package security;
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公鑰/私鑰/簽名工具包
* </p>
* <p>
* 羅納德·李維斯特(Ron [R]ivest)、阿迪·薩莫爾(Adi [S]hamir)和倫納德·阿德曼(Leonard [A]dleman)
* </p>
* <p>
* 字符串格式的密鑰在未在特殊說明情況下都爲BASE64編碼格式<br/>
* 由於非對稱加密速度極其緩慢,一般文件不使用它來加密而是使用對稱加密,<br/>
* 非對稱加密算法可以用來對對稱加密的密鑰加密,這樣保證密鑰的安全也就保證了數據的安全
* </p>
*
* @author IceWee
* @date 2012-4-26
* @version 1.0
*/
public class RSAUtils {
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";
/**
* 簽名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* 獲取公鑰的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
/**
* 獲取私鑰的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/**
* 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>
* 生成密鑰對(公鑰和私鑰)
* </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>
* 用私鑰對信息生成數字簽名
* </p>
*
* @param data 已加密數據
* @param privateKey 私鑰(BASE64編碼)
*
* @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>
* 校驗數字簽名
* </p>
*
* @param data 已加密數據
* @param publicKey 公鑰(BASE64編碼)
* @param sign 數字簽名
*
* @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>
* 私鑰解密
* </p>
*
* @param encryptedData 已加密數據
* @param privateKey 私鑰(BASE64編碼)
* @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;
// 對數據分段解密
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 decryptedData;
}
/**
* <p>
* 公鑰解密
* </p>
*
* @param encryptedData 已加密數據
* @param publicKey 公鑰(BASE64編碼)
* @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;
// 對數據分段解密
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 decryptedData;
}
/**
* <p>
* 公鑰加密
* </p>
*
* @param data 源數據
* @param publicKey 公鑰(BASE64編碼)
* @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);
// 對數據加密
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;
// 對數據分段加密
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>
* 私鑰加密
* </p>
*
* @param data 源數據
* @param privateKey 私鑰(BASE64編碼)
* @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;
// 對數據分段加密
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>
* 獲取私鑰
* </p>
*
* @param keyMap 密鑰對
* @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>
* 獲取公鑰
* </p>
*
* @param keyMap 密鑰對
* @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());
}
}
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import it.sauronsoftware.base64.Base64;
/**
* <p>
* BASE64編碼解碼工具包
* </p>
* <p>
* 依賴javabase64-1.3.1.jar
* </p>
*
* @author IceWee
* @date 2012-5-19
* @version 1.0
*/
public class Base64Utils {
/**
* 文件讀取緩衝區大小
*/
private static final int CACHE_SIZE = 1024;
/**
* <p>
* BASE64字符串解碼爲二進制數據
* </p>
*
* @param base64
* @return
* @throws Exception
*/
public static byte[] decode(String base64) throws Exception {
return Base64.decode(base64.getBytes());
}
/**
* <p>
* 二進制數據編碼爲BASE64字符串
* </p>
*
* @param bytes
* @return
* @throws Exception
*/
public static String encode(byte[] bytes) throws Exception {
return new String(Base64.encode(bytes));
}
/**
* <p>
* 將文件編碼爲BASE64字符串
* </p>
* <p>
* 大文件慎用,可能會導致內存溢出
* </p>
*
* @param filePath 文件絕對路徑
* @return
* @throws Exception
*/
public static String encodeFile(String filePath) throws Exception {
byte[] bytes = fileToByte(filePath);
return encode(bytes);
}
/**
* <p>
* BASE64字符串轉回文件
* </p>
*
* @param filePath 文件絕對路徑
* @param base64 編碼字符串
* @throws Exception
*/
public static void decodeToFile(String filePath, String base64) throws Exception {
byte[] bytes = decode(base64);
byteArrayToFile(bytes, filePath);
}
/**
* <p>
* 文件轉換爲二進制數組
* </p>
*
* @param filePath 文件路徑
* @return
* @throws Exception
*/
public static byte[] fileToByte(String filePath) throws Exception {
