add Pilz.Cryptography

Pilz.Cryptography/SimpleStringCrypter.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Security.Cryptography;
+using System.IO;
+using Microsoft.VisualBasic.CompilerServices;
+
+namespace Pilz.Cryptography
+{
+    public class SimpleStringCrypter : ICrypter
+    {
+        private TripleDESCryptoServiceProvider 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 = new TripleDESCryptoServiceProvider();
+            TripleDes.Key = TruncateHash(key,TripleDes.KeySize / 8);
+            TripleDes.IV = TruncateHash(string.Empty, TripleDes.BlockSize / 8);
+        }
+
+        private byte[] TruncateHash(string key, int length)
+        {
+            SHA1CryptoServiceProvider sha1CryptoServiceProvider = new SHA1CryptoServiceProvider();
+            byte[] bytes = TextEncoding.GetBytes(key);
+            byte[] array = sha1CryptoServiceProvider.ComputeHash(bytes);
+            return (byte[])Utils.CopyArray(array, new byte[checked(length - 1 + 1)]);
+        }
+
+        private string EncryptData(string plaintext)
+        {
+            byte[] bytes = TextEncoding.GetBytes(plaintext);
+            MemoryStream memoryStream = new MemoryStream();
+            CryptoStream 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)
+        {
+            byte[] array = Convert.FromBase64String(encryptedtext);
+            MemoryStream memoryStream = new MemoryStream();
+            CryptoStream 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);
+        }
+
+        public string Decrypt(string encryptedValue)
+        {
+            if (string.IsNullOrEmpty(encryptedValue))
+                return string.Empty;
+            else
+                return DecryptData(encryptedValue);
+        }
+    }
+}