Develop Reference

C# RNGCryptoServiceProvider and special characters

I'm looking for a way to get random characters.I need a string must be contain at 2 least uppercase letters, at least 1 number and special characters.
Here is my code:
public static string CreateRandomPassword(int Length)
{
string _Chars = "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ[_!23456790";
Byte[] randomBytes = new Byte[Length];
var rng = new RNGCryptoServiceProvider();
rng.GetBytes(randomBytes);
var chars = new char[Length];
int Count = _Chars.Length;
for(int i = 0;i<Length;i++)
{
chars[i] = _Chars[(int)randomBytes[i] % Count];
}
return new string(chars);
}
some results:
ZNQzvUPFKOL3x
BQSEkKHXACGO
They haven't special characters and numbers.

your code works great! I've just wrapped it with a function that validate your conditions.
I've executed the following:
public static string CreateRandomPassword(int Length)
{
string _Chars = "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ[_!23456790";
Byte[] randomBytes = new Byte[Length];
var rng = new RNGCryptoServiceProvider();
rng.GetBytes(randomBytes);
var chars = new char[Length];
int Count = _Chars.Length;
for (int i = 0; i < Length; i++)
{
chars[i] = _Chars[(int)randomBytes[i] % Count];
}
return new string(chars);
}
public static string CreateRandomPasswordWith2UpperAnd1NumberAnd1Special(int length)
{
while (true)
{
var pass = CreateRandomPassword(length);
int upper=0, num =0, special = 0,lower=0;
foreach (var c in pass)
{
if (c > 'A' && c < 'Z')
{
upper++;
}
else if (c > 'a' && c < 'z')
{
lower++;
}
else if (c > '0' && c < '9')
{
num++;
}
else
{
special++;
}
}
if (upper>=2&&num>=1&&1>=special)
{
return pass;
}
}
}
[Test]
public void CreateRandomPassword_Length13_RandomPasswordWithNumbers()
{
var random = CreateRandomPasswordWith2UpperAnd1NumberAnd1Special(13);
Assert.IsTrue(true);
}

How to add chars numerically in c#

So I'm building a program that takes a string and turns it into a binary number (I.E. "A" = 01000001). Then, if the user wishes, it can that binary number convert it back into a ascii character. Here the code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading.Tasks;
namespace NDR_011
{
class Program
{
public static Byte[] BinStr(String binary)
{
var list = new List<Byte>();
for (int i = 0; i < binary.Length; i += 8)
{
String t = binary.Substring(i, 8);
list.Add(Convert.ToByte(t, 2));
}
return list.ToArray();
}
public static void Print(object mess)
{
string tmp = mess.ToString().ToUpper();
Console.Write(tmp);
}
private static List<string> buffer = new List<string>();
private static string outfile = "C:/tmp/bytes.bin";
static void Main(string[] args)
{
string tmp = "";
Print("NDR 011\n");
while (true)
{
Print(""); tmp = Console.ReadKey().Key.ToString().ToUpper();
if (Console.CursorLeft > 0)
{
Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
}
if (tmp == ConsoleKey.F1.ToString())
{
break;
} else if (tmp == ConsoleKey.F2.ToString())
{
comp();
continue;
} else if (tmp == ConsoleKey.F4.ToString())
{
buffer.Clear();
continue;
} else if (tmp == ConsoleKey.F5.ToString())
{
Print("N "); string a = Console.ReadLine();
outfile = a;
continue;
} else if (tmp == ConsoleKey.F5.ToString())
{
outfile = "C:/tmp/bytes.bin";
Print("Out file reset\n");
continue;
} else if (tmp == ConsoleKey.F7.ToString())
{
//Print("N "); // string a = Console.ReadLine();
string a = "C:/tmp/bytes.bin";
string[] s = File.ReadAllText(a).Split(' ');
char[] end = new char[s.Length - 1];
for (int i=0;i<end.Length;i++)
{
end[i] = (char)BinStr(s[i])[0];
//Print(end[i]);
}
//Print((char)BinStr(s[0])[0]);
if (end[0] == 'A' && end[1] == 'D' && end[2] == 'D')
{
for (int i=0+3;i<end.Length;i++)
{
int n = end[i] + end[i];
Print(n);
}
}
//decompile(a);
continue;
}
while (tmp.Length > 1)
{
char a = tmp[tmp.Length - 1];
tmp = a.ToString();
}
buffer.Add(tmp);
}
}
static void comp()
{
if (buffer == null || buffer.Count <= 0)
{
Print("Error buffer empty");
return;
}
char[] r = new char[buffer.Count];
for (int i=0;i<buffer.Count;i++)
{
r[i] = Convert.ToChar(buffer[i]);
Print(r[i]);
}
foreach (char ch in r)
{
string a = Convert.ToString((int)ch, 2);
while (a.Length != 8)
{
string b = "0";
a = b + a;
}
File.AppendAllText(outfile, a + " ");
}
Print("Compile done!\n");
}
static void decompile(string filename)
{
}
static void run()
{
}
}
}
(the indenation got messed up when I add to this post.)
The problem is this: when I try to add the values I get from the file I get random numbers like: 100102, and odd stuff like that. What am I doing wrong? Thanks

