由于項目中要傳輸和保存敏感數(shù)據(jù),，于是寫了一個RSA進行加密解密的工具類.大家如有需要,可以參考下.

加密和解密的代碼如下:

public class RSAEncrypt {

/**

* 字節(jié)數(shù)據(jù)轉(zhuǎn)字符串專用集合

*/

private static final char[] HEX_CHAR = { '0', '1', '2', '3', '4', '5', '6',

'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

/**

* 隨機生成密鑰對

*/

public static void genKeyPair(String filePath) {

// KeyPairGenerator類用于生成公鑰和私鑰對,，基于RSA算法生成對象

KeyPairGenerator keyPairGen = null;

try {

keyPairGen = KeyPairGenerator.getInstance('RSA');

} catch (NoSuchAlgorithmException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

// 初始化密鑰對生成器,，密鑰大小為96-1024位

keyPairGen.initialize(1024,new SecureRandom());

// 生成一個密鑰對,，保存在keyPair中

KeyPair keyPair = keyPairGen.generateKeyPair();

// 得到私鑰

RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

// 得到公鑰

RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

try {

// 得到公鑰字符串

String publicKeyString = Base64.encode(publicKey.getEncoded());

// 得到私鑰字符串

String privateKeyString = Base64.encode(privateKey.getEncoded());

// 將密鑰對寫入到文件

FileWriter pubfw = new FileWriter(filePath + '/publicKey.keystore');

FileWriter prifw = new FileWriter(filePath + '/privateKey.keystore');

BufferedWriter pubbw = new BufferedWriter(pubfw);

BufferedWriter pribw = new BufferedWriter(prifw);

pubbw.write(publicKeyString);

pribw.write(privateKeyString);

pubbw.flush();

pubbw.close();

pubfw.close();

pribw.flush();

pribw.close();

prifw.close();

} catch (Exception e) {

e.printStackTrace();

}

}

/**

* 從文件中輸入流中加載公鑰

*

* @param in

* 公鑰輸入流

* @throws Exception

* 加載公鑰時產(chǎn)生的異常

*/

public static String loadPublicKeyByFile(String path) throws Exception {

try {

BufferedReader br = new BufferedReader(new FileReader(path

+ '/publicKey.keystore'));

String readLine = null;

StringBuilder sb = new StringBuilder();

while ((readLine = br.readLine()) != null) {

sb.append(readLine);

}

br.close();

return sb.toString();

} catch (IOException e) {

throw new Exception('公鑰數(shù)據(jù)流讀取錯誤');

} catch (NullPointerException e) {

throw new Exception('公鑰輸入流為空');

}

}

/**

* 從字符串中加載公鑰

*

* @param publicKeyStr

* 公鑰數(shù)據(jù)字符串

* @throws Exception

* 加載公鑰時產(chǎn)生的異常

*/

public static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)

throws Exception {

try {

byte[] buffer = Base64.decode(publicKeyStr);

KeyFactory keyFactory = KeyFactory.getInstance('RSA');

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);

return (RSAPublicKey) keyFactory.generatePublic(keySpec);

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此算法');

} catch (InvalidKeySpecException e) {

throw new Exception('公鑰非法');

} catch (NullPointerException e) {

throw new Exception('公鑰數(shù)據(jù)為空');

}

}

/**

* 從文件中加載私鑰

*

* @param keyFileName

* 私鑰文件名

* @return 是否成功

* @throws Exception

*/

public static String loadPrivateKeyByFile(String path) throws Exception {

try {

BufferedReader br = new BufferedReader(new FileReader(path

+ '/privateKey.keystore'));

String readLine = null;

StringBuilder sb = new StringBuilder();

while ((readLine = br.readLine()) != null) {

sb.append(readLine);

}

br.close();

return sb.toString();

} catch (IOException e) {

throw new Exception('私鑰數(shù)據(jù)讀取錯誤');

} catch (NullPointerException e) {

throw new Exception('私鑰輸入流為空');

}

}

public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)

throws Exception {

try {

byte[] buffer = Base64.decode(privateKeyStr);

PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);

KeyFactory keyFactory = KeyFactory.getInstance('RSA');

return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此算法');

} catch (InvalidKeySpecException e) {

throw new Exception('私鑰非法');

} catch (NullPointerException e) {

throw new Exception('私鑰數(shù)據(jù)為空');

}

}

/**

* 公鑰加密過程

*

* @param publicKey

* 公鑰

* @param plainTextData

* 明文數(shù)據(jù)

