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com.siashan.toolkit.crypt.asymmetric.RSAUtils Maven / Gradle / Ivy
package com.siashan.toolkit.crypt.asymmetric;
import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
public class RSAUtils {
public static final String KEY_ALGORITHM = "RSA";
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
private static final String PUBLIC_KEY = "RSAPublicKey";
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;
public static String getPublicKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
// byte[] publicKey = key.getEncoded();
return Base64.getEncoder().encodeToString(key.getEncoded());
}
public static String getPrivateKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
// byte[] privateKey = key.getEncoded();
return Base64.getEncoder().encodeToString(key.getEncoded());
}
public static byte[] decryptBASE64(String key) throws Exception {
// return (new BASE64Decoder()).decodeBuffer(key);
return Base64.getDecoder().decode(key);
}
public static String encryptBASE64(byte[] key) throws Exception {
// return (new BASE64Encoder()).encodeBuffer(key);
return Base64.getEncoder().encodeToString(key);
}
public static Map initKey() 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 keyMap = new HashMap(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
public static Map initKey(String seed) throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
SecureRandom secureRandom = new SecureRandom();
secureRandom.setSeed(seed.getBytes());
//keyPairGen.initialize(KEY_SIZE, secureRandom);
keyPairGen.initialize(1024, secureRandom);
KeyPair keyPair = keyPairGen.generateKeyPair();
DSAPublicKey publicKey = (DSAPublicKey) keyPair.getPublic();
DSAPrivateKey privateKey = (DSAPrivateKey) keyPair.getPrivate();
Map keyMap = new HashMap(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
* 用私钥对信息生成数字签名
*
* @param data 已加密数据
* @param privateKey 私钥(BASE64编码)
* @return 返回签名字后Base64后的签名字符串
* @throws Exception
*/
public static String sign(byte[] data, String privateKey) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(privateKey);
byte[] keyBytes = Base64.getDecoder().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 (new BASE64Encoder()).encode(signature.sign());
return Base64.getEncoder().encodeToString(signature.sign());
}
/**
* 校验数字签名
*
* @param data 已加密数据
* @param publicKey 公钥(BASE64编码)
* @param sign 数字签名
* @return 校验签名
* @throws Exception
*/
public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(publicKey);
byte[] keyBytes = Base64.getDecoder().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((new BASE64Decoder()).decodeBuffer(sign));
return signature.verify(Base64.getDecoder().decode(sign));
}
/**
* 私钥解密
*
* @param encryptedData 已加密数据
* @param privateKey 私钥(BASE64编码)
* @return 返回解密后的字节
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(privateKey);
byte[] keyBytes = Base64.getDecoder().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;
// 对数据分段解密
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;
}
/**
* 公钥解密
*
* @param encryptedData 已加密数据
* @param publicKey 公钥(BASE64编码)
* @return 返回解密后的字节
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(publicKey);
byte[] keyBytes = Base64.getDecoder().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;
// 对数据分段解密
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;
}
/**
* 公钥加密
*
* @param data 源数据
* @param publicKey 公钥(BASE64编码)
* @return 返回加密后的字节
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(publicKey);
byte[] keyBytes = Base64.getDecoder().decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
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;
// 对数据分段加密
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;
}
/**
* 私钥加密
*
* @param data 源数据
* @param privateKey 私钥(BASE64编码)
* @return 返回加密后的字节
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {
// byte[] keyBytes = (new BASE64Decoder()).decodeBuffer(privateKey);
byte[] keyBytes = Base64.getDecoder().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;
// 对数据分段加密
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;
}
public static void main(String[] args) {
Map keyMap;
try {
keyMap = initKey();
String publicKey = getPublicKey(keyMap);
System.out.println("publicKey: ");
System.out.println(publicKey);
String privateKey = getPrivateKey(keyMap);
System.out.println("privateKey: ");
System.out.println(privateKey);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("-----------------------------------------");
Map keyMapA;
Map keyMapB;
try {
keyMapA = initKey();
keyMapB = initKey();
System.out.println(keyMapA.equals(keyMapB));
String ApublicKey = getPublicKey(keyMapA);
String BpublicKey = getPublicKey(keyMapB);
String AprivateKey = getPrivateKey(keyMapA);
String BprivateKey = getPrivateKey(keyMapB);
System.out.println("-------------");
System.out.println("ApublicKey:" + ApublicKey);
System.out.println("AprivateKey:" + AprivateKey);
System.out.println("-------------");
System.out.println("BpublicKey:" + BpublicKey);
System.out.println("BprivateKey:" + BprivateKey);
System.out.println("----------------------------------------");
String source1 = "这个表要要加密的内容，我们现在开始处理。";
System.out.println("加密前文字：\n" + source1);
byte[] data1 = source1.getBytes();
byte[] encodedData1 = encryptByPublicKey(data1, ApublicKey);
System.out.println("加密后文字：\n" + new String(encodedData1));
byte[] decodedData1 = decryptByPrivateKey(encodedData1, AprivateKey);
String target1 = new String(decodedData1);
System.out.println("解密后文字: \n" + target1);
String source2 = "这个表要要加密的内容，我们现在开始处理，用B的私钥进行加密，然后得取字符串，发给A，A收到加密字符串后，利用B的公钥进行解密。";
System.out.println("原文字：\n" + source2);
byte[] data2 = source2.getBytes();
byte[] encodedData2 = encryptByPrivateKey(data2, BprivateKey);
System.out.println("加密后：\n" + new String(encodedData2));
byte[] decodedData2 = decryptByPublicKey(encodedData2, BpublicKey);
String target2 = new String(decodedData2);
System.out.println("解密后: \n" + target2);
System.out.println("私钥签名——公钥验证签名");
String sign2 = sign(encodedData2, BprivateKey);
System.out.println("签名: \n" + sign2);
boolean status2 = verify(encodedData2, BpublicKey, sign2);
System.out.println("验证结果: \n" + status2);
} catch (Exception e) {
e.printStackTrace();
}
}
}
