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RC4 encrypting data when knowing how to decrypt it

Im currently working with an online API that sends me some users with a encrypted PIN that is encrypted with RC4. its sent in Hex(8) and ive managed to decrypt the hex into the int that it originally was, but i cant for the life of me reverse it to send an encrypted pin(is 4 digits long, pre enc) back. im not the sharpest tool in the shed when it comes to crypt especially not when its between data types so im hoping someone is abit more experianced.
My Classes for RC4:
Decrypt Function:
public string DecryptUserPin(Users user)
{
try
{
byte[] out_ = new byte[8];
crypto crypto = new crypto((long)user.UID);
byte[] bytes = BitConverter.GetBytes(int.Parse(user.PIN, NumberStyles.HexNumber));
crypto.crypto_rc4(ref bytes, ref out_, (long)bytes.Length);
return BitConverter.ToInt64(out_, 0).ToString();
}
catch (Exception ex)
{
Console.WriteLine("ERROR" + ex.ToString());
return (string)null;
}
}
Crypto class:
public class crypto
{
private string key = "Secret words ";
public rc4_key_t ctx;
public crypto(long userId)
{
this.key += userId.ToString();
byte length = (byte)this.key.Length;
byte[] numArray = new byte[256];
for (short index = 0; index < (short)256; ++index)
numArray[(int)index] = (byte)index;
this.ctx.x = (byte)0;
this.ctx.y = (byte)0;
byte index1 = 0;
byte index2 = 0;
for (short index3 = 0; index3 < (short)256; ++index3)
{
index2 = (byte)((int)this.key[(int)index1] + (int)numArray[(int)index3] + (int)index2 & (int)byte.MaxValue);
byte num = numArray[(int)index3];
numArray[(int)index3] = numArray[(int)index2];
numArray[(int)index2] = num;
index1 = (byte)(((uint)index1 + 1U) % (uint)length);
}
this.ctx.state = numArray;
}
public void crypto_rc4(ref byte[] in_, ref byte[] out_, long len)
{
byte index1 = this.ctx.x;
byte index2 = this.ctx.y;
byte[] numArray = new byte[8];
byte[] state = this.ctx.state;
for (short index3 = 0; (long)index3 < len; ++index3)
{
index1 = (byte)((int)index1 + 1 & (int)byte.MaxValue);
index2 = (byte)((int)state[(int)index1] + (int)index2 & (int)byte.MaxValue);
byte num1 = state[(int)index1];
state[(int)index1] = state[(int)index2];
state[(int)index2] = num1;
byte index4 = (byte)((int)state[(int)index1] + (int)state[(int)index2] & (int)byte.MaxValue);
byte num2 = (byte)((uint)in_[(int)index3] ^ (uint)state[(int)index4]);
numArray[(int)index3] = num2;
}
this.ctx.x = index1;
this.ctx.y = index2;
out_ = numArray;
}
}
Support Class:
public struct rc4_key_t
{
public byte[] state;
public byte x;
public byte y;
}

Accessing fields of List<Class> via string

I have a list of a class MyData which holds byte arrays. I am creating a function to which I can pass List and a string to access the fields and do some operations on them - primarily concatenation.
The part I am struggling with is accessing a class field via string.
I am unsure if I should be using Linq or reflection or a combination of the two.
I have a lot of data, so performance is also a consideration.
Thanks
public class MyData
{
public byte[] vertices;
public byte[] indicies;
}
public byte[] ProcessData(List<MyData> inData, string fieldName)
{
byteArray = new byte[inData.Sum(x => x."fieldName").Length];
offset = 0;
for (int i = 0; i < inData.Count; i++) {
Buffer.BlockCopy(inData[i]."fieldName", 0, ret, offset, inData[i]."fieldName".Length);
offset += inData."fieldName".Length;
}
return byteArray;
}
List<MyData> AllMyData = new List<MyData>();
//Load some data (omitted)
var AllVertices = ProcessData(AllMyData, "vertices");
var AllIndicies = ProcessData(AllMyData, "indicies");

public byte[] ProcessData(List<MyData> inData, string fieldName)
{
var field = inData.GetType().GetField(fieldName);
if (field == null)
throw new ArgumentException("Invalid field name", nameof(fieldName));
byte[] bytesField = field.GetValue(inData) as byte[];
var byteArray = new byte[bytesField.Sum().Length];
var offset = 0;
for (int i = 0; i < inData.Count; i++) {
Buffer.BlockCopy(bytesField[i], 0, ret, offset, bytesField.Length);
offset += bytesField.Length;
}
return byteArray;
}

