I have a function that generates a MD5 hash in C# like this:
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = md5.ComputeHash(data);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < result.Length; i++)
{
sb.Append(result[i].ToString("X2"));
}
return sb.ToString();
In java my function looks like this:
MessageDigest m = MessageDigest.getInstance("MD5");
m.update(bytes,0,bytes.length);
String hashcode = new BigInteger(1,m.digest()).toString(16);
return hashcode;
While the C# code generates: "02945C9171FBFEF0296D22B0607D522D" the java codes generates: "5a700e63fa29a8eae77ebe0443d59239".
Is there a way to generate the same md5 hash for the same bytearray?
On demand:
This is the testcode in java:
File file = new File(System.getProperty("user.dir") + "/HashCodeTest.flv");
byte[] bytes = null;
try {
bytes = FileUtils.getBytesFromFile(file);
} catch (IOException e) {
fail();
}
try {
generatedHashCode = HashCode.generate(bytes);
} catch (NoSuchAlgorithmException e) {
fail();
}
and this is my code in C#
var blob = GetBlobByHttpPostedFile(httpPostedFile);
var hashCode = Md5Factory.ConvertByteArray(blob);
private static byte[] GetBlobByHttpPostedFile(HttpPostedFile httpPostedFile)
{
var contentLength = httpPostedFile.ContentLength;
var result = new byte[contentLength];
var inputStream = httpPostedFile.InputStream;
inputStream.Read(result, 0, contentLength);
return result;
}
Cheers
That should be fine - although you could make the Java code simpler by just calling
byte[] digest = m.digest(bytes);
instead of calling update then digest.
Are you absolutely sure you've got the same data in both cases? Could you post sample programs showing this failing with the same hard-coded data?
EDIT: Here's the sort of test I was thinking of. These two programs give the same result:
C#:
using System;
using System.Security.Cryptography;
using System.Text;
class Test
{
static void Main()
{
byte[] bytes = { 0x35, 0x24, 0x76, 0x12 };
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = md5.ComputeHash(bytes);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < result.Length; i++)
{
sb.Append(result[i].ToString("x2"));
}
Console.WriteLine(sb);
}
}
Java:
import java.math.BigInteger;
import java.security.MessageDigest;
public class Test
{
public static void main(String[] args) throws Exception
{
byte[] bytes = { 0x35, 0x24, 0x76, 0x12 };
MessageDigest m = MessageDigest.getInstance("MD5");
byte[] digest = m.digest(bytes);
String hash = new BigInteger(1, digest).toString(16);
System.out.println(hash);
}
}
Hi I m using this code and it works
C# code :
public static string ConvertStringToMD5(string ClearText)
{
byte[] ByteData = Encoding.ASCII.GetBytes(ClearText);
//MD5 creating MD5 object.
MD5 oMd5 = MD5.Create();
//Hash değerini hesaplayalım.
byte[] HashData = oMd5.ComputeHash(ByteData);
//convert byte array to hex format
StringBuilder oSb = new StringBuilder();
for (int x = 0; x < HashData.Length; x++)
{
//hexadecimal string value
oSb.Append(HashData[x].ToString("x2"));
}
and Java code :
private String getMD5Digest(byte[] buffer) {
String resultHash = null;
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
byte[] result = new byte[md5.getDigestLength()];
md5.reset();
md5.update(buffer);
result = md5.digest();
StringBuffer buf = new StringBuffer(result.length * 2);
for (int i = 0; i < result.length; i++) {
int intVal = result[i] & 0xff;
if (intVal < 0x10) {
buf.append("0");
}
buf.append(Integer.toHexString(intVal));
}
resultHash = buf.toString();
} catch (NoSuchAlgorithmException e) {
}
return resultHash;
}
I came cross the similar issue that we were using Java MD5 Hash to determine whether a file has been processed. We found we cannot create same hash using .NET library. I tried all above suggestion, unfortunately it is not working for me.
The solution I found out later is: instead of create similar function in .NET, we call Java function directly in .NET. There is one great open source project called Ja.NET. Basically what i did is: create a Java class that create hash using the same code. compile it using Ja.NET javac. Then using bam compile the generated Java class file into DLL and use it in my .NET project.
