Encrypt in VB.NET and Decrypt in PHP
encryption, php, tripledes, vb.net
Solution
Since no one was able to provide a fully functional BI-DIRECTIONAL solution, I have taken the liberty to provide one for the community on this article.
The problem, is that PHP does not conform to the standards by forcing the strings to be padded in order to match. Presently, there is no known way to reliably pass the IV if randomly generated between .NET and PHP (if you do discover how, or this changes, please feel free to revise this).
Following is the COMPLETE solution for encrypting data using Triple DES in a manner that is compatible with .NET and PHP which allows for bi-directional Triple DES encrypted communication. This method is also compatible with Java, Delphi, Objective-C, and many other languages, however such code is not going to be supplied here as that is not a solution to the posted question.
VB.NET Triple DES Class
Imports System
Imports System.Text
Imports System.IO
Imports System.Security.Cryptography
Public Class TripleDES
Private bPassword As Byte()
Private sPassword As String
Public Sub New(Optional ByVal Password As String = "password")
' On Class Begin
Me.Password = Password
End Sub
Public ReadOnly Property PasswordHash As String
Get
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Return UTF8.GetString(bPassword)
End Get
End Property
Public Property Password() As String
Get
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Return sPassword
End Get
Set(value As String)
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Dim HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
bPassword = HashProvider.ComputeHash(UTF8.GetBytes(value))
sPassword = value
End Set
End Property
#Region "Encrypt"
' Encrypt using Password from Property Set (pre-hashed)
Public Function Encrypt(ByVal Message As String) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = bPassword
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
Dim DataToEncrypt() As Byte = UTF8.GetBytes(Message)
Try
Dim Encryptor As ICryptoTransform = TDESAlgorithm.CreateEncryptor
Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length)
Finally
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
Return Convert.ToBase64String(Results)
End Function
' Encrypt using Password as byte array
Private Function Encrypt(ByVal Message As String, ByVal Password() As Byte) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = HashProvider.ComputeHash(UTF8.GetBytes(UTF8.GetString(Password)))
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
Dim DataToEncrypt() As Byte = UTF8.GetBytes(Message)
Try
Dim Encryptor As ICryptoTransform = TDESAlgorithm.CreateEncryptor
Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length)
Finally
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
Return Convert.ToBase64String(Results)
End Function
' Encrypt using Password as string
Public Function Encrypt(ByVal Message As String, ByVal Password As String) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
' Step 1. We hash the Passphrase using MD5
' We use the MD5 hash generator as the result is a 128 bit byte array
' which is a valid length for the Triple DES encoder we use below
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = HashProvider.ComputeHash(UTF8.GetBytes(Password))
' Step 2. Create a new TripleDESCryptoServiceProvider object
' Step 3. Setup the encoder
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
' Step 4. Convert the input string to a byte[]
Dim DataToEncrypt() As Byte = UTF8.GetBytes(Message)
' Step 5. Attempt to encrypt the string
Try
Dim Encryptor As ICryptoTransform = TDESAlgorithm.CreateEncryptor
Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length)
Finally
' Clear the Triple Des and Hashprovider services of any sensitive information
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
' Step 6. Return the encrypted string as a base64 encoded string
Return Convert.ToBase64String(Results)
End Function
#End Region
#Region "Decrypt"
' Decrypt using Password from Property (pre-hashed)
Public Function Decrypt(ByVal Message As String) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = Me.bPassword
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
Dim DataToDecrypt() As Byte = Convert.FromBase64String(Message)
Try
Dim Decryptor As ICryptoTransform = TDESAlgorithm.CreateDecryptor
Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length)
Finally
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
Return UTF8.GetString(Results)
End Function
' Decrypt using Password as Byte array
