How to generate AES/CBC/PKCS5Padding encrypted cipher in angularJs

Question

I am working on a feature which require Aes encrypted (AES/CBC/PKCS5padding) cipher text to be sent from client to server which has ASP.Net in backend.

I've a decryption function on the server side as below :

 public static string Decrypt(string inputBase64, string passphrase = null)
                {
                    byte[] key, iv = new byte[0];
                    byte[] base64data = Convert.FromBase64String(inputBase64);
                    byte[] passphrasedata = RawBytesFromString(passphrase);
                    byte[] currentHash = new byte[0];
                    SHA256Managed hash = new SHA256Managed();
                    currentHash = hash.ComputeHash(passphrasedata);
                    return DecryptStringFromBytes(base64data, currentHash, null);
                }



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 cipher = new RijndaelManaged())
            {
                cipher.Key = Key;
                cipher.IV = new byte[16];
                //cipher.Mode = CipherMode.CBC;
                //cipher.Padding = PaddingMode.PKCS7;

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

                // Create the streams used for decryption. 
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        var bytes = default(byte[]);
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            bytes = srDecrypt.CurrentEncoding.GetBytes(srDecrypt.ReadToEnd());

                            // Read the decrypted bytes from the decrypting stream 
                            // and place them in a string.
                            //aintext = srDecrypt.ReadToEnd();
                        }
                        plaintext = ASCIIEncoding.UTF8.GetString(bytes, 0, bytes.Count());
                    }
                }

            }

            return plaintext;

        }

I want to implement an angularjs alternative to the following android code :

public static String Encrypt(String input, String passphrase)
    {
        if (input.equalsIgnoreCase("") || passphrase.equalsIgnoreCase(""))
            return "";
        else
        {
            byte[] key, iv;

            byte[] passphrasedata = null;
            try
            {
                passphrasedata = passphrase.getBytes("UTF-8");
            }
            catch (UnsupportedEncodingException e1)
            {
                e1.printStackTrace();
            }
            byte[] currentHash = new byte[0];
            MessageDigest md = null;
            try
            {
                md = MessageDigest.getInstance("SHA-256");
            }
            catch (NoSuchAlgorithmException e)
            {
                e.printStackTrace();
            }
            currentHash = md.digest(passphrasedata);

            iv = new byte[16];
            return Base64.encodeToString(EncryptStringToBytes(input, currentHash, iv), Base64.NO_WRAP);
        }
    }

static byte[] EncryptStringToBytes(String plainText, byte[] Key, byte[] IV)
    {
        if (plainText == null || plainText.length() <= 0)
        {
            Log.e("error", "plain text empty");
        }
        if (Key == null || Key.length <= 0)
        {
            Log.e("error", "key is empty");
        }
        if (IV == null || IV.length <= 0)
        {
            Log.e("error", "IV key empty");
        }
        byte[] encrypted;

        try
        {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            SecretKeySpec myKey = new SecretKeySpec(Key, "AES");
            IvParameterSpec IVKey = new IvParameterSpec(IV);
            cipher.init(Cipher.ENCRYPT_MODE, myKey, IVKey);

            encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
            return encrypted;
        }
        catch (InvalidKeyException e)
        {
            e.printStackTrace();
        }
        catch (NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        catch (NoSuchPaddingException e)
        {
            e.printStackTrace();
        }
        catch (InvalidAlgorithmParameterException e)
        {
            e.printStackTrace();
        }
        catch (IllegalBlockSizeException e)
        {
            e.printStackTrace();
        }
        catch (BadPaddingException e)
        {
            e.printStackTrace();
        }
        catch (UnsupportedEncodingException e)
        {
            e.printStackTrace();
        }
        return null;
    }

The Android code above is working fine. I want to implement the same encryption logic at AngularJs.

I've included CryptoJS library for SHA-256 and AES cipher calculation. Here is the code which I've implemented.

var password = '12345678';
var passwordHash = CryptoJS.SHA256(password).toString(CryptoJS.enc.Latin1);
var iv = CryptoJS.enc.Hex.parse('0000000000000000');                                                                       
var cipher = CryptoJS.AES.encrypt(plaintext,passwordHash,{
                            iv: iv,
                            mode: CryptoJS.mode.CBC,
                            keySize: 256/32,
                            padding: CryptoJS.pad.Pkcs7
                            });
cipherText = cipher.ciphertext.toString(CryptoJS.enc.Base64);

The problem is that, the encoded string cannot be decrypted back to its previous form. I think there is some mismatch in the encryption logic in the client side and decryption logic on the server side.

When I pass the CryptoJS encrypted cipher to java decryption function, it shows errors:

javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher

or sometimes:

javax.crypto.BadPaddingException: Given final block not properly padded

Answer 1

Thanks guys!!!, I got it working with the following code.

    function hash (){
       return CryptoJS.SHA256(password);
    }
    var cipher = (function(plaintext, password) {
                        passwordHash = hash(password);
                        var iv = CryptoJS.enc.Hex.parse('0000000000000000');
                        var cipher = CryptoJS.AES.encrypt(plaintext, passwordHash, {
                            iv: iv,
                            mode: CryptoJS.mode.CBC,
                            keySize: 256 / 32,
                            padding: CryptoJS.pad.Pkcs7
                        });
                        return cipher;
    })(plaintext, password);

   cipherBase64 =  cipher.ciphertext.toString().hex2a().base64Encode();