www.pudn.com > 020827_encryp.zip > clsDES.cls
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())
'Store the block
Call CopyMem(ByteArray(Offset), CurrBlock(0), 8)
'Store the cipherblock (for CBC)
Call CopyMem(CipherBlock(0), CurrBlock(0), 8)
'Update the progress if neccessary
If (Offset >= NextPercent) Then
CurrPercent = Int((Offset / CipherLen) * 100)
NextPercent = (CipherLen * ((CurrPercent + 1) / 100)) + 1
RaiseEvent Progress(CurrPercent)
End If
Next
'Make sure we return a 100% progress
If (CurrPercent <> 100) Then RaiseEvent Progress(100)
End Sub
Public Sub DecryptByte(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 new key if provided
If (Len(Key) > 0) Then Me.Key = Key
'Get the size of the ciphertext
CipherLen = UBound(ByteArray) + 1
'Decrypt the data in 64-bit blocks
For Offset = 0 To (CipherLen - 1) Step 8
'Get the next block of ciphertext
Call CopyMem(CurrBlock(0), ByteArray(Offset), 8)
'Decrypt the block
Call DecryptBlock(CurrBlock())
'XOR with the previous cipherblock
For a = 0 To 7
CurrBlock(a) = CurrBlock(a) Xor CipherBlock(a)
Next
'Store the current ciphertext to use
'XOR with the next block plaintext
Call CopyMem(CipherBlock(0), ByteArray(Offset), 8)
'Store the block
Call CopyMem(ByteArray(Offset), CurrBlock(0), 8)
'Update the progress if neccessary
If (Offset >= NextPercent) Then
CurrPercent = Int((Offset / CipherLen) * 100)
NextPercent = (CipherLen * ((CurrPercent + 1) / 100)) + 1
RaiseEvent Progress(CurrPercent)
End If
Next
'Get the size of the original array
Call CopyMem(OrigLen, ByteArray(8), 4)
'Make sure OrigLen is a reasonable value,
'if we used the wrong key the next couple
'of statements could be dangerous (GPF)
If (CipherLen - OrigLen > 19) Or (CipherLen - OrigLen < 12) Then
Call Err.Raise(vbObjectError, , "Incorrect size descriptor in DES decryption")
End If
'Resize the bytearray to hold only the plaintext
'and not the extra information added by the
'encryption routine
Call CopyMem(ByteArray(0), ByteArray(12), OrigLen)
ReDim Preserve ByteArray(OrigLen - 1)
'Make sure we return a 100% progress
If (CurrPercent <> 100) Then RaiseEvent Progress(100)
End Sub
Public Sub EncryptFile(SourceFile As String, DestFile As String, Optional Key As String)
Dim Filenr As Integer
Dim ByteArray() As Byte
'Make sure the source file do exist
If (Not FileExist(SourceFile)) Then
Call Err.Raise(vbObjectError, , "Error in Skipjack EncryptFile procedure (Source file does not exist).")
Exit Sub
End If
'Open the source file and read the content
'into a bytearray to pass onto encryption
Filenr = FreeFile
Open SourceFile For Binary As #Filenr
ReDim ByteArray(0 To LOF(Filenr) - 1)
Get #Filenr, , ByteArray()
Close #Filenr
'Encrypt the bytearray
Call EncryptByte(ByteArray(), Key)
'If the destination file already exist we need
'to delete it since opening it for binary use
'will preserve it if it already exist
If (FileExist(DestFile)) Then Kill DestFile
'Store the encrypted data in the destination file
Filenr = FreeFile
Open DestFile For Binary As #Filenr
Put #Filenr, , ByteArray()
Close #Filenr
End Sub
Public Sub DecryptFile(SourceFile As String, DestFile As String, Optional Key As String)
Dim Filenr As Integer
Dim ByteArray() As Byte
'Make sure the source file do exist
If (Not FileExist(SourceFile)) Then
Call Err.Raise(vbObjectError, , "Error in Skipjack EncryptFile procedure (Source file does not exist).")
