C# Discussion Boards - CodeProject

17-Feb-10 1:35

1) Try here[^]
2) Don't post your email to any forum unless you really like spam!

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

Re: net use

hammerstein0517-Feb-10 1:36

17-Feb-10 1:36

That's an awesome link Griff! Saved.. Smile | :)

Re: net use

hammerstein0517-Feb-10 1:35

17-Feb-10 1:35

I'll be as helpful as I can,

www.google.com

type in the box

"net use" .NET

There's some results on there that point you in the right direction.

C++ to CSharp

Xmen Real 17-Feb-10 1:11

17-Feb-10 1:11

I found a code for calculating CRC, but it was in C++

unsigned int CRC32(char* text)
{
	size_t textLen = strlen(text);
	int i = 0;
	unsigned int retHash = 0;
	if(text[0] == '"')
		i = 1;
	for(i;i<textLen;i++)
	{
		char ctext = textLen[i];
		if(ctext == '"')
			break;
		if(ctext - 65 > 25)
		{
			if(ctext == '\\')
				ctext = '/';
		}
		else ctext += 32;
		retHash = (1025 * (retHash + ctext) >> 6) ^ 1025 * (retHash + ctext);
	}
	return 32769 * (9 * retHash ^ (9 * retHash >> 11));
}

public static uint CRCRC(string text)
{
    uint retHash = 0;


    for (int a = 0; a < text.Length; a++)
    {
        char ctext = text[a];
        if (ctext == '"')
            break;
        if (ctext - 65 > 25)
        {
            if (ctext == '\\')
                ctext = '/';
        }
        else
            ctext = (char)(ctext + 32);
        retHash = (1025 * ((retHash + ctext) >> 6)) ^ 1025 * (retHash + ctext);
    }

    return 32769 * (9 * retHash ^ (9 * (retHash >> 11)));
}

so I converted it manually to C# but the result is not as expected. May be I did something wrong in converting...

TVMU^P[[IGIOQHG^JSH`A#@`RFJ\c^JPL>;"[,*/|+&WLEZGc`AFXc!L
%^]*IRXD#@GKCQ`R\^SF_WcHbORY87֦ʻ6ϣN8ȤBcRAV\Z^&SU~%CSWQ@#2
W_AD`EPABIKRDFVS)EVLQK)JKQUFK[M`UKs*$GwU#QDXBER@CBN%
R0~53%eYrd8mt^7Z6]iTF+(EWfJ9zaK-iTV.C\y<pjxsg-b$f4ia>

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128 bit encrypted signature, crack if you can

Covean17-Feb-10 1:28

Covean

17-Feb-10 1:28

The problem is maybe that char in C++ is an ASCII char (1 byte) and the char in C# is unicode (2 bytes).

Now if you look at the ctext += 32; statement.
The results will differ in C++ and C# for values above 223:

C++: 225 + 32 = 257 -> cast to char = 2
C#: 225 + 32 = 257 -> cast to char = 257!

Hope that helps.

Greetings
Covean

hammerstein0517-Feb-10 1:29

17-Feb-10 1:29

Your method is not a copy of the C++ code. Read over the two, understand the logic and you'll see the issues in the listings.

To be a little more accurate, I normally start by writing each line from the original, finding the language equivalent. If I meet something that doesn't have an equivalent, then I work to understand what it does so I can imitate it. When I've written the code, I then go back to refactor it or improve on it.

OriginalGriff17-Feb-10 1:32

Re: C++ to CSharp [modified]

17-Feb-10 1:32

Try using:

byte[] bytes = System.Text.Encoding.ASCII.GetBytes(text);

and then use bytes[a] instead of text[a]

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

Xmen Real 17-Feb-10 1:36

17-Feb-10 1:36

public static uint CRCRC(string text)
{
    uint retHash = 0;
    int a = 0;
    byte[] bytes = System.Text.Encoding.ASCII.GetBytes(text);

    if (bytes[0] == 34)
        a = 1;

    for (; a < bytes.Length; a++)
    {
        byte val = bytes[a];
        if (val == 34)
            break;
        if (val - 65 > 25)
        {
            if (val == 92)
                val = 47;
        }
        else
            val += 32;
        retHash = (1025 * (retHash + val) >> 6) ^ 1025 * (retHash + val);
    }
    return 32769 * (9 * retHash ^ (9 * retHash >> 11));
}

not working Frown | :(

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128 bit encrypted signature, crack if you can

modified on Wednesday, February 17, 2010 8:20 AM

hammerstein0517-Feb-10 1:41

17-Feb-10 1:41

In the original, the code is using textLen, not text.

OriginalGriff17-Feb-10 1:42

Re: C++ to CSharp [modified]

17-Feb-10 1:42

When you say "not working" what is not working? Remember, I can't see your screen, just what you tell me.

