Ahhh, FPGA, the ultimate toy and challenge for electronics hobbyists.
I've been learning about Verilog and VHDL (thanks J.Pereira) in my spare times.
Sometime ago, I've came across Robei - Visual Chip Design Software.
It's a nice piece of software for the FPGA newbie like me, it allows you to skip the code writing and draw directly your logic circuits, and then, study the generated code.
Robei, has a fair price and I strongly advise that you should buy it if needed.
Although, that night I had nothing special to do, and started to reverse Robei.
Found a simple way to subvert the registration system using the tools of the trade (OllyDbg, IDA, among others).
I've contacted the developer and explained the situation, also sent a patched version of the main executable.
He, being such a nice and comprehensive person, replied that it wasn't good enough, on big projects it would be spitting out errors because the lack of a valid registration.
So I fixed it and sent a new patch with the promise that wouldn't be distributed online.
Guosheng Wu, a big thank you for your understanding.
I did the crack/keygen for learning purposes only, code won't be distributed ever and I believe that you already fixed it in newer versions.
Wouldn't be nice if all the developers were understanding persons like Guosheng?
Saturday, May 10, 2014
I know it's flawed...
Some other day, after seeing Keypic, I've also found scr.im
scr.im is a service to protect e-mails beyond a captcha so that people can share e-mails on Twitter and avoid spammers.
Well... not really, captcha is flawed, javascript uses old tricks that don't protect anything anymore.
So, not only the e-mail is not protected, spammers can also download their entire database.
My bad, for not reading their FAQ first.
Admin knows it's flawed, however, this is to keep a minimal security and to keep it simple for users.
This is what happens when you're online late at night instead of sleeping.
We can't always win, right?!
scr.im is a service to protect e-mails beyond a captcha so that people can share e-mails on Twitter and avoid spammers.
Well... not really, captcha is flawed, javascript uses old tricks that don't protect anything anymore.
So, not only the e-mail is not protected, spammers can also download their entire database.
My bad, for not reading their FAQ first.
Admin knows it's flawed, however, this is to keep a minimal security and to keep it simple for users.
This is what happens when you're online late at night instead of sleeping.
We can't always win, right?!
Seems that I don't spam the right way?
Some night, I was browsing random stuff when I encountered someone talking about Keypic.
Keypic has a mission, to let CAPTCHAS disappear from the web.
I can relate to that, ReCAPTCHA is the most annoying thing that came across someone who just wants to post/reply something.
However, we do need something to stop those pesky spammers, but don't rely too much on Keypic to this.
I've broken it and made a PoC script. It was refused by the admins because, and check this:
"You don't spam in the regular way"
Oh, I'm so sorry, I didn't knew spammers had a "regular way".
I did however posted dozens of spam/links/text/pub on their demo blog. So, you go figure WTF is a regular way...
My brother did the same thing, we post all over the blog until the admins shut down the comments section.
I'm not aware of Keypic current state, like I've said before, I'm writing this way too long after writing the PoC script.
Hope that someday it works fine. It's a nice concept despite all the initial problems(?) or the admins arrogance to admit that the system has been defeated (on that day at least).
No, I won't post any kind of PoC code, you figure it out, it's really easy.
Keypic has a mission, to let CAPTCHAS disappear from the web.
I can relate to that, ReCAPTCHA is the most annoying thing that came across someone who just wants to post/reply something.
However, we do need something to stop those pesky spammers, but don't rely too much on Keypic to this.
I've broken it and made a PoC script. It was refused by the admins because, and check this:
"You don't spam in the regular way"
Oh, I'm so sorry, I didn't knew spammers had a "regular way".
I did however posted dozens of spam/links/text/pub on their demo blog. So, you go figure WTF is a regular way...
My brother did the same thing, we post all over the blog until the admins shut down the comments section.
I'm not aware of Keypic current state, like I've said before, I'm writing this way too long after writing the PoC script.
Hope that someday it works fine. It's a nice concept despite all the initial problems(?) or the admins arrogance to admit that the system has been defeated (on that day at least).
No, I won't post any kind of PoC code, you figure it out, it's really easy.
Sorry telemarketing people :)
Like thousands of people in Portugal, I have a landline phone because we don't have any option to have Internet access without forcing us to have a damn(dumb) phone.
It was everything running fine until I started to receive annoying calls. Those pesky ISP people trying to increase my monthly bill with stupid promotions that neither I need or like (Stupid M4O).
Also, I don't even use the number on that PSTN line, just VoIP.
Why you may ask? Because my provider offers free landline calls between 9pm and 9am, however, on VoIP (their own service) don't have this kind of limitation, go figure...
You may say: "Just disconnect the phone", well, ok, but this wouldn't be a smart option.
Having a spare Raspberry the work began.
All the calls incoming from the landline (SPA) will receive music on hold as long as the call lasts.
Add an exception to my own number, so that I can call home in case of emergency.
Add outbound route to direct all the outgoing calls via VoIP provider.
Add rule (with prefix) to allow outgoing via PSTN in case of VoIP failure.
Add rule to emergency calls (112); It will terminate any call in progress and route it through PSTN.
So, now I can eat, sleep and be with my family without having to answer dumb telemarketers.
It took about half an hour to accomplish this and another half to put everything in place.
Sorry MEO guys, but your promotions suck...
It was everything running fine until I started to receive annoying calls. Those pesky ISP people trying to increase my monthly bill with stupid promotions that neither I need or like (Stupid M4O).
Also, I don't even use the number on that PSTN line, just VoIP.
