【JAVA】常用加解密算法总结及JAVA实现【BASE64,MD5,SHA,DES,3DES,AES,RSA】
BASE64
这其实是一种编解码方法，但是只要我们能够将原文变成肉眼不可识别的内容，其实就是一种加密的方法。
BASE64 的编码都是按字符串长度，以每 3 个 8 bit 的字符为一组，然后针对每组，首先获取每个字符的 ASCII 编码，然后将 ASCII 编码转换成 8 bit 的二进制，得到一组 3*8=24 bit 的字节。然后再将这 24 bit 划分为 4 个 6 bit 的字节，并在每个 6 bit 的字节前面都填两个高位 0，得到 4 个 8 bit 的字节，然后将这 4 个 8 bit 的字节转换成十进制，对照 BASE64 编码表 ，得到对应编码后的字符。
实现：
/**
* Project Name:thread
* File Name:Base64Util.java
* Package Name:enc.dec
* Date:2015年10月21日下午3:49:21
* Copyright (c) 2015, [email protected] All Rights Reserved.
*
*/
package enc.dec;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* ClassName:Base64Util
* Function: TODO ADD FUNCTION.
* Reason: TODO ADD REASON.
* Date: 2015年10月21日 下午3:49:21
*
* @author chiwei
* @version
* @since JDK 1.6
* @see
*/
public class Base64Util {
private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
.toCharArray();
/**
* data[]进行编码
*
* @param data
* @return
*/
public static String encode(byte[] data) {
int start = 0;
int len = data.length;
StringBuffer buf = new StringBuffer(data.length * 3 / 2);
int end = len - 3;
int i = start;
int n = 0;
while (i <= end) {
int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8)
| (((int) data[i + 2]) & 0x0ff);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append(legalChars[d & 63]);
i += 3;
if (n++ >= 14) {
n = 0;
buf.append(" ");
}
}
if (i == start + len - 2) {
int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append("=");
} else if (i == start + len - 1) {
int d = (((int) data[i]) & 0x0ff) << 16;
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append("==");
}
return buf.toString();
}
public static String encode(String data) {
try {
return encode(data.getBytes("UTF-8"));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private static int decode(char c) {
if (c >= 'A' && c <= 'Z')
return ((int) c) - 65;
else if (c >= 'a' && c <= 'z')
return ((int) c) - 97 + 26;
else if (c >= '0' && c <= '9')
return ((int) c) - 48 + 26 + 26;
else
switch (c) {
case '+':
return 62;
case '/':
return 63;
case '=':
return 0;
default:
throw new RuntimeException("unexpected code: " + c);
}
}
/**
* Decodes the given Base64 encoded String to a new byte array. The byte
* array holding the decoded data is returned.
*/
public static byte[] decode(String s) {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
decode(s, bos);
} catch (IOException e) {
throw new RuntimeException();
}
byte[] decodedBytes = bos.toByteArray();
try {
bos.close();
bos = null;
} catch (IOException ex) {
throw new RuntimeException(ex);
}
return decodedBytes;
}
private static void decode(String s, OutputStream os) throws IOException {
int i = 0;
int len = s.length();
while (true) {
while (i < len && s.charAt(i) <= ' ')
i++;
if (i == len)
break;
int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12)
+ (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));
os.write((tri >> 16) & 255);
if (s.charAt(i + 2) == '=')
break;
os.write((tri >> 8) & 255);
if (s.charAt(i + 3) == '=')
break;
os.write(tri & 255);
i += 4;
}
}
/**
* data[]进行编码
*
* @param data
* @return
*/
public static String Base64Encoder(byte[] data) {
int start = 0;
int len = data.length;
StringBuffer buf = new StringBuffer(data.length * 3 / 2);
int end = len - 3;
int i = start;
int n = 0;
while (i <= end) {
int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8)
| (((int) data[i + 2]) & 0x0ff);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append(legalChars[d & 63]);
i += 3;
if (n++ >= 14) {
// 不需要空格
n = 0;
}
}
if (i == start + len - 2) {
int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append("=");
} else if (i == start + len - 1) {
int d = (((int) data[i]) & 0x0ff) << 16;
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append("==");
}
return buf.toString();
}
public static void main(String[] args) {
System.out.println(encode("tree"));
System.out.println(new String(decode(encode("tree"))));
}
}
加解密
MD5
Message Digest Algorithm 5
MD5 是用来验证文件的一致性的
/**
* Project Name:thread
* File Name:MD5Util.java
* Package Name:enc.dec
* Date:2015年10月21日下午3:58:02
* Copyright (c) 2015, [email protected] All Rights Reserved.
