在 dotnet core 中进行 AES 解密时获取空字符串

Question

我正在我的 Angular 项目上实现 AES 加密，并在我的 dotnet 代码中对其进行解密。 使用 PBKDF2 显式地实现这一点，而不是依赖隐式推导（CryptoJS.AES.encrypt(text, password)）。我不明白这究竟是哪里失败了。

在 Angular 端使用 crypto-js 进行加密：

import { Injectable } from '@angular/core';
import * as CryptoJS from 'crypto-js';

@Injectable({
    providedIn: 'root',
})
export class CryptoService {
private secretkey = "MyOwnKey";

encrypt(text: string): string {
    // random salt for derivation
    let keySize = 256;
    let salt = CryptoJS.lib.WordArray.random(16);
    // well known algorithm to generate key
    let key = CryptoJS.PBKDF2(this.secretkey, salt, {
        keySize: keySize/32,
        iterations: 100
        });
    // random IV
    let iv = CryptoJS.lib.WordArray.random(16);      
    // specify everything explicitly
    let encrypted = CryptoJS.AES.encrypt(text, key, { 
        iv: iv, 
        padding: CryptoJS.pad.Pkcs7,
        mode: CryptoJS.mode.CBC        
    });
    // combine everything together in base64 string
    let result = CryptoJS.enc.Base64.stringify(salt.concat(iv).concat(encrypted.ciphertext));
    return result;
}
}

Dotnet端解密：

public string decrypt(string cipherText)
    {
        if (string.IsNullOrEmpty(cipherText))
            return string.Empty;
        
        try
        {
            byte[] cipherBytes = Convert.FromBase64String(cipherText);

            using (Aes encryptor = Aes.Create())
            {
                // extract salt (first 16 bytes)
                byte[] salt = new byte[16];
                Array.Copy(cipherBytes, 0, salt, 0, 16);
                _logger.LogInformation("salt: {salt}", salt);

                // extract iv (next 16 bytes)
                byte[] iv = new byte[16];
                Array.Copy(cipherBytes, 16, iv, 0, 16);
                _logger.LogInformation("iv: {iv}", iv);

                // the rest is encrypted data
                byte[] encrypted = new byte[cipherBytes.Length - 32];
                Array.Copy(cipherBytes, 32, encrypted, 0, cipherBytes.Length - 32);
                _logger.LogInformation("encrypted: {encrypted}", encrypted);

                Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes("MyOwnKey", salt, 100);
                encryptor.Key = pdb.GetBytes(32);
                encryptor.Padding = PaddingMode.PKCS7;
                encryptor.Mode = CipherMode.CBC;
                encryptor.IV = iv;

                string plaintext;
                using (MemoryStream ms = new MemoryStream(encrypted))
                {
                    using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Read))
                    {
                        using (var reader = new StreamReader(cs, Encoding.UTF8))
                        {
                            plaintext = reader.ReadToEnd();
                            reader?.Dispose();
                        }
                        cs?.Dispose();
                    }
                }
                var cbLength = plaintext.Length;
                _logger.LogInformation("plaintext Lenght: {cbLength}", cbLength);
                return plaintext;
            }
        }
        catch (Exception ex)
        {
            return "Decryption error: " + ex.Message;
        }
    }

当我调用此解密方法时，我得到一个空字符串。为什么会这样？

Answer 1

改变：

Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes("MyOwnKey", salt, 100);

到

Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes("MyOwnKey", salt, 100,  HashAlgorithmName.SHA256);