http://tool.oschina.net/apidocs/apidoc?api=jdk-zh
package cn.com.gome.cashier.web; import java.lang.reflect.Method;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.security.Key;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.util.Arrays; import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec; import org.apache.commons.codec.binary.Base64;
import org.junit.Test; import cn.com.gome.common.security.base64.Base64Util; /**
* javax.crypto.spec.SecretKeySpec(implements KeySpec,SecretKey)
* java.security.spec.KeySpec, javax.crypto.SecretKey（extends java.security.Key）
* java.security.Key
*/
public class MyTestDemo {
private static String charset = "utf-8"; /**
* HMAC(Hash Message Authentication Code，散列消息鉴别码，基于密钥的Hash算法的认证协议
*/
@Test
public void test2(){
String str = "12345678901234567890qwqqq";
String encr = encrypt(str, "qazwsxedcrfvtgby");
String encr2 = encrypt16no(str, "qazwsxedcrfvtgby");
String encr3 = encrypt16(str, "qazwsxedcrfvtgby");
System.out.println("加密："+encr);
System.out.println("加密："+encr2);
System.out.println("加密："+encr3);
String dec = decrypt(encr, "qazwsxedcrfvtgby");
System.out.println("解密：" + dec); }
//AES对称加密 kgen.init()加不加keySize的区别 SecureRandom new与setSeed的区别
private static String encrypt(String password, String securityKey) {
byte[] crypted = null;
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");//实例化一个用AES加密算法的密钥生成器
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG","SUN");
secureRandom.setSeed(securityKey.getBytes());
kgen.init(secureRandom); SecretKey secretKey = kgen.generateKey();
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
crypted= cipher.doFinal(password.getBytes(charset));
} catch (Exception e) {
System.out.println(e.toString());
}
try {
return new String(encodeBase64(crypted)).replace(" ", "");
} catch (Exception e) {
e.printStackTrace();
}
return "";
}
//
AES算法在windows下可以正常加密、解密，上传到服务器之后，无法正常工作，每次加密的结果都是随机的
经检查发现，是加密的密钥在Linux下随机生成造成的, 不建议使用
private static String encrypt16no(String password, String securityKey) {
byte[] crypted = null;
try {
// 秘钥位数没限制
KeyGenerator kgen = KeyGenerator.getInstance("AES");//实例化一个用AES加密算法的密钥生成器
kgen.init(128, new SecureRandom(securityKey.getBytes()));//使用用户提供的password初始化此密钥生成器，使其具有确定的密钥大小128字节
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG","SUN"); 建议使用该方式
secureRandom.setSeed(securityKey.getBytes());
kgen.init(secureRandom);
SecretKey secretKey = kgen.generateKey();//生成一个密钥。
byte[] enCodeFormat = secretKey.getEncoded();//返回基本编码格式的密钥，如果此密钥不支持编码，则返回 null
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");//根据给定的enCodeFormat字节数组构造一个用AES算法加密的密钥。
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
cipher.init(Cipher.ENCRYPT_MODE, key);// 可以用 secretKey 以加密的方式用密钥初始化此 Cipher。
crypted = cipher.doFinal(password.getBytes("utf-8"));
} catch (Exception e) {
System.out.println(e.toString());
}
try {
return new String(encodeBase64(crypted)).replace(" ", "");
} catch (Exception e) {
e.printStackTrace();
}
return "";
}
private static String encrypt16(String password, String securityKey) {
byte[] crypted = null;
try {
// 秘钥必须为16位
SecretKeySpec keys = new SecretKeySpec(securityKey.getBytes(),
"AES");
Cipher.getInstance("AES/ECB/PKCS5Padding");//调用静态工厂方法得到Cipher对象
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, keys);// ENCRYPT_MODE,加密数据
crypted = cipher.doFinal(password.getBytes());
} catch (Exception e) {
System.out.println(e.toString());
}
try {
return new String(encodeBase64(crypted)).replace(" ", "");
} catch (Exception e) {
e.printStackTrace();
}
return "";
}
private static String decrypt(String input, String securityKey) {
byte[] output = null;
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(securityKey.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec keys = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES"); // SecretKeySpec keys = new SecretKeySpec(securityKey.getBytes(),
// "AES");
// Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); // Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.DECRYPT_MODE, secretKey);// DECRYPT_MODE,解密数据
output = cipher.doFinal(decodeBase64(input));
} catch (Exception e) {
System.out.println(e.toString());
return "";
}
return new String(output);
} /**
* BigInteger位运算 对称加解密,A、B的位运算为C，则C、B的位运算为A，C、A的位运算为B
*/
//@Test
public void testBigInteger(){
String str = "asd";
System.out.println(Arrays.toString(str.getBytes()));
String es = encrypt(str);
System.out.println("密文："+es);
System.out.println(decrypt(es)); //i=15转成二进制是1111，j=2转成二进制是0010，根据异或的运算规则得到的是1101，转成十进制就是13 两个操作数的位中，相同则结果为0，不同则结果为1 this ^ val
BigInteger i = (new BigInteger("15")).xor( (new BigInteger("2")));
System.out.println(i+" "+i.toString(10));//10进制表示
i = (new BigInteger("13")).xor( (new BigInteger("2")));