*
*/
package enc.dec;
import java.security.MessageDigest;
/**
* ClassName:MD5Util
* Function: TODO ADD FUNCTION.
* Reason: TODO ADD REASON.
* Date: 2015年10月21日 下午3:58:02
*
* @author chiwei
* @version
* @since JDK 1.6
* @see
*/
public class MD5Util {
public static String getMD5(String source) {
String s = null;
char hexChar[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
'E', 'F' };
try {
MessageDigest md = MessageDigest.getInstance("MD5");
md.update(source.getBytes());// 使用指定的byte数组更新摘要
byte[] hashCalc = md.digest();// 完成哈希计算
char result[] = new char[16 * 2];// MD5结果返回的是32位字符串，每位是16进制表示的
int k = 0;
for (int i = 0; i < 16; i++) {// 循环16次，对每个字节进行操作转换
byte everyByte = hashCalc[i];
result[k++] = hexChar[everyByte >>> 4 & 0xf];// 对每个字节的高4位进行处理，逻辑右移，再相与
result[k++] = hexChar[everyByte & 0xf];// 低4位转换
}
s = new String(result);
} catch (Exception e) {
throw new RuntimeException(e);
}
return s;
}
public static void main(String[] args) {
System.out.println(getMD5("tree"));
}
}
SHA
Secure Hash Algorithm
SHA1
SHA-1 有两个特点：
不可以从消息摘要中复原信息
两个不同的消息，不会产生同样的消息摘要
SHA-1 是一种数据加密算法，主要是接收一段明文，然后以一种不可逆的方式将它转换成一段密文，也可以简单的理解为取一串输入码，并把它们转化为长度较短、位数固定的输出序列即散列值的过程。
对应的还有SHA-256，SHA-512，算法更加安全
/**
* Project Name:thread
* File Name:SHAUtil.java
* Package Name:enc.dec
* Date:2015年10月21日下午4:01:50
* Copyright (c) 2015, [email protected] All Rights Reserved.
*
*/
package enc.dec;
import java.security.MessageDigest;
/**
* ClassName:SHAUtil
* Function: TODO ADD FUNCTION.
* Reason: TODO ADD REASON.
