From olli at lurza.secnetix.de Mon Dec 1 02:48:14 2008 From: olli at lurza.secnetix.de (Oliver Fromme) Date: Mon Dec 1 02:48:22 2008 Subject: using VPNs to cope with IP address changes In-Reply-To: <49330766.4010301@daleco.biz> Message-ID: <200812011047.mB1AlrgA044049@lurza.secnetix.de> Kevin Kinsey wrote: > Dan Langille wrote: > > Is this easier? > > > > http://dan.langille.org/wp-content/bot-check/bc-image.php?human=Wow83QpZ6AM= That one is trivial to read by simple OCR software. > And re: someone's comment (private to both of us) about machine reading, > I've no idea how good the botz are at that, so I'd not let my comments > affect your bot blocking unless you get more opinions on it. Or find > the botz can read it ;-) The "botz" are very good at it, according to a recent article in the German c't magazine. It is very non-trivial to create captchas difficult to OCR but still readable by humans on all kinds of different screens. And they create problems for visually-challenged people (that's why some sites offer a link to download the captcha text as mp3, but I doubt it is very convenient and encourages people to sign up). Basically, captchas are last-century technology. There are several other ways to prevent bots from signing up or leaving "comments" in blogs, guestbooks etc. The avove mentioned article enumerated quite a few ways to do that. One of the clever ones is to provide a form input field labeled "street address" or whatever, but make it invisible so humans don't fill it in. Bots tend to fill in _all_ fields (because many forms require you to fill in all fields), so your CGI software can easily recognize bots. A similar trick is to hide an input field within a HTML comment. Many bots ignore comment delimiters and fill in the fields anyway. Another trick is the opposite: Use a bit of javascript to create a form input field on the fly which is not present in the HTML text. Bots usually don't execute javascript, so they don't fill in that field. Advanced bot blocking includes creating random field names (dynamically) and using time stamps and cryptographic signatures, and accept every submission only within a limited amout of time (and only once). There are more things you can do, and of course you should combine several of these. It also depends on whether you want to defend against occasional visits of bots that spider the web, or against bots specifically targeted against your site. The latter is much more difficult, obviously. All of those defensive measures have the advantage that your users don't have to decipher captchas anymore. > I do appreciate what you do for the community at large, Dan. Seconded! Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Gesch?ftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht M?n- chen, HRB 125758, Gesch?ftsf?hrer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "Share your knowledge. It is a way to achieve immortality." -- The Dalai Lama From onlyjulien at gmail.com Thu Dec 18 09:18:14 2008 From: onlyjulien at gmail.com (=?GB2312?B?1cXSu7er?=) Date: Thu Dec 18 09:18:21 2008 Subject: Stop in /usr/ports/misc/compat3x.... Message-ID: <2dc52b0e0812180856w362de750hf3eccddb6d0a85d1@mail.gmail.com> I want to launch Openoffice.org3, then I was told to install jre before I install jre, i have to install compat3x then, it says: ===> compat3x-i386-5.0.20020925 is forbidden: "FreeBSD-SA-03:05.xdr, FreeBSD-SA-03:08.realpath - not fixed / no lib available". *** Error code 1 Stop in /usr/ports/misc/compat3x.... any one has any idea with this? (I've installed compat5x when I installed Nvidia-driver-96xx, is that why?) From des at des.no Thu Dec 18 10:05:00 2008 From: des at des.no (=?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?=) Date: Thu Dec 18 10:05:07 2008 Subject: Stop in /usr/ports/misc/compat3x.... In-Reply-To: <2dc52b0e0812180856w362de750hf3eccddb6d0a85d1@mail.gmail.com> (=?utf-8?B?IuW8oAnkuIDluIYiJ3M=?