X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/54cf5a62cab254e923c8d73ae8bd043a1f33c3b1..f768b6bf16e043b41d4503f3ab0758d975994b12:/IkiWiki/CGI.pm?ds=sidebyside

diff --git a/IkiWiki/CGI.pm b/IkiWiki/CGI.pm
index def0549c5..f2a32a958 100644
--- a/IkiWiki/CGI.pm
+++ b/IkiWiki/CGI.pm
@@ -1,5 +1,7 @@
 #!/usr/bin/perl
 
+package IkiWiki;
+
 use warnings;
 use strict;
 use IkiWiki;
@@ -7,23 +9,50 @@ use IkiWiki::UserInfo;
 use open qw{:utf8 :std};
 use Encode;
 
-package IkiWiki;
-
-sub printheader ($) { #{{{
+sub printheader ($) {
 	my $session=shift;
 	
 	if ($config{sslcookie}) {
 		print $session->header(-charset => 'utf-8',
-			-cookie => $session->cookie(-secure => 1));
-	} else {
-		print $session->header(-charset => 'utf-8');
+			-cookie => $session->cookie(-httponly => 1, -secure => 1));
+	}
+	else {
+		print $session->header(-charset => 'utf-8',
+			-cookie => $session->cookie(-httponly => 1));
 	}
+}
 
-} #}}}
+sub prepform {
+	my $form=shift;
+	my $buttons=shift;
+	my $session=shift;
+	my $cgi=shift;
+
+	if (exists $hooks{formbuilder}) {
+		run_hooks(formbuilder => sub {
+			shift->(form => $form, cgi => $cgi, session => $session,
+				buttons => $buttons);
+		});
+	}
+
+	return $form;
+}
 
-sub redirect ($$) { #{{{
+sub showform ($$$$;@) {
+	my $form=prepform(@_);
+	shift;
+	my $buttons=shift;
+	my $session=shift;
+	my $cgi=shift;
+
+	printheader($session);
+	print misctemplate($form->title, $form->render(submit => $buttons), @_);
+}
+
+sub redirect ($$) {
 	my $q=shift;
-	my $url=shift;
+	eval q{use URI};
+	my $url=URI->new(shift);
 	if (! $config{w3mmode}) {
 		print $q->redirect($url);
 	}
@@ -31,359 +60,175 @@ sub redirect ($$) { #{{{
 		print "Content-type: text/plain\n";
 		print "W3m-control: GOTO $url\n\n";
 	}
-} #}}}
+}
 
-sub page_locked ($$;$) { #{{{
-	my $page=shift;
-	my $session=shift;
-	my $nonfatal=shift;
-	
-	my $user=$session->param("name");
-	return if defined $user && is_admin($user);
-
-	foreach my $admin (@{$config{adminuser}}) {
-		my $locked_pages=userinfo_get($admin, "locked_pages");
-		if (pagespec_match($page, userinfo_get($admin, "locked_pages"))) {
-			return 1 if $nonfatal;
-			error(htmllink("", "", $page, 1)." is locked by ".
-			      htmllink("", "", $admin, 1)." and cannot be edited.");
+sub decode_cgi_utf8 ($) {
+	# decode_form_utf8 method is needed for 5.01
+	if ($] < 5.01) {
+		my $cgi = shift;
+		foreach my $f ($cgi->param) {
+			$cgi->param($f, map { decode_utf8 $_ } $cgi->param($f));
 		}
 	}
+}
 
-	return 0;
-} #}}}
-
-sub decode_form_utf8 ($) { #{{{
-	my $form = shift;
-	foreach my $f ($form->field) {
-		next if Encode::is_utf8(scalar $form->field($f));
-		$form->field(name  => $f,
-			     value => decode_utf8($form->field($f)),
-			     force => 1,
-			    );
+sub decode_form_utf8 ($) {
+	if ($] >= 5.01) {
+		my $form = shift;
+		foreach my $f ($form->field) {
+			my @value=map { decode_utf8($_) } $form->field($f);
+			$form->field(name  => $f,
+			             value => \@value,
+		                     force => 1,
+			);
+		}
 	}
-} #}}}
+}
 
