My job is to rewrite a bunch of Java codes is C#.
This is the JAVA code:
public static String CreateMD5(String str) {
try {
byte[] digest = MessageDigest.getInstance("MD5").digest(str.getBytes("UTF-8"));
StringBuffer stringBuffer = new StringBuffer();
for (byte b : digest) {
// i can not understand here
stringBuffer.append(Integer.toHexString((b & 255) | 256).substring(1, 3));
}
return stringBuffer.toString();
} catch (UnsupportedEncodingException | NoSuchAlgorithmException unused) {
return null;
}
}
Ok.As you can see this code is trying to make MD5 hash.But the thing i can not understand is the part that i have shown.
I tried this code in C# to rewrite this JAVA code:
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();
}
}
Well both codes are making MD5 hash strings but the results are different.
There is a difference in encoding between the two code snippets you've shown - your Java code uses UTF-8, but your C# code uses ASCII. This will result in a different MD5 hash computation.
Change your C# code from:
byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
to:
byte[] inputBytes = System.Text.Encoding.UTF8.GetBytes(input);
This should™ fix your problem, provided there are no other code conversion errors.
Related
I have a strange problem in getting equivalent hash code from C# code translated into Java. I don't know, what MessageDigest update method do. It should only update the contents of digest and should compute hash after calling digest.
Same thing I am doing in C# with SHAManaged512.ComputeHash(content). But I am not getting same hash code.
Following is the Java code.
public static String hash(String body, String secret) {
try {
MessageDigest md = MessageDigest.getInstance("SHA-512");
md.update(body.getBytes("UTF-8"));
byte[] bytes = md.digest(secret.getBytes("UTF-8"));
StringBuilder sb = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
} catch (Exception e) {
throw new RuntimeException();
}
}
Following is C# Code
private byte[] ComputeContentHash(string contentBody)
{
using (var shaM = new SHA512Managed())
{
var content = string.Concat(contentBody, Options.SecretKey);
var hashedValue = shaM.ComputeHash(ToJsonStream(content));
return hashedValue;
}
}
public static Stream ToJsonStream(object obj)
{
return new MemoryStream(Encoding.Unicode.GetBytes(obj.ToString()));
}
I had the exact same issue. Its been two years since you asked but just in case someone comes across this question, here's the solution
public static string encryptHash(string APIkey, string RequestBodyJson)
{
var secretBytes = Encoding.UTF8.GetBytes(APIkey);
var saltBytes = Encoding.UTF8.GetBytes(RequestBodyJson);
using (var sHA256 = new SHA256Managed())
{
byte[] bytes = sHA256.ComputeHash(saltBytes.Concat(secretBytes).ToArray());
//convert to hex
StringBuilder builder = new StringBuilder();
for (int i = 0; i < bytes.Length; i++)
{
builder.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
}
return builder.ToString();
}
}
The solution was to put first Secret Key and concate it with pay load data.
Encoding.Unicode (which you are using in the C# ToJsonStream method) is not UTF8. It's UTF16. See MSDN. (Also keep in mind that UTF16 can be little or big endian.) You're looking for Encoding.UTF8.
First thing to do is check if the byte array you're hashing is the same.
private String getString(byte[] bytes)
{
StringBuffer sb = new StringBuffer();
for (int i = 0; i < bytes.length; i++)
{
byte b = bytes[i];
sb.append(0xFF & b);
}
return sb.toString();
}
public String encrypt(String source)
{
try
{
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] bytes = md.digest(source.getBytes());
return getString(bytes);
}
catch (Exception e)
{
e.printStackTrace(); }
return null;
}
If my text = "test"
The First Part toString()) produces a value of "Encryption$2#6966b26b"
And the second part then gets that and produces a value of "91431072057033211115202222781313839180246"
But why is the md5 a number and not 31f521a06d5060d1f38159c74a1f7cf2 or something similar?
The function "encrypt()" returns a MD5 hash. You should rename it to "hash", because hashing != encrypting.
If you want to encrypt a string, you can look here: https://gist.github.com/bricef/2436364
It's clearly stated in code yuou are using MD5 hashing algorithm
Now your question is why:
But why is the md5 a number and not 31f521a06d5060d1f38159c74a1f7cf2 or something similar?
your answer is simple, look at code which generates you string from your byte array.
byte b = bytes[i];
sb.append(0xFF & b);
you take byte, ie 0x20 then you perform logical and operation with integer 0x255 and then you add decimal representation of result yo your StringBuilder.
What you want to do is more like
sb.append(Integer.toHexString(0xff&b));
I would say MD5 hash, because the code says MessageDigest.getInstance("MD5") :D
I want to implement SHA512 hashing using a salt. I started here, leading to this mcve:
import java.security.MessageDigest;
import org.junit.Test;
public class Sha512Mcve {
private final String ENCODING = "ISO-8859-1";
#Test
public void test() {
System.out.println(computeHashFor("whatever"));
}
private String computeHashFor(String toHash) {
String salt = "salt";
MessageDigest md;
try {
md = MessageDigest.getInstance("SHA-512");
// md.update(salt.getBytes(ENCODING));
byte[] bytes = md.digest(toHash.getBytes(ENCODING));
return toUnixRepresentation(salt, bytes);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private String toUnixRepresentation(String salt, byte[] bytes) {
StringBuilder sb = new StringBuilder();
sb.append("$6$");
sb.append(salt);
sb.append("$");
for (int i = 0; i < bytes.length; i++) {
int c = bytes[i] & 0xFF;
if (c < 16) sb.append("0");
sb.append(Integer.toHexString(c));
}
return sb.toString();
}
}
Thing is: when I leave the line md.update() commented out, this code gives me the exact same results as some online hash generators (like this one).
