Encryption/Decryption of files

Subject: Encryption/Decryption of files Wed Dec 09, 2009 10:56 pm

I have wrote two simple scripts for encryption and decryption of files. Feel free to use them for the game!

scr_save_file(filename, string)

Code:: //argument0=filename
//arguemnt1=string that will be encrypted
{
var i, file, size;
file=file_bin_open(argument0, 1);
size=string_length(argument1);
for(i=1; i <= size; i += 1)
{
file_bin_write_byte(file, ord(string_char_at(argument1, i))^(((7*i+6)*i*i+94*i+238) mod 256));
}
file_bin_close(file);
}

scr_open_file(filename)

Code:: //This script decrypts the file argument0 and returns the result as a string
//Argument0=the file that will be decrypted
{
var str, file, j, i, char;
file=file_bin_open(argument0, 0);
str="";
j=file_bin_size(file);
for(i=1; i <= j; i += 1)
{
char=chr(file_bin_read_byte(file)^(((7*i+6)*i*i+94*i+238) mod 256));
str += char;
}
file_bin_close(file);
return str;
}

The numbers that here are 7, 6, 94 and 238 are arbitary, they can and should be changed so that we don't use the same key for all of our file formats.
It's important that the key in the saving scipt is exactly the same as the key in the opening script.

Subject: Re: Encryption/Decryption of files Wed Dec 09, 2009 11:11 pm

Thank you very much! Could the second script return the string, it would be easier that way.

Subject: Re: Encryption/Decryption of files Wed Dec 09, 2009 11:15 pm

Oh, I forgot to add that line...

Subject: Re: Encryption/Decryption of files Wed Dec 09, 2009 11:23 pm

wow!! thats coool
thx
-Bret

Subject: Re: Encryption/Decryption of files Thu Dec 10, 2009 4:18 am

Yeah, it is very cool. I can't say I've actually seen the script before to do this type of thing.

I will add this to the resource pack. Thanks Gullesnuffs! You're doing great!

Subject: Re: Encryption/Decryption of files Fri Dec 11, 2009 9:09 am

I tried putting this in teh game, and it told me it cannot find variable save_file.txt

What should I do to make it work correctly?
-Bret

Subject: Re: Encryption/Decryption of files Fri Dec 11, 2009 10:17 am

Well, maybe you used a function that required having that specific file created. Try making a text document in that name and see how it works. Just a suggestion...

Subject: Re: Encryption/Decryption of files Sat Dec 12, 2009 7:07 am

I tried that... how exactually do I put this in the game Gullesnuffs??
I'm rather retarded lately and i need step by step procedures, sadly : S
-Bret

Subject: Re: Encryption/Decryption of files Sat Dec 12, 2009 8:25 pm

If it says that it couldn't find the variable save_file.txt that is because that's not a variable =P
Probably, the error you're doing is that you write:

Code:: scr_save_file(save_file.txt, string(score));

Instead of:

Code:: scr_save_file("save_file.txt", string(score));

You need "" to make Game Maker understand that it's a string, not a variable.

Subject: Re: Encryption/Decryption of files Tue Dec 15, 2009 11:29 am

Could some one provide me with these 2 scripts except that it looks on the second line for information? I want to combine the text files into one main one. Thanks in advance.

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 10:18 am

Please?? I really need this if I want to finish the engine. I will attempt to find the functions if I don't get help by Friday (because that's the next time I'll be on the computer). The engine is coming great though. For the leveling, I am using arrays instead of variables.

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 10:53 am

ok what exactually do you need?? I'm confused...

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 7:27 pm

The exact same scripts except they save and load information from the second line of a document instead of the first line.

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 9:14 pm

but why? The data is saved on one line and it's up to your program what you use if it shows it as one or multi rows. Notepad shows everything on one line but Wordpad shows is on many lines.

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 9:51 pm

Oh so I encrypt every variable the same way, and it will do all of the work? And it will decrypt the right information? Or do I have to decrypt the information in the same order that I encrypted it...?

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 10:05 pm

If you need to save several variables, you can always create multiple files Razz

, if you don't want to do that, however, you'll probably need to have some kind of seperator between the different data, like this:

Code:: //This script decrypts the file argument0 and returns the value as a string
//Argument0=the file that will be decrypted
{
var str, file, j, i, char, k;
file=file_bin_open(argument0, 0);
str="";
j=file_bin_size(file);
k=0;
for(i=1; i <= j; i += 1)
{
char=chr(file_bin_read_byte(file)^(((7*i+6)*i*i+94*i+238) mod 256));
if(char == "|")
{
value[k]=str;
str="";
k += 1;
}
else
{
str += char;
}
}
file_bin_close(file);
}

And for saving just use

Code:: scr_save_file("filename.xxx", string(value[0]) + "|" + string(value[1]) + "|" + string(value[2]) + "|" + string(value[3]) + "|");

Subject: Re: Encryption/Decryption of files Thu Dec 17, 2009 10:08 pm

Thanks! It is currently saving to multiple files, but that's but that's why I needed this script! This is exactly what I was looking for, I don't think I wouldn't have been able to make this!

» Saving multiple encrypted files as one