X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/7691899da03a972ab89d6294478df281a3aa6e0f..a6dabc247f47788344a4e99848dc0859c2e622c3:/doc/plugins/po.mdwn?ds=sidebyside diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn index 6a2409847..f19557a66 100644 --- a/doc/plugins/po.mdwn +++ b/doc/plugins/po.mdwn @@ -5,8 +5,10 @@ This plugin adds support for multi-lingual wikis, translated with gettext, using [po4a](http://po4a.alioth.debian.org/). It depends on the Perl `Locale::Po4a::Po` library (`apt-get install po4a`). +As detailed bellow in the security section, `po4a` is subject to +denial-of-service attacks before version 0.35. -[[!toc]] +[[!toc levels=2]] Introduction ============ @@ -31,6 +33,12 @@ Example: `bla/page.fr.po` is the PO "message catalog" used to translate `bla/page.mdwn` into French; if `usedirs` is enabled, it is rendered as `bla/page/index.fr.html`, else as `bla/page.fr.html` +(In)Compatibility +================= + +This plugin does not support the `indexpages` mode. If you don't know +what it is, you probably don't care. + Configuration ============= @@ -64,39 +72,40 @@ worry about excluding them explicitly from this [[ikiwiki/PageSpec]]. Internal links -------------- +### Links targets + The `po_link_to` option in `ikiwiki.setup` is used to decide how internal links should be generated, depending on web server features and site-specific preferences. -### Default linking behavior +#### Default linking behavior If `po_link_to` is unset, or set to `default`, ikiwiki's default linking behavior is preserved: `\[[destpage]]` links to the master language's page. -### Link to current language +#### Link to current language If `po_link_to` is set to `current`, `\[[destpage]]` links to the `destpage`'s version written in the current page's language, if available, *i.e.*: -- `foo/destpage/index.LL.html` if `usedirs` is enabled -- `foo/destpage.LL.html` if `usedirs` is disabled +* `foo/destpage/index.LL.html` if `usedirs` is enabled +* `foo/destpage.LL.html` if `usedirs` is disabled -### Link to negotiated language +#### Link to negotiated language If `po_link_to` is set to `negotiated`, `\[[page]]` links to the negotiated preferred language, *i.e.* `foo/page/`. (In)compatibility notes: -- if `usedirs` is disabled, it does not make sense to set `po_link_to` +* if `usedirs` is disabled, it does not make sense to set `po_link_to` to `negotiated`; this option combination is neither implemented nor allowed. -- if the web server does not support Content Negotiation, setting +* if the web server does not support Content Negotiation, setting `po_link_to` to `negotiated` will produce a unusable website. - Server support ============== @@ -129,6 +138,10 @@ Usage Templates --------- +When `po_link_to` is not set to `negotiated`, one should replace some +occurrences of `BASEURL` with `HOMEPAGEURL` to get correct links to +the wiki homepage. + The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to display things only on translatable or translation pages. @@ -137,43 +150,21 @@ display things only on translatable or translation pages. The `OTHERLANGUAGES` loop provides ways to display other languages' versions of the same page, and the translations' status. -One typically adds the following code to `templates/page.tmpl`: - - -
- -
- - -The following variables are available inside the loop (for every page in): - -- `URL` - url to the page -- `CODE` - two-letters language code -- `LANGUAGE` - language name (as defined in `po_slave_languages`) -- `MASTER` - is true (1) if, and only if the page is a "master" page -- `PERCENT` - for "slave" pages, is set to the translation completeness, in percents +An example of its use can be found in the default +`templates/page.tmpl`. In case you want to customize it, the following +variables are available inside the loop (for every page in): + +* `URL` - url to the page +* `CODE` - two-letters language code +* `LANGUAGE` - language name (as defined in `po_slave_languages`) +* `MASTER` - is true (1) if, and only if the page is a "master" page +* `PERCENT` - for "slave" pages, is set to the translation completeness, in percents ### Display the current translation status The `PERCENTTRANSLATED` variable is set to the translation -completeness, expressed in percent, on "slave" pages. - -One can use it this way: - - -
- -
