給大家分享一個java分段加解密的工具類
該類也是綜合網上相關類寫出來的 感謝各位,所以我也來奉獻了
還有一個測試用的main方法
package example;
/**
* 創建時間:2019/01/10
* 創建人:Administrator
* 描述:
*/
import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
/**
* 1、公鑰加密,私鑰解密用於信息加密
* 2、私鑰加密,公鑰解密用於數字簽名
*/
public class RsaTool
{
/**
* 測試方法
*/
public static void main(String[] args)
{
// Map<String, Object> map = new HashMap<String, Object>();
// map = RsaTool.init();
// System.out.println("公鑰:"+RsaTool.getPublicKey(map));
// System.out.println("私鑰:"+RsaTool.getPrivateKey(map));
//由前四行代碼獲得公、私密鑰
String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCLNbmKl9/gLn7Bef/xtUkshC1WyrLZLRpXCcFYR1gQi0isWsZBTicC4efBOkkNG3r+1ue0gvtuU/tjREFGf4Y7HaKHGb5tNCOlMNeNjM5YLRwLFqrUSsQyD4rj4eua1ltearr24R0HilnTvnQm6Z/UY0s21vdOUFQBPY0GNAa+0wIDAQAB";
String privateKey = "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";
String str = "你好6666666666666666";
// 公鑰加密,私鑰解密
String enStr1 = RsaTool.encryptByPublicKey(str, publicKey);
System.out.println("公鑰加密後:" + enStr1);
String deStr1 = RsaTool.decryptByPrivateKey(enStr1, privateKey);
System.out.println("私鑰解密後:" + deStr1);
// 私鑰加密,公鑰解密
String enStr2 = RsaTool.encryptByPrivateKey(str, privateKey);
System.out.println("私鑰加密後:" + enStr2);
String deStr2 = RsaTool.decryptByPublicKey(enStr2, publicKey);
System.out.println("公鑰解密後:" + deStr2);
// 產生簽名
String sign = sign(enStr2, privateKey);
System.out.println("簽名:" + sign);
// 驗證簽名
boolean status = verify(enStr2, publicKey, sign);
System.out.println("狀態:" + status);
}
//定義加密方式
public static final String KEY_RSA = "RSA";
//定義公鑰關鍵詞
public static final String KEY_RSA_PUBLICKEY = "RSAPublicKey";
//定義私鑰關鍵詞
public static final String KEY_RSA_PRIVATEKEY = "RSAPrivateKey";
//定義簽名算法
private final static String KEY_RSA_SIGNATURE = "MD5withRSA";
/**
* **
* RSA最大加密大小
*/
private final static int MAX_ENCRYPT_BLOCK = 117;
/**
* **
* RSA最大解密大小
*/
private final static int MAX_DECRYPT_BLOCK = 128;
/**
* 生成公私密鑰對
*/
public static Map<String, Object> init()
{
Map<String, Object> map = null;
try
{
KeyPairGenerator generator = KeyPairGenerator.getInstance(KEY_RSA);
//設置密鑰對的bit數,越大越安全,但速度減慢,一般使用512或1024
generator.initialize(1024);
KeyPair keyPair = generator.generateKeyPair();
// 獲取公鑰
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
// 獲取私鑰
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
// 將密鑰對封裝爲Map
map = new HashMap<String, Object>();
map.put(KEY_RSA_PUBLICKEY, publicKey);
map.put(KEY_RSA_PRIVATEKEY, privateKey);
} catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
return map;
}
/**
* 獲取Base64編碼的公鑰字符串
*/
public static String getPublicKey(Map<String, Object> map)
{
String str = "";
Key key = (Key) map.get(KEY_RSA_PUBLICKEY);
str = encryptBase64(key.getEncoded());
return str;
}
/**
* 獲取Base64編碼的私鑰字符串
*/
public static String getPrivateKey(Map<String, Object> map)
{
String str = "";
Key key = (Key) map.get(KEY_RSA_PRIVATEKEY);
str = encryptBase64(key.getEncoded());
return str;
}
/**
* BASE64 解碼
*
* @param key 需要Base64解碼的字符串
* @return 字節數組
*/
public static byte[] decryptBase64(String key)
{
return Base64.getDecoder().decode(key);
}
/**
* BASE64 編碼
*
* @param key 需要Base64編碼的字節數組
* @return 字符串
*/
public static String encryptBase64(byte[] key)
{
return new String(Base64.getEncoder().encode(key));
}
/**
* 公鑰加密
*
* @param encryptingStr
* @param publicKeyStr
* @return
*/
public static String encryptByPublicKey(String encryptingStr, String publicKeyStr)
{
try
{
// 將公鑰由字符串轉爲UTF-8格式的字節數組
byte[] publicKeyBytes = decryptBase64(publicKeyStr);
// 獲得公鑰
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
// 取得待加密數據
byte[] data = encryptingStr.getBytes("UTF-8");
KeyFactory factory;
factory = KeyFactory.getInstance(KEY_RSA);
PublicKey publicKey = factory.generatePublic(keySpec);
// 對數據加密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
// 返回加密後由Base64編碼的加密信息
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對數據分段解密
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[] decryptedData = out.toByteArray();
out.close();
return encryptBase64(decryptedData);