For example, hashing the word "whatever" gives a hash value ae3d....63a.
But when I run my code with that salt operation; I get different results (again compared against that online tool, which allows to set a salt string, too).
My implementation results in 413...623; the online tool says F25...686.
Any explanation in which way "salting" leads to "implementation specific" results?
Is there something I should do differently in my code?
Salt before or after?
What the calculator does when you set the salt option
whateversalt
What you are doing in your code
saltwhatever
resutls from the calculator
whateversalt
F2527142C752B05467EE53B44735397F5B4C870DF0F154A0CF3AC23B31CF42EE7E1002D326B57DF60ED4B7449CF101290BDC0BECCB677AAAD846CFBE140DF686
saltwhatever
41333B9BAFC14CB3D1106D72A5D461F348B9EA1304A82989E00E5FC2D3239339492FCA12ED5EBF5F6802955C95B5F7ADA4CA035A911C2F29ABE905C3923CF623
Therefore to match the calculation you just have to reverse the order and add the salt last
md.update(toHash.getBytes(ENCODING));
byte[] bytes = md.digest(salt.getBytes(ENCODING));
Or even
md.update(toHash.getBytes(ENCODING));
md.update(salt.getBytes(ENCODING));
byte[] bytes = md.digest();
This question already has answers here:
convert password encryption from java to php
(4 answers)
Closed 7 years ago.
I have JAVA AES encryption logic
private static byte[] getMD5(String input) {
try {
byte[] bytesOfMessage = input.getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
return md.digest(bytesOfMessage);
} catch (Exception e) {
}
return null;
}
What will be the php equivalent of this function?
I have used md5($string) in php but the output is different in both the cases.
In the code that you have posted you get the byte array of the md5 hash. PHP's md5() function returns the md5 hash as a hex.
So, if you want to get the md5 hash as string in java you can like this:
private static String getMD5(String input) {
try {
byte[] bytesOfMessage = input.getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
// byte array of md5 hash
byte[] md5 = md.digest(bytesOfMessage);
// we convert bytes to hex as php's md5() would do
StringBuffer stringBuffer = new StringBuffer();
for (int i = 0; i < md5.length; i++) {
stringBuffer.append(Integer.toString((md5[i] & 0xff) + 0x100, 16).substring(1));
}
return stringBuffer.toString();
} catch (Exception e) {
}
return null;
}
From PHP you can get the row md5 binary by doing md5('some string', true). See md5() function documentation about it.
To get the byte array you can do unpack('c*', md5('some string',true)). See unpack() function and the possible formats for more info.
I have a SQL table with usernames and passwords. The passwords are encoded using MessageDigest's digest() method. If I encode a password - let's say "abcdef12" - with MessageDigest's digest() method and then convert it to hexadecimal values, the String is different than if I do the same using PHP's SHA1-method. I'd expect these values to be exactly the same though.
Code that is used to encode the passwords:
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] passbyte;
passbyte = "abcdef12".getBytes("UTF-8");
passbyte = md.digest(passbyte);
The conversion of the String to hexadecimal is done using this method:
public static String convertStringToHex(String str) {
char[] chars = str.toCharArray();
StringBuffer hex = new StringBuffer();
for (int i = 0; i < chars.length; i++) {
hex.append(Integer.toHexString((int) chars[i]));
}
return hex.toString();
}
Password: abcdef12
Here's the password as returned by a lot of SHA1-hash online generators and PHP SHA1()-function: d253e3bd69ce1e7ce6074345fd5faa1a3c2e89ef
Here's the password as encoded by MessageDigest: d253e3bd69ce1e7ce674345fd5faa1a3c2e2030ef
Am I forgetting something?
Igor.
Edit: I've found someone with a similar problem: C# SHA-1 vs. PHP SHA-1...Different Results? . The solution was to change encodings.. but I can't change encodings on the server-side since the passwords in that SQL-table are not created by my application.
I use client-side SHA1-encoding using a JavaScript SHA1-class (more precisely: a Google Web Toolkit-class). It works and encodes the string as expected, but apparently using ASCII characters?..
I have the same digest as PHP with my Java SHA-1 hashing function:
public static String computeSha1OfString(final String message)
throws UnsupportedOperationException, NullPointerException {
try {
return computeSha1OfByteArray(message.getBytes(("UTF-8")));
} catch (UnsupportedEncodingException ex) {
throw new UnsupportedOperationException(ex);
}
}
private static String computeSha1OfByteArray(final byte[] message)
throws UnsupportedOperationException {
try {
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.update(message);
byte[] res = md.digest();
return toHexString(res);
} catch (NoSuchAlgorithmException ex) {
throw new UnsupportedOperationException(ex);
}
}
I've added to my unit tests:
String sha1Hash = StringHelper.computeSha1OfString("abcdef12");
assertEquals("d253e3bd69ce1e7ce6074345fd5faa1a3c2e89ef", sha1Hash);
Full source code for the class is on github.
Try this - it is working for me:
MessageDigest md = MessageDigest.getInstance(algorithm);
md.update(original.getBytes());
byte[] digest = md.digest();
StringBuffer sb = new StringBuffer();
for (byte b : digest) {
sb.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
Regards,
Konki
It has nothing to do with the encodings. The output would be entirely different.
For starters, your function convertStringToHex() doesn't output leading zeros, that is, 07 becomes just 7.
The rest (changing 89 to 2030) is also likely to have something to do with that function. Try looking at the value of passbyte after passbyte = md.digest(passbyte);.
Or try this:
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.update(clearPassword.getBytes("UTF-8"));
return new BigInteger(1 ,md.digest()).toString(16));
Cheers Roy