我正在编写一个程序,以帮助我收集有关密码安全的研究报告的统计数据。我决定在尝试暴力破解MD5哈希密码时使应用程序运行在多个线程上,以获得明显的性能提升。该应用程序在单个线程上运行良好,但是一旦有2个线程运行,TryPass函数中的"using (MD5 md5Hash = MD5.Create())"就会抛出StackOverFlowException异常。
// Microsoft's GetMd5Hash function.
static string GetMd5Hash(MD5 md5Hash, string input)
{
// Convert the input string to a byte array and compute the hash.
byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
// Create a new Stringbuilder to collect the bytes
// and create a string.
StringBuilder sBuilder = new StringBuilder();
// Loop through each byte of the hashed data
// and format each one as a hexadecimal string.
for (int i = 0; i < data.Length; i++)
{
sBuilder.Append(data[i].ToString("x2"));
}
// Return the hexadecimal string.
return sBuilder.ToString();
}
static bool TryPass(string attempt, string password)
{
using (MD5 md5Hash = MD5.Create())
{
if (GetMd5Hash(md5Hash, attempt) == password)
return true;
else
return false;
}
}
static bool BruteForce(BruteOptions bruteOptions)
{
if (bruteOptions.prefix.Length == 1 && TryPass(bruteOptions.prefix, bruteOptions.password)) // If it's the first in a series, try it.
return true;
for (int i = 0; i < bruteOptions.chars.Length; i++)
{
if (TryPass(bruteOptions.prefix + bruteOptions.chars[i], bruteOptions.password))
{
Console.WriteLine("The password is: " + bruteOptions.prefix + bruteOptions.chars[i]);
return true;
}
if (bruteOptions.prefix.Length + 1 < bruteOptions.maxLength)
if (BruteForce(bruteOptions))
return true;
//Console.WriteLine(prefix + chars[i]);
}
return false;
}
public struct BruteOptions
{
public string password, prefix;
public char[] chars;
public int maxLength;
}
static void OptionBruteForce()
{
Console.WriteLine("-----------------------");
Console.WriteLine("----- Brute-Force -----");
Console.WriteLine("-----------------------");
BruteOptions bruteOptions = new BruteOptions();
bruteOptions.password = ReadString("Enter the MD5 password hash to brute-force: ");
bruteOptions.chars = ReadString("Enter the characters to use: ").ToCharArray();
bruteOptions.maxLength = ReadIntegerRange("Max length of password: ", 1, 16);
bruteOptions.prefix = "";
Stopwatch myStopWatch = Stopwatch.StartNew();
int NUM_THREADS = bruteOptions.chars.Length;
Thread[] workers = new Thread[NUM_THREADS]; // Run a thread for each char.
var countdownEvent = new CountdownEvent(NUM_THREADS);
bool result = false;
// Start workers.
for (int i = 0; i < NUM_THREADS; i++)
{
int index = i;
BruteOptions newBruteOptions = bruteOptions;
newBruteOptions.prefix = bruteOptions.chars[index].ToString();
workers[index] = new Thread(delegate()
{
// Also check single char.
if (BruteForce(bruteOptions))
{
result = true;
// End all other threads.
for (int ii = 0; ii < NUM_THREADS; ii++)
{
if (workers[ii].ThreadState == System.Threading.ThreadState.Running && index != ii) // Ensures we don't prematurely abort this thread.
{
workers[ii].Abort();
countdownEvent.Signal(); // Signal so we can zero it and continue on the UI thread.
}
}
}
// Signal the CountdownEvent.
countdownEvent.Signal();
});
workers[index].Start();
}
// Wait for workers.
countdownEvent.Wait();
if (!result)
Console.WriteLine("No Match.");
Console.WriteLine("Took " + myStopWatch.ElapsedMilliseconds + " Milliseconds");
}
这就是所有相关的代码了。非常希望能得到关于为什么会出现这种情况的见解!我完全被难住了。我尝试在初始化每个线程时指定更大的堆栈大小,但没有效果。
提前感谢!