- +completeness, expressed in percent, on "slave" pages. It is used by +the default `templates/page.tmpl`. Additional PageSpec tests ------------------------- @@ -194,14 +185,18 @@ Also, when the plugin has just been enabled, or when a page has just been declared as being translatable, the needed POT and PO files are created, and the PO files are checked into version control. -Discussion pages ----------------- +Discussion pages and other sub-pages +------------------------------------ Discussion should happen in the language in which the pages are written for real, *i.e.* the "master" one. If discussion pages are enabled, "slave" pages therefore link to the "master" page's discussion page. +Likewise, "slave" pages are not supposed to have sub-pages; +[[WikiLinks|wikilink]] that appear on a "slave" page therefore link to +the master page's sub-pages. + Translating ----------- @@ -211,118 +206,89 @@ interface could also be implemented at some point). If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's preferred `$EDITOR`, without needing to be online. +Markup languages support +------------------------ + +[[Markdown|mdwn]] is well supported. Some other markup languages supported +by ikiwiki mostly work, but some pieces of syntax are not rendered +correctly on the slave pages: + +* [[reStructuredText|rst]]: anonymous hyperlinks and internal + cross-references +* [[wikitext]]: conversion of newlines to paragraphs +* [[creole]]: verbatim text is wrapped, tables are broken +* [[html]] and LaTeX: not supported yet; the dedicated po4a modules + could be used to support them, but they would need a security audit +* other markup languages have not been tested. + +Security +======== + +[[po/discussion]] contains a detailed security analysis of this plugin +and its dependencies. + +When using po4a older than 0.35, it is recommended to uninstall +`Text::WrapI18N` (Debian package `libtext-wrapi18n-perl`), in order to +avoid a potential denial of service. + TODO ==== -Security checks ---------------- - -### Security history - -The only past security issues I could find in GNU gettext and po4a -are: - -- [CVE-2004-0966](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-0966), - *i.e.* [Debian bug #278283](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=278283): - the autopoint and gettextize scripts in the GNU gettext package - 1.14 and later versions, as used in Trustix Secure Linux 1.5 - through 2.1 and other operating systems, allows local users to - overwrite files via a symlink attack on temporary files. -- [CVE-2007-4462](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4462): - `lib/Locale/Po4a/Po.pm` in po4a before 0.32 allows local users to - overwrite arbitrary files via a symlink attack on the - gettextization.failed.po temporary file. - -**FIXME**: check whether this plugin would have been a possible attack -vector to exploit these vulnerabilities. - -Depending on my mood, the lack of found security issues can either -indicate that there are none, or reveal that no-one ever bothered to -find (and publish) them. - -### PO file features - -Can any sort of directives be put in po files that will cause mischief -(ie, include other files, run commands, crash gettext, whatever)? - -> No [documented](http://www.gnu.org/software/gettext/manual/gettext.html#PO-Files) -> directive is supposed to do so. - -### Running po4a on untrusted content - -Are there any security issues on running po4a on untrusted content? - -> To say the least, this issue is not well covered, at least publicly: -> -> - the documentation does not talk about it; -> - grep'ing the source code for `security` or `trust` gives no answer. -> -> I'll ask their opinion to the po4a maintainers. -> -> I'm not in a position to audit the code, but I had a look anyway: -> -> - no use of `system()`, `exec()` or backticks in `Locale::Po4a`; are -> there any other way to run external programs in Perl? -> - a symlink attack vulnerability was already discovered, so I "hope" -> the code has been checked to find some more already -> - the po4a parts we are using themselves use the following Perl -> modules: `DynaLoader`, `Encode`, `Encode::Guess`, -> `Text::WrapI18N`, `Locale::gettext` (`bindtextdomain`, -> `textdomain`, `gettext`, `dgettext`) -> -> --[[intrigeri]] - -### Fuzzing input - -I was