I know this topic is old but I ran into the same issue just now and couldn't find an answer that worked for me. I was writing a patcher for a game and needed the md5 hashcode of files as a way to ensure that the files are up to date, but C# and Java gave me different strings although the files were identical.
Here's how I solved it:
C# Code:
public static string getMD5(string fullPath)
{
MD5 md5 = MD5.Create();
using (FileStream stream = new FileStream(fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
byte[] hash = md5.ComputeHash(stream);
StringBuilder sb = new StringBuilder();
for (int j = 0; j < hash.Length; j++)
{
sb.Append(hash[j].ToString("X2"));
}
return sb.ToString();
}
}
This creates a 32 character hex string. Apache Commons DigestUtils.md5Hex(InputStream) does the same, now the only different is that the C# example returns an uppercase string, so the solution is simply to convert the hash from the Java program to an uppercase string.
Java code:
public static String checkSumApacheCommons(String filePath)
{
String checksum = null;
try
{
checksum = DigestUtils.md5Hex(new FileInputStream(filePath));
}
catch (IOException ex)
{
ex.printStackTrace(System.out);
}
return checksum.toUpperCase();
}
The produced hashes look like F674865D8A44695A2443017CFA2B0C67.
Hope this helps someone.
Related
I am trying to decrypt a blowfish encrypted string with Bouncycastle in C#.
I am able to easily encrypt and decrypt my own string but, unfortunately, I have to decrypt a string that is generated by another system.
I AM able to recreate that same string with C# / Bouncycastle using the following but I have yet to decrypt it successfully.
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
...
static readonly Encoding Encoding = Encoding.UTF8;
public string BlowfishEncrypt(string strValue, string key)
{
try
{
BlowfishEngine engine = new BlowfishEngine();
PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
KeyParameter keyBytes = new KeyParameter(Encoding.GetBytes(key));
cipher.Init(true, keyBytes);
byte[] inB = Encoding.GetBytes(strValue);
byte[] outB = new byte[cipher.GetOutputSize(inB.Length)];
int len1 = cipher.ProcessBytes(inB, 0, inB.Length, outB, 0);
cipher.DoFinal(outB, len1);
return BitConverter.ToString(outB).Replace("-", "");
}
catch (Exception)
{
return "";
}
}
Below is what I have for decryption at the moment. The line that fails with error "pad block corrupted" is cipher.DoFinal(out2, len2);
public string BlowfishDecrypt(string name, string keyString)
{
BlowfishEngine engine = new BlowfishEngine();
PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
StringBuilder result = new StringBuilder();
cipher.Init(false, new KeyParameter(Encoding.GetBytes(keyString)));
byte[] out1 = Convert.FromBase64String(name);
byte[] out2 = new byte[cipher.GetOutputSize(out1.Length)];
int len2 = cipher.ProcessBytes(out1, 0, out1.Length, out2, 0);
cipher.DoFinal(out2, len2); //Pad block corrupted error happens here
String s2 = BitConverter.ToString(out2);
for (int i = 0; i < s2.Length; i++) {
char c = s2[i];
if (c != 0) {
result.Append(c.ToString());
}
}
return result.ToString();
}
Any idea what I might be doing wrong in BlowfishDecrypt()?
Note:
I converted the above (encrypt and decrypt) from a bouncycastle Java example I found somewhere; the encrypt works. The only difference I can see is that the Java example uses a StringBuffer where I use a StringBuilder.
Thank you, Artjom B!
byte[] out1 = Convert.FromBase64String(name);
Should have been
byte[] out1 = Hex.Decode(name);
From there, all I had to do was convert the Hex to a string.
I have about 16,000,000 urls, and I want to get hashcode about the urls.
