bykovme/nswallet

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

namespace NSWallet.Shared
{
    // FIXME: Remove this method as soon as possible
    public  static partial class Security
    {
        public static string DecryptStringAES_IOS(byte[] encryptedData, string password, int reEncryptionCount, string hash, out bool ok)
        {
            ok = false;

            var key = prepareKey(password, hash, reEncryptionCount);
            byte[] decryptedData;
            key[0] = 0;

            try {
                using (MemoryStream ms = new MemoryStream()) {
                    using (AesManaged myAes = new AesManaged()) {
                        myAes.Mode = CipherMode.CBC;
                        myAes.Padding = PaddingMode.PKCS7;
                        myAes.Key = key;
                        myAes.IV = new byte[16] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };


                        using (var cs = new CryptoStream(ms, myAes.CreateDecryptor(), CryptoStreamMode.Write)) {
                            cs.Write(encryptedData, 0, encryptedData.Length);
                            cs.Close();
                        }
                        decryptedData = ms.ToArray();
                    }
                }

                /*
                ISymmetricKeyAlgorithmProvider aes = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
                ICryptographicKey symetricKey = aes.CreateSymmetricKey(key);
                var bytes = WinRTCrypto.CryptographicEngine.Decrypt(symetricKey, encryptedData);
                */
                var resultText = Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);

                if (resultText.Length < KEY_LENGTH)
                    return "";

                var md5 = resultText.Substring(0, KEY_LENGTH);
                var fullStr = resultText.Substring(KEY_LENGTH);
                if (md5 == CalcMD5(fullStr)) {
                    ok = true;
                    return fullStr;
                }
            } catch (Exception ex) {
                log(ex.Message, nameof(DecryptStringAES));
                ok = false;
            }

            return "";
        }
    }
}