非對稱加密演算法RSA工具
阿新 • • 發佈:2018-11-27
非對稱加密演算法RSA工具
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security. spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import org.bouncycastle.util.encoders.Base64;
public class RSAUtil {
/**
* RSA演算法
*/
private static final String KEY_ALGORITHM = "RSA";
/**
* 數字簽名
*/
private static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
public static String[] createKeys() {
try {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
// 公鑰
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
// 私鑰
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
String[] res = new String[2];
res[0] = byteArrayToBase64Str(publicKey.getEncoded());
res[1] = byteArrayToBase64Str(privateKey.getEncoded());
return res;
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
private static byte[] base64StrToByteArray(String data) {
return Base64.decode(data.getBytes());
}
private static String byteArrayToBase64Str(byte[] data) {
return Base64.toBase64String(data);
}
/**
* 數字簽名
*
* @param data 要簽名的密文
* @param privateKey 私鑰
* @return 返回簽名信息
*/
public static String RSASign(String data, String privateKey) {
try {
// 解密由base64編碼的私鑰
byte[] keyBytes = base64StrToByteArray(privateKey);
// 構造PKCS8EncodedKeySpec物件
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密演算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取私鑰匙物件
PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 用私鑰對資訊生成數字簽名
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(priKey);
signature.update(base64StrToByteArray(data));
return byteArrayToBase64Str(signature.sign());
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (SignatureException e) {
e.printStackTrace();
}
return null;
}
/**
* 驗證簽名
*
* @param data 要驗證的密文
* @param publicKey 公鑰
* @param sign 簽名信息
* @return 返回驗證成功狀態
*/
public static boolean RSAVerify(String data, String publicKey, String sign) {
try {
// 解密由base64編碼的公鑰
byte[] keyBytes = base64StrToByteArray(publicKey);
// 構造X509EncodedKeySpec物件
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密演算法
Signature signature;
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取公鑰匙物件
PublicKey pubKey = keyFactory.generatePublic(keySpec);
signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(pubKey);
signature.update(base64StrToByteArray(data));
// 驗證簽名是否正常
return signature.verify(base64StrToByteArray(sign));
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (SignatureException e) {
e.printStackTrace();
}
return false;
}
/**
* 私鑰解密
*
* @param data 要解密的字串
* @param key 私鑰
* @return 返回解密後的字串
*/
public static String RSADecryptByPrivateKey(String data, String key) {
try {
// 對金鑰解密
byte[] keyBytes = base64StrToByteArray(key);
// 取得私鑰
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 對資料解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] encryptedData = base64StrToByteArray(data);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對資料分段解密
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 new String(decryptedData);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* 公鑰解密
*
* @param data 要解密的資料
* @param key 公鑰
* @return 返回解密後的資料
*/
public static String RSADecryptByPublicKey(String data, String key) {
try {
// 對金鑰解密
byte[] keyBytes = base64StrToByteArray(key);
// 取得公鑰
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicKey = keyFactory.generatePublic(x509KeySpec);
// 對資料解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
byte[] encryptedData = base64StrToByteArray(data);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對資料分段解密
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 new String(decryptedData);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* 公鑰加密
*
* @param data 要加密的資料
* @param key 公鑰
* @return 返回加密的資料
*/
public static String RSAEncryptByPublicKey(String data, String key) {
try {
// 對公鑰解密
byte[] keyBytes = base64StrToByteArray(key);
// 取得公鑰
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicKey = keyFactory.generatePublic(x509KeySpec);
// 對資料加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] decryptedData = data.getBytes();
int inputLen = decryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對資料分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(decryptedData, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(decryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return byteArrayToBase64Str(encryptedData);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* 私鑰加密
*
* @param data 要加密的資料
* @param key 私鑰
* @return 返回加密後的資料
*/
public static String RSAEncryptByPrivateKey(String data, String key) {
try {
// 對金鑰解密
byte[] keyBytes = base64StrToByteArray(key);
// 取得私鑰
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 對資料加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
byte[] decryptedData = data.getBytes();
int inputLen = decryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 對資料分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(decryptedData, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(decryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return byteArrayToBase64Str(encryptedData);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace