C# implements DES encryption algorithm, and the .net class library encapsulates the corresponding classes for various encryption algorithms (symmetric and asymmetric). Data Encryption Standard (DES) is a symmetric encryption algorithm that allows senders and receivers to use the same key to encrypt and decrypt data.
DES was developed by IBM in 1975. It is considered an insecure algorithm due to its 56-bit key size and 64-bit block size. However, its successor, Triple DES (3DES), is secure. TripleDES applies the DES algorithm 3 times on each block. No, the author of jexus has completely implemented the DES encryption algorithm in C# a few days ago, and friends who need to copy it themselves.
Table Of Contents
C# implements DES encryption algorithm
The DES encryption call method and results are still shown in the figure above.
var text = "江湖人士(https://jhrs.com)是一个关注IT科技动态、技术经验分享、WordPress网站建设、wealthy affiliate 中文教程、国外最便宜域名、国外最便宜vps、网赚教程、国外网赚、网赚联盟、国外联盟营销、adsense 赚钱教程、养育小孩、游戏攻略、美女图片、热门美剧、以及分享赚被动收入的网站。";
var key = "key is:jhrs.com";
var des = new DES(Encoding.Default);
var desText = des.Encrypt(text, key);
Console.WriteLine("加密前的文本：{0}", text);
Console.WriteLine("*DES加密密钥：{0}", key);
Console.WriteLine("*DES加密结果：{0}", desText);
Console.WriteLine("解密后的文本：{0}", des.Decrypt(desText, key));
Console.WriteLine();
Console.WriteLine("press any key to exit");
Console.ReadKey(true);
C# implements DES encryption
C# implements the DES encryption algorithm call result:
加密前的文本：江湖人士(https://jhrs.com)是一个关注IT科技动态、技术经验分享、WordPress网站建设、wealthy affiliate 中文教 程、国外最便宜域名、国外最便宜vps、网赚教程、国外网赚、网赚联盟、国外联盟营销、adsense 赚钱教程、养育小孩、游戏攻略、美 女图片、热门美剧、以及分享赚被动收入的网站。
*DES加密密钥：key is:jhrs.com
*DES加密结果：EDDCABF2E481C3E9E750F4C14D3810452382970F876322217A8183642420184327531CA8A7A32A0AA3D3E5262C3D4DC5A3C163D0E388F7C999F50EBD2BC0DDFA64391E7025AEDE8DFD7239A7B5995A800DB3FE6C28DBC2536C110873F2AD8741815E8CBF102C21211296729CEFE1EA219871117B2E266880CFB4A2508919152D2BFBD73081BE7AE3DF9B72D3E9F2E75C5CADD8FA9A8DF3C38ACC62A614C1A2D2B1AD8B1CAD6D859A5CADD8FA9A8DF3C30C3E79477B8A76E6A64535896C4352C6E34E94597AFD200CB09148C83735A4B456EC5F185A3736D16CB79A3AF464B71337BAB7292AF88B68A9846A8970AEF29EEF6317A9C039D18653B3C42631D9AF321340E09B4C292643217C56D7328F7E463B77CFA2F2A30E5C4469AEB20A19181FDF1EC1476F710CF8084E9DCB51D42E67B6584B878DC9CC6300F795C8ECAB8D4139E274EF0797419BC39CF7BD0914764710463E9A6B91CACF9897A8E94E7F1618707E9E40FFCAECBF4272FD452BD4EAC48387A976D22671B7
解密后的文本：江湖人士(https://jhrs.com)是一个关注IT科技动态、技术经验分享、WordPress网站建设、wealthy affiliate 中文教 程、国外最便宜域名、国外最便宜vps、网赚教程、国外网赚、网赚联盟、国外联盟营销、adsense 赚钱教程、养育小孩、游戏攻略、美 女图片、热门美剧、以及分享赚被动收入的网站。press any key to exit
C# implements DES encryption
C# DES Encryption Source Code
C# implements DES encryption source code:
/********************************************
* C# implementation of DES encryption and decryption
* ---------------------------------------
* Author: Yunei Liuyun (j66x@163.com), 2022.6.22
* Special Note: Please do not modify the author's signature, be a person who values trust and righteousness!