Check your logic - I notice that your loop is different from the C++ version which misses the first char if the string starts with '"' - yours ends the loop when it meets the first '"'. And please, don't use "magic numbers" - they make code really difficult to follow and maintain.

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

Xmen Real 17-Feb-10 1:49

17-Feb-10 1:49

not working mean, it suppose to return D18AA035 for B5_CUT2_1 but its returning 334A644A

OriginalGriff wrote:
Check your logic - I notice that your loop is different from the C++ version which misses the first char if the string starts with '"' - yours ends the loop when it meets the first '"'.

I modified the code

OriginalGriff wrote:
And please, don't use "magic numbers" - they make code really difficult to follow and maintain.

where ??

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128 bit encrypted signature, crack if you can

modified on Wednesday, February 17, 2010 8:16 AM

OriginalGriff17-Feb-10 3:11

17-Feb-10 3:11

Xmen W.K. wrote:
OriginalGriff wrote:
And please, don't use "magic numbers" - they make code really difficult to follow and maintain.
where ??

public static uint CRCRC(string text)
 {
     uint retHash = 0;
     int a = 0;
     byte[] bytes = System.Text.Encoding.ASCII.GetBytes(text);

     if (bytes[0] == 34)
         a = 1;

     for (; a < bytes.Length; a++)
     {
         byte val = bytes[a];
         if (val == 34)
             break;
         if (val - 65 > 25)
         {
             if (val == 92)
                 val = 47;
         }
         else
             val += 32;
         retHash = (1025 * (retHash + val) >> 6) ^ 1025 * (retHash + val);
     }
     return 32769 * (9 * retHash ^ (9 * retHash >> 11));
 }

34, 65, 25, 92, 47, 32 - these are all "magic numbers". Wiki - see Unnamed numerical constants here.[^] So called because they are necessary to the code but there is no explanation as to what the hell they are or do!
Looking at the original C++ code there is also a magic number 32769 - why? Does this have anything to do with the length of an int?
I am not convinced that the original code actually works (or even compiles): what is textLen[i] doing? textLen is a size_t (which is an unsigned int) not an array.

Try this[^] - I don't know that it works, I haven't tried it, but it is at least written in C# and looks like a CRC32 algorithm!

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

Xmen Real 17-Feb-10 3:17

17-Feb-10 3:17

That code is for specific CRC...I dunno why the author did that...I just got the code from a site that says its for that purpose(I need) so I simply tried to convert it to C# but I thought I may did something wrong. Thats why I asked here.

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128 bit encrypted signature, crack if you can

OriginalGriff17-Feb-10 3:32

17-Feb-10 3:32

If you have to use this specific code for a specific purpose then the original author is naughty to call it CRC32 if it isn't. The best way to proceed if you have to use this code and no other is to compile the C++ code into a managed DLL and include that assembly in your C# code - then it will only generate the wrong results if the original code is wrong as well!

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

Xmen Real 17-Feb-10 15:46

Re: C++ to CSharp [modified]

17-Feb-10 15:46

yupp I thought of that...but now I got the bug in the written code (C++). So all working fine now.

Btw, I can see somebody voted you 1. It wasn't me Frown | :(

Anyway, thanks for your time buddy. Have a nice day Wink | ;)

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128 bit encrypted signature, crack if you can

OriginalGriff17-Feb-10 22:11

17-Feb-10 22:11

Xmen W.K. wrote:
So all working fine now

Glad to hear it!

Xmen W.K. wrote:
Btw, I can see somebody voted you 1. It wasn't me

Didn't think it was - it's just an idiot ~~you~~ who thinks he's clever - I'm not bothered! Laugh | :laugh:

[edit]Typo as shown[/edit]

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

modified on Thursday, February 18, 2010 8:27 AM

Xmen Real 18-Feb-10 2:16

18-Feb-10 2:16

OriginalGriff wrote:
you thinks he's clever

what made you think like that

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128 bit encrypted signature, crack if you can

OriginalGriff18-Feb-10 2:30

18-Feb-10 2:30

Sorry about that! Typing error caused by insufficient coffee! Was intended to read "who thinks he's clever" - fixed now. Blush | :O

You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace

C/C++ (I dont see a huge difference between them, and the 'benefits' of C++ are questionable, who needs inheritance when you have copy and paste) - fat_boy

Xmen Real 18-Feb-10 2:33

18-Feb-10 2:33

hehe

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128 bit encrypted signature, crack if you can

Richard MacCutchan17-Feb-10 3:13

Richard MacCutchan

17-Feb-10 3:13

In your first sample the line

char ctext = textLen[i];

will produce bogus results. I think you mean to select the next character in the text string, the above instruction will pluck some random value from memory.

txtspeak is the realm of 9 year old children, not developers. Christian Graus