我目前正在尝试与 android 应用程序进行 diffie hellman 密钥交换。我得到了 diffie hellman 的代码，如下所示。
但是，我只是迷失了如何在服务器端和客户端实现它，以便它们相互通信。
我的代码如下所示
DH.java
公共类 DH {
static boolean isPrime(long n)
{
if (n%2 == 0)
{
return false;
}
for(int i = 3 ; i*i<=n;i+=2)
{
if(n%i==0)
return false;
}
return true;
}
public static void main(String [] args) throws Exception
{
Random randomGenerator = new Random();
long pValue = randomGenerator.nextInt(1000000);
long gValue = randomGenerator.nextInt(100000);
long correctPValue;
boolean checkPrime = isPrime(pValue);
System.out.println("the number generated is "+pValue);
System.out.println(checkPrime);
while(checkPrime == false)
{
long pValue2 = randomGenerator.nextInt(1000000);
boolean checkPrimeInLoop = isPrime(pValue2);
//System.out.println("value in loop is "+pValue2);
if(checkPrimeInLoop == true)
{
pValue=pValue2;
break;
}
}
long checkSP = (pValue*2)+1;
boolean checkSafePrime = isPrime(checkSP);
//System.out.println(checkSafePrime);
while(checkSafePrime==false)
{
long pValue3=randomGenerator.nextInt(1000000);
boolean checkPrimeInLoop = isPrime(pValue3);
long pValue5=(pValue3*2)+1;
//boolean checkSafePrimeInLoop = isPrime(pValue4);
boolean checkSafePrime2InLoop = isPrime(pValue5);
if(checkSafePrime2InLoop == true && checkPrimeInLoop == true)
{
pValue=pValue3;
break;
}
}
//System.out.println("the safe prime is"+pValue);//safe prime
while(gValue>pValue)
{
long gValue2=randomGenerator.nextInt(100000);
if(gValue2<pValue)
{
gValue=gValue2;
break;
}
}
long getDivisor = (pValue-1)/2;
BigInteger bi1,bi2,bi3,bi4,bi10,bi11,bi12,bi13;
bi1=BigInteger.valueOf(getDivisor);
bi2 = BigInteger.valueOf(pValue);
bi3 = BigInteger.valueOf(gValue);
bi4= bi3.modPow(bi1,bi2);
String getBi1 = bi1.toString();
String getBi2 = bi2.toString();
String getBi3 = bi3.toString();
String getBi4 = bi4.toString();
//bi10 = new BigInteger(getBi1,64); // divisor
//bi11 = new BigInteger(getBi2,64); // safe prime value
//bi12 = new BigInteger(getBi3,64); // generator value
//bi13 = new BigInteger(getBi4,64); // modular value
long calculatedValue = bi4.longValue();
while(calculatedValue == 1)
{
long gValue3=randomGenerator.nextInt(100000);
long getDivisorInLoop = (pValue-1)/2;
BigInteger bi5,bi6,bi7,bi8,bi14,bi15,bi16,bi17,bi18;
bi5=BigInteger.valueOf(getDivisorInLoop);
bi6 = BigInteger.valueOf(pValue);
bi7 = BigInteger.valueOf(gValue3);
bi8= bi7.modPow(bi5,bi6);
String getBi5 = bi5.toString();
String getBi6 = bi6.toString();
String getBi7 = bi7.toString();
String getBi8 = bi8.toString();
//bi14 = new BigInteger(getBi1,64); // divisor
//bi15 = new BigInteger(getBi2,64); // safe prime value
//bi16 = new BigInteger(getBi3,64); // generator value
//bi17 = new BigInteger(getBi4,64); // modular value
long calculatedValueInLoop = bi8.longValue();
System.out.println("the proof that it is a generator is "+calculatedValueInLoop);
if(calculatedValueInLoop!=1)
{
gValue=gValue3;
break;
}
}
BigInteger generatorValue,primeValue,biA,biB,skA,skB,sharedKeyA,sharedKeyB;
generatorValue = BigInteger.valueOf(gValue);
primeValue = BigInteger.valueOf(pValue);
long SecretKeyA=generateSKA();
long SecretKeyB=generateSKB();
skA = BigInteger.valueOf(SecretKeyA);
skB = BigInteger.valueOf(SecretKeyB);
biA=generatePkA(generatorValue,primeValue,SecretKeyA);
biB=generatePkB(generatorValue,primeValue,SecretKeyB);
sharedKeyA = calculateSharedKey(biB,skA,primeValue);
sharedKeyB = calculateSharedKey(biA,skB,primeValue);
System.out.println("the safe prime is"+primeValue);