If would be faster (than reflection) if it is OK to represent the field selection not as string, but as function:
public byte[] ProcessData(List<MyData> inData, Func<MyData, byte[]> field)
{
var byteArray = new byte[inData.Sum(x => field(x).Length)];
var offset = 0;
for (int i = 0; i < inData.Count; i++) {
Buffer.BlockCopy(field(inData[i]), 0, byteArray, offset, field(inData[i]).Length);
offset += field(inData[i]).Length;
}
return byteArray;
}
var allVertices = ProcessData(AllMyData, x => x.vertices);
var allIndicies = ProcessData(AllMyData, x => x.indicies);

C# hex to byte array loop

I have the following function:
public void SetTagData(string _data)
{
string data = _data;
byte[] ba = Encoding.Default.GetBytes(data);
string hexString = BitConverter.ToString(ba);
hexString = hexString.Replace("-", "");
var blockStart = 0;
var bufferHexBlocks = String.Empty;
try
{
for (var i = 0; i < hexString.Length; i++)
{
var byteList = new List<byte>();
byte[] datablockKey = ConvertHelpers.ConvertHexStringToByteArray(i.ToString().PadLeft(2, '0'));
var block = hexString.Substring(blockStart, 8);
byte[] datablockValue = ConvertHelpers.ConvertHexStringToByteArray(block);
byteList.AddRange(datablockKey);
byteList.AddRange(datablockValue);
_reader.Protocol("wb", byteList.ToArray());
blockStart += 8;
}
}
catch (Exception ex)
{
console.log(ex.message);
}
}
The data coming in is a bunch of hex as a string. I need to split this hex string into batches of 8 characters, append an incrementing 0 padded hex number from 00 to 1f and send this new string as a byte array to the _reader.Protocol function, which accepts a string wb as first parameter and the block as the second.
For example incoming data is:
string data = "3930313B36313B5350542D53504C3B3830303B3B352E373B3B303B303B3B3B34353036383B4E3B4E3B"
I need to send the following to the _reader.Protocol object:
(incremented padded hex 01, 02, 03, ... , 0f) and the first 8 characters of the data string, then the next, and so on as a byte array.
[013930313B], [0236313B53], etc.
I think I'm getting close... but missing something...
My problem at the moment is that I can't figure out how to loop in blocks of 8 and if the hex string is say 82 characters instead of 80 (multiple of 8), then how would I grab the last two characters without getting a IndexOutofRange exception.
Note: This is for a Windows CE application, so no new C# features please.

This below will work fine in conjunction with this answer and the sample string data given.
public static byte[] Parse(string data)
{
var count = data.Length / 8; //Might be worth throwing exception with any remainders unless you trust the source.
var needle = 0;
List<byte> result = new List<byte>(); //Inefficient but I'm being lazy
for (int i = 0; i < count; i++)
{
char[] buffer = new char[8];
data.CopyTo(needle, buffer, 0, buffer.Length);
//To get around the odd number when adding the prefixed count byte, send the hex string to the convert method separately.
var bytes = ConvertHexStringToByteArray(new string(buffer)); //Taken From https://stackoverflow.com/a/8235530/6574422
//As the count is less than 255, seems safe to parse to single byte
result.Add(byte.Parse((i + 1).ToString()));
result.AddRange(bytes);
needle += 8;
}
return result.ToArray();
}

I'm figured it out. It might not be the most efficient solution but it works just fine. I did it using a for loop inside a for loop.
In case anyone is interested here is the final code:
public void SetTagData(string _data)
{
string data = _data;
byte[] ba = Encoding.Default.GetBytes(data);
string hexString = BitConverter.ToString(ba);
hexString = hexString.Replace("-", "");
var blockStart = 0;
try
{
_reader.Protocol("s");
for(var count = 0; count < 16; count++)
{
var byteList = new List<byte>();
byte[] datablockKey = ConvertHelpers.ConvertHexStringToByteArray(count.ToString("X2"));
byteList.AddRange(datablockKey);
for (var innerCount = 0; innerCount < 4; innerCount++)
{
var block = String.Empty;
if (!String.IsNullOrEmpty(hexString.Substring(blockStart, 2)))
{
block = hexString.Substring(blockStart, 2);
}
else
{
block = "20";
}
byte[] datablockValue = ConvertHelpers.ConvertHexStringToByteArray(block);
byteList.AddRange(datablockValue);
blockStart += 2;
}
_reader.Protocol("wb", byteList.ToArray());
}
}
catch (Exception)
{
}
}

