I had to explain to her what six hours of sex felt like the next day. Red bull and viagra is a great combination, right up until you wake up the next day.
Im using and IP Camera at home and I have the footage being sent to an online file storage service as well as my handheld device through the internet. If the wifi router at home is turned off or somehow malfunctions and is no longer working, will I still be able to view the footage from my handhe...
if I change it from java.util.ArrayList to com.blah.TempFileWrapper and then TempFileWrapper has destructor logic that kills the file, then it would be an arbitrary file deletion bug
so if someone overrides finalise() to include logic that performs an action, e.g. delete a file, I might be able to construct an object that does that.
@lynks I think this would be good advice for @DavidFreitag, too... ;-)
@Polynomial to the best of my knowledge (and I did check this once, but memory is faulty), the serialization can only include data, no code. So it would not be possible to override finalize (or any other method) from serialization.
@AviD he wants to convince the target to deserialise it to something like a TemporaryFile that when finalize() is called, it will kill the TemporaryFile on disk. He then sticks the relevant path/guesses and inode/whatever and the file is his to delete.
@AviD let's say you've got a class called TempFile and that class has a property called Path, and in finalise() there's some code that deletes the file at path
@Polynomial depends I guess on whether the Java object serialisation communication whatever can authenticate data sent from somewhere else before decoding it into an object. I don't know anything about that, but I'm intrigued as to the answer.
if the cast is to something that may have worrisome finalise methods, then you're onto a winner. If not, I don't think you get to control what it deserialises to.
but usually, the target type of the cast is quite constrained, as far as I can tell.
but that's not to say that you can't do other... things with it ;-)
Yea, unless the server-side code is doing something really fancy (like reflection to determine the type of the serialised object to instantiate), then the casting seems to be fixed, and it's simply down to whether or not the person who implemented decided to have a cast to, for example, TemporaryFile (or similar)
another thing to note is that it's unlikely that anything important actually gets done in a finalise method, as they're not guaranteed to be called (the Object's space on the heap could be freed without running finalise() in a panic state, e.g. OOM recovery)
@Tinned_Tuna I think the question is - what if the whole purpose of the code is to pass a TemporaryFile object from one server to another. So the receiving server does cast to a TemporaryFile. Then said TemporaryFile executes a delete on a file - which is referred to by one of its member variables. Can you the attacker send the receiving server an object with an arbitrary value in that member, and therefore get it to delete whatever you like?
heh, oh wow. I just blindly added a pem file that was linked to on a random wordpress site to my server's trusted signing certificates. i shouldnt be allowed near a keyboard today.
@Tinned_Tuna @Polynomial @lynks I didn't follow the entire transcript, but you usually only serialize javabeans (Classes with getters and setters only). Not sure what sort of exploits come up with for that...
My friend is interviewing applicants for some web dev position (mainly JS stuff). He came up with the following exercise as a first level filter.
Try it! (Without posting in the console)
var a = 1;
var b = 1;
var c = 1;
var f = (function(){
a++;
var b = 0;
return true;
c++;
})();
console.log(a);
console.log(b);
console.log(c);
console.log(f);
Now here's the fun part. Nobody go the 4/4 correctly.
Also, although it's bad practice, if there is a return statement within the finally block, it will trump any other return from the regular block. That is, the following block would return false:
try { return true; } finally { return false; }
Same thing with throwing exceptions from the finally...
dammit, trying to export my gpg key as pkcs12, I have installed gpgsm as a utility that claims to be able to do this, however that utility for some reason has a separate key database to gpg and I can't figure out how to transfer my keys accross
@lynks Ah okay. well, I have a rasberry pi on which I can play, and that's scheduled in for later this week so I'll let you know more when I've had a go with it.
If I understood the basic of password hashing and storing, what we need are:
a "strong" salt
a "real" random salt
a unique salt per password
a hashing function with a high CPU cost
We hash the passwords using 1, 2, 3 and 4 using PHP crypt() and CRYPT_BLOWFISH with a "medium" cost.
We have a ...
@TerryChia Regarding your concern about how wimpy your musical tastes are...yes I listen to NIN and MetalTech and Grunge. I also love me some Mumford and Sons, Regina Spector, Ben Folds Five, and The Bloody Tinth.
Each of my objects has a constructor that accepts a DataColumnCollection and a DataRow. That way i can just execute the query and pipe the rows into constructors with a foreach loop.
I mean, i could be making one separate function to accomplish what each one of these Linq statements is doing, but then i'd have a gazillion functions. So i figured I'd use generics.
@TerryChia Grunge is a style from the 90s that is best defined by Nirvana or Pearl Jam. The Bloody Tinth is a band one of my friends is the violinist for that does Scottish/Irish folk songs (no piper). The others are big and popular enough that you can find then probably on the YouTubes
Also, although it's bad practice, if there is a return statement within the finally block, it will trump any other return from the regular block. That is, the following block would return false:
try { return true; } finally { return false; }
Same thing with throwing exceptions from the finally...
If I understood the basic of password hashing and storing, what we need are:
a "strong" salt
a "real" random salt
a unique salt per password
a hashing function with a high CPU cost
We hash the passwords using 1, 2, 3 and 4 using PHP crypt() and CRYPT_BLOWFISH with a "medium" cost.
We have a ...
