import javax.crypto.Cipher;
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;
/**
* 非對稱加密RSA算法工具類
*/
public class RSACoder {
//非對稱密鑰算法
public static final String KEY_ALGORITHM = "RSA";
/**
* RSA密鑰長度必須是64的倍數，在512~65536之間。預設是1024
*/
public static final int KEY_SIZE = 2048;
//公鑰
private static final String PUBLIC_KEY = "publicKey";
//私鑰
private static final String PRIVATE_KEY = "privateKey";
/**
* 初始化密鑰對
*
* @return Map 甲方密鑰的Map
*/
public static Map<String, Object> initKey() throws Exception {
//執行個體化密鑰生成器
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM);
//初始化密鑰生成器
keyPairGenerator.initialize(KEY_SIZE);
// 生成一個密鑰對，儲存在keyPair中
KeyPair keyPair = keyPairGenerator.generateKeyPair();
//甲方公鑰
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
System.out.println("系數：" + publicKey.getModulus() + " 加密指數：" + publicKey.getPublicExponent());
//甲方私鑰
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
System.out.println("系數：" + privateKey.getModulus() + "解密指數：" + privateKey.getPrivateExponent());
//将密鑰存儲在map中
Map<String, Object> keyMap = new HashMap<String, Object>();
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
* 公鑰加密
*
* @param data 待加密資料
* @param key 密鑰
* @return byte[] 加密資料
*/
public static byte[] encryptByPublicKey(byte[] data, byte[] key) throws Exception {
//執行個體化密鑰工廠
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//初始化公鑰
//密鑰材料轉換
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);
//産生公鑰
PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);
//資料加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
return cipher.doFinal(data);
}
/**
* 私鑰解密
*
* @param data 待解密資料
* @param key 密鑰
* @return byte[] 解密資料
*/
public static byte[] decryptByPrivateKey(byte[] data, byte[] key) throws Exception {
//取得私鑰
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//生成私鑰
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
//資料解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
return cipher.doFinal(data);
}
/**
* 私鑰加密
*
* @param data 待加密資料
* @param key 密鑰
* @return byte[] 加密資料
*/
public static byte[] encryptByPrivateKey(byte[] data, byte[] key) throws Exception {
//取得私鑰
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//生成私鑰
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
//資料加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
return cipher.doFinal(data);
}
/**
* 公鑰解密
*
* @param data 待解密資料
* @param key 密鑰
* @return byte[] 解密資料
*/
public static byte[] decryptByPublicKey(byte[] data, byte[] key) throws Exception {
//執行個體化密鑰工廠
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//初始化公鑰
//密鑰材料轉換
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);
//産生公鑰
PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);
//資料解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, pubKey);
return cipher.doFinal(data);
}
/**
* 取得私鑰
*
* @param keyMap 密鑰map
* @return byte[] 私鑰
*/
public static byte[] getPrivateKey(Map<String, Object> keyMap) {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return key.getEncoded();
}
/**
* 取得公鑰
*
* @param keyMap 密鑰map
* @return byte[] 公鑰
*/
public static byte[] getPublicKey(Map<String, Object> keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return key.getEncoded();
}
/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
//初始化密鑰
//生成密鑰對
Map<String, Object> keyMap = RSACoder.initKey();
//公鑰
byte[] publicKey = RSACoder.getPublicKey(keyMap);
System.out.println("\n公鑰:" + Base64.getEncoder().withoutPadding().encodeToString(publicKey));//由于加密後的密文都是位元組碼形式的，我們要以字元串方式儲存或傳輸的話，可以使用Base64編碼。
//私鑰
byte[] privateKey = RSACoder.getPrivateKey(keyMap);
System.out.println("\n私鑰:" + Base64.getEncoder().withoutPadding().encodeToString(privateKey));//由于加密後的密文都是位元組碼形式的，我們要以字元串方式儲存或傳輸的話，可以使用Base64編碼。
System.out.println("\n===========1.公鑰加密,私鑰解密==============");
String str = "aattaggcctegthththfef/aat.mp4";
System.out.println("原文:" + str);
//使用公鑰進行資料的加密
byte[] code1 = RSACoder.encryptByPublicKey(str.getBytes(), publicKey);
System.out.println("公鑰加密後的資料：" + Base64.getEncoder().withoutPadding().encodeToString(code1));
