将tweetnacl.js与Twe​​etNaclFastjava混合以进行非对称加密

问题描述

我们的项目正在使用带有nacl.box和临时密钥的非对称加密：

    encrypt(pubKey,msg) {
        if (typeof msg !== 'string') {
            msg = JSON.stringify(msg)
        }
        let ephemKeys = nacl.box.keyPair()
        let msgArr = nacl.util.decodeUTF8(msg)
        let nonce = nacl.randomBytes(nacl.box.nonceLength)
        p(`naclRsa.pubKey=${this.pubKey}`)
        let encrypted = nacl.box(
            msgArr,nonce,nacl.util.decodeBase64(pubKey),ephemKeys.secretKey
        )
        let nonce64 = nacl.util.encodeBase64(nonce)
        let pubKey64 = nacl.util.encodeBase64(ephemKeys.publicKey)
        let encrypted64 = nacl.util.encodeBase64(encrypted)
        return {nonce: nonce64,ephemPubKey: pubKey64,encrypted: encrypted64}
    }

我们目前有node.js个应用程序，可以对这些消息进行解密。我们希望为某些功能使用jvm语言。 tweet-nacl上似乎没有jvm的老牌玩家，但似乎

• tweetnacl-java https://github.com/InstantWebP2P/tweetnacl-java

及其推荐的实现方式

°tweetnacl-fast https://github.com/InstantWebP2P/tweetnacl-java/blob/master/src/main/java/com/iwebpp/crypto/TweetNaclFast.java

是受欢迎的。

目前尚不清楚该库中使用临时密钥进行asymmetric加密的类似方式。支持吗？请注意，如果java不支持kotlin或tweetnacl-java，我将开放。

解决方法

tweetnacl-java是tweetnacl-js的端口。因此，期望两者都提供相同的功能。至少对于发布的方法是这种情况，可以在Java端使用 TweetNaclFast 如下实现：

import java.nio.charset.StandardCharsets;
import java.util.Base64;

import com.iwebpp.crypto.TweetNaclFast;
import com.iwebpp.crypto.TweetNaclFast.Box;
import com.iwebpp.crypto.TweetNaclFast.Box.KeyPair;

...

private static EncryptedData encrypt(byte[] pubKey,String msg) {
    KeyPair ephemKeys = Box.keyPair();
    byte[] msgArr = msg.getBytes(StandardCharsets.UTF_8);
    byte[] nonce = TweetNaclFast.randombytes(Box.nonceLength);
    
    Box box = new Box(pubKey,ephemKeys.getSecretKey());
    byte[] encrypted = box.box(msgArr,nonce);
    
    String nonce64 = Base64.getEncoder().encodeToString(nonce);
    String ephemPubKey64 = Base64.getEncoder().encodeToString(ephemKeys.getPublicKey());
    String encrypted64 = Base64.getEncoder().encodeToString(encrypted);
    return new EncryptedData(nonce64,ephemPubKey64,encrypted64);
}

...

class EncryptedData {
    public EncryptedData(String nonce,String ephemPubKey,String encrypted) {
        this.nonce = nonce;
        this.ephemPubKey = ephemPubKey;
        this.encrypted = encrypted;
    }
    public String nonce;
    public String ephemPubKey;
    public String encrypted;
}

---

为了证明双方都兼容，下面将在Java方面对纯文本进行加密，然后在JavaScript方面对纯文本进行解密：

• 首先，在JavaScript端需要一个密钥对，其公钥（publicKeyJS）被传递到Java端。 JavaScript端的密钥对可以如下生成：

  let keysJS = nacl.box.keyPair();
  let secretKeyJS = keysJS.secretKey;
  let publicKeyJS = keysJS.publicKey;
  console.log("Secret key: " + nacl.util.encodeBase64(secretKeyJS));
  console.log("Public key: " + nacl.util.encodeBase64(publicKeyJS));
  

  具有以下示例输出：

  Secret key: YTxAFmYGm4yV2OP94E4pcD6LSsN4gcSBBAlU105l7hw= 
  Public key: BDXNKDHeq0vILm8oawAGAQtdIsgwethzBTBqmsWI+R8=
  

• 然后使用上面发布的encrypt方法（和publicKeyJS）在Java端进行加密：

  byte[] publicKeyJS = Base64.getDecoder().decode("BDXNKDHeq0vILm8oawAGAQtdIsgwethzBTBqmsWI+R8=");
  EncryptedData encryptedFromJava = encrypt(publicKeyJS,"I've got a feeling we're not in Kansas anymore...");
  System.out.println("Nonce: " + encryptedFromJava.nonce);
  System.out.println("Ephemeral public key: " + encryptedFromJava.ephemPubKey);
  System.out.println("Ciphertext: " + encryptedFromJava.encrypted);
  

  具有以下示例输出：

  Nonce: FcdzXfYwSbI0nq2WXsLe9aAh94vXSoWd
  Ephemeral public key: Mde+9metwF1jIEij5rlZDHjAStR/pd4BN9p5JbZleSg=
  Ciphertext: hHo7caCxTU+hghcFZFv+djAkSlWKnC12xj82V2R/Iz9GdOMoTzjoCDcz9m/KbRN6i5dkYi3+Gf0YTtKlZQWFooo=
  

• JS端的解密给出原始明文（使用secretKeyJS）：

  let nonce = "FcdzXfYwSbI0nq2WXsLe9aAh94vXSoWd";
  let ephemPubKey = "Mde+9metwF1jIEij5rlZDHjAStR/pd4BN9p5JbZleSg=";
  let encrypted = "hHo7caCxTU+hghcFZFv+djAkSlWKnC12xj82V2R/Iz9GdOMoTzjoCDcz9m/KbRN6i5dkYi3+Gf0YTtKlZQWFooo=";
  let secretKeyJS = nacl.util.decodeBase64("YTxAFmYGm4yV2OP94E4pcD6LSsN4gcSBBAlU105l7hw=");
  let decryptedFromJS = decrypt(secretKeyJS,{nonce: nonce,ephemPubKey: ephemPubKey,encrypted: encrypted});
  console.log(nacl.util.encodeUTF8(decryptedFromJS)); // I've got a feeling we're not in Kansas anymore...
    
  function decrypt(secretKey,ciphertext){
      let decrypted = nacl.box.open(
          nacl.util.decodeBase64(ciphertext.encrypted),nacl.util.decodeBase64(ciphertext.nonce),nacl.util.decodeBase64(ciphertext.ephemPubKey),secretKey
      );
      return decrypted;
  }

  <script src="https://cdn.jsdelivr.net/npm/tweetnacl-util@0.15.1/nacl-util.min.js"></script>
  <script src="https://cdn.jsdelivr.net/npm/tweetnacl@1.0.3/nacl.min.js"></script>