VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "clsDES"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
'DES Encryption/Decryption Class
'------------------------------------
'
'Information concerning the DES
'algorithm can be found at:
'http://csrc.nist.gov/fips/fips46-3.pdf
'
'(c) 2000, Fredrik Qvarfort
'

Option Explicit

'For progress notifications
Event Progress(Percent As Long)

'Key-dependant
Private m_Key(0 To 47, 1 To 16) As Byte

'Buffered key value
Private m_KeyValue As String

'Values given in the DES standard
Private m_E(0 To 63) As Byte
Private m_P(0 To 31) As Byte
Private m_IP(0 To 63) As Byte
Private m_PC1(0 To 55) As Byte
Private m_PC2(0 To 47) As Byte
Private m_IPInv(0 To 63) As Byte
Private m_EmptyArray(0 To 63) As Byte
Private m_LeftShifts(1 To 16) As Byte
Private m_sBox(0 To 7, 0 To 1, 0 To 1, 0 To 1, 0 To 1, 0 To 1, 0 To 1) As Long

Private Declare Sub CopyMem Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)
Private Static Sub Byte2Bin(ByteArray() As Byte, ByteLen As Long, BinaryArray() As Byte)

  Dim a As Long
  Dim ByteValue As Byte
  Dim BinLength As Long
  
  'Clear the destination array, faster than
  'setting the data to zero in the loop below
  Call CopyMem(BinaryArray(0), m_EmptyArray(0), ByteLen * 8)
  
  'Add binary 1's where needed
  BinLength = 0
  For a = 0 To (ByteLen - 1)
    ByteValue = ByteArray(a)
    If (ByteValue And 128) Then BinaryArray(BinLength) = 1
    If (ByteValue And 64) Then BinaryArray(BinLength + 1) = 1
    If (ByteValue And 32) Then BinaryArray(BinLength + 2) = 1
    If (ByteValue And 16) Then BinaryArray(BinLength + 3) = 1
    If (ByteValue And 8) Then BinaryArray(BinLength + 4) = 1
    If (ByteValue And 4) Then BinaryArray(BinLength + 5) = 1
    If (ByteValue And 2) Then BinaryArray(BinLength + 6) = 1
    If (ByteValue And 1) Then BinaryArray(BinLength + 7) = 1
    BinLength = BinLength + 8
  Next

End Sub
Private Static Sub Bin2Byte(BinaryArray() As Byte, ByteLen As Long, ByteArray() As Byte)

  Dim a As Long
  Dim ByteValue As Byte
  Dim BinLength As Long
  
  'Calculate byte values
  BinLength = 0
  For a = 0 To (ByteLen - 1)
    ByteValue = 0
    If (BinaryArray(BinLength) = 1) Then ByteValue = ByteValue + 128
    If (BinaryArray(BinLength + 1) = 1) Then ByteValue = ByteValue + 64
    If (BinaryArray(BinLength + 2) = 1) Then ByteValue = ByteValue + 32
    If (BinaryArray(BinLength + 3) = 1) Then ByteValue = ByteValue + 16
    If (BinaryArray(BinLength + 4) = 1) Then ByteValue = ByteValue + 8
    If (BinaryArray(BinLength + 5) = 1) Then ByteValue = ByteValue + 4
    If (BinaryArray(BinLength + 6) = 1) Then ByteValue = ByteValue + 2
    If (BinaryArray(BinLength + 7) = 1) Then ByteValue = ByteValue + 1
    ByteArray(a) = ByteValue
    BinLength = BinLength + 8
  Next
  
End Sub
Private Static Sub EncryptBlock(BlockData() As Byte)

  Dim a As Long
  Dim i As Long
  Dim L(0 To 31) As Byte
  Dim R(0 To 31) As Byte
  Dim RL(0 To 63) As Byte
  Dim sBox(0 To 31) As Byte
  Dim LiRi(0 To 31) As Byte
  Dim ERxorK(0 To 47) As Byte
  Dim BinBlock(0 To 63) As Byte
  
  'Convert the block into a binary array
  '(I do believe this is the best solution
  'in VB for the DES algorithm, but it is
  'still slow as xxxx)
  Call Byte2Bin(BlockData(), 8, BinBlock())
  
  'Apply the IP permutation and split the
  'block into two halves, L[] and R[]
  For a = 0 To 31
    L(a) = BinBlock(m_IP(a))
    R(a) = BinBlock(m_IP(a + 32))
  Next
  
