如何解密AES-256-CBC加密字符串

我是C＃的新手，我真的需要帮助。 我需要在C＃中使用AES-256-CBC加密/解密字符串，我发现这是为了加密字符串：

public static string EncryptString(string message, string KeyString, string IVString) { byte[] Key = ASCIIEncoding.UTF8.GetBytes(KeyString); byte[] IV = ASCIIEncoding.UTF8.GetBytes(IVString); string encrypted = null; RijndaelManaged rj = new RijndaelManaged(); rj.Key = Key; rj.IV = IV; rj.Mode = CipherMode.CBC; try { MemoryStream ms = new MemoryStream(); using (CryptoStream cs = new CryptoStream(ms, rj.CreateEncryptor(Key, IV), CryptoStreamMode.Write)) { using (StreamWriter sw = new StreamWriter(cs)) { sw.Write(message); sw.Close(); } cs.Close(); } byte[] encoded = ms.ToArray(); encrypted = Convert.ToBase64String(encoded); ms.Close(); } catch (CryptographicException e) { Console.WriteLine("A Cryptographic error occurred: {0}", e.Message); return null; } catch (UnauthorizedAccessException e) { Console.WriteLine("A file error occurred: {0}", e.Message); return null; } catch (Exception e) { Console.WriteLine("An error occurred: {0}", e.Message); } finally { rj.Clear(); } return encrypted; } 

我尝试根据上面的代码编写一个解密函数，下面的代码是我做的：

  // Decrypt a byte array into a byte array using a key and an IV private byte[] Decrypt(byte[] cipherData, byte[] Key, byte[] IV) { byte[] decryptedData; //string plaintext = null; //MemoryStream ms = new MemoryStream(cipherData); RijndaelManaged alg = new RijndaelManaged(); alg.KeySize = 256; alg.BlockSize = 128; alg.Key = Key; alg.IV = IV; alg.Mode = CipherMode.CBC; alg.Padding = PaddingMode.Zeros; //Array.Copy(Key, 0, IV, 0, IV.Length); ICryptoTransform decryptor = alg.CreateDecryptor(alg.Key, alg.IV); using(MemoryStream ms = new MemoryStream(cipherData)) { using (CryptoStream csDecrypt = new CryptoStream(ms, decryptor, CryptoStreamMode.Read)) { using (StreamReader sw = new StreamReader(csDecrypt)) { sw.ReadToEnd(); sw.Close(); } csDecrypt.Close(); decryptedData = ms.ToArray(); } } //byte[] decryptedData = System.Text.Encoding.Unicode.GetBytes(plaintext); return decryptedData; } 

但这是无稽之谈，它无法解密任何东西。 我真的很困惑，需要帮助。 感谢您的任何帮助！

P / s：请不要给我其他类似的回答问题，我已经看过了。 它们的加密function与上述加密function不具有相同的输出，而我需要解密必须由上述function加密的字符串。 我有两个用PHP编写解密函数的朋友和Objective-C，它与上面的加密函数相匹配，让他们再做一次是不好的。

Answer 1

看看你的加密，这样的事情应该这样做，从你的加密传递结果字符串应该给回原始字符串;

 // Decrypt a string into a string using a key and an IV public static string Decrypt(string cipherData, string keyString, string ivString) { byte[] key = Encoding.UTF8.GetBytes(keyString); byte[] iv = Encoding.UTF8.GetBytes(ivString); try { using (var rijndaelManaged = new RijndaelManaged {Key = key, IV = iv, Mode = CipherMode.CBC}) using (var memoryStream = new MemoryStream(Convert.FromBase64String(cipherData))) using (var cryptoStream = new CryptoStream(memoryStream, rijndaelManaged.CreateDecryptor(key, iv), CryptoStreamMode.Read)) { return new StreamReader(cryptoStream).ReadToEnd(); } } catch (CryptographicException e) { Console.WriteLine("A Cryptographic error occurred: {0}", e.Message); return null; } // You may want to catch more exceptions here... } 

小记; 你使用密钥字符串中的UTF8编码获取密钥，UTF8编码可能会为国际字符提供多个字节，这可能会给密钥或IV加密/解密的长度错误。 此外，使用8个字符和可打印字符的小范围密码/密钥将无法为您提供非常安全的加密，您可能希望在将其用作密钥之前通过SHA1或类似字符串运行该字符串（这将令人遗憾地使其与当前加密）