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C# AES CFB compatibility with 3rd party C implementation

I have a 3rd party AES library for C (from Lantronix). I wrapped their API from within C#'s managed code as shown below, and it works:
[DllImport("cbx_enc.dll", CharSet = CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
static extern unsafe void VC_blockEncrypt(char* iv, char* key, int length, char* text, int RDkeyLen);
/// <summary>
/// Managed Encrypt Wrapper
/// </summary>
/// <param name="buffer">provides the plain text and receives the same length cipher text</param>
static readonly string key = "abcdef0123456789";
static readonly string iv = "0123456789ABCDEF";
public static void Encrypt(ref byte[] buffer)
{
var keyPtr = Marshal.StringToHGlobalAnsi(key);
var ivPtr = Marshal.StringToHGlobalAnsi(iv);
byte[] temp = new byte[16];
Marshal.Copy(ivPtr, temp, 0, 16);
int index = 0;
for (int i = 0; i < buffer.Length; i++)
{
if (index == 0)
{
Marshal.Copy(temp, 0, ivPtr, 16);
unsafe
{
VC_blockEncrypt((char*) ivPtr, (char*) keyPtr, 0, (char*) ivPtr, 128);
}
Marshal.Copy(ivPtr, temp, 0, 16);
index = 16;
}
temp[16 - index] ^= buffer[i];
buffer[i] = temp[16 - index];
index--;
}
Marshal.FreeHGlobal(ivPtr);
Marshal.FreeHGlobal(keyPtr);
}
Now, when I wrote my own, using System.Security.Cryptography to completely avoid using their unmanaged DLL, my final ciphertext seems to differ from them! I am using the same mode, same key, same iv and same plain text, yet the algorithms are not compatible. Shown below is the property settings for the RijndaelManaged object and the code; am I missing something that causes this incompatibility?
/// <summary>
/// Managed Encrypt
/// </summary>
/// <param name="buffer">provides the plain text and receives the same length cipher text</param>
static readonly string key = "abcdef0123456789";
static readonly string iv = "0123456789ABCDEF";
public static void Encrypt(ref byte[] buffer)
{
using (RijndaelManaged cipher = new RijndaelManaged())
{
cipher.Mode = CipherMode.CFB;
cipher.Key = Encoding.ASCII.GetBytes(key);
cipher.IV = Encoding.ASCII.GetBytes(iv);
cipher.Padding = PaddingMode.None;
cipher.FeedbackSize = 128;
ICryptoTransform encryptor = cipher.CreateEncryptor(cipher.Key, cipher.IV);
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (BinaryWriter swEncrypt = new BinaryWriter(csEncrypt))
{
swEncrypt.Write(buffer);
}
buffer = msEncrypt.ToArray();
}
}
}
}
Alternatively, the algorithm that I elucidated from Lantronix architecture looks very straightforward - the API does the encryption, and XORing the output with the plain text is done in the calling-method. Whereas, with .NET library, I don't have such access to the intermediate encrypted output (or is there one?), so that I could XOR the way Lantronix does manually after the encryption...
The end goal is to stop using the unmanaged code, yet should be able to generate the same ciphertext using fully managed .NET code.
Thanks for your help in advance.
p.s. I can provide the 3rd party C library cbx_enc.dll, if you need.
Edit: #Topaco, here are some sample data as requested. Haven’t heard from the vendor as with distributing their DLL; working on it…
Common inputs to CFB:
byte[] buffer = Encoding.ASCII.GetBytes("AAAAAAAAAAAAAABBBBBBBBBBBBBBBBBD"); //plain text
string key = "abcdef0123456789";
string iv = "0123456789ABCDEF";
I/O from the wrapper to the unmanaged DLL:
PlainText Hex: 4141414141414141414141414141424242424242424242424242424242424244
CipherText Hex: C9094F820428E07AE035B6749E18546C62F9D5FD4A78480215DA3625D376A271
I/O from the managed code with FeedbackSize = 128; //CFB128:
PlainText Hex: 4141414141414141414141414141424242424242424242424242424242424244
CipherText Hex: 6A1A5088ACDA505B47192093DD06CD987868BFD85278A4D7D3120CC85FCD3D83
I/O from the managed code with FeedbackSize = 8 //CFB8:
PlainText Hex: 4141414141414141414141414141424242424242424242424242424242424244
CipherText Hex: 6ACA3B1159D38568504248CDFF159C87BB2D3850EDAEAD89493BD91087ED7507
I also did the additional test using ECB to see whether their API behaves like ECB (hence comes the need for external XORing). So, I passed the IV to my ECB code as plain text as shown below, and compared it with their output right before the first XOR – they both don’t match either!
Passed IV as the PlainText to ECB : 30313233343536373839414243444546
CipherText Hex: 2B5B11C9ED9B111A065861D29C478FDA
CipherText Hex from the unmanaged DLL, before the first XOR: 88480EC34569A13BA174F735DF59162E
And finally, here is my ECB implementation for the above test:
static readonly string key = "abcdef0123456789";
static readonly string iv = "0123456789ABCDEF";
public static void Encrypt(ref byte[] buffer)
{
buffer = Encoding.ASCII.GetBytes(iv);
Console.WriteLine($"PlainText: {HexHelper.ToHexString(buffer)}");
var aes = new AesManaged
{
KeySize = 128,
Key = Encoding.ASCII.GetBytes(key),
BlockSize = 128,
Mode = CipherMode.ECB,
Padding = PaddingMode.None,
IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);
buffer = encryptor.TransformFinalBlock(buffer, 0, buffer.Length);
Console.WriteLine($"CipherText: {HexHelper.ToHexString(buffer)}");
}
Thanks.

