C#DES加密不起作用如何调试 [英] C# DES encryption not working how to debug
本文介绍了C#DES加密不起作用如何调试的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我用C#编写了一个使用DES的加密应用程序.
我根据DES算法说明自行编写了加密方法，出于各种原因，我没有使用内置方法.
我检查了很多次，但仍然无法正常工作.经过加密和解密后，它不会返回原始文本.
我需要一些想法，如何在我的代码中找到并纠正问题！
我不知道经过部分加密或解密后应该获得什么样的位数组，因此无法在代码中找到逻辑缺陷.
作为最后的选择，我可以发布/发送代码，但是如果我自己发现问题(基于您的调试思想)，我会更加高兴！
更新:
我不想在内置方法中使用，因为我通过这种方式学到了很多东西，并且想知道我是否喜欢密码编程...
I wrote an encryption application in C# which uses DES.
I wrote the encryption methods myself based on the DES algorithm description, not using the in-built methods for various reasons.
I checked it many times but still it still not working properly. It doesn''t give back the original text after encryption and decryption.
I need ideas how can I find and correct the problem in my code!
I don''t know what kind of bit array should i get after parts of encryption or decryption, so I can''t locate the logical flaw in my code.
As last resort I could post/send my code, but I would be much happier if I could find the problem myself (based on your debugging ideas)!
UPDATE:
I don''t want to use in built methods because I learn much more this way, and wanted to know if I like cryptographic programing or not...
//Execute the first permutation
public bool[] initialPermuation(bool[] sixtyfourbits)
{
bool[] bits = new bool[64];
int[] perm = new int[64]
{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};
for (int i = 0; i < 64; i++)
{
bits[i] = sixtyfourbits[perm[i] - 1];
}
return bits;
}
/// <summary>
/// Execute the first permutations inverz
/// </summary>
/// <param name="sixtyfourbitsR"></param>
/// <returns></returns>
public bool[] initialPermuationREV(bool[] sixtyfourbitsR)
{
bool[] bits = new bool[64];
int[] perm = new int[64]
{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};
for (int i = 0; i < 64; i++)
{
bits[i] = sixtyfourbitsR[perm[i] - 1];
}
return bits;
}
/// <summary>
/// Execute a XOR operation
/// </summary>
/// <param name="one"></param>
/// <param name="two"></param>
/// <returns></returns>
private bool plusz(bool one, bool two)
{
bool end = false;
if (one || two) end = true;
if (one && two) end = false;
return end;
}
/// <summary>
/// Execute the XOR operation in two 32 bit array
/// </summary>
/// <param name="one"></param>
/// <param name="two"></param>
/// <returns></returns>
private bool[] plusz32(bool[] one, bool[] two)
{
for (int i = 0; i < 32; i++)
{
one[i] = plusz(one[i], two[i]);
}
return one;
}
/// <summary>
/// Execute the convertion from 32 bits to 48 bits
/// </summary>
/// <param name="alap"></param>
/// <returns></returns>
private bool[] E32bitTO48(bool[] alap)
{
bool[] kimeno = new bool[48];
int[] perm = new int[48]
{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};
for (int i = 0; i < 48; i++)
{
kimeno[i] = alap[perm[i] - 1];
}
return kimeno;
}
/// <summary>
/// Execute the permutation for the 32 bits
/// </summary>
/// <param name="alap"></param>
/// <returns></returns>
private bool[] permutation32bit(bool[] alap)
{
bool[] bits = new bool[32];
int[] perm = new int[32]
{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};
for (int i = 0; i < 32; i++)
{
bits[i] = alap[perm[i] - 1];
}
return bits;
}
/// <summary>
/// Executes a permutation and divides the base bits into two array
/// </summary>
/// <param name="alap"></param>
/// <param name="keyD"></param>
/// <returns></returns>
private bool[] permutation1Key(bool[] alap, out bool[] keyD)
{
keyD = new bool[28];
bool[] bits = new bool[28];
int[] perm = new int[28]
{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};
int[] perm2 = new int[28]
{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};
for (int i = 0; i < 28; i++)
{
bits[i] = alap[perm[i] - 1];
}
for (int i = 0; i < 28; i++)
{
keyD[i] = alap[perm2[i] - 1];
}
return bits;
}
/// <summary>
/// Adds two 28 bit array, then execute the 48 bits permutation
/// </summary>
/// <param name="alap1"></param>
/// <param name="alap2"></param>
/// <returns></returns>
private bool[] permutation2Key(bool[] alap1, bool[] alap2)
{
bool[] summ = new bool[56];
bool[] bits = new bool[48];
for (int i = 0; i < 28; i++)
{
summ[i] = alap1[i];
