任意の長さの (utf8) キーを使用して (utf8) 文字列を暗号化/復号化するために、C# でトリプル DES を使用したいと考えています。
この3つの機能を探しています
public static string Encrypt(string data, string key)
{
...
}
public static string Decrypt(string data, string key)
{
...
}
public static string GenerateKeyFromString(string str)
{
...
}
注: だれかがリンクする前に、http://www.geekzilla.co.uk/view7B360BD8-A77C-4F1F-BCA0-ACD0F6795F61.htmの実装は機能しません。徹底的にテストしました。
私は多くの検索を行い、問題の一部を見つけましEncryptOneBlockたが、他の人にも役立つと思われる完全な「ダミー用」の実装を探しています。
前もって感謝します！
完全なソースはこちら: http://www.codeproject.com/Articles/14150/Encrypt-and-Decrypt-Data-with-C
暗号化:
public static string Encrypt(string toEncrypt, bool useHashing)
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
System.Configuration.AppSettingsReader settingsReader =
new AppSettingsReader();
// Get the key from config file
string key = (string)settingsReader.GetValue("SecurityKey",
typeof(String));
//System.Windows.Forms.MessageBox.Show(key);
//If hashing use get hashcode regards to your key
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//Always release the resources and flush data
// of the Cryptographic service provide. Best Practice
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes.
//We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateEncryptor();
//transform the specified region of bytes array to resultArray
byte[] resultArray =
cTransform.TransformFinalBlock(toEncryptArray, 0,
toEncryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//Return the encrypted data into unreadable string format
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
復号化:
public static string Decrypt(string cipherString, bool useHashing)
{
byte[] keyArray;
//get the byte code of the string
byte[] toEncryptArray = Convert.FromBase64String(cipherString);
System.Configuration.AppSettingsReader settingsReader =
new AppSettingsReader();
//Get your key from config file to open the lock!
string key = (string)settingsReader.GetValue("SecurityKey",
typeof(String));
if (useHashing)
{
//if hashing was used get the hash code with regards to your key
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//release any resource held by the MD5CryptoServiceProvider
hashmd5.Clear();
}
else
{
//if hashing was not implemented get the byte code of the key
keyArray = UTF8Encoding.UTF8.GetBytes(key);
}
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes.
//We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock(
toDecryptArray, 0, toDecryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//return the Clear decrypted TEXT
return UTF8Encoding.UTF8.GetString(resultArray);
}
.Net暗号化ライブラリを使用してみませんか。DESとトリプルDESの実装があります。車輪の再発明をせずにライブラリを使用することをお勧めします。独自の実装を展開するのに最適なスキルよりも、スキルを練習して研ぎ澄ます必要がある場合は、そうですね。:)
private static void EncryptData(String inName, String outName, byte[] tdesKey, byte[] tdesIV)
{
//Create the file streams to handle the input and output files.
FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0);
//Create variables to help with read and write.
byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
long rdlen = 0; //This is the total number of bytes written.
long totlen = fin.Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time.
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, tdes.CreateEncryptor(tdesKey, tdesIV), CryptoStreamMode.Write);
Console.WriteLine("Encrypting...");
//Read from the input file, then encrypt and write to the output file.
while(rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
Console.WriteLine("{0} bytes processed", rdlen);
}
encStream.Close();
}
ソース： MSDN
これは完全な例です。コピーペーストの準備ができています..
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;
namespace MVC3JavaScript_3_2012.Utilities
{
public class MyTripleDES
{
private readonly TripleDESCryptoServiceProvider _des = new TripleDESCryptoServiceProvider();
private readonly UTF8Encoding _utf8 = new UTF8Encoding();
/// <summary>
/// Key to use during encryption and decryption
/// </summary>
private byte[] _keyValue;
public byte[] Key
{
get { return _keyValue; }
private set { _keyValue = value; }
}
/// <summary>
/// Initialization vector to use during encryption and decryption
/// </summary>
private byte[] _ivValue;
public byte[] IV
{
get { return _ivValue; }
private set { _ivValue = value; }
}
/// <summary>
/// Constructor, allows the key and initialization vector to be provided as strings
/// </summary>
/// <param name="key"></param>
/// <param name="iv"></param>
public MyTripleDES(string key, string iv)
{
_keyValue = Convert.FromBase64String(key);
_ivValue = Convert.FromBase64String(iv);
}
/// <summary>
/// Decrypt Bytes
/// </summary>
/// <param name="bytes"></param>
/// <returns></returns>
public byte[] Decrypt(byte[] bytes)
{
return Transform(bytes, _des.CreateDecryptor(_keyValue, _ivValue));
}
/// <summary>
/// Encrypt Bytes
/// </summary>
/// <param name="bytes"></param>
/// <returns></returns>
public byte[] Encrypt(byte[] bytes)
{
return Transform(bytes, _des.CreateEncryptor(_keyValue, _ivValue));
}
/// <summary>
/// Decrypt a string
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public string Decrypt(string text)
{
byte[] input = HttpServerUtility.UrlTokenDecode(text);
byte[] output = Transform(input, _des.CreateDecryptor(_keyValue, _ivValue));
return _utf8.GetString(output);
}
/// <summary>
/// Encrypt a string and return Base64String
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public string Encrypt(string text)
{
byte[] input = _utf8.GetBytes(text);
byte[] output = Transform(input, _des.CreateEncryptor(_keyValue, _ivValue));
return HttpServerUtility.UrlTokenEncode(output);
}
/// <summary>
/// Encrypt or Decrypt bytes.
/// </summary>
private byte[] Transform(byte[] input, ICryptoTransform cryptoTransform)
{
// Create the necessary streams
using (var memory = new MemoryStream())
{
using (var stream = new CryptoStream(memory, cryptoTransform, CryptoStreamMode.Write))
{
// Transform the bytes as requested
stream.Write(input, 0, input.Length);
stream.FlushFinalBlock();
// Read the memory stream and convert it back into byte array
memory.Position = 0;
var result = new byte[memory.Length];
memory.Read(result, 0, result.Length);
// Return result
return result;
}
}
}
public static string CreateNewVector()
{
using (var des = new System.Security.Cryptography.TripleDESCryptoServiceProvider())
{
des.GenerateIV();
return Convert.ToBase64String(des.IV);
}
}
public static string CreateNewKey()
{
using (var des = new System.Security.Cryptography.TripleDESCryptoServiceProvider())
{
des.GenerateKey();
return Convert.ToBase64String(des.Key);
}
}
}
}