Captcha solution using ASP3 & JS (source included)

Few years ago, I was looking for a simple way to embed a captcha solution on one of my sites (that was hosted on a shared IIS web-server). I looked all over for a captcha solution that won’t require installing an external DLL or connecting to a remote captcha server that will slow down the process (such as reCaptcha).

Back then I was coding in ASP3, so I decided to write my own class to do the job, and I named it “Captchavator”.

I’ve planned to release it to the public… but never did (I just forgot about it).

Last night, while I was browsing my HDD, I stumbled upon the Captchavator folder and the decided it’s time to make a move

You might say that ASP 3 is obsolete… and I’ll say “true, true…”, but since there are still many old sites out there, I think that even even if one person will find this useful, then it was worth releasing…

So what’s so special about this solution?

• It requires your web-server to support ASP 3, Javascript and nothing more
• Does not require installing any com/activex object on the server
• Does not require storing images on the server
• Developers can generate their own captcha characters using the included “painter” tool
• Does not use any database to operate
• Can be used with any shared hosting IIS web server

How can you use it?

The process is very simple and involves 4 simple steps…

Step 1 – Include the captcha class in your ASP page.

Step 2 – Create an instance of the Captchavatorobject

Set objCaptcha = New Captchavator

Step 3 – Generate a new captcha (pass the length of the requested captcha, in the following example, I’ve asked for a 6 chars long captcha).

objCaptcha.CreateCaptcha(6)

Step 4 – Print the captcha

objCaptcha.Print()

To validate the captcha, following these steps:

Step 1 – Include the captcha class in your ASP page.

Step 2 – Create an instance of the Captchavatorobject

Set objCaptcha = New Captchavator

Step 3 – Check if the passed POST/GET parameter matches the captcha

objCaptcha.Validate( Request(“txt1″) ) ‘will return true if validated successfully!

What’s included in the archive?

captcha.asp - This is the main Captchavator class

captcha_painter.asp - Use this file to generate your own captcha characters. Please note the painter only works with Internet Explorer (I’m too lazy to fix it to work with FF).

demo.asp - Demonstration of the complete process

I sure hope you’ll find this useful….

Try an online demo:  http://www.isralet.com/files/captcha/demo.asp

Download the Captchavator archive from here:
http://www.isralet.com/files/captcha/Captchavator v1.2 – ASP 3 Captcha.rar

Feel free to ask any questions by leaving a comment below.

המלצה על שרת זול ואמין לאירוח אתר חדש

המלצה על שרת בחו”ל זול ואמין לאירוח אתר חדש

לאחרונה התחלתי לעבוד עם חברה בחו”ל, בשם Host Monster,המספקת שרותי אחסון ואירוח מצויינים. מחיר חבילת אירוח בסיסית היא 5.95$ לחודש והיא כוללת כל מה שרק אפשר לחלום עליו, ובמחיר שווה לכל נפש.

בחבילה הבסיסית כלולים:

• דומיין לבחירתך עם סיומת .COM
• נפח אחסון בלתי מוגבל (אני כרגע מאחסן בשרת שלי קרוב ל-200 גיגה, למעשה אני מנצל את השרת גם כגיבוי אונליין).
• תעבורה בלתי מוגבלת (ספקים רבים מגבילים את נפח התעבורה, כאן לא מגבילים).
• קישור למספר בלתי מוגבל של דומיינים ללא תוספת תשלום!
• מספר בלתי מוגבל של חשבונות דואר (כולל תמיכה בPOP)
• שרתי UNIX
• קישור למסד נתונים מסוג MYSQL ללא תוספת תשלום
• תמיכה טלפונית – 24 שעות ביממה.

עד כה התרשמתי לטובה מהזמינות ומקצב התקשורת עם השרתים (שאגב, ממוקמים בארה”ב).
בנוגע לשירות לקוחות / תמיכה, ניתן לקבל שירות בטלפון או במייל. אך קיימת דרך נוחה (וזולה יותר) – באמצעות צ’ט אונליין עם נציג (הגישה היא דרך הדף הראשי באתר החברה). זוהי דרך נוחה, חסכונית ויעילה לפתרון בעיות ולקבלת עזרה באופן המהיר ביותר).

עד היום התנסתי במספר חברות אירוח שרתים אך עושה רושם שב- Host Monster התמורה ביחס למחיר היא הגבוהה ביותר.

אגב, ניתן גם לבטל את העסקה תוך 30 יום ולקבל החזר כספי ללא צורך במתן הסבר כלשהו, כך שאפשר לנסות ואם לא מתאים אז לבטל. אז, אין מה להפסיד…

כתובות נלוות:
www.hostmonster.com

Enabling Concurrent Remote Desktop Sessions on Windows XP SP3 – Patched file included

If you have multiple users on your Windows XP machine, you might have heard it is possible to patch the terminal services service, to support multiple concurrent remote desktop connection (via RDP) to your computer.

Around the time Windows XP SP1 was released, a patched version of the file termsrv.dll could be found on the Internet, replacing this file with your existing one enabled the concurrent remote sessions support.

Yesterday I upgraded to Windows XP SP3 (you may ask if it isn’t too early? maybe so, but since I’ve already been using the latest RC for some time now, I felt confident enough to apply this update on my home computer). Anyhow, after updating to SP3, I discovered my computer no longer supports concurrent remote sessions.

Short Googling returned few articles explaining how to patch the termsrv.dll to support concurrent sessions, so I pulled out my favorite HEX editor and with few clicks everything was up and running again.