-sub cgi_recentchanges ($) { #{{{
+# Check if the user is signed in. If not, redirect to the signin form and
+# save their place to return to later.
+sub needsignin ($$) {
 	my $q=shift;
-	
-	unlockwiki();
-
-	# Optimisation: building recentchanges means calculating lots of
-	# links. Memoizing htmllink speeds it up a lot (can't be memoized
-	# during page builds as the return values may change, but they
-	# won't here.)
-	eval q{use Memoize};
-	error($@) if $@;
-	memoize("htmllink");
-
-	eval q{use Time::Duration};
-	error($@) if $@;
-	eval q{use CGI 'escapeHTML'};
-	error($@) if $@;
+	my $session=shift;
 
-	my $changelog=[rcs_recentchanges(100)];
-	foreach my $change (@$changelog) {
-		$change->{when} = concise(ago($change->{when}));
-		$change->{user} = htmllink("", "", escapeHTML($change->{user}), 1);
-
-		my $is_excess = exists $change->{pages}[10]; # limit pages to first 10
-		delete @{$change->{pages}}[10 .. @{$change->{pages}}] if $is_excess;
-		$change->{pages} = [
-			map {
-				$_->{link} = htmllink("", "", $_->{page}, 1);
-				$_;
-			} @{$change->{pages}}
-		];
-		push @{$change->{pages}}, { link => '...' } if $is_excess;
+	if (! defined $session->param("name") ||
+	    ! userinfo_get($session->param("name"), "regdate")) {
+		$session->param(postsignin => $ENV{QUERY_STRING});
+		cgi_signin($q, $session);
+		cgi_savesession($session);
+		exit;
 	}
+}
 
-	my $template=template("recentchanges.tmpl"); 
-	$template->param(
-		title => "RecentChanges",
-		indexlink => indexlink(),
-		wikiname => $config{wikiname},
-		changelog => $changelog,
-		baseurl => baseurl(),
-	);
-	run_hooks(pagetemplate => sub {
-		shift->(page => "", destpage => "", template => $template);
-	});
-	print $q->header(-charset => 'utf-8'), $template->output;
-} #}}}
-
-sub cgi_signin ($$) { #{{{
+sub cgi_signin ($$;$) {
 	my $q=shift;
 	my $session=shift;
+	my $returnhtml=shift;
 
+	decode_cgi_utf8($q);
 	eval q{use CGI::FormBuilder};
 	error($@) if $@;
 	my $form = CGI::FormBuilder->new(
 		title => "signin",
-		fields => [qw(do title page subpage from name password openid_url)],
-		header => 1,
+		name => "signin",
 		charset => "utf-8",
 		method => 'POST',
-		validate => {
-			confirm_password => {
-				perl => q{eq $form->field("password")},
-			},
-			email => 'EMAIL',
-		},
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
 		action => $config{cgiurl},
 		header => 0,
-		template => (-e "$config{templatedir}/signin.tmpl" ?
-			     {template_params("signin.tmpl")} : ""),
-		stylesheet => baseurl()."style.css",
+		template => {type => 'div'},
+		stylesheet => 1,
 	);
-		
-	decode_form_utf8($form);
+	my $buttons=["Login"];
 	
-	$form->field(name => "name", required => 0);
-	$form->field(name => "do", type => "hidden");
-	$form->field(name => "page", type => "hidden");
-	$form->field(name => "title", type => "hidden");
-	$form->field(name => "from", type => "hidden");
-	$form->field(name => "subpage", type => "hidden");
-	$form->field(name => "password", type => "password", required => 0);
-	if ($config{openid}) {
-		$form->field(name => "openid_url", label => "OpenID", comment => "to log in via OpenID");
-	}
-	else {
-		$form->field(name => "openid_url", type => "hidden");
-	}
-	if ($form->submitted eq "Register" || $form->submitted eq "Create Account") {
-		$form->title("register");
-		$form->text("");
-		$form->fields(qw(do title page subpage from name password confirm_password email));
-		$form->field(name => "confirm_password", type => "password");
-		$form->field(name => "email", type => "text");
-		$form->field(name => "openid_url", type => "hidden");
-	}
-	if ($q->param("do") ne "signin" && !$form->submitted) {
-		$form->text("You need to log in first.");
-	}
+	$form->field(name => "do", type => "hidden", value => "signin",
+		force => 1);
 	
