John Davidson

Message:

C#

 public void start()

 {

   Constants.APIENCRYPTKEY = Convert.ToBase64String(Encoding.Default.GetBytes(Session(32)));

   Constants.APIENCRYPTSALT = Convert.ToBase64String(Encoding.Default.GetBytes(Session(16)));

   string results = EncryptService("start");

 }

  private static string Session(int length)

        {

            Random random = new Random();

            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";

            return new string(Enumerable.Repeat(chars, length)

             .Select(s => s[random.Next(s.Length)]).ToArray());

        }



 public static string DecryptService(string value)

        {

            string message = value;

            string password = Encoding.Default.GetString(Convert.FromBase64String(Constants.APIENCRYPTKEY));

            SHA256 mySHA256 = SHA256Managed.Create();

            byte[] key = mySHA256.ComputeHash(Encoding.ASCII.GetBytes(password));

            byte[] iv = Encoding.ASCII.GetBytes(Encoding.Default.GetString(Convert.FromBase64String(Constants.APIENCRYPTSALT)));



            string decrypted = DecryptString(message, key, iv);

            return decrypted;

        }



 public static string DecryptString(string cipherText, byte[] key, byte[] iv)

        {

            Aes encryptor = Aes.Create();

            encryptor.Mode = CipherMode.CBC;

            encryptor.Key = key;

            encryptor.IV = iv;

            MemoryStream memoryStream = new MemoryStream();

            ICryptoTransform aesDecryptor = encryptor.CreateDecryptor();

            CryptoStream cryptoStream = new CryptoStream(memoryStream, aesDecryptor, CryptoStreamMode.Write);

            string plainText = String.Empty;

            try

            {

                byte[] cipherBytes = Convert.FromBase64String(cipherText);

                cryptoStream.Write(cipherBytes, 0, cipherBytes.Length);

                cryptoStream.FlushFinalBlock();

                byte[] plainBytes = memoryStream.ToArray();

                plainText = Encoding.ASCII.GetString(plainBytes, 0, plainBytes.Length);

            }

            finally

            {

                memoryStream.Close();

                cryptoStream.Close();

            }

            return plainText;

        }



 public static string EncryptService(string value)

        {

            string message = value;

            string password = Encoding.Default.GetString(Convert.FromBase64String(Constants.APIENCRYPTKEY));

            SHA256 mySHA256 = SHA256Managed.Create();

            byte[] key = mySHA256.ComputeHash(Encoding.ASCII.GetBytes(password));

            byte[] iv = Encoding.ASCII.GetBytes(Encoding.Default.GetString(Convert.FromBase64String(Constants.APIENCRYPTSALT)));

            string encrypted = EncryptString(message, key, iv);

            int property = Int32.Parse((OnProgramStart.AID.Substring(0, 2)));

            string final = encrypted + Security.Obfuscate(property);

            return final;

        }



  public static string EncryptString(string plainText, byte[] key, byte[] iv)

        {

            Aes encryptor = Aes.Create();

            encryptor.Mode = CipherMode.CBC;

            encryptor.Key = key;

            encryptor.IV = iv;

            MemoryStream memoryStream = new MemoryStream();

            ICryptoTransform aesEncryptor = encryptor.CreateEncryptor();

            CryptoStream cryptoStream = new CryptoStream(memoryStream, aesEncryptor, CryptoStreamMode.Write);

            byte[] plainBytes = Encoding.ASCII.GetBytes(plainText);

            cryptoStream.Write(plainBytes, 0, plainBytes.Length);

            cryptoStream.FlushFinalBlock();

            byte[] cipherBytes = memoryStream.ToArray();

            memoryStream.Close();

            cryptoStream.Close();

            string cipherText = Convert.ToBase64String(cipherBytes, 0, cipherBytes.Length);

            return cipherText;

        }

This is what I got so far in PHP

function decrypt_string($msg='', $salt='', $key='')

{

                

                        $key =  utf8_encode(base64_decode($key));  

                        $key = hash('sha256', $key); 

                        $salt = utf8_encode(base64_decode($salt)); 

                        $salt = EncodingASCII($salt); 

            



                        $method = 'aes-256-cbc';



            $msg = openssl_decrypt($msg, $method, $key, OPENSSL_RAW_DATA, $salt);  

  

                        return $msg;

}

The encrypt and decrypt works perfect on c#, but I can't get it to decrypt on php. Haven't attempted to make the encrypt in php yet. My c# application calls on the php script with a encrypted data and needs to be decrypted on the php side then encrypted data sent back to the c# application.

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My Answer:
Sure, I can help with that. Please provide me with the specific C code that you need help converting.