* Date: 2015年10月21日 下午4:01:50
*
* @author chiwei
* @version
* @since JDK 1.6
* @see
*/
public class SHAUtil {
/** 算法种类 */
private final static String KEY_SHA1 = "SHA-1";
private final static String KEY_SHA256 = "SHA-256";
private final static String KEY_SHA512 = "SHA-512";
public static String encBySha1(String data) throws Exception {
// 创建具有指定算法名称的信息摘要
MessageDigest sha = MessageDigest.getInstance(KEY_SHA1);
// 使用指定的字节数组对摘要进行最后更新
sha.update(data.getBytes());
// 完成摘要计算
byte[] bytes = sha.digest();
// 将得到的字节数组变成字符串返回
return ByteUtil.byteArrayToHexString(bytes);
}
public static String encBySha256(String data) throws Exception {
// 创建具有指定算法名称的信息摘要
MessageDigest sha = MessageDigest.getInstance(KEY_SHA256);
// 使用指定的字节数组对摘要进行最后更新
sha.update(data.getBytes());
// 完成摘要计算
byte[] bytes = sha.digest();
// 将得到的字节数组变成字符串返回
return ByteUtil.byteArrayToHexString(bytes);
}
public static String encBySha512(String data) throws Exception {
// 创建具有指定算法名称的信息摘要
MessageDigest sha = MessageDigest.getInstance(KEY_SHA512);
// 使用指定的字节数组对摘要进行最后更新
sha.update(data.getBytes());
// 完成摘要计算
byte[] bytes = sha.digest();
// 将得到的字节数组变成字符串返回
return ByteUtil.byteArrayToHexString(bytes);
}
public static void main(String[] args) throws Exception {
String key = "123";
System.out.println(encBySha1(key));
System.out.println(encBySha256(key));
System.out.println(encBySha512(key));
}
}
DES,3DES,AES对称加密
DES 算法把 64 位的明文输入块变为 64 位的密文输出块，它所使用的密钥也是 64 位，其算法主要分为两步：
初始置换
其功能是把输入的 64 位数据块按位重新组合,并把输出分为 L0、R0 两部分，每部分各长 32 位，其置换规则为将输入的第 58 位换到第一位，第 50 位换到第 2 位 …… 依此类推,最后一位是原来的第 7 位。L0、R0 则是换位输出后的两部分，L0 是输出的左 32 位，R0 是右 32 位，例：设置换前的输入值为 D1 D2 D3 …… D64，则经过初始置换后的结果为：L0 = D58 D50 …… D8；R0 = D57 D49 …… D7。
逆置换
经过 16 次迭代运算后，得到 L16、R16，将此作为输入，进行逆置换，逆置换正好是初始置换的逆运算，由此即得到密文输出。
3DES，也就是“Triple DES”，中文名“三重数据加密算法”，它相当于是对每个数据块应用三次 DES 加密算法。由于计算机运算能力的增强，原版 DES 密码的密钥长度变得容易被暴力破解；3DES 即是设计用来提供一种相对简单的方法，即通过增加 DES 的密钥长度来避免类似的攻击，而不是设计一种全新的块密码算法。
AES，全称为“Advanced Encryption Standard”，中文名“高级加密标准”，在密码学中又称 Rijndael 加密法，是美国联邦政府采用的一种区块加密标准。AES 加密算法作为新一代的数据加密标准汇聚了强安全性、高性能、高效率、易用和灵活等优点。AES 设计有三个密钥长度：128，192，256 位。相对而言，AES 的 128 密钥比 DES 的 56 密钥强了 1021 倍。
/**
* Project Name:thread
* File Name:DESUtil.java
* Package Name:enc.dec
* Date:2015年10月21日下午4:17:14
* Copyright (c) 2015, [email protected] All Rights Reserved.
*
*/
package enc.dec;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.SecretKeySpec;
/**
* ClassName:DESUtil
* Function: TODO ADD FUNCTION.
* Reason: TODO ADD REASON.
* Date: 2015年10月21日 下午4:17:14
*
* @author chiwei
* @version
* @since JDK 1.6
* @see
*/
public class DESUtil {
private final static String KEY_DES = "DES";
private static final String KEY_3_DES = "DESede";
private final static String KEY_AES = "AES"; // 测试
//长度8字节
private final static String DES_KEY = "12345678";
//长度24字节
private final static String DES_3_KEY = "213456781234567812345678";
//长度16，24，32字节
private final static String AES_KEY = "1234567812345678";
private static byte[] decByDes(byte[] data) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom random = new SecureRandom();
DESKeySpec desKey = new DESKeySpec(DES_KEY.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_DES);
SecretKey securekey = keyFactory.generateSecret(desKey);
Cipher cipher = Cipher.getInstance(KEY_DES);
cipher.init(Cipher.DECRYPT_MODE, securekey, random);
return cipher.doFinal(data);
}
private static byte[] encByDes(byte[] data) throws Exception {
DESKeySpec desKey = new DESKeySpec(DES_KEY.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_DES);
