如何从数据库中读取加密值并将其与 ASP.NET Core 中的另一个值进行比较？

Posted 2023-03-28

【中文标题】如何从数据库中读取加密值并将其与 ASP.NET Core 中的另一个值进行比较？

【英文标题】：How to read an encrypted value from database and compare it with another value in ASP.NET Core?

【发布时间】：2021-10-22 20:32:57

【问题描述】：

使用的工具：Visual Studio 2019、ASP.NET Core 5.0、SQL Server 2014

我加密了一个日期(Datetime.Today.AddDays(8))，并成功将其保存到数据库中。

我尝试使用@Model.Decrypt(Model.Date.DateEnc) 解密该值，但它不起作用。

如何从数据库中检索加密值、解密并将解密后的值与今天的日期进行比较？

我的 Decrypt.cshtml 页面是：

@if(Model.Decrypt(encryptedValue).toString() == Datetime.Today.toString())
<p>Correct</p>
else
<p>Wrong</p>

我的 Decrypt.cshtml.cs 页面是：

    public string Decrypt(string cipherText)
    
        string EncryptionKey = " Bt2a";
        cipherText = cipherText.Replace(" ", "+");
        byte[] cipherBytes = Convert.FromBase64String(cipherText);
        using (Aes encryptor = Aes.Create())
        
            Rfc2898DeriveBytes pdb = new(EncryptionKey, new byte[]  0x01, 0x22, 0xcc, 0x0e, 0x50, 0x4d, 0x05, 0xa4, 0x4f, 0xff, 0xe3, 0x69, 0x7a );
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using MemoryStream ms = new();
            using (CryptoStream cs = new(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
            
                cs.Write(cipherBytes, 0, cipherBytes.Length);
                cs.Close();
            
            cipherText = Encoding.Unicode.GetString(ms.ToArray());
        
        return cipherText;
    

加密方法：

public string Encrypt(string icu)
        
            string EncryptionKey = "Bt2a";
            byte[] clearBytes = Encoding.Unicode.GetBytes(icu);
            using (Aes encryptor = Aes.Create())
            
                Rfc2898DeriveBytes pdb = new(EncryptionKey, new byte[]  0x01, 0x22, 0xcc, 0x0e, 0x50, 0x4d, 0x05, 0xa4, 0x4f, 0xff, 0xe3, 0x69, 0x7a );
                encryptor.Key = pdb.GetBytes(32);
                encryptor.IV = pdb.GetBytes(16);
                using MemoryStream ms = new();
                using (CryptoStream cs = new(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
                
                    cs.Write(clearBytes, 0, clearBytes.Length);
                    cs.Close();
                
                icu = Convert.ToBase64String(ms.ToArray());
            
            return icu;
        

【问题讨论】：

你的加密方法怎么样？

字符串太长，无法在此处发表评论，所以我提供了一个 mega.nz 链接 --- mega.nz/file/…

string EncryptionKey = " Bt2a"; 和 string EncryptionKey = "Bt2a";... 这不对。

那是我复制粘贴的错误，但关键是两边都可以（“Bt2a”）。

您提供的代码工作正常，您确定加密值在保存到数据库之前或之后没有改变吗？

【参考方案1】：

我终于设法解决了这个问题。

我忘记声明构造函数“ED = await _context.EncDates.FirstOrDefaultAsync();”在 Decrypt.cshtml.cs 里面 --> OnGetAsync() 这在比较日期字符串时给出了“null”值。

感谢您的帮助。

以下是完整代码。

--- Decrypt.cshtml ---

@if(Model.Decrypt(Model.EncDates.encryptedValue).toString() == Datetime.Today.toString())

正确

否则

错误

--- Decrypt.cshtml.cs ---

...

[BindProperty]
    public EncDate ED  get; set; 
    public IList<EncDate> EDL  get; set; 

    public async Task OnGetAsync()
    
        EDL = await _context.EncDates
            .Include(a => a.Lic).ToListAsync();

        ED = await _context.EncDates.FirstOrDefaultAsync();
    

    public string Decrypt(string cipherText)
    
        string EncryptionKey = "Bt2a";
        cipherText = cipherText.Replace(" ", "+");
        byte[] cipherBytes = Convert.FromBase64String(cipherText);
        using (Aes encryptor = Aes.Create())
        
            Rfc2898DeriveBytes pdb = new(EncryptionKey, new byte[]  0x01, 0x22, 0xcc, 0x0e, 0x50, 0x4d, 0x05, 0xa4, 0x4f, 0xff, 0xe3, 0x69, 0x7a );
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using MemoryStream ms = new();
            using (CryptoStream cs = new(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
            
                cs.Write(cipherBytes, 0, cipherBytes.Length);
                cs.Close();
            
            cipherText = Encoding.Unicode.GetString(ms.ToArray());
        
        return cipherText;
    
    
    public string Encrypt(string icu)
    
        string EncryptionKey = "Bt2a";
        byte[] clearBytes = Encoding.Unicode.GetBytes(icu);
        using (Aes encryptor = Aes.Create())
        
            Rfc2898DeriveBytes pdb = new(EncryptionKey, new byte[]  0x01, 0x22, 0xcc, 0x0e, 0x50, 0x4d, 0x05, 0xa4, 0x4f, 0xff, 0xe3, 0x69, 0x7a );
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);
            using MemoryStream ms = new();
            using (CryptoStream cs = new(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
            
                cs.Write(clearBytes, 0, clearBytes.Length);
                cs.Close();
            
            icu = Convert.ToBase64String(ms.ToArray());
        
        return icu;