public static int GenerateKey(string inputString, int keyNumber, int keyStretchingCount)
{
var md5 = System.Security.Cryptography.MD5.Create();
var threePattern = @"(.)\1\1";
var fivePattern = @"(.)\1\1\1\1";
var threeRgx = new Regex(threePattern);
var fiveRgx = new Regex(fivePattern);
var index = 0;
var foundKeys = new List <int>();
var triples = new Dictionary <int, string>();
while (foundKeys.Count < keyNumber || (foundKeys.Count > keyNumber - 1 && index < foundKeys[keyNumber - 1] + 1000))
{
var md5string = MD5.CalculateMd5(inputString + index.ToString(), md5);
for (var j = 0; j < keyStretchingCount; j++)
{
md5string = MD5.CalculateMd5(md5string.ToLower(), md5);
}
Match fiveMatch = fiveRgx.Match(md5string);
if (fiveMatch.Success)
{
foreach (var triple in triples)
{
if (triple.Key > index - 1000 &&
!foundKeys.Contains(triple.Key) &&
triple.Value == fiveMatch.Groups[0].Value.Substring(0, 3))
{
foundKeys.Add(triple.Key);
}
}
triples.Add(index, fiveMatch.Groups[0].Value.Substring(0, 3));
}
else
{
Match threeMatch = threeRgx.Match(md5string);
if (threeMatch.Success)
{
triples.Add(index, threeMatch.Groups[0].Value);
}
}
foundKeys.Sort();
index++;
}
return(foundKeys[keyNumber - 1]);
}
public string FindPassword(string doorId)
{
string password = "";
int index = 0;
string md5string = "";
while (password.Length < 8)
{
md5string = MD5.CalculateMd5(doorId + index.ToString(), md5);
if (md5string.Substring(0, 5) == "00000")
{
password += md5string.Substring(5, 1);
}
index++;
}
return(password);
}
public string FindSecondPassword(string doorId)
{
char[] password = new char[8];
int index = 0;
int found = 0;
string md5string = "";
while (found < 8)
{
md5string = MD5.CalculateMd5(doorId + index.ToString(), md5);
if (md5string.Substring(0, 5) == "00000")
{
try {
int pos = int.Parse(md5string.Substring(5, 1));
if (pos < 8 && password[pos] == '\0')
{
char passwordChar = md5string.Substring(6, 1)[0];
password[pos] = passwordChar;
found++;
}
} catch (FormatException) {
}
}
index++;
}
var retPassword = "";
foreach (var c in password)
{
retPassword += c;
}
return(retPassword);
}