用vb实现DES加解密算法(二)--加密

用vb实现DES加解密算法(二)--加密(7)     C_D(i + 28) = D16(i)
Next

'PC_2转换,生成K16
For i = 0 To 47
    K16(i) = C_D(PC_2(i))
Next

'**************************************************************************************

'将明文位数扩展为8的倍数
If (UBound(sCode) + 1) Mod 8 > 0 Then ReDim Preserve sCode(((UBound(sCode) + 1) \ 8 + 1) * 8 - 1)
'定义返回密文长度
ReDim bReturn(UBound(sCode))

For j = 0 To UBound(sCode) Step 8
    '加密过程
    '依次取8位加密
    CopyMemory tempCode(0), sCode(j), 8
    For i = 0 To 7
        BinCode(i * 8 + 0) = (tempCode(i) And &H80) \ &H80
        BinCode(i * 8 + 1) = (tempCode(i) And &H40) \ &H40
        BinCode(i * 8 + 2) = (tempCode(i) And &H20) \ &H20
        BinCode(i * 8 + 3) = (tempCode(i) And &H10) \ &H10
        BinCode(i * 8 + 4) = (tempCode(i) And &H8) \ &H8
        BinCode(i * 8 + 5) = (tempCode(i) And &H4) \ &H4
        BinCode(i * 8 + 6) = (tempCode(i) And &H2) \ &H2
        BinCode(i * 8 + 7) = (tempCode(i) And &H1) \ &H1
    Next
   
    'IP置换
    For i = 0 To 63
        CodeIP(i) = BinCode(IP(i))
    Next
   
    '分段
    For i = 0 To 31
        L0(i) = CodeIP(i)
        R0(i) = CodeIP(i + 32)
    Next
   
    '进行第一次迭代
    For i = 0 To 47
        CodeE(i) = R0(E(i))                 '经过E变换扩充，由32位变为48位