78 lines
2.3 KiB
C#
78 lines
2.3 KiB
C#
using System;
|
|
using System.IO;
|
|
|
|
using System.Security.Cryptography;
|
|
using System.Text;
|
|
|
|
namespace Pilz.Cryptography;
|
|
|
|
public class SimpleStringCrypter : ICrypter
|
|
{
|
|
private readonly TripleDES TripleDes;
|
|
public Encoding TextEncoding { get; private set; } = Encoding.Default;
|
|
|
|
public SimpleStringCrypter() : this(string.Empty)
|
|
{
|
|
}
|
|
|
|
public SimpleStringCrypter(string key) : this(key, Encoding.Default)
|
|
{
|
|
}
|
|
|
|
public SimpleStringCrypter(string key, Encoding textEncoding)
|
|
{
|
|
TextEncoding = textEncoding;
|
|
TripleDes = TripleDES.Create();
|
|
TripleDes.Key = TruncateHash(key, TripleDes.KeySize / 8);
|
|
TripleDes.IV = TruncateHash(string.Empty, TripleDes.BlockSize / 8);
|
|
}
|
|
|
|
private byte[] TruncateHash(string key, int length)
|
|
{
|
|
SHA1 sha1CryptoServiceProvider = SHA1.Create();
|
|
var bytes = TextEncoding.GetBytes(key);
|
|
var array = sha1CryptoServiceProvider.ComputeHash(bytes);
|
|
|
|
var output = new byte[length];
|
|
var lowerLength = Math.Min(array.Length, output.Length);
|
|
|
|
for (int i = 0; i < lowerLength; i++)
|
|
output[i] = array[i];
|
|
|
|
return output;
|
|
}
|
|
|
|
private string EncryptData(string plaintext)
|
|
{
|
|
var bytes = TextEncoding.GetBytes(plaintext);
|
|
using var memoryStream = new MemoryStream();
|
|
using var cryptoStream = new CryptoStream(memoryStream, TripleDes.CreateEncryptor(), CryptoStreamMode.Write);
|
|
cryptoStream.Write(bytes, 0, bytes.Length);
|
|
cryptoStream.FlushFinalBlock();
|
|
return Convert.ToBase64String(memoryStream.ToArray());
|
|
}
|
|
|
|
private string DecryptData(string encryptedtext)
|
|
{
|
|
var array = Convert.FromBase64String(encryptedtext);
|
|
using var memoryStream = new MemoryStream();
|
|
using var cryptoStream = new CryptoStream(memoryStream, TripleDes.CreateDecryptor(), CryptoStreamMode.Write);
|
|
cryptoStream.Write(array, 0, array.Length);
|
|
cryptoStream.FlushFinalBlock();
|
|
return TextEncoding.GetString(memoryStream.ToArray());
|
|
}
|
|
|
|
public string Encrypt(string plainValue)
|
|
{
|
|
return EncryptData(plainValue ?? string.Empty);
|
|
}
|
|
|
|
public string Decrypt(string encryptedValue)
|
|
{
|
|
if (string.IsNullOrEmpty(encryptedValue))
|
|
return string.Empty;
|
|
else
|
|
return DecryptData(encryptedValue);
|
|
}
|
|
}
|