Decrypt AES returned from a PHP script in a C# application

First of all, I know that this question is available here a lot - but they are not the ones I want.

I am trying to encrypt data on a PHP script then decrypt it later on a C# application

My current PHP code:

$plaintext = 'My secret message 1234'; $password = '3sc3RLrpd17'; $method = 'aes-256-cbc'; $key = password_hash($password, PASSWORD_BCRYPT, ['cost' => 12]); // IV must be exact 16 chars (128 bit) $iv = chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0) . chr(0x0); // av3DYGLkwBsErphcyYp+imUW4QKs19hUnFyyYcXwURU= $encrypted = base64_encode(openssl_encrypt($plaintext, $method, $key, OPENSSL_RAW_DATA, $iv)); echo $encrypted; 

After that, I want to decrypt the value of $encrypted on my C# application...

I am currently doing it like that:

public string DecryptString(string cipherText, byte[] key, byte[] iv) { // Instantiate a new Aes object to perform string symmetric encryption Aes encryptor = Aes.Create(); encryptor.Mode = CipherMode.CBC; //encryptor.KeySize = 256; //encryptor.BlockSize = 128; //encryptor.Padding = PaddingMode.Zeros; // Set key and IV encryptor.Key = key.Take(32).ToArray(); encryptor.IV = iv; // Instantiate a new MemoryStream object to contain the encrypted bytes MemoryStream memoryStream = new MemoryStream(); // Instantiate a new encryptor from our Aes object ICryptoTransform aesDecryptor = encryptor.CreateDecryptor(); // Instantiate a new CryptoStream object to process the data and write it to the // memory stream CryptoStream cryptoStream = new CryptoStream(memoryStream, aesDecryptor, CryptoStreamMode.Write); // Will contain decrypted plaintext string plainText = String.Empty; try { // Convert the ciphertext string into a byte array byte[] cipherBytes = Convert.FromBase64String(cipherText); // Decrypt the input ciphertext string cryptoStream.Write(cipherBytes, 0, cipherBytes.Length); // Complete the decryption process cryptoStream.FlushFinalBlock(); // Convert the decrypted data from a MemoryStream to a byte array byte[] plainBytes = memoryStream.ToArray(); // Convert the decrypted byte array to string plainText = Encoding.ASCII.GetString(plainBytes, 0, plainBytes.Length); } finally { // Close both the MemoryStream and the CryptoStream memoryStream.Close(); cryptoStream.Close(); } // Return the decrypted data as a string return plainText; } string password = "3sc3RLrpd17"; // hash the password with BCrypt string hashedPassword = BCrypt.Net.BCrypt.HashPassword(password, 12); // Convert hashed password to array byte[] key = Encoding.ASCII.GetBytes(hashedPassword); // Create secret IV byte[] iv = new byte[16] { 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 }; string decrypted = this.DecryptString(encrypted, key, iv); 

But at last, the value of decrypted is the not My secret message 1234

The error I get is: Padding is invalid and cannot be removed.

DISCLAIMER: I have the BCrypt package installed.

I think that the problem is in the iv.

I've tried a lot to fix it.

Any help would be appreciated.

Thanks!