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easyopen mini版，保留基本签名校验，文档功能。https://gitee.com/durcframework/easyopen
package com.gitee.easyopen.util;
import org.apache.commons.codec.binary.Base64;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
/**
* RSA加解密工具
* @author tanghc
*/
public class RSAUtil {
public static String RSA_ALGORITHM = "RSA";
/**
* 创建公钥私钥
*
* @return 返回公私钥对
* @throws Exception
*/
public static KeyStore createKeys() throws Exception {
KeyPairGenerator keyPairGeno = KeyPairGenerator.getInstance(RSA_ALGORITHM);
keyPairGeno.initialize(1024);
KeyPair keyPair = keyPairGeno.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
KeyStore keyStore = new KeyStore();
keyStore.setPublicKey(Base64.encodeBase64String(publicKey.getEncoded()));
keyStore.setPrivateKey(Base64.encodeBase64String(privateKey.getEncoded()));
return keyStore;
}
/**
* 获取公钥对象
*
* @param pubKeyData 公钥
* @return 返回公钥对象
* @throws Exception
*/
public static RSAPublicKey getPublicKey(byte[] pubKeyData) throws Exception {
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(pubKeyData);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_ALGORITHM);
return (RSAPublicKey) keyFactory.generatePublic(keySpec);
}
/**
* 获取公钥对象
*
* @param pubKey
* 公钥
* @return 返回私钥对象
* @throws Exception
*/
public static RSAPublicKey getPublicKey(String pubKey) throws Exception {
return getPublicKey(Base64.decodeBase64(pubKey));
}
/**
* 获取私钥对象
*
* @param priKey
* 私钥
* @return 私钥对象
* @throws Exception
*/
public static RSAPrivateKey getPrivateKey(String priKey) throws Exception {
return getPrivateKey(Base64.decodeBase64(priKey));
}
/**
* 通过私钥byte[]将公钥还原，适用于RSA算法
*
* @param keyBytes
* @return 返回私钥
* @throws Exception
*/
public static RSAPrivateKey getPrivateKey(byte[] keyBytes) throws Exception {
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_ALGORITHM);
return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
}
/**
* 公钥加密
*
* @param data 待加密内容
* @param publicKey 公钥
* @return 返回密文
* @throws Exception
*/
public static String encryptByPublicKey(String data, RSAPublicKey publicKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
// 模长
int key_len = publicKey.getModulus().bitLength() / 8;
// 加密数据长度 <= 模长-11
String[] datas = splitString(data, key_len - 11);
String mi = "";
// 如果明文长度大于模长-11则要分组加密
for (String s : datas) {
mi += bcd2Str(cipher.doFinal(s.getBytes()));
}
return mi;
}
public static String encryptByPrivateKey(String data, String privateKey) throws Exception {
return encryptByPrivateKey(data, getPrivateKey(privateKey));
}
/**
* 私钥加密
*
* @param data 待加密数据
* @param privateKey 私钥
* @return 返回密文
* @throws Exception
*/
public static String encryptByPrivateKey(String data, RSAPrivateKey privateKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
// 模长
int key_len = privateKey.getModulus().bitLength() / 8;
// 加密数据长度 <= 模长-11
String[] datas = splitString(data, key_len - 11);
String mi = "";
// 如果明文长度大于模长-11则要分组加密
for (String s : datas) {
mi += bcd2Str(cipher.doFinal(s.getBytes()));
}
return mi;
}
public static String decryptByPrivateKey(String data, String privateKey) throws Exception {
return decryptByPrivateKey(data, getPrivateKey(privateKey));
}
/**
* 私钥解密
*
* @param data 待解密内容
* @param privateKey 私钥
* @return 返回明文
* @throws Exception
*/
public static String decryptByPrivateKey(String data, RSAPrivateKey privateKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
// 模长
int key_len = privateKey.getModulus().bitLength() / 8;
