using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Security.Cryptography;
using System.Text;
namespace License
{
static class LicenseKey
{
static void Main()
{
string key = GenerateKey("5D67D8FF", 81561930, 30);
Console.WriteLine(key);
}
static string GenerateKey(string secretPhase, int machineCode, int days, bool unlimited = false)
{
secretPhase = twentyfiveByteHash(ComputeMD5(secretPhase));
int value = Convert.ToInt32(DateTime.Today.ToString("yyMMdd"));
decimal d = 0m + value;
d *= 1000m;
d += days;
d *= 1000m;
bool[] _tfg = new bool[8];
_tfg[0] = unlimited;
d += booleanToInt(_tfg);
d *= 100000000m;
d += machineCode;
int hash = getEightByteHash(d.ToString());
string text = hash + encText(d.ToString(), secretPhase);
text = base10ToBase26(text);
string key = string.Concat(new string[] { text.Substring(0, 5), "-", text.Substring(5, 5), "-", text.Substring(10, 5), "-", text.Substring(15, 5) });
return key;
}
static string ComputeMD5(string text)
{
StringBuilder stringBuilder = new StringBuilder();
MD5 md = MD5.Create();
byte[] array = md.ComputeHash(Encoding.Unicode.GetBytes(text));
md.Clear();
for (int i = 0; i < array.Length; i++)
{
stringBuilder.Append(((int)(byte.MaxValue - array[i])).ToString("X2"));
}
return stringBuilder.ToString();
}
static string twentyfiveByteHash(string s)
{
int num = s.Length / 5;
string[] array = new string[num + 1];
if (s.Length <= 5)
{
array[0] = getEightByteHash(s).ToString();
}
else if (s.Length > 5)
{
for (int i = 0; i <= num - 2; i++)
{
array[i] = getEightByteHash(s.Substring(i * 5, 5)).ToString();
}
array[array.Length - 2] = getEightByteHash(s.Substring((array.Length - 2) * 5, s.Length - (array.Length - 2) * 5)).ToString();
}
return string.Join("", array);
}
static string decText(string _encryptedPhase, string _secretPhase)
{
string text = "";
for (int i = 0; i <= _encryptedPhase.Length - 1; i++)
{
text += modulo(Convert.ToInt32(_encryptedPhase.Substring(i, 1)) - Convert.ToInt32(_secretPhase.Substring(modulo(i, _secretPhase.Length), 1)), 10);
}
return text;
}
static string decrypt(string _key, string _secretPhase)
{
string result;
if (string.IsNullOrEmpty(_secretPhase) | _secretPhase == null)
{
result = base26ToBase10(_key);
}
else
{
string text = base26ToBase10(_key);
result = text.Substring(0, 8) + decText(text.Substring(8), _secretPhase);
}
return result;
}
static string base26ToBase10(string s)
{
string text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
BigInteger left = default(BigInteger);
for (int i = 0; i <= s.Length - 1; i++)
{
BigInteger right = powof(26, s.Length - i - 1);
left += text.IndexOf(s.Substring(i, 1)) * right;
}
return left.ToString();
}
static BigInteger powof(int x, int y)
{
BigInteger bigInteger = 1;
BigInteger result;
if (y == 0)
{
result = 1;
}
else if (y == 1)
{
result = x;
}
else
{
for (int i = 0; i <= y - 1; i++)
{
bigInteger *= x;
}
result = bigInteger;
}
return result;
}
static int booleanToInt(bool[] _booleanArray)
{
int num = 0;
for (int i = 0; i < _booleanArray.Length; i++)
{
bool flag = _booleanArray[i];
if (flag)
{
num += Convert.ToInt32(Math.Pow(2.0, (double)(_booleanArray.Length - i - 1)));
}
}
return num;
}
static int modulo(int _num, int _base)
{
return _num - _base * Convert.ToInt32(Math.Floor((double)_num / _base));
}
static string encText(string _inputPhase, string _secretPhase)
{
//_inputPhase.Dump();
string text = "";
for (int i = 0; i <= _inputPhase.Length - 1; i++)
{
text += modulo(Convert.ToInt32(_inputPhase.Substring(i, 1)) + Convert.ToInt32(_secretPhase.Substring(modulo(i, _secretPhase.Length), 1)), 10);
}
return text;
}
static string base10ToBase26(string s)
{
char[] array = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();
BigInteger num = BigInteger.Parse(s);
