Develop Reference

Need help converting c# encryption/Decryption to php

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.

How implement Php's openssl_encrypt method in c#?

as in the title, I need to implement in my C# code the equivalent of php's openssl_encrypt method, because I need to call a service on a php page, but we work with c#.
The php code is this:
$textToEncrypt = "test";
$algo = "AES256";
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($algo));
$key = "1234567890987654"; //Not this key, but just same length
$parametri_enc = openssl_encrypt($textToEncrypt , $algo, $key, 0, $iv);
$iv = bin2hex($iv);
I tried many thing, actually my code is:
string textToEncrypt = "test";
string secretCode = "1234567890987654"
// Create sha256 hash
SHA256 mySHA256 = SHA256Managed.Create();
byte[] key = mySHA256.ComputeHash(Encoding.ASCII.GetBytes(secretCode));
// Create secret IV
byte[] iv = new byte[16];
RandomNumberGenerator generator = RandomNumberGenerator.Create();
generator.GetBytes(iv);
string encryptedText = EncryptString(textToEncrypt, key, iv);
// And I try to port also the bin2hex method
var sb = new StringBuilder();
foreach (byte b in iv)
{
sb.AppendFormat("{0:x2}", b);
}
var tokenBytesHex = sb.ToString();
And the method EncryptString is
public static string EncryptString(string plainText, byte[] key, byte[] iv)
{
//Instantiate a new Aes object to perform string symmetric encryption
Aes encryptor = Aes.Create();
encryptor.Mode = CipherMode.CBC;
// Set key and IV
byte[] aesKey = new byte[32];
Array.Copy(key, 0, aesKey, 0, 32);
encryptor.Key = aesKey;
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 aesEncryptor = encryptor.CreateEncryptor();
// Instantiate a new CryptoStream object to process the data and write it to the
// memory stream
CryptoStream cryptoStream = new CryptoStream(memoryStream, aesEncryptor, CryptoStreamMode.Write);
// Convert the plainText string into a byte array
byte[] plainBytes = Encoding.ASCII.GetBytes(plainText);
// Encrypt the input plaintext string
cryptoStream.Write(plainBytes, 0, plainBytes.Length);
// Complete the encryption process
cryptoStream.FlushFinalBlock();
// Convert the encrypted data from a MemoryStream to a byte array
byte[] cipherBytes = memoryStream.ToArray();
// Close both the MemoryStream and the CryptoStream
memoryStream.Close();
cryptoStream.Close();
// Convert the encrypted byte array to a base64 encoded string
string cipherText = Convert.ToBase64String(cipherBytes, 0, cipherBytes.Length);
// Return the encrypted data as a string
return cipherText;
}
I tried many variation about this porting (that I've found on internet), but without result. If I use a correct encrypted string from my code, I can call the service, so it is working. I need only to encrypt correctly that string, but until now, I've failed

Ok i solved my own problem. I'll share it so if anyone has the same problem, this could work. Basically I saw a decryption c# code here so I update my code in this way
First, I pass my secretCode in string format instead of byte[]
So i changed my method signature in this way:
public static string EncryptString(string plainText, string secretcode, byte[] iv)
and inside I changed the way I manipulate the secretCode (passphrase in php equivalent method)
// Set key and IV
var aesKey = Encoding.ASCII.GetBytes(secretcode);
//pad key out to 32 bytes (256bits) if its too short
if (aesKey.Length < 32)
{
var paddedkey = new byte[32];
Buffer.BlockCopy(aesKey, 0, paddedkey, 0, aesKey.Length);
aesKey = paddedkey;
}
So it worked! No other change, just this two small change from my previous post
Updated method
public static string EncryptString(string plainText, string secretcode, byte[] iv)
{
// Instantiate a new Aes object to perform string symmetric encryption
Aes encryptor = Aes.Create();
encryptor.Mode = CipherMode.CBC;
// Set key and IV
var aesKey = Encoding.ASCII.GetBytes(secretcode);
//pad key out to 32 bytes (256bits) if its too short
if (aesKey.Length < 32)
{
var paddedkey = new byte[32];
Buffer.BlockCopy(aesKey, 0, paddedkey, 0, aesKey.Length);
aesKey = paddedkey;
}
encryptor.Key = aesKey;
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 aesEncryptor = encryptor.CreateEncryptor();
// Instantiate a new CryptoStream object to process the data and write it to the
// memory stream
CryptoStream cryptoStream = new CryptoStream(memoryStream, aesEncryptor, CryptoStreamMode.Write);
// Convert the plainText string into a byte array
byte[] plainBytes = Encoding.ASCII.GetBytes(plainText);
// Encrypt the input plaintext string
cryptoStream.Write(plainBytes, 0, plainBytes.Length);
// Complete the encryption process
cryptoStream.FlushFinalBlock();
// Convert the encrypted data from a MemoryStream to a byte array
byte[] cipherBytes = memoryStream.ToArray();
// Close both the MemoryStream and the CryptoStream
memoryStream.Close();
cryptoStream.Close();
// Convert the encrypted byte array to a base64 encoded string
string cipherText = Convert.ToBase64String(cipherBytes, 0, cipherBytes.Length);
// Return the encrypted data as a string
return cipherText;
}

