java库实现sm4加解密
时间: 2024-04-27 16:17:25 浏览: 16
Java库中可以使用Bouncy Castle库来实现SM4加解密算法。Bouncy Castle是一个流行的Java密码学库,提供了各种加密算法的实现。
要使用Bouncy Castle库实现SM4加解密,首先需要在项目中引入Bouncy Castle库的依赖。可以通过Maven或Gradle等构建工具添加以下依赖:
Maven:
```xml
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.68</version>
</dependency>
```
Gradle:
```groovy
implementation 'org.bouncycastle:bcprov-jdk15on:1.68'
```
接下来,可以使用以下代码示例来进行SM4加解密:
```java
import org.bouncycastle.crypto.engines.SM4Engine;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.util.encoders.Hex;
import java.nio.charset.StandardCharsets;
public class SM4EncryptionExample {
public static void main(String[] args) throws Exception {
// 密钥(16字节)
byte[] key = Hex.decode("0123456789abcdeffedcba9876543210");
// 初始化向量(16字节)
byte[] iv = Hex.decode("0123456789abcdef");
// 明文
String plaintext = "Hello, SM4!";
byte[] plaintextBytes = plaintext.getBytes(StandardCharsets.UTF_8);
// 加密
PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new SM4Engine()));
cipher.init(true, new ParametersWithIV(new KeyParameter(key), iv));
byte[] ciphertextBytes = new byte[cipher.getOutputSize(plaintextBytes.length)];
int len = cipher.processBytes(plaintextBytes, 0, plaintextBytes.length, ciphertextBytes, 0);
cipher.doFinal(ciphertextBytes, len);
// 输出密文
String ciphertext = Hex.toHexString(ciphertextBytes);
System.out.println("Ciphertext: " + ciphertext);
// 解密
cipher.init(false, new ParametersWithIV(new KeyParameter(key), iv));
byte[] decryptedBytes = new byte[cipher.getOutputSize(ciphertextBytes.length)];
len = cipher.processBytes(ciphertextBytes, 0, ciphertextBytes.length, decryptedBytes, 0);
cipher.doFinal(decryptedBytes, len);
// 输出解密后的明文
String decryptedText = new String(decryptedBytes, StandardCharsets.UTF_8);
System.out.println("Decrypted Text: " + decryptedText);
}
}
```
以上代码示例演示了如何使用Bouncy Castle库实现SM4加解密。首先定义了密钥和初始化向量,然后使用PaddedBufferedBlockCipher类进行加解密操作。加密时使用`cipher.init(true, ...)`,解密时使用`cipher.init(false, ...)`。最后输出了加密后的密文和解密后的明文。