+	decode_form_utf8($form);
+	run_hooks(formbuilder_setup => sub {
+		shift->(form => $form, cgi => $q, session => $session,
+		        buttons => $buttons);
+	});
+	decode_form_utf8($form);
+
 	if ($form->submitted) {
-		my $submittype=$form->submitted;
-		# OpenID login uses the Login button, but validates
-		# differently.
-		if ($submittype eq "Login" && $config{openid} && 
-		    length $form->field("openid_url")) {
-			$submittype="OpenID";
-			
-			$form->field(
-				name => "openid_url",
-				validate => sub {
-					# FIXME: ugh
-					IkiWiki::Plugin::openid::validate($q, $session, $form, shift);
-				},
-			);
-		}
+		$form->validate;
+	}
 
-		# Set required fields based on how form was submitted.
-		my %required=(
-			"Login" => [qw(name password)],
-			"Register" => [],
-			"Create Account" => [qw(name password confirm_password email)],
-			"Mail Password" => [qw(name)],
-			"OpenID" => [qw(openid_url)],
-		);
-		foreach my $opt (@{$required{$submittype}}) {
-			$form->field(name => $opt, required => 1);
-		}
+	if ($returnhtml) {
+		$form=prepform($form, $buttons, $session, $q);
+		return $form->render(submit => $buttons);
+	}
+
+	showform($form, $buttons, $session, $q);
+}
+
+sub cgi_postsignin ($$) {
+	my $q=shift;
+	my $session=shift;
 	
-		# Validate password differently depending on how
-		# form was submitted.
-		if ($submittype eq 'Login') {
-			$form->field(
-				name => "password",
-				validate => sub {
-					length $form->field("name") &&
-					shift eq userinfo_get($form->field("name"), 'password');
-				},
-			);
-			$form->field(name => "name", validate => '/^\w+$/');
-		}
-		elsif ($submittype ne 'OpenID') {
-			$form->field(name => "password", validate => 'VALUE');
-		}
-		# And make sure the entered name exists when logging
-		# in or sending email, and does not when registering.
-		if ($submittype eq 'Create Account' ||
-		    $submittype eq 'Register') {
-			$form->field(
-				name => "name",
-				validate => sub {
-					my $name=shift;
-					length $name &&
-					$name=~/$config{wiki_file_regexp}/ &&
-					! userinfo_get($name, "regdate");
-				},
-			);
-		}
-		elsif ($submittype ne 'OpenID') {
-			$form->field(
-				name => "name",
-				validate => sub {
-					my $name=shift;
-					length $name &&
-					userinfo_get($name, "regdate");
-				},
-			);
-		}
+	# Continue with whatever was being done before the signin process.
+	if (defined $session->param("postsignin")) {
+		my $postsignin=CGI->new($session->param("postsignin"));
+		$session->clear("postsignin");
+		cgi($postsignin, $session);
+		cgi_savesession($session);
+		exit;
 	}
 	else {
-		# First time settings.
-		$form->field(name => "name", comment => "use FirstnameLastName");
-		if ($session->param("name")) {
-			$form->field(name => "name", value => $session->param("name"));
+		if ($config{sslcookie} && ! $q->https()) {
+			error(gettext("probable misconfiguration: sslcookie is set, but you are attempting to login via http, not https"));
 		}
-	}
-
-	if ($form->submitted && $form->validate) {
-		if ($form->submitted eq 'Login') {
-			$session->param("name", $form->field("name"));
-			if (defined $form->field("do") && 
-			    $form->field("do") ne 'signin') {
-				redirect($q, cgiurl(
-					do => $form->field("do"),
-					page => $form->field("page"),
-					title => $form->field("title"),
-					from => $form->field("from"),
-					subpage => $form->field("subpage"),
-				));
-			}
-			else {
-				redirect($q, $config{url});
-			}
-		}
-		elsif ($form->submitted eq 'Create Account') {
-			my $user_name=$form->field('name');
-			if (userinfo_setall($user_name, {
-				           'email' => $form->field('email'),
-				           'password' => $form->field('password'),
-				           'regdate' => time
-				         })) {
-				$form->field(name => "confirm_password", type => "hidden");
-				$form->field(name => "email", type => "hidden");
-				$form->text("Account creation successful. Now you can Login.");
-				printheader($session);
-				print misctemplate($form->title, $form->render(submit => ["Login"]));
-			}
-			else {
-				error("Error creating account.");
-			}
-		}
-		elsif ($form->submitted eq 'Mail Password') {
-			my $user_name=$form->field("name");
-			my $template=template("passwordmail.tmpl");
-			$template->param(
-				user_name => $user_name,
-				user_password => userinfo_get($user_name, "password"),
-				wikiurl => $config{url},
-				wikiname => $config{wikiname},
-				REMOTE_ADDR => $ENV{REMOTE_ADDR},
-			);
-			
-			eval q{use Mail::Sendmail};
-			error($@) if $@;
-			sendmail(
-				To => userinfo_get($user_name, "email"),
-				From => "$config{wikiname} admin <$config{adminemail}>",
-				Subject => "$config{wikiname} information",
-				Message => $template->output,
-			) or error("Failed to send mail");
-			
-			$form->text("Your password has been emailed to you.");
-			$form->field(name => "name", required => 0);
-			printheader($session);
-			print misctemplate($form->title, $form->render(submit => ["Login", "Mail Password"]));
-		}
-		elsif ($form->submitted eq "Register") {
-			printheader($session);
-			print misctemplate($form->title, $form->render(submit => ["Create Account"]));
+		else {
+			error(gettext("login failed, perhaps you need to turn on cookies?"));
 		}
 	}
-	elsif ($form->submitted eq "Create Account") {
-		printheader($session);
-		print misctemplate($form->title, $form->render(submit => ["Create Account"]));
-	}
-	else {
-		printheader($session);
-		print misctemplate($form->title, $form->render(submit => ["Login", "Register", "Mail Password"]));
-	}
-} #}}}
+}
 
