seers
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Java 小白提问,这段代码是标准 RSA 加密吗

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  •   seers · Oct 4, 2022 · 3568 views
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    This topic created in 1470 days ago, the information mentioned may be changed or developed.

    对加密方面不太熟,请大佬帮忙看看

    public static String encryptByPublicKey(String source, byte[] key) throws Exception {
        byte[] data = source.getBytes("utf-8");
        byte[] keyBytes = key;
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        Key publicKey = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(1, publicKey);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        int i = 0;
        while (inputLen - offSet > 0) {
          byte[] cache;
          if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
            cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
          } else {
            cache = cipher.doFinal(data, offSet, inputLen - offSet);
          } 
          out.write(cache, 0, cache.length);
          i++;
          offSet = i * MAX_ENCRYPT_BLOCK;
        } 
        byte[] encryptedData = out.toByteArray();
        out.close();
        return (new String(Base64.encodeBase64(encryptedData), "UTF8")).replaceAll("\r\n", "");
      }
    
    9 replies  •  2022-10-04 11:24:11 +08:00
    F281M6Dh8DXpD1g2
        1
    F281M6Dh8DXpD1g2  
       Oct 4, 2022 via iPhone
    RSA/ECB/PKCS1Padding
    这不都写了
    seers
        2
    seers  
    OP
       Oct 4, 2022
    @liprais 我在用 go 重写某个接口,其中会用到这个校验,但是我调用 go 的标准 rsa 实现访问接口一直报错
    F281M6Dh8DXpD1g2
        3
    F281M6Dh8DXpD1g2  
       Oct 4, 2022 via iPhone
    @seers 很显然你写的跟 java 的实现不一样,我猜问题出在 padding 上
    wa8n
        4
    wa8n  
       Oct 4, 2022
    贴出 go 代码和对应的 Java 明文、key 、密文更好解决
    eason1874
        5
    eason1874  
       Oct 4, 2022
    很明显是内置标准 RSA 库,但他是分块加密,然后再把结果拼接起来,所以你解密的时候也要分块

    MAX_ENCRYPT_BLOCK 是它明文块长度,根据它可以算出密文块有多长,不过代码里应该还有对应的 MAX_DECRYPT_BLOCK 表示密文块有多长,直接看那个就行
    seers
        6
    seers  
    OP
       Oct 4, 2022
    lysS
        7
    lysS  
       Oct 4, 2022
    最后对密文算了 base64 的,要用 DecryptPKCS1v15 进行解密
    seers
        8
    seers  
    OP
       Oct 4, 2022
    @eason1874 原来如此,我还以为 while 循环是标准的一部分,看来还是稍微魔改了一下
    Bingchunmoli
        9
    Bingchunmoli  
       Oct 4, 2022 via Android
    @seers 因为不改的话,加密长度问题可能抛异常
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