+# Generates a token that can be used to log the user in.
+# This needs to be hard to guess. Generating a cgi session id will
+# make it as hard to guess as any cgi session.
+sub gentoken ($$;$) {
+ my $user=shift;
+ my $tokenfield=shift;
+ my $reversable=shift;
+
+ eval q{use CGI::Session};
+ error($@) if $@;
+ my $token = CGI::Session->new->id;
+ if (! $reversable) {
+ setpassword($user, $token, $tokenfield);
+ }
+ else {
+ IkiWiki::userinfo_set($user, $tokenfield, $token);
+ }
+ return $token;
+}
+
+# An anonymous user has no normal password, only a passwordless login
+# token. Given an email address, this sets up such a user for that email,
+# unless one already exists, and returns the username.
+sub anonuser ($) {
+ my $email=shift;
+
+ # Want a username for this email that won't overlap with any other.
+ my $user=$email;
+ $user=~s/@/_/g;
+
+ my $userinfo=IkiWiki::userinfo_retrieve();
+ if (! exists $userinfo->{$user} || ! ref $userinfo->{$user}) {
+ if (IkiWiki::userinfo_setall($user, {
+ 'email' => $email,
+ 'regdate' => time})) {
+ gentoken($user, "passwordless", 1);
+ return $user;
+ }
+ else {
+ error(gettext("Error creating account."));
+ }
+ }
+ elsif (defined anonusertoken($userinfo->{$user})) {
+ return $user;
+ }
+ else {
+ return undef;
+ }
+}
+
+sub anonusertoken ($) {
+ my $userhash=shift;
+ if (exists $userhash->{passwordless} &&
+ length $userhash->{passwordless}) {
+ return $userhash->{passwordless};
+ }
+ else {
+ return undef;
+ }
+}
+