c# - 大文件 AES 加密

Question

我需要加密和解密大文件 (~1GB)。我尝试使用这个例子:http://www.codeproject.com/Articles/769741/Csharp-AES-bits-Encryption-Library-with-Salt但我的问题是因为文件非常大，我遇到了 outOfMemory 异常。所以我需要用文件流替换内存流，我只是不知道该怎么做......

(添加我的代码:)

private static void AES_Encrypt(string srcFile, string encryptedFile,  byte[] passwordBytes)
    {


        // Set your salt here, change it to meet your flavor:
        // The salt bytes must be at least 8 bytes.
        byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8};

        FileStream fsInput = new FileStream(srcFile,
            FileMode.Open,
            FileAccess.Read);

        FileStream fsEncrypted = new FileStream(encryptedFile,
                        FileMode.Create,
                        FileAccess.Write);

        using (RijndaelManaged AES = new RijndaelManaged())
        {
            AES.KeySize = 256;
            AES.BlockSize = 128;

            var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
            AES.Key = key.GetBytes(AES.KeySize / 8);
            AES.IV = key.GetBytes(AES.BlockSize / 8);

            AES.Mode = CipherMode.CBC;

            using (var cs = new CryptoStream(fsEncrypted, AES.CreateEncryptor(), CryptoStreamMode.Write))
            {
                byte[] bytearrayinput = new byte[fsInput.Length - 1];
                fsInput.Read(bytearrayinput, 0, bytearrayinput.Length);
                cs.Write(bytearrayinput, 0, bytearrayinput.Length);
                cs.Close();
                fsInput.Flush();
                fsInput.Close();
                fsEncrypted.Close();
            }

        }


    }

    public static void AES_Decrypt(string encryptedFile, string decryptedFile, byte[] passwordBytes)
    {
        byte[] decryptedBytes = null;

        // Set your salt here, change it to meet your flavor:
        // The salt bytes must be at least 8 bytes.
        byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8};

        FileStream fsread = new FileStream(encryptedFile,
                               FileMode.Open,
                               FileAccess.Read);

        using (RijndaelManaged AES = new RijndaelManaged())
        {
            AES.KeySize = 256;
            AES.BlockSize = 128;

            var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
            AES.Key = key.GetBytes(AES.KeySize / 8);
            AES.IV = key.GetBytes(AES.BlockSize / 8);

            AES.Mode = CipherMode.CBC;

            FileStream fsDecrypted = new FileStream(decryptedFile,
                        FileMode.Create,
                        FileAccess.Write);

            using (var cs = new CryptoStream(fsDecrypted, AES.CreateDecryptor(), CryptoStreamMode.Write))
            {
                byte[] bytearrayinput = new byte[fsread.Length - 1];
                fsread.Read(bytearrayinput, 0, bytearrayinput.Length);
                cs.Write(bytearrayinput, 0, bytearrayinput.Length);
                cs.Close();
                fsread.Close();
                fsDecrypted.Close();
            }

        }
    }

Answer 1

最终，这是对我有用的代码:

 private static void AES_Encrypt(string inputFile, string outputFile, byte[] passwordBytes)
 {
        byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8};
        string cryptFile = outputFile;
        FileStream fsCrypt = new FileStream(cryptFile, FileMode.Create);

        RijndaelManaged AES = new RijndaelManaged();

        AES.KeySize = 256;
        AES.BlockSize = 128;


        var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
        AES.Key = key.GetBytes(AES.KeySize / 8);
        AES.IV = key.GetBytes(AES.BlockSize / 8);
        AES.Padding = PaddingMode.Zeros;

        AES.Mode = CipherMode.CBC;

        CryptoStream cs = new CryptoStream(fsCrypt,
             AES.CreateEncryptor(),
            CryptoStreamMode.Write);

        FileStream fsIn = new FileStream(inputFile, FileMode.Open);

        int data;
        while ((data = fsIn.ReadByte()) != -1)
            cs.WriteByte((byte)data);


        fsIn.Close();
        cs.Close();
        fsCrypt.Close();

    }

    private static void AES_Decrypt(string inputFile, string outputFile, byte[] passwordBytes)
    {



        byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8};
        FileStream fsCrypt = new FileStream(inputFile, FileMode.Open);

        RijndaelManaged AES = new RijndaelManaged();

        AES.KeySize = 256;
        AES.BlockSize = 128;


        var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000);
        AES.Key = key.GetBytes(AES.KeySize / 8);
        AES.IV = key.GetBytes(AES.BlockSize / 8);
        AES.Padding = PaddingMode.Zeros;

        AES.Mode = CipherMode.CBC;

        CryptoStream cs = new CryptoStream(fsCrypt,
            AES.CreateDecryptor(),
            CryptoStreamMode.Read);

        FileStream fsOut = new FileStream(outputFile, FileMode.Create);

        int data;
        while ((data = cs.ReadByte()) != -1)
            fsOut.WriteByte((byte)data);

        fsOut.Close();
        cs.Close();
        fsCrypt.Close();

    }
}