I use System.Security.Cryptography.MD5 to create hashcode, refer this link
my code like this：
private string createMD5(string input)
{
using(MD5 md5 = MD5.Create())//the problem is here
{
byte[] inputBytes = System.Text.Encoding.Unicode.GetBytes(input);
byte[] hashBytes = md5.ComputeHash(inputBytes);
StringBuilder sb = new StringBuilder();
for(int i = 0;i < hashBytes.Length;i ++)
{
sb.Append(hashBytes[i].ToString("X2"));
}
return sb.ToString();
}
}
public void checkMD5Hash()
{
HashSet<string> urls = new HashSet<string>();
using (StreamReader reader = new StreamReader(#"D:/ScopePractice/SatoriExtractionReport/TransformData/WikipediaUrlList.tsv"))
{
//calcuate the MD5 hashcode for all urls
HashSet<string> set = new HashSet<string>();
string line = null;
while ((line = reader.ReadLine()) != null)
{
set.Add(createMD5(line));
}
double totalNum = 15844272;
Console.WriteLine("MD5Hash: {0}",set.Count() * 1.0 / totalNum * 1.0);
}
}
I use using(MD5 md5 = MD5.Create()),so I create many MD5 instances, it causes difference urls get same MD5 hashcode.
after that, I change my code, use the same MD5 instance to generate hashcode and the problem is solved.
static MD5 md5 = MD5.Create();
private string createMD5(string input)
{
byte[] inputBytes = System.Text.Encoding.Unicode.GetBytes(input);
byte[] hashBytes = md5.ComputeHash(inputBytes);
StringBuilder sb = new StringBuilder();
for(int i = 0;i < hashBytes.Length;i ++)
{
sb.Append(hashBytes[i].ToString("X2"));
}
return sb.ToString();
}
But I don't why different instance will cause this problem, please help me, thanks.
I have this C# code:
public static string Encript(string strData)
{
string hashValue = HashData(strData);
string hexHashData = ConvertStringToHex(hashValue);
return hexHashData;
}
public static string HashData(string textToBeEncripted)
{
//Convert the string to a byte array
Byte[] byteDataToHash = System.Text.Encoding.Unicode.GetBytes(textToBeEncripted);
//Compute the MD5 hash algorithm
Byte[] byteHashValue = new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(byteDataToHash);
return System.Text.Encoding.Unicode.GetString(byteHashValue);
}
public static string ConvertStringToHex(string asciiString)
{
string hex = "";
foreach (char c in asciiString)
{
int tmp = c;
hex += String.Format("{0:x2}", (uint) System.Convert.ToUInt32(tmp.ToString()));
}
return hex;
}
Here you can see an online version.As you can see for the string "test" I get the output "5c82e9e41c7599f790ef1d774b7e6bf"
And this is what I tried on php side
$a = "test";
$a = mb_convert_encoding($a, "UTF-16LE");
$a = md5($a);
echo $a;
But the value of the php code is "c8059e2ec7419f590e79d7f1b774bfe6".Why is not working?
Edit:Looks like the C# code is incorrect and needs to be replaced
The correct MD5 hash for 'test' is '098f6bcd4621d373cade4e832627b4f6' in PHP.
I tested it with this code in C#
public static string CreateMD5(string input)
{
// Use input string to calculate MD5 hash
using (System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create())
{
byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
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"));
}
return sb.ToString();
}
}
It will generate the same hash as PHP will, without the 'convert encoding' method you are using.
I believe converting the encoding is what is giving you a different answer, try it without
$a = mb_convert_encoding($a, "UTF-16LE");
The problem is that you are converting the result incorrectly in your C# code. If you put a breakpoint in the code after you call ComputeHash, and examine the value of byteHashValue, you'll see that it's c8059e2e....
Or, just add this code to your ComputeHash method:
Console.WriteLine(BitConverter.ToString(byteHashValue));
I would suggest rewriting your code to be:
public static string Encript(string strData)
{
string hashValue = HashData(strData);
return hashValue;
}
public static string HashData(string textToBeEncripted)
{
//Convert the string to a byte array
Byte[] byteDataToHash = System.Text.Encoding.Unicode.GetBytes(textToBeEncripted);
//Compute the MD5 hash algorithm
Byte[] byteHashValue = new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(byteDataToHash);
return BitConverter.ToString(byteHashValue).Replace("-", "");
}
Oh, and a side note: the word is "Encrypt," not "Encript."
