add and use cgiurl_abs_samescheme

* emailauth: Fix cookie problem when user is on https and the cgiurl
   uses http, by making the emailed login link use https.
 * passwordauth: Use https for emailed password reset link when user
   is on https.

Not entirely happy with this approach, but I don't currently see a
better one.

I have not verified that the passwordauth change fixes any problem,
other than the user getting a http link when they were using https.
The emailauth problem is verified fixed by this commit.

This commit was sponsored by Michael Magin.

IkiWiki.pm

@@ -1232,6 +1232,19 @@ sub cgiurl_abs (@) {
 	URI->new_abs(cgiurl(@_), $config{cgiurl});
 }
 
+# Same as cgiurl_abs, but when the user connected using https,
+# will be a https url even if the cgiurl is normally a http url.
+#
+# This should be used for anything involving emailing a login link,
+# because a https session cookie will not be sent over http.
+sub cgiurl_abs_samescheme (@) {
+	my $u=cgiurl_abs(@_);
+	if (($ENV{HTTPS} && lc $ENV{HTTPS} ne "off")) {
+		$u=~s/^http:/https:/i;
+	}
+	return $u
+}
+
 sub baseurl (;$) {
 	my $page=shift;
 

IkiWiki/Plugin/emailauth.pm

@@ -76,7 +76,7 @@ sub email_auth ($$$$) {
 	$template->param(
 		wikiname => $config{wikiname},
 		# Intentionally using short field names to keep link short.
-		authurl => IkiWiki::cgiurl_abs(
+		authurl => IkiWiki::cgiurl_abs_samescheme(
 			'e' => $email,
 			'v' => $token,
 		),

IkiWiki/Plugin/passwordauth.pm

@@ -358,7 +358,7 @@ sub formbuilder (@) {
 				my $template=template("passwordmail.tmpl");
 				$template->param(
 					user_name => $user_name,
-					passwordurl => IkiWiki::cgiurl_abs(
+					passwordurl => IkiWiki::cgiurl_abs_samescheme(
 						'do' => "reset",
 						'name' => $user_name,
 						'token' => $token,

debian/changelog

@@ -1,5 +1,9 @@
 ikiwiki (3.20171002) UNRELEASED; urgency=medium
 
+  * emailauth: Fix cookie problem when user is on https and the cgiurl
+    uses http, by making the emailed login link use https.
+  * passwordauth: Use https for emailed password reset link when user
+    is on https.
   * Updated German basewiki and directives translation from
     Sebastian Kuhnert.
 

doc/bugs/login_problem.mdwn

@@ -18,10 +18,21 @@ firefox-esr, or chromium. --[[Joey]]
 > Ok, to reproduce the problem: Log into joeyh.name using https. The email
 > login link is a http link. The session cookie was set https-only.
 > --[[Joey]]
-
+> 
+> The reason the edit form is able to be displayed is that emailauth
+> sets up a session, in getsession(), and that $session is used for the
+> remainder of that cgi call. But, a cookie for that session is not stored
+> in the browser in this case. Ikiwiki *does* send a session cookie, but
+> the browser seems to not let an existing https-only session cookie be
+> replaced by a new session cookie that can be used with http. (If the
+> emailed link, generated on https is opened in a different browser, this
+> problem doesn't happen.) There may have been a browser behavior change
+> here?
+> 
 > So what to do about this? Sites with the problem have `redirect_to_https: 0`
-> and the cgiurl is http not https. So when emailauth generates the url,
-> it's a http url, even if the user got to that point using https.
+> and the cgiurl is http not https. So when emailauth generates the url
+> with `cgiurl_abs`, it's a http url, even if the user got to that point
+> using https.
 > 
 > I suppose that emailauth could look at `$ENV{HTTPS}` same as
 > printheader() does, to detect this case, and rewrite the cgiurl as a
@@ -31,3 +42,12 @@ firefox-esr, or chromium. --[[Joey]]
 > 
 > Of course, the easy workaround, increasingly a good idea anyway, is to
 > enable `redirect_to_https`.. --[[Joey]]
+
+> One of the users also reported a problem with password reset, and
+> indeed, passwordauth is another caller of `cgiurl_abs`. (The only other
+> caller, notifyemail, is probably fine.) The emailed password reset link
+> also should be https if the user was using https. So, let's add a
+> `cgiurl_abs_samescheme` that both can use. --[[Joey]]
+
+[[fixed|done]].. At least I hope that was the thing actually preventing most
+of the people from logging in. --[[Joey]]