用Java中的密钥计算HMAC-SHA512

Question

我想专门构建一个函数，该函数生成带有此站点提供的密钥的HMAC：

http://www.freeformatter.com/hmac-
generator.html

Java 8库仅提供MessageDigest和KeyGenerator，它们均仅最多支持SH256。

谷歌也没有给我任何实现生成HMAC的结果。

有人知道实现吗？

我有这段代码来生成普通的SH256，但是我想这对我没有太大帮助：

   public static String get_SHA_512_SecurePassword(String passwordToHash) throws Exception {
    String generatedPassword = null;

    MessageDigest md = MessageDigest.getInstance("SHA-512");
    byte[] bytes = md.digest(passwordToHash.getBytes("UTF-8"));
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < bytes.length; i++) {
        sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
    }
    generatedPassword = sb.toString();
    System.out.println(generatedPassword);
    return generatedPassword;
}

Answer 1

希望这可以帮助：

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class Test1 {

    private static final String HMAC_SHA512 = "HmacSHA512";

    public static void main(String[] args) {
        Mac sha512Hmac;
        String result;
        final String key = "Welcome1";

        try {
            final byte[] byteKey = key.getBytes(StandardCharsets.UTF_8);
            sha512Hmac = Mac.getInstance(HMAC_SHA512);
            SecretKeySpec keySpec = new SecretKeySpec(byteKey, HMAC_SHA512);
            sha512Hmac.init(keySpec);
            byte[] macData = sha512Hmac.doFinal("My message".getBytes(StandardCharsets.UTF_8));

            // Can either base64 encode or put it right into hex
            result = Base64.getEncoder().encodeToString(macData);
            //result = bytesToHex(macData);
        } catch (UnsupportedEncodingException | InvalidKeyException | NoSuchAlgorithmException e) {
            e.printStackTrace();
        } finally {
            // Put any cleanup here
            System.out.println("Done");
        }
    }
}

从字节数组转换为十六进制请参阅本计算器答案：这里