Posssible Privacy bug in Facebook?

 

Today I was browsing through list of friends of one of my friends (Friend_A). I found a profile of another person (Person_A). I wanted to view his pictures but his privacy settings didn’t allow viewing his albums/pictures. I couldn’t see Photos tab on profile page.

Later my friend (Friend_A) sent a link to (Person_A)’s picture on facebook and I was able to view it using that link. I was able to go through his albums completely without any issue.

I sent the same link to my another friend and he was able to view all pictures too even though he was not even 2nd level link to that person.

Is this possibly a bug in Facebook?

Replacing SMS on a Phone using Kannel SMS Gateway

What is Replace Message?

The 3GPP (ETSI) standard for GSM communication specifies a way to replace an existing message on a mobile phone by sending another message. I had a requirement to use this functionality with Kannel connected to an SMS GW that communicates over SS7/MAP.

Using Kannel to Replace Message

Sending a self destruct or replaceable message is pretty easy with Kannel as long as your SMSC supports it.

Send first SMS with pid=65
http://SERVER:PORT/cgi-bin/sendsms?from=55512345&username=me&password=mypass&
to=5551233&text=original+msg&pid=65

Send second SMS with pid=65

http://SERVER:PORT/cgi-bin/sendsms?from=55512345&username=me&password=mypass&
to=5551233&text=msg+replaced&pid=65

 

Quest for correct PID value

The documentation of Kannel doesn’t provide any information about the method at all. It however mentions the field PID that can be set while sending SMS. Looking at some forums related to NowSMS gateway, it appeared that PID can be used to send such SMS.

The next issue was to find out what exact value to provide as NowSMS GW allows a value of between 41--47 in decimal. This doesn’t work with Kannel.

3G TS 23.040 V3.2.0 (1999-10) on page 52-53 states this:

9.2.3.9 TP-Protocol-Identifier (TP-PID)
The TP-Protocol-Identifier parameter serves the purposes indicated in subclause 3.2.3. It consists of one octet, and the
bits in the octet are used as follows:
.
.
.
In the case where bit 7 = 0, bit 6 = 1, bits 5..0 are used as defined below
5 .. . .0
000000 Short Message Type 0
000001 Replace Short Message Type 1
000010 Replace Short Message Type 2
000011 Replace Short Message Type 3
000100 Replace Short Message Type 4
000101 Replace Short Message Type 5
000110 Replace Short Message Type 6
000111 Replace Short Message Type 7

Here is explanation of Replace Short Message from standard

The Replace Short Message feature is optional for the ME and the SIM but if implemented it shall be performed as
described here.
For MT short messages, on receipt of a short message from the SC, the MS shall check to see if the associated Protocol
Identifier contains a Replace Short Message Type code.
If such a code is present, then the MS will check the originating address and replace any existing stored message having
the same Protocol Identifier code and originating address with the new short message and other parameter values. If
there is no message to be replaced, the MS shall store the message in the normal way. The MS may also check the SC
address as well as the Originating Address. However, in a network which has multiple SCs, it is possible for a Replace
Message type for a SM to be sent via different SCs and so it is recommended that the SC address should not be checked
by the MS unless the application specifically requires such a check.

According to this 01000001 or in decimal 65 would give me Replace Short Message Type 1 and it can go upto 71.
I have tested this on Samsung, Nokia, HTC and iPhone. Seems to work fine on all of these.

MP3 to Audio Cassette Player

I always thought that whenever someone buys a car sound system, it should allow connecting of mp3 players as input device. The car I got doesn’t have that type of sound system and I didn’t want to buy a new system for that.
Yesterday, I found out that there exists a car cassette adapter that allows you to connect your mp3 player to a sound system which only supports audio cassettes or audio CDs with no external input source. Rare in modern world but most builtin systems are like that in smaller cars in Pakistan.

In Karachi, Pakistan, it can be bought for 250 PKR (2.5 Euros). The cassette has an audio cable to connect to your favorite mp3 player and of course has no tape in it. Its head does the magic of playing music by faking as a real cassette with rolling magnetic tape over it.
Here are pictures of the adapter I bought.

Thailand, not so nice after all

I recently got opportunity to go to Thailand and stay in Bangkok for a month. Actually, I am writing this entry from Bangkok.

Thailand is considered a very good tourist place but I find it hard to believe that Thai people really care about tourists. Here is why

Worst home internet ever

Thailand has probably the worst internet in one of modern countries. I am not myself from a very modern country (Pakistan) but still we get much better connection and more bandwidth (international) than Thailand. Our lag in Pakistan with servers around the world is much lower than Thailand. I mostly have to do remote management of servers in Europe and ABC Islands.
Thailand internet service providers (ISPs) mostly give you packages on ADSL from 128Kbps to 2Mbps. In reality the bandwidth is really different. When they promise 1Mbps you only get 256K  for international traffic and 1Mbps is applicable for traffic within Thailand. 256K or even 512K is pretty low in modern world specially when you have to pay for 1Mbps connection, 650 baht (20 USD) for first 6 months and 1000 baht (30 USD) after first 6 months. My SSH sessions are really painful to work on. The connection after midnight gets much better.

Over 95% Cheating Taxi drivers

I have had some experience with taxi drivers in different countries including China (Guangzhou, Shenzhen) but I have not seen such cheating taxi drivers ever.  The drivers will always take you the long way. When you are new in city, you will not notice that as you will not recognise different streets and the area where you are residing.  After 2-3 times of going out you will notice that you will be on the road where your residence is but driver will take left/right turn and then will circle around the area of your residence before taking you to your residence. The idea is simply to make more money of course.  This is not rare and I won’t be exaggerating to say that this happens 95% of the time. I have tried shouting at driver to take left or right when I saw the road to my residence but Mr Driver would either show a blank face pretending to not understand even the basic hand gestures or will try to explain in 1 to 2 words that there is more traffic this way. This is really bad and discouraging for tourists indeed.

Language Barrier

This is one of the biggest issues in Thailand. Just like China, very few people speak English and even a lot of sign-boards, instructions, maps and ingredients (note: halal and kosher food seekers) are in Thai. People even in shops don’t speak much English and use of calculator is important while negotiating for price. I know this can be interesting but for most part this is frustrating as when you really need to go somewhere and nobody can explain proper directions.
Thai websites are mostly in Thai only. Even big companies like AIS (Mobile/Internet company) have English sections but when clicked half of items in flash remain in Thai. A lot of websites only put Under Construction for their English version of website. Even the 404 pages are in Thai. Happens a lot with buddybb.

FilesToBeDeleted issue while installing update on Windows Mobile

I just got stuck with the problem where an update of my software on windows mobile which contains a com dll gets wrong (Default) registry entry in InproceServer32’s default key.
The key was something like

HKEY_CLASSES_ROOT\CLSID\{6777246F-2FAC-4376-BAB6-FF81EDFD3439}\InprocServer32
and value being inserted by CAB was
\Windows\FilesToBeDeleted\TMP0004.tmp

This similar issue was experienced by someone else here in this post
but no solution was posted in replies.

Anyway, one good and complicated solution is to write your own installer code like this one

The solution I used was much easier. In my CAB inf file I inserted the reg key with the value that it really should have, like this

[RegKeys]
"HKCR","CLSID\{6777246F-2FAC-4376-BAB6-FF81EDFD3439}\InprocServer32","","0x00000000","\Windows\MyDll.dll"

This solved the problem. After installation/updation the right DLL value was inserted and new DLL started to work as usual.