Package org.openmuc.jdlms

Class SecurityUtils

java.lang.Object

org.openmuc.jdlms.SecurityUtils

public class SecurityUtils
extends java.lang.Object

A static utility class that provides security functions.

This class is useful if you may want to change the security setup of the remote meter.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SecurityUtils.KeyId

Method Summary

Modifier and Type	Method	Description
static byte[]	cipherWithAes128(byte[] masterKey, byte[] iv, byte[] bytesToCipher)	Encrypts a byte array with a master key with the algorithm AES in mode CBC and no padding.
static byte[]	generateAES128Key()	Generates a random AES 128 key
static byte[]	generateAES256Key()	Generates a random AES 256 key
static MethodParameter	keyChangeMethodParamFor(byte[] masterKey, byte[] newKey, SecurityUtils.KeyId keyId)	Returns the method parameter for updating a single key of a DLMS server.
static MethodParameter	securityActivateMethodParamFor(SecuritySuite.SecurityPolicy securityPolicy)	Sets the security policy method parameter
static byte[]	unwrapAesRFC3394Key(byte[] kek, byte[] wrappedKey)	This function unwraps a wrapped key with the kek (key encryption key)
static byte[]	wrapAesRFC3394Key(byte[] kek, byte[] key)	This function wraps a key with a kek (key encryption key)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

keyChangeMethodParamFor

public static MethodParameter keyChangeMethodParamFor(byte[] masterKey,
                                                      byte[] newKey,
                                                      SecurityUtils.KeyId keyId)

Returns the method parameter for updating a single key of a DLMS server.

Parameters:

masterKey - the master key, also known as KEK

newKey - the new key to update to the DLMS server

keyId - the type of key to update

Returns:

return MethodParameter for global key transfer

securityActivateMethodParamFor

public static MethodParameter securityActivateMethodParamFor(SecuritySuite.SecurityPolicy securityPolicy)

Sets the security policy method parameter

Parameters:

securityPolicy - the security policy to set for

Returns:

return MethodParameter for security policy

cipherWithAes128

public static byte[] cipherWithAes128(byte[] masterKey,
                                      byte[] iv,
                                      byte[] bytesToCipher)
                               throws java.security.GeneralSecurityException

Encrypts a byte array with a master key with the algorithm AES in mode CBC and no padding.

Parameters:

masterKey - the master key for encryption the bytesToCypher.

iv - the initialization vector.

bytesToCipher - the bytes to cipher.

Returns:

the bytesToCipher encrypted

Throws:

java.security.GeneralSecurityException - caused by Cipher.doFinal(byte[]) or Cipher.init(int, Key)

wrapAesRFC3394Key

public static byte[] wrapAesRFC3394Key(byte[] kek,
                                       byte[] key)

This function wraps a key with a kek (key encryption key)

Parameters:

kek - the key encryption key for wrapping the key

key - the key to wrap

Returns:

returns a with kek wrapped key

unwrapAesRFC3394Key

public static byte[] unwrapAesRFC3394Key(byte[] kek,
                                         byte[] wrappedKey)
                                  throws org.bouncycastle.crypto.InvalidCipherTextException

This function unwraps a wrapped key with the kek (key encryption key)

Parameters:

kek - the key encryption key for unwrapping the wrapped key

wrappedKey - the wrapped key to unwrap

Returns:

returns a unwrapped key

Throws:

org.bouncycastle.crypto.InvalidCipherTextException - will thrown if something unexpected is in the wrappedKey

generateAES128Key

public static byte[] generateAES128Key()

Generates a random AES 128 key

Returns:

returns a random AES 128 key

generateAES256Key

public static byte[] generateAES256Key()

Generates a random AES 256 key

Returns:

returns a random AES 128 key