-sub cgi_prefs ($$) { #{{{
+sub cgi_prefs ($$) {
 	my $q=shift;
 	my $session=shift;
 
+	needsignin($q, $session);
+	decode_cgi_utf8($q);
+	
+	# The session id is stored on the form and checked to
+	# guard against CSRF.
+	my $sid=$q->param('sid');
+	if (! defined $sid) {
+		$q->delete_all;
+	}
+	elsif ($sid ne $session->id) {
+		error(gettext("Your login session has expired."));
+	}
+
 	eval q{use CGI::FormBuilder};
 	error($@) if $@;
 	my $form = CGI::FormBuilder->new(
 		title => "preferences",
-		fields => [qw(do name password confirm_password email 
-		              subscriptions locked_pages)],
+		name => "preferences",
 		header => 0,
 		charset => "utf-8",
 		method => 'POST',
 		validate => {
-			confirm_password => {
-				perl => q{eq $form->field("password")},
-			},
 			email => 'EMAIL',
 		},
 		required => 'NONE',
 		javascript => 0,
 		params => $q,
 		action => $config{cgiurl},
-		template => (-e "$config{templatedir}/prefs.tmpl" ?
-			     {template_params("prefs.tmpl")} : ""),
-		stylesheet => baseurl()."style.css",
+		template => {type => 'div'},
+		stylesheet => 1,
+		fieldsets => [
+			[login => gettext("Login")],
+			[preferences => gettext("Preferences")],
+			[admin => gettext("Admin")]
+		],
 	);
-	my @buttons=("Save Preferences", "Logout", "Cancel");
+	my $buttons=["Save Preferences", "Logout", "Cancel"];
 	
-	my $user_name=$session->param("name");
-	$form->field(name => "do", type => "hidden");
-	$form->field(name => "name", disabled => 1,
-		value => $user_name, force => 1);
-	$form->field(name => "password", type => "password");
-	$form->field(name => "confirm_password", type => "password");
-	$form->field(name => "subscriptions", size => 50,
-		comment => "(".htmllink("", "", "PageSpec", 1).")");
-	$form->field(name => "locked_pages", size => 50,
-		comment => "(".htmllink("", "", "PageSpec", 1).")");
-	$form->field(name => "banned_users", size => 50);
+	decode_form_utf8($form);
+	run_hooks(formbuilder_setup => sub {
+		shift->(form => $form, cgi => $q, session => $session,
+		        buttons => $buttons);
+	});
+	decode_form_utf8($form);
 	
-	if (! is_admin($user_name)) {
-		$form->field(name => "locked_pages", type => "hidden");
-		$form->field(name => "banned_users", type => "hidden");
-	}
-
-	if ($config{httpauth}) {
-		$form->field(name => "password", type => "hidden");
-		$form->field(name => "confirm_password", type => "hidden");
-	}
+	$form->field(name => "do", type => "hidden", value => "prefs",
+		force => 1);
+	$form->field(name => "sid", type => "hidden", value => $session->id,
+		force => 1);
+	$form->field(name => "email", size => 50, fieldset => "preferences");
 	