SecretKey securekey = keyFactory.generateSecret(desKey);
Cipher cipher = Cipher.getInstance(KEY_DES);
cipher.init(Cipher.ENCRYPT_MODE, securekey);
return cipher.doFinal(data);
}
private static byte[] decBy3Des(byte[] data) throws Exception {
SecureRandom random = new SecureRandom();
SecretKey deskey = new SecretKeySpec(DES_3_KEY.getBytes(), KEY_3_DES);
Cipher cipher = Cipher.getInstance(KEY_3_DES);
cipher.init(Cipher.DECRYPT_MODE, deskey, random);
return cipher.doFinal(data);
}
private static byte[] encBy3Des(byte[] data) throws Exception {
SecureRandom random = new SecureRandom();
SecretKey deskey = new SecretKeySpec(DES_3_KEY.getBytes(), KEY_3_DES);
Cipher cipher = Cipher.getInstance(KEY_3_DES);
cipher.init(Cipher.ENCRYPT_MODE, deskey, random);
return cipher.doFinal(data);
}
private static byte[] decByAes(byte[] data) throws Exception {
SecretKey deskey = new SecretKeySpec(AES_KEY.getBytes(), KEY_AES);
Cipher cipher = Cipher.getInstance(KEY_AES);
cipher.init(Cipher.DECRYPT_MODE, deskey);
return cipher.doFinal(data);
}
private static byte[] encByAes(byte[] data) throws Exception {
SecretKey deskey = new SecretKeySpec(AES_KEY.getBytes(), KEY_AES);
Cipher cipher = Cipher.getInstance(KEY_AES);
cipher.init(Cipher.ENCRYPT_MODE, deskey);
return cipher.doFinal(data);
}
public static void main(String[] args) throws Exception {
System.out.println("DES密钥:\n" + DES_KEY);
System.out.println("DES密钥字节长度:\n" + DES_KEY.getBytes().length);
String word = "123";
System.out.println("原文：" + word);
System.out.println("=============DES=============");
byte b[] = encByDes(word.getBytes());
String encWord = new String(b);
System.out.println("加密后：" + encWord);
System.out.println("解密后：" + new String(decByDes(b)));
System.out.println("=============3DES=============");
System.out.println("3DES密钥:" + DES_3_KEY);
System.out.println("3DES密钥字节长度:" + DES_3_KEY.getBytes().length);
b = encBy3Des(word.getBytes());
encWord = new String(b);
System.out.println("加密后：" + encWord);
System.out.println("解密后：" + new String(decBy3Des(b)));
System.out.println("=============AES=============");
System.out.println("AES密钥:" + AES_KEY);
System.out.println("AES密钥字节长度:" + AES_KEY.getBytes().length);
b = encByAes(word.getBytes());
encWord = new String(b);
System.out.println("加密后：" + encWord);
System.out.println("解密后：" + new String(decByAes(b)));
}
}
RSA非对称加密
/**
* Project Name:thread
* File Name:RSAUtil.java
* Package Name:enc.dec
* Date:2015年10月22日上午9:21:01
* Copyright (c) 2015, [email protected] All Rights Reserved.
*
*/
package enc.dec;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
import com.alibaba.fastjson.JSONObject;
/**
* ClassName:RSAUtil
* Function: TODO ADD FUNCTION.
* Reason: TODO ADD REASON.
* Date: 2015年10月22日 上午9:21:01
*
* @author chiwei
* @version
* @since JDK 1.6
* @see
*/
public class RSAUtil {
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";
/**
* 签名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* 获取公钥的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
private static final int keyLen = 512;// 密钥长度
/**
* 获取私钥的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = keyLen / 8 - 11;
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = keyLen / 8;
/**
*
* genKeyPair:().
* 生成公司钥对，返回的是经过BASE64编码的密钥
* @author chiwei
* @return
* @throws Exception
* @since JDK 1.6
*/
public static Map genKeyPair() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(keyLen);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map keyMap = new HashMap(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
*
* sign:().