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 私鑰解密
*
* @param encryptedStr
* @param privateKeyStr
* @return
*/
public static String decryptByPrivateKey(String encryptedStr, String privateKeyStr)
{
try
{
// 對私鑰解密
byte[] privateKeyBytes = decryptBase64(privateKeyStr);
// 獲得私鑰
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
// 獲得待解密數據
byte[] data = decryptBase64(encryptedStr);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PrivateKey privateKey = factory.generatePrivate(keySpec);
// 對數據解密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
// 返回UTF-8編碼的解密信息
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對數據分段解密
while (inputLen - offSet > 0)
{
if (inputLen - offSet > MAX_DECRYPT_BLOCK)
{
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
} else
{
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, "UTF-8");
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 私鑰加密
*
* @param encryptingStr
* @param privateKeyStr
* @return
*/
public static String encryptByPrivateKey(String encryptingStr, String privateKeyStr)
{
try
{
byte[] privateKeyBytes = decryptBase64(privateKeyStr);
// 獲得私鑰
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
// 取得待加密數據
byte[] data = encryptingStr.getBytes("UTF-8");
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PrivateKey privateKey = factory.generatePrivate(keySpec);
// 對數據加密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
// 返回加密後由Base64編碼的加密信息
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對數據分段解密
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[] decryptedData = out.toByteArray();
out.close();
return encryptBase64(decryptedData);
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 公鑰解密
*
* @param encryptedStr
* @param publicKeyStr
* @return
*/
public static String decryptByPublicKey(String encryptedStr, String publicKeyStr)
{
try
{
// 對公鑰解密
byte[] publicKeyBytes = decryptBase64(publicKeyStr);
// 取得公鑰
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
// 取得待加密數據
byte[] data = decryptBase64(encryptedStr);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PublicKey publicKey = factory.generatePublic(keySpec);
// 對數據解密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
// 返回UTF-8編碼的解密信息
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對數據分段解密
while (inputLen - offSet > 0)
{
if (inputLen - offSet > MAX_DECRYPT_BLOCK)
{
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
} else
{
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, "UTF-8");
} catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* 用私鑰對加密數據進行簽名
*
* @param encryptedStr
* @param privateKey
* @return
*/
public static String sign(String encryptedStr, String privateKey)
{
String str = "";
try
{
//將私鑰加密數據字符串轉換爲字節數組
byte[] data = encryptedStr.getBytes();
// 解密由base64編碼的私鑰
byte[] bytes = decryptBase64(privateKey);
// 構造PKCS8EncodedKeySpec對象
PKCS8EncodedKeySpec pkcs = new PKCS8EncodedKeySpec(bytes);
// 指定的加密算法
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
// 取私鑰對象
PrivateKey key = factory.generatePrivate(pkcs);
// 用私鑰對信息生成數字簽名
Signature signature = Signature.getInstance(KEY_RSA_SIGNATURE);
signature.initSign(key);
signature.update(data);
str = encryptBase64(signature.sign());
} catch (Exception e)
{
e.printStackTrace();
}
return str;
}
/**
* 校驗數字簽名
*
* @param encryptedStr
* @param publicKey
* @param sign
* @return 校驗成功返回true,失敗返回false
*/
public static boolean verify(String encryptedStr, String publicKey, String sign)
{
boolean flag = false;
try
{
//將私鑰加密數據字符串轉換爲字節數組
byte[] data = encryptedStr.getBytes();
// 解密由base64編碼的公鑰
byte[] bytes = decryptBase64(publicKey);
// 構造X509EncodedKeySpec對象
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(bytes);
// 指定的加密算法
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
// 取公鑰對象
PublicKey key = factory.generatePublic(keySpec);
// 用公鑰驗證數字簽名
Signature signature = Signature.getInstance(KEY_RSA_SIGNATURE);
signature.initVerify(key);
signature.update(data);
flag = signature.verify(decryptBase64(sign));
} catch (Exception e)
{
e.printStackTrace();
}
return flag;
}
}