standard - Dave's Blog


Let's Encrypt Update

2016 Nov 5, 8:59

Since I had last posted about using Let's Encrypt with NearlyFreeSpeech, NFS has changed their process for setting TLS info. Instead of putting the various files in /home/protected/ssl and submitting an assistance request, now there is a command to submit the certificate info and a webpage for submitting the certificate info.

The webpage is{username}/sites/{sitename}/add_tls and has a textbox for you to paste in all the cert info in PEM form into the textbox. The domain key, the domain certificate, and the Let's Encrypt intermediate cert must be pasted into the textbox and submitted.

Alternatively, that same info may be provided as standard input to nfsn -i set-tls

To renew my certificate with the updated NFS process I followed the commands from Andrei Damian-Fekete's script which depends on

python --account-key account.key --csr domain.csr --acme-dir /home/public/.well-known/acme-challenge/ > signed.crt
wget -O - > intermediate.pem
cat domain.key signed.crt intermediate.pem > chained.pem
nfsn -i set-tls < chained.pem
Because my certificate had already expired I needed to comment out the section in that validates the challenge file. The filenames in the above map to the following:
  • signed.crt is the Let's Encrypt provided certificate
  • account.key is the user private key registered with LE
  • domain.csr is the cert request
  • domain.key is the key for the domain cert
PermalinkCommentscertificate lets-encrypt

Let's Encrypt Setup

2016 Feb 4, 2:48

2016-Nov-5: Updated post on using Let's Encrypt with

I use for my webhosting for my personal website and I've just finished setting up TLS via Let's Encrypt. The process was slightly more complicated than what you'd like from Let's Encrypt. So for those interested in doing the same on, I've taken the following notes.

The standard Let's Encrypt client requires su/sudo access which is not available on's servers. Additionally NFSN's webserver doesn't have any Let's Encrypt plugins installed. So I used the Let's Encrypt Without Sudo client. I followed the instructions listed on the tool's page with the addition of providing the "--file-based" parameter to

One thing the script doesn't produce is the chain file. But this topic "Let's Encrypt - Quick HOWTO for NSFN" covers how to obtain that:

curl -o domain.chn

Now that you have all the required files, on your NFSN server make the directory /home/protected/ssl and copy your files into it. This is described in the NFSN topic provide certificates to NFSN. After copying the files and setting their permissions as described in the previous link you submit an assistance request. For me it was only 15 minutes later that everything was setup.

After enabling HTTPS I wanted to have all HTTP requests redirect to HTTPS. The normal Apache documentation on how to do this doesn't work on NFSN servers. Instead the NFSN FAQ describes it in "redirect http to https and HSTS". You use the X-Forwarded-Proto instead of the HTTPS variable because of how NFSN's virtual hosting is setup.

RewriteEngine on
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R=301]

Turning on HSTS is as simple as adding the HSTS HTTP header. However, the description in the above link didn't work because my site's NFSN realm isn't on the latest Apache yet. Instead I added the following to my .htaccess. After I'm comfortable with everything working well for a few days I'll start turning up the max-age to the recommended minimum value of 180 days.

Header set Strict-Transport-Security "max-age=3600;" 

Finally, to turn on CSP I started up Fiddler with my CSP Fiddler extension. It allows me to determine the most restrictive CSP rules I could apply and still have all resources on my page load. From there I found and removed inline script and some content loaded via http and otherwise continued tweaking my site and CSP rules.

After I was done I checked out my site on SSL Lab's SSL Test to see what I might have done wrong or needed improving. The first time I went through these steps I hadn't included the chain file which the SSL Test told me about. I was able to add that file to the same files I had already previously generated from the Let's Encrypt client and do another NFSN assistance request and 15 minutes later the SSL Test had upgraded me from 'B' to 'A'.

PermalinkCommentscertificate csp hsts https lets-encrypt

Retweet of 18F

2015 Mar 16, 9:48
Today the White House is proposing an HTTPS-only standard for the entire federal government:  Public comment welcome!