The problem in your case is not the encoding, but your conversion to string on the C# side. As long as you use the same encoding everywhere, it should work as expected. But note, that most of the online hashers use ASCII encoding, whereas you use System.Text.Encoding.Unicode which is UTF-16, thus the results will differ from the online encoders.
The code below will give the same result as your PHP snippet (ie c8059e2ec7419f590e79d7f1b774bfe6)
public static void Main(string[] args)
{
string a = "test";
string en = HashData(a);
Console.WriteLine(en);
}
public static string HashData(string textToBeEncripted)
{
Byte[] byteDataToHash = System.Text.Encoding.Unicode.GetBytes(textToBeEncripted);
Byte[] byteHashValue = new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(byteDataToHash);
System.Text.StringBuilder s = new System.Text.StringBuilder();
foreach (var b in byteHashValue)
s.Append(b.ToString("x2"));
return s.ToString();
}
If you use System.Text.Encoding.ASCII instead, you will get 098f6bcd4621d373cade4e832627b4f6 as suggested in other answers. But then you'll have to use ASCII encoding in your PHP code as well.
This is because with UTF16 every character is represented by two bytes, and not only by one. Thus the byteDataToHash will have twice the size ([116, 0, 101, 0, 115, 0, 116, 0] vs [116, 101, 115, 116] in your case). And a different bytevector of course leads to a different hashvalue. But as said above, as long as all included components use the same encoding, it does not really matter which one you use.
I have a game made with Unity which is deployed in the WP store and I am trying to do the same for BB... however, after checking everything I have realized that I can´t post the score I have made, into the DB I host online...
I think it is because of the MD5 function but I am not sure which are the APIs, BB uses...
Can anyone help me out a little, here, please?
This is the MD5 function I have (written in C#)
using UnityEngine;
using System.Collections;
using System.Text;
using System;
#if UNITY_WP8
using System.Security.Cryptography;
using UnityEngine.Windows;
using UnityEngine.WindowsPhone;
#else
using System.Security.Cryptography;
#endif
public static class Md5Functions
{
#if UNITY_WP8
static string md5val;
// Use this for initialization
static void Start () {
md5val = Md5Sum("Hello World!");
}
static void OnGUI()
{
GUILayout.Label(md5val);
}
public static string Md5Sum(string strToEncrypt)
{
System.Text.UTF8Encoding ue = new System.Text.UTF8Encoding();
byte[] bytes = ue.GetBytes(strToEncrypt);
byte[] hashBytes = Crypto.ComputeMD5Hash(bytes);
string hashString = "";
for (int i = 0; i < hashBytes.Length; i++)
{
hashString += System.Convert.ToString(hashBytes[i], 16).PadLeft(2, '0');
}
return hashString.PadLeft(32, '0');
}
#else
public static string Md5Sum(string strToEncrypt)
{
System.Text.UTF8Encoding ue = new System.Text.UTF8Encoding();
byte[] bytes = ue.GetBytes(strToEncrypt);
// encrypt bytes
System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
byte[] hashBytes = md5.ComputeHash(bytes);
// Convert the encrypted bytes back to a string (base 16)
string hashString = "";
for (int i = 0; i < hashBytes.Length; i++)
{
hashString += System.Convert.ToString(hashBytes[i], 16).PadLeft(2, '0');
}
return hashString.PadLeft(32, '0');
}
#endif
}
Thanks!
I am trying to make use of a REST API using C#. The API creator has provided sample libraries in PHP, Ruby and Java. I am getting hung up on one part of it where I need to generate an HMAC.
Here's how it is done in the sample libraries they have provided.