Junk bytes before payload in C# UTF8 to AES to Base64 conversion

I have been trying to implement proper IV practice in methods to encrypt and decrypt a UTF-8 string with AES which is then returned as a Base64 string. Using this question as a reference, I have prepended the generated IV to the byte array before the Base64 conversion. I'm having an issue where the decrypt method returns the UTF-8 string with exactly fifty characters of random junk (encryption artifacts?). I don't believe the issue is with the encryption because the decrypt method does consistently return the encrypted string. I think the problem is with one of the other conversion steps but I'm having trouble seeing where this might be coming from. Any help would be wildly appreciated.
Encrypt method
public static string EncryptString(string input, string key)
{
using (var aes = new AesCryptoServiceProvider())
{
aes.Key = System.Convert.FromBase64String(key);
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
byte[] rawData = Encoding.UTF8.GetBytes(input);
// IV is the 16 byte AES Initialization Vector
aes.GenerateIV();
using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
{
using (var ms = new MemoryStream())
{
ms.Write(aes.IV, 0, aes.IV.Length); // aes.IV.Length should be 16
using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
{
cs.Write(rawData, 0, rawData.Length);
cs.FlushFinalBlock();
}
byte[] encryptedData = ms.ToArray();
// this will hold the IV prepended to the encrypted data
byte[] output = new byte[aes.IV.Length + encryptedData.Length];
Array.Copy(aes.IV, output, aes.IV.Length); // save the iv
Array.Copy(encryptedData, 0, output, aes.IV.Length, encryptedData.Length); // save the data
// now encode the whole thing as base 64
return System.Convert.ToBase64String(output);
}
}
}
}
Decrypt method
public static string DecryptString(string input, string key)
{
using (var aes = new AesCryptoServiceProvider())
{
aes.Key = Convert.FromBase64String(key);
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
byte[] rawData = Convert.FromBase64String(input);
byte[] IV = new byte[16]; // aes.IV.Length should be 16
Array.Copy(rawData, IV, IV.Length);
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, aes.CreateDecryptor(aes.Key, IV), CryptoStreamMode.Write))
{
using (var binaryWriter = new BinaryWriter(cs))
{
binaryWriter.Write(rawData,IV.Length ,rawData.Length - IV.Length);
}
}
return Encoding.UTF8.GetString(ms.ToArray());
}
}
}
My test
static void Main(string[] args)
{
string payload = "My super secret string";
string key = "tR4mPn7mBQ8G6HWusyFnGk/gqdd/enWiUTr7YbhNrJg=";
Console.WriteLine(payload);
Console.WriteLine(key);
Console.WriteLine("");
string encrypted = EncryptString(payload, key);
Console.WriteLine(encrypted);
Console.WriteLine("");
string decrypted = DecryptString(encrypted, key);
Console.WriteLine(decrypted);
Console.WriteLine(decrypted.Length.ToString() + " " + encrypted.Length.ToString());
Console.ReadKey();
}
Edit to add - this is an example of the output:
�XQ��=F�]�D�?�My super secret string

You are writing the IV to the output twice in EncryptString. First you have:
ms.Write(aes.IV, 0, aes.IV.Length); // aes.IV.Length should be 16
which is the start of encryptedData. You then copy the IV and encryptedData (which already includes the IV) into a new byte array:
// this will hold the IV prepended to the encrypted data
byte[] output = new byte[aes.IV.Length + encryptedData.Length];
Array.Copy(aes.IV, output, aes.IV.Length); // save the iv
Array.Copy(encryptedData, 0, output, aes.IV.Length, encryptedData.Length); // save the data
This doubling of the IV is what is causing the extra bytes.
You don’t need to do the second copying. Just convert encryptedData to base 64 directly and return that:
return System.Convert.ToBase64String(encryptedData);