Retweet of stshank

2015 Mar 14, 10:42
Mobile developers flocked to iOS and Android, but @dontcallmeDOM says the Web is fighting back with new standards. 

location.hash and are bad and they should feel bad

2014 May 22, 9:25
The DOM location interface exposes the HTML document's URI parsed into its properties. However, it is ancient and has problems that bug me but otherwise rarely show up in the real world. Complaining about mostly theoretical issues is why blogging exists, so here goes:
  • The location object's search, hash, and protocol properties are all misnomers that lead to confusion about the correct terms:
    • The 'search' property returns the URI's query property. The query property isn't limited to containing search terms.
    • The 'hash' property returns the URI's fragment property. This one is just named after its delimiter. It should be called the fragment.
    • The 'protocol' property returns the URI's scheme property. A URI's scheme isn't necessarily a protocol. The http URI scheme of course uses the HTTP protocol, but the https URI scheme is the HTTP protocol over SSL/TLS - there is no HTTPS protocol. Similarly for something like mailto - there is no mailto wire protocol.
  • The 'hash' and 'search' location properties both return null in the case that their corresponding URI property doesn't exist or if its the empty string. A URI with no query property and a URI with an empty string query property that are otherwise the same, are not equal URIs and are allowed by HTTP to return different content. Similarly for the fragment. Unless the specific URI scheme defines otherwise, an empty query or hash isn't the same as no query or hash.
But like complaining about the number of minutes in an hour none of this can ever change without huge compat issues on the web. Accordingly I can only give my thanks to Anne van Kesteren and the awesome work on the URL standard moving towards a more sane (but still working practically within the constraints of compat) location object and URI parsing in the browser.


2013 Dec 17, 9:03

What is good and common of all JS promise designs collected as Promises/A+


An open standard for sound, interoperable JavaScript promises—by implementers, for implementers.

PermalinkCommentstechnical javascript

Indicating Details of Problems to Machines in HTTP

2012 Jul 3, 2:28

This specification defines a “Problem Detail” as an extensible way to carry machine-readable details of errors in a response, to avoid the need to invent new response formats.

PermalinkCommentstechnical http ietf standard

JSON Hypermedia API Language

2012 Jul 1, 1:52

The JSON Hypermedia API Language (HAL) is a standard which establishes conventions for expressing hypermedia controls, such as links, with JSON.

PermalinkCommentsjson uri url link technical standard ietf

So Listen Carefully To That Song Of The Modem | Best Of MetaFilter

2012 Jun 3, 12:43

A thread about the sounds dial-up modems used to make prompted member Devonian to recall being a fly on the wall during the development of modem speed standards

PermalinkCommentstechnical standards modem

Play Fez

2012 May 7, 3:30

I'm done playing Fez. The style is atmospheric retro nastalgia and on the surface the gameplay is standard 2D platformer with one interesting Flatland style game mechanic but dig deeper to find Myst style puzzles. Despite the following I thoroughly enjoyed the game and would recommend it to anyone intrigued by the previous. Five eighths through the game I ran into one of the game's infamous Fez save game breaking issues, but I enjoyed the game enough that I started over before any patches were released and had no further issues.

While playing the game I created some tools to help keep track of my Fez notes (spoilers) including a Pixelated Image Creator that makes it easy to generate data URIs for large, black and white pixelated images, and (spoilers) a Fez Transliteration Tool to help me translate the in-game writing system.

PermalinkCommentsvideo-game fez game xbox

"Additional Media Type Structured Syntax Suffixes" - Tony Hansen

2012 Apr 26, 3:15

This document defines several Structured Syntax Suffixes for use with media type registrations. In particular, it defines and registers the “+json”, “+ber”, “+der”, “+fastinfoset”, “+wbxml” and “+zip” Structured Syntax Suffixes, and updates the “+xml” Structured Syntax Suffix registration.

PermalinkCommentstechnical json mime ietf rfc standard

Alternate IPv4 Forms - URI Host Syntax Notes

2012 Mar 14, 4:30

By the URI RFC there is only one way to represent a particular IPv4 address in the host of a URI. This is the standard dotted decimal notation of four bytes in decimal with no leading zeroes delimited by periods. And no leading zeros are allowed which means there's only one textual representation of a particular IPv4 address.