char[] array2 = new char[s.ToString().Length + 1];
int num2 = 0;
while (num >= 26)
{
int num3 = (int)(num % 26);
array2[num2] = array[num3];
num = (num - num3) / 26;
num2++;
}
array2[num2] = array[(int)(num)];
string text = "";
for (int i = num2; i >= 0; i--)
{
text += array2[i];
}
return text;
}
static string Return_Lenght(string Number, int Lenght)
{
if (Number.ToString().Length != Lenght)
{
while (Number.ToString().Length != Lenght)
{
Number = "0" + Number;
}
}
return Number;
}
static bool[] intToBoolean(int _num)
{
string text = Return_Lenght(Convert.ToInt32(Convert.ToString(_num, 2)).ToString(), 8);
bool[] array = new bool[8];
for (int i = 0; i <= 7; i++)
{
array[i] = ((text.ToString().Substring(i, 1) == "1") ? true : false);
}
return array;
}
static int getEightByteHash(string s, int MUST_BE_LESS_THAN = 100000000)
{
uint num = 0U;
foreach (byte b in Encoding.Unicode.GetBytes(s))
{
num += (uint)b;
num += num << 10;
num ^= num >> 6;
}
num += num << 3;
num ^= num >> 11;
num += num << 15;
int num2 = (int)((ulong)num % (ulong)((long)MUST_BE_LESS_THAN));
int num3 = MUST_BE_LESS_THAN / num2;
if (num3 > 1)
{
num2 *= num3;
}
return num2;
}
public static int getEightByteHash2(string s)
{
//This function generates a eight byte hash
//The length of the result might be changed to any length
//just set the amount of zeroes in MUST_BE_LESS_THAN
//to any length you want
uint hash = 0;
int MUST_BE_LESS_THAN = 100000000;//1000000;
foreach (byte b in System.Text.Encoding.Unicode.GetBytes(s))
{
hash += b;
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += (hash << 3);
hash ^= (hash >> 11);
hash += (hash << 15);
int result = (int)(hash % MUST_BE_LESS_THAN);
//we want the result to not be zero, as this would thrown an exception in check.
if (result == 0)
result = 1;
int check = MUST_BE_LESS_THAN / result;
if (check > 1)
{
result *= check;
}
//when result is less than MUST_BE_LESS_THAN, multiplication of result with check will be in that boundary.
//otherwise, we have to divide by 10.
if (MUST_BE_LESS_THAN == result)
result /= 10;
return result;
}
// Define other methods and classes here
}
}
Write, Run & Share C# code online using OneCompiler's C# online compiler for free. It's one of the robust, feature-rich online compilers for C# language, running on the latest version 8.0. Getting started with the OneCompiler's C# compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C# and start coding.
OneCompiler's C# online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
using System;
namespace Sample
{
class Test
{
public static void Main(string[] args)
{
string name;
name = Console.ReadLine();
Console.WriteLine("Hello {0} ", name);
}
}
}
C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.
You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.
| Data Type | Description | Range | size |
|---|---|---|---|
| int | To store integers | -2,147,483,648 to 2,147,483,647 | 4 bytes |
| double | to store large floating point numbers with decimals | can store 15 decimal digits | 8 bytes |
| float | to store floating point numbers with decimals | can store upto 7 decimal digits | 4 bytes |
| char | to store single characters | - | 2 bytes |
| string | to stores text | - | 2 bytes per character |
| bool | to stores either true or false | - | 1 bit |
datatype variable-name = value;
When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.
if(conditional-expression) {
// code
}
else {
// code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
// code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement) {
// code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.
data-type[] array-name;
Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.
static void method-name()
{
// code to be executed
}