How can I get the data of 8bit wav file

I'm making a demo about sound in WindowsForm, I created 3 classes for taking data of wave file. Code is below:
RiffBlock
public class RiffBlock
{
private byte[] riffID;
private uint riffSize;
private byte[] riffFormat;
public byte[] RiffID
{
get { return riffID; }
}
public uint RiffSize
{
get { return (riffSize); }
}
public byte[] RiffFormat
{
get { return riffFormat; }
}
public RiffBlock()
{
riffID = new byte[4];
riffFormat = new byte[4];
}
public void ReadRiff(FileStream inFS)
{
inFS.Read(riffID, 0, 4);
BinaryReader binRead = new BinaryReader(inFS);
riffSize = binRead.ReadUInt32();
inFS.Read(riffFormat, 0, 4);
}
}
FormatBlock
public class FormatBlock
{
private byte[] fmtID;
private uint fmtSize;
private ushort fmtTag;
private ushort fmtChannels;
private uint fmtSamplesPerSec;
private uint fmtAverageBytesPerSec;
private ushort fmtBlockAlign;
private ushort fmtBitsPerSample;
public byte[] FmtID
{
get { return fmtID; }
}
public uint FmtSize
{
get { return fmtSize; }
}
public ushort FmtTag
{
get { return fmtTag; }
}
public ushort Channels
{
get { return fmtChannels; }
}
public uint SamplesPerSec
{
get { return fmtSamplesPerSec; }
}
public uint AverageBytesPerSec
{
get { return fmtAverageBytesPerSec; }
}
public ushort BlockAlign
{
get { return fmtBlockAlign; }
}
public ushort BitsPerSample
{
get { return fmtBitsPerSample; }
}
public FormatBlock()
{
fmtID = new byte[4];
}
public void ReadFmt(FileStream inFS)
{
inFS.Read(fmtID, 0, 4);
BinaryReader binRead = new BinaryReader(inFS);
fmtSize = binRead.ReadUInt32();
fmtTag = binRead.ReadUInt16();
fmtChannels = binRead.ReadUInt16();
fmtSamplesPerSec = binRead.ReadUInt32();
fmtAverageBytesPerSec = binRead.ReadUInt32();
fmtBlockAlign = binRead.ReadUInt16();
fmtBitsPerSample = binRead.ReadUInt16();
// This accounts for the variable format header size
// 12 bytes of Riff Header, 4 bytes for FormatId, 4 bytes for FormatSize & the Actual size of the Format Header
inFS.Seek(fmtSize + 20, System.IO.SeekOrigin.Begin);
}
}
DataBlock
public class DataBlock
{
private byte[] dataID;
private uint dataSize;
private Int16[] data;
private int dataNumSamples;
public byte[] DataID
{
get { return dataID; }
}
public uint DataSize
{
get { return dataSize; }
}
public Int16 this[int pos]
{
get { return data[pos]; }
}
public int NumSamples
{
get { return dataNumSamples; }
}
public DataBlock()
{
dataID = new byte[4];
}
public void ReadData(FileStream inFS)
{
inFS.Read(dataID, 0, 4);
BinaryReader binRead = new BinaryReader(inFS);
dataSize = binRead.ReadUInt32();
data = new Int16[dataSize];
inFS.Seek(40, SeekOrigin.Begin);
dataNumSamples = (int)(dataSize / 2);
for (int i = 0; i < dataNumSamples; i++)
{
data[i] = binRead.ReadInt16();
}
}
}
It works ok with only 16bit wave file, but when I choose a 8 bit wav file or another, the result of this command dataSize = binRead.ReadUInt32();is only 4 although the file size is big.
How I can get the data of 8bit, 24bit... wav file?
Some solutions is appreciated, thank you very much.

