JWT公私鑰解析

一 生成公私鑰

 

  public static void main(String[] args) throws NoSuchAlgorithmException {

        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");

        KeyPair keyPair = keyPairGenerator.generateKeyPair();

        Key publicKey = keyPair.getPublic();

        Key privateKey = keyPair.getPrivate();

        System.out.println( (new BASE64Encoder()).encodeBuffer(privateKey.getEncoded()));

        System.out.println(  (new BASE64Encoder()).encodeBuffer(publicKey.getEncoded()));

        

    }

 

生成公私鑰備用

二 頒發token項目使用私鑰生成

  通過BASE64編碼轉換為私鑰

 

 

byte[] keyBytes;

keyBytes = Base64.getDecoder().decode(privateKey.getBytes());

PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

return keyFactory.generatePrivate(keySpec);

　　

 

通過私鑰生成數據 claim 為自定義數據

  public static String ecode(String account, String subject, long expired, Map<String, Object> data, Key privateKey)

{





    try

    {

        JSONObject HEADER =     JSONObject.parseObject("{'type':'JWT','sign':'RS256'}");

        Long nowMillis = System.currentTimeMillis();

        Date createTime = new Date(nowMillis);

        Date expiredTime = new Date(nowMillis + expired);

        JwtBuilder builder = Jwts.builder();

        builder.setHeader(HEADER).setId(UUID.randomUUID().toString()).setIssuer("頒發者").setAudience(account).setSubject(subject).setIssuedAt(createTime).setNotBefore(createTime).setExpiration(expiredTime).signWith(SIGNATURE_TYPE, privateKey);

        builder.claim("data", data);

        return builder.compact();

    }

    catch (Exception e)

    {

        e.printStackTrace();

    }

    return "";

}

　　

 

三 通過公鑰獲取數據

  通過BASE64編碼轉換為公鑰

byte[] keyBytes = Base64.getDecoder().decode("publicKeyString");

X509EncodedKeySpec keySpec=new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory= KeyFactory.getInstance("RSA");

keyFactory.generatePublic(keySpec);

　　

通過公鑰解析數據

String jwtString = "";

// 使用公鑰解析JWT內容

Claims claims = dcode(jwtString,  keyFactory.generatePublic(keySpec));

System.out.println(claims.getExpiration());

System.out.println(new Date());

System.out.println(claims.getExpiration());

System.out.println(claims.get("data"));

System.out.println();