Public Function Decrypt(ByVal Message As String, ByVal Password() As Byte) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = HashProvider.ComputeHash(UTF8.GetBytes(UTF8.GetString(Password)))
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
Dim DataToDecrypt() As Byte = Convert.FromBase64String(Message)
Try
Dim Decryptor As ICryptoTransform = TDESAlgorithm.CreateDecryptor
Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length)
Finally
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
Return UTF8.GetString(Results)
End Function
' Decrypt using Password as string
Public Function Decrypt(ByVal Message As String, ByVal Password As String) As String
Dim Results() As Byte
Dim UTF8 As System.Text.UTF8Encoding = New System.Text.UTF8Encoding
' Step 1. We hash the pass phrase using MD5
' We use the MD5 hash generator as the result is a 128-bit byte array
' which is a valid length for the Triple DES encoder we use below
Using HashProvider As MD5CryptoServiceProvider = New MD5CryptoServiceProvider()
Dim TDESKey() As Byte = HashProvider.ComputeHash(UTF8.GetBytes(Password))
' Step 2. Create a new TripleDESCryptoServiceProvider object
' Step 3. Setup the decoder
Using TDESAlgorithm As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider() With {.Key = TDESKey, .Mode = CipherMode.ECB, .Padding = PaddingMode.PKCS7}
' Step 4. Convert the input string to a byte[]
Dim DataToDecrypt() As Byte = Convert.FromBase64String(Message)
' Step 5. Attempt to decrypt the string
Try
Dim Decryptor As ICryptoTransform = TDESAlgorithm.CreateDecryptor
Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length)
Finally
' Clear the Triple Des and Hash provider services of any sensitive information
TDESAlgorithm.Clear()
HashProvider.Clear()
End Try
End Using
End Using
' Step 6. Return the decrypted string in UTF8 format
Return UTF8.GetString(Results)
End Function
#End Region
End Class
VB.NET Triple DES Class Usage
Dim tdes As New TripleDES("12345")
Dim vbEncrypted = tdes.Encrypt("Encrypted using VB.NET")
Dim phpEncrypted = "5Ittyr0+jiI7QQmPrvSVnMc9MEWQCjAN"
Debug.Print("PHP Encrypted: " & phpEncrypted)
Debug.Print("VB Encrypted: " & vbEncrypted)
Debug.Print("PHP Encrypted (decrypted result): " & tdes.Decrypt(phpEncrypted))
Debug.Print("VB Encrypted (decrypted result): " & tdes.Decrypt(vbEncrypted))
PHP Triple DES Class
class TripleDES {
private $bPassword;
private $sPassword;
function __construct($Password) {
$this->bPassword = md5(utf8_encode($Password),TRUE);
$this->bPassword .= substr($this->bPassword,0,8);
$this->sPassword - $Password;
}
function Password($Password = "") {
if($Password == "") {
return $this->sPassword;
} else {
$this->bPassword = md5(utf8_encode($Password),TRUE);
$this->bPassword .= substr($this->bPassword,0,8);
$this->sPassword - $Password;
}
}
function PasswordHash() {
return $this->bPassword;
}
function Encrypt($Message, $Password = "") {
if($Password <> "") { $this->Password($Password); }
$size=mcrypt_get_block_size('tripledes','ecb');
$padding=$size-((strlen($Message)) % $size);
$Message .= str_repeat(chr($padding),$padding);
$encrypt = mcrypt_encrypt('tripledes',$this->bPassword,$Message,'ecb');
return base64_encode($encrypt);
}
function Decrypt($message, $Password = "") {
if($Password <> "") { $this->Password($Password); }
return trim(mcrypt_decrypt('tripledes', $this->bPassword, base64_decode($message), 'ecb'), ord(2));
}
}
PHP Triple DES Class Usage
$tdes = new TripleDES("12345");
$phpEncrypted = $tdes->encrypt("Encrypted using PHP");
$vbEncrypted = "5Ittyr0+jiI7QQmPrvSVnP3s2CeoTJmF"; // Encrypted using VB.NET
echo "PHP Encrypted: " . $phpEncrypted . '<br />';
echo "VB Encrypted: " . $vbEncrypted . '<br />';
echo "PHP Encrypted (decrypted result): " . $tdes->Decrypt($phpEncrypted) . '<br />';
echo "VB Encrypted (decrypted result): " . $tdes->Decrypt($vbEncrypted) . '<br />';
I did what I could to make both classes usability level identical as the languages would allow naturally. Since PHP does not allow overloading functions, I had to use the password as an optional parameter, which is a string value. The VB.NET solution has an additional override that allows you to pass the byte value of the password string on encrypt/decrypt functions. The example code provided to show the usage for each, shows the most simplistic form of instantiating the object which both classes allow for setting the password on object creation.
For anyone else out there that was bashing their brains trying to find a WORKING bi-directional solution for Triple DES (and did not want to be forced into the box that everyone seems to be pointing to -- Rijndael), then this solution is for you, and you can stop banging your head against the wall.