Your reading methodology is flawed. The length is correct but for an 8 bits per sample file you should be reading bytes not words; as it stands the data will be incorrect and the value returned by the NumSamples property will be wrong.
In my case, the sub chunk size is 1160, the number of channels is 1 (mono) and the bits per sample is 8 (byte). You will need to decode the bits per sample and adjust your reading accordingly. For the WAV file I used, your program allocated a data array the correct length but 16 bit, divided the data length by 2 and called this the number of samples (wrong, it should be 1160) and then proceeded to read 580 word values from the stream.
Edit: My ancient code will not cut it in the modern age (I seem to recall having to modify it some years ago to cope with at least one additional chunk type but the details escape me).
This is what you get; anything more and your question should read "Could someone write me a program to load WAV files", as it is, we are way beyond the original question and it is time for you to knuckle down and make it work how you need it to :-)
References:
http://www.neurophys.wisc.edu/auditory/riff-format.txt
http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html
http://www.shikadi.net/moddingwikiResource_Interchange_File_Format_(RIFF)
http://soundfile.sapp.org/doc/WaveFormat/
All are very useful.
///<summary>
///Reads up to 16 bit WAV files
///</summary>
///<remarks> Things have really changed in the last 15 years</remarks>
public class RiffLoader
{
public enum RiffStatus { Unknown = 0, OK, FileError, FormatError, UnsupportedFormat };
LinkedList<Chunk> chunks = new LinkedList<Chunk>();
RiffStatus status = RiffStatus.Unknown;
List<String> errorMessages = new List<string>();
String source;
public String SourceName { get { return source; } }
public RiffStatus Status { get { return status; } }
public String[] Messages { get { return errorMessages.ToArray(); } }
enum chunkType { Unknown = 0, NoMore, Riff, Fmt, Fact, Data, Error = -1 };
static Int32 scan32bits(byte[] source, int offset = 0)
{
return source[offset] | source[offset + 1] << 8 | source[offset + 2] << 16 | source[offset + 3] << 24;
}
static Int32 scan16bits(byte[] source, int offset = 0)
{
return source[offset] | source[offset + 1] << 8;
}
static Int32 scan8bits(byte[] source, int offset = 0)
{
return source[offset];
}
abstract class Chunk
{
public chunkType Ident = chunkType.Unknown;
public int ByteCount = 0;
}
class RiffChunk : Chunk
{
public RiffChunk(int count)
{
this.Ident = chunkType.Riff;
this.ByteCount = count;
}
}
class FmtChunk : Chunk
{
int formatCode = 0;
int channels = 0;
int samplesPerSec = 0;
int avgBytesPerSec = 0;
int blockAlign = 0;
int bitsPerSample = 0;
int significantBits = 0;
public int Format { get { return formatCode; } }
public int Channels { get { return channels; } }
public int BlockAlign { get { return blockAlign; } }
public int BytesPerSample { get { return bitsPerSample / 8 + ((bitsPerSample % 8) > 0 ? 1 : 0); } }
public int BitsPerSample
{
get
{
if (significantBits > 0)
return significantBits;
return bitsPerSample;
}
}
public FmtChunk(byte[] buffer) : base()
{
int size = buffer.Length;
// if the length is 18 then buffer 16,17 should be 00 00 (I don't bother checking)
if (size != 16 && size != 18 && size != 40)
return;
formatCode = scan16bits(buffer, 0);
channels = scan16bits(buffer, 2);
samplesPerSec = scan32bits(buffer, 4);
avgBytesPerSec = scan32bits(buffer, 8);
blockAlign = scan16bits(buffer, 12);
bitsPerSample = scan16bits(buffer, 14);
if (formatCode == 0xfffe) // EXTENSIBLE
{
if (size != 40)
return;
significantBits = scan16bits(buffer, 18);
// skiping speaker map
formatCode = scan16bits(buffer, 24); // first two bytes of the GUID
// the rest of the GUID is fixed, decode it and check it if you wish
}
this.Ident = chunkType.Fmt;
this.ByteCount = size;
}
}
class DataChunk : Chunk
{
byte[] samples = null;
///<summary>
///Create a data chunk
///<para>
///The supplied buffer must be correctly sized with zero offset and must be purely for this class
///</para>
///<summary>
///<param name="buffer">source array</param>
public DataChunk(byte[] buffer)
{
this.Ident = chunkType.Data;
this.ByteCount = buffer.Length;
samples = buffer;
}
public enum SampleStatus { OK, Duff }
public class Samples
{
public SampleStatus Status = SampleStatus.Duff;
public List<int[]> Channels = new List<int[]>();
#if false // debugger helper method
/*
** Change #if false to #if true to include this
** Break at end of GetSamples on "return retval"
** open immediate window and type retval.DumpLast(16)
** look in output window for dump of last 16 entries
*/
public int DumpLast(int count)
{
for (int i = Channels[0].Length - count; i < Channels[0].Length; i++)
Console.WriteLine(String.Format("{0:X4} {1:X4},{2:X4}", i, Channels[0][i], Channels[1][i]));
return 0;
}
#endif
}
/*
** Return the decoded samples
*/
public Samples GetSamples(FmtChunk format)
{
Samples retval = new Samples();
int samplesPerChannel = this.ByteCount / (format.BytesPerSample * format.Channels);
int mask = 0, sign=0;
int [][] samples = new int [format.Channels][];
for (int c = 0; c < format.Channels; c++)
samples[c] = new int[samplesPerChannel];
if (format.BitsPerSample >= 8 && format.BitsPerSample <= 16) // 24+ is left as an excercise
