A House subcommittee has passed the Global Online Freedom Act (GOFA), which would require disclosure from companies about their human rights practices and limit the export of technologies that “serve the primary purpose of” facilitating government surveillance or censorship to countries designated as “Internet-restricting.”
Astronaut endorses destroying the moon!
The best exchange on the IAmA:
Ghostshirts it’s been a dream for a long time now, do you think that we’ll actually be able to blow up the moon in our lifetime?
RonGaran I truly believe that we can accomplish anything we set our minds on. We only need the will to do it
Hmmm
“This rather embarrassing issue was pointed out to the committee, the fact that there were three votes too many, and that these three votes determined the outcome. When this was done, along with formally requesting a re-vote, that re-vote on the points in question was denied.”
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:
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.
One of the more limiting issues of writing client side script in the browser is the same origin limitations of XMLHttpRequest. The latest version of all browsers support a subset of CORS to allow servers to opt-in particular resources for cross-domain access. Since IE8 there's XDomainRequest and in all other browsers (including IE10) there's XHR L2's cross-origin request features. But the vast majority of resources out on the web do not opt-in using CORS headers and so client side only web apps like a podcast player or a feed reader aren't doable.
One hack-y way around this I've found is to use YQL as a CORS proxy. YQL applies the CORS header to all its responses and among its features it allows a caller to request an arbitrary XML, HTML, or JSON resource. So my network helper script first attempts to access a URI directly using XDomainRequest if that exists and XMLHttpRequest otherwise. If that fails it then tries to use XDR or XHR to access the URI via YQL. I wrap my URIs in the following manner, where type is either "html", "xml", or "json":
yqlRequest = function(uri, method, type, onComplete, onError) {
var yqlUri = "http://query.yahooapis.com/v1/public/yql?q=" +
encodeURIComponent("SELECT * FROM " + type + ' where url="' + encodeURIComponent(uri) + '"');
if (type == "html") {
yqlUri += encodeURIComponent(" and xpath='/*'");
}
else if (type == "json") {
yqlUri += "&callback=&format=json";
}
...
As a professional URI aficionado I deal with various levels of ignorance on URI percent-encoding (aka URI encoding, or URL escaping).
Getting into the more subtle levels of URI percent-encoding ignorance, folks try to apply their knowledge of percent-encoding to URIs as a whole producing the concepts escaped URIs and unescaped URIs. However there are no such things - URIs themselves aren't percent-encoded or decoded but rather contain characters that are percent-encoded or decoded. Applying percent-encoding or decoding to a URI as a whole produces a new and non-equivalent URI.
Instead of lingering on the incorrect concepts we'll just cover the correct ones: there's raw unencoded data, non-normal form URIs and normal form URIs. For example:
In the above (A) is not an 'encoded URI' but rather a non-normal form URI. The characters of 'the' and 'path' are percent-encoded but as unreserved characters specific in the RFC should not be encoded. In the normal form of the URI (B) the characters are decoded. But (B) is not a 'decoded URI' -- it still has an encoded '?' in it because that's a reserved character which by the RFC holds different meaning when appearing decoded versus encoded. Specifically in this case, it appears encoded which means it is data -- a literal '?' that appears as part of the path segment. This is as opposed to the decoded '?' that appears in the URI which is not part of the path but rather the delimiter to the query.
Usually when developers talk about decoding the URI what they really want is the raw data from the URI. The raw decoded data is (C) above. The only thing to note beyond what's covered already is that to obtain the decoded data one must parse the URI before percent decoding all percent-encoded octets.
Of course the exception here is when a URI is the raw data. In this case you must percent-encode the URI to have it appear in another URI. More on percent-encoding while constructing URIs later.
As a professional URI aficionado I deal with various levels of ignorance on URI percent-encoding (aka URI encoding, or URL escaping).
Worse than the lame blog comments hating on percent-encoding is the shipping code which can do actual damage. In one very large project I won't name, I've fixed code that decodes all percent-encoded octets in a URI in order to get rid of pesky percents before calling ShellExecute. An unnamed developer with similar intent but clearly much craftier did the same thing in a loop until the string's length stopped changing. As it turns out percent-encoding serves a purpose and can't just be removed arbitrarily.
Percent-encoding exists so that one can represent data in a URI that would otherwise not be allowed or would be interpretted as a delimiter instead of data. For example, the space character (U+0020) is not allowed in a URI and so must be percent-encoded in order to appear in a URI:
http://example.com/the%20path/
http://example.com/the path/
For an additional example, the question mark delimits the path from the query. If one wanted the question mark to appear as part of the path rather than delimit the path from the query, it must be percent-encoded:
http://example.com/foo%3Fbar
http://example.com/foo?bar
/foo" from the query "bar". And in the first, the querstion mark is percent-encoded and so
the path is "/foo%3Fbar".
As a professional URI aficionado I deal with various levels of ignorance on URI percent-encoding (aka URI encoding, or URL escaping). The basest ignorance is with respect to the mere existence of percent-encoding. Percents in URIs are special: they always represent the start of a percent-encoded octet. That is to say, a percent is always followed by two hex digits that represents a value between 0 and 255 and doesn't show up in a URI otherwise.
The IPv6 textual syntax for scoped addresses uses the '%' to delimit the zone ID from the rest of the address. When it came time to define how to represent scoped IPv6 addresses in URIs there were two camps: Folks who wanted to use the IPv6 format as is in the URI, and those who wanted to encode or replace the '%' with a different character. The resulting thread was more lively than what shows up on the IETF URI discussion mailing list. Ultimately we went with a percent-encoded '%' which means the percent maintains its special status and singular purpose.
FTA: “Nick Bilton put the FAA’s claims regarding Kindles and airline avionics to the test. The result? They emit less EM interference than planes are required by law to withstand.” Much less, apparently.
“One in three people in Switzerland download unauthorized music, movies and games from the Internet and since last year the government has been wondering what to do about it. … The overall conclusion of the study is that the current copyright law, under which downloading copyrighted material for personal use is permitted, doesn’t have to change.” Wow, that sounds like almost reasonable and understandable copyright law.
A bug came up the other day involving markup containing <input type="image" src="http://example.com/.... I knew that "image" was a valid input type but it wasn't until that moment
that I realized I didn't know what it did. Looking it up I found that it displays the specified image and when the user clicks on the image, the form is submitted with an additional two name
value pairs: the x and y positions of the point at which the user clicked the image.
Take for example the following HTML:
<form action="http://example.com/">
<input type="image" name="foo" src="http://deletethis.net/dave/images/davebefore.jpg">
</form>http://example.com/?foo.x=145&foo.y=124.
This seemed like an incredibly specific feature to be built directly into the language when this could instead be done with javascript. I looked a bit further and saw that its been in HTML since at least HTML2, which of course makes much more sense. Javascript barely existed at that point and sending off the user's click location in a form may have been the only way to do something interesting with that action.
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