Here's how you convert a string to a binary string of 1s and 0s:
var binstring = string.Join(" ", Encoding.ASCII.GetBytes(("Welcome, World!")).Select(byt => Convert.ToString(byt, 2).PadLeft(8, '0')));
To convert that back into a string, we will need to a parse byte[] array from it with a method like so:
public static byte[] GetBytes(string s)
{
byte[] result = new byte[(s.Length + 7) / 8];
int i = 0;
int j = 0;
foreach (char c in s)
{
result[i] <<= 1;
if (c == '1')
result[i] |= 1;
j++;
if (j == 8)
{
i++;
j = 0;
}
}
return result;
}
Then we get those bytes and we can simply convert it into a string using:
Encoding.ASCII.GetString(GetBytes(binstring));
References: How could I encode a string of 1s and 0s for transport?How to get the binary code behind ASCII (C#)

Decrypt Function Equivalent in C#

I have this function to decrypt connection strings in VB .NET, and I try to bring it to C#:
Function DecryptText(strText As String, ByVal strPwd As String)
Dim i As Integer, c As Integer
Dim strBuff As String
#If Not CASE_SENSITIVE_PASSWORD Then
'Convert password to upper case
'if not case-sensitive
strPwd = UCase$(strPwd)
#End If
'Decrypt string
If Len(strPwd) Then
For i = 1 To Len(strText)
c = Asc(Mid$(strText, i, 1))
c = c - Asc(Mid$(strPwd, (i Mod Len(strPwd)) + 1, 1))
strBuff = strBuff & Chr$(c & &HFF)
Next i
Else
strBuff = strText
End If
DecryptText = strBuff
End Function
I tried with these two ways:
public static string DesencriptarCadena(this string cadena, string llave = "asdf")
{
try
{
cadena = cadena.Replace("\r", "").Replace("\n", "");
byte b = 0;
string strBuff = "";
System.Text.Encoding encoding = System.Text.Encoding.Default;
for (int i = 0; i < cadena.Length; i++)
{
b = encoding.GetBytes(cadena.ToCharArray(), i, 1)[0];
int ind = i % llave.Length;
b -= encoding.GetBytes(llave.ToCharArray(), ind, 1)[0];
strBuff += encoding.GetChars(new byte[] { Convert.ToByte((int)b & +0xff) })[0];
}
return strBuff;
}
catch (Exception ex)
{
return cadena;
}
}
or this other way:
public static string DesencriptarCadena(this string cadena, string llave = "asdf")
{
try
{
cadena = cadena.Replace("\r", "").Replace("\n", "");
int c;
string strBuff = "";
System.Text.Encoding encoding = System.Text.Encoding.Default;
for (int i = 0; i < cadena.Length; i++)
{
int ind = i % llave.Length;
c = cadena[i];
c -= llave[ind];
strBuff += Convert.ToChar(c & +0xff);
}
return strBuff;
}
catch (Exception ex)
{
return cadena;
}
}
But, it doesn't work. Can someone explain to me what I should do?
In the first way return:
ÞÓÚÏË×ÞÓÚÏË×ÞÓÚÏ ÞÓÚÏË×ÞÓÚÏú×ÞÓÚÏË×ÞÓÚÏË×ÞÓÚÏË×ÞÚÏË×ÞÓÚÏË×Þ
In the second: NúÎCÄÁÎî
It is not returning the decrypted connection string.