Exit Sub
End If
'Open the source file and read the content
'into a bytearray to decrypt
Filenr = FreeFile
Open SourceFile For Binary As #Filenr
ReDim ByteArray(0 To LOF(Filenr) - 1)
Get #Filenr, , ByteArray()
Close #Filenr
'Decrypt the bytearray
Call DecryptByte(ByteArray(), Key)
'If the destination file already exist we need
'to delete it since opening it for binary use
'will preserve it if it already exist
If (FileExist(DestFile)) Then Kill DestFile
'Store the decrypted data in the destination file
Filenr = FreeFile
Open DestFile For Binary As #Filenr
Put #Filenr, , ByteArray()
Close #Filenr
End Sub
Public Function EncryptString(Text As String, Optional Key As String) As String
Dim ByteArray() As Byte
'Convert the text into a byte array
ByteArray() = StrConv(Text, vbFromUnicode)
'Encrypt the byte array
Call EncryptByte(ByteArray(), Key)
'Convert the byte array back to a string
EncryptString = StrConv(ByteArray(), vbUnicode)
End Function
Public Function DecryptString(Text As String, Optional Key As String) As String
Dim ByteArray() As Byte
'Convert the text into a byte array
ByteArray() = StrConv(Text, vbFromUnicode)
'Encrypt the byte array
Call DecryptByte(ByteArray(), Key)
'Convert the byte array back to a string
DecryptString = StrConv(ByteArray(), vbUnicode)
End Function
Public Property Let Key(New_Value As String)
Dim a As Long
Dim i As Long
Dim C(0 To 27) As Byte
Dim D(0 To 27) As Byte
Dim K(0 To 55) As Byte
Dim CD(0 To 55) As Byte
Dim Temp(0 To 1) As Byte
Dim KeyBin(0 To 63) As Byte
Dim KeySchedule(0 To 63) As Byte
'Do nothing if the key is buffered
If (m_KeyValue = New_Value) Then Exit Property
'Store a string value of the buffered key
m_KeyValue = New_Value
'Convert the key to a binary array
Call Byte2Bin(StrConv(New_Value, vbFromUnicode), IIf(Len(New_Value) > 8, 8, Len(New_Value)), KeyBin())
'Apply the PC-2 permutation
For a = 0 To 55
KeySchedule(a) = KeyBin(m_PC1(a))
Next
'Split keyschedule into two halves, C[] and D[]
Call CopyMem(C(0), KeySchedule(0), 28)
Call CopyMem(D(0), KeySchedule(28), 28)
'Calculate the key schedule (16 subkeys)
For i = 1 To 16
'Perform one or two cyclic left shifts on
'both C[i-1] and D[i-1] to get C[i] and D[i]
Call CopyMem(Temp(0), C(0), m_LeftShifts(i))
Call CopyMem(C(0), C(m_LeftShifts(i)), 28 - m_LeftShifts(i))
Call CopyMem(C(28 - m_LeftShifts(i)), Temp(0), m_LeftShifts(i))
Call CopyMem(Temp(0), D(0), m_LeftShifts(i))
Call CopyMem(D(0), D(m_LeftShifts(i)), 28 - m_LeftShifts(i))
Call CopyMem(D(28 - m_LeftShifts(i)), Temp(0), m_LeftShifts(i))
'Concatenate C[] and D[]
Call CopyMem(CD(0), C(0), 28)
Call CopyMem(CD(28), D(0), 28)
'Apply the PC-2 permutation and store
'the calculated subkey
For a = 0 To 47
m_Key(a, i) = CD(m_PC2(a))
Next
Next
End Property
Private Sub Class_Initialize()
Dim i As Long
Dim vE As Variant
Dim vP As Variant
Dim vIP As Variant
Dim vPC1 As Variant
Dim vPC2 As Variant
Dim vIPInv As Variant
Dim vSbox(0 To 7) As Variant
'Initialize the permutation IP
vIP = Array(58, 50, 42, 34, 26, 18, 10, 2, _
60, 52, 44, 36, 28, 20, 12, 4, _
62, 54, 46, 38, 30, 22, 14, 6, _
64, 56, 48, 40, 32, 24, 16, 8, _
57, 49, 41, 33, 25, 17, 9, 1, _
59, 51, 43, 35, 27, 19, 11, 3, _
61, 53, 45, 37, 29, 21, 13, 5, _
63, 55, 47, 39, 31, 23, 15, 7)
'Create the permutation IP
For i = LBound(vIP) To UBound(vIP)
m_IP(i) = (vIP(i) - 1)
Next
'Initialize the expansion function E
vE = Array(32, 1, 2, 3, 4, 5, _
4, 5, 6, 7, 8, 9, _
8, 9, 10, 11, 12, 13, _
12, 13, 14, 15, 16, 17, _
16, 17, 18, 19, 20, 21, _
20, 21, 22, 23, 24, 25, _
24, 25, 26, 27, 28, 29, _
28, 29, 30, 31, 32, 1)
'Create the expansion array
For i = LBound(vE) To UBound(vE)
m_E(i) = (vE(i) - 1)
Next
'Initialize the PC1 function
vPC1 = Array(57, 49, 41, 33, 25, 17, 9, _
1, 58, 50, 42, 34, 26, 18, _
10, 2, 59, 51, 43, 35, 27, _
19, 11, 3, 60, 52, 44, 36, _
63, 55, 47, 39, 31, 23, 15, _
7, 62, 54, 46, 38, 30, 22, _
14, 6, 61, 53, 45, 37, 29, _
