the
introduction
The
To use
apt install python3-markdown python3-whoosh python3-passlib python3-bleach python3-pyqrcode \
python3-pil python3-natsort python3-ldap
local installation
koi.zip and type cd koi. The file config.py contains detailed explanations of all configuration options and should be reviewed. In particular session_cookie_sig must be set. Once this is done, running ./koi.py will make this tutorial accessible at http://localhost:8080.
serving files
By default web pages are in the pages directory. To create a new web page first make a sub-directory test (a page in koi directory:
mkdir pages/test
cp logo.txt pages/test
The file is now located at http://localhost:8080/pages/test/logo.txt but clicking the link will complain about a missing .koi file and return a 403 error. In order to serve requests every page must have an associated template in the dir_templates directory. Which template is used is determined by the name of a JSON .koi file inside the web page directory so that, for example, article.koi will use the template file article.tpl. The most basic template is files.tpl and the simplest document possible is storing the string {} into a file called files.koi within test/ as so:
echo '{}' > pages/test/files.koi
Once this is done the files.tpl template will be used to serve the logo.txt file which can now be retrieved by clicking the link above. Note that, for extra security, the directive force_acl can be set to True in config.py, in which case all pages (other than login.koi) must have a properly-defined ACL if they are to be served. If that's the case the above command should be replaced by:
echo '{"acl": {"files.koi": {"users": "*", "groups": [], "ips": "*", "time": 0}}}' > pages/test/files.koi
creating a web page
Although the files inside test can be now served, the web page http://localhost:8080/pages/test itself is empty. The files.tpl template can display the contents of a key called body, so replacing the empty JSON object with {"body": "Hello world!"} in files.koi will now show a "Hello world" web page at the above link:
echo '{"body": "Hello world!"}' >! pages/test/files.koi
Editing JSON files is not very practical and so koiedit.py script by simply creating a directory (i.e. page/slug) with the appropriate apache server access permissions and running (if in the
mkdir pages/<slug>
./koiedit.py pages/<slug>/article.koi
./koiacl.py pages/<slug>/article.koi
Also included is the html2koi.py script, which allows to convert existing HTML files into .koi format.
searching
The default search engine is powered by whoosh which is a non-standard but readily-available module which might be have to be installed (as root), as well as markdown in order to parse most pages:
apt install python3-markdown python3-whoosh
Main features of the search function are:
- query words can be separated by
AND(the default),OR,NOT,ANDNOTandANDMAYBE - fuzzy queries e.g.
grafiti~will findgraffiti(see more) - phrase search using double quotes
- field searches on
title,body,keywords,author, andcreator
A complex search could be crafted as follows:
author:yuma OR grafiti~ ANDNOT title:lavender
The index is dynamically updated any time a new article or page is added, deleted, or modified. Note that both this and the simple search engine (see below) filter their results based on access control lists (ACLs) so that matches of restricted pages are not shown unless the user (or visitor) performing the search has access to them.
Only the title, body, keywords, author, and creator fields of .koi files are indexed. Thus, a text file upload paper.txt will not be found in a search even if a keyword matches within. Furthermore, the index will only be updated if a .koi file timestamp field has been properly set. The search index can be regenerated at any time by deleting the cache (stored in search/.index by default).
adding users
The basic functionality for creating websites through the back-end is to simply write templates and add content via their corresponding .koi JSON file. A simpler approach is to use the built-in article editor. However, in order to do so users must be added to the system. Note that this requires passlib so running apt install python3-passlib may be necessary, and if using LDAP then apt install python3-ldap.
For increased security all user management is deliberately done from the back-end, although a template could in principle be written to accomplish this through a web page. Running the script koiaccts.py offers a simple menu-driven command-line interface which allows, amongst other things, searching, adding, deleting, listing, and modifying user accounts:
# ./koiaccts.py
koi account manager (use "-h" for non-interactive usage)
========================================================
0) Search
1) Add account
2) Remove account
3) Modify account
4) List users/account
5) Batch import
6) Exit
Of note is the fact that the hashing algorithm is compatible with the Linux /etc/shadow file, and thus offers the possibility of importing existing user accounts (though only SHA512 and yescrypt are allowed). User accounts are stored in JSON files inside the directory specified by dir_accounts_fp in config.py so it's important to review this setting before proceeding. The following settings should also be revised in config.py: wwwuid and wwwgid, corresponding to the user the web server runs as, and wwwfperms and wwwdperms, corresponding to the permissions files and directories should have so that the web server user (and preferably no one else) can access them (note that changing ownership will only work if running the script as the superuser). The koiaccts.py script can also be run non-interactively as shown below.