Like to express my thanks all for the help, especially to #Topaco many thanks – your insight in encoding the plain text in HEX as according to the docs helped!
Here is the revised wrapper code; as you can see its cipher now matches the managed code’s cipher! Perfect!!
static readonly string key = "61626364656630313233343536373839"; //"abcdef0123456789";
static readonly string iv = "0123456789ABCDEF";
public static void Encrypt(ref byte[] buffer)
{
Console.WriteLine($"PlainText: {HexHelper.ToHexString(buffer)}");
var keyPtr = Marshal.StringToHGlobalAnsi(key);
var ivPtr = Marshal.StringToHGlobalAnsi(iv);
byte[] temp = new byte[16];
Marshal.Copy(ivPtr, temp, 0, 16);
int index = 0;
for (int i = 0; i < buffer.Length; i++)
{
if (index == 0)
{
Marshal.Copy(temp, 0, ivPtr, 16);
unsafe
{
VC_blockEncrypt((char*) ivPtr, (char*) keyPtr, 0, (char*) ivPtr, 128);
}
Marshal.Copy(ivPtr, temp, 0, 16);
index = 16;
Console.WriteLine($"CipherText BeforeXOR: {HexHelper.ToHexString(temp)}");
}
temp[16 - index] ^= buffer[i];
buffer[i] = temp[16 - index];
index--;
}
Marshal.FreeHGlobal(ivPtr);
Marshal.FreeHGlobal(keyPtr);
Console.WriteLine($"CipherText: {HexHelper.ToHexString(buffer)}");
}
I/O from the revised wrapper code:
PlainText: 4141414141414141414141414141424242424242424242424242424242424244
CipherText: 6A1A5088ACDA505B47192093DD06CD987868BFD85278A4D7D3120CC85FCD3D83
I/O from the managed code:
PlainText: 4141414141414141414141414141424242424242424242424242424242424244
CipherText: 6A1A5088ACDA505B47192093DD06CD987868BFD85278A4D7D3120CC85FCD3D83
Cheers!!