= message of "Fri, 19 Dec 2008 00:56:06 +0800") References: <2dc52b0e0812180856w362de750hf3eccddb6d0a85d1@mail.gmail.com> Message-ID: <86ocz9pe8r.fsf@ds4.des.no> "???" writes: > I want to launch Openoffice.org3, then I was told to install jre > before I install jre, i have to install compat3x How old is your ports tree, and which port did you try to install? DES -- Dag-Erling Sm?rgrav - des@des.no From onlyjulien at gmail.com Fri Dec 19 18:37:08 2008 From: onlyjulien at gmail.com (Only Julien) Date: Fri Dec 19 18:37:13 2008 Subject: Can't find the GDM user 'gdm'??? Message-ID: <2dc52b0e0812191837o248c6337y8cac07416292a6f0@mail.gmail.com> I've installed Gnome and added "gdm_enable="YES"" in /etc/rc.conf, then everytime system boots, it says: gdm-binary[939]: WARNING: gdm_config_parse: Can't find the GDM user 'gdm'. Aborting! gdm_config_parse: Can't find the GDM user 'gdm'. Aborting! Then GDM cannot correctly start.. Anyway, after I login, I still can start gnome by "startx"... But what's wrong with my GDM??? I've checked /ect/passwd and /ect/group, there's no gdm in them. So I added it manually simply copy from /etc/passwd.bak, and then reboot, the error remains the same... Talking about user, I realize something is wrong with adduser too... When I try to add a new user(no matter by "adduser" or "pw"), I failed everytime... And it says: pw: user 'onlyjulien' disappeared during update adduser: ERROR: There was an error adding user (onlyjulien). When I try to add user (onlyjulien) again, it says "pw: user 'onlyjulien' already exists". But if I try to login as "onlyjulien", it says login incorrect... I remember that, some errors occured when I install FreeBSD 7.0 release via CDs. There's something wrong with CD2, some packages hadn't been installed because some data lost... And I copied something to /home/root/, then the disk was full...But I didn't realise it. After this, I try to add new user, but I failed because of no more space left. Then I delected some files in /home/root/ to make some free space, and then adduser again, that was when I started to fail everytime... What is this all about??? How can I fix those problems?? From mitchell at wyatt672earp.force9.co.uk Sat Dec 20 11:24:54 2008 From: mitchell at wyatt672earp.force9.co.uk (Frank Mitchell) Date: Sat Dec 20 11:25:01 2008 Subject: File System Ext2 On DVD+RW Message-ID: <200812201849.45914.mitchell@wyatt672earp.force9.co.uk> Hi: Recently I noticed Sun Solaris used CDs with a UFS File System. So I decided to try UFS and Ext2 on Optical Disks. It should work on CD-RW, but I had spare DVD+RW disks, so I decided to get more ambitious. Note that DVDs use 2048-byte Sectors like CDs, but they're handled in Error-Correcting Blocks of 16. You can't expect DVD-RW to work, because DVD-RW only writes complete ECC Blocks. But DVD+RW (like DVD-RAM) can update individual Sectors. FreeBSD UFS1 wouldn't work this way. The FreeBSD Handbook gives instructions for DVD-RAM, and obviously DVD-RAM has a different layout. But OpenSUSE Linux seems okay with Ext2 on DVD+RW. I copied a large Subtree and checked the result using diff -qr. Does anybody have thoughts about this idea? Like: Any disadvantages which haven't occurred to me? Obviously if you're recording Personal Information on Removable Media it might be preferable to use a format which isn't readable under Windows. Faictz Ce Que Vouldras: Frank Mitchell From mitchell at wyatt672earp.force9.co.uk Sun Dec 21 09:59:40 2008 From: mitchell at wyatt672earp.force9.co.uk (Frank Mitchell) Date: Sun Dec 21 09:59:52 2008 Subject: Experiments With DVD+RW Message-ID: <200812211755.10039.mitchell@wyatt672earp.force9.co.uk> Hi Guys: I discovered the disadvantage of putting an Ext2 File System on DVD+RW: FreeBSD and NetBSD can't mount it, even though they're fine with Ext2 on a Hard Disk partition. Also alas, the Website of Robert Derman, http://www.dermancomputer.com, seems to have vanished, along with his useful free E-Book: "You Can Build Your Own Computer". Faictz Ce Que Vouldras: Frank Mitchell From bsd-unix at embarqmail.com Sun Dec 21 13:34:42 2008 From: bsd-unix at embarqmail.com (Randy Pratt) Date: Sun Dec 21 13:34:49 2008 Subject: Experiments With DVD+RW In-Reply-To: <200812211755.10039.mitchell@wyatt672earp.force9.co.uk> References: <200812211755.10039.mitchell@wyatt672earp.force9.co.uk> Message-ID: <20081221161440.4ed36e40.bsd-unix@embarqmail.com> On Sun, 21 Dec 2008 17:55:09 +0000 Frank Mitchell wrote: > Also alas, the Website of Robert Derman, http://www.dermancomputer.com, > seems to have vanished, along with his useful free E-Book: "You Can Build Your > Own Computer". I was able to find it thru an archive: http://web.archive.org/web/20070215141342/http://www.dermancomputer.com/ They also archived the book you're speaking of. HTH, Randy --