not able to find any public information about gettext or po4a -having been tested with a fuzzing program, such as `zzuf` or `fusil`. -Moreover, some gettext parsers seem to be quite -[easy to crash](http://fusil.hachoir.org/trac/browser/trunk/fuzzers/fusil-gettext), -so it might be useful to bang gettext/po4a's heads against such -a program in order to easily detect some of the most obvious DoS. -[[--intrigeri]] - -gettext/po4a rough corners --------------------------- - -- fix infinite loop when synchronizing two ikiwiki (when checkouts - live in different directories): say bla.fr.po has been updated in - repo2; pulling repo2 from repo1 seems to trigger a PO update, that - changes bla.fr.po in repo1; then pushing repo1 to repo2 triggers - a PO update, that changes bla.fr.po in repo2; etc.; quickly fixed in - `629968fc89bced6727981c0a1138072631751fee`, by disabling references - in Pot files. Using `Locale::Po4a::write_if_needed` might be - a cleaner solution. -- new translations created in the web interface must get proper - charset/encoding gettext metadata, else the next automatic PO update - removes any non-ascii chars; possible solution: put such metadata - into the Pot file, and let it propagate; should be fixed in - `773de05a7a1ee68d2bed173367cf5e716884945a`, time will tell. - -Misc. improvements ------------------- - -### page titles - -Use nice page titles from meta plugin in links, as inline already -does. This is actually a duplicate for -[[bugs/pagetitle_function_does_not_respect_meta_titles]], which might -be fixed by something like [[todo/using_meta_titles_for_parentlinks]]. - -### source files format - -Markdown is supported, great, but what about others? The set of file -formats supported both in ikiwiki and po4a probably is greater than -`{markdown}`. - -Translation quality assurance ------------------------------ - -Modifying a PO file via the CGI must be forbidden if the new version -is not a valid PO file. As a bonus, check that it provides a more -complete translation than the existing one. - -A new `cansave` type of hook would be needed to implement this. - -Note: committing to the underlying repository is a way to bypass -this check. +Better links +------------ + +Once the fix to +[[bugs/pagetitle_function_does_not_respect_meta_titles]] from +[[intrigeri]]'s `meta` branch is merged into ikiwiki upstream, the +generated links' text will be optionally based on the page titles set +with the [[meta|plugins/meta]] plugin, and will thus be translatable. +It will also allow displaying the translation status in links to slave +pages. Both were implemented, and reverted in commit +ea753782b222bf4ba2fb4683b6363afdd9055b64, which should be reverted +once [[intrigeri]]'s `meta` branch is merged. + +An integration branch, called `meta-po`, merges [[intrigeri]]'s `po` +and `meta` branches, and thus has thise additional features. + +Robustness tests +---------------- + +### Enabling/disabling the plugin + +* enabling the plugin with `po_translatable_pages` set to blacklist: **OK** +* enabling the plugin with `po_translatable_pages` set to whitelist: **OK** +* enabling the plugin without `po_translatable_pages` set: **OK** +* disabling the plugin: **OK** + +### Changing the plugin config + +* adding existing pages to `po_translatable_pages`: **OK** +* removing existing pages from `po_translatable_pages`: **OK** +* adding a language to `po_slave_languages`: **OK** +* removing a language from `po_slave_languages`: **OK** +* changing `po_master_language`: **OK** +* replacing `po_master_language` with a language previously part of + `po_slave_languages`: needs two rebuilds, but **OK** (this is quite + a perverse test actually) + +### Creating/deleting/renaming pages + +All cases of master/slave page creation/deletion/rename, both via RCS +and via CGI, have been tested. + +### Misc + +* general test with `usedirs` disabled: **OK** +* general test with `indexpages` enabled: **not OK** +* general test with `po_link_to=default` with `userdirs` enabled: **OK** +* general test with `po_link_to=default` with `userdirs` disabled: **OK** + +Misc. bugs +---------- + +Documentation +------------- + +Maybe write separate documentation depending on the people it targets: +translators, wiki administrators, hackers. This plugin may be complex +enough to deserve this.