To save so time for other users (and myself when upgrading more computers), I’ve packaged the updated termsrv.dll file with another file that will make the required changes to your registry. (see the included readme.txt file for further instructions).

Download the patched version: termsrv_sp3_patch.rar

Installation instructions
0. Go to C:\Windows\system32\dllcache and rename the termsrv.dll to termsrv.dll.bak
1. Go to \Windows\System32 folder and rename termsrv.dll to termsrv.dll.bak
2. Copy the new SP3 patched termsrv.dll to \Windows\System32 folder
3. Run the included registry patch “ts_concurrent_session_patch.reg” (by double clicking it), it will update the relevant registry values which are relevant to the concurrent sessions support.
3. Restart windows.

NOTE:
if you are currently using Terminal Services, you will need to start windows in safe mode before you can overwrite the existing termsrv.dll files.

Alon

UPDATE 7/June/08:
I’ve added a note to the installation instructions suggesting to  remove another copy of termsrv.dll that resides in the dllcache directory (Anthoney, thanks for the tip).

UPDATE 1/Aug/08:
The previous download link died. I uploaded the file to a new location.

My thoughts on Online Backup

Hi

Lately I’ve been doing some reading on online backups (aka. off-site backup) and it got me thinking…

Everybody knows the importance of backups, but every few weeks or so, I’m still getting this call from another poor soul that usually sounds like this: “oh no, my HDD just died.. what can I do to restore my data?”.

Thing is, most home users fail to backup their data regularly. I must admit that although I consider myself an advanced computer user (who is aware of how important it is to backup your data) I’m still not doing half than I should to make sure my data will be available to me when a catastrophe happens.

So yes, I’ve evolved in the last few years (after losing my laptop HDD and all the data that was on it) and started doing some daily backups between the computers in my home network (copying the data from one computer to another)… so now I feel pretty safe in the occasion of another HDD crash, but I’m still not doing any offline backups.

So what will happen if, god forbids, a burglar will visit me one day and take all my computers with all my precious data? in three words – I am fucked.

Of course the cheapest way to do backups (defiantly not the easiest) is to do it offline – Cassettes/CD’s/DVD’s or what have you. I really don’t know, maybe it’s just me being lazy, but even after losing all the important data I had on my dead laptop HDD I’m still failing to do offline backups and I believe most home users fail to backup their data this way as well.

Which brings me to the point of this email – Online Backup Services

We’ve all heard about them, some of us even experience some of them like xDrive, iBackup and others (I know I have ), but I never liked any of them for few reasons:

Why? few reasons:

1. Speed Speed Speed – if I started a backup session it would take ages until all the data is sent to their servers and it was hogging my bandwidth.
2. Privacy – I’ve never felt I can trust them with my precious data – how can I tell if someone is actually looking at my nude collection?
3. Laziness – I always had to remember to initiate the backup myself. Although most of the services do offer scheduling, it’s pretty worth-less when a backup takes approximately 34 hours

Today I came across another online backup service called Mozy (http://mozy.com/) – which promises unlimited online backup storage for ~55$/year.

To start backing up with Mozy, you need to create an account in their website and then you can download & install their backup software. You set an encryption password, choose the folders you wish to backup and Mozy will do everything else from there.

What I like about Mozy (and what actually differentiate their solution from what I’ve seen so far) is that their software is always running in the background checking which files have changed since the last backup (thus needed to be backed up again) and once your computer is idle, it will send these files to the remote server for backup. pretty neat, uh?

Being a true paranoid and all, I have one problem with Mozy (actually, the same problem applies to all the online backup solutions I know) – How can I be 100% sure nobody from Mozy is browsing my nude photo collection… Now seriously, although they offer a pretty impressive 448-bit Blowfish encryption and send the data over 128bit SSL connection, I still need to trust them not to send my private key to their server along with the data (allowing them to read all my data that is saved on their servers).
So if I was a normal person, I would probably trust them and use their product as is, but since I’m not, I’ve come up with a better solution – combining an external encryption software.

My new backup strategy is about to include another software – an external encryption utility named TrueCrypt (http://www.truecrypt.org/).

TrueCrypt is sort of an “on the fly encryption” utility. You predefine the folders to encrypt and TrueCrypt will create a new encrypted “virtual hard drive” that can be accessed like a normal drive. All the files on the “virtual HDD” will always be encrypted. TrueCrypt will keep encrypting transparently all files that are changing while I’m work with the computer.

To combine TrueCrypt & Mozy together, all I need to do is pointing Mozy’s backup software to the TrueCrypt “virtual hard drive”, and vwalla – I have a top notch secure backup service.

Few points to consider:

• The Mozy service costs ~55$/year (for unlimited backup storage) but you can try it for free (with 2GB of free storage). I myself believe it’s worth spending the 55$.
• Backup with Mozy can take long time (considering the slow upstream connections we have in Israel), but since Mozy is working when the computer is idle I don’t really care.
• I’m aware that are some much more sophisticated backup solutions out there but I was trying to focus on services that are more suitable for home users.
• Please consider, I’ve been using Mozy for only one day and still haven’t tried the combination with TrueCrypt, so before you trust all your precious data with these too, I can only suggest you test it for few days.

Alon

I’m so excited…

Welcome to my first blogging experience… I’m so excited (not)

I hope to put on paper (oh well, <DIV> elements) some interesting thoughts I may have on new technologies (mainly internet related) I come across during my daily cyber-cruises.

Hope you enjoy