0

だからここに私の混乱があります。ランダムなUnicode文字を返します。両方のメソッドに同じキーと同じIVを使用し、両方に同じエンコーディングを使用しています。ランダム応答の原因は何ですか？

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

namespace FileFish
{
    class Program
    {
        public static void Main()
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            aes.GenerateIV();
            Console.WriteLine(Decrypt(Encoding.UTF8.GetBytes("APPLEAPPLEAPPLEAPPLEAPPLEAPPLEAP"), aes.IV, Encrypt(Encoding.UTF8.GetBytes("APPLEAPPLEAPPLEAPPLEAPPLEAPPLEAP"), aes.IV, "cheese")));
            Console.ReadKey(true);
        }

        private static byte[] Encrypt(byte[] key, byte[] iv, string plaintext)
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            aes.Key = key;
            aes.IV = iv;
            ICryptoTransform encryptor = aes.CreateEncryptor();
            MemoryStream ms = new MemoryStream();
            StreamWriter sw = new StreamWriter(new CryptoStream(ms, encryptor, CryptoStreamMode.Write));
            sw.Write(plaintext);
            return ms.ToArray();
        }

        private static string Decrypt(byte[] key, byte[] iv, byte[] ciphertext)
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            aes.Key = key;
            aes.IV = iv;
            ICryptoTransform decryptor = aes.CreateEncryptor();
            MemoryStream ms = new MemoryStream(ciphertext);
            StreamReader sr = new StreamReader(new CryptoStream(ms, decryptor, CryptoStreamMode.Read));
            return sr.ReadToEnd();
        }
    }
}
4

2 に答える 2

0

Encryptメソッドが空の配列を返すため、コードサンプルは失敗します。自分で転がそうとするよりも、うまくいくことが証明されているものを使うほうがよいでしょう。

AesCryptoServiceProviderドキュメントの例は、サンプルコードのメソッドEncryptとメソッドの代わりに機能します。Decrypt

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("Key");
    byte[] encrypted;
    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
    {
        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("Key");

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

    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
    {
        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;
}
于 2012-03-11T23:24:19.123 に答える
0

また、この問題の原因ではありませんが、http: //blogs.msdn.com/b/shawnfa/archive/2005/11/10/491431.aspx

文字列エンコーディングを介して暗号文をラウンドトリップしない

于 2012-03-11T23:56:25.080 に答える