encrypt decrypt string in asp.net Core

This article is all about Implementing Simple AES encryption decryption algorithm in Asp.net Core.

We can actually use the same code for .net framework 4.7.2 also.

Use using System.Security.Cryptography;
Just make sure the key which we use for encryption and decryption is same. In our case we are using following key (This key I have copied from some references I already have.)

private static string keyString = "E546C8DF278CD5931069B522E695D4F2";

For encryption use following function, I generally keep Helper functions as static function

public static string EncryptString(string text)
        {
            var key = Encoding.UTF8.GetBytes(keyString);

            using (var aesAlg = Aes.Create())
            {
                using (var encryptor = aesAlg.CreateEncryptor(key, aesAlg.IV))
                {
                    using (var msEncrypt = new MemoryStream())
                    {
                        using (var csEncrypt = new CryptoStream(msEncrypt, 
encryptor, CryptoStreamMode.Write))
                        using (var swEncrypt = new StreamWriter(csEncrypt))
                        {
                            swEncrypt.Write(text);
                        }

      var iv = aesAlg.IV;
      var decryptedContent = msEncrypt.ToArray();
      var result = new byte[iv.Length + decryptedContent.Length];
      Buffer.BlockCopy(iv, 0, result, 0, iv.Length);
      Buffer.BlockCopy(decryptedContent, 0, result, iv.Length,
     decryptedContent.Length);

                        return Convert.ToBase64String(result);
                    }
                }
            }
        }

For decryption use following function

public static string DecryptString(string cipherText)
        {
            var fullCipher = Convert.FromBase64String(cipherText);

            var iv = new byte[16];
            var cipher = new byte[16];

            Buffer.BlockCopy(fullCipher, 0, iv, 0, iv.Length);
            Buffer.BlockCopy(fullCipher, iv.Length, cipher, 0, iv.Length);
            var key = Encoding.UTF8.GetBytes(keyString);

            using (var aesAlg = Aes.Create())
            {
                using (var decryptor = aesAlg.CreateDecryptor(key, iv))
                {
                    string result;
                    using (var msDecrypt = new MemoryStream(cipher))
                    {
                        using (var csDecrypt = new CryptoStream(msDecrypt,
 decryptor, CryptoStreamMode.Read))
                        {
                            using (var srDecrypt = new StreamReader(csDecrypt))
                            {
                                result = srDecrypt.ReadToEnd();
                            }
                        }
                    }

                    return result;
                }
            }
        }