  'Apply the 16 subkeys on the block
  For i = 1 To 16
    'E(R[i]) xor K[i]
    ERxorK(0) = R(31) Xor m_Key(0, i)
    ERxorK(1) = R(0) Xor m_Key(1, i)
    ERxorK(2) = R(1) Xor m_Key(2, i)
    ERxorK(3) = R(2) Xor m_Key(3, i)
    ERxorK(4) = R(3) Xor m_Key(4, i)
    ERxorK(5) = R(4) Xor m_Key(5, i)
    ERxorK(6) = R(3) Xor m_Key(6, i)
    ERxorK(7) = R(4) Xor m_Key(7, i)
    ERxorK(8) = R(5) Xor m_Key(8, i)
    ERxorK(9) = R(6) Xor m_Key(9, i)
    ERxorK(10) = R(7) Xor m_Key(10, i)
    ERxorK(11) = R(8) Xor m_Key(11, i)
    ERxorK(12) = R(7) Xor m_Key(12, i)
    ERxorK(13) = R(8) Xor m_Key(13, i)
    ERxorK(14) = R(9) Xor m_Key(14, i)
    ERxorK(15) = R(10) Xor m_Key(15, i)
    ERxorK(16) = R(11) Xor m_Key(16, i)
    ERxorK(17) = R(12) Xor m_Key(17, i)
    ERxorK(18) = R(11) Xor m_Key(18, i)
    ERxorK(19) = R(12) Xor m_Key(19, i)
    ERxorK(20) = R(13) Xor m_Key(20, i)
    ERxorK(21) = R(14) Xor m_Key(21, i)
    ERxorK(22) = R(15) Xor m_Key(22, i)
    ERxorK(23) = R(16) Xor m_Key(23, i)
    ERxorK(24) = R(15) Xor m_Key(24, i)
    ERxorK(25) = R(16) Xor m_Key(25, i)
    ERxorK(26) = R(17) Xor m_Key(26, i)
    ERxorK(27) = R(18) Xor m_Key(27, i)
    ERxorK(28) = R(19) Xor m_Key(28, i)
    ERxorK(29) = R(20) Xor m_Key(29, i)
    ERxorK(30) = R(19) Xor m_Key(30, i)
    ERxorK(31) = R(20) Xor m_Key(31, i)
    ERxorK(32) = R(21) Xor m_Key(32, i)
    ERxorK(33) = R(22) Xor m_Key(33, i)
    ERxorK(34) = R(23) Xor m_Key(34, i)
    ERxorK(35) = R(24) Xor m_Key(35, i)
    ERxorK(36) = R(23) Xor m_Key(36, i)
    ERxorK(37) = R(24) Xor m_Key(37, i)
    ERxorK(38) = R(25) Xor m_Key(38, i)
    ERxorK(39) = R(26) Xor m_Key(39, i)
    ERxorK(40) = R(27) Xor m_Key(40, i)
    ERxorK(41) = R(28) Xor m_Key(41, i)
    ERxorK(42) = R(27) Xor m_Key(42, i)
    ERxorK(43) = R(28) Xor m_Key(43, i)
    ERxorK(44) = R(29) Xor m_Key(44, i)
    ERxorK(45) = R(30) Xor m_Key(45, i)
    ERxorK(46) = R(31) Xor m_Key(46, i)
    ERxorK(47) = R(0) Xor m_Key(47, i)
    
    'Apply the s-boxes
    Call CopyMem(sBox(0), m_sBox(0, ERxorK(0), ERxorK(1), ERxorK(2), ERxorK(3), ERxorK(4), ERxorK(5)), 4)
    Call CopyMem(sBox(4), m_sBox(1, ERxorK(6), ERxorK(7), ERxorK(8), ERxorK(9), ERxorK(10), ERxorK(11)), 4)
    Call CopyMem(sBox(8), m_sBox(2, ERxorK(12), ERxorK(13), ERxorK(14), ERxorK(15), ERxorK(16), ERxorK(17)), 4)
    Call CopyMem(sBox(12), m_sBox(3, ERxorK(18), ERxorK(19), ERxorK(20), ERxorK(21), ERxorK(22), ERxorK(23)), 4)
    Call CopyMem(sBox(16), m_sBox(4, ERxorK(24), ERxorK(25), ERxorK(26), ERxorK(27), ERxorK(28), ERxorK(29)), 4)
    Call CopyMem(sBox(20), m_sBox(5, ERxorK(30), ERxorK(31), ERxorK(32), ERxorK(33), ERxorK(34), ERxorK(35)), 4)
    Call CopyMem(sBox(24), m_sBox(6, ERxorK(36), ERxorK(37), ERxorK(38), ERxorK(39), ERxorK(40), ERxorK(41)), 4)
    Call CopyMem(sBox(28), m_sBox(7, ERxorK(42), ERxorK(43), ERxorK(44), ERxorK(45), ERxorK(46), ERxorK(47)), 4)
    
