C＃到PHP AES解密

Question

Hi i have c# sample of code but i can't turn it to php. İ tried to rewrite code but i can't do it. In my project other server encrypts data with c# and i have to decrypt it using PHP.

I have password and salt value.

Here is C# code includes encrypt and decrypt function.

using System;

using System.Collections.Generic;

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

namespace EncryptionSample
{
    public static class CipherUtility
    {
        public static string Encrypt(string plainText, string password, string salt)
        {
            if (plainText == null || plainText.Length <= 0)
            {
                throw new ArgumentNullException("plainText");
            }

            if (String.IsNullOrEmpty(password))
            {
                throw new ArgumentNullException("password");
            }

            if (String.IsNullOrEmpty(salt))
            {
                throw new ArgumentNullException("salt");
            }

            byte[] encrypted;
            byte[] saltBytes = Encoding.UTF8.GetBytes(salt);

            using (Rfc2898DeriveBytes derivedBytes = new Rfc2898DeriveBytes(password, saltBytes))
            {
                using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
                {
                    aesAlg.Key = derivedBytes.GetBytes(32);
                    aesAlg.IV = derivedBytes.GetBytes(16);

                    ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

                    using (MemoryStream msEncrypt = new MemoryStream())
                    {
                        using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                        {
                            using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                            {
                                swEncrypt.Write(plainText);
                            }

                            encrypted = msEncrypt.ToArray();
                        }
                    }
                }
            }

            return Convert.ToBase64String(encrypted);
        }

        public static string Decrypt(string cipherValue, string password, string salt)
        {
            byte[] cipherText = Convert.FromBase64String(cipherValue);

            if (cipherText == null 
                || cipherText.Length <= 0)
            {
                throw new ArgumentNullException("cipherValue");
            }

            if (String.IsNullOrWhiteSpace(password))
            {
                throw new ArgumentNullException("password");
            }

            if (String.IsNullOrWhiteSpace(password))
            {
                throw new ArgumentNullException("salt");
            }

            string plaintext = null;
            byte[] saltBytes = Encoding.UTF8.GetBytes(salt);

            using (Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(password, saltBytes))
            {
                using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
                {
                    aesAlg.Key = deriveBytes.GetBytes(32);
                    aesAlg.IV = deriveBytes.GetBytes(16);

                    ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

                    using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                    {
                        using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                        {
                            using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                            {
                                plaintext = srDecrypt.ReadToEnd();
                            }
                        }
                    }
                }
            }

            return plaintext;
        }
    }
}

My php code is here but i think i am totally wrong.

function decrypt($encrypted, $password, $salt) {
 // Build a 256-bit $key which is a SHA256 hash of $salt and $password.
 $key = hash('SHA256', $salt . $password, true);
 // Retrieve $iv which is the first 22 characters plus ==, base64_decoded.
 $iv = base64_decode(substr($encrypted, 0, 22) . '==');
// print_r($iv);die();
 // Remove $iv from $encrypted.
 $encrypted = substr($encrypted, 22);
 //print_r($encrypted);die();
 // Decrypt the data.  rtrim won't corrupt the data because the last 32 characters are the md5 hash; thus any \0 character has to be padding.

 $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, base64_decode($encrypted), MCRYPT_MODE_CBC, $iv), "\0\4");

 // Retrieve $hash which is the last 32 characters of $decrypted.
 $hash = substr($decrypted, -32);
 // Remove the last 32 characters from $decrypted.
 $decrypted = substr($decrypted, 0, -32);
 // Integrity check.  If this fails, either the data is corrupted, or the password/salt was incorrect.
 if (md5($decrypted) != $hash) return false;

 return $decrypted;
 }

Answer 1

I'm no crypto expert, but I think you might find phpseclib useful.