JAVA 语言AES CBC模式加解密数据实现
在多可文档系统中文件接口需要和其他系统实现用户统一登录，其他数据加密传输，要保障算法和数据的一致性对系统接口使用有很大帮助。系统选择使用 AES加密算法 的CBC模式（128位密钥），实现各系统间加密数据的传输。多可提供各种语言的算法实现，以下是 JAVA 语言的具体算法实现（其他语言参考博主相关文章）：
加解密文本用16进制字符串表示，如果您需要base64编码请修改编码和解密部分即可。
package aes;
import java.io.BufferedReader;
import java.io. File Reader;
import java.io.IO Exception ;
import java.net.URLEncoder;
import javax .crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class hello {
public static final String Iv = “1234567890ABCDEF”;
public static final String KEY_ALGORITHM = “AES”;
public static final String CIPHER_ALGORITHM_CBC = “AES/CBC/NoPadding”;
public static String byte s2HexString(byte[] b) {
StringBuffer result = new StringBuffer();
for (int i = 0; i < b.length; i++) {
result.append(String.format(“%02X”,b[i]));
}
return result.toString();
}
public static byte[] aesCBCEncrypt(byte[] data, byte[] key) throws Exception {
if(key.length != 16) {
throw new RuntimeException(“Invalid AES key length (must be 16 bytes)”);
} else {
Cipher cipher = Cipher. getInstance (CIPHER_ALGORITHM_CBC);
int blockSize = cipher.getBlockSize();
int length = data.length;
// 计算需填充长度
if (length % blockSize != 0) {
length = length + (blockSize – (length % blockSize));
}
byte[] plaintext = new byte[length];
// 拷贝数据
System.array copy (data, 0, plaintext, 0, data.length);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, KEY_ALGORITHM), new IvParameterSpec(IV.getBytes()));
return cipher.doFinal(plaintext);
}
}
private static byte charToByte(char c) {
return (byte) “0123456789ABCDEF”.indexOf(c);
}
public static byte[] hex2Bytes(String s) throws Exception{
int len = s.length();
if (len % 2 == 1){
throw new RuntimeException(“Invalid data”);
}
char[] hexChars = s.toCharArray();
byte[] r = new byte[len / 2];
for (int i = 0; i < len / 2; i++) {
int pos = i * 2;
r[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return r;
}
public static String aesCBCDecrypt(byte[] data, byte[] key) throws Exception {
if(key.length != 16) {
throw new RuntimeException(“Invalid AES key length (must be 16 bytes)”);
} else {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM_CBC);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, KEY_ALGORITHM), new IvParameterSpec(IV.getBytes()));
//
byte[] plaintext = cipher.doFinal(data);
return new String(plaintext, “utf-8”).trim();
}
}
public static void main(String[] args) {
String key = “2018201820182018”;
String inStr = “多可文档管理系统”;
try
{
//加密
byte[] outBytes = aesCBCEncrypt(inStr.getBytes(“utf-8”), key.getBytes(“utf-8”));
String s = bytes2HexString(outBytes);
System.out.println(s);
//解密
String s2 = aesCBCDecrypt(hex2Bytes(s), key.getBytes(“utf-8”));
System.out.println(s2);
} catch (Exception e) {
e.printStackTrace();
}
}
}
