Develop Reference

Converting between string bit and string char out to ASCII

The problem is to convert non-ASCII characters into binary and vice versa
string of bits to string of char
string result = "";
while (value.Length > 0)
{ var first8 = value.Substring(0, 8);
value = value.Substring(8);
var number = Convert.ToInt64(first8, 2);
result += (char)number;
and
string of char to string of bits
string S = "";
byte[] asciiBytes = Encoding.ASCII.GetBytes(value);
for (int i = 0; i < asciiBytes.Length; i++)
for (int j = 0; j < 8; j++)
{
S += (asciiBytes[i] & 0x80) > 0 ? "1" : "0";
asciiBytes[i] <<= 1;
}
return S;
Can you correct my code if it is the best?

You could split the string into 8 character string, convert it to a byte using Convert.ToByte and then use Encoding.ASCII.GetString to convert the byte array to string.
var str = "0011111110110101001111110110111100111111110110110011111101101111";
var byteArray = Enumerable.Range(0, str.Length / 8)
.Select(x => Convert.ToByte(str.Substring(x * 8, 8), 2)).ToArray();
var convertedString = Encoding.ASCII.GetString(byteArray);
For 8-Bit
Encoding enc = Encoding.GetEncoding(1252);
var convertedString = enc.GetString(byteArray);
Output
?µ?o?Û?o

Incorrect CRC8 checksum computation

I got this class to compute the CRC8 checksum of a byte[]:
public static class Crc8
{
static byte[] table = new byte[256];
// x8 + x7 + x6 + x4 + x2 + 1
const byte poly = 0xd5;
public static byte ComputeChecksum(params byte[] bytes)
{
byte crc = 0;
if (bytes != null && bytes.Length > 0)
{
foreach (byte b in bytes)
{
crc = table[crc ^ b];
}
}
return crc;
}
static Crc8()
{
for (int i = 0; i < 256; ++i)
{
int temp = i;
for (int j = 0; j < 8; ++j)
{
if ((temp & 0x80) != 0)
{
temp = (temp << 1) ^ poly;
}
else
{
temp <<= 1;
}
}
table[i] = (byte)temp;
}
}
}
And in the Main I got:
static void Main(string[] args)
{
string number = "123456789";
Console.WriteLine(Convert.ToByte(Crc8.ComputeChecksum(StringToByteArray(number))).ToString("x2"));
Console.ReadLine();
}
private static byte[] StringToByteArray(string str)
{
ASCIIEncoding enc = new ASCIIEncoding();
return enc.GetBytes(str);
}
This results in 0xBC
However, according to: http://www.scadacore.com/field-tools/programming-calculators/online-checksum-calculator/
this is incorrect, because the checksum for the CheckSum8 Xor is 0x31.
What did I wrong there?

On the linked site only some 16 and 32 bit CRCs are listed, the
CheckSum8Xor is not a CRC. The 0xBC comes from a 8-bit CRC
called "CRC-8/DVB-S2", see http://reveng.sourceforge.net/crc-catalogue/1-15.htm

Ah, ok, so I've overiterpreted this checksum computation.
Well, in that case, it's easy:
public static byte Checksum8XOR(byte[] data)
{
byte checksum = 0x00;
for (int i = 0; i < data.Length; i++)
{
checksum ^= data[i];
}
return checksum;
}

How to convert this PHP function to C#?

I'd like to convert this function:
function DoHashPassword($username, $clear_password)
{
return strtoupper(bin2hex(strrev(hex2bin(strtoupper(hash("sha256",strtoupper(hash("sha256", strtoupper($username)).":".strtoupper($clear_password))))))));
}
to C# language.
How can I do that?
At the moment I'm at this point:
Remaining (in PHP)
strtoupper(bin2hex(strrev(hex2bin($password))));
What I've done (in C#)
public static string DoShaHashPassword256(string _email, string _password)
{
byte[] emailbyte = Encoding.ASCII.GetBytes(_email.ToUpper());
var sha_email = SHA256.Create();
byte[] bytehashemail = sha_email.ComputeHash(emailbyte);
_email = HexStringFromBytes(bytehashemail);
//now with password
byte[] passbyte = Encoding.ASCII.GetBytes(_email.ToUpper() + ":" + _password.ToUpper());
var sha_pass = SHA256.Create();
byte[] bytehashpass = sha_pass.ComputeHash(passbyte);
_password = HexStringFromBytes(bytehashpass).ToUpper();
return /* hashed password */
}
private static string HexStringFromBytes(byte[] bytes)
{
var sb = new StringBuilder();
foreach (byte b in bytes)
{
var hex = b.ToString("x2");
sb.Append(hex);
}
return sb.ToString();
}
I don't know how to go on now.