http://converter.telerik.com has always done great by me for these types of conversions. Let me know how this works.
public object DecryptText(string strText, string strPwd)
{
int i = 0;
int c = 0;
string strBuff = null;
#if Not CASE_SENSITIVE_PASSWORD
//Convert password to upper case
//if not case-sensitive
strPwd = Strings.UCase(strPwd);
#endif
//Decrypt string
if (Strings.Len(strPwd)) {
for (i = 1; i <= Strings.Len(strText); i++) {
c = Strings.Asc(Strings.Mid(strText, i, 1));
c = c - Strings.Asc(Strings.Mid(strPwd, (i % Strings.Len(strPwd)) + 1, 1));
strBuff = strBuff + Strings.Chr(c + 0xff);
}
} else {
strBuff = strText;
}
return strBuff;
}

After including the Microsoft.VisualBasic assembly, I added two using statements:
using Microsoft.VisualBasic;
using Microsoft.VisualBasic.CompilerServices;
I compiled it and decompiled it with dotPeek. It resulted in this:
public static object DecryptText(string strText, string strPwd)
{
string str = string.Empty;
strPwd = Strings.UCase(strPwd);
if ((uint)Strings.Len(strPwd) > 0U)
{
int num1 = 1;
int num2 = Strings.Len(strText);
int Start = num1;
while (Start <= num2)
{
int num3 = checked(Strings.Asc(Strings.Mid(strText, Start, 1)) - Strings.Asc(Strings.Mid(strPwd, unchecked(Start % Strings.Len(strPwd)) + 1, 1)));
str = str + Conversions.ToString(Convert.ToChar(Conversions.ToString(num3) + Conversions.ToString((int)byte.MaxValue)));
checked { ++Start; }
}
}
else
str = strText;
return (object)str;
}

convert UTF-8 HEX into emoji representation

How do we convert UTF-8 HEX: EE 94 93 into equivalent Emoji representation: 1f1e8, 1f1f3
taken from here: http://www.iemoji.com/view/emoji/175/places/regional-indicator-symbol-letters-cn

public static string ConvertEmoji2UnicodeHex(string emoji)
{
if (string.IsNullOrWhiteSpace(emoji))
return emoji;
byte[] bytes = Encoding.UTF8.GetBytes(emoji);
string firstItem = Convert.ToString(bytes[0], 2);
int iv;
if (bytes.Length == 1)
{
iv = Convert.ToInt32(firstItem, 2);
}
else
{
StringBuilder sbBinary = new StringBuilder();
sbBinary.Append(firstItem.Substring(bytes.Length + 1).TrimStart('0'));
for (int i = 1; i < bytes.Length; i++)
{
string item = Convert.ToString(bytes[i], 2);
item = item.Substring(2);
sbBinary.Append(item);
}
iv = Convert.ToInt32(sbBinary.ToString(), 2);
}
return Convert.ToString(iv, 16).PadLeft(4, '0');
}