* 用私钥进行签名，返回BASE64编码的内容
* @author chiwei
* @param data
* @param privateKey
* @return
* @throws Exception
* @since JDK 1.6
*/
public static String sign(byte[] data, String privateKey) throws Exception {
byte[] keyBytes = Base64Util.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return Base64Util.encode(signature.sign());
}
/**
*
* verify:().
* 用公钥对签名进行验证
* @author chiwei
* @param data
* @param publicKey
* @param sign
* @return
* @throws Exception
* @since JDK 1.6
*/
public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
byte[] keyBytes = Base64Util.decode(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data);
return signature.verify(Base64Util.decode(sign));
}
/**
*
* decryptByPrivateKey:().
* 私钥解密
* @author chiwei
* @param encryptedData
* @param privateKey
* @return
* @throws Exception
* @since JDK 1.6
*/
public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
throws Exception {
byte[] keyBytes = Base64Util.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/**
*
* decryptByPublicKey:().
* 公钥解密
* @author chiwei
* @param encryptedData
* @param publicKey
* @return
* @throws Exception
* @since JDK 1.6
*/
public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
throws Exception {
byte[] keyBytes = Base64Util.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/**
*
* encryptByPublicKey:().
* 公钥加密
* @author chiwei
* @param data
* @param publicKey
* @return
* @throws Exception
* @since JDK 1.6
*/
public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
byte[] keyBytes = Base64Util.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/**
*
* encryptByPrivateKey:().
* 私钥加密
* @author chiwei
* @param data
* @param privateKey
* @return
* @throws Exception
* @since JDK 1.6
*/
public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {
byte[] keyBytes = Base64Util.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/**
*
* getPrivateKey:().
* 获取BASE64编码的私钥
* @author chiwei
* @param keyMap
* @return
* @throws Exception
* @since JDK 1.6
*/
public static String getPrivateKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return Base64Util.encode(key.getEncoded());
}
/**
*
* getPublicKey:().
* 获取BASE64编码的公钥
* @author chiwei
* @param keyMap
* @return
* @throws Exception
* @since JDK 1.6
*/
public static String getPublicKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return Base64Util.encode(key.getEncoded());
}
public static void main(String args[]) {
JSONObject json = new JSONObject();
json.put("deviceId", "1");
json.put("clientVersion", "2");
json.put("platform", "1");
JSONObject position = new JSONObject();
position.put("location_latitude_key", "10.98");
position.put("location_longtitude_key", "110.98");
json.put("position", position);
json.put("city", "杭州市");
json.put("locatedAddress", "");
json.put("romVersion", "1");
json.put("commandId", 0x125);
json.put("userId", 10049);
json.put("orderId", 10053);
System.out.println(json);