This is the answer to the question. Thanks for your bad votes to my question (you should help, not give bad vote and no answer.).
public static string DoShaHashPassword256(string _email, string _password)
{
byte[] emailbyte = Encoding.ASCII.GetBytes(_email.ToUpper());
var sha_email = SHA256.Create();
byte[] bytehashemail = sha_email.ComputeHash(emailbyte);
_email = HexStringFromBytes(bytehashemail);
//now with password
byte[] passbyte = Encoding.ASCII.GetBytes(_email.ToUpper() + ":" + _password.ToUpper());
var sha_pass = SHA256.Create();
byte[] bytehashpass = sha_pass.ComputeHash(passbyte);
_password = HexStringFromBytes(bytehashpass).ToUpper();
//hex2bin
var bindata = hex2bin(_password);
//strrev
char[] chararray = bindata.ToCharArray();
Array.Reverse(chararray);
var reversedstring = new string(chararray);
//bin2hex
byte[] bytes = Encoding.GetEncoding(1252).GetBytes(reversedstring);
string hexString = HexStringFromBytes(bytes);
return hexString.ToUpper();
}
private static string HexStringFromBytes(byte[] bytes)
{
var sb = new StringBuilder();
foreach (byte b in bytes)
{
var hex = b.ToString("x2");
sb.Append(hex);
}
return sb.ToString();
}
private static string hex2bin(string hexdata)
{
if (hexdata == null)
throw new ArgumentNullException("hexdata");
if (hexdata.Length % 2 != 0)
throw new ArgumentException("hexdata should have even length");
byte[] bytes = new byte[hexdata.Length / 2];
for (int i = 0; i < hexdata.Length; i += 2)
bytes[i / 2] = (byte)(HexValue(hexdata[i]) * 0x10
+ HexValue(hexdata[i + 1]));
return Encoding.GetEncoding(1252).GetString(bytes);
}
private static int HexValue(char c)
{
int ch = (int)c;
if (ch >= (int)'0' && ch <= (int)'9')
return ch - (int)'0';
if (ch >= (int)'a' && ch <= (int)'f')
return ch - (int)'a' + 10;
if (ch >= (int)'A' && ch <= (int)'F')
return ch - (int)'A' + 10;
throw new ArgumentException("Not a hexadecimal digit.");
}

encryption , String to Byte conversion

I have a string and i changed it to hex values , so i want to store them in the Byte array , but it gives me error of "Input String is not correct format". here is my code :
byte[] PlainText = new byte[16];
byte[] MasterKey = new byte[16];
string input = "Hello";
char[] values = input.ToCharArray();
int i =0;
foreach (char letter in values)
{
int value = Convert.ToInt32(letter);
string hexout = String.Format("{0:X}", value);
PlainText[i++] = Convert.ToByte(hexout);
}

Change your intial code
byte[] PlainText = new byte[16];
byte[] MasterKey = new byte[16];
string input = "Hello";
char[] values = input.ToCharArray();
int i =0;
string hexout=string.empty;
foreach (char letter in values)
{
int value = Convert.ToInt32(letter);
hexout+= String.Format("{0:X}", value);
}
plaintext=StringToByteArray(hexout);
for converting hex to byte array
public static byte[] StringToByteArray(String hex)
{
int NumberChars = hex.Length;
byte[] bytes = new byte[NumberChars / 2];
for (int i = 0; i < NumberChars; i += 2)
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
return bytes;
}
or
For parsing long string
public static byte[] StringToByteArray(String hex)
{
int NumberChars = hex.Length/2;
byte[] bytes = new byte[NumberChars];
using (var sr = new StringReader(hex))
{
for (int i = 0; i < NumberChars; i++)
bytes[i] =
Convert.ToByte(new string(new char[2]{(char)sr.Read(), (char)sr.Read()}), 16);
}
return bytes;
}

var bytes=System.Text.Encoding.UTF8.GetBytes(yourString);

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.