any other settings of JRE? – user2279172 Dec 28 '13 at 14:13
Check the $PATH environment variable, you will find which java is configured for your environement – Saran Makam Dec 31 '13 at 11:07

score 3 · Answer 2 · answered Feb 28 '14 at 02:50

3

IMPORTANT: you have know you jre location. eg: in my compute have C:\Java\jre7\lib\security and C:\Java\jdk1.7.0_02\jre\lib\security, but eclipse show the jre is C:\Java\jre7\lib\security,so you must copy two file into here.

answered Feb 28 '14 at 02:50

hnrain

3,041
1
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score 1 · Answer 3 · answered Jan 22 '15 at 14:55

1

What I did downloaded policy file from this location http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html paste in location jre/lib/security/ and it workes....

answered Jan 22 '15 at 14:55

Lokesh Tiwari

10,496
3
36
45

java aes 256 java.security.InvalidKeyException: Illegal key size after installation the policy

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