{
sign = (int)Math.Floor(Math.Pow(2, format.BitsPerSample - 1));
mask = (int)Math.Floor(Math.Pow(2, format.BitsPerSample)) - 1;
int offset = 0, index = 0;
int s = 0;
while (index < samplesPerChannel)
{
for (int c = 0; c < format.Channels; c++)
{
switch (format.BytesPerSample)
{
case 1:
s = scan8bits(this.samples, offset) & mask;
break;
case 2:
s = scan16bits(this.samples, offset) & mask;
break;
}
// sign extend the data to Int32
samples[c][index] = s | ((s & sign) != 0 ? ~mask : 0);
offset += format.BytesPerSample;
}
++index;
}
retval.Channels = new List<int[]>(samples);
retval.Status = SampleStatus.OK;
}
return retval;
}
}
class FactChunk : Chunk
{
int samplesPerChannel;
public int SamplesPerChannel { get { return samplesPerChannel; } }
public FactChunk(byte[] buffer)
{
this.Ident = chunkType.Fact;
this.ByteCount = buffer.Length;
if (buffer.Length >= 4)
samplesPerChannel = scan32bits(buffer);
}
}
class DummyChunk : Chunk
{
public DummyChunk(int size, chunkType type = chunkType.Unknown)
{
this.Ident = type;
this.ByteCount = size;
}
}
public RiffLoader(String fileName)
{
source = fileName;
try
{
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
using (BinaryReader reader = new BinaryReader(fs))
{
Chunk c = getChunk(fs, reader);
if (c.Ident != chunkType.Riff)
{
status = RiffStatus.FileError;
errorMessages.Add(String.Format("Error loading \"{0}\": No valid header"));
}
chunks.AddLast(c);
c = getChunk(fs, reader);
if (c.Ident != chunkType.Fmt)
{
status = RiffStatus.FileError;
errorMessages.Add(String.Format("Error loading \"{0}\": No format chunk"));
}
chunks.AddLast(c);
/*
** From now on we just keep scanning to the end of the file
*/
while (fs.Position < fs.Length)
{
c = getChunk(fs, reader);
switch (c.Ident)
{
case chunkType.Fact:
case chunkType.Data:
chunks.AddLast(c);
break;
case chunkType.Unknown:
break; // skip it - don't care what it is
}
}
FmtChunk format = null;
foreach (var chunk in chunks)
{
switch(chunk.Ident)
{
case chunkType.Fmt:
format = chunk as FmtChunk;
break;
case chunkType.Data:
if (format != null)
{
DataChunk dc = chunk as DataChunk;
var x = dc.GetSamples(format);
}
break;
}
}
}
}
catch (Exception e)
{
status = RiffStatus.FileError;
errorMessages.Add(String.Format("Error loading \"{0}\": {1}", e.Message));
}
}
/*
** Get a chunk of data from the file - knows nothing of the internal format of the chunk.
*/
Chunk getChunk(FileStream stream, BinaryReader reader)
{
byte[] buffer;
int size;
buffer = reader.ReadBytes(8);
if (buffer.Length == 8)
{
String prefix = new String(Encoding.ASCII.GetChars(buffer, 0, 4));
size = scan32bits(buffer, 4);
if (size + stream.Position <= stream.Length) // skip if there isn't enough data
{
if (String.Compare(prefix, "RIFF") == 0)
{
/*
** only "WAVE" type is acceptable
**
** Don't read size bytes or the entire file will end up in the RIFF chunk
*/
if (size >= 4)
{
buffer = reader.ReadBytes(4);
String ident = new String(Encoding.ASCII.GetChars(buffer, 0, 4));
if (String.CompareOrdinal(ident, "WAVE") == 0)
return new RiffChunk(size - 4);
}
}
else if (String.Compare(prefix, "fmt ") == 0)
{
if (size >= 16)
{
buffer = reader.ReadBytes(size);
if (buffer.Length == size)
return new FmtChunk(buffer);
}
}
else if (String.Compare(prefix, "fact") == 0)
{
if (size >= 4)
{
buffer = reader.ReadBytes(4);
if (buffer.Length == size)
return new FactChunk(buffer);
}
}
else if (String.Compare(prefix, "data") == 0)
{
// assume that there has to be data
if (size > 0)
{
buffer = reader.ReadBytes(size);
if ((size & 1) != 0) // odd length?
{
if (stream.Position < stream.Length)
reader.ReadByte();
else
size = -1; // force an error - there should be a pad byte
}
if (buffer.Length == size)
return new DataChunk(buffer);
}
}
else
{
/*
** there are a number of weird and wonderful block types - assume there has to be data
*/
if (size > 0)
{
buffer = reader.ReadBytes(size);
if ((size & 1) != 0) // odd length?
{
if (stream.Position < stream.Length)
reader.ReadByte();
else
size = -1; // force an error - there should be a pad byte
}
if (buffer.Length == size)
{
DummyChunk skip = new DummyChunk(size);
return skip;
}
}
}
}
}
return new DummyChunk(0, chunkType.Error);
}
}
You will need to add properties as required and code to navigate the returned linked list. Particular properties you may need are the sample rates in the format block, assuming you are going to process the data in some way.
Adding 24 to 32 bits is simple, if you need to go beyond 32 bits you will have to switch to int64's.
I have tested it with some good samples from http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Samples.html, as well as your 8 bit file, and it decodes OK and seems to have the correct data.
You should be more than capable of making it work now, good luck.
Edit (again, like the proverbial dog...):
Of course, I should have sign extended the value, so DataChunk.GetSamples() now does that. Looking at the Codeproject files (it isn't the greatest code by the way, but the guy does say that he is only just learning C#, so fair play for tackling a graphical user control) it is obvious that the data is signed. It's a shame that he didn't standardise his source to be an array of Int32's, then it wouldn't matter how many bits the WAV was encoded in.

