Showing posts with label random. Show all posts
Showing posts with label random. Show all posts
Monday, December 03, 2007
Bellsouth DNS goes belly up...
Oh wow. It seems like all of Bellsouth’s DNS for DSL customers is out. I switched mine to OpenDNS: 208.67.222.222. It cleared up my issues.
Monday, November 12, 2007
postmortem and ontime...
People who run WinDBG, or any debugger for that matter, as a postmortem debugger will notice alot of crashes most people won't. Flash9d everybody... 
Atst glance it looks like an unexploitable double free, but I could be wrong...
Monday, September 10, 2007
Past...Present...Future...
So I am done with my month long project and although parts of it will be public later this week, all I can say is its a 3 part research project entitled "Past...Present...Future..."
UPDATE: The "Past" portion of the 3 paper arch was just published at Uninformed.
We have "Present" and "Future" looming...
Here is a pick of the home office I have been working from, this setup is mostly duplicated everywhere else I would work from, I thought you might just want to see what the fuss is about.
Now that the project is done I gotta get back on the blogging track: I gotta post my Blackhat Vegas writeup, publish my pwnie acceptance speech, and what we are working on next.
UPDATE: The "Past" portion of the 3 paper arch was just published at Uninformed.
We have "Present" and "Future" looming...
Here is a pick of the home office I have been working from, this setup is mostly duplicated everywhere else I would work from, I thought you might just want to see what the fuss is about.
Now that the project is done I gotta get back on the blogging track: I gotta post my Blackhat Vegas writeup, publish my pwnie acceptance speech, and what we are working on next.
Friday, July 27, 2007
Inverse Steganography
This story says that things on your computer that make it look like you are hiding stuff is itself incriminating. For example, if you have an encrypted file on your disk, it is evidence that you have something to hide, and therefore means you must be guilty of something.
As somebody who loves freedom, this really bugs me. I do a lot of strange things, and I don't like the idea that they might come back to frame me for crimes because no normal person would do them.
For example, I like foreign movies (here is the latest movie in French that I bought). I was in a Blockbuster video rental store. Since foreign movies are not popular, they had them back behind a corner. While I was back there looking at the movies, a kid comes wandering by and asks "What's back here?". After answering "Foreign films", the kid looks up at me like I'm a perrvert, runs back to his mother, and starts babbling something while pointing to me. I don't know what the kid said, but I felt guilty and embarrassed nonetheless.
On a more serious note, I like to shoot guns, but don't want to get arrested for a local convenience store robbery because shooting guns isn't "normal".
Encryption is one of these perversions. More and more laws are being passed to restrict encryption. Many years ago, the United Kingdom passed a law requiring people to give up their encryption keys to law enforcement. Having encrypted files that law enforcement cannot decrypt is a crime. While being interviewed on this (I think for The Register) I suggested that what virus writers should do is, among other things, drop encrypted files on people's systems. This creates a sort of "inverse steganography", where the existence of encrypted data does not itself prove that the user is trying to encrypt anything.
Even if virus writers don't include this sort of code in their viruses, you can certainly add such files to your system. I've included code below that can create pseudo-encrypted files on Windows (and of course you can use /dev/urand on other systems). This software works because, in theory, "random" data is indistinguishable with "encrypted" data.
Even though virus writers haven't littered our systems with random files, you can still take advantage of inverse steganography. First, create a DVD image of some files that you want to encrypt. Then run a raw AES encryption with a strong key over that DVD image. This gives you a 4-gig file that outsiders know is either (1) random data or (2) encrypted data, but they can't be sure which. Next, create another disk image full of porn. Now XOR (in One-Time-Pad fashion) the two disk images together. Now write two DVD's to disk, one containing the AES encrypted data, and the other containing the XORed porn. When law enforcement finds you with both disks, you claim that the AES disk is actually just a One-Time-Pad, that it contains random data and NOT encrypted data. Thus, law enforcement can't prove that you the One-Time-Pad is actually encrypted data or not.
As an activist, you should do this even if you don't want to hide any data of your own. If you are like me and believe that humans should have the Right to Encrypt their private data, then you should have such random files on your computer and randomized disks among your backups. The more individuals do this, the less power law enforcement will have to prosecute those who encrypt data. It's not a loud protest, but it's still an important silent protest.
The code below is for Windows using Microsoft's Crytographic services. I'm using RC4 here in a naïve manner, so there is a chance that a determined adversary can prove the resulting file is, or is not, produced by this program, but I doubt your local cops would have the resources to do so.
#include <stdio.h>
#include <windows.h>
#include <wincrypt.h>
void main(int argc, char *argv[])
{
HCRYPTPROV hCryptProv;
unsigned size;
FILE *fp;
if (argc < 3) {
printf("usage:\n polyrand <size> <file>\n");
return;
}
size = strtoul(argv[1],0,0);
fp = fopen(argv[2],"wb");
CryptAcquireContext(&hCryptProv,NULL,NULL,PROV_RSA_FULL,0);
while (size) {
char buf[1024];
unsigned len = sizeof(buf);
if (len > size) len = size;
CryptGenRandom(hCryptProv,len,buf);
if (fwrite(buf,1,len,fp) != len)
printf("write err\n");
size -= len;
}
}
As somebody who loves freedom, this really bugs me. I do a lot of strange things, and I don't like the idea that they might come back to frame me for crimes because no normal person would do them.