    'L[i] xor P(R[i])
    LiRi(0) = L(0) Xor sBox(15)
    LiRi(1) = L(1) Xor sBox(6)
    LiRi(2) = L(2) Xor sBox(19)
    LiRi(3) = L(3) Xor sBox(20)
    LiRi(4) = L(4) Xor sBox(28)
    LiRi(5) = L(5) Xor sBox(11)
    LiRi(6) = L(6) Xor sBox(27)
    LiRi(7) = L(7) Xor sBox(16)
    LiRi(8) = L(8) Xor sBox(0)
    LiRi(9) = L(9) Xor sBox(14)
    LiRi(10) = L(10) Xor sBox(22)
    LiRi(11) = L(11) Xor sBox(25)
    LiRi(12) = L(12) Xor sBox(4)
    LiRi(13) = L(13) Xor sBox(17)
    LiRi(14) = L(14) Xor sBox(30)
    LiRi(15) = L(15) Xor sBox(9)
    LiRi(16) = L(16) Xor sBox(1)
    LiRi(17) = L(17) Xor sBox(7)
    LiRi(18) = L(18) Xor sBox(23)
    LiRi(19) = L(19) Xor sBox(13)
    LiRi(20) = L(20) Xor sBox(31)
    LiRi(21) = L(21) Xor sBox(26)
    LiRi(22) = L(22) Xor sBox(2)
    LiRi(23) = L(23) Xor sBox(8)
    LiRi(24) = L(24) Xor sBox(18)
    LiRi(25) = L(25) Xor sBox(12)
    LiRi(26) = L(26) Xor sBox(29)
    LiRi(27) = L(27) Xor sBox(5)
    LiRi(28) = L(28) Xor sBox(21)
    LiRi(29) = L(29) Xor sBox(10)
    LiRi(30) = L(30) Xor sBox(3)
    LiRi(31) = L(31) Xor sBox(24)
    
    'Prepare for next round
    Call CopyMem(L(0), R(0), 32)
    Call CopyMem(R(0), LiRi(0), 32)
  Next
  
  'Concatenate R[]L[]
  Call CopyMem(RL(0), R(0), 32)
  Call CopyMem(RL(32), L(0), 32)

  'Apply the invIP permutation
  For a = 0 To 63
    BinBlock(a) = RL(m_IPInv(a))
  Next
  
  'Convert the binaries into a byte array
  Call Bin2Byte(BinBlock(), 8, BlockData())

End Sub
Private Static Sub DecryptBlock(BlockData() As Byte)

  Dim a As Long
  Dim i As Long
  Dim L(0 To 31) As Byte
  Dim R(0 To 31) As Byte
  Dim RL(0 To 63) As Byte
  Dim sBox(0 To 31) As Byte
  Dim LiRi(0 To 31) As Byte
  Dim ERxorK(0 To 47) As Byte
  Dim BinBlock(0 To 63) As Byte
  
  'Convert the block into a binary array
  '(I do believe this is the best solution
  'in VB for the DES algorithm, but it is
  'still slow as xxxx)
  Call Byte2Bin(BlockData(), 8, BinBlock())
  
  'Apply the IP permutation and split the
  'block into two halves, L[] and R[]
  For a = 0 To 31
    L(a) = BinBlock(m_IP(a))
    R(a) = BinBlock(m_IP(a + 32))
  Next
  