summ[28 + i] = alap2[i];
}
int[] perm = new int[48]
{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};
for (int i = 0; i < 48; i++)
{
bits[i] = summ[perm[i] - 1];
}
return bits;
}
/// <summary>
/// Left shift
/// </summary>
/// <param name="szam">How many times it executes</param>
/// <param name="alap"></param>
/// <returns></returns>
private bool[] leftShift(int szam, bool[] alap)
{
bool[] bits = new bool[alap.Length];
int z = shifts[szam - 1];
for (int j = 0; j < z; j++)
{
for (int i = 0; i < alap.Length; i++)
{
if (i != alap.Length - 1) bits[i] = alap[i + 1];
else bits[i] = alap[0];
}
}
return bits;
}
/// <summary>
/// Sets the column and row for the S algorithm
/// </summary>
/// <param name="alap"></param>
/// <param name="second">Column number</param>
/// <returns>Row number</returns>
private int sSelection(bool[] alap, out int second)
{
int ki = 0;
second = 0;
if (alap[0]) ki = ki + 2;
if (alap[5]) ki = ki + 1;
if (alap[1]) second = second + 8;
if (alap[2]) second = second + 4;
if (alap[3]) second = second + 2;
if (alap[4]) second = second + 1;
return ki;
}
/// <summary>
/// Converts the numbers got from one the S part of the encryption into bits
/// </summary>
/// <param name="xy"></param>
/// <returns></returns>
private bool[] sAddOut(int xy)
{
bool[] bits = new bool[4];
if (xy >= 8)
{
bits[0] = true;
xy = xy - 8;
}
else bits[0] = false;
if (xy >= 4)
{
bits[1] = true;
xy = xy - 4;
}
else bits[1] = false;
if (xy >= 2)
{
bits[2] = true;
xy = xy - 2;
}
else bits[2] = false;
if (xy >= 1)
{
bits[3] = true;
xy = xy - 1;
}
else bits[3] = false;
return bits;
}
/// <summary>
/// Creates the needed subkey
/// </summary>
/// <param name="KeyN">The parameter for which key is needed</param>
/// <returns>The key bits</returns>
private bool[] KeyGeneration(int KeyN)
{
if (txtkey.Text == "" || txtkey.Text.Length != 8) MessageBox.Show("Nem megfelelő kulcs!");
char[] kulcs = txtkey.Text.ToCharArray();
bool[] kulcsbits = chartoBool(kulcs);
bool[] Dn;
bool[] Cn = permutation1Key(kulcsbits, out Dn);
for (int i = 0; i < KeyN; i++)
{
Cn = leftShift(i + 1, Cn);
Dn = leftShift(i + 1, Dn);
}
bool[] bits = permutation2Key(Cn, Dn);
return bits;
}
/// <summary>
/// Executes one part of the encryption sequence
/// </summary>
/// <param name="alapX"></param>
/// <param name="KulcsN"></param>
/// <returns></returns>
private bool[] fScrpyt(bool[] alapX, bool[] KulcsN)
{
bool[] bits = new bool[48];
bits = E32bitTO48(alapX);
for (int i = 0; i < 48; i++)
{
bits[i] = plusz(bits[i], KulcsN[i]);
}
bool[][] bitA = new bool[8][];
bool[][] bitA2 = new bool[8][];
for (int i = 0; i < 8; i++)
{
bitA[i] = new bool[6];
for (int j = 0; j < 6; j++)
{
bitA[i][j] = bits[j + i * 6];
}
}
int Sx, Sy;
Sx = sSelection(bitA[0], out Sy);
bitA2[0] = sAddOut(S1[Sx, Sy]);
Sx = sSelection(bitA[1], out Sy);
bitA2[1] = sAddOut(S2[Sx, Sy]);
Sx = sSelection(bitA[2], out Sy);
bitA2[2] = sAddOut(S3[Sx, Sy]);
Sx = sSelection(bitA[3], out Sy);
bitA2[3] = sAddOut(S4[Sx, Sy]);
Sx = sSelection(bitA[4], out Sy);
bitA2[4] = sAddOut(S5[Sx, Sy]);
Sx = sSelection(bitA[5], out Sy);
bitA2[5] = sAddOut(S6[Sx, Sy]);
Sx = sSelection(bitA[6], out Sy);
bitA2[6] = sAddOut(S7[Sx, Sy]);
Sx = sSelection(bitA[7], out Sy);
bitA2[7] = sAddOut(S8[Sx, Sy]);
bool[] thirtytwo = new bool[32];
for (int i = 0; i < 8; i++)
{
for (int j = 0; j < 4; j++)
{
thirtytwo[i * 4 + j] = bitA2[i][j];
}
}
return permutation32bit(thirtytwo);
}
/// <summary>
/// Divides a 64 bit array into two 32 bit array
/// </summary>
/// <param name="alap"></param>
/// <param name="second"></param>
/// <returns></returns>
private bool[] seperate(bool[] alap, out bool[] second)
{
bool[] bits = new bool[32];
second = new bool[32];
for (int i = 0; i < 32; i++)
{
bits[i] = alap[i];
}
for (int i = 0; i < 32; i++)
{
second[i] = alap[32 + i];
}
return bits;
}
/// <summary>
/// Adds two 32 bit array into a 64 bit array
/// </summary>
/// <param name="one"></param>
/// <param name="two"></param>
/// <returns></returns>
private bool[] pluszbool64(bool[] one, bool[] two)
{
bool[] all = new bool[64];
for (int i = 0; i < 32; i++)
{
all[i] = one[i];
}
for (int i = 0; i < 32; i++)
{
