打印本文 打印本文 关闭窗口 关闭窗口
用vb实现DES加解密算法(二)--加密
作者:武汉SEO闵涛  文章来源:敏韬网  点击数4117  更新时间:2009/4/23 18:59:36  文章录入:mintao  责任编辑:mintao
sp;      S(6) = S7(CodeS7(5) + CodeS7(0) * 2, CodeS7(4) + CodeS7(3) * 2 + CodeS7(2) * 4 + CodeS7(1) * 8)
        S(7) = S8(CodeS8(5) + CodeS8(0) * 2, CodeS8(4) + CodeS8(3) * 2 + CodeS8(2) * 4 + CodeS8(1) * 8)
   
    ''''S盒运算32位结果
    For i = 0 To 7
        RetS(i * 4 + 0) = (S(i) And &H8) \ &H8
        RetS(i * 4 + 1) = (S(i) And &H4) \ &H4
        RetS(i * 4 + 2) = (S(i) And &H2) \ &H2
        RetS(i * 4 + 3) = (S(i) And &H1) \ &H1
    Next
   
   
    For i = 0 To 31
        ''''P变换
        CodeP(i) = RetS(P(i))
       
        ''''产生L14,R14
        R14(i) = L13(i) Xor CodeP(i)
        L14(i) = R13(i)
    Next
   
   
    ''''进行第15次迭代
    For i = 0 To 47
        CodeE(i) = R14(E(i))                 ''''经过E变换扩充,由32位变为48位
        CodeE(i) = CodeE(i) Xor K15(i)        ''''与K15按位作不进位加法运算
    Next
   
    ''''分8组
    For i = 0 To 5
        CodeS1(i) = CodeE(i)
        CodeS2(i) = CodeE(i + 6)
        CodeS3(i) = CodeE(i + 12)
        CodeS4(i) = CodeE(i + 18)
        CodeS5(i) = CodeE(i + 24)
        CodeS6(i) = CodeE(i + 30)
        CodeS7(i) = CodeE(i + 36)
        CodeS8(i) = CodeE(i + 42)
    Next
   
    ''''S盒运算,得到8个数
   
        S(0) = S1(CodeS1(5) + CodeS1(0) * 2, CodeS1(4) + CodeS1(3) * 2 + CodeS1(2) * 4 + CodeS1(1) * 8)
        S(1) = S2(CodeS2(5) + CodeS2(0) * 2, CodeS2(4) + CodeS2(3) * 2 + CodeS2(2) * 4 + CodeS2(1) * 8)
        S(2) = S3(CodeS3(5) + CodeS3(0) * 2, CodeS3(4) + CodeS3(3) * 2 + CodeS3(2) * 4 + CodeS3(1) * 8)
        S(3) = S4(CodeS4(5) + CodeS4(0) * 2, CodeS4(4) + CodeS4(3) * 2 + CodeS4(2) * 4 + CodeS4(1) * 8)
        S(4) = S5(CodeS5(5) + CodeS5(0) * 2, CodeS5(4) + CodeS5(3) * 2 + CodeS5(2) * 4 + CodeS5(1) * 8)
        S(5) = S6(CodeS6(5) + CodeS6(0) * 2, CodeS6(4) + CodeS6(3) * 2 + CodeS6(2) * 4 + CodeS6(1) * 8)
        S(6) = S7(CodeS7(5) + CodeS7(0) * 2, CodeS7(4) + CodeS7(3) * 2 + CodeS7(2) * 4 + CodeS7(1) * 8)
        S(7) = S8(CodeS8(5) + CodeS8(0) * 2, CodeS8(4) + CodeS8(3) * 2 + CodeS8(2) * 4 + CodeS8(1) * 8)
   
    ''''S盒运算32位结果
    For i = 0 To 7
        RetS(i * 4 + 0) = (S(i) And &H8) \ &H8
        RetS(i * 4 + 1) = (S(i) And &H4) \ &H4
        RetS(i * 4 + 2) = (S(i) And &H2) \ &H2
        RetS(i * 4 + 3) = (S(i) And &H1) \ &H1
    Next
   
