import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.InvalidParameterException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.Provider;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.util.Date;
import javax.crypto.Cipher;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.DateFormatUtils;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public abstract class RSAUtils {
private static final Logger LOGGER = LoggerFactory.getLogger(RSAUtils.class);
private static final String ALGORITHOM = "RSA";
private static final String RSA_PAIR_FILENAME = "/__RSA_PAIR.txt";
private static final int KEY_SIZE = 1024;
private static final Provider DEFAULT_PROVIDER = new BouncyCastleProvider();
private static KeyPairGenerator keyPairGen = null;
private static KeyFactory keyFactory = null;
private static KeyPair oneKeyPair = null;
private static File rsaPairFile = null;
static {
try {
keyPairGen = KeyPairGenerator.getInstance(ALGORITHOM, DEFAULT_PROVIDER);
keyFactory = KeyFactory.getInstance(ALGORITHOM, DEFAULT_PROVIDER);
} catch (NoSuchAlgorithmException ex) {
LOGGER.error(ex.getMessage());
}
rsaPairFile = new File(getRSAPairFilePath());
}
private RSAUtils() {
}
private static synchronized KeyPair generateKeyPair() {
try {
keyPairGen.initialize(KEY_SIZE, new SecureRandom(DateFormatUtils.format(new Date(), "yyyyMMdd").getBytes()));
oneKeyPair = keyPairGen.generateKeyPair();
saveKeyPair(oneKeyPair);
return oneKeyPair;
} catch (InvalidParameterException ex) {
LOGGER.error("KeyPairGenerator does not support a key length of " + KEY_SIZE + ".", ex);
} catch (NullPointerException ex) {
LOGGER.error("RSAUtils#KEY_PAIR_GEN is null, can not generate KeyPairGenerator instance.", ex);
}
return null;
}
private static String getRSAPairFilePath() {
String urlPath = RSAUtils.class.getResource("/").getPath();
return (new File(urlPath).getParent() + RSA_PAIR_FILENAME);
}
private static boolean isCreateKeyPairFile() {
// 是否创建新的密钥对文件
boolean createNewKeyPair = false;
if (!rsaPairFile.exists() || rsaPairFile.isDirectory()) {
createNewKeyPair = true;
}
return createNewKeyPair;
}
private static void saveKeyPair(KeyPair keyPair) {
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try {
fos = FileUtils.openOutputStream(rsaPairFile);
oos = new ObjectOutputStream(fos);
oos.writeObject(keyPair);
} catch (Exception ex) {
ex.printStackTrace();
} finally {
IOUtils.closeQuietly(oos);
IOUtils.closeQuietly(fos);
}
}
public static KeyPair getKeyPair() {
// 首先判断是否需要重新生成新的密钥对文件
if (isCreateKeyPairFile()) {
// 直接强制生成密钥对文件，并存入缓存。
return generateKeyPair();
}
if (oneKeyPair != null) {
return oneKeyPair;
}
return readKeyPair();
}
// 同步读出保存的密钥对
private static KeyPair readKeyPair() {
FileInputStream fis = null;
ObjectInputStream ois = null;
try {
fis = FileUtils.openInputStream(rsaPairFile);
ois = new ObjectInputStream(fis);
oneKeyPair = (KeyPair) ois.readObject();
return oneKeyPair;
} catch (Exception ex) {
ex.printStackTrace();
} finally {
IOUtils.closeQuietly(ois);
IOUtils.closeQuietly(fis);
}
return null;
}
public static RSAPublicKey generateRSAPublicKey(byte[] modulus, byte[] publicExponent) {
RSAPublicKeySpec publicKeySpec = new RSAPublicKeySpec(new BigInteger(modulus), new BigInteger(publicExponent));
try {
return (RSAPublicKey) keyFactory.generatePublic(publicKeySpec);
} catch (InvalidKeySpecException ex) {
LOGGER.error("RSAPublicKeySpec is unavailable.", ex);
} catch (NullPointerException ex) {
LOGGER.error("RSAUtils#KEY_FACTORY is null, can not generate KeyFactory instance.", ex);
}
return null;
}
public static RSAPrivateKey generateRSAPrivateKey(byte[] modulus, byte[] privateExponent) {
RSAPrivateKeySpec privateKeySpec = new RSAPrivateKeySpec(new BigInteger(modulus), new BigInteger(privateExponent));
try {
return (RSAPrivateKey) keyFactory.generatePrivate(privateKeySpec);
} catch (InvalidKeySpecException ex) {
LOGGER.error("RSAPrivateKeySpec is unavailable.", ex);
} catch (NullPointerException ex) {
LOGGER.error("RSAUtils#KEY_FACTORY is null, can not generate KeyFactory instance.", ex);
}
return null;
}
public static RSAPrivateKey getRSAPrivateKey(String hexModulus, String hexPrivateExponent) {