Rijndael Managed Issue

I have a problem with AES Rijndael Managed encryption in C#
I have a list of around 110,000 image filenames that I want to encrypt individually. I have written an algorithm that encrypts them all together and then a method that decrypts a single image.
The encryption method is as follows:
var saltBytes = Encoding.UTF8.GetBytes(salt);
// The key size for encrypting the images
int KEY_SIZE = 256;
// The initialization vector for encrypting the images
byte[] _initialisationVectorBytes = Encoding.ASCII.GetBytes("EAzjVfNrCzOoE7AI");
//Derives the key from the phrase and the salt
using(var password = new Rfc2898DeriveBytes(password, saltBytes))
{
//use the AES Rijndael algorithm
using(var symmetricKey = new RijndaelManaged())
{
//set the mode
symmetricKey.Mode = CipherMode.CBC;
//create an encryption object
using(var encryptor = symmetricKey.CreateEncryptor(password.GetBytes(KEY_SIZE / 8), _initialisationVectorBytes))
{
//loop through the images
Parallel.ForEach(_sourceImages, image =>
{
//set the plain text bytes and the salt bytes
var plainTextBytes = Encoding.UTF8.GetBytes(image.ImageID.ToString());
var cipherText = string.Empty;
if(_encryptImageFilenames)
{
//create a memory stream
using(var cryptoMemoryStream = new MemoryStream())
{
//create a cryptographic stream
using(var cryptoStream = new CryptoStream(cryptoMemoryStream, encryptor, CryptoStreamMode.Write))
{
//encrypt the image id
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
cipherText = Convert.ToBase64String(cryptoMemoryStream.ToArray());
}
}
}
else
cipherText = image.ImageID.ToString();
}
}
}
}
This works as far as I can tell really well. However when I run the following decryption method, The vast majority of images decrypt correctly however, some images decrypt incorrectly with weird characters, and some give a "Padding is invalid and cannot be removed" error.
// The size of the key
const int KeySize = 256;
// Use the Rijndael Managed algorithm
RijndaelManaged SymmetricKey = new RijndaelManaged();
// The initialisation vector
byte[] initialisationVectorBytes = Encoding.ASCII.GetBytes("EAzjVfNrCzOoE7AI");
try
{
//get the cipher text bytes and the salt bytes
var cipherTextBytes = Convert.FromBase64String(cipherText);
//Derives the key from the phrase and the salt
using(var password = new Rfc2898DeriveBytes(passPhrase, Encoding.UTF8.GetBytes(salt)))
{
//set the mode
SymmetricKey.Mode = CipherMode.CBC;
//create an decryption object
using(var decryptor = SymmetricKey.CreateDecryptor(password.GetBytes(KeySize / 8), initialisationVectorBytes))
{
//create a memory stream
using(var memoryStream = new MemoryStream(cipherTextBytes))
{
//create a crypto stream
using(var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
//decrypt the string
var plainTextBytes = new byte[cipherTextBytes.Length];
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
catch(Exception ex)
{
return string.Empty;
}
So with 110000 images I get a succesful decrypt for all but around 20-30 images, with the failures being one of the two errors earlier.
I cannot for the life of me see why as surely if there was an error in the encrypt method it would affect all images that have been encrypted?
some examples:
Plaintext = 128784
Ciphertext = J2W/5Y1/nvnrpvaWIZhl6g==
Decrypted = 128784
Plaintext = 122875
Ciphertext = N+heUx57427Lk8/Ew10rsA==
Decrypted = �\u0001\u0017275
Plaintext = 121693
Ciphertext = Zf70jcYCbHQqhd23NqD6yA==
Decrypted = 121693
Plaintext = 133456
Ciphertext = wzBgoDaTnGBEyQokI+l6Uw==
Decrypted = "Padding is invalid and cannot be removed"
The password and salt used in these examples are:
Password = "!XbLg`p/0.9nyF?;jGf#nA;e19'TtVk?Ik.l*2=zy.9MYH:7Jmj[|*0N!"
Salt = "alkfdslkaj:H6D£rWe!N,K;?sdoidnalks34334234&(*£';"