  'Apply the 16 subkeys on the block
  For i = 16 To 1 Step -1
    'E(R[i]) xor K[i]
    ERxorK(0) = R(31) Xor m_Key(0, i)
    ERxorK(1) = R(0) Xor m_Key(1, i)
    ERxorK(2) = R(1) Xor m_Key(2, i)
    ERxorK(3) = R(2) Xor m_Key(3, i)
    ERxorK(4) = R(3) Xor m_Key(4, i)
    ERxorK(5) = R(4) Xor m_Key(5, i)
    ERxorK(6) = R(3) Xor m_Key(6, i)
    ERxorK(7) = R(4) Xor m_Key(7, i)
    ERxorK(8) = R(5) Xor m_Key(8, i)
    ERxorK(9) = R(6) Xor m_Key(9, i)
    ERxorK(10) = R(7) Xor m_Key(10, i)
    ERxorK(11) = R(8) Xor m_Key(11, i)
    ERxorK(12) = R(7) Xor m_Key(12, i)
    ERxorK(13) = R(8) Xor m_Key(13, i)
    ERxorK(14) = R(9) Xor m_Key(14, i)
    ERxorK(15) = R(10) Xor m_Key(15, i)
    ERxorK(16) = R(11) Xor m_Key(16, i)
    ERxorK(17) = R(12) Xor m_Key(17, i)
    ERxorK(18) = R(11) Xor m_Key(18, i)
    ERxorK(19) = R(12) Xor m_Key(19, i)
    ERxorK(20) = R(13) Xor m_Key(20, i)
    ERxorK(21) = R(14) Xor m_Key(21, i)
    ERxorK(22) = R(15) Xor m_Key(22, i)
    ERxorK(23) = R(16) Xor m_Key(23, i)
    ERxorK(24) = R(15) Xor m_Key(24, i)
    ERxorK(25) = R(16) Xor m_Key(25, i)
    ERxorK(26) = R(17) Xor m_Key(26, i)
    ERxorK(27) = R(18) Xor m_Key(27, i)
    ERxorK(28) = R(19) Xor m_Key(28, i)
    ERxorK(29) = R(20) Xor m_Key(29, i)
    ERxorK(30) = R(19) Xor m_Key(30, i)
    ERxorK(31) = R(20) Xor m_Key(31, i)
    ERxorK(32) = R(21) Xor m_Key(32, i)
    ERxorK(33) = R(22) Xor m_Key(33, i)
    ERxorK(34) = R(23) Xor m_Key(34, i)
    ERxorK(35) = R(24) Xor m_Key(35, i)
    ERxorK(36) = R(23) Xor m_Key(36, i)
    ERxorK(37) = R(24) Xor m_Key(37, i)
    ERxorK(38) = R(25) Xor m_Key(38, i)
    ERxorK(39) = R(26) Xor m_Key(39, i)
    ERxorK(40) = R(27) Xor m_Key(40, i)
    ERxorK(41) = R(28) Xor m_Key(41, i)
    ERxorK(42) = R(27) Xor m_Key(42, i)
    ERxorK(43) = R(28) Xor m_Key(43, i)
    ERxorK(44) = R(29) Xor m_Key(44, i)
    ERxorK(45) = R(30) Xor m_Key(45, i)
    ERxorK(46) = R(31) Xor m_Key(46, i)
    ERxorK(47) = R(0) Xor m_Key(47, i)
    
    'Apply the s-boxes
    Call CopyMem(sBox(0), m_sBox(0, ERxorK(0), ERxorK(1), ERxorK(2), ERxorK(3), ERxorK(4), ERxorK(5)), 4)
    Call CopyMem(sBox(4), m_sBox(1, ERxorK(6), ERxorK(7), ERxorK(8), ERxorK(9), ERxorK(10), ERxorK(11)), 4)
    Call CopyMem(sBox(8), m_sBox(2, ERxorK(12), ERxorK(13), ERxorK(14), ERxorK(15), ERxorK(16), ERxorK(17)), 4)
    Call CopyMem(sBox(12), m_sBox(3, ERxorK(18), ERxorK(19), ERxorK(20), ERxorK(21), ERxorK(22), ERxorK(23)), 4)
    Call CopyMem(sBox(16), m_sBox(4, ERxorK(24), ERxorK(25), ERxorK(26), ERxorK(27), ERxorK(28), ERxorK(29)), 4)
    Call CopyMem(sBox(20), m_sBox(5, ERxorK(30), ERxorK(31), ERxorK(32), ERxorK(33), ERxorK(34), ERxorK(35)), 4)
    Call CopyMem(sBox(24), m_sBox(6, ERxorK(36), ERxorK(37), ERxorK(38), ERxorK(39), ERxorK(40), ERxorK(41)), 4)
    Call CopyMem(sBox(28), m_sBox(7, ERxorK(42), ERxorK(43), ERxorK(44), ERxorK(45), ERxorK(46), ERxorK(47)), 4)
    
