Create Crypt.cs

ADDED: New Crypt.cs

Crypt.cs

@@ -0,0 +1,77 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Security.Cryptography;
+using System.Globalization;
+
+namespace App.Opayo
+{
+    public static class Crypt
+    {
+        public static string Encrypt(string input, string password)
+        {
+            return ByteArrayToHexString(AesEncrypt(Encoding.UTF8.GetBytes(input), password));
+        }
+
+        public static string Decrypt(string input, string password)
+        {
+            return Encoding.UTF8.GetString(AESdecrypt(ConvertHexStringToByteArray(input.Replace("@", "")), password));
+        }
+
+        private static byte[] ConvertHexStringToByteArray(string hexString)
+        {
+            if (hexString.Length % 2 != 0)
+            {
+                throw new ArgumentException("Binary key must have even number of digits");
+            }
+
+            byte[] data = new byte[hexString.Length / 2];
+
+            for (int index = 0; index < data.Length; index++)
+            {
+                string byteValue = hexString.Substring(index * 2, 2);
+                data[index] = byte.Parse(byteValue, NumberStyles.HexNumber, CultureInfo.InvariantCulture);
+            }
+
+            return data;
+        }
+
+        private static string ByteArrayToHexString(byte[] value)
+        {
+            return BitConverter.ToString(value).Replace("-", "");
+        }
+
+        private static byte[] AesEncrypt(byte[] input, string key)
+        {
+            using MemoryStream ms = new MemoryStream();
+            var aes = GetAesManagedEncryption(key);
+            CryptoStream cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write);
+            cs.Write(input, 0, input.Length);
+            cs.FlushFinalBlock();
+            return ms.ToArray();
+        }
+
+        private static byte[] AESdecrypt(byte[] input, string key)
+        {
+            using MemoryStream ms = new MemoryStream();
+            var aes = GetAesManagedEncryption(key);
+            CryptoStream cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Write);
+            cs.Write(input, 0, input.Length);
+            cs.FlushFinalBlock();
+            return ms.ToArray();
+        }
+
+        private static AesManaged GetAesManagedEncryption(string key)
+        {
+            return new AesManaged
+            {
+                Padding = PaddingMode.PKCS7,
+                Mode = CipherMode.CBC,
+                KeySize = 128,
+                BlockSize = 128,
+                Key = Encoding.UTF8.GetBytes(key),
+                IV = Encoding.UTF8.GetBytes(key)
+            };
+        }
+    }
+}