Specified padding mode is not valid for this algorithm when using AES & PKCS#7 padding in .Net core 2.0

I spent a whole day investigating this and search all related questions on Stack Overflow for this question so please don't mention about possible duplicates.
The code below gives me a System.Security.Cryptography.CryptographicException: 'Specified padding mode is not valid for this algorithm.'
While using the very same parameters on this website : http://aes.online-domain-tools.com it decrypts perfectly into "Hello world" then filled with five 'x05' bytes for padding (PKCS#7 padding).
However the code below will always yield an exception when calling the TransformFinalBlock()
Context:
Console application running on Win8.1 with .NET Core 2.0 / Algorithm is AES / CBC / padding PKCS#7
I also tried the proposed solution here: Specified padding mode is not valid for this algorithm - c# - System.Security.Cryptography but no success (I also don't understand why if IV is already set in the SymmetricAlgorithm instance, it should be used later on when deciphering?
static void Main(string[] args)
{
string encryptedStr = "e469acd421dd71ade4937736c06fdc9d";
string passphraseStr = "1e089e3c5323ad80a90767bdd5907297b4138163f027097fd3bdbeab528d2d68";
string ivStr = "07dfd3f0b90e25e83fd05ba338d0be68";
// Convert hex strings to their ASCII representation
ivStr = HexStringToString(ivStr);
passphraseStr = HexStringToString(passphraseStr);
encryptedStr = HexStringToString(encryptedStr);
// Convert our ASCII strings to byte arrays
byte[] encryptedBytes = Encoding.ASCII.GetBytes(encryptedStr);
byte[] key = Encoding.ASCII.GetBytes(passphraseStr);
byte[] iv = Encoding.ASCII.GetBytes(ivStr);
// Configure our AES decryptor
SymmetricAlgorithm algorithm = Aes.Create();
algorithm.Mode = CipherMode.CBC;
algorithm.Padding = PaddingMode.PKCS7;
algorithm.KeySize = 256;
//algorithm.BlockSize = 128;
algorithm.Key = key;
algorithm.IV = iv;
Console.WriteLine("IV length " + iv.Length); // 16
Console.WriteLine("Key length " + key.Length); // 32
ICryptoTransform transform = algorithm.CreateDecryptor(algorithm.Key, algorithm.IV);
// Perform decryption
byte[] outputBuffer = transform.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
// Convert it back to a string
string result = Encoding.ASCII.GetString(outputBuffer);
Console.WriteLine(result);
Console.ReadLine();
}
public static string HexStringToString(string hexString)
{
var sb = new StringBuilder();
for (var i = 0; i < hexString.Length; i += 2)
{
var hexChar = hexString.Substring(i, 2);
sb.Append((char)Convert.ToByte(hexChar, 16));
}
return sb.ToString();
}

The problem is in the way how you convert hex string to byte array. Try to debug your code and check the value of array encryptedBytes. You'll see the following array:
{ 0x3f, 0x69, 0x3f, 0x3f, 0x21, 0x3f, 0x71, 0x3f, 0x3f, 0x3f, 0x77, 0x36, 0x3f, 0x6f, 0x3f, 0x3f }
which is far from input e469acd421dd71ade4937736c06fdc9d.
You shouldn't use System.String object as just a holder of binary char codes because .Net strings are UTF16-encoded.
Now when root cause is clear, the fix is pretty straighforward. Change your HexStringToString method so that it converts hex string to bytes array directly:
public static byte[] HexStringToByteArray(string hexString)
{
if (hexString.Length % 2 != 0)
{
throw new InvalidOperationException($"Inalid hex string '{hexString}'");
}
byte[] bytes = new byte[hexString.Length / 2];
for (var i = 0; i < hexString.Length; i += 2)
{
var hexChar = hexString.Substring(i, 2);
bytes[i / 2] = Convert.ToByte(hexChar, 16);
}
return bytes;
}
Then adjust the code in Main():
byte[] encryptedBytes = HexStringToByteArray(encryptedStr);
byte[] key = HexStringToByteArray(passphraseStr);
byte[] iv = HexStringToByteArray(ivStr);
This will give you desired Hello world in result variable.

Encryption in ASP.NET that can be decrypted in MySQL with AES_DECRYPT()

I would like to be able to perform application-level encryption in ASP.NET, producing an array of bytes that would then be saved to a MySQL blob column. I would then like it to be an option that, if you have the encryption key, you would be able to decrypt it using MySQL's AES_DECRYPT() function. This seems like it should be possible, since AES_DECRYPT is an implementation of AES/Rijndael.
The MySQL AES_ENCRYPT/DECRYPT functions simply take a key and the string to encrypt/decrypt as parameters. The examples i've seen for encryption in ASP.NET/C#, however, involve also specifying values for Key and IV (initialization vector). How do these affect the final, encrypted byte array, and how can they be taken into account when decrypting with AES_DECRYPT)_?

