costy's Mega Difficult JADE Crackme By COSTY
| Download mega_difficult_jade_crackme_by_COSTY.zip, 4 kb (password: crackmes.de) Browse contents of mega_difficult_jade_crackme_by_COSTY.zip You have to find the valid serial.
Difficulty: 3 - Getting harder | RatingVotes: 3 View profile of costy » |
Solutions
Solution by movzx, published 02. jul, 2008; download (3 kb), password: crackmes.de or browse.
movzx has rated this crackme as quite nice.
Discussion and comments
| costy Author 26. Jun 2008 | Strange... Probably I made an error while selecting the difficulty... It's higher then 4 (i think)... Or moderators changed it after evaluation the program... I don't know... |
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| costy Author 26. Jun 2008 | What do you think about it? :) |
| MACH4 26. Jun 2008 | Excuse me for asking but who is P.Jade? Is it a clue? |
| costy Author 26. Jun 2008 | Hello MACH4 P.Jade is a great friend. I dedicated my crackme to her and it's a clue ;-) |
| PrincessJade 26. Jun 2008 | that would be me :) |
| MACH4 27. Jun 2008 | Ok thanks for the clarification! think I know whats going on but I'm not very good at reversing vb.6 to find how the check is done. |
| DigitalAcid 27. Jun 2008 | I think I somehow know what costy (or the crackme) tries to do, but cannot find any valid stuff atm. The serial checking looks so weird =). |
| costy Author 27. Jun 2008 | Hello MACH4 and DigitalAcid... send me a private message and tell me what are you doing |
| MACH4 28. Jun 2008 | Ok I know how this CrackMe works! Just a few unknown details atm My vb6 debugging capabilities are not very good though, but I will try to make a keygen... |
| costy Author 29. Jun 2008 | keygen?? Only a serial is valid... And it doesn't change if you have a different computer... SORRY ABOUT ENGLISH |
| Xspider 29. Jun 2008 | is that mean a hardcoded serial ????????!!!! |
| costy Author 29. Jun 2008 | hardcoded?? The serial is stored in the data file in a really particular way. |
| costy Author 29. Jun 2008 | Little Help: remplace the ones in the data file with zeros. Then save it. Now open the exe and click Check without inserting a serial. The program will display the Good Boy message. Now you should understood someting... |
| MACH4 29. Jun 2008 | If I'm right then the serial is (almost) a fixed one but no, not hard coded in the sense you mean -) The check is the fascinating feature!!! But then again, I could be wrong of course! |
| costy Author 30. Jun 2008 | I think the only solution is making a program that "traslate" the information in the data file. |
| movzx 01. Jul 2008 | wew... tricky.. but solved.. wait for my tut.. :D |
| costy Author 01. Jul 2008 | OK So the solution is ready. I was ispired by "Imagine" crackme |
| obnoxious 02. Jul 2008 | nice trick costy n a really gr8 tut by movzx ;) |
| movzx 02. Jul 2008 | hurray.. approved! "After someone sends the solution i will say which crackme inspired me." so.. which one? |
| movzx 02. Jul 2008 | errrr... i mean.. where can i download the "imagine" crackme? |
| costy Author 02. Jul 2008 | image crackme is here http://bigspider.altervista.org/Crackmes/imagine.zip but it works only on win 9x Anyway... Good gob... i'm studying your solution. |
| MACH4 02. Jul 2008 | Nice one movzx, I had two problems. Had dumped the data file and in notepad and squashed the lines like you did, but my eye's couldn't see the p jade message! The other thing I was stuck on was the GetPixel was visited twice. once x = 1 and the second visit y = 1, but the oposite inputs was always out of bounds so returning false or FFFFFFFFh on every time. Anyway, my vb6 debugging knowledge is quite poor! You don't mention anywhere in your solution, where your inputted number is checked in the algo, only the check between file content and get pixel? Am I missing something? |
| movzx 02. Jul 2008 | costy : thx :D MACH4 : if the GetPixel returns 0xFFFFFFFFh, means it the pixel is outside of the current clipping region. This because you overlap the main window of this crackme while you debugging and this crackme is paused by breakpoint. so the current pixel queried is not the TextBox' pixel, but probably your OllyDbg's current pixel at current point. "where your inputted number is checked in the algo, only the check between file content and get pixel?" the check between file content and get pixel is the check for inputted number. you see.. the algo scans for black and white pixel inside the TextBox. the font color is black, and the background (the TextBox color) is white. |
| MACH4 02. Jul 2008 | @movzx, Thanks for the explanation! I realise this now but I'm still surprised that GetPixel(hdc,1,1) actually gets the center pixel of each char in the textbox! ( whichI imagine is what is happening so that center of 0 is white and center of 1 is black) I'll have to work this one out with asm... |
| movzx 02. Jul 2008 | @MACH4, the GetPixel is inside the inner loop, and the x and y of GetPixel is from the loop index. |
| MACH4 02. Jul 2008 | @movzx, It would be ideal if this forum allowed uploading diagrams. My brain is saying that this loop won't work, but obviously it is! lol. Once I've sorted this out with an explanation, I'll pm you and costy with what I've found! |
| costy Author 03. Jul 2008 | MACH4 I sended the source to you... examine it. |
| MACH4 03. Jul 2008 | Hi costy, Yes the penny has finally dropped, I fully understand every detail now! after playing with it all last night. I had never seen such a method used before so my brain was telling me this is not right, when all the time it was! Thanks for being patient with me and many tnks for the source. Also tnks to movzx, who hit the nail right on the head! I've used his type of double loop before for scanning images, I had never even thought about the same principle being used to scan text in a textbox! Really excellent Crackme and very innovative! MACH4 |
| costy Author 03. Jul 2008 | It's not a new crackme. It's inspired by http://bigspider.altervista.org/Crackmes/imagine.zip. But mine is a bit different. imagine crackme works only on 9x that's the problem. |
| Xspider 03. Jul 2008 | yep it was a c0ol own good job mate ;) |
| costy Author 04. Jul 2008 | I liked a lot that crackme. So I decided to make another crackme very similar. |
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