System.out.println(i+" "+i.toString(10));//10进制表示
}
private static final int RADIX = 16;
private static final String SEED = "0933910847463829232312312";
private static final String encrypt(String password) {
BigInteger bi_passwd = new BigInteger(password.getBytes());// 将包含 BigInteger 的二进制补码表示形式的 byte 数组转换为 BigInteger
BigInteger bi_seed = new BigInteger(SEED);
BigInteger bi_resu = bi_seed.xor(bi_passwd);// 位运算，种子在外、密码在内，按位运算符 异或
System.out.println("bi_passwd: "+bi_passwd);
System.out.println("bi_seed:"+bi_seed);
System.out.println("bi_resu:"+bi_resu);
return bi_resu.toString(RADIX);//返回16进制表示形式
}
private static final String decrypt(String encrypted) {
BigInteger bi_confuse = new BigInteger(SEED);
try {
BigInteger bi_r1 = new BigInteger(encrypted, RADIX);//将16进制密文转换为BigInteger
BigInteger bi_r0 = bi_r1.xor(bi_confuse);// 位运算，种子在内、密码在外
System.out.println("bi_r1:"+bi_r1);
System.out.println("bi_r0:"+bi_r0);
return new String(bi_r0.toByteArray());//将结果转换为字节数组，进而转换为字符串
} catch (Exception e) {
return "";
}
} /**
*信息-摘要算法,为计算机安全领域广泛使用的一种散列函数，用于确保信息传输完整一致。是计算机广泛使用的杂凑算法之一（又译摘要算法、哈希算法）
*1、压缩性：任意长度的数据，算出的MD5值长度都是固定的。
2、容易计算：从原数据计算出MD5值很容易。
3、抗修改性：对原数据进行任何改动，哪怕只修改1个字节，所得到的MD5值都有很大区别。
4、强抗碰撞：已知原数据和其MD5值，想找到一个具有相同MD5值的数据（即伪造数据）是非常困难的。
遗留：SHA
*/
//@Test
public void testMd5(){
String str = "是地方萨芬撒大哥啊啊sdfasdasdfasdff34r4433333335v4ffffffffffffffffffffffffffffffff";
try {
String str1 = encodeMessage(str);
System.out.println(str1); //以上代码就可以实现MD5摘要了。由于摘要的结果是字节数组，并不是我们常见的字符串，所以还有工作要做。字节数组转字符串，还不简单
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
byte[] md5Bytes = messageDigest.digest(str.getBytes(Charset.forName("UTF-8")));
for (byte b : md5Bytes) {
System.out.print(b);
}
//MD5摘要的结果是一个128bit的大整数
System.out.println(toHex2(md5Bytes));
System.out.println(BytesConvertToHexString(md5Bytes)); } catch (Exception e) {
e.printStackTrace();
}
}
//MD5摘要字节转换为字符串
private static String toHex2(byte[] bytes) {
final char[] HEX_DIGITS = "0123456789ABCDEF".toCharArray();
StringBuilder ret = new StringBuilder(bytes.length * 2);
for (int i=0; i<bytes.length; i++) {
ret.append(HEX_DIGITS[(bytes[i] >> 4) & 0x0f]);
ret.append(HEX_DIGITS[bytes[i] & 0x0f]);
}
return ret.toString();
}
//MD5摘要字节转换为16进制字符串
private static String BytesConvertToHexString(byte [] bytes) {
StringBuffer sb = new StringBuffer();
for (byte aByte : bytes) {
String s=Integer.toHexString(0xff & aByte);
if(s.length()==1){
sb.append("0"+s);
}else{
sb.append(s);
}
}
return sb.toString();
} private static String encodeMessage(String data) throws Exception {
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(data.getBytes());
return toHex(md5.digest());
} private static String toHex(byte[] buffer) {
byte[] result = new byte[buffer.length * 2];
for (int i = 0; i < buffer.length; i++) {
byte[] temp = getHexValue(buffer[i]);
result[(i * 2)] = temp[0];
result[(i * 2 + 1)] = temp[1];
}
return new String(result).toUpperCase();
} private static byte[] getHexValue(byte b) {
int value = b;
if (value < 0) {
value = 256 + b;
}
String s = Integer.toHexString(value);
if (s.length() == 1) {
return new byte[] { 48, (byte) s.charAt(0) };
}
return new byte[] { (byte) s.charAt(0), (byte) s.charAt(1) };
} /**
* 以下为base64编码 base64只能算是一个编码算法，对数据内容进行编码来适合传输
*/
//@Test
public void testBase64() {
String str = "1qazxsw23edcqwertyuiopfdgdgdfgdsgergsdfgfhrtsdf";
String de = encode(str.getBytes());
System.out.println(de);
byte[] b = decode(de.getBytes());
System.out.println(new String(b)); String de2 = encodes(str.getBytes());
System.out.println(de2);
byte[] b2 = decodes(de2);
System.out.println(new String(b2)); } private static String encodeBase64(byte[] input) throws Exception {
Class clazz = Class
.forName("com.sun.org.apache.xerces.internal.impl.dv.util.Base64");
Method mainMethod = clazz.getMethod("encode", byte[].class);
mainMethod.setAccessible(true);
Object retObj = mainMethod.invoke(null, new Object[] { input });
return (String) retObj;
}
private static byte[] decodeBase64(String input) throws Exception {
Class clazz = Class
.forName("com.sun.org.apache.xerces.internal.impl.dv.util.Base64");
Method mainMethod = clazz.getMethod("decode", String.class);
mainMethod.setAccessible(true);
Object retObj = mainMethod.invoke(null, input);
return (byte[]) retObj;
} private static String encode(final byte[] bytes) {
return new String(Base64.encodeBase64(bytes));
}
private static byte[] decode(final byte[] bytes) {
return Base64.decodeBase64(bytes);
} private static String encodes(byte[] bstr) {
return new sun.misc.BASE64Encoder().encode(bstr);
}
private static byte[] decodes(String str) {
byte[] bt = null;
try {
sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
bt = decoder.decodeBuffer(str);
} catch (Exception e) {
e.printStackTrace();
}
return bt;
}
}