    'L[i] xor P(R[i])
    LiRi(0) = L(0) Xor sBox(15)
    LiRi(1) = L(1) Xor sBox(6)
    LiRi(2) = L(2) Xor sBox(19)
    LiRi(3) = L(3) Xor sBox(20)
    LiRi(4) = L(4) Xor sBox(28)
    LiRi(5) = L(5) Xor sBox(11)
    LiRi(6) = L(6) Xor sBox(27)
    LiRi(7) = L(7) Xor sBox(16)
    LiRi(8) = L(8) Xor sBox(0)
    LiRi(9) = L(9) Xor sBox(14)
    LiRi(10) = L(10) Xor sBox(22)
    LiRi(11) = L(11) Xor sBox(25)
    LiRi(12) = L(12) Xor sBox(4)
    LiRi(13) = L(13) Xor sBox(17)
    LiRi(14) = L(14) Xor sBox(30)
    LiRi(15) = L(15) Xor sBox(9)
    LiRi(16) = L(16) Xor sBox(1)
    LiRi(17) = L(17) Xor sBox(7)
    LiRi(18) = L(18) Xor sBox(23)
    LiRi(19) = L(19) Xor sBox(13)
    LiRi(20) = L(20) Xor sBox(31)
    LiRi(21) = L(21) Xor sBox(26)
    LiRi(22) = L(22) Xor sBox(2)
    LiRi(23) = L(23) Xor sBox(8)
    LiRi(24) = L(24) Xor sBox(18)
    LiRi(25) = L(25) Xor sBox(12)
    LiRi(26) = L(26) Xor sBox(29)
    LiRi(27) = L(27) Xor sBox(5)
    LiRi(28) = L(28) Xor sBox(21)
    LiRi(29) = L(29) Xor sBox(10)
    LiRi(30) = L(30) Xor sBox(3)
    LiRi(31) = L(31) Xor sBox(24)
    
    'Prepare for next round
    Call CopyMem(L(0), R(0), 32)
    Call CopyMem(R(0), LiRi(0), 32)
  Next
  
  'Concatenate R[]L[]
  Call CopyMem(RL(0), R(0), 32)
  Call CopyMem(RL(32), L(0), 32)

  'Apply the invIP permutation
  For a = 0 To 63
    BinBlock(a) = RL(m_IPInv(a))
  Next
  
  'Convert the binaries into a byte array
  Call Bin2Byte(BinBlock(), 8, BlockData())

End Sub

Public Sub EncryptByte(ByteArray() As Byte, Optional Key As String)

  Dim a As Long
  Dim Offset As Long
  Dim OrigLen As Long
  Dim CipherLen As Long
  Dim CurrPercent As Long
  Dim NextPercent As Long
  Dim CurrBlock(0 To 7) As Byte
  Dim CipherBlock(0 To 7) As Byte
  
  'Set the key if provided
  If (Len(Key) > 0) Then Me.Key = Key
  
  'Get the size of the original array
  OrigLen = UBound(ByteArray) + 1
  
  'First we add 12 bytes (4 bytes for the
  'length and 8 bytes for the seed values
  'for the CBC routine), and the ciphertext
  'must be a multiple of 8 bytes
  CipherLen = OrigLen + 12
  If (CipherLen Mod 8 <> 0) Then
    CipherLen = CipherLen + 8 - (CipherLen Mod 8)
  End If
  ReDim Preserve ByteArray(CipherLen - 1)
  Call CopyMem(ByteArray(12), ByteArray(0), OrigLen)
  
  'Store the length descriptor in bytes [9-12]
  Call CopyMem(ByteArray(8), OrigLen, 4)
  
  'Store a block of random data in bytes [1-8],
  'these work as seed values for the CBC routine
  'and is used to produce different ciphertext
  'even when encrypting the same data with the
  'same key)
  Call Randomize
  Call CopyMem(ByteArray(0), CLng(2147483647 * Rnd), 4)
  Call CopyMem(ByteArray(4), CLng(2147483647 * Rnd), 4)
  
  'Encrypt the data in 64-bit blocks
  For Offset = 0 To (CipherLen - 1) Step 8
    'Get the next block of plaintext
    Call CopyMem(CurrBlock(0), ByteArray(Offset), 8)
    
    'XOR the plaintext with the previous
    'ciphertext (CBC, Cipher-Block Chaining)
    For a = 0 To 7
      CurrBlock(a) = CurrBlock(a) Xor CipherBlock(a)
    Next
    
    'Encrypt the block
    Call EncryptBlock(CurrBlock())