You can do that by setting RijndaelManaged to use ECB mode.
However, ECB mode is not secure and should be avoided.
In general, a database is a very bad place to perform encryption.
If you are able to encrypt your data in the database, that implies that you have both the ciphertext and the key in the same place; this defeats the purpose of encryption.
You should keep the key as far away from ciphertext storage as possible; using any sort of SQL encryption function is usually indicative of a fundamental design flaw in your encryption strategy which can have disastrous consequences.

Encryption
In Mysql use HEX(AES_ENCRYPT('unencryptedString', 'Password'))
Example
UPDATE `secrets` SET `value`=HEX(AES_ENCRYPT('unencryptedString', 'Password')) WHERE `Id` = 2;
you will see in the database there is a value similar to this D4B5E4CAD92FFB73FCAEB5ED3B31E9EDD8FA7440E9E3F582FE5A9237DB8EE013
Now the equivalent code in C# is (Original Source:link)
public static String AES_encrypt(String Input, string key)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = 128;
aes.BlockSize = 128;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key);
aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null;
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
byte[] xXml = Encoding.UTF8.GetBytes(Input);
cs.Write(xXml, 0, xXml.Length);
cs.FlushFinalBlock();
}
xBuff = ms.ToArray();
}
return xBuff.ToHexString();
}
Helper methods and extensions that used
Refernce Link
private static byte[] mkey(string skey)
{
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = new byte[16] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
for (int i = 0; i < key.Length; i++)
{
k[i % 16] = (byte)(k[i % 16] ^ key[i]);
}
return k;
}
Reference Link
public static class ByteArrayExtensions
{
public static string ToHexString(this byte[] ba)
{
return BitConverter.ToString(ba).Replace("-", "");
}
}
Decryption
in Mysql use CAST(AES_DECRYPT(UNHEX(c.value), 'Password') as char)
Example
SELECT c.*,CAST(AES_DECRYPT(UNHEX(c.`value`), 'Password') as char) FROM `secrets` as c where `Id` = 2;
Equivalent code in C# is
public static String AES_decrypt(String Input, string key)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = 128;
aes.BlockSize = 128;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key);
aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
var decrypt = aes.CreateDecryptor();
byte[] encryptedStr = Input.FromHex2ByteArray();
string Plain_Text;
using (var ms = new MemoryStream(encryptedStr))
{
using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Read))
{
using (StreamReader reader = new StreamReader(cs))
{
Plain_Text = reader.ReadToEnd();
}
}
}
return Plain_Text;
}
Helper methods and extensions that used
Reference Link
private static byte[] mkey(string skey)
{
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = new byte[16] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
for (int i = 0; i < key.Length; i++)
{
k[i % 16] = (byte)(k[i % 16] ^ key[i]);
}
return k;
}
Reference Link
public static byte[] FromHex2ByteArray(this string hex)
{
if (hex.Length % 2 == 1)
throw new Exception("The binary key cannot have an odd number of digits");
byte[] arr = new byte[hex.Length >> 1];
for (int i = 0; i < hex.Length >> 1; ++i)
{
arr[i] = (byte)((GetHexVal(hex[i << 1]) << 4) + (GetHexVal(hex[(i << 1) + 1])));
}
return arr;
}
private static int GetHexVal(char hex)
{
int val = (int)hex;
//For uppercase A-F letters:
//return val - (val < 58 ? 48 : 55);
//For lowercase a-f letters:
//return val - (val < 58 ? 48 : 87);
//Or the two combined, but a bit slower:
return val - (val < 58 ? 48 : (val < 97 ? 55 : 87));
}

Two methods for Des Cryptography returns two different result?

