Encrypt and Decrypt

Jaya Prakash

I should do Encrypt and Decrypt this json object i dont know how to do what should i take pls help me out...

i should take two textboxes one for encrypt and another for decrypt in ecrypt txtbox i should enter this json object how to do it..

how to enter json object into a textbox pls help me

{
id:,
mobile:,
name :"",
lname:"",
date:"",
gender:"",
salary:"",
location:""
}

3 Replies

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Naimish Makwana3y ago

Accepted answer

Hello Jaya,

First, you need to convert the jsonObject to a JSON string. Use Newtonsoft.Json package for that.

using Newtonsoft.Json;

// ...

var jsonObject = new {
    id = 1,
    mobile = "1234567890",
    name = "John",
    lname = "Doe",
    date = "2023-03-15",
    gender = "Male",
    salary = 50000,
    location = "New York"
};

string jsonString = JsonConvert.SerializeObject(jsonObject);

Then you can use the AesCryptoServiceProvider class to encrypt and decrypt the string.

example of how you can encrypt the JSON string:

using System.Security.Cryptography;
using System.Text;

// ...

string key = "mySecretKey1234567890"; // the encryption key
byte[] keyBytes = Encoding.UTF8.GetBytes(key);

using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider()) {
    aes.Key = keyBytes;
    aes.GenerateIV();

    byte[] inputBytes = Encoding.UTF8.GetBytes(jsonString);
    byte[] encryptedBytes;

    using (ICryptoTransform encryptor = aes.CreateEncryptor()) {
        encryptedBytes = encryptor.TransformFinalBlock(inputBytes, 0, inputBytes.Length);
    }

    string encryptedString = Convert.ToBase64String(aes.IV.Concat(encryptedBytes).ToArray());

    // Now you can display the encrypted string in the encrypt textbox
    encryptTextBox.Text = encryptedString;
}

To decrypt the encrypted string, you can use the following code:

using System.Security.Cryptography;

// ...

string encryptedString = encryptTextBox.Text;

byte[] encryptedBytes = Convert.FromBase64String(encryptedString);
byte[] ivBytes = encryptedBytes.Take(16).ToArray(); // first 16 bytes are the IV
byte[] encryptedDataBytes = encryptedBytes.Skip(16).ToArray(); // the rest is the encrypted data

string key = "mySecretKey1234567890"; // the encryption key
byte[] keyBytes = Encoding.UTF8.GetBytes(key);

using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider()) {
    aes.Key = keyBytes;
    aes.IV = ivBytes;

    byte[] decryptedBytes;

    using (ICryptoTransform decryptor = aes.CreateDecryptor()) {
        decryptedBytes = decryptor.TransformFinalBlock(encryptedDataBytes, 0, encryptedDataBytes.Length);
    }

    string decryptedString = Encoding.UTF8.GetString(decryptedBytes);

    // Now you can display the decrypted string in the decrypt textbox
    decryptTextBox.Text = decryptedString;
}

Thanks

Naimish Makwana

Jaya Prakash3y ago
getting error like this i tried but none worked out...

Amit Mohanty3y ago

Check this

public static class StringCipher
{
    private const int Keysize = 256;
    // This constant determines the number of iterations for the password bytes generation function.
    private const int DerivationIterations = 1000;
    public static string passPhrase = "secretkey";
    public static string Encrypt(string plainText)
    {
        // Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
        // so that the same Salt and IV values can be used when decrypting.  
        var saltStringBytes = Generate256BitsOfRandomEntropy();
        var ivStringBytes = Generate256BitsOfRandomEntropy();
        var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
        using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
        {
            var keyBytes = password.GetBytes(Keysize / 8);
            using (var symmetricKey = new RijndaelManaged())
            {
                symmetricKey.BlockSize = 256;
                symmetricKey.Mode = CipherMode.CBC;
                symmetricKey.Padding = PaddingMode.PKCS7;
                using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))
                {
                    using (var memoryStream = new MemoryStream())
                    {
                        using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
                        {
                            cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
                            cryptoStream.FlushFinalBlock();
                            // Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.
                            var cipherTextBytes = saltStringBytes;
                            cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();
                            cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
                            memoryStream.Close();
                            cryptoStream.Close();
                            return Convert.ToBase64String(cipherTextBytes);
                        }
                    }
                }
            }
        }
    }

    public static string Decrypt(string cipherText)
    {
        if (cipherText == null)
        {
            return null;
        }
        else
        {
            // Get the complete stream of bytes that represent:
            // [32 bytes of Salt] + [32 bytes of IV] + [n bytes of CipherText]
            var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);
            // Get the saltbytes by extracting the first 32 bytes from the supplied cipherText bytes.
            var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
            // Get the IV bytes by extracting the next 32 bytes from the supplied cipherText bytes.
            var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
            // Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
            var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
            using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
            {
                var keyBytes = password.GetBytes(Keysize / 8);
                using (var symmetricKey = new RijndaelManaged())
                {
                    symmetricKey.BlockSize = 256;
                    symmetricKey.Mode = CipherMode.CBC;
                    symmetricKey.Padding = PaddingMode.PKCS7;
                    using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))
                    {
                        using (var memoryStream = new MemoryStream(cipherTextBytes))
                        {
                            using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
                            {
                                var plainTextBytes = new byte[cipherTextBytes.Length];
                                var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
                                memoryStream.Close();
                                cryptoStream.Close();
                                return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
                            }
                        }
                    }
                }
            }
        }
    }

    private static byte[] Generate256BitsOfRandomEntropy()
    {
        var randomBytes = new byte[32]; // 32 Bytes will give us 256 bits.
        using (var rngCsp = new RNGCryptoServiceProvider())
        {
            // Fill the array with cryptographically secure random bytes.
            rngCsp.GetBytes(randomBytes);
        }
        return randomBytes;
    }
}

How to use

var person = new { Name = "John Doe", Age = 30, Email = "[email protected]" };
string jsonData = JsonConvert.SerializeObject(person);
string encryptedJson = StringCipher.Encrypt(person.ToString());
var decryptedPerson = StringCipher.Decrypt(encryptedJson);