3 commits

Author	SHA1	Message	Date
Mechiel Lukkien	0c800f3d7e	update to latest sherpats fixing typo in error message, handle absent dmarc "policy override" reason	2024-03-09 15:43:49 +01:00
Mechiel Lukkien	0f8bf2f220	replace http basic auth for web interfaces with session cookie & csrf-based auth ... the http basic auth we had was very simple to reason about, and to implement. but it has a major downside: there is no way to logout, browsers keep sending credentials. ideally, browsers themselves would show a button to stop sending credentials. a related downside: the http auth mechanism doesn't indicate for which server paths the credentials are. another downside: the original password is sent to the server with each request. though sending original passwords to web servers seems to be considered normal. our new approach uses session cookies, along with csrf values when we can. the sessions are server-side managed, automatically extended on each use. this makes it easy to invalidate sessions and keeps the frontend simpler (than with long- vs short-term sessions and refreshing). the cookies are httponly, samesite=strict, scoped to the path of the web interface. cookies are set "secure" when set over https. the cookie is set by a successful call to Login. a call to Logout invalidates a session. changing a password invalidates all sessions for a user, but keeps the session with which the password was changed alive. the csrf value is also random, and associated with the session cookie. the csrf must be sent as header for api calls, or as parameter for direct form posts (where we cannot set a custom header). rest-like calls made directly by the browser, e.g. for images, don't have a csrf protection. the csrf value is returned by the Login api call and stored in localstorage. api calls without credentials return code "user:noAuth", and with bad credentials return "user:badAuth". the api client recognizes this and triggers a login. after a login, all auth-failed api calls are automatically retried. only for "user:badAuth" is an error message displayed in the login form (e.g. session expired). in an ideal world, browsers would take care of most session management. a server would indicate authentication is needed (like http basic auth), and the browsers uses trusted ui to request credentials for the server & path. the browser could use safer mechanism than sending original passwords to the server, such as scram, along with a standard way to create sessions. for now, web developers have to do authentication themselves: from showing the login prompt, ensuring the right session/csrf cookies/localstorage/headers/etc are sent with each request. webauthn is a newer way to do authentication, perhaps we'll implement it in the future. though hardware tokens aren't an attractive option for many users, and it may be overkill as long as we still do old-fashioned authentication in smtp & imap where passwords can be sent to the server. for issue #58	2024-01-05 10:48:42 +01:00
Mechiel Lukkien	849b4ec9e9	add webmail ... it was far down on the roadmap, but implemented earlier, because it's interesting, and to help prepare for a jmap implementation. for jmap we need to implement more client-like functionality than with just imap. internal data structures need to change. jmap has lots of other requirements, so it's already a big project. by implementing a webmail now, some of the required data structure changes become clear and can be made now, so the later jmap implementation can do things similarly to the webmail code. the webmail frontend and webmail are written together, making their interface/api much smaller and simpler than jmap. one of the internal changes is that we now keep track of per-mailbox total/unread/unseen/deleted message counts and mailbox sizes. keeping this data consistent after any change to the stored messages (through the code base) is tricky, so mox now has a consistency check that verifies the counts are correct, which runs only during tests, each time an internal account reference is closed. we have a few more internal "changes" that are propagated for the webmail frontend (that imap doesn't have a way to propagate on a connection), like changes to the special-use flags on mailboxes, and used keywords in a mailbox. more changes that will be required have revealed themselves while implementing the webmail, and will be implemented next. the webmail user interface is modeled after the mail clients i use or have used: thunderbird, macos mail, mutt; and webmails i normally only use for testing: gmail, proton, yahoo, outlook. a somewhat technical user is assumed, but still the goal is to make this webmail client easy to use for everyone. the user interface looks like most other mail clients: a list of mailboxes, a search bar, a message list view, and message details. there is a top/bottom and a left/right layout for the list/message view, default is automatic based on screen size. the panes can be resized by the user. buttons for actions are just text, not icons. clicking a button briefly shows the shortcut for the action in the bottom right, helping with learning to operate quickly. any text that is underdotted has a title attribute that causes more information to be displayed, e.g. what a button does or a field is about. to highlight potential phishing attempts, any text (anywhere in the webclient) that switches unicode "blocks" (a rough approximation to (language) scripts) within a word is underlined orange. multiple messages can be selected with familiar ui interaction: clicking while holding control and/or shift keys. keyboard navigation works with arrows/page up/down and home/end keys, and also with a few basic vi-like keys for list/message navigation. we prefer showing the text instead of html (with inlined images only) version of a message. html messages are shown in an iframe served from an endpoint with CSP headers to prevent dangerous resources (scripts, external images) from being loaded. the html is also sanitized, with javascript removed. a user can choose to load external resources (e.g. images for tracking purposes). the frontend is just (strict) typescript, no external frameworks. all incoming/outgoing data is typechecked, both the api request parameters and response types, and the data coming in over SSE. the types and checking code are generated with sherpats, which uses the api definitions generated by sherpadoc based on the Go code. so types from the backend are automatically propagated to the frontend. since there is no framework to automatically propagate properties and rerender components, changes coming in over the SSE connection are propagated explicitly with regular function calls. the ui is separated into "views", each with a "root" dom element that is added to the visible document. these views have additional functions for getting changes propagated, often resulting in the view updating its (internal) ui state (dom). we keep the frontend compilation simple, it's just a few typescript files that get compiled (combined and types stripped) into a single js file, no additional runtime code needed or complicated build processes used. the webmail is served is served from a compressed, cachable html file that includes style and the javascript, currently just over 225kb uncompressed, under 60kb compressed (not minified, including comments). we include the generated js files in the repository, to keep Go's easily buildable self-contained binaries. authentication is basic http, as with the account and admin pages. most data comes in over one long-term SSE connection to the backend. api requests signal which mailbox/search/messages are requested over the SSE connection. fetching individual messages, and making changes, are done through api calls. the operations are similar to imap, so some code has been moved from package imapserver to package store. the future jmap implementation will benefit from these changes too. more functionality will probably be moved to the store package in the future. the quickstart enables webmail on the internal listener by default (for new installs). users can enable it on the public listener if they want to. mox localserve enables it too. to enable webmail on existing installs, add settings like the following to the listeners in mox.conf, similar to AccountHTTP(S): WebmailHTTP: Enabled: true WebmailHTTPS: Enabled: true special thanks to liesbeth, gerben, andrii for early user feedback. there is plenty still to do, see the list at the top of webmail/webmail.ts. feedback welcome as always.	2023-08-07 21:57:03 +02:00