package
com.locator.encryption;
import
java.io.ByteArrayOutputStream;
import
java.security.Key;
import
java.security.KeyFactory;
import
java.security.KeyPair;
import
java.security.KeyPairGenerator;
import
java.security.PrivateKey;
import
java.security.PublicKey;
import
java.security.Signature;
import
java.security.interfaces.RSAPrivateKey;
import
java.security.interfaces.RSAPublicKey;
import
java.security.spec.PKCS8EncodedKeySpec;
import
java.security.spec.X509EncodedKeySpec;
import
java.util.HashMap;
import
java.util.Map;
import
javax.crypto.Cipher;
/**
* <p>
* RSA公钥/私钥/签名工具包
* <p>
* 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/>
* 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/>
* 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全
* </p>
*
*/
public
class
RSAUtils{
/**
* 加密算法RSA
*/
public
static
final
String KEY_ALGORITHM =
"RSA"
;
/**
* 签名算法
*/
public
static
final
String SIGNATURE_ALGORITHM =
"MD5withRSA"
;
/**
* 获取公钥的key
*/
private
static
final
String PUBLIC_KEY =
"LocatorPublicKey"
;
/**
* 获取私钥的key
*/
private
static
final
String PRIVATE_KEY =
"LocatorPrivateKey"
;
/**
* 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
;
/**
* <p>
* 生成密钥对(公钥和私钥)
* </p>
*
* @return
* @throws Exception
*/
public
static
Map<String, Object> genKeyPair()
throws
Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(
1024
);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map<String, Object> keyMap =
new
HashMap<String, Object>(
2
);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return
keyMap;
}
/**
* <p>
* 用私钥对信息生成数字签名
* </p>
*
* @param data 已加密数据
* @param privateKey 私钥(BASE64编码)
*
* @return
* @throws Exception
*/
public
static
String sign(
byte
[] data, String privateKey)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec =
new
PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return
Base64Utils.encode(signature.sign());
}
/**
* <p>
* 校验数字签名
* </p>
*
* @param data 已加密数据
* @param publicKey 公钥(BASE64编码)
* @param sign 数字签名
*
* @return
* @throws Exception
*
*/
public
static
boolean
verify(
byte
[] data, String publicKey, String sign)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec keySpec =
new
X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data);
return
signature.verify(Base64Utils.decode(sign));
}
/**
* <P>
* 私钥解密
* </p>
*
* @param encryptedData 已加密数据
* @param privateKey 私钥(BASE64编码)
* @return
* @throws Exception
*/
public
static
byte
[] decryptByPrivateKey(
byte
[] encryptedData, String privateKey)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec =
new
PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int
inputLen = encryptedData.length;
ByteArrayOutputStream out =
new
ByteArrayOutputStream();
int
offSet =
0
;
byte
[] cache;
int
i =
0
;
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
decryptedData;
}
/**
* <p>
* 公钥解密
* </p>
*
* @param encryptedData 已加密数据
* @param publicKey 公钥(BASE64编码)
* @return
* @throws Exception
*/
public
static
byte
[] decryptByPublicKey(
byte
[] encryptedData, String publicKey)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec =
new
X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int
inputLen = encryptedData.length;
ByteArrayOutputStream out =
new
ByteArrayOutputStream();
int
offSet =
0
;
byte
[] cache;
int
i =
0
;
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
decryptedData;
}
/**
* <p>
* 公钥加密
* </p>
*
* @param data 源数据
* @param publicKey 公钥(BASE64编码)
* @return
* @throws Exception
*/
public
static
byte
[] encryptByPublicKey(
byte
[] data, String publicKey)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec =
new
X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int
inputLen = data.length;
ByteArrayOutputStream out =
new
ByteArrayOutputStream();
int
offSet =
0
;
byte
[] cache;
int
i =
0
;
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
[] encryptedData = out.toByteArray();
out.close();
return
encryptedData;
}
/**
* <p>
* 私钥加密
* </p>
*
* @param data 源数据
* @param privateKey 私钥(BASE64编码)
* @return
* @throws Exception
*/
public
static
byte
[] encryptByPrivateKey(
byte
[] data, String privateKey)
throws
Exception {
byte
[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec =
new
PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int
inputLen = data.length;
ByteArrayOutputStream out =
new
ByteArrayOutputStream();
int
offSet =
0
;
byte
[] cache;
int
i =
0
;
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
[] encryptedData = out.toByteArray();
out.close();
return
encryptedData;
}
/**
* <p>
* 获取私钥
* </p>
*
* @param keyMap 密钥对
* @return
* @throws Exception
*/
public
static
String getPrivateKey(Map<String, Object> keyMap)
throws
Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return
Base64Utils.encode(key.getEncoded());
}
/**
* <p>
* 获取公钥
* </p>
*
* @param keyMap 密钥对
* @return
* @throws Exception
*/
public
static
String getPublicKey(Map<String, Object> keyMap)
throws
Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return
Base64Utils.encode(key.getEncoded());
}
}