PHP
hash_hmac('sha1', $signatureString, $secretKey, false);
Ruby
digest = OpenSSL::Digest::Digest.new('sha1')
return OpenSSL::HMAC.hexdigest(digest, secretKey, signatureString)
Java
SecretKeySpec signingKey = new SecretKeySpec(secretKey.getBytes(), HMAC_SHA1_ALGORITHM);
Mac mac = null;
mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
mac.init(signingKey);
byte[] bytes = mac.doFinal(signatureString.getBytes());
String form = "";
for (int i = 0; i < bytes.length; i++)
{
String str = Integer.toHexString(((int)bytes[i]) & 0xff);
if (str.length() == 1)
{
str = "0" + str;
}
form = form + str;
}
return form;
Here's my attempt in C#. It is not working. UPDATE: The C# example below works just fine. I found out that the real problem was due to some cross-platform differences in newline characters in my signatureString.
var enc = Encoding.ASCII;
HMACSHA1 hmac = new HMACSHA1(enc.GetBytes(secretKey));
hmac.Initialize();
byte[] buffer = enc.GetBytes(signatureString);
return BitConverter.ToString(hmac.ComputeHash(buffer)).Replace("-", "").ToLower();
an extension to Vimvq1987's answer:
return hashValue.ToString(); doesn't produce the output you want/need. You have to convert the bytes in the array hashValue to their hex-string representation.
Can be as simple as return BitConverter.toString(hashValue); (prints upper-case letters A-F) or if you like it a bit more complex:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
public static string Encode(string input, byte[] key)
{
HMACSHA1 myhmacsha1 = new HMACSHA1(key);
byte[] byteArray = Encoding.ASCII.GetBytes(input);
MemoryStream stream = new MemoryStream(byteArray);
return myhmacsha1.ComputeHash(stream).Aggregate("", (s, e) => s + String.Format("{0:x2}",e), s => s );
}
static void Main(string[] args)
{
byte[] key = Encoding.ASCII.GetBytes("abcdefghijklmnopqrstuvwxyz");
string input = "";
foreach (string s in new string[] { "Marry", " had", " a", " little", " lamb" })
{
input += s;
System.Console.WriteLine( Encode(input, key) );
}
return;
}
}
}
which prints
3545e064fb59bc4bfc02b6e1c3d4925c898aa504
3249f4c8468d4d67f465937da05b809eaff22fdb
87baaadf5d096677f944015e53d283834eb1e943
6325376820c29a09e3ab30db000033aa71d6927d
54579b0146e2476595381d837ee38863be358213
and I get the exact same result for
<?php
$secretKey = 'abcdefghijklmnopqrstuvwxyz';
$signatureString = '';
foreach( array('Marry',' had',' a',' little',' lamb') as $s ) {
$signatureString .= $s;
echo hash_hmac('sha1', $signatureString, $secretKey, false), "\n";
}
edit: Dmitriy Nemykin suggested the following edit
public static string Encode(string input, byte[] key)
{
byte[] byteArray = Encoding.ASCII.GetBytes(input);
using(var myhmacsha1 = new HMACSHA1(key))
{
var hashArray = myhmacsha1.ComputeHash(byteArray);
return hashArray.Aggregate("", (s, e) => s + String.Format("{0:x2}",e), s => s );
}
}
which was rejected. But as James already pointed out in a comment to this answer at the very least the using statement is a good point.
This site has some pretty good examples across languages: http://jokecamp.wordpress.com/2012/10/21/examples-of-creating-base64-hashes-using-hmac-sha256-in-different-languages/
The c# implementation at the time of writing is:
private string CreateToken(string message, string secret)
{
secret = secret ?? "";
var encoding = new System.Text.ASCIIEncoding();
byte[] keyByte = encoding.GetBytes(secret);
byte[] messageBytes = encoding.GetBytes(message);
using (var hmacsha256 = new HMACSHA256(keyByte))
{
byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
return Convert.ToBase64String(hashmessage);
}
}
Try this:
http://msdn.microsoft.com/en-us/library/system.security.cryptography.hmacsha1.aspx
quick and dirty code:
public string Encode(string input, byte [] key)
{
HMACSHA1 myhmacsha1 = new HMACSHA1(key);
byte[] byteArray = Encoding.ASCII.GetBytes( input );
MemoryStream stream = new MemoryStream( byteArray );
byte[] hashValue = myhmacsha1.ComputeHash(stream);
return hashValue.ToString();
}