I want to claculate the MAC(Message Authentication Code) CBC chiper(Ansi x9.9), i found a sample which calculates the MAC based on a cycle, in each round the encrypted reuslt must be XOR with next round plain Text block and the result should be encrepted to being used to next step and this cycle repeats for 4 times till the last encrypted value must be return as MAC.
Cryptographic Key = 0123456789abcdef
The text is the ASCII code for "7654321 Now is the time for ".
Text = 37363534333231204e6f77206873207468652074696d6520666f7220
TIME --- PLAIN TEXT---------------DES INPUT BLOCK -------- DES OUTPUT BLOCK
1 ---- 3736353433323120 -------- 3736353433323120 -------- 21fb193693a16c28
2 ---- 4e6f772068732074 -------- 6f946e16fad24c5c -------- 6c463f0cb7167a6f
3 ---- 68652074696d6520 -------- 04231f78de7b1f4f -------- 956ee891e889d91e
4 ---- 666f722000000000 -------- f3019ab1e889d91e -------- f1d30f6849312ca4
I tried to implement this sample. at the first step i got the same result as the sample but for the next step my Des encryption function returns the different resutl as the sample's 2th step. i used a hardware device to encrypt each Des input block, it returns the same DES output block as the sample return. either i found another DES implementation sample here it reutrns the correct encrption too. but my app which uses microsft example on msdn returns the incorrect result for steps 2,3 and 4 except step 1. here is my code:
public byte[] EncryptPart(byte[] toEncrypt, byte[] Key, byte[] IV)
{
try
{
MemoryStream mStream = new MemoryStream();
DES DESalg = DES.Create();
DESalg.Mode = CipherMode.CBC;
DESalg.Padding = PaddingMode.None;
CryptoStream cStream = new CryptoStream(mStream,
DESalg.CreateEncryptor(Key, IV),
CryptoStreamMode.Write);
cStream.Write(toEncrypt, 0, toEncrypt.Length);
cStream.FlushFinalBlock();
byte[] ret = mStream.ToArray();
cStream.Close();
mStream.Close();
return ret;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
and here where i have used that function
var IV = new byte[8];//empty byte array
var key = new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef };
var result = new byte[8];
int LoopCount = data.Length / 8;
for (int i = 0; i < LoopCount; i++)
{
byte[] Part= new byte[8];
Array.Copy(data, i * 8, Part, 0, 8);
Part = XorArray(Part, result);
result = EncryptPart(Part, key, IV);
}
int remain=data.Length % 8;
if (remain != 0)
{
byte[] LastPart = new byte[8];//
Array.Copy(data, data.Length - remain, LastPart, 0, remain);
LastPart=XorArray(LastPart, result);
result = EncryptPart(LastPart, key, IV);
}

You should reuse the cypher instead of reinitialising it with the key and IV each time.
The calling code:
var IV = new byte[8];//empty byte array
var key = new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef };
var data = Encoding.ASCII.GetBytes("7654321 Now is the time for ");
DES DESalg = DES.Create();
DESalg.Mode = CipherMode.CBC;
DESalg.Padding = PaddingMode.None;
ICryptoTransform crypt = DESalg.CreateEncryptor(key, IV);
var result = new byte[8];
int LoopCount = data.Length / 8;
for (int i = 0; i < LoopCount; i++)
{
Console.WriteLine("=============Round {0}==============", i + 1);
byte[] part = new byte[8];
Array.Copy(data, i * 8, part, 0, 8);
Console.WriteLine("Plain text : {0}", ByteArrayToString(part));
part = XorArray(part, result);
Console.WriteLine("DES INPUT : {0}", ByteArrayToString(part));
result = EncryptPart(crypt, part);
}
int remain = data.Length % 8;
if (remain != 0)
{
Console.WriteLine("===========Final Round==============");
byte[] LastPart = new byte[8];//
Array.Copy(data, data.Length - remain, LastPart, 0, remain);
Console.WriteLine("Plain text : " + ByteArrayToString(LastPart));
LastPart = XorArray(LastPart, result);
Console.WriteLine("DES INPUT : " + ByteArrayToString(LastPart));
result = EncryptPart(crypt, LastPart);
}
Console.WriteLine("Result: {0}", ByteArrayToString(result));
And the modified Encrypt part method:
public static byte[] EncryptPart(ICryptoTransform crypt, byte[] toEncrypt)
{
try
{
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream,
crypt,
CryptoStreamMode.Write);
cStream.Write(toEncrypt, 0, toEncrypt.Length);
cStream.FlushFinalBlock();
byte[] ret = mStream.ToArray();
cStream.Close();
mStream.Close();
Console.WriteLine("DES OUTPUT : " + ByteArrayToString(ret));
return ret;
}
catch (CryptographicException e)
{
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
return null;
}
}
And the results:
=============Round 1==============
Plain text : 3736353433323120
DES INPUT : 3736353433323120
DES OUTPUT : 21fb193693a16c28
=============Round 2==============
Plain text : 4e6f772069732074
DES INPUT : 6f946e16fad24c5c
DES OUTPUT : 6c463f0cb7167a6f
=============Round 3==============
Plain text : 68652074696d6520
DES INPUT : 04231f78de7b1f4f
DES OUTPUT : 956ee891e889d91e
===========Final Round============
Plain text : 666f722000000000
DES INPUT : f3019ab1e889d91e
DES OUTPUT : f1d30f6849312ca4
Result: f1d30f6849312ca4
These values match the ones you specified, and those in this specification

