暗号化されたイメージをSqlサーバーデータベースに格納する方法

Question

自分のイメージを自分のSQL Serverデータベースに保存したいが、セキュリティとプライバシーの理由から、私はそれらを暗号化された形式で保存したい。

これを行うにはどうすればよいですか？

また、画像を暗号化して復号化して取得する方法もありますか？

実際に私は暗号化方法を知っていますが、私の質問は、画像を暗号化しながらデータベースに画像を保存する方法を使用することです。

Answer 1

System.Security.Cryptography名前空間を使用できます。このpageは、このためのC＃の例を持っています

using System; 
using System.IO; 
using System.Security.Cryptography; 

namespace Aes_Example 
{ 
    class AesExample 
    { 
     public static void Main() 
     { 
      try 
      { 

       string original = "Here is some data to encrypt!"; 

       // Create a new instance of the AesManaged 
       // class. This generates a new key and initialization 
       // vector (IV). 
       using (AesManaged myAes = new AesManaged()) 
       { 

        // Encrypt the string to an array of bytes. 
        byte[] encrypted = EncryptStringToBytes_Aes(original, myAes.Key, myAes.IV); 

        // Decrypt the bytes to a string. 
        string roundtrip = DecryptStringFromBytes_Aes(encrypted, myAes.Key, myAes.IV); 

        //Display the original data and the decrypted data. 
        Console.WriteLine("Original: {0}", original); 
        Console.WriteLine("Round Trip: {0}", roundtrip); 
       } 

      } 
      catch (Exception e) 
      { 
       Console.WriteLine("Error: {0}", e.Message); 
      } 
     } 
     static byte[] EncryptStringToBytes_Aes(string plainText, byte[] Key, byte[] IV) 
     { 
      // Check arguments. 
      if (plainText == null || plainText.Length <= 0) 
       throw new ArgumentNullException("plainText"); 
      if (Key == null || Key.Length <= 0) 
       throw new ArgumentNullException("Key"); 
      if (IV == null || IV.Length <= 0) 
       throw new ArgumentNullException("IV"); 
      byte[] encrypted; 
      // Create an AesManaged object 
      // with the specified key and IV. 
      using (AesManaged aesAlg = new AesManaged()) 
      { 
       aesAlg.Key = Key; 
       aesAlg.IV = IV; 

       // Create a decrytor to perform the stream transform. 
       ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV); 

       // Create the streams used for encryption. 
       using (MemoryStream msEncrypt = new MemoryStream()) 
       { 
        using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) 
        { 
         using (StreamWriter swEncrypt = new StreamWriter(csEncrypt)) 
         { 

          //Write all data to the stream. 
          swEncrypt.Write(plainText); 
         } 
         encrypted = msEncrypt.ToArray(); 
        } 
       } 
      } 


      // Return the encrypted bytes from the memory stream. 
      return encrypted; 

     } 

     static string DecryptStringFromBytes_Aes(byte[] cipherText, byte[] Key, byte[] IV) 
     { 
      // Check arguments. 
      if (cipherText == null || cipherText.Length <= 0) 
       throw new ArgumentNullException("cipherText"); 
      if (Key == null || Key.Length <= 0) 
       throw new ArgumentNullException("Key"); 
      if (IV == null || IV.Length <= 0) 
       throw new ArgumentNullException("IV"); 

      // Declare the string used to hold 
      // the decrypted text. 
      string plaintext = null; 

      // Create an AesManaged object 
      // with the specified key and IV. 
      using (AesManaged aesAlg = new AesManaged()) 
      { 
       aesAlg.Key = Key; 
       aesAlg.IV = IV; 

       // Create a decrytor to perform the stream transform. 
       ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV); 

       // Create the streams used for decryption. 
       using (MemoryStream msDecrypt = new MemoryStream(cipherText)) 
       { 
        using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) 
        { 
         using (StreamReader srDecrypt = new StreamReader(csDecrypt)) 
         { 

          // Read the decrypted bytes from the decrypting stream 
          // and place them in a string. 
          plaintext = srDecrypt.ReadToEnd(); 
         } 
        } 
       } 

      } 

      return plaintext; 

     } 
    } 
}