*****************************************/
namespace System.Text
{
using System.Runtime.CompilerServices;
/// <summary>
/// DES encryption and decryption class
/// </summary>
public sealed class DES
{
#region <definition>
#region <enum definition>
enum DES_TYPE
{
/// <summary>
/// encryption
/// </summary>
ENCRYPT,
/// <summary>
/// decrypt
/// </summary>
DECRYPT
};
#endregion
#region <table definition>
static readonly byte[] ip_table = new byte[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
};
readonly static byte[] ipr_table = new byte[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
};
readonly static byte[] e_table = new byte[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
};
readonly static byte[] p_table = new byte[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
};
readonly static byte[] pc1_table = new byte[56]{
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
};
readonly static byte[] pc2_table = new byte[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
};
readonly static byte[] loop_table = new byte[16] {
1, 1, 2, 2, 2, 2, 2, 2,
1, 2, 2, 2, 2, 2, 2, 1
};
readonly static byte[,,] s_box = new byte[8, 4, 16] {
//s1
{
{ 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 }
},
//s2
{
{ 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 }
},
//s3
{
{ 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 }
},
//s4
{
{ 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 }
},
//s5
{
{ 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 }
},
//s6
{
{ 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 }
},
//s7
{
{ 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 }
},
//s8
{
{ 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 }
}
};
#endregion
#region <Variable/Constant Definition>
/// <summary>
/// default key
/// </summary>
const string KEY_DEFAULT = "YUNEI.LIUYUN";
/// <summary>
/// original character set
/// </summary>
private readonly Encoding _encoding = Encoding.Default;
#endregion
#endregion
#region <internal method>
/// <summary>
/// Encryption/decryption (input/output buffers are both 8 bytes)
/// </summary>
/// <param name="lp_out">output</param>
/// <param name="lp_in">enter</param>
/// <param name="type"></param>
/// <param name="subkey"></param>
/// <param name=""></param>
static unsafe void DesRun(byte* lp_out, byte* lp_in, DES_TYPE type, byte* subkey)
{
var m = stackalloc byte[64];
var tmp = stackalloc byte[32];
var li = m + 0;
var ri = m + 32;
ByteToBit(m, lp_in, 64);
Transform(m, m, ip_table, 64);
if (type == DES_TYPE.ENCRYPT)
{
for (int i = 0; i < 16; i++)
{
MemCopy(tmp, ri, 32);
FuncF(ri, subkey + (i * 48));
XOR(ri, li, 32);
MemCopy(li, tmp, 32);
}
}
else
{
for (int i = 15; i >= 0; i--)
{
MemCopy(tmp, li, 32);
FuncF(li, subkey + (i * 48));
XOR(li, ri, 32);
MemCopy(ri, tmp, 32);
}
}
Transform(m, m, ipr_table, 64);
BitToByte(lp_out, m, 64);
}
/// <summary>
/// set subkey
/// </summary>
/// <param name="key"></param>
/// <param name="subkey_out"></param>
static unsafe void DesSetKey(string key, byte* subkey_out)
{
if (string.IsNullOrEmpty(key)) key = KEY_DEFAULT;
var des_key = stackalloc byte[8] { 0, 0, 0, 0, 0, 0, 0, 0 };
for (int ii = 0; ii < key.Length; ii++)
{ des_key[ii % 8] = (byte)((des_key[ii % 8] + key[ii]) % 256); }
var k = stackalloc byte[64];
var kl = k + 0;
var kr = k + 28;
ByteToBit(k, des_key, 64);
Transform(k, k, pc1_table, 56);
for (int i = 0; i < 16; i++)
{
Rotatel(kl, 28, loop_table[i]);
Rotatel(kr, 28, loop_table[i]);
Transform(subkey_out + (i * 48), k, pc2_table, 48);
}
}
static unsafe void FuncF(byte* lpin, byte* lpki)
{
var mr = stackalloc byte[48];
Transform(mr, lpin, e_table, 48);
XOR(mr, lpki, 48);
FuncS(lpin, mr);
Transform(lpin, lpin, p_table, 32);
}
static unsafe void FuncS(byte* lp_out, byte* lp_in)
{
for (int i = 0, j = 0, k = 0; i < 8; i++, lp_in += 6, lp_out += 4)
{
j = (lp_in[0] << 1) + lp_in[5];
k = (lp_in[1] << 3) + (lp_in[2] << 2) + (lp_in[3] << 1) + lp_in[4];
//bytetobit(lp_out, &s_box[i, j, k], 4);
fixed (byte* p = s_box)//s_box[8,4,16]
{
var pp = p + (i * 4 * 16) + (j * 16) + k;
ByteToBit(lp_out, pp, 4);
}
}
}
static unsafe void Transform(byte* out_bit, byte* in_bit, byte[] table, int len)
{
var tmp = stackalloc byte[256];
for (var i = 0; i < len; i++)
{
tmp[i] = in_bit[table “” not found /]<br>
- 1];
}
MemCopy(out_bit, tmp, len);
}
unsafe static void Rotatel(byte* lpin, int len, int loop)
{
var tmp = stackalloc byte[256];
MemCopy(tmp, lpin, loop);
MemCopy(lpin, lpin + loop, len - loop);
MemCopy(lpin + len - loop, tmp, loop);
}
#region <helper function>
/// <summary>
/// convert bytes to bits
/// </summary>
/// <param name="bit_out"></param>
