【Java】java实现RC4加解密
RC4属于对称可逆加密（就是加密解密的密钥一样）使用方法:
try
{
String encryStr = RC4Util.encryRC4String("测试", "123456", "UTF-8");
System.out.println("加密后得到得字符串：" + encryStr);
}
catch (UnsupportedEncodingException e)
{}
String decryStr = RC4Util.decryRC4(encryStr, "123456");
System.out.println("解密后得到得字符串："+decryStr);
工具类:
class RC4Util {
public static String encryRC4String(String data, String key, String chartSet) throws UnsupportedEncodingException {
if (data == null || key == null) {
return null;
}
return toHexString(asString(encryRC4Byte(data, key, chartSet)));
}
public static byte[] encryRC4Byte(String data, String key, String chartSet) throws UnsupportedEncodingException {
if (data == null || key == null) {
return null;
}
if (chartSet == null || chartSet.isEmpty()) {
byte bData[] = data.getBytes();
return RC4Base(bData, key);
} else {
byte bData[] = data.getBytes(chartSet);
return RC4Base(bData, key);
}
}
public static String decryRC4(String data, String key) {
if (data == null || key == null) {
return null;
}
return new String(RC4Base(HexString2Bytes(data), key), StandardCharsets.UTF_8);
}
public static String decryRC4(byte[] data, String key) {
if (data == null || key == null) {
return null;
}
return asString(RC4Base(data, key));
}
private static String asString(byte[] buf) {
StringBuffer strbuf = new StringBuffer(buf.length);
for (byte b : buf) {
strbuf.append((char) b);
}
return strbuf.toString();
}
private static byte[] initKey(String aKey) {
byte[] bkey = aKey.getBytes();
byte state[] = new byte;
for (int i = 0; i < 256; i++) {
state = (byte) i;
}
int index1 = 0;
int index2 = 0;
if (bkey.length == 0) {
return null;
}
for (int i = 0; i < 256; i++) {
index2 = ((bkey & 0xff) + (state & 0xff) + index2) & 0xff;
byte tmp = state;
state = state;
state = tmp;
index1 = (index1 + 1) % bkey.length;
}
return state;
}
private static String toHexString(String s) {
String str = "";
for (int i = 0; i < s.length(); i++) {
int ch = (int) s.charAt(i);
String s4 = Integer.toHexString(ch & 0xFF);
if (s4.length() == 1) {
s4 = '0' + s4;
}
str = str + s4;
}
return str;
}
private static byte[] HexString2Bytes(String src) {
int size = src.length();
byte[] ret = new byte;
byte[] tmp = src.getBytes(StandardCharsets.UTF_8);
for (int i = 0; i < size / 2; i++) {
ret = uniteBytes(tmp, tmp);
}
return ret;
}
private static byte uniteBytes(byte src0, byte src1) {
char _b0 = (char) Byte.decode("0x" + new String(new byte[]{src0})).byteValue();
_b0 = (char) (_b0 << 4);
char _b1 = (char) Byte.decode("0x" + new String(new byte[]{src1})).byteValue();
return (byte) (_b0 ^ _b1);
}
private static byte[] RC4Base(byte[] input, String mKkey) {
int x = 0;
int y = 0;
byte key[] = initKey(mKkey);
int xorIndex;
byte[] result = new byte;
for (int i = 0; i < input.length; i++) {
x = (x + 1) & 0xff;
y = ((key & 0xff) + y) & 0xff;
byte tmp = key;
key = key;
key = tmp;
xorIndex = ((key & 0xff) + (key & 0xff)) & 0xff;
result = (byte) (input ^ key);
}
return result;
}
}
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