You could use the Naudio library:
https://naudio.codeplex.com/ (take a look at their website, there are quite a lot of tutorials).
Hope this helps :).

Trying to reproduce PHP's pack("H*") function in C#

this is my code in C# :
public static String MD5Encrypt(String str, Boolean raw_output=false)
{
// Use input string to calculate MD5 hash
String output;
MD5 md5 = System.Security.Cryptography.MD5.Create();
byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(str);
byte[] hashBytes = md5.ComputeHash(inputBytes);
// Convert the byte array to hexadecimal string
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hashBytes.Length; i++)
{
sb.Append(hashBytes[i].ToString("x2"));
}
output = sb.ToString();
if (raw_output)
{
output = pack(output);
}
return output;
}
public static String pack(String S)
{
string MultiByte = "";
for (int i = 0; i <= S.Length - 1; i += 2)
{
MultiByte += Convert.ToChar(HexToDec(S.Substring(i, 2)));
}
return MultiByte;
}
private static int HexToDec(String hex)
{
//Int32.Parse(hexString, System.Globalization.NumberStyles.HexNumber);
return Convert.ToInt32(hex, 16);
}
To reproduce what is done in php by this way :
md5($str, true);
OR
pack('H*', md5( $str ));
I tried many things but can't get the same on the two sides in some cases of word.
For example, Trying this test on the string "8tv7er5j"
PHP Side :
9c36ad446f83ca38619e12d9e1b3c39e <= md5("8tv7er5j");
œ6­DoƒÊ8ažÙá³Ãž <= md5("8tv7er5j", true) or pack("H*", md5("8tv7er5j"))
C# Side :
9c36ad446f83ca38619e12d9e1b3c39e <= MD5Encrypt("8tv7er5j")
6­DoÊ8aÙá³Ã <= MD5Encrypt("8tv7er5j", true) or pack( MD5Encrypt("8tv7er5j") )
Why ? Encoding problem ?
EDIT 1 :
I have the good result, but bad encoded with this this function for pack() :
if ((hex.Length % 2) == 1) hex += '0';
byte[] bytes = new byte[hex.Length / 2];
for (int i = 0; i < hex.Length; i += 2)
{
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
}
return bytes;
So, System.Text.Encoding.UTF8.GetString(bytes) give me :
�6�Do��8a���Þ
And System.Text.Encoding.ASCII.GetString(bytes)
?6?Do??8a??????
...