21, 13, 5, 28, 20, 12, 4)
'Create the PC1 function
For i = LBound(vPC1) To UBound(vPC1)
m_PC1(i) = (vPC1(i) - 1)
Next
'Initialize the PC2 function
vPC2 = Array(14, 17, 11, 24, 1, 5, _
3, 28, 15, 6, 21, 10, _
23, 19, 12, 4, 26, 8, _
16, 7, 27, 20, 13, 2, _
41, 52, 31, 37, 47, 55, _
30, 40, 51, 45, 33, 48, _
44, 49, 39, 56, 34, 53, _
46, 42, 50, 36, 29, 32)
'Create the PC2 function
For i = LBound(vPC2) To UBound(vPC2)
m_PC2(i) = (vPC2(i) - 1)
Next
'Initialize the inverted IP
vIPInv = Array(40, 8, 48, 16, 56, 24, 64, 32, _
39, 7, 47, 15, 55, 23, 63, 31, _
38, 6, 46, 14, 54, 22, 62, 30, _
37, 5, 45, 13, 53, 21, 61, 29, _
36, 4, 44, 12, 52, 20, 60, 28, _
35, 3, 43, 11, 51, 19, 59, 27, _
34, 2, 42, 10, 50, 18, 58, 26, _
33, 1, 41, 9, 49, 17, 57, 25)
'Create the inverted IP
For i = LBound(vIPInv) To UBound(vIPInv)
m_IPInv(i) = (vIPInv(i) - 1)
Next
'Initialize permutation P
vP = Array(16, 7, 20, 21, _
29, 12, 28, 17, _
1, 15, 23, 26, _
5, 18, 31, 10, _
2, 8, 24, 14, _
32, 27, 3, 9, _
19, 13, 30, 6, _
22, 11, 4, 25)
'Create P
For i = LBound(vP) To UBound(vP)
m_P(i) = (vP(i) - 1)
Next
'Initialize the leftshifts array
For i = 1 To 16
Select Case i
Case 1, 2, 9, 16
m_LeftShifts(i) = 1
Case Else
m_LeftShifts(i) = 2
End Select
Next
'Initialize the eight s-boxes
vSbox(0) = Array(14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7, _
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8, _
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0, _
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13)
vSbox(1) = Array(15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, _
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5, _
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15, _
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9)
vSbox(2) = Array(10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8, _
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1, _
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7, _
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12)
vSbox(3) = Array(7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15, _
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9, _
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4, _
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14)
vSbox(4) = Array(2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9, _
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6, _
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14, _
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3)
vSbox(5) = Array(12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11, _
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8, _
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6, _
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13)
vSbox(6) = Array(4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1, _
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6, _
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2, _
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12)
vSbox(7) = Array(13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7, _
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2, _
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8, _
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11)
Dim lBox As Long
Dim lRow As Long
Dim lColumn As Long
Dim TheByte(0) As Byte
Dim TheBin(0 To 7) As Byte
Dim a As Byte, b As Byte, C As Byte, D As Byte, e As Byte, F As Byte
'Create an optimized version of the s-boxes
'this is not in the standard but much faster
'than calculating the Row/Column index later
For lBox = 0 To 7
For a = 0 To 1
For b = 0 To 1
For C = 0 To 1
For D = 0 To 1
For e = 0 To 1
For F = 0 To 1
lRow = a * 2 + F
lColumn = b * 8 + C * 4 + D * 2 + e
TheByte(0) = vSbox(lBox)(lRow * 16 + lColumn)
Call Byte2Bin(TheByte(), 1, TheBin())
Call CopyMem(m_sBox(lBox, a, b, C, D, e, F), TheBin(4), 4)
Next
Next
Next
Next
Next
Next
Next
End Sub