The root cause of the error is from the hexadecimal string provided by the FIPS 113 document.
Text : "7654321 Now is the time for "
Hex(Wrong) : "37363534333231204e6f77206873207468652074696d6520666f7220"
Hex(Correct): "37363534333231204e6f77206973207468652074696d6520666f7220"

Odd Encryption/Decryption Error (C# - AES)

I found the following AES encryption class from another question here. The class (as is) works great, however, I have been trying to modify the class to my liking which is where I have encountered these errors. Please note that it is a binary file that I am trying to encrypt.
First I will explain the changes I am trying to make.
1) I want to change the parameter of the Encrypt function from a string, to a byte array. I thought this would be very simple task (just do a quick File.ReadAllBytes and pass the byte array to the Encrypt function) but this was not the case.
2) I want the decrypt function to return a byte array. Same issue as above, I can't get this to work properly.
I was hoping that someone would be able to give me a working example of encrypting and decrypting a binary file similar to what I have setup below:
private void button1_Click(object sender, EventArgs e)
{
SimpleAES sa = new SimpleAES();
OpenFileDialog ofd = new OpenFileDialog();
string s = string.Empty;
byte[] b = null;
if (ofd.ShowDialog() == DialogResult.OK)
{
textBox1.Text = ofd.FileName;
b = File.ReadAllBytes(ofd.FileName);
b = sa.Encrypt(ByteToString(b);
}
File.WriteAllBytes(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + #"\TestData123.exe", b);
}
private void button2_Click(object sender, EventArgs e)
{
SimpleAES sa = new SimpleAES();
byte[] b = File.ReadAllBytes(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + #"\TestData123.exe");
string s = sa.Decrypt(b);
File.Delete(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + #"\TestData123.exe");
File.WriteAllBytes(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + #"\TestData.exe", b);
}
public byte[] StringToByte(string s)
{
Byte[] b = new byte[s.Length];
for (int i = 0; i < s.Length; i++)
{
char c = Convert.ToChar(s.Substring(i, 1));
b[i] = Convert.ToByte(c);
}
return b;
}
public string ByteToString(byte[] input)
{
StringBuilder ss = new System.Text.StringBuilder();
for (int i = 0; i < input.Length; i++)
{
// Convert each byte to char
char c = Convert.ToChar(input[i]);
ss.Append(Convert.ToString(c));
}
return ss.ToString();
}
Here is the AES class I am using:
using System;
using System.Data;
using System.Security.Cryptography;
using System.IO;
public class SimpleAES
{
// Change these keys
private byte[] Key = { 123, 217, 19, 11, 24, 26, 85, 45, 114, 184, 27, 162, 37, 112, 222, 209, 241, 24, 175, 144, 173, 53, 196, 29, 24, 26, 17, 218, 131, 236, 53, 209 };
private byte[] Vector = { 146, 64, 191, 111, 23, 3, 113, 119, 231, 121, 221, 112, 79, 32, 114, 156 };
private ICryptoTransform EncryptorTransform, DecryptorTransform;
private System.Text.UTF8Encoding UTFEncoder;
public SimpleAES()
{
//This is our encryption method
RijndaelManaged rm = new RijndaelManaged();
//Create an encryptor and a decryptor using our encryption method, key, and vector.
EncryptorTransform = rm.CreateEncryptor(this.Key, this.Vector);
DecryptorTransform = rm.CreateDecryptor(this.Key, this.Vector);
//Used to translate bytes to text and vice versa
UTFEncoder = new System.Text.UTF8Encoding();
}
/// -------------- Two Utility Methods (not used but may be useful) -----------
/// Generates an encryption key.
static public byte[] GenerateEncryptionKey()
{
//Generate a Key.