byte[] bytes = data.getBytes();
byte[] bcd = ASCII_To_BCD(bytes, bytes.length);
// 如果密文长度大于模长则要分组解密
String ming = "";
byte[][] arrays = splitArray(bcd, key_len);
for (byte[] arr : arrays) {
ming += new String(cipher.doFinal(arr));
}
return ming;
}
/**
* 公钥解密
*
* @param data 待解密内容
* @param rsaPublicKey 公钥
* @return 返回明文
* @throws Exception
*/
public static String decryptByPublicKey(String data, RSAPublicKey rsaPublicKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, rsaPublicKey);
// 模长
int key_len = rsaPublicKey.getModulus().bitLength() / 8;
byte[] bytes = data.getBytes();
byte[] bcd = ASCII_To_BCD(bytes, bytes.length);
// 如果密文长度大于模长则要分组解密
String ming = "";
byte[][] arrays = splitArray(bcd, key_len);
for (byte[] arr : arrays) {
ming += new String(cipher.doFinal(arr));
}
return ming;
}
/**
* ASCII码转BCD码
*
*/
public static byte[] ASCII_To_BCD(byte[] ascii, int asc_len) {
byte[] bcd = new byte[asc_len / 2];
int j = 0;
for (int i = 0; i < (asc_len + 1) / 2; i++) {
bcd[i] = asc_to_bcd(ascii[j++]);
bcd[i] = (byte) (((j >= asc_len) ? 0x00 : asc_to_bcd(ascii[j++]) & 0xff) + (bcd[i] << 4));
}
return bcd;
}
public static byte asc_to_bcd(byte asc) {
byte bcd;
if ((asc >= '0') && (asc <= '9')) {
bcd = (byte) (asc - '0');
} else if ((asc >= 'A') && (asc <= 'F')) {
bcd = (byte) (asc - 'A' + 10);
} else if ((asc >= 'a') && (asc <= 'f')) {
bcd = (byte) (asc - 'a' + 10);
} else {
bcd = (byte) (asc - 48);
}
return bcd;
}
/**
* BCD转字符串
*/
public static String bcd2Str(byte[] bytes) {
char[] temp = new char[bytes.length * 2];
char val;
for (int i = 0; i < bytes.length; i++) {
val = (char) (((bytes[i] & 0xf0) >> 4) & 0x0f);
temp[i * 2] = (char) (val > 9 ? val + 'A' - 10 : val + '0');
val = (char) (bytes[i] & 0x0f);
temp[i * 2 + 1] = (char) (val > 9 ? val + 'A' - 10 : val + '0');
}
return new String(temp);
}
/**
* 拆分字符串
*/
public static String[] splitString(String string, int len) {
int x = string.length() / len;
int y = string.length() % len;
int z = 0;
if (y != 0) {
z = 1;
}
String[] strings = new String[x + z];
String str = "";
for (int i = 0; i < x + z; i++) {
if (i == x + z - 1 && y != 0) {
str = string.substring(i * len, i * len + y);
} else {
str = string.substring(i * len, i * len + len);
}
strings[i] = str;
}
return strings;
}
/**
* 拆分数组
*/
public static byte[][] splitArray(byte[] data, int len) {
int x = data.length / len;
int y = data.length % len;
int z = 0;
if (y != 0) {
z = 1;
}
byte[][] arrays = new byte[x + z][];
byte[] arr;
for (int i = 0; i < x + z; i++) {
arr = new byte[len];
if (i == x + z - 1 && y != 0) {
System.arraycopy(data, i * len, arr, 0, y);
} else {
System.arraycopy(data, i * len, arr, 0, len);
}
arrays[i] = arr;
}
return arrays;
}
/*public static void main(String[] args) throws Exception {
KeyStore keys = createKeys();
String pubKey = keys.getPublicKey();
System.out.println("pubKey:");
System.out.println(pubKey);
String priKey = keys.getPrivateKey();
System.out.println("priKey:");
System.out.println(priKey);
String ming = "6460201d23954f8e90cf79b818844ca0";
// 用公钥加密
String mi = encryptByPublicKey(ming, getPublicKey(pubKey));
System.out.println("mi : " + mi);
// 用私钥解密
System.out.println("ming : " + decryptByPrivateKey(mi, getPrivateKey(priKey)));
// 用私钥加密
String mi2 = encryptByPrivateKey(ming, getPrivateKey(priKey));
System.out.println("mi2 : " + mi2);
// 用公钥解密
System.out.println("ming2 : " + decryptByPublicKey(mi2, getPublicKey(pubKey)));
}*/
}