+	my $user_name=$session->param("name");
+
 	if (! $form->submitted) {
 		$form->field(name => "email", force => 1,
 			value => userinfo_get($user_name, "email"));
-		$form->field(name => "subscriptions", force => 1,
-			value => userinfo_get($user_name, "subscriptions"));
-		$form->field(name => "locked_pages", force => 1,
-			value => userinfo_get($user_name, "locked_pages"));
-		if (is_admin($user_name)) {
-			$form->field(name => "banned_users", force => 1,
-				value => join(" ", get_banned_users()));
-		}
 	}
 	
-	decode_form_utf8($form);
-	
 	if ($form->submitted eq 'Logout') {
 		$session->delete();
 		redirect($q, $config{url});
@@ -393,290 +238,130 @@ sub cgi_prefs ($$) { #{{{
 		redirect($q, $config{url});
 		return;
 	}
-	elsif ($form->submitted eq "Save Preferences" && $form->validate) {
-		foreach my $field (qw(password email subscriptions locked_pages)) {
-			if (length $form->field($field)) {
-				userinfo_set($user_name, $field, $form->field($field)) || error("failed to set $field");
-			}
-		}
-		if (is_admin($user_name)) {
-			set_banned_users(grep { ! is_admin($_) }
-					split(' ', $form->field("banned_users")));
+	elsif ($form->submitted eq 'Save Preferences' && $form->validate) {
+		if (defined $form->field('email')) {
+			userinfo_set($user_name, 'email', $form->field('email')) ||
+				error("failed to set email");
 		}
-		$form->text("Preferences saved.");
+
+		$form->text(gettext("Preferences saved."));
 	}
 	
-	printheader($session);
-	print misctemplate($form->title, $form->render(submit => \@buttons));
-} #}}}
+	showform($form, $buttons, $session, $q,
+		prefsurl => "", # avoid showing the preferences link
+	);
+}
 
-sub cgi_editpage ($$) { #{{{
+sub cgi_custom_failure ($$$) {
 	my $q=shift;
-	my $session=shift;
+	my $httpstatus=shift;
+	my $message=shift;
 
-	my @fields=qw(do rcsinfo subpage from page type editcontent comments);
-	my @buttons=("Save Page", "Preview", "Cancel");
-	
-	eval q{use CGI::FormBuilder; use CGI::FormBuilder::Template::HTML};
-	error($@) if $@;
-	my $renderer=CGI::FormBuilder::Template::HTML->new(
-		fields => \@fields,
-		template_params("editpage.tmpl"),
+	print $q->header(
+		-status => $httpstatus,
+		-charset => 'utf-8',
 	);
-	run_hooks(pagetemplate => sub {
-		shift->(page => "", destpage => "", template => $renderer->engine);
-	});
-	my $form = CGI::FormBuilder->new(
-		fields => \@fields,
-		header => 1,
-		charset => "utf-8",
-		method => 'POST',
-		validate => {
-			editcontent => '/.+/',
-		},
-		required => [qw{editcontent}],
-		javascript => 0,
-		params => $q,
-		action => $config{cgiurl},
-		table => 0,
-		template => $renderer,
-	);
-	
-	decode_form_utf8($form);
-	
-	# This untaint is safe because titlepage removes any problematic
-	# characters.
-	my ($page)=$form->field('page');
-	$page=titlepage(possibly_foolish_untaint($page));
-	if (! defined $page || ! length $page ||
-	    $page=~/$config{wiki_file_prune_regexp}/ || $page=~/^\//) {
-		error("bad page name");
-	}
-	
-	my $from;
-	if (defined $form->field('from')) {
-		($from)=$form->field('from')=~/$config{wiki_file_regexp}/;
-	}
-	
-	my $file;
-	my $type;
-	if (exists $pagesources{$page}) {
-		$file=$pagesources{$page};
-		$type=pagetype($file);
+	print $message;
+
+	# Internet Explod^Hrer won't show custom 404 responses
+	# unless they're >= 512 bytes
+	print ' ' x 512;
+
+	exit;
+}
+
+sub check_banned ($$) {
+	my $q=shift;
+	my $session=shift;
+
+	my $banned=0;
+	my $name=$session->param("name");
+	if (defined $name && 
+	    grep { $name eq $_ } @{$config{banned_users}}) {
+		$banned=1;
 	}
-	else {
-		$type=$form->param('type');
-		if (defined $type && length $type && $hooks{htmlize}{$type}) {
-			$type=possibly_foolish_untaint($type);
-		}
-		elsif (defined $from) {
-			# favor the type of linking page
-			$type=pagetype($pagesources{$from});
+
+	foreach my $b (@{$config{banned_users}}) {
+		if (pagespec_match("", $b,
+			ip => $session->remote_addr(),
+			name => defined $name ? $name : "",
+		)) {
+			$banned=1;
+			last;
 		}
-		$type=$config{default_pageext} unless defined $type;
-		$file=$page.".".$type;
 	}
 