* @return

* @throws Exception

* 加密過程中的異常信息

*/

public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)

throws Exception {

if (publicKey == null) {

throw new Exception('加密公鑰為空, 請設(shè)置');

}

Cipher cipher = null;

try {

// 使用默認RSA

cipher = Cipher.getInstance('RSA');

// cipher= Cipher.getInstance('RSA', new BouncyCastleProvider());

cipher.init(Cipher.ENCRYPT_MODE, publicKey);

byte[] output = cipher.doFinal(plainTextData);

return output;

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此加密算法');

} catch (NoSuchPaddingException e) {

e.printStackTrace();

return null;

} catch (InvalidKeyException e) {

throw new Exception('加密公鑰非法,請檢查');

} catch (IllegalBlockSizeException e) {

throw new Exception('明文長度非法');

} catch (BadPaddingException e) {

throw new Exception('明文數(shù)據(jù)已損壞');

}

}

/**

* 私鑰加密過程

*

* @param privateKey

* 私鑰

* @param plainTextData

* 明文數(shù)據(jù)

* @return

* @throws Exception

* 加密過程中的異常信息

*/

public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)

throws Exception {

if (privateKey == null) {

throw new Exception('加密私鑰為空, 請設(shè)置');

}

Cipher cipher = null;

try {

// 使用默認RSA

cipher = Cipher.getInstance('RSA');

cipher.init(Cipher.ENCRYPT_MODE, privateKey);

byte[] output = cipher.doFinal(plainTextData);

return output;

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此加密算法');

} catch (NoSuchPaddingException e) {

e.printStackTrace();

return null;

} catch (InvalidKeyException e) {

throw new Exception('加密私鑰非法,請檢查');

} catch (IllegalBlockSizeException e) {

throw new Exception('明文長度非法');

} catch (BadPaddingException e) {

throw new Exception('明文數(shù)據(jù)已損壞');

}

}

/**

* 私鑰解密過程

*

* @param privateKey

* 私鑰

* @param cipherData

* 密文數(shù)據(jù)

* @return 明文

* @throws Exception

* 解密過程中的異常信息

*/

public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)

throws Exception {

if (privateKey == null) {

throw new Exception('解密私鑰為空, 請設(shè)置');

}

Cipher cipher = null;

try {

// 使用默認RSA

cipher = Cipher.getInstance('RSA');

// cipher= Cipher.getInstance('RSA', new BouncyCastleProvider());

cipher.init(Cipher.DECRYPT_MODE, privateKey);

byte[] output = cipher.doFinal(cipherData);

return output;

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此解密算法');

} catch (NoSuchPaddingException e) {

e.printStackTrace();

return null;

} catch (InvalidKeyException e) {

throw new Exception('解密私鑰非法,請檢查');

} catch (IllegalBlockSizeException e) {

throw new Exception('密文長度非法');

} catch (BadPaddingException e) {

throw new Exception('密文數(shù)據(jù)已損壞');

}

}

/**

* 公鑰解密過程

*

* @param publicKey

* 公鑰

* @param cipherData

* 密文數(shù)據(jù)

* @return 明文

* @throws Exception

* 解密過程中的異常信息

*/

public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)

throws Exception {

if (publicKey == null) {

throw new Exception('解密公鑰為空, 請設(shè)置');

}

Cipher cipher = null;

try {

// 使用默認RSA

cipher = Cipher.getInstance('RSA');

// cipher= Cipher.getInstance('RSA', new BouncyCastleProvider());

cipher.init(Cipher.DECRYPT_MODE, publicKey);

byte[] output = cipher.doFinal(cipherData);

return output;

} catch (NoSuchAlgorithmException e) {

throw new Exception('無此解密算法');

} catch (NoSuchPaddingException e) {

e.printStackTrace();

return null;

} catch (InvalidKeyException e) {

throw new Exception('解密公鑰非法,請檢查');

} catch (IllegalBlockSizeException e) {

throw new Exception('密文長度非法');

} catch (BadPaddingException e) {

throw new Exception('密文數(shù)據(jù)已損壞');

}

}

/**

* 字節(jié)數(shù)據(jù)轉(zhuǎn)十六進制字符串

*

* @param data

* 輸入數(shù)據(jù)

* @return 十六進制內(nèi)容

*/

public static String byteArrayToString(byte[] data) {

StringBuilder stringBuilder = new StringBuilder();

for (int i = 0; i < data.length; i++) {

// 取出字節(jié)的高四位 作為索引得到相應(yīng)的十六進制標(biāo)識符 注意無符號右移

stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);