//使用私鑰進行資料的解密
byte[] decode1 = RSACoder.decryptByPrivateKey(code1, privateKey);
System.out.println("私鑰解密後的資料：" + new String(decode1));
System.out.println("\n===========2.反向進行操作,私鑰加密,公鑰解密==============");
str ="4b9d373bed9f40b389f0e42ebaf729b4";
System.out.println("原文:" + str);
//使用私鑰進行資料的加密
byte[] code2 = RSACoder.encryptByPrivateKey(str.getBytes(), privateKey);
System.out.println("私鑰加密後的資料：" +Base64.getEncoder().withoutPadding().encodeToString(code2));
//使用公鑰進行資料的解密
byte[] decode2 = RSACoder.decryptByPublicKey(code2, publicKey);
System.out.println("公鑰解密後的資料：" + new String(decode2));
}
}
main方法執行結果
系數：25673086491181252696735907678323359012290479118460249182240942943781022994992575396590727636402349564925636011579483415535025350805322419881144350331454228457159864635273352797075670117225640053564150779878581672826043466730442466562220815297498994632148250863062496794801485613090601179615469513565622072320713419491283100791224145056532853893350394503766393820017518906472919715328843855105481040100067458333759790298618468832658166599809135248953553073655427587148287992213804301398790107769457487285016468303621342838245142810915126734720967207513720464121646170199288480519720222247070607912244425592472384699833 加密指數：65537
系數：25673086491181252696735907678323359012290479118460249182240942943781022994992575396590727636402349564925636011579483415535025350805322419881144350331454228457159864635273352797075670117225640053564150779878581672826043466730442466562220815297498994632148250863062496794801485613090601179615469513565622072320713419491283100791224145056532853893350394503766393820017518906472919715328843855105481040100067458333759790298618468832658166599809135248953553073655427587148287992213804301398790107769457487285016468303621342838245142810915126734720967207513720464121646170199288480519720222247070607912244425592472384699833解密指數：5951226482353870194986220142043249921642994930613975396746943027632044514395337067992223236526305668406400388908792163950258710795954318977590444637921367147125633818134378682166922203043958736190954402061666124076067753277825990692483003890925808725629739339787378905147079808872429514941456167509787303701594458366179085655994722382066825611874856877831944821823855957870861590255730073317554239720440140157947209450604893997531142179043822700188495148788044375693219726672614185030409346413260290559526517250002718058539432864497234239894526319410363940220217629293027556378044752569803302642220451834422341413473
公鑰:MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAy165kj4sGDx2rtzHZmTrA++C7LiCX8j7J0OI0MwnLSDp1lNaVsrBU0u1UNHuaKAXzAvDZI8U1rm6cHfh9AhCePNTY2JwCTwf/Xnj1/S7OreIpxxaGuRbnVwCcFbDQ/S8JSpD4bYe5LrkKk1WW15tA6ZaLq1gcbfgRw3ZCB5wkqI4T7jrapS2uNpeGYKdXYRCwArlPSTr3UB33IKA4DXVzE0Gop97GJ4lT+HeewfBUQ7rkIOMka85NL+yi0yB34kHX4uqaySMWe4edNXGJDC1lRxCYTo7QBPBSqS5ibeHpn8Z3RRiYpWRv0UkC75FUyN3yudUhBDAKoOdIuiF2+H9uQIDAQAB
私鑰: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
===========1.公鑰加密,私鑰解密==============
原文:aattaggcctegthththfef/aat.mp4
公鑰加密後的資料：EfjUSb8my/YWrzOziQYKGuB9KbJeZO6uZSRsRZgaEu1m5zHujZ+FA9QK1abjn/ELgCmQw5B91BGFZia2ySbtMLe3n0bD32udI0ufeLA5n/uPEyuiKdrPQcgN22ugJXcrNL9Hbd6WbYbXzeraTK03k61yM2KmgfW/usjbGMjxJ+zoHtw6zHg6lX3O5QrHlx1Q/GUWI61gn4Lp3TsqlRg0YG5/BAOFsRSSdQibK2h2BHxwsiivTidbSc7Z7eSrWPC6T/j0PCgYjsW6O9lRKNdtSlMC6S3Nh9723i0MkqgcE0g8/QV0DxetSbvkFibvaNgh059KLsE0JWyIvINY6bDYFw
私鑰解密後的資料：aattaggcctegthththfef/aat.mp4
===========2.反向進行操作,私鑰加密,公鑰解密==============
原文:4b9d373bed9f40b389f0e42ebaf729b4
私鑰加密後的資料：mQr+BUTDHakOJsUqt+g4UHeUC+pGBM6YjZmMcTFXT3mJw4EcbBdh1UF+R1rWCJc7l2ofsnWMnwosWCPuPJTN8LI2PYNICeXHOLCOWZ2DKz6ARdpZuebpPfnLJ0D5dK1oh/8ndgUiN/SBDaGgIK//3MQp2yRn+O+d3Xv193T2i7vRx/oDyI3/F0Ftbwj3L8RtSPIYv3Zf7c69xTsiYkwGZ3UWCLcEwaLD9d2k60VX2CQntWhJ5mTYHYdjA7z57oMz0hEx7WdUFMM+RLkhOIo8hljY3RjhwDN1BLru6wFfQ5ztnZ6kDaaJRKEdfzjePxZ4MQqI4hgHtHC1NrYV3ZIM0w
公鑰解密後的資料：4b9d373bed9f40b389f0e42ebaf729b4
![加密解密-簽名驗簽-學習[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)