-	my $newfile=0;
-	if (! -e "$config{srcdir}/$file") {
-		$newfile=1;
+	if ($banned) {
+		$session->delete();
+		cgi_savesession($session);
+		cgi_custom_failure(
+			$q, "403 Forbidden",
+			gettext("You are banned."));
 	}
+}
 
-	$form->field(name => "do", type => 'hidden');
-	$form->field(name => "from", type => 'hidden');
-	$form->field(name => "rcsinfo", type => 'hidden');
-	$form->field(name => "subpage", type => 'hidden');
-	$form->field(name => "page", value => $page, force => 1);
-	$form->field(name => "type", value => $type, force => 1);
-	$form->field(name => "comments", type => "text", size => 80);
-	$form->field(name => "editcontent", type => "textarea", rows => 20,
-		cols => 80);
-	$form->tmpl_param("can_commit", $config{rcs});
-	$form->tmpl_param("indexlink", indexlink());
-	$form->tmpl_param("helponformattinglink",
-		htmllink("", "", "HelpOnFormatting", 1));
-	$form->tmpl_param("baseurl", baseurl());
-	if (! $form->submitted) {
-		$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-			force => 1);
-	}
+sub cgi_getsession ($) {
+	my $q=shift;
+
+	eval q{use CGI::Session; use HTML::Entities};
+	error($@) if $@;
+	CGI::Session->name("ikiwiki_session_".encode_entities($config{wikiname}));
 	
-	if ($form->submitted eq "Cancel") {
-		if ($newfile && defined $from) {
-			redirect($q, "$config{url}/".htmlpage($from));
-		}
-		elsif ($newfile) {
-			redirect($q, $config{url});
-		}
-		else {
-			redirect($q, "$config{url}/".htmlpage($page));
-		}
-		return;
-	}
-	elsif ($form->submitted eq "Preview") {
-		my $content=$form->field('editcontent');
-		my $comments=$form->field('comments');
-		$form->field(name => "editcontent",
-				value => $content, force => 1);
-		$form->field(name => "comments",
-				value => $comments, force => 1);
-		$config{rss}=$config{atom}=0; # avoid preview writing a feed!
-		$form->tmpl_param("page_preview",
-			htmlize($page, $type,
-			linkify($page, "",
-			preprocess($page, $page,
-			filter($page, $content)))));
-	}
-	else {
-		$form->tmpl_param("page_preview", "");
+	my $oldmask=umask(077);
+	my $session = eval {
+		CGI::Session->new("driver:DB_File", $q,
+			{ FileName => "$config{wikistatedir}/sessions.db" })
+	};
+	if (! $session || $@) {
+		error($@." ".CGI::Session->errstr());
 	}
-	$form->tmpl_param("page_conflict", "");
 	
-	if (! $form->submitted || $form->submitted eq "Preview" || 
-	    ! $form->validate) {
-		if ($form->field("do") eq "create") {
-			my @page_locs;
-			my $best_loc;
-			if (! defined $from || ! length $from ||
-			    $from ne $form->field('from') ||
-			    $from=~/$config{wiki_file_prune_regexp}/ ||
-			    $from=~/^\// ||
-			    $form->submitted eq "Preview") {
-				@page_locs=$best_loc=$page;
-			}
-			else {
-				my $dir=$from."/";
-				$dir=~s![^/]+/+$!!;
-				
-				if ((defined $form->field('subpage') && length $form->field('subpage')) ||
-				    $page eq 'discussion') {
-					$best_loc="$from/$page";
-				}
-				else {
-					$best_loc=$dir.$page;
-				}
-				
-				push @page_locs, $dir.$page;
-				push @page_locs, "$from/$page";
-				while (length $dir) {
-					$dir=~s![^/]+/+$!!;
-					push @page_locs, $dir.$page;
-				}
-			}
+	umask($oldmask);
 