RijndaelManaged rm = new RijndaelManaged();
rm.GenerateKey();
return rm.Key;
}
/// Generates a unique encryption vector
static public byte[] GenerateEncryptionVector()
{
//Generate a Vector
RijndaelManaged rm = new RijndaelManaged();
rm.GenerateIV();
return rm.IV;
}
/// ----------- The commonly used methods ------------------------------
/// Encrypt some text and return a string suitable for passing in a URL.
public string EncryptToString(string TextValue)
{
return ByteArrToString(Encrypt(TextValue));
}
/// Encrypt some text and return an encrypted byte array.
public byte[] Encrypt(string TextValue)
{
//Translates our text value into a byte array.
Byte[] bytes = UTFEncoder.GetBytes(TextValue);
//Used to stream the data in and out of the CryptoStream.
MemoryStream memoryStream = new MemoryStream();
/*
* We will have to write the unencrypted bytes to the stream,
* then read the encrypted result back from the stream.
*/
#region Write the decrypted value to the encryption stream
CryptoStream cs = new CryptoStream(memoryStream, EncryptorTransform, CryptoStreamMode.Write);
cs.Write(bytes, 0, bytes.Length);
cs.FlushFinalBlock();
#endregion
#region Read encrypted value back out of the stream
memoryStream.Position = 0;
byte[] encrypted = new byte[memoryStream.Length];
memoryStream.Read(encrypted, 0, encrypted.Length);
#endregion
//Clean up.
cs.Close();
memoryStream.Close();
return encrypted;
}
/// The other side: Decryption methods
public string DecryptString(string EncryptedString)
{
return Decrypt(StrToByteArray(EncryptedString));
}
/// Decryption when working with byte arrays.
public string Decrypt(byte[] EncryptedValue)
{
#region Write the encrypted value to the decryption stream
MemoryStream encryptedStream = new MemoryStream();
CryptoStream decryptStream = new CryptoStream(encryptedStream, DecryptorTransform, CryptoStreamMode.Write);
decryptStream.Write(EncryptedValue, 0, EncryptedValue.Length);
decryptStream.FlushFinalBlock();
#endregion
#region Read the decrypted value from the stream.
encryptedStream.Position = 0;
Byte[] decryptedBytes = new Byte[encryptedStream.Length];
encryptedStream.Read(decryptedBytes, 0, decryptedBytes.Length);
encryptedStream.Close();
#endregion
return UTFEncoder.GetString(decryptedBytes);
}
/// Convert a string to a byte array. NOTE: Normally we'd create a Byte Array from a string using an ASCII encoding (like so).
// System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
// return encoding.GetBytes(str);
// However, this results in character values that cannot be passed in a URL. So, instead, I just
// lay out all of the byte values in a long string of numbers (three per - must pad numbers less than 100).
public byte[] StrToByteArray(string str)
{
if (str.Length == 0)
throw new Exception("Invalid string value in StrToByteArray");
byte val;
byte[] byteArr = new byte[str.Length / 3];
int i = 0;
int j = 0;
do
{
val = byte.Parse(str.Substring(i, 3));
byteArr[j++] = val;
i += 3;
}
while (i < str.Length);
return byteArr;
}
// Same comment as above. Normally the conversion would use an ASCII encoding in the other direction:
// System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
// return enc.GetString(byteArr);
public string ByteArrToString(byte[] byteArr)
{
byte val;
string tempStr = "";
for (int i = 0; i <= byteArr.GetUpperBound(0); i++)
{
val = byteArr[i];
if (val < (byte)10)
tempStr += "00" + val.ToString();
else if (val < (byte)100)
tempStr += "0" + val.ToString();
else
tempStr += val.ToString();
}
return tempStr;
}
}
Thank you very much everyone!