Added a C# translation of the VB.NET TripleDES class
C# Class ( Added [2017-01-11] )
using System;
using System.Security.Cryptography;
public class TripleDES {
private byte[] bPassword;
private string sPassword;
public TripleDES( string Password = "password" ) {
// On Class Begin
this.Password = Password;
}
public string PasswordHash {
get {
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
return UTF8.GetString( bPassword );
}
}
public string Password {
get {
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
return sPassword;
}
set {
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
bPassword = HashProvider.ComputeHash( UTF8.GetBytes( value ) );
sPassword = value;
}
}
#region "Encrypt"
// Encrypt using Password from Property Set (pre-hashed)
public string Encrypt( string Message ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = bPassword;
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
byte[] DataToEncrypt = UTF8.GetBytes( Message );
try {
ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
Results = Encryptor.TransformFinalBlock( DataToEncrypt, 0, DataToEncrypt.Length );
} finally {
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
return Convert.ToBase64String( Results );
}
// Encrypt using Password as byte array
private string Encrypt( string Message, byte[] Password ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = HashProvider.ComputeHash( UTF8.GetBytes( UTF8.GetString( Password ) ) );
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
byte[] DataToEncrypt = UTF8.GetBytes( Message );
try {
ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
Results = Encryptor.TransformFinalBlock( DataToEncrypt, 0, DataToEncrypt.Length );
} finally {
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
return Convert.ToBase64String( Results );
}
// Encrypt using Password as string
public string Encrypt( string Message, string Password ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
// Step 1. We hash the Passphrase using MD5
// We use the MD5 hash generator as the result is a 128 bit byte array
// which is a valid length for the Triple DES encoder we use below
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = HashProvider.ComputeHash( UTF8.GetBytes( Password ) );
// Step 2. Create a new TripleDESCryptoServiceProvider object
// Step 3. Setup the encoder
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
// Step 4. Convert the input string to a byte[]
byte[] DataToEncrypt = UTF8.GetBytes( Message );
// Step 5. Attempt to encrypt the string
try {
ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
Results = Encryptor.TransformFinalBlock( DataToEncrypt, 0, DataToEncrypt.Length );
} finally {
// Clear the Triple Des and Hashprovider services of any sensitive information
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
// Step 6. Return the encrypted string as a base64 encoded string
return Convert.ToBase64String( Results );
}
#endregion
#region "Decrypt"
// Decrypt using Password from Property (pre-hashed)
public string Decrypt( string Message ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = this.bPassword;
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
byte[] DataToDecrypt = Convert.FromBase64String( Message );
try {
ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
Results = Decryptor.TransformFinalBlock( DataToDecrypt, 0, DataToDecrypt.Length );
} finally {
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
return UTF8.GetString( Results );
}
// Decrypt using Password as Byte array
public string Decrypt( string Message, byte[] Password ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = HashProvider.ComputeHash( UTF8.GetBytes( UTF8.GetString( Password ) ) );
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
byte[] DataToDecrypt = Convert.FromBase64String( Message );
try {
ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
Results = Decryptor.TransformFinalBlock( DataToDecrypt, 0, DataToDecrypt.Length );
} finally {
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
return UTF8.GetString( Results );
}
// Decrypt using Password as string
public string Decrypt( string Message, string Password ) {
byte[] Results = null;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
// Step 1. We hash the pass phrase using MD5
// We use the MD5 hash generator as the result is a 128-bit byte array
// which is a valid length for the Triple DES encoder we use below
using ( MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider() ) {
byte[] TDESKey = HashProvider.ComputeHash( UTF8.GetBytes( Password ) );
// Step 2. Create a new TripleDESCryptoServiceProvider object
// Step 3. Setup the decoder
using ( TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider { Key = TDESKey, Mode = CipherMode.ECB, Padding = PaddingMode.PKCS7 } ) {
// Step 4. Convert the input string to a byte[]
byte[] DataToDecrypt = Convert.FromBase64String( Message );
