5 ms·

The reason is because that's how mod_userdir has worked for a couple of decades or so. It was a way to easily allow unprivileged users to share content from th

The reason is because that's how mod_userdir has worked for a couple of decades or so. It was a way to easily allow unprivileged users to share content from their ~/public_html/ directory.

Alex3917 9y ago
Interesting. This makes sense from a technical perspective. Nevertheless, it's clearly associated with UGC content, and as far as I know there have never been any major sites that have hosted non-UGC content using this scheme. (E.g. there is no history of use for things like Amazon product pages or whatever.) And in school we were always taught that content coming from user pages on university systems shouldn't be cited as if it were academic content being published or endorsed by the university. I'm sure others were taught the same.
- p4lindromica 9y ago
  The reason this matters is the same origin policy, which tilde does not protect you from
  - Alex3917 9y ago
    That makes sense. I still think there is good reason to create a standard around this indicating UGC content within a subdomain though. For example: - Browsers might want to treat it differently for malware scanning purposes. - Content owners might want to treat it differently when filing automated DMCA complaints. - Search engines might want to treat it differently for ranking purposes.
    - cyphar 9y ago
      One of the biggest reasons why GitHub (for example) uses a separate subdomain is so that a persistent XSS exploit on their UGC domain cannot access HTTPOnly cookies or other information from their real domain. Impersonation is a bigger problem for a government, but it's also a security measure against how broken the current security model for things like cookies is.
      - Alex3917 9y ago
        I get why subdomains can be useful for preventing XSS and CORS issues, especially for non API-driven sites. The problem is that subdomains are used for all sorts of things, so just because something is on a subdomain doesn't signal that it's UGC content. Even if you hosted each person's content on its own subdomain, it would still be useful to have a standard way to signal that this content wasn't created by the organization who owns the domain. The benefit of the tilde is that, at least as far as I know, it has never been used for anything other than signaling that something is UGC content. (Even if that was a technological accident and not its original intent.)
        joombaga 9y ago
        > it would still be useful to have a standard way to signal that this content wasn't created by the organization who owns the domain. Do you think the assumption that the content was created by the organization who owns the domain should be default? Wouldn't it be better for the organization to provide a signature for the content it did create?
        Alex3917 9y ago
        > Do you think the assumption that the content was created by the organization who owns the domain should be default? Sure, and I think that is the current assumption. What's missing is a way to specify UGC content that wasn't created by the organization. > Wouldn't it be better for the organization to provide a signature for the content it did create? I don't think this would be viable for two reasons: - It would require people to do the work to opt in, without any obvious incentive for doing so. - No obvious way to different UGC content from javascript dependencies, fonts, ad trackers, etc. Whereas there are good use cases for allowing folks to mark content as being UGC. For example, let's say the game Draw Something wanted to let users upload their creations. So no security issues, since images are created through their own app, but they don't necessarily want everyone thinking that they're spending all day creating and uploading millions of dick drawings either.
        9y ago

The reason is because that's how mod_userdir has worked for a couple of decades or so. It was a way to easily allow unprivileged users to share content from their ~/public_html/ directory.

Alex3917 9y ago

Interesting. This makes sense from a technical perspective. Nevertheless, it's clearly associated with UGC content, and as far as I know there have never been any major sites that have hosted non-UGC content using this scheme. (E.g. there is no history of use for things like Amazon product pages or whatever.) And in school we were always taught that content coming from user pages on university systems shouldn't be cited as if it were academic content being published or endorsed by the university. I'm sure others were taught the same.

p4lindromica 9y ago
The reason this matters is the same origin policy, which tilde does not protect you from
- Alex3917 9y ago
  That makes sense. I still think there is good reason to create a standard around this indicating UGC content within a subdomain though. For example: - Browsers might want to treat it differently for malware scanning purposes. - Content owners might want to treat it differently when filing automated DMCA complaints. - Search engines might want to treat it differently for ranking purposes.
  - cyphar 9y ago
    One of the biggest reasons why GitHub (for example) uses a separate subdomain is so that a persistent XSS exploit on their UGC domain cannot access HTTPOnly cookies or other information from their real domain. Impersonation is a bigger problem for a government, but it's also a security measure against how broken the current security model for things like cookies is.
    - Alex3917 9y ago
      I get why subdomains can be useful for preventing XSS and CORS issues, especially for non API-driven sites. The problem is that subdomains are used for all sorts of things, so just because something is on a subdomain doesn't signal that it's UGC content. Even if you hosted each person's content on its own subdomain, it would still be useful to have a standard way to signal that this content wasn't created by the organization who owns the domain. The benefit of the tilde is that, at least as far as I know, it has never been used for anything other than signaling that something is UGC content. (Even if that was a technological accident and not its original intent.)
      - joombaga 9y ago
        > it would still be useful to have a standard way to signal that this content wasn't created by the organization who owns the domain. Do you think the assumption that the content was created by the organization who owns the domain should be default? Wouldn't it be better for the organization to provide a signature for the content it did create?
        Alex3917 9y ago
        > Do you think the assumption that the content was created by the organization who owns the domain should be default? Sure, and I think that is the current assumption. What's missing is a way to specify UGC content that wasn't created by the organization. > Wouldn't it be better for the organization to provide a signature for the content it did create? I don't think this would be viable for two reasons: - It would require people to do the work to opt in, without any obvious incentive for doing so. - No obvious way to different UGC content from javascript dependencies, fonts, ad trackers, etc. Whereas there are good use cases for allowing folks to mark content as being UGC. For example, let's say the game Draw Something wanted to let users upload their creations. So no security issues, since images are created through their own app, but they don't necessarily want everyone thinking that they're spending all day creating and uploading millions of dick drawings either.
        9y ago