From: smcv Date: Thu, 14 May 2015 09:49:45 +0000 (-0400) Subject: proposal for making emailauth not force username == email address X-Git-Tag: 3.20150610~65^2~4 X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/commitdiff_plain/42b3b1f63abbaa17b4ea0780a643642f3e7ba72e proposal for making emailauth not force username == email address --- diff --git a/doc/todo/separate_authentication_from_authorization.mdwn b/doc/todo/separate_authentication_from_authorization.mdwn new file mode 100644 index 000000000..b4a3604ea --- /dev/null +++ b/doc/todo/separate_authentication_from_authorization.mdwn @@ -0,0 +1,92 @@ +[[plugins/openid]] and the new [[plugins/emailauth]] both assume that +the user's authentication identity (how they log in) is suitable as +an authorization identity (who they are when they have logged in). In +particular, the OpenID or email address goes into the git history. + +Relatedly, I'm not sure I'd be comfortable with enabling [[plugins/emailauth]] +on my own sites while it writes users' email addresses into the git history: +non-technical people (and many technical people for that matter) get +possessive about who can know their email address. The usual expectation for +email addresses on websites seems to be that they will be used by the site +owner (and maybe their outsourced service providers), but not available +to random third parties. The principle of least astonishment would suggest +that we should do the same here. + +(The expectation of privacy for direct git commits is rather different: +I think we can expect direct git committers to know that they +should either set a plausible non-email-address in their git identity, +like I used to use my OpenID, or have good spam filtering.) + +If we present email-based users in the "web UI" using only the local-part +of their address, we also have a potentially confusing situation where +`chris@example.com` and `chris@other.example.net` both contribute to a wiki: +if I'm reading the code right, they'd both be presented as `chris`, with no +way to change that other than using a different email address? + +Here is a sketch of a different account model that would address that: + +* An account has a username, e.g. `smcv`. It normally matches some regexp that + includes neither @ nor / (to rule out collisions with email addresses + and OpenIDs). + + * We currently allow qr{-[:alnum:]+/.:_} by default, so passwordauth + accounts can in principle collide with OpenIDs. That would probably be + worth fixing (for new account creation) anyway - I don't think we want + users with / in their names, which would make their user-page into a + subpage? + +* If passwordauth is enabled, accounts may have a password. Users can + authenticate to an account that has a password by entering that password. + The username is always the account name (because there's little reason + to do anything else). + +* If httpauth is enabled, anyone who can authenticate to the web server + automatically gets access to the account of the same name in the wiki. + (Or we could consider having a configurable map + { web-server-level username => wiki account } but the default would be + an identity mapping.) + +* If OpenID is enabled, accounts may have an OpenID. + The owner of that OpenID can log in, and gets logged-in to that account. + Either reusing the same OpenID for multiple accounts is not allowed, or + if the same OpenID is attached to more than one account the user can choose + (as an extra step). Optionally, more than one OpenID could be allowed. + +* If emailauth is enabled, accounts may have an email address. + Users can authenticate to an account that has an email + address (and is not a grandfathered OpenID) by using the token challenge. + (passwordauth accounts could already do a password-reset, so this is not + any less secure.) + +* Creating an account from an email address (maybe also OpenID?) has a new + step: choosing a username, with some text about "this name will appear + in recentchanges and in the wiki's history". The default would be the + local-part (user) from the email address. + +* Grandfathered OpenID support: every existing account that looks like an + OpenID has that OpenID associated with it, and it cannot be changed or + removed. The displayed form is openiduser(). + +* Grandfathered emailauth support, if required (but it might not be required + if we implement this model before the next ikiwiki release): every existing + account that looks like an email address has that email address associated + with it, and it cannot be changed or removed. The displayed form is + emailuser() but we should maybe change that to output something more + like `smcv@…`. + +* Hypothetically, an account could also have a https client certificate + for a new client-certificate plugin, or a Google account for a new OAuth2 + plugin, or whatever, and all of the above applies equally. + +* Unlike the current OpenID support, if the user's authentication provider + goes away (or if Google stops doing OAuth2 and moves on to the next big + thing), they can associate a different authentication identity with + their existing wiki account, and continue. + +This is basically the same model that Mozilla Persona encourages, +except using emailauth ourselves instead of outsourcing (the equivalent +of) that step to Mozilla. + +Thoughts? + +--[[smcv]]