   
    For i = 0 To 31
        ''''P变换
        CodeP(i) = RetS(P(i))
       
        ''''产生L15,R15
        R15(i) = L14(i) Xor CodeP(i)
        L15(i) = R14(i)
    Next
   
    ''''进行第16次迭代
    For i = 0 To 47
        CodeE(i) = R15(E(i))                 ''''经过E变换扩充,由32位变为48位
        CodeE(i) = CodeE(i) Xor K16(i)        ''''与K16按位作不进位加法运算
    Next
   
    ''''分8组
    For i = 0 To 5
        CodeS1(i) = CodeE(i)
        CodeS2(i) = CodeE(i + 6)
        CodeS3(i) = CodeE(i + 12)
        CodeS4(i) = CodeE(i + 18)
        CodeS5(i) = CodeE(i + 24)
        CodeS6(i) = CodeE(i + 30)
        CodeS7(i) = CodeE(i + 36)
        CodeS8(i) = CodeE(i + 42)
    Next
   
    ''''S盒运算,得到8个数
   
        S(0) = S1(CodeS1(5) + CodeS1(0) * 2, CodeS1(4) + CodeS1(3) * 2 + CodeS1(2) * 4 + CodeS1(1) * 8)
        S(1) = S2(CodeS2(5) + CodeS2(0) * 2, CodeS2(4) + CodeS2(3) * 2 + CodeS2(2) * 4 + CodeS2(1) * 8)
        S(2) = S3(CodeS3(5) + CodeS3(0) * 2, CodeS3(4) + CodeS3(3) * 2 + CodeS3(2) * 4 + CodeS3(1) * 8)
        S(3) = S4(CodeS4(5) + CodeS4(0) * 2, CodeS4(4) + CodeS4(3) * 2 + CodeS4(2) * 4 + CodeS4(1) * 8)
        S(4) = S5(CodeS5(5) + CodeS5(0) * 2, CodeS5(4) + CodeS5(3) * 2 + CodeS5(2) * 4 + CodeS5(1) * 8)
        S(5) = S6(CodeS6(5) + CodeS6(0) * 2, CodeS6(4) + CodeS6(3) * 2 + CodeS6(2) * 4 + CodeS6(1) * 8)
        S(6) = S7(CodeS7(5) + CodeS7(0) * 2, CodeS7(4) + CodeS7(3) * 2 + CodeS7(2) * 4 + CodeS7(1) * 8)
        S(7) = S8(CodeS8(5) + CodeS8(0) * 2, CodeS8(4) + CodeS8(3) * 2 + CodeS8(2) * 4 + CodeS8(1) * 8)
   
    ''''S盒运算32位结果
    For i = 0 To 7
        RetS(i * 4 + 0) = (S(i) And &H8) \ &H8
        RetS(i * 4 + 1) = (S(i) And &H4) \ &H4
        RetS(i * 4 + 2) = (S(i) And &H2) \ &H2
        RetS(i * 4 + 3) = (S(i) And &H1) \ &H1
    Next
   
   
    For i = 0 To 31
        ''''P变换
        CodeP(i) = RetS(P(i))
       
        ''''产生L11,R11
        R16(i) = L15(i) Xor CodeP(i)
        L16(i) = R15(i)
    Next
   
    For i = 0 To 31
        BinCode(i) = L16(i)
        BinCode(i + 32) = R16(i)
    Next
   
    For i = 0 To 63
        CodeIP(i) = BinCode(IP_1(i))
    Next
   
    For i = 0 To 7
        tempReturn(i) = CodeIP(i * 8 + 0) * &H80
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 1) * &H40
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 2) * &H20
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 3) * &H10
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 4) * &H8
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 5) * &H4
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 6) * &H2
        tempReturn(i) = tempReturn(i) + CodeIP(i * 8 + 7) * &H1
    Next
   
    CopyMemory bReturn(j), tempReturn(0), 8
Next
End Sub
   

上一页  [1] [2] [3] [4] [5] [6] [7] 

打印本文 打印本文 关闭窗口 关闭窗口