Why you may ask? Because my provider offers free landline calls between 9pm and 9am, however, on VoIP (their own service) don't have this kind of limitation, go figure...
You may say: "Just disconnect the phone", well, ok, but this wouldn't be a smart option.
Having a spare Raspberry the work began.
- Purchased a Linksys SPA-3102 and attached it to the landline
- Setup and configured FreePBX @ Raspberry Pi
- Setup inbound and outbound rules like this:
All the calls incoming from the landline (SPA) will receive music on hold as long as the call lasts.
Add an exception to my own number, so that I can call home in case of emergency.
Add outbound route to direct all the outgoing calls via VoIP provider.
Add rule (with prefix) to allow outgoing via PSTN in case of VoIP failure.
Add rule to emergency calls (112); It will terminate any call in progress and route it through PSTN.
So, now I can eat, sleep and be with my family without having to answer dumb telemarketers.
It took about half an hour to accomplish this and another half to put everything in place.
Sorry MEO guys, but your promotions suck...
Lazy me...
I had this blog for a while, it's still missing a lot of posts.
I'm kind of lazy to publish my "works" and findings, although I work every single day as a sysadmin, and at night reversing miscellaneous software and pentesting websites.
So, here it goes, some of my old and recent work. Please ignore the dates as they're not accurate.
Also ignore some English mistakes and grammar errors :)
Please note that this is private/personal work, it does not always reflect my employer point of view or values.
Thank you.
I'm kind of lazy to publish my "works" and findings, although I work every single day as a sysadmin, and at night reversing miscellaneous software and pentesting websites.
So, here it goes, some of my old and recent work. Please ignore the dates as they're not accurate.
Also ignore some English mistakes and grammar errors :)
Please note that this is private/personal work, it does not always reflect my employer point of view or values.
Thank you.
Wednesday, February 23, 2011
Outlook 2010 talking to Exchange 2000 via SMTP.
After some requests in my personal e-mail, I've decided to explain here the steps needed to make Outlook 2010 work with an SMTP Exchange 2000 server.
(Sorry my english, as is not my natural language)
The case goes back to January, when I needed to configure Outlook 2010 to work with the company's server that is based in a different country. This is a little important detail, as the foreign IT department wouldn't be any helpfull. The server was an Exchange 2000 but all the clients are working via SMTP and POP.
If you need to connect O2010 to Exchange 2000 using Exchange's protocol, please stop reading right here.
So, I knew that e-mails could be received, but by all the means, they just won't go out.
I grabbed a copy of Wireshark and started to analyse what's wrong in here.
Long story short:
...the server tells the client what authentication protocols it supports, however Outlook 2010 wants to use DIGEST-MD5.
This is the main difference between Outlook Express (which works great) and Outlook 2010:
And it stops right here, no auth, no e-mails to the outside world :)
So, if this is just a little glitch in the matrix, we'll fix it with a python script.
This script, is just a bad re-writen code of a transparent proxy, we're you can mess around with the messages sent between server<->client.
My biggest thanks go to:
Dirk Holtwick (INI reader)
Lobsang (Python Proxy) @ ActiveState
They sure saved me a lot of work by not re-inventing the wheel myself.
So this is the script:
(Update: Removed code, use github link instead)
https://github.com/yaba/SMTPProxy
(Sorry my english, as is not my natural language)
The case goes back to January, when I needed to configure Outlook 2010 to work with the company's server that is based in a different country. This is a little important detail, as the foreign IT department wouldn't be any helpfull. The server was an Exchange 2000 but all the clients are working via SMTP and POP.
If you need to connect O2010 to Exchange 2000 using Exchange's protocol, please stop reading right here.
So, I knew that e-mails could be received, but by all the means, they just won't go out.
I grabbed a copy of Wireshark and started to analyse what's wrong in here.
Long story short:
...the server tells the client what authentication protocols it supports, however Outlook 2010 wants to use DIGEST-MD5.
This is the main difference between Outlook Express (which works great) and Outlook 2010:
Outlook Express:
HELO machine
AUTH LOGIN
username base64 encoded
password base64 encoded
mails go through.
Outlook 2010:
HELO machine
AUTH DIGEST-MD5
response from server
Outlook sends just a *
AUTH LOGIN
password base64 encodedAnd it stops right here, no auth, no e-mails to the outside world :)
So, if this is just a little glitch in the matrix, we'll fix it with a python script.
This script, is just a bad re-writen code of a transparent proxy, we're you can mess around with the messages sent between server<->client.
My biggest thanks go to:
Dirk Holtwick (INI reader)
Lobsang (Python Proxy) @ ActiveState
They sure saved me a lot of work by not re-inventing the wheel myself.
So this is the script:
(Update: Removed code, use github link instead)
https://github.com/yaba/SMTPProxy
Sorry, some pieces are in Portuguese, but the code is self-explanatory.
In the config file, you have 2 sections, on srv2clt it processes all the messages from server to client and changes what is need to make Exchange 2000 work with Outlook 2010 (Auth strings)
The clt2srv isn't really needed, but, while I was at it, I thought this could come in handy sometime.
So... now, you have to run the script at localhost or any other server, and tell Outlook to use THAT server as the SMTP server, also, change the config.ini to meet your real SMTP server.
I've also added the port option, just in case.
My costumer uses only windows machines *sigh*, so I've converted python script to a Windows executable and used a tutorial (easy to find online) to make it work like a windows service.
If you have any questions or it doesn't work out for you, just send a e-mail or comment, I'll try to help as soon as possible.
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