all[32 + i] = two[i];
}
return all;
}
/// <summary>
/// Execute the encrypton algorithm
/// </summary>
/// <param name="textbits"></param>
/// <returns></returns>
private bool[] Encrpytion(bool[] textbits)
{
int hossz = textbits.Length / 64;
bool[] bits = new bool[64];
for (int i = 0; i < hossz; i++)
{
for (int j = 0; j < 64; j++)
{
bits[j] = textbits[j + i * 64];
}
bits = initialPermuation(bits);
bool[] left = new bool[32];
bool[] right = new bool[32];
bool[] leftN = new bool[32];
bool[] rightN = new bool[32];
left = seperate(bits, out right);
for (int ii = 0; ii < 16; ii++)
{
leftN = right;
rightN = plusz32(left, fScrpyt(right, KeyGeneration(ii + 1)));
left = leftN;
right = rightN;
}
bits = pluszbool64(right, left);
}
return initialPermuationREV(bits);
}
/// <summary>
/// Execute the decryptom algorithm
/// </summary>
/// <param name="textbits"></param>
/// <returns></returns>
private bool[] Decrpytion(bool[] textbits)
{
int hossz = textbits.Length / 64;
bool[] bits = new bool[64];
for (int i = 0; i < hossz; i++)
{
for (int j = 0; j < 64; j++)
{
bits[j] = textbits[j + i * 64];
}
bits = initialPermuationREV(bits);
bool[] left = new bool[32];
bool[] right = new bool[32];
bool[] leftN = new bool[32];
bool[] rightN = new bool[32];
left = seperate(bits, out right);
leftN = left;
left = right;
right = leftN;
for (int ii = 16; ii > 0; ii--)
{
rightN = left;
leftN = plusz32(right, fScrpyt(left, KeyGeneration(ii)));
left = leftN;
right = rightN;
}
bits = pluszbool64(right, left);
}
return initialPermuation(bits);
}
int[,] S1 = new int[4, 16] {
{ 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}};
int[,] S2 = new int[4, 16]
{{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
{2, 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}};
int[,] S3 = new int[4, 16]
{{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}};
int[,] S4 = new int[4, 16]
{{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}};
int[,] S5 = new int[4, 16]
{{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}};
int[,] S6 = new int[4, 16]
{{10, 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}};
int[,] S7 = new int[4, 16]
{{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}};
int[,] S8 = new int[4, 16]
{{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}};
int[] shifts = new int[16] { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };
推荐答案
We can''t help much at all.
We have no idea how you have implemented the algorithms, let alone how you have implemented the code that uses them - and they aren''t simple algorithms to implement in the first place!
I would start by implementing the same code, but using the built in DES encryption, and comparing the output. If there is something really obvious - like your files are a quarter the size - that that would at least give you a clue. If they are the same size, then start looking at the data - does it have any similarities at all? But then, when you have implemented it using the standard methods, does it matter why your version doesn''t work? Do you have the time to find out?
But to be honest, even with your code, I suspect that you are going to be on your own on this one - and without it, we can''t even make constructive suggestions.
Sorry.
We can''t help much at all.
We have no idea how you have implemented the algorithms, let alone how you have implemented the code that uses them - and they aren''t simple algorithms to implement in the first place!
I would start by implementing the same code, but using the built in DES encryption, and comparing the output. If there is something really obvious - like your files are a quarter the size - that that would at least give you a clue. If they are the same size, then start looking at the data - does it have any similarities at all? But then, when you have implemented it using the standard methods, does it matter why your version doesn''t work? Do you have the time to find out?
But to be honest, even with your code, I suspect that you are going to be on your own on this one - and without it, we can''t even make constructive suggestions.
Sorry.
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