404 page 2 - Dave's Blog

Kevin and Eileen's Photos of Our Wedding - Kevin, Dave and Matthew

2010 Jun 5, 3:54

Atlantis Aquarium Silver Fish

2010 Feb 28, 11:35

sequelguy posted a photo:

Bahama Beach Club Beach

2010 Feb 19, 12:03

sequelguy posted a photo:

ocean sky beach water sarah abaco bahama bahamabeachclub

Oceano Hotel

2010 Jan 31, 1:03

sequelguy posted a photo:

ca hotel halfmoonbay oceano

HD DVD / Randomness... : Why not use hashes for the Anti-Phishing Filter?

2009 Sep 30, 4:07The hashing part makes sense, but not the 'why no URL query' bit: "But because victim=12345 has already been visited they satisfy condition 2 and they get the 404 page fooling them into thinking the site has already been taken down. So query strings don't really work." You could implement the same thing in the path and even were that not the case there's no telling that removing the query would get you the same page. What's described here is a general method to circumvent the AP filter not an explaination as to why it avoids the query portion of the URL.

phishing technical web browser http url hash

The 'Is It UTF-8?' Quick and Dirty Test

2009 Mar 6, 5:16

I've found while debugging networking in IE its often useful to quickly tell if a string is encoded in UTF-8. You can check for the Byte Order Mark (EF BB BF in UTF-8) but, I rarely see the BOM on UTF-8 strings. Instead I apply a quick and dirty UTF-8 test that takes advantage of the well-formed UTF-8 restrictions.

Unlike other multibyte character encoding forms (see Windows supported character sets or IANA's list of character sets), for example Big5, where sticking together any two bytes is more likely than not to give a valid byte sequence, UTF-8 is more restrictive. And unlike other multibyte character encodings, UTF-8 bytes may be taken out of context and one can still know that its a single byte character, the starting byte of a three byte sequence, etc.

The full rules for well-formed UTF-8 are a little too complicated for me to commit to memory. Instead I've got my own simpler (this is the quick part) set of rules that will be mostly correct (this is the dirty part). For as many bytes in the string as you care to examine, check the most significant digit of the byte:

F:: This is byte 1 of a 4 byte encoded codepoint and must be followed by 3 trail bytes.
E:: This is byte 1 of a 3 byte encoded codepoint and must be followed by 2 trail bytes.
C..D:: This is byte 1 of a 2 byte encoded codepoint and must be followed by 1 trail byte.
8..B:: This is a trail byte.
0..7:: This is a single byte encoded codepoint.

The simpler rules can produce false positives in some cases: that is, they'll say a string is UTF-8 when in fact it might not be. But it won't produce false negatives. The following is table from the Unicode spec. that actually describes well-formed UTF-8.

Code Points	1st Byte	2nd Byte	3rd Byte	4th Byte
U+0000..U+007F	00..7F
U+0080..U+07FF	C2..DF	80..BF
U+0800..U+0FFF	E0	A0..BF	80..BF
U+1000..U+CFFF	E1..EC	80..BF	80..BF
U+D000..U+D7FF	ED	80..9F	80..BF
U+E000..U+FFFF	EE..EF	80..BF	80..BF
U+10000..U+3FFFF	F0	90..BF	80..BF	80..BF
U+40000..U+FFFFF	F1..F3	80..BF	80..BF	80..BF
U+100000..U+10FFFF	F4	80..8F	80..BF	80..BF

test technical unicode boring charset utf8 encoding

Subst Allows Non-Letter Drive Letters

2009 Mar 4, 2:39

I knew that the command line tool subst would create virtual drives that map to existing directories but I didn't know that subst lets you name the virtual drives with characters that aren't US-ASCII letters. For instance you can run 'subst 4: C:\windows' and then 'more 4:\win.ini' to dump C:\windows\win.ini. This also works for non-US-ASCII characters like, "Ｃ" (aka U+FF23, Fullwidth Latin Capital Letter C), which when displayed by cmd.exe via some best fit style character conversions looks just like the regular US-ASCII 'C'. None of Explorer, IE, or the common file dialogs allow the use of these odd virtual drives -- just cmd.exe, so I'm not sure how this would ever be useful but I thought it was odd and I wanted to share.

cli technical boring subst windows

Deutsches Museum

2008 Dec 17, 2:21

sequelguy posted a photo:

museum munich technology science deutschesmuseum germanymunich

Desert Botanical Garden Statue

2008 Jun 1, 11:38

sequelguy posted a photo:

arizona art nature statue scottsdale desertbotanicalgarden

Finally finished Baroque Cycle Novels

2008 May 2, 10:20

I've finally finished the Baroque Cycle, a historical fiction series set in the 17th and 18th centuries by Neal Stephenson whose work I always enjoy. There were often delays where I'd forget about the books until I had to take plane somewhere, or get discouraged reading about the character's thoughts on economics, or have difficulty finding the next volume, or become more engrossed in other books, projects or video games, and leave the Baroque Cycle books untouched for many months at a time. Consequently, my reading of this series has, I'm ashamed to say, spanned years. After finishing some books which I enjoy I end up hungry for just a bit more to read. For this series I don't need a bit more to read, I'm done with that, but I do want a badge or maybe a medal. Or barring that, college credit in European History and Macro Economics. I can recommend this book to anyone who has enjoyed Neal Stephenson's other work and has a few years of free time to kill.

history neal stephenson baroque cycle book nontechnical

ErrorZilla err ErrorSoft

2007 Aug 21, 4:04Seeing ErrorZilla I realized I could easily do a similar thing to the IE7 404 page using the same technique I used for the XML view and the feed view.

So that's what I did: I made a new 404 page for IE7. There's not much new here technically if you've read the previous blog entries to which I linked. My 404 page change adds links to the Internet Archive, the Coral Cache, and Whois Tool.

archive personal res cache resource ie7 technical browser whois 404 error extension

Missing Bee Roundup

2007 Apr 15, 4:06For the past several months I've seen various articles suggesting why bees are disappearing. At first I thought this was another crackpot's article that somehow made it onto digg.com. But they keep coming and sometimes from credible sources. After the article I saw tonight I thought I should go back and put together the various articles I've read on this topic. Bees may be disappearing due to pesticides, new organic pathogens, genetically modified crops, mobile phones, or climate change. Apparently, the US hasn't been keeping accurate counts of its bees so we don't know the extent of the situation. There's an interview with Maryann Frazier, M.S., of the Dept. of Etymology at Penn State and a congressional hearing on the matter.

I know this is all very serious and could signal the end of our ecosystem as we know it, but I can't help throwing in the following links as well. The bees could be hiding in this Florida couple's kitchen. Or perhaps they're laying low while being trained by the government to fight terrorism. Or they're hiding in extra dimensions that we mere humans can't perceive (I'm fairly certain that's what this article is suggesting. Really. Read it. Seriously. Its awesome.)

roundup personal bees nontechnical