Edited the code you provided to work as per the requirements.
private static byte[] Key = { 123, 217, 19, 11, 24, 26, 85, 45, 114, 184, 27, 162, 37, 112, 222, 209, 241, 24, 175, 144, 173, 53, 196, 29, 24, 26, 17, 218, 131, 236, 53, 209 };
private static byte[] Vector = { 146, 64, 191, 111, 23, 3, 113, 119, 231, 121, 221, 112, 79, 32, 114, 156 };
private static RijndaelManaged _rijndaelManaged;
static void Main(string[] args)
{
var allBytes = File.ReadAllBytes("hello.bin");
_rijndaelManaged = new RijndaelManaged { Key = Key, IV = Vector };
byte[] encBytes = Encrypt(allBytes, Key, Vector);
byte[] decBytes = Decrypt(encBytes, Key, Vector);
using (var mstream = new MemoryStream(decBytes))
using (var breader = new BinaryReader(mstream))
{
Console.WriteLine(breader.ReadString());
}
}
private static byte[] Decrypt(byte[] encBytes, byte[] key, byte[] vector)
{
byte[] decBytes;
using (var mstream = new MemoryStream())
using (var crypto = new CryptoStream(mstream, _rijndaelManaged.CreateDecryptor(key, vector), CryptoStreamMode.Write))
{
crypto.Write(encBytes, 0, encBytes.Length);
crypto.FlushFinalBlock();
mstream.Position = 0;
decBytes = new byte[mstream.Length];
mstream.Read(decBytes, 0, decBytes.Length);
}
return decBytes;
}
private static byte[] Encrypt(byte[] allBytes, byte[] key, byte[] vector)
{
byte[] encBytes;
using (var mstream = new MemoryStream())
using (var crypto = new CryptoStream(mstream, _rijndaelManaged.CreateEncryptor(key, vector), CryptoStreamMode.Write))
{
crypto.Write(allBytes, 0, allBytes.Length);
crypto.FlushFinalBlock();
mstream.Position = 0;
encBytes = new byte[mstream.Length];
mstream.Read(encBytes, 0, encBytes.Length);
}
return encBytes;
}
As Eoin explained, all you had to do was remove the line which converted the bytes back to the string. I posted the entire working code as I was not sure whether the input file being a binary file was causing any issues. It doesnt.

Evan,
I think you might be over complicating things here. And without doing any checking, I think the problem lies with your StringToByte & ByteToString methods. You should really be using one of the System.Text.Encoding classes for string->byte conversion (just like the AES Class does)
But if you only need to encrypt a source byte[] to a destination byte[] you can do the following and forget about strings completely.
Change the SimpleAES Encrypt & Decrypt Signatures as follows
public byte[] Encrypt(Byte[] bytes) //Change To take in a byte[]
{
//Translates our text value into a byte array.
//Byte[] bytes = UTFEncoder.GetBytes(TextValue); <-- REMOVE THIS LINE
... do stuff with `bytes`
}
public byte[] Decrypt(byte[] EncryptedValue) //now returns a byte array instead of a string
{
//return UTFEncoder.GetString(decryptedBytes); <-- JUST RETURN THE BYTE[] INSTEAD
return decryptedBytes;
}
So now you just feed it and input byte [] and receive an encrypted byte [] back.
You can verify this in the debugger using.
SimpleAES sa = new SimpleAES();
byte[] plainBytes = new byte[] { 0x01, 0xFF, 0x53, 0xC2};
byte[] encBytes = sa.Encrypt(plainBytes);
byte[] decBytes = sa.Decrypt(encBytes);
//BREAK HERE
//Compare the values of decBytes & plainBytes