/// <param name="byt_in"></param>
/// <param name="bits">The length of the output (bit length)</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
unsafe static void ByteToBit(byte* bit_out, byte* byt_in, int bits)
{
for (int i = 0; i < bits; i++)
{ bit_out[i] = (byte)((byt_in[i / 8] >> (i % 8)) & 0x01); }
}
/// <summary>
/// convert bits to bytes
/// </summary>
/// <param name="lp_out"></param>
/// <param name="lp_in"></param>
/// <param name="bits">bit length</param>
unsafe static void BitToByte(byte* lp_out, byte* lp_in, int bits)
{
MemZero(lp_out, (bits + 7) / 8);
for (int i = 0; i < bits; i++)
{ lp_out[i / 8] |= (byte)((lp_in[i] & 0x01) << (i % 8)); }
}
[method: MethodImpl(MethodImplOptions.AggressiveInlining)]
static unsafe void XOR(byte* ina, byte* inb, int len)
{
for (int i = 0; i < len; i++)
{ ina[i] ^= (byte)(inb[i] & 0x01); }
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
unsafe static void MemCopy(byte* dest, byte* src, int len)
{
for (int i = 0; i < len; i++) dest[i] = src[i];
}
/// <summary>
/// fill the specified buffer with 0
/// </summary>
/// <param name="buffer">buffer</param>
/// <param name="len">padding length</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
unsafe static void MemZero(byte* buffer, int len)
{
for (var i = 0; i < len; i++) buffer[i] = 0;
}
#endregion
#endregion
#region <Constructor>
/// <summary>
/// An example of using the system default character set as the encoding character set
/// </summary>
public DES() : this(Encoding.Default) { }
/// <summary>
/// An instance that uses the specified character set as the codec character set
/// </summary>
/// <param name="encoding"></param>
public DES(Encoding encoding)
{
_encoding = encoding;
}
#endregion
#region <public method or property>
/// <summary>
/// encryption
/// </summary>
/// <param name="text">original text to be encrypted</param>
/// <param name="key">key</param>
/// <returns>DES encrypted text</returns>
public unsafe string Encrypt(string text, string key = "")
{
if (string.IsNullOrEmpty(text)) return text;
var str_in = stackalloc byte[8];
var str_out = stackalloc byte[8];
var subkey = stackalloc byte[16 * 48]; //subkey
DesSetKey(key, subkey);
var byt_text = _encoding.GetBytes(text);
int text_len = byt_text.Length;
var byt_result = new byte[(text_len + 7) / 8 * 16];
int count = (text_len + 7) / 8;
for (int kk = 0; kk < count; kk++)
{
for (int ii = 0; ii < 8; ii++)
{
if (kk * 8 + ii < text_len) str_in[ii] = byt_text[kk * 8 + ii];
else str_in[ii] = 0;
}
DesRun(str_out, str_in, DES_TYPE.ENCRYPT, subkey);
for (int ii = 0; ii < 8; ii++)
{
var value = str_out[ii];
byt_result[kk * 16 + 2 * ii] = (byte)(value / 16 < 10 ? value / 16 + '0' : value / 16 - 10 + 'A');
byt_result[kk * 16 + 2 * ii + 1] = (byte)(value % 16 < 10 ? value % 16 + '0' : value % 16 - 10 + 'A');
}
}
return Encoding.ASCII.GetString(byt_result);
}
/// <summary>
/// decrypt
/// </summary>
/// <param name="des">DES encrypted text</param>
/// <param name="key">key</param>
/// <returns>Decrypted original text</returns>
public unsafe string Decrypt(string des, string key = "")
{
if (string.IsNullOrEmpty(des)) return des;
var byt_text = Encoding.ASCII.GetBytes(des);
//Convert the hexadecimal text string to normal characters.
int text_len = byt_text.Length;
var text_str = new byte[text_len / 2];
if (text_len % 16 != 0) return ""; //The length of the DES encrypted string must be a multiple of 16
for (int ii = 0; ii < text_len; ii += 2)
{
var ch1 = byt_text[ii];
var ch2 = byt_text[ii + 1];
if (!(ch1 >= '0' && ch1 <= '9' || ch1 >= 'A' && ch1 <= 'F')) return "";
if (!(ch2 >= '0' && ch2 <= '9' || ch2 >= 'A' && ch2 <= 'F')) return "";
var k1 = ch1 <= '9' ? ch1 - '0' : ch1 - 'A' + 10;
var k2 = ch2 <= '9' ? ch2 - '0' : ch2 - 'A' + 10;
var kk = (byte)(k1 * 16 + k2);
text_str[ii / 2] = kk;
}
var str_in = stackalloc byte[8];
var str_out = stackalloc byte[8];
var subkey = stackalloc byte[16 * 48];
DesSetKey(key, subkey);
text_len = text_str.Length;
var byt_result = new byte[text_len];
int len = 0;
for (int kk = 0; kk < text_len / 8; kk++)
{
for (int ii = 0; ii < 8; ii++)
{
if (kk * 8 + ii < text_len)
str_in[ii] = text_str[kk * 8 + ii];
else
str_in[ii] = 0;
}
DesRun(str_out, str_in, DES_TYPE.DECRYPT, subkey);
for (int ii = 0; ii < 8; ii++)
{
byt_result[kk * 8 + ii] = str_out[ii];
if (str_out[ii] != 0) len = kk * 8 + ii + 1;
}
}
return _encoding.GetString(byt_result, 0, len);
}
/// <summary>
/// The character set used by the current instance during encoding and decoding
/// </summary>
public Encoding Encoding { get { return _encoding; } }
#endregion
}
}
C# implements DES encryption
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