AES to return Alphanumeric

I have an aes encryption code, i want to make it only return alphanumerical characters like {0123456789ABCDEFGHIJKLMNOPQRSTWUVYZ}
But however i could not figure out how to do that. I have almost no idea about encryption, could not figure out where to fix. I would really apreciate your feedback. Regards...
public class clsCrypto
{
private string _KEY = string.Empty;
protected internal string KEY
{
get
{
return _KEY;
}
set
{
if (!string.IsNullOrEmpty(value))
{
_KEY = value;
}
}
}
private string _IV = string.Empty;
protected internal string IV
{
get
{
return _IV;
}
set
{
if (!string.IsNullOrEmpty(value))
{
_IV = value;
}
}
}
private string CalcMD5(string strInput)
{
string strOutput = string.Empty;
if (!string.IsNullOrEmpty(strInput))
{
try
{
StringBuilder strHex = new StringBuilder();
using (MD5 md5 = MD5.Create())
{
byte[] bytArText = Encoding.Default.GetBytes(strInput);
byte[] bytArHash = md5.ComputeHash(bytArText);
for (int i = 0; i < bytArHash.Length; i++)
{
strHex.Append(bytArHash[i].ToString("X2"));
}
strOutput = strHex.ToString();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
return strOutput;
}
private byte[] GetBytesFromHexString(string strInput)
{
byte[] bytArOutput = new byte[] { };
if ((!string.IsNullOrEmpty(strInput)) && strInput.Length % 2 == 0)
{
SoapHexBinary hexBinary = null;
try
{
hexBinary = SoapHexBinary.Parse(strInput);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
bytArOutput = hexBinary.Value;
}
return bytArOutput;
}
private byte[] GenerateIV()
{
byte[] bytArOutput = new byte[] { };
try
{
string strIV = CalcMD5(IV);
bytArOutput = GetBytesFromHexString(strIV);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
return bytArOutput;
}
private byte[] GenerateKey()
{
byte[] bytArOutput = new byte[] { };
try
{
string strKey = CalcMD5(KEY);
bytArOutput = GetBytesFromHexString(strKey);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
return bytArOutput;
}
protected internal string Encrypt(string strInput, CipherMode cipherMode)
{
string strOutput = string.Empty;
if (!string.IsNullOrEmpty(strInput))
{
try
{
byte[] bytePlainText = Encoding.Default.GetBytes(strInput);
using (RijndaelManaged rijManaged = new RijndaelManaged())
{
rijManaged.Mode = cipherMode;
rijManaged.BlockSize = 128;
rijManaged.KeySize = 128;
rijManaged.IV = GenerateIV();
rijManaged.Key = GenerateKey();
rijManaged.Padding = PaddingMode.Zeros;
ICryptoTransform icpoTransform = rijManaged.CreateEncryptor(rijManaged.Key, rijManaged.IV);
using (MemoryStream memStream = new MemoryStream())
{
using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Write))
{
cpoStream.Write(bytePlainText, 0, bytePlainText.Length);
cpoStream.FlushFinalBlock();
}
strOutput = Encoding.Default.GetString(memStream.ToArray());
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
return strOutput;
}
protected internal string Decrypt(string strInput, CipherMode cipherMode)
{
string strOutput = string.Empty;
if (!string.IsNullOrEmpty(strInput))
{
try
{
byte[] byteCipherText = Encoding.Default.GetBytes(strInput);
byte[] byteBuffer = new byte[strInput.Length];
using (RijndaelManaged rijManaged = new RijndaelManaged())
{
rijManaged.Mode = cipherMode;
rijManaged.BlockSize = 128;
rijManaged.KeySize = 128;
rijManaged.IV = GenerateIV();
rijManaged.Key = GenerateKey();
rijManaged.Padding = PaddingMode.Zeros;
ICryptoTransform icpoTransform = rijManaged.CreateDecryptor(rijManaged.Key, rijManaged.IV);
using (MemoryStream memStream = new MemoryStream(byteCipherText))
{
using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Read))
{
cpoStream.Read(byteBuffer, 0, byteBuffer.Length);
}
strOutput = Encoding.Default.GetString(byteBuffer);
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
return strOutput;
}
}