// 取出字節(jié)的低四位 作為索引得到相應(yīng)的十六進制標(biāo)識符

stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);

if (i < data.length - 1) {

stringBuilder.append(' ');

}

}

return stringBuilder.toString();

}

}

簽名及校驗的代碼如下:

public class RSASignature{

/**

* 簽名算法

*/

public static final String SIGN_ALGORITHMS = 'SHA1WithRSA';

/**

* RSA簽名

* @param content 待簽名數(shù)據(jù)

* @param privateKey 商戶私鑰

* @param encode 字符集編碼

* @return 簽名值

*/

public static String sign(String content, String privateKey, String encode)

{

try

{

PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec( Base64.decode(privateKey) );

KeyFactory keyf = KeyFactory.getInstance('RSA');

PrivateKey priKey = keyf.generatePrivate(priPKCS8);

java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

signature.initSign(priKey);

signature.update( content.getBytes(encode));

byte[] signed = signature.sign();

return Base64.encode(signed);

}

catch (Exception e)

{

e.printStackTrace();

}

return null;

}

public static String sign(String content, String privateKey)

{

try

{

PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec( Base64.decode(privateKey) );

KeyFactory keyf = KeyFactory.getInstance('RSA');

PrivateKey priKey = keyf.generatePrivate(priPKCS8);

java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

signature.initSign(priKey);

signature.update( content.getBytes());

byte[] signed = signature.sign();

return Base64.encode(signed);

}

catch (Exception e)

{

e.printStackTrace();

}

return null;

}

/**

* RSA驗簽名檢查

* @param content 待簽名數(shù)據(jù)

* @param sign 簽名值

* @param publicKey 分配給開發(fā)商公鑰

* @param encode 字符集編碼

* @return 布爾值

*/

public static boolean doCheck(String content, String sign, String publicKey,String encode)

{

try

{

KeyFactory keyFactory = KeyFactory.getInstance('RSA');

byte[] encodedKey = Base64.decode(publicKey);

PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

java.security.Signature signature = java.security.Signature

.getInstance(SIGN_ALGORITHMS);

signature.initVerify(pubKey);

signature.update( content.getBytes(encode) );

boolean bverify = signature.verify( Base64.decode(sign) );

return bverify;

}

catch (Exception e)

{

e.printStackTrace();

}

return false;

}

public static boolean doCheck(String content, String sign, String publicKey)

{

try

{

KeyFactory keyFactory = KeyFactory.getInstance('RSA');

byte[] encodedKey = Base64.decode(publicKey);

PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

java.security.Signature signature = java.security.Signature

.getInstance(SIGN_ALGORITHMS);

signature.initVerify(pubKey);

signature.update( content.getBytes() );

boolean bverify = signature.verify( Base64.decode(sign) );

return bverify;

}

catch (Exception e)

{

e.printStackTrace();

}

return false;

}

}

測試代碼如下(需要添加commons-codec.jar依賴):

public class MainTest {

public static void main(String[] args) throws Exception {

String filepath='d:/rsa/';

System.out.println('--------------公鑰加密私鑰解密過程-------------------');

String plainText='ihep_公鑰加密私鑰解密';

//公鑰加密過程

byte[] cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)),plainText.getBytes());

String cipher=Base64.encode(cipherData);

//私鑰解密過程

byte[] res=RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)), Base64.decode(cipher));

String restr=new String(res);

System.out.println('原文：'+plainText);

System.out.println('加密：'+cipher);

System.out.println('解密：'+restr);

System.out.println();

System.out.println('--------------私鑰加密公鑰解密過程-------------------');

plainText='ihep_私鑰加密公鑰解密';

//私鑰加密過程

cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)),plainText.getBytes());

cipher=Base64.encode(cipherData);

//公鑰解密過程

res=RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), Base64.decode(cipher));

restr=new String(res);

System.out.println('原文：'+plainText);

System.out.println('加密：'+cipher);

System.out.println('解密：'+restr);

System.out.println();

System.out.println('---------------私鑰簽名過程------------------');

String content='ihep_這是用于簽名的原始數(shù)據(jù)';

String signstr=RSASignature.sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath));

System.out.println('簽名原串：'+content);

System.out.println('簽名串：'+signstr);

System.out.println();

System.out.println('---------------公鑰校驗簽名------------------');

System.out.println('簽名原串：'+content);

System.out.println('簽名串：'+signstr);

System.out.println('驗簽結(jié)果：'+RSASignature.doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));

System.out.println();

}

}

該工具類代碼,可以結(jié)合MD5等算法混合使用,實現(xiàn)多重加密效果,有效保護數(shù)據(jù)安全