I encountered same scenario where I am in need of php's pack-unpack-md5 functions in C#. Most important was that I need to match out of all these 3 functions with php.
I created my own functions and then validated(verified) my output with functions at onlinephpfunctions.com. The output was same when I parsed with DefaultEncoding. FYI, I checked my application's encoding(Encoding.Default.ToString()) and it was System.Text.SBCSCodePageEncoding
Pack
private static string pack(string input)
{
//only for H32 & H*
return Encoding.Default.GetString(FromHex(input));
}
public static byte[] FromHex(string hex)
{
hex = hex.Replace("-", "");
byte[] raw = new byte[hex.Length / 2];
for (int i = 0; i < raw.Length; i++)
{
raw[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
}
return raw;
}
MD5
private static string md5(string input)
{
byte[] asciiBytes = Encoding.Default.GetBytes(input);
byte[] hashedBytes = MD5CryptoServiceProvider.Create().ComputeHash(asciiBytes);
string hashedString = BitConverter.ToString(hashedBytes).Replace("-", "").ToLower();
return hashedString;
}
Unpack
private static string unpack(string p1, string input)
{
StringBuilder output = new StringBuilder();
for (int i = 0; i < input.Length; i++)
{
string a = Convert.ToInt32(input[i]).ToString("X");
output.Append(a);
}
return output.ToString();
}
PS: User can enhance these functions with other formats

I guess that PHP defaults to Latin1 so the code should look like :
public static String PhpMd5Raw(string str)
{
var md5 = System.Security.Cryptography.MD5.Create();
var inputBytes = System.Text.Encoding.ASCII.GetBytes(str);
var hashBytes = md5.ComputeHash(inputBytes);
var latin1Encoding = System.Text.Encoding.GetEncoding("ISO-8859-1");
return latin1Encoding.GetString(hashBytes);
}

If you are going to feed the result as a key for HMAC-SHA1 hashing keep it as bytes[] and initialize the HMACSHA1 with the return value of this function: DO NOT convert it to a string and back to bytes, I have spent hours because of this mistake.
public static byte[] PackH(string hex)
{
if ((hex.Length % 2) == 1) hex += '0';
byte[] bytes = new byte[hex.Length / 2];
for (int i = 0; i < hex.Length; i += 2)
{
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
}
return bytes;
}

I know this is an old question. I am posting my answer for anyone who might reach this page searching for it.
The following code is the full conversion of the pearl function pack("H*") to c#.
public static String Pack(String input)
{
input = input.Replace("-", " ");
byte[] hashBytes = new byte[input.Length / 2];
for (int i = 0; i < hashBytes.Length; i++)
{
hashBytes[i] = Convert.ToByte(input.Substring(i * 2, 2), 16);
}
return Encoding.UTF7.GetString(hashBytes); // for perl/php
}

I'm sorry. I didn't go with the questions completely. But if php code is as below,
$testpack = pack("H*" , "you value");
and if can't read the $testpack values(due to some non support format), then first do base64_encode as below and echo it.
echo base64_encode($testpack);
Then use Risky Pathak answer. For complete this answer I'll post his answer with some small modification like base 64 encoding etc.
var hex = "you value";
hex = hex.Replace("-", "");
byte[] raw = new byte[hex.Length / 2];
for (int i = 0; i < raw.Length; i++)
{
raw[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
}
var res = Convert.ToBase64String(raw);
Console.WriteLine(res);
Now if you compare both of values, those should be similar.
And all credit should go to the Risky Pathak answer.

The same in c# can be reached with Hex.Decode() method.
And bin2hex() in php is Hex.Encode().