Encryption and decryption functions use byte arrays as parameters.
So, you must convert these arrays to base 36 string.
You can use the following class (Base36) to make these conversions:
All you have to do, is calling these two functions:
byte[] byteArray;
//To convert byte array to String
string byteArrayInBase36 = Base36.ByteArrayToBase36String(byteArray);
//To convert String to byte Array
byte[] byteArray2 = Base36.Base36StringToByteArray(byteArrayInBase36);
and, this is the class:
using System;
using System.Collections.Generic;
class Base36
{
#region public methods
public static string ByteArrayToBase36String(byte[] bytes)
{
string result = string.Empty;
result = Encode36((ulong)bytes.Length).PadLeft(BASE36_LENGTH_BLOC_SIZE_36, '0');
if (bytes.Length > 0)
{
List<byte[]> byteslist = SplitBytes(bytes, 8);
if (byteslist[byteslist.Count - 1].Length < 8)
{
byte[] newLastArray = new byte[8];
byteslist[byteslist.Count - 1].CopyTo(newLastArray, 0);
byteslist[byteslist.Count - 1] = newLastArray;
}
foreach (byte[] byteArray in byteslist)
{
ulong value = 0;
//for (int i = 0; i < byteArray.Length; i++) value = value * 256 + byteArray[i];
value = BitConverter.ToUInt64(byteArray, 0);
result = result + Encode36(value).PadLeft(BASE36_BLOC_SIZE_36, '0');
}
}
return result;
}
public static byte[] Base36StringToByteArray(string input)
{
byte[] result = new byte[0];
if (input.Length >= BASE36_LENGTH_BLOC_SIZE_36)
{
int arrayLength = (int)Decode36(input.Substring(0, BASE36_LENGTH_BLOC_SIZE_36));
string data = input.Remove(0, BASE36_LENGTH_BLOC_SIZE_36);
List<byte[]> bytesList = new List<byte[]>();
foreach (string value36 in new List<string>(SplitStringByLength(data, BASE36_BLOC_SIZE_36)))
{
byte[] byteArray = BitConverter.GetBytes(Decode36(value36));
bytesList.Add(byteArray);
}
result = JoinBytes(bytesList);
Array.Resize(ref result, arrayLength);
}
return result;
}
#endregion
#region Const
private const int BASE36_LENGTH_BLOC_SIZE_36 = 6;
private const int BASE36_BLOC_SIZE_36 = 13; //Encode36(ulong.MaxValue).Length;
#endregion
#region private methods
static string _CharList36 = string.Empty;
static private string CharList36
{
get
{
if (_CharList36.Length < 36)
{
char[] array = new char[36];
for (int i = 0; i < 10; i++) array[i] = (char)(i + 48);
for (int i = 0; i < 26; i++) array[i + 10] = (char)(i + 97);
_CharList36 = new string(array);
}
return _CharList36;
}
}
private static List<string> SplitStringByLength(string str, int chunkSize)
{
List<string> list = new List<string>();
int i;
for (i = 0; i < str.Length / chunkSize; i++)
{
list.Add(str.Substring(i * chunkSize, chunkSize));
}
i = i * chunkSize;
if (i < str.Length - 1)
list.Add(str.Substring(i, str.Length - i));
return list;
}
private static String Encode36(ulong input)
{
if (input < 0) throw new ArgumentOutOfRangeException("input", input, "input cannot be negative");
char[] clistarr = CharList36.ToCharArray();
var result = new Stack<char>();
while (input != 0)
{
result.Push(clistarr[input % 36]);
input /= 36;
}
return new string(result.ToArray()).ToUpper();
}
private static ulong Decode36(string input)
{
var reversed = ReverseString(input.ToLower());
ulong result = 0;
int pos = 0;
foreach (char c in reversed)
{
result += (ulong)CharList36.IndexOf(c) * (ulong)Math.Pow(36, pos);
pos++;
}
return result;
}
private static string ReverseString(string text)
{
char[] cArray = text.ToCharArray();
string reverse = String.Empty;
for (int i = 0; i < cArray.Length / 2; i++)
{
char c = cArray[i];
cArray[i] = cArray[cArray.Length - 1 - i];
cArray[cArray.Length - 1 - i] = c;
}
return new string(cArray);
}
private static byte[] StringToBytes(string str)
{
byte[] bytes = new byte[str.Length * sizeof(char)];
System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
return bytes;
}
private static List<byte[]> SplitBytes(byte[] bytes, int length)
{
List<byte[]> result = new List<byte[]>();
int position = 0;
while (bytes.Length - position > length)
{
byte[] temp = new byte[length];
for (int i = 0; i < temp.Length; i++) temp[i] = bytes[i + position];
position += length;
result.Add(temp);
}
if (position < bytes.Length)
{
byte[] temp = new byte[bytes.Length - position];
for (int i = 0; i + position < bytes.Length; i++) temp[i] = bytes[i + position];
result.Add(temp);
}
return result;
}
private static string BytesToString(byte[] bytes)
{
char[] chars = new char[bytes.Length / sizeof(char)];
System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
return new string(chars);
}
private static byte[] JoinBytes(List<byte[]> listBytes)
{
int totalLength = 0;
foreach (byte[] bytes in listBytes) totalLength += bytes.Length;
byte[] result = new byte[totalLength];
int position = 0;
foreach (byte[] bytes in listBytes)
for (int i = 0; i < bytes.Length; i++)
{
result[position] = bytes[i];
position++;
}
return result;
}
#endregion
}

You can encode the resulting bytes using Base36 or another such binary-to-text encoding.