byte[] data = new byte[0];
File file = new File(filePath);
if (file.exists()) {
FileInputStream in = new FileInputStream(file);
ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
data = out.toByteArray();
}
return data;
}
/**
* <p>
* 二進制數據寫文件
* </p>
*
* @param bytes 二進制數據
* @param filePath 文件生成目錄
*/
public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {
InputStream in = new ByteArrayInputStream(bytes);
File destFile = new File(filePath);
if (!destFile.getParentFile().exists()) {
destFile.getParentFile().mkdirs();
}
destFile.createNewFile();
OutputStream out = new FileOutputStream(destFile);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
}
}
import java.util.Map;
public class RSATester {
static String publicKey;
static String privateKey;
static {
try {
Map<String, Object> keyMap = RSAUtils.genKeyPair();
publicKey = RSAUtils.getPublicKey(keyMap);
privateKey = RSAUtils.getPrivateKey(keyMap);
System.err.println("公鑰: \n\r" + publicKey);
System.err.println("私鑰: \n\r" + privateKey);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
test();
testSign();
}
static void test() throws Exception {
System.err.println("公鑰加密——私鑰解密");
String source = "這是一行沒有任何意義的文字,你看完了等於沒看,不是嗎?";
System.out.println("\r加密前文字:\r\n" + source);
byte[] data = source.getBytes();
byte[] encodedData = RSAUtils.encryptByPublicKey(data, publicKey);
System.out.println("加密後文字:\r\n" + new String(encodedData));
byte[] decodedData = RSAUtils.decryptByPrivateKey(encodedData, privateKey);
String target = new String(decodedData);
System.out.println("解密後文字: \r\n" + target);
}
static void testSign() throws Exception {
System.err.println("私鑰加密——公鑰解密");
String source = "這是一行測試RSA數字簽名的無意義文字";
System.out.println("原文字:\r\n" + source);
byte[] data = source.getBytes();
byte[] encodedData = RSAUtils.encryptByPrivateKey(data, privateKey);
System.out.println("加密後:\r\n" + new String(encodedData));
byte[] decodedData = RSAUtils.decryptByPublicKey(encodedData, publicKey);
String target = new String(decodedData);
System.out.println("解密後: \r\n" + target);
System.err.println("私鑰簽名——公鑰驗證簽名");
String sign = RSAUtils.sign(encodedData, privateKey);
System.err.println("簽名:\r" + sign);
boolean status = RSAUtils.verify(encodedData, publicKey, sign);
System.err.println("驗證結果:\r" + status);
}
}
字節與字符串之間轉換方法(hex):
/**
* 將byte數組轉換爲表示16進制值的字符串, 如:byte[]{8,18}轉換爲:0813, 和public static byte[]
* hexStr2ByteArr(String strIn) 互爲可逆的轉換過程
*
* @param arrB
* 需要轉換的byte數組
* @return 轉換後的字符串
* @throws Exception
* 本方法不處理任何異常,所有異常全部拋出
*/
public static String byteArr2HexStr(byte[] arrB) throws Exception {
int iLen = arrB.length;
// 每個byte用兩個字符才能表示,所以字符串的長度是數組長度的兩倍
StringBuffer sb = new StringBuffer(iLen * 2);
for (int i = 0; i < iLen; i++) {
int intTmp = arrB[i];
// 把負數轉換爲正數
while (intTmp < 0) {
intTmp = intTmp + 256;
}
// 小於0F的數需要在前面補0
if (intTmp < 16) {
sb.append("0");
}
sb.append(Integer.toString(intTmp, 16));
}
return sb.toString();
}
/**
* 將表示16進制值的字符串轉換爲byte數組, 和public static String byteArr2HexStr(byte[] arrB)
* 互爲可逆的轉換過程
*
* @param strIn
* 需要轉換的字符串
* @return 轉換後的byte數組
* @throws Exception
* 本方法不處理任何異常,所有異常全部拋出
* @author <a href="mailto:[email protected]">LiGuoQing</a>
*/
public static byte[] hexStr2ByteArr(String strIn) throws Exception {
byte[] arrB = strIn.getBytes();
int iLen = arrB.length;
// 兩個字符表示一個字節,所以字節數組長度是字符串長度除以2
byte[] arrOut = new byte[iLen / 2];
for (int i = 0; i < iLen; i = i + 2) {
String strTmp = new String(arrB, i, 2);
arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
}
return arrOut;
}