For example, I like foreign movies (here is the latest movie in French that I bought). I was in a Blockbuster video rental store. Since foreign movies are not popular, they had them back behind a corner. While I was back there looking at the movies, a kid comes wandering by and asks "What's back here?". After answering "Foreign films", the kid looks up at me like I'm a perrvert, runs back to his mother, and starts babbling something while pointing to me. I don't know what the kid said, but I felt guilty and embarrassed nonetheless.
On a more serious note, I like to shoot guns, but don't want to get arrested for a local convenience store robbery because shooting guns isn't "normal".
Encryption is one of these perversions. More and more laws are being passed to restrict encryption. Many years ago, the United Kingdom passed a law requiring people to give up their encryption keys to law enforcement. Having encrypted files that law enforcement cannot decrypt is a crime. While being interviewed on this (I think for The Register) I suggested that what virus writers should do is, among other things, drop encrypted files on people's systems. This creates a sort of "inverse steganography", where the existence of encrypted data does not itself prove that the user is trying to encrypt anything.
Even if virus writers don't include this sort of code in their viruses, you can certainly add such files to your system. I've included code below that can create pseudo-encrypted files on Windows (and of course you can use /dev/urand on other systems). This software works because, in theory, "random" data is indistinguishable with "encrypted" data.
Even though virus writers haven't littered our systems with random files, you can still take advantage of inverse steganography. First, create a DVD image of some files that you want to encrypt. Then run a raw AES encryption with a strong key over that DVD image. This gives you a 4-gig file that outsiders know is either (1) random data or (2) encrypted data, but they can't be sure which. Next, create another disk image full of porn. Now XOR (in One-Time-Pad fashion) the two disk images together. Now write two DVD's to disk, one containing the AES encrypted data, and the other containing the XORed porn. When law enforcement finds you with both disks, you claim that the AES disk is actually just a One-Time-Pad, that it contains random data and NOT encrypted data. Thus, law enforcement can't prove that you the One-Time-Pad is actually encrypted data or not.
As an activist, you should do this even if you don't want to hide any data of your own. If you are like me and believe that humans should have the Right to Encrypt their private data, then you should have such random files on your computer and randomized disks among your backups. The more individuals do this, the less power law enforcement will have to prosecute those who encrypt data. It's not a loud protest, but it's still an important silent protest.
The code below is for Windows using Microsoft's Crytographic services. I'm using RC4 here in a naïve manner, so there is a chance that a determined adversary can prove the resulting file is, or is not, produced by this program, but I doubt your local cops would have the resources to do so.
#include <stdio.h>
#include <windows.h>
#include <wincrypt.h>
void main(int argc, char *argv[])
{
HCRYPTPROV hCryptProv;
unsigned size;
FILE *fp;
if (argc < 3) {
printf("usage:\n polyrand <size> <file>\n");
return;
}
size = strtoul(argv[1],0,0);
fp = fopen(argv[2],"wb");
CryptAcquireContext(&hCryptProv,NULL,NULL,PROV_RSA_FULL,0);
while (size) {
char buf[1024];
unsigned len = sizeof(buf);
if (len > size) len = size;
CryptGenRandom(hCryptProv,len,buf);
if (fwrite(buf,1,len,fp) != len)
printf("write err\n");
size -= len;
}
}
Sunday, March 11, 2007
A round up of things...
If you have been asking how to get Metasploit on the N800, you can find instructions here.
Its clock change time. If you have a blackberry and its not displaying the right time, you might need this patch.
I am on a eWeek panel this week with Jon Ellch, HD Moore, and Joanna Rutkowska. That’s right, 4 of the top 5 hackers on 2006 according to eWeek. I guess Mark is busy.
We will be making a new version of Ferret available at Blackhat Europe, with some really cool new features!
I also saw the 300. It made 70 million this weekend. That’s almost unheard of for a R rated movie. It’s great to see that there are movies moving away from the mindset that you have to make a movie PG-13 to make any money.
Maybe I am jaded but I didn’t really find it all that violent. A lot of reviewers seemed shocked over the level of violence, but it was more comic book style stuff that hardcore gore that you would find in something like Saw or Hostel (neither of which i really liked). Here is a tip for aspiring filmmakers, if half you movie is in slow motion you should find a different way to build drama or suspense. Every time there was a huge action scene I thought the slow-mo killed all momentum, it was like watching a music video...for two hours.
Its clock change time. If you have a blackberry and its not displaying the right time, you might need this patch.
I am on a eWeek panel this week with Jon Ellch, HD Moore, and Joanna Rutkowska. That’s right, 4 of the top 5 hackers on 2006 according to eWeek. I guess Mark is busy.
We will be making a new version of Ferret available at Blackhat Europe, with some really cool new features!
I also saw the 300. It made 70 million this weekend. That’s almost unheard of for a R rated movie. It’s great to see that there are movies moving away from the mindset that you have to make a movie PG-13 to make any money.
Maybe I am jaded but I didn’t really find it all that violent. A lot of reviewers seemed shocked over the level of violence, but it was more comic book style stuff that hardcore gore that you would find in something like Saw or Hostel (neither of which i really liked). Here is a tip for aspiring filmmakers, if half you movie is in slow motion you should find a different way to build drama or suspense. Every time there was a huge action scene I thought the slow-mo killed all momentum, it was like watching a music video...for two hours.
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