// Step 5. Attempt to decrypt the string
try {
ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
Results = Decryptor.TransformFinalBlock( DataToDecrypt, 0, DataToDecrypt.Length );
} finally {
// Clear the Triple Des and Hash provider services of any sensitive information
TDESAlgorithm.Clear();
HashProvider.Clear();
}
}
}
// Step 6. Return the decrypted string in UTF8 format
return UTF8.GetString( Results );
}
#endregion
}
Problem
I am trying to write a function in PHP and in VB.NET that uses Triple DES to pass in BOTH directions encrypted data. The problem, is that when I try to decrypt a string encrypted in VB.NET using PHP, I get an error message saying that the block size of the IV must match. The class I wrote in VB.NET, is as follows and is fully functional as it will encrypt and decrypt its own blocks flawlessly. ``` Imports System Imports System.Text Imports System.IO Imports System.Security.Cryptography Public Class Cipher Dim method As TripleDESCryptoServiceProvider Dim key As Byte() Public Property Password() As String Get Return System.Text.Encoding.Unicode.GetString(Key) End Get Set(value As String) key = System.Text.Encoding.Unicode.GetBytes(value) End Set End Property Public Function Encrypt(data As String) As String Dim ms As New System.IO.MemoryStream ' Create the encoder to write to the stream. Dim dataBytes() As Byte = System.Text.Encoding.Unicode.GetBytes(data) Dim encStream As New CryptoStream(ms, method.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write) ' Use the crypto stream to write the byte array to the stream. encStream.Write(dataBytes, 0, dataBytes.Length) encStream.FlushFinalBlock() ' IV and Ciphered string are each Base64'd and seperated by a comma, then the whole result is Base64'd Return Convert.ToBase64String(System.Text.Encoding.Unicode.GetBytes(Convert.ToBase64String(method.IV) & "," & Convert.ToBase64String(ms.ToArray))) End Function Public Function Decrypt(data As String) As String ' Convert the encrypted text string to a byte array. Dim partDecoded As String = System.Text.Encoding.Unicode.GetString(Convert.FromBase64String(data)) Dim dataBytes() As Byte If InStr(partDecoded, ",") > 0 Then Dim parts() As String = Split(partDecoded, ",") ' Get IV from first part method.IV = Convert.FromBase64String(parts(0)) ' Get ciphered data from second part dataBytes = Convert.FromBase64String(parts(1)) ' Create the stream. Dim ms As New System.IO.MemoryStream ' Create the decoder to write to the stream. Dim decStream As New CryptoStream(ms, method.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Write) ' Use the crypto stream to write the byte array to the stream. decStream.Write(dataBytes, 0, dataBytes.Length) decStream.FlushFinalBlock() ' Convert the plaintext stream to a string. Return System.Text.Encoding.Unicode.GetString(ms.ToArray) Else Return False End If End Function Public Sub New() method = New TripleDESCryptoServiceProvider method.Mode = CipherMode.CFB method.GenerateIV() End Sub End Class ``` Example usage of the above class ``` Dim c As New Cipher c.Password = "12345" Dim encrypted As String = c.Encrypt("hello") Debug.Print(encrypted) Dim decrypted As String = c.Decrypt(encrypted) Debug.Print(decrypted) ``` Now I also have the following PHP code which ALSO works (by itself) ``` class Cipher { private $iv; private $securekey; function __construct($key) { $this->securekey = $key; } function encrypt($string) { $this->iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_3DES, MCRYPT_MODE_CFB),MCRYPT_DEV_RANDOM); $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_3DES, $this->securekey, $string, MCRYPT_MODE_CFB, $this->iv)); return base64_encode(base64_encode($this->iv) . ',' . $encrypted); } function decrypt($string) { $decrypt = base64_decode($string); if(strpos($decrypt,',') > 0) { $decrypt = explode(',', $decrypt); $this->iv = base64_decode($decrypt[0]); return trim(mcrypt_decrypt(MCRYPT_3DES, $this->securekey, base64_decode($decrypt[1]), MCRYPT_MODE_CFB, $this->iv)); } else { return false; } } } ``` PHP Example Usage ``` $c = new Cipher("12345"); $encrypted = $c->encrypt("hello"); echo 'Encrypted: ' . $encrypted . '<br />'; $decrypted = $c->decrypt($encrypted); echo 'Decrypted: ' . $decrypted . '<br />'; $vb = "MwBOAEoAOQBjAEgAcQAyAC8ASABzAD0ALABmAEUAOQBaAHYAVwBzAFUAYQB3AFYARwBGAHUANABLAGUAVgB3AFcAaABRAD0APQA="; echo 'VB.NET Dec: ' . $c->decrypt($vb); ``` What I have included above in the PHP usage, is the Base64 string made with VB.NET that decodes PERFECTLY in VB.NET as the variable $vb. This is driving me absolutely batty, as the code is correct, and functional -- in both cases -- so what am I missing and can you point out / fix the problem. I do not wish to use Rijndael, or explore other cipher methods, as this one is well established that works across multiple devices natively (iOS, Android, Windows, Linux, etc.).