-			@page_locs = grep {
-				! exists $pagecase{lc $_} &&
-				! page_locked($_, $session, 1)
-			} @page_locs;
-			
-			if (! @page_locs) {
-				# hmm, someone else made the page in the
-				# meantime?
-				redirect($q, "$config{url}/".htmlpage($page));
-				return;
-			}
-			
-			my @page_types;
-			if (exists $hooks{htmlize}) {
-				@page_types=keys %{$hooks{htmlize}};
-			}
-			
-			$form->tmpl_param("page_select", 1);
-			$form->field(name => "page", type => 'select',
-				options => \@page_locs, value => $best_loc);
-			$form->field(name => "type", type => 'select',
-				options => \@page_types);
-			$form->title("creating ".pagetitle($page));
-		}
-		elsif ($form->field("do") eq "edit") {
-			page_locked($page, $session);
-			if (! defined $form->field('editcontent') || 
-			    ! length $form->field('editcontent')) {
-				my $content="";
-				if (exists $pagesources{$page}) {
-					$content=readfile(srcfile($pagesources{$page}));
-					$content=~s/\n/\r\n/g;
-				}
-				$form->field(name => "editcontent", value => $content,
-					force => 1);
-			}
-			$form->tmpl_param("page_select", 0);
-			$form->field(name => "page", type => 'hidden');
-			$form->field(name => "type", type => 'hidden');
-			$form->title("editing ".pagetitle($page));
-		}
-		
-		print $form->render(submit => \@buttons);
-	}
-	else {
-		# save page
-		page_locked($page, $session);
-		
-		my $content=$form->field('editcontent');
-
-		$content=~s/\r\n/\n/g;
-		$content=~s/\r/\n/g;
-		writefile($file, $config{srcdir}, $content);
-		
-		my $message="web commit ";
-		if (defined $session->param("name") && 
-		    length $session->param("name")) {
-			$message.="by ".$session->param("name");
-		}
-		else {
-			$message.="from $ENV{REMOTE_ADDR}";
-		}
-		if (defined $form->field('comments') &&
-		    length $form->field('comments')) {
-			$message.=": ".$form->field('comments');
-		}
-		
-		if ($config{rcs}) {
-			if ($newfile) {
-				rcs_add($file);
-			}
-			# prevent deadlock with post-commit hook
-			unlockwiki();
-			# presumably the commit will trigger an update
-			# of the wiki
-			my $conflict=rcs_commit($file, $message,
-				$form->field("rcsinfo"));
-		
-			if (defined $conflict) {
-				$form->field(name => "rcsinfo", value => rcs_prepedit($file),
-					force => 1);
-				$form->tmpl_param("page_conflict", 1);
-				$form->field("editcontent", value => $conflict, force => 1);
-				$form->field(name => "comments", value => $form->field('comments'), force => 1);
-				$form->field("do", "edit)");
-				$form->tmpl_param("page_select", 0);
-				$form->field(name => "page", type => 'hidden');
-				$form->field(name => "type", type => 'hidden');
-				$form->title("editing $page");
-				print $form->render(submit => \@buttons);
-				return;
-			}
-		}
-		else {
-			require IkiWiki::Render;
-			refresh();
-			saveindex();
+	return $session;
+}
+
+# To guard against CSRF, the user's session id (sid)
+# can be stored on a form. This function will check
+# (for logged in users) that the sid on the form matches
+# the session id in the cookie.
+sub checksessionexpiry ($$) {
+	my $q=shift;
+	my $session = shift;
+
+	if (defined $session->param("name")) {
+		my $sid=$q->param('sid');
+		if (! defined $sid || $sid ne $session->id) {
+			error(gettext("Your login session has expired."));
 		}
-		
-		# The trailing question mark tries to avoid broken
-		# caches and get the most recent version of the page.
-		redirect($q, "$config{url}/".htmlpage($page)."?updated");
 	}
-} #}}}
+}
+
+sub cgi_savesession ($) {
+	my $session=shift;
+
+	# Force session flush with safe umask.
+	my $oldmask=umask(077);
+	$session->flush;
+	umask($oldmask);
+}
+
+sub cgi (;$$) {
+	my $q=shift;
+	my $session=shift;
 
