Encrypt the string In Typescript And Decrypt In C# using Advanced Encryption Standard Algorithm(AES)

Question

I am having struggle to implement the encryption in typescript and decryption in C#. Before posting question here, I did Google it and find some links but those links are re

Answer 1

npm instal crypto-js

//Inside imports of your TS file include 
import * as CryptoJS from 'crypto-js';

// Declare this key and iv values in declaration
private key = CryptoJS.enc.Utf8.parse('4512631236589784');
private iv = CryptoJS.enc.Utf8.parse('4512631236589784');

// Methods for the encrypt and decrypt Using AES
encryptUsingAES256() {
    var encrypted = CryptoJS.AES.encrypt(CryptoJS.enc.Utf8.parse(JSON.stringify("Your Json Object data or string")), this.key, {
        keySize: 128 / 8,
        iv: this.iv,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.Pkcs7
    });
    console.log('Encrypted :' + encrypted);
    this.decryptUsingAES256(encrypted);
    return encrypted;
}

decryptUsingAES256(decString) {
    var decrypted = CryptoJS.AES.decrypt(decString, this.key, {
        keySize: 128 / 8,
        iv: this.iv,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.Pkcs7
    });
    console.log('Decrypted : ' + decrypted);
    console.log('utf8 = ' + decrypted.toString(CryptoJS.enc.Utf8));

}

The C# code to encode or decode is here.

public class encr {
    public static string DecryptStringAES(string cipherText) {
        var keybytes = Encoding.UTF8.GetBytes("4512631236589784");
        var iv = Encoding.UTF8.GetBytes("4512631236589784");

        var encrypted = Convert.FromBase64String(cipherText);
        var decriptedFromJavascript = DecryptStringFromBytes(encrypted, keybytes, iv);
        return decriptedFromJavascript;
    }
    private static string DecryptStringFromBytes(byte[] cipherText, byte[] key, byte[] iv) {
        // Check arguments.
        if (cipherText == null || cipherText.Length <= 0) {
            throw new ArgumentNullException("cipherText");
        }
        if (key == null || key.Length <= 0) {
            throw new ArgumentNullException("key");
        }
        if (iv == null || iv.Length <= 0) {
            throw new ArgumentNullException("key");
        }

        // Declare the string used to hold
        // the decrypted text.
        string plaintext = null;

        // Create an RijndaelManaged object
        // with the specified key and IV.
        using(var rijAlg = new RijndaelManaged()) {
            //Settings
            rijAlg.Mode = CipherMode.CBC;
            rijAlg.Padding = PaddingMode.PKCS7;
            rijAlg.FeedbackSize = 128;

            rijAlg.Key = key;
            rijAlg.IV = iv;

            // Create a decrytor to perform the stream transform.
            var decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

            try {
                // Create the streams used for decryption.
                using(var msDecrypt = new MemoryStream(cipherText)) {
                    using(var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) {

                        using(var srDecrypt = new StreamReader(csDecrypt)) {
                            // Read the decrypted bytes from the decrypting stream
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();

                        }

                    }
                }
            } catch {
                plaintext = "keyError";
            }
        }

        return plaintext;
    }

    public static string EncryptStringAES(string plainText) {
        var keybytes = Encoding.UTF8.GetBytes("4512631236589784");
        var iv = Encoding.UTF8.GetBytes("4512631236589784");

        var encryoFromJavascript = EncryptStringToBytes(plainText, keybytes, iv);
        return Convert.ToBase64String(encryoFromJavascript);
    }

    private static byte[] EncryptStringToBytes(string plainText, byte[] key, byte[] iv) {
        // Check arguments.
        if (plainText == null || plainText.Length <= 0) {
            throw new ArgumentNullException("plainText");
        }
        if (key == null || key.Length <= 0) {
            throw new ArgumentNullException("key");
        }
        if (iv == null || iv.Length <= 0) {
            throw new ArgumentNullException("key");
        }
        byte[] encrypted;
        // Create a RijndaelManaged object
        // with the specified key and IV.
        using(var rijAlg = new RijndaelManaged()) {
            rijAlg.Mode = CipherMode.CBC;
            rijAlg.Padding = PaddingMode.PKCS7;
            rijAlg.FeedbackSize = 128;

            rijAlg.Key = key;
            rijAlg.IV = iv;

            // Create a decrytor to perform the stream transform.
            var encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

            // Create the streams used for encryption.
            using(var msEncrypt = new MemoryStream()) {
                using(var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) {
                    using(var swEncrypt = new StreamWriter(csEncrypt)) {
                        //Write all data to the stream.
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }
        // Return the encrypted bytes from the memory stream.
        return encrypted;
    }
}