System.out.println("the generator of the safe prime is "+generatorValue);
System.out.println("the public key of A is "+generatePkA(generatorValue,primeValue,SecretKeyA));
System.out.println("the public key of B is "+generatePkB(generatorValue,primeValue,SecretKeyB));
System.out.println("the shared key for A is"+calculateSharedKey(biB,skA,primeValue));
System.out.println("the shared key for B is"+calculateSharedKey(biA,skB,primeValue));
System.out.println("The secret key for A is"+generateSKA());
//createKey();
String getAValue=sharedKeyA.toString();
String getBValue=sharedKeyB.toString();
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update(getAValue.getBytes());
byte byteData[] = md.digest();
StringBuffer sb = new StringBuffer();
for(int i=0;i<byteData.length;i++)
{
sb.append(Integer.toString((byteData[i] & 0xff) + 0x100, 16).substring(1));
}
String getHexValue = sb.toString();
System.out.println("hex format in SHA-256 is "+getHexValue);
//createSpecificKey(biG,biP);
byte [] key = getAValue.getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-256");
key = sha.digest(key);
key = Arrays.copyOf(key, 16);
SecretKeySpec secretKeySpec = new SecretKeySpec(key,"AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
CipherInputStream cipt = new CipherInputStream(new FileInputStream(new File("C:\\Users\\Larry\\Desktop\\Java\\diffie hellman\\src\\jessica.jpg")),cipher); // enter your filename here
FileOutputStream fop=new FileOutputStream(new File("C:\\Users\\Larry\\Desktop\\Java\\diffie hellman\\src\\testEncrypt.jpg"));
int i;
while((i=cipt.read())!= -1)
{
fop.write(i);
}
cipher.init(Cipher.DECRYPT_MODE,secretKeySpec);
CipherInputStream cipt2 = new CipherInputStream(new FileInputStream(new File("C:\\Users\\Larry\\Desktop\\Java\\diffie hellman\\src\\testEncrypt.jpg")),cipher); // encryption of image
FileOutputStream fop2 = new FileOutputStream(new File("C:\\Users\\Larry\\Desktop\\Java\\diffie hellman\\src\\testDecrypt.jpg"));//decryption of images
int j;
while((j=cipt2.read())!=-1)
{
fop2.write(j);
}
}
public static BigInteger calculateSharedKey(BigInteger pk , BigInteger sk, BigInteger safePrime)
{
BigInteger sharedKey;
sharedKey = pk.modPow(sk, safePrime);
return sharedKey;
}
public static long generateSKA()
{
Random randomGenerator2=new Random();
long SKa = randomGenerator2.nextInt(1000000000);
return SKa;
}
public static long generateSKB()
{
Random randomGenerator3=new Random();
long SKb = randomGenerator3.nextInt(10000000);
return SKb;
}
public static BigInteger generatePkA(BigInteger g,BigInteger p,long skA)
{
BigInteger Pka,SK;
long secretKeyA = skA;
SK = BigInteger.valueOf(secretKeyA);
Pka=g.modPow(SK, p);
return Pka;
}
public static BigInteger generatePkB(BigInteger g,BigInteger p,long skB)
{
BigInteger Pkb,SK;
long secretKeyB = skB;
SK = BigInteger.valueOf(secretKeyB);
Pkb=g.modPow(SK, p);
return Pkb;
}
我的问题是如何合并我在托管 apache tomcat 的服务器上的 servlet 中编码的 DH 算法。我希望你们能用一些示例代码启发我，因为我真的很迷茫。
我的servlet代码如下
登录Servlet.java
> public class LoginServlet extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String un,pw;
un=request.getParameter("username");
pw=request.getParameter("password");
if(un.equalsIgnoreCase("hello") && pw.equals("world"))
{
out.print(1);
System.out.println(un);
System.out.println(pw);
}
else
{
out.print(0);
System.out.println(un);
System.out.println(pw);
}
} finally {
out.close();
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
@Override
public String getServletInfo() {
return "Short description";
}
}
希望大家能就这个问题给我指点一下。提前致谢！=)