-sub cgi () { #{{{
-	eval q{use CGI; use CGI::Session};
+	eval q{use CGI};
 	error($@) if $@;
+	$CGI::DISABLE_UPLOADS=$config{cgi_disable_uploads};
+
+	if (! $q) {
+		binmode(STDIN);
+		$q=CGI->new;
+		binmode(STDIN, ":utf8");
 	
-	my $q=CGI->new;
-	
-	run_hooks(cgi => sub { shift->($q) });
-	
+		run_hooks(cgi => sub { shift->($q) });
+	}
+
 	my $do=$q->param('do');
 	if (! defined $do || ! length $do) {
 		my $error = $q->cgi_error;
@@ -687,22 +372,14 @@ sub cgi () { #{{{
 			error("\"do\" parameter missing");
 		}
 	}
+
+	# Need to lock the wiki before getting a session.
+	lockwiki();
+	loadindex();
 	
-	# Things that do not need a session.
-	if ($do eq 'recentchanges') {
-		cgi_recentchanges($q);
-		return;
+	if (! $session) {
+		$session=cgi_getsession($q);
 	}
-	elsif ($do eq 'hyperestraier') {
-		cgi_hyperestraier();
-	}
-	
-	CGI::Session->name("ikiwiki_session_".encode_utf8($config{wikiname}));
-	
-	my $oldmask=umask(077);
-	my $session = CGI::Session->new("driver:DB_File", $q,
-		{ FileName => "$config{wikistatedir}/sessions.db" });
-	umask($oldmask);
 	
 	# Auth hooks can sign a user in.
 	if ($do ne 'signin' && ! defined $session->param("name")) {
@@ -717,57 +394,38 @@ sub cgi () { #{{{
 					email => "",
 					password => "",
 					regdate => time,
-				});
+				}) || error("failed adding user");
 			}
 		}
 	}
-
-	# Everything below this point needs the user to be signed in.
-	if (((! $config{anonok} || $do eq 'prefs') &&
-	     (! $config{httpauth}) &&
-	     (! defined $session->param("name") ||
-	     ! userinfo_get($session->param("name"), "regdate")))
-            || $do eq 'signin') {
-		cgi_signin($q, $session);
 	
-		# Force session flush with safe umask.
-		my $oldmask=umask(077);
-		$session->flush;
-		umask($oldmask);
-		
-		return;
-	}
-
-	if (defined $session->param("name") && userinfo_get($session->param("name"), "banned")) {
-		print $q->header(-status => "403 Forbidden");
-		$session->delete();
-		print "You are banned.";
-		exit;
-	}
+	check_banned($q, $session);
 	
-	if ($do eq 'create' || $do eq 'edit') {
-		cgi_editpage($q, $session);
+	run_hooks(sessioncgi => sub { shift->($q, $session) });
+
+	if ($do eq 'signin') {
+		cgi_signin($q, $session);
+		cgi_savesession($session);
 	}
 	elsif ($do eq 'prefs') {
 		cgi_prefs($q, $session);
 	}
-	elsif ($do eq 'blog') {
-		my $page=titlepage(decode_utf8($q->param('title')));
-		# if the page already exists, munge it to be unique
-		my $from=$q->param('from');
-		my $add="";
-		while (exists $pagecase{lc "$from/$page$add"}) {
-			$add=1 unless length $add;
-			$add++;
-		}
-		$q->param('page', $page.$add);
-		# now run same as create
-		$q->param('do', 'create');
-		cgi_editpage($q, $session);
+	elsif (defined $session->param("postsignin") || $do eq 'postsignin') {
+		cgi_postsignin($q, $session);
 	}
 	else {
 		error("unknown do parameter");
 	}
-} #}}}
+}
+
+# Does not need to be called directly; all errors will go through here.
+sub cgierror ($) {
+	my $message=shift;
+
+	print "Content-type: text/html\n\n";
+	print misctemplate(gettext("Error"),
+		"<p class=\"error\">".gettext("Error").": $message</p>");
+	die $@;
+}
 
 1