software.common
Class SecurityUtil

java.lang.Object
  software.common.SecurityUtil

public class SecurityUtil
extends java.lang.Object

Field Summary

static javax.crypto.Cipher	cipherNoPaddingNoKey
static javax.crypto.Cipher	cipherPkcs5Padding

Constructor Summary

SecurityUtil()

Method Summary

static void	checkDrowCommitment(byte[] s1, int d1, byte[] d2, java.lang.String c1, byte partitionId, byte dNo, java.lang.String did, byte[] c)
static void	checkProwCommitment(byte[] s1, byte[] p1, java.lang.String c1, java.lang.String pid, byte[] c)
static byte[]	getCommitment(javax.crypto.spec.SecretKeySpec skm, byte[] c, byte[] m) Given a message m, a secretKey skm and a public constant it returnes the commitment to the message m.
static java.lang.String	toPEM(java.security.cert.X509Certificate cert) Converts an X509 certificate from BER to PEM
static javax.crypto.spec.SecretKeySpec	tripleAES(javax.crypto.spec.SecretKeySpec mk1, javax.crypto.spec.SecretKeySpec mk2, byte[] c, byte[] message) generates a pseuso random AES 128bit key from "message".

Methods inherited from class java.lang.Object

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

Field Detail

cipherNoPaddingNoKey

public static javax.crypto.Cipher cipherNoPaddingNoKey

cipherPkcs5Padding

public static javax.crypto.Cipher cipherPkcs5Padding

Constructor Detail

SecurityUtil

public SecurityUtil()

Method Detail

tripleAES

public static javax.crypto.spec.SecretKeySpec tripleAES(javax.crypto.spec.SecretKeySpec mk1,
                                                        javax.crypto.spec.SecretKeySpec mk2,
                                                        byte[] c,
                                                        byte[] message)
                                                 throws java.lang.Exception

generates a pseuso random AES 128bit key from "message". The formula used to generate the key is: Km = Dmk1 (C XOR Emk2 (C XOR Emk1(message))), where D standes for decrypt and E for Encrypt. Emk1 means Encrypt with the key "mk1" (master key 1). The encryption scheme used is AES/ECB/NoPadding the following restrictions apply: message.length = 16 c.length = 16 rawKey1.length = 16 rawKey2.length = 16 Otherwise the method will throw an Exception

Parameters:

mk1 - an AES 128 bit key

mk2 - an AES 128 bit key

c - a constant. c.length = 16;

message - 16byte message

Returns:

an AES 128bit key

Throws:

java.lang.Exception - - no exceptions are caugth

getCommitment

public static byte[] getCommitment(javax.crypto.spec.SecretKeySpec skm,
                                   byte[] c,
                                   byte[] m)
                            throws java.lang.Exception

Given a message m, a secretKey skm and a public constant it returnes the commitment to the message m. The commitment is computed as follows: sak=Encrypt C with skm h1 = SHA256(m, sak). h2 = SHA256(m, Encrypt h1 with sak) the commitment is h1h2 (h1 concatenated with h2) where E stands for Encrypt. The encryption scheme used is AES/ECB/NoPadding

Parameters:

skm - - the salt used in the commitment

c - - the public constant

m - - the message to be commited to

Returns:

- a commitment to m

Throws:

java.lang.Exception

checkProwCommitment

public static void checkProwCommitment(byte[] s1,
                                       byte[] p1,
                                       java.lang.String c1,
                                       java.lang.String pid,
                                       byte[] c)
                                throws org.xml.sax.SAXException

Parameters:

s1 - - salt

p1 - - message

c1 - - commitment

pid - - p id

c - - public constant

Throws:

org.xml.sax.SAXException - if the commitment does not checks. The commitment is constructed using SecurityUtil.getCommitment

checkDrowCommitment

public static void checkDrowCommitment(byte[] s1,
                                       int d1,
                                       byte[] d2,
                                       java.lang.String c1,
                                       byte partitionId,
                                       byte dNo,
                                       java.lang.String did,
                                       byte[] c)
                                throws org.xml.sax.SAXException

Parameters:

s1 - - salt

d1 - - d1 (pointer to P or R)

d2 - - transformation

c1 - - commitment

partitionId -

dNo -

did -

c - - public constant

Throws:

org.xml.sax.SAXException - if the commitment does not checks. The commitment is constructed using SecurityUtil.getCommitment

toPEM

public static java.lang.String toPEM(java.security.cert.X509Certificate cert)
                              throws java.security.cert.CertificateEncodingException

Converts an X509 certificate from BER to PEM

Parameters:

cert - - an X509 Certificate

Returns:

- a String with the PEM format of the certificate(Base64, 65 characters per line)

Throws:

java.security.cert.CertificateEncodingException