String publicKey = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIc7AHO19/BdTKI18QDeqOxHCNHI w8+2C15kvE5h+kYoQxCq3IdVDsJJKFJSAtfOe7WHgLUDOpAZaHcUnpW7HpUC AwEAAQ==";// "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCZozfHvyz7LZIAo7BPX2HE DHc4CZR9UIwPC/omfaJ62f8l2na+YRKQHBE220+RQfqupVMKmy7QYo+hAjs4 MqCgCedqyWBwHhrhTbQp5FuZ/xaqFCuz/ntyYzz7NrYoD3ijtwBXUrx6kTJf xtkB/Nhd317JHuzxPR9bNUj3K5pLfwIDAQAB";
String privateKey = "MIIBUwIBADANBgkqhkiG9w0BAQEFAASCAT0wggE5AgEAAkEAhzsAc7X38F1M ojXxAN6o7EcI0cjDz7YLXmS8TmH6RihDEKrch1UOwkkoUlIC1857tYeAtQM6 kBlodxSelbselQIDAQABAkBwhC4XGMPoMajumpUhFSJWHbB/5FzQOXbyHjzz tt/neKONwuB25QJ+DehwtKGnjDtcrSlUbNYIc0L95eKPGvJBAiEA39pNrReU WThfcQkz1TEmL+Pqh09Uf5KdkUJFRn3rEsUCIQCapplvyKoWiC2//J8NXUds 1SyNv5+vsXlwhtPqJsNZkQIgEEIy0hecVr6ZcARTF3DybRgIuLsyT/G+MAa4 MV6D7GECICocr6+G3vofvwWGjvEes3JpYiZ/Rcab90uzC0W5pHxhAiAvPq16 AvszXkXVZXgvEHoyG2qvbj0I7VkCsHI8C0E1xQ==";// "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAJmjN8e/LPst kgCjsE9fYcQMdzgJlH1QjA8L+iZ9onrZ/yXadr5hEpAcETbbT5FB+q6lUwqb LtBij6ECOzgyoKAJ52rJYHAeGuFNtCnkW5n/FqoUK7P+e3JjPPs2tigPeKO3 AFdSvHqRMl/G2QH82F3fXske7PE9H1s1SPcrmkt/AgMBAAECf0sEZzghINWE asXlJzGaYSJY891o0BhgPAMc1gf1UGCsEOlqwpAy1d2H1t/yNee3T6/3CZUk MLePaJI1hLTsA4FcGzEWKUy7Hn2CqIjUzkJdax6CYXlK0hcoI47fiCr7Wtcx U/6P1uN+shA5ICHF0nZYJ2vEO1Vw/xMVGnLIRykCQQDwHJ0yOJZde7nZxo56 xka2C1tfMNjziXkdFH6EGfaiT0iJkJ+Kd11m0LukUxLPo5U1O63ZYkWOtFen wL2FmJTzAkEAo83FAO23KDZAyaPJg4K1PWqScF8+BDK51QxmJR0iCcl2umck jTfnO53wE8zjGNH/nqKQK6D+RUs8vEWaI37CRQJBAKKEW4mQb4XappJWKD3F UjsJONEXOOCtncInCvLSt/JoA0rJDpMj854Rjc/NQqAzslwThrnqH/ZU7jdm 52AzRC0CQB62djm2WKExivRDwYTm/RSG5u4q7XXcDPvlV0GeNMOhAqHwtOnF kZWcB2evAuWkeklEMcP8a7CSatDiPARrwAECQQC0SMsT/xukGzOh4SkHEirN bdFwdLdFeJf+8O3Tsf7iYlTNhnGEgTLQeaf3xOoivGtJEXZwT7vJWtiTUXRW 8P1v";
try {
// Map key = genKeyPair();
// publicKey = getPublicKey(key);
// privateKey = getPrivateKey(key);
System.out.println("公钥-->" + publicKey);
System.out.println("私钥-->" + privateKey);
System.out.println("待加密的字符串：" + json);
byte[] enBy = encryptByPublicKey(json.toJSONString().getBytes(), publicKey);
String enStr = new String(enBy, "UTF-8");
System.out.println("加密后：" + enStr);
String enEncode = Base64Util.encode(enBy);
System.out.println("加密后编码内容：" + enEncode);
byte[] deBy = decryptByPrivateKey(Base64Util.decode(enEncode), privateKey);
System.out.println("解密后：" + new String(deBy));
System.out.println("解密后编码内容：" + Base64Util.encode(deBy));
String sign = sign(enBy,privateKey);
System.out.println("签名："+sign);
System.out.println("对签名验证："+verify(enBy, publicKey, sign));
System.out.println("BASE64编码密文摘要："+MD5Util.getMD5(enEncode));
} catch (Exception e) {
e.printStackTrace();
}
}
}
数据加密：
为了保证数据的安全性，不会泄露数据的真是内容
数据摘要：
为了确保数据中途没有被篡改过，数据的内容时完整的正确的
数据签名：
为了保证数据是对方过来的，而不是从别的地方来的
在真实的互联网应用中，加密场景非常重要
1、对数据加密
2、对密文生成摘要
3、对摘要进行签名
4、将密文和签名一起发送
这样就保证了数据的安全性
这里还有一个唯一的漏洞就是接收方的公钥被人替换了，所以就出现了证书认证中心
确保公钥的安全性，在发送数据的时候加上数字证书。