Raw HMAC-SHA1 in C# -- hmac_hash() PHP equivalent

I am attempting to integrate Desk.com's Multipass SSO into my website, and am having trouble generating the correct HMAC-SHA1 signature (so say the error logs). Here are the directions from Desk.com's website:
Build a SHA1 HMAC using your multipass API key and your finished multipass token.
Base64 encode the resulting HMAC.
According to the logs, my multipass token appears to be correct. First, the code in PHP that works perfectly:
// Build an HMAC-SHA1 signature using the multipass string and your API key
$signature = hash_hmac("sha1", $multipass, $api_key, true);
// Base64 encode the signature
$signature = base64_encode($signature);
^ note that hash_hmac's 'true' value is outputting information in raw binary - I'm not sure if this is the case in my C# code
Next, my C# code that is not working correctly:
protected string getSignature(string multipass)
{
string api_key = "my_key_goes_here";
HMACSHA1 hmac = new HMACSHA1(Encoding.ASCII.GetBytes(api_key));
hmac.Initialize();
byte[] buffer = Encoding.ASCII.GetBytes(multipass);
string signature = BitConverter.ToString(hmac.ComputeHash(buffer)).Replace("-", "").ToLower();
return Convert.ToBase64String(Encoding.ASCII.GetBytes(signature));
}
This is the result of (literally) hours of searching and trying multiple different ways. I would be very grateful if I could get this figured out.
If you need a reference, check out this page by Desk.com: http://dev.desk.com/docs/portal/multipass. It has code examples and outlines the instructions for completing the code.
Edit: here is my multipass generation code.
protected string getMultipass(UserData user_data)
{
// Encode the data into a JSON object
JavaScriptSerializer s = new JavaScriptSerializer();
string json_data = s.Serialize(user_data);
// Acquire the Web.config appSettings
string site_key = "my_site_here";
string api_key = "my_key_here";
string iv = "OpenSSL for Ruby";
// Using byte arrays now instead of strings
byte[] encrypted = null;
byte[] bIV = Encoding.ASCII.GetBytes(iv);
byte[] data = Encoding.ASCII.GetBytes(json_data);
// XOR the first block (16 bytes)
// once before the full XOR
// so it gets double XORed
for (var i = 0; i < 16; i++)
data[i] = (byte)(data[i] ^ bIV[i]);
// Pad using block size of 16 bytes
int pad = 16 - (data.Length % 16);
Array.Resize(ref data, data.Length + pad);
for (var i = 0; i < pad; i++)
data[data.Length - pad + i] = (byte)pad;
// Use the AesManaged object to do the encryption
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.IV = bIV;
aesAlg.KeySize = 128;
// Create the 16-byte salted hash
SHA1 sha1 = SHA1.Create();
byte[] saltedHash = sha1.ComputeHash(Encoding.UTF8.GetBytes(api_key + site_key), 0, (api_key + site_key).Length);
Array.Resize(ref saltedHash, 16);
aesAlg.Key = saltedHash;
// Encrypt using the AES managed object
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
csEncrypt.Write(data, 0, data.Length);
csEncrypt.FlushFinalBlock();
}
encrypted = msEncrypt.ToArray();
}
}
// Return the Base64-encoded encrypted data
return Convert.ToBase64String(encrypted, Base64FormattingOptions.None)
.TrimEnd("=".ToCharArray()) // Remove trailing "=" characters
.Replace("+", "-") // Change "+" to "-"
.Replace("/", "_"); // Change "/" to "_"
}

You can see the following code that works:
static string create(string userDetails) {
string accountKey = "YOUR_ACCOUNT_KEY";
string apiKey = "YOUR_API_KEY";
string initVector = "OpenSSL for Ruby"; // DO NOT CHANGE
byte[] initVectorBytes = Encoding.UTF8.GetBytes(initVector);
byte[] keyBytesLong;
using( SHA1CryptoServiceProvider sha = new SHA1CryptoServiceProvider() ) {
keyBytesLong = sha.ComputeHash( Encoding.UTF8.GetBytes( apiKey + accountKey ) );
}
byte[] keyBytes = new byte[16];
Array.Copy(keyBytesLong, keyBytes, 16);
byte[] textBytes = Encoding.UTF8.GetBytes(userDetails);
for (int i = 0; i < 16; i++) {
textBytes[i] ^= initVectorBytes[i];
}
// Encrypt the string to an array of bytes
byte[] encrypted = encryptStringToBytes_AES(textBytes, keyBytes, initVectorBytes);
string encoded = Convert.ToBase64String(encrypted);
return HttpUtility.UrlEncode(encoded);
}
static byte[] encryptStringToBytes_AES(byte[] textBytes, byte[] Key, byte[] IV) {
// Declare the stream used to encrypt to an in memory
// array of bytes and the RijndaelManaged object
// used to encrypt the data.
using( MemoryStream msEncrypt = new MemoryStream() )
using( RijndaelManaged aesAlg = new RijndaelManaged() )
{
// Provide the RijndaelManaged object with the specified key and IV.
aesAlg.Mode = CipherMode.CBC;
aesAlg.Padding = PaddingMode.PKCS7;
aesAlg.KeySize = 128;
aesAlg.BlockSize = 128;
aesAlg.Key = Key;
aesAlg.IV = IV;
// Create an encrytor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor();
// Create the streams used for encryption.
using( CryptoStream csEncrypt = new CryptoStream( msEncrypt, encryptor, CryptoStreamMode.Write ) ) {
csEncrypt.Write( textBytes, 0, textBytes.Length );
csEncrypt.FlushFinalBlock();
}
byte[] encrypted = msEncrypt.ToArray();
// Return the encrypted bytes from the memory stream.
return encrypted;
}
}
I hope it works for you.