if (StringUtils.isBlank(hexModulus) || StringUtils.isBlank(hexPrivateExponent)) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("hexModulus and hexPrivateExponent cannot be empty. RSAPrivateKey value is null to return.");
}
return null;
}
byte[] modulus = null;
byte[] privateExponent = null;
try {
modulus = Hex.decodeHex(hexModulus.toCharArray());
privateExponent = Hex.decodeHex(hexPrivateExponent.toCharArray());
} catch (DecoderException ex) {
LOGGER.error("hexModulus or hexPrivateExponent value is invalid. return null(RSAPrivateKey).");
}
if (modulus != null && privateExponent != null) {
return generateRSAPrivateKey(modulus, privateExponent);
}
return null;
}
public static RSAPublicKey getRSAPublidKey(String hexModulus, String hexPublicExponent) {
if (StringUtils.isBlank(hexModulus) || StringUtils.isBlank(hexPublicExponent)) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("hexModulus and hexPublicExponent cannot be empty. return null(RSAPublicKey).");
}
return null;
}
byte[] modulus = null;
byte[] publicExponent = null;
try {
modulus = Hex.decodeHex(hexModulus.toCharArray());
publicExponent = Hex.decodeHex(hexPublicExponent.toCharArray());
} catch (DecoderException ex) {
LOGGER.error("hexModulus or hexPublicExponent value is invalid. return null(RSAPublicKey).");
}
if (modulus != null && publicExponent != null) {
return generateRSAPublicKey(modulus, publicExponent);
}
return null;
}
public static byte[] encrypt(PublicKey publicKey, byte[] data) throws Exception {
Cipher ci = Cipher.getInstance(ALGORITHOM, DEFAULT_PROVIDER);
ci.init(Cipher.ENCRYPT_MODE, publicKey);
return ci.doFinal(data);
}
public static byte[] decrypt(PrivateKey privateKey, byte[] data) throws Exception {
Cipher ci = Cipher.getInstance(ALGORITHOM, DEFAULT_PROVIDER);
ci.init(Cipher.DECRYPT_MODE, privateKey);
return ci.doFinal(data);
}
public static String encryptString(PublicKey publicKey, String plaintext) {
if (publicKey == null || plaintext == null) {
return null;
}
byte[] data = plaintext.getBytes();
try {
byte[] en_data = encrypt(publicKey, data);
return new String(Hex.encodeHex(en_data));
} catch (Exception ex) {
LOGGER.error(ex.getCause().getMessage());
}
return null;
}
public static String encryptString(String plaintext) {
if (plaintext == null) {
return null;
}
byte[] data = plaintext.getBytes();
KeyPair keyPair = getKeyPair();
try {
byte[] en_data = encrypt((RSAPublicKey) keyPair.getPublic(), data);
return new String(Hex.encodeHex(en_data));
} catch (NullPointerException ex) {
LOGGER.error("keyPair cannot be null.");
} catch (Exception ex) {
LOGGER.error(ex.getCause().getMessage());
}
return null;
}
public static String decryptString(PrivateKey privateKey, String encrypttext) {
if (privateKey == null || StringUtils.isBlank(encrypttext)) {
return null;
}
try {
byte[] en_data = Hex.decodeHex(encrypttext.toCharArray());
byte[] data = decrypt(privateKey, en_data);
return new String(data);
} catch (Exception ex) {
LOGGER.error(String.format("\"%s\" Decryption failed. Cause: %s", encrypttext, ex.getCause().getMessage()));
}
return null;
}
public static String decryptString(String encrypttext) {
if (StringUtils.isBlank(encrypttext)) {
return null;
}
KeyPair keyPair = getKeyPair();
try {
byte[] en_data = Hex.decodeHex(encrypttext.toCharArray());
byte[] data = decrypt((RSAPrivateKey) keyPair.getPrivate(), en_data);
return new String(data);
} catch (NullPointerException ex) {
LOGGER.error("keyPair cannot be null.");
} catch (Exception ex) {
LOGGER.error(String.format("\"%s\" Decryption failed. Cause: %s", encrypttext, ex.getMessage()));
}
return null;
}
public static String decryptStringByJs(String encrypttext) {
String text = decryptString(encrypttext);
if (text == null) {
return null;
}
return StringUtils.reverse(text);
}
public static RSAPublicKey getDefaultPublicKey() {
KeyPair keyPair = getKeyPair();
if (keyPair != null) {
return (RSAPublicKey) keyPair.getPublic();
}
return null;
}
public static RSAPrivateKey getDefaultPrivateKey() {
KeyPair keyPair = getKeyPair();
if (keyPair != null) {
return (RSAPrivateKey) keyPair.getPrivate();
}
return null;
}
}