However as discussed in the URI RFC, there are other forms of IPv4 addresses that although not officially allowed are generally accepted. Many implementations used inet_aton to parse the address from the URI which accepts more than just dotted decimal. Instead of dotted decimal, each dot delimited part can be in decimal, octal (if preceded by a '0') or hex (if preceded by '0x' or '0X'). And that's each section individually - they don't have to match. And there need not be 4 parts: there can be between 1 and 4 (inclusive). In case of less than 4, the last part in the string represents all of the left over bytes, not just one.

For example the following are all equivalent:
Standard dotted decimal form
Fewer parts
All of the above

The bread and butter of URI related security issues is when one part of the system disagrees with another about the interpretation of the URI. So this non-standard, non-normal form syntax has been been a great source of security issues in the past. Its mostly well known now (CreateUri normalizes these non-normal forms to dotted decimal), but occasionally a good tool for bypassing naive URI blocking systems.

PermalinkCommentsurl inet_aton uri technical host programming ipv4

"Forwarded HTTP Extension" - Andreas Petersson, Martin Nilsson

2012 Jan 27, 9:41PermalinkCommentstechnical http http-header proxy ietf standard

Obscuring Location

2011 Jul 1, 10:17"A method for obscuring location information is described. Both static and changing location information can be obscured. A single distance measure is input to the process; this parameter controls the precision of location information that can be extracted by a recipient."PermalinkCommentsgeoloc geolocation technical rfc standard reference

The Canonical Link Relation

2011 Jul 1, 10:15"This specification defines the canonical link relation -- an element which designates the preferred version of content/URI from a set of duplicate or near duplicate pages."PermalinkCommentslink uri url html rel technical standard rfc canonical

Use of the "X-" Prefix in Application Protocols

2011 Jul 1, 10:12" Historically, protocol designers and implementers distinguished
between "standard" and "non-standard" parameters by prefixing the
latter with the string "X-". On balance, this "X-" convention has
more costs than benefits, although it can be appropriate in certain
circumstances."PermalinkCommentsprefix technical standrad rfc uri url x-

clip.exe - Useful tool I didn't know shipped with Windows

2011 May 26, 11:00

When you run clip.exe, whatever comes into its standard input is put onto the clipboard. So when you need to move the result of something in your command window somewhere else you can pipe the result into clip.exe. Then you won't have to worry about the irritating way cmd.exe does block copy/pasting and you avoid having to manually fixup line breaks in wrapped lines. For instance, you can put the contents of a script into the clipboard with:

more cdo.cmd | clip

I've got a lot of stuff dumped in my bin folder that I sync across all my PCs so I didn't realize that clip.exe is a part of standard Windows installs.

Nice for avoiding the block copy in cmd.exe but I'd prefer to have the contents sort of tee'd into the clipboard and standard output. So TeeClip.ps1:

$input | tee -var teeclipout | clip;
PermalinkCommentspowershell clip tool clipboard cli technical windows tee

CSS Fonts Module Level 3

2011 May 10, 10:49Interesting standards disagreements showing up in specs: "Some implementers feel a same-origin restriction should be the default for all new resource types while others feel strongly that an opt-in strategy usuable for all resource types would be a better mechanism and that the default should always be to allow cross-origin linking for consistency with existing resource types (e.g. script, images). As such, this section should be considered at risk for removal if the consensus is to use an alternative mechanism."PermalinkCommentsreference web development font specification w3c css3

What are all the common undefined behaviour that a C++ programmer should know about? - Stack Overflow

2011 May 2, 7:33I recalled that the order of function/method parameter evaluation was not specified by C++ standard, but I didn't know the more general rule and the associated implications for the double check locking construct. Interesting.PermalinkCommentstechnical c++ programming

SRU: Search/Retrieval via URL -- SRU, CQL and ZeeRex (Standards, Library of Congress)

2011 Apr 18, 4:27"SRU is a standard XML-focused search protocol for Internet search queries, utilizing CQL (Contextual Query Language), a standard syntax for representing queries."PermalinkCommentsstandards search library metadata xml uri technical library-of-congress
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