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帮人问 J2ME (MICRO EDITION) 实现 加密 数据传输 问题

摘要: 帮人问 J2ME (MICRO EDITION) 实现 加密 数据传输 问题

帮别人问的，不用编好,给个解决的头绪就可以了

用J2ME (MICRO EDITION) 实现 加密 数据传输

有基本的JAVA CLASS: LANG, UTIL, IO
能不能编写简单的加密算发?最好是公/私钥加密,但是不用实现钥的生成,只要有10对,
可以演示就行

如果不可以,在网上能找到的IMPLEMENTATION(WWW.BOUNCYCASTLE.ORG),但是太大了,要
怎么样简化一下,如何放入JAVA WIRELESS TOOLKIT (KTOOLBAR 程序的名字)和以有的程
序一起运行?

谢谢

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up一下，希望有人指点

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public class IDEA {

public IDEA() {
}

public byte[] ideaEncrypt(byte[] bytekey, byte[] inputBytes, boolean flag) {
byte[] encryptCode = new byte[8];
// 分解子密钥
int[] key = get_subkey(flag, bytekey);
// 进行加密操作
encrypt(key, inputBytes, encryptCode);
// 返回加密数据
return encryptCode;
}

private int bytesToInt(byte[] inBytes, int startPos) {
return ((inBytes[startPos] << 8) & 0xff00)
+ (inBytes[startPos + 1] & 0xff);
}

private void intToBytes(int inputInt, byte[] outBytes, int startPos) {
outBytes[startPos] = (byte) (inputInt >>> 8);
outBytes[startPos + 1] = (byte) inputInt;
}

private int x_multiply_y(int x, int y) {
if (x == 0) {
x = 0x10001 - y;
} else if (y == 0) {
x = 0x10001 - x;
} else {
int tmp = x * y;
y = tmp & 0xffff;
x = tmp >>> 16;
x = (y - x) + ((y < x) ? 1 : 0);
}
return x & 0xffff;
}

private void encrypt(int[] key, byte[] inbytes, byte[] outbytes) {
int k = 0;
int a = bytesToInt(inbytes, 0);
int b = bytesToInt(inbytes, 2);
int c = bytesToInt(inbytes, 4);
int d = bytesToInt(inbytes, 6);

for (int i = 0; i < 8; i++) {
a = x_multiply_y(a, key[k++]);
b += key[k++];
b &= 0xffff;
c += key[k++];
c &= 0xffff;
d = x_multiply_y(d, key[k++]);

int tmp1 = b;
int tmp2 = c;
c ^= a;
b ^= d;
c = x_multiply_y(c, key[k++]);
b += c;
b &= 0xffff;
b = x_multiply_y(b, key[k++]);
c += b;
c &= 0xffff;
a ^= b;
d ^= c;
b ^= tmp2;
c ^= tmp1;
}

intToBytes(x_multiply_y(a, key[k++]), outbytes, 0);
intToBytes(c + key[k++], outbytes, 2);
intToBytes(b + key[k++], outbytes, 4);
intToBytes(x_multiply_y(d, key[k]), outbytes, 6);
}

private int[] encrypt_subkey(byte[] byteKey) {
int[] key = new int[52];

if (byteKey.length < 16) {
byte[] tmpkey = new byte[16];
System.arraycopy(byteKey, 0, tmpkey,
tmpkey.length - byteKey.length, byteKey.length);
byteKey = tmpkey;
}

for (int i = 0; i < 8; i++) {
key[i] = bytesToInt(byteKey, i * 2);
}
for (int j = 8; j < 52; j++) {
if ((j & 0x7) < 6) {
key[j] = (((key[j - 7] & 0x7f) << 9) | (key[j - 6] >> 7)) & 0xffff;
} else if ((j & 0x7) == 6) {
key[j] = (((key[j - 7] & 0x7f) << 9) | (key[j - 14] >> 7)) & 0xffff;
} else {
key[j] = (((key[j - 15] & 0x7f) << 9) | (key[j - 14] >> 7)) & 0xffff;
}
}

return key;
}

private int fun_a(int a) {
if (a < 2) {
return a;
}
int b = 1;
int c = 0x10001 / a;
for (int i = 0x10001 % a; i != 1;) {
int d = a / i;
a %= i;
b = (b + (c * d)) & 0xffff;
if (a == 1) {
return b;
}
d = i / a;
i %= a;
c = (c + (b * d)) & 0xffff;
}
return (1 - c) & 0xffff;
}

private int fun_b(int b) {
return (0 - b) & 0xffff;
}

private int[] uncrypt_subkey(int[] key) {
int dec = 52;
int asc = 0;
int[] unkey = new int[52];
int aa = fun_a(key[asc++]);
int bb = fun_b(key[asc++]);
int cc = fun_b(key[asc++]);
int dd = fun_a(key[asc++]);
unkey[--dec] = dd;
unkey[--dec] = cc;
unkey[--dec] = bb;
unkey[--dec] = aa;

for (int k1 = 1; k1 < 8; k1++) {
aa = key[asc++];
bb = key[asc++];
unkey[--dec] = bb;
unkey[--dec] = aa;
aa = fun_a(key[asc++]);
bb = fun_b(key[asc++]);
cc = fun_b(key[asc++]);
dd = fun_a(key[asc++]);
unkey[--dec] = dd;
unkey[--dec] = bb;
unkey[--dec] = cc;
unkey[--dec] = aa;
}

aa = key[asc++];
bb = key[asc++];
unkey[--dec] = bb;
unkey[--dec] = aa;
aa = fun_a(key[asc++]);
bb = fun_b(key[asc++]);
cc = fun_b(key[asc++]);
dd = fun_a(key[asc]);
unkey[--dec] = dd;
unkey[--dec] = cc;
unkey[--dec] = bb;
unkey[--dec] = aa;

return unkey;
}

private int[] get_subkey(boolean flag, byte[] bytekey) {
if (flag) {
return encrypt_subkey(bytekey);
} else {
return uncrypt_subkey(encrypt_subkey(bytekey));
}
}

public static void main(String[] args) {
IDEA idea = new IDEA();
byte[] key = { (byte) 0x11, (byte) 0x22, (byte) 0x33, (byte) 0x44,
(byte) 0x55, (byte) 0x66, (byte) 0x77, (byte) 0x88,
(byte) 0x99, (byte) 0xaa, (byte) 0xbb, (byte) 0xcc,
(byte) 0xdd, (byte) 0xee, (byte) 0xff, (byte) 0x00 };
byte[] a = { (byte) 0x12, (byte) 0x34, (byte) 0x56, (byte) 0x78,
(byte) 0x21, (byte) 0x43, (byte) 0x65, (byte) 0x87 };
byte[] b = idea.ideaEncrypt(key, a, true);
byte[] c = idea.ideaEncrypt(key, b, false);
for (int i = 0; i < 8; i++) {
System.out.println("--------------");
System.out.println((int) a[i]);
System.out.println((int) c[i]);
System.out.println("--------------");
}
}
}
声明：这是一个对称加密的

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IMPLEMENTATION(WWW.BOUNCYCASTLE.ORG),

删除掉不用的类就是了

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