# ./koiaccts.py -h
usage: koiaccts.py [-h] [-a] [-d] [-e] [-xe] [-fn FIRSTNAME]
[-g [GROUP [GROUP ...]]] [-G [AGROUP [AGROUP ...]]]
[-ln LASTNAME] [-L] [-m TWOF_EMAIL] [-mn MIDDLENAME]
[-n NAME] [-o] [-p PASSWORD] [-pa PRIMARY_ADDRESS]
[-pe PRIMARY_EMAIL] [-pp PRIMARY_PHONE] [-q]
[-s [SHOW [SHOW ...]]] [-t] [-xt] [-u USER] [-U] [-w]
optional arguments:
-h, --help show this help message and exit
-a, --add add new user
-d, --delete delete user (will back-up account)
-e, --editor_on enable editor role
-xe, --editor_off disable editor role
-fn FIRSTNAME, --firstname FIRSTNAME
user's first name
-g [GROUP [GROUP ...]], --group [GROUP [GROUP ...]]
set groups (space-separated list, none to empty)
-G [AGROUP [AGROUP ...]], --agroup [AGROUP [AGROUP ...]]
add groups (space-separated list)
-ln LASTNAME, --lastname LASTNAME
user's last name
-L, --lock lock account
-m TWOF_EMAIL, --twof_email TWOF_EMAIL
set two-factor email address
-mn MIDDLENAME, --middlename MIDDLENAME
user's middle name(s)
-n NAME, --name NAME set name (construct using "fn"/"mn"/"ln" otherwise)
-o, --overview overview of all accounts
-p PASSWORD, --password PASSWORD
set password (using hash)
-pa PRIMARY_ADDRESS, --primary_address PRIMARY_ADDRESS
set user's primary address
-pe PRIMARY_EMAIL, --primary_email PRIMARY_EMAIL
set user's primary email
-pp PRIMARY_PHONE, --primary_phone PRIMARY_PHONE
set user's primary phone
-q, --quiet quiet mode
-s [SHOW [SHOW ...]], --show [SHOW [SHOW ...]]
show profile keys (list, none for all)
-t, --twof_on enable multi-factor
-xt, --twof_off disable multi-factor
-u USER, --user USER user name
-U, --unlock unlock account
-w, --wipe wipe out user account
Adding an account is straightforward and can be done following the steps set by the script. User names are case-insensitive and restricted by the user_re configuration setting, which by default allows alphanumeric strings and email addresses in any language (so that "AIKA", "sora@remeika.ca", and "ゆま" are all valid, albeit not necessarily a prudent mix). If desired an email for two-factor authentication may be set, but care must be taken to configure the format of the message (twoF_msg) and SMTP settings in config.py. Finally, starting with config.py, bypassing the local password database.
Listing a user's profile via koiaccts.py shows the basic structure of the account and some information about their last login, logout, IP used, "locked" status, roles, and groups they belong to. Note that "roles" consists of lists that can be assigned on a per-template basis, and so having the "editor" role for the "edit" template allows authoring articles via the web browser as explained later on.
multi-factor authentication
koiaccts.py interactively and selecting:
3) Modify account -> 6) Set/render two-factor TOTP (time-based one-time password)
at which point a QR image is generated (on the terminal), together with a non-graphical code in case the user does not have a camera.
Other mitigation measures against brute-force login attempts can be implemented through both rate-limiting and attempt-limiting throttlers. For details refer to the settings throttle_delay, throttle_attempts, and throttle_lockout detailed in config.py.
editing articles
By default koiaccts.py). Note that the editor requires the bleach module to operate so apt install python3-bleach may be necessary.
Once a user has been created they can log in at http://localhost:8080/pages/login. After authenticating users can click on the article.tpl or gallery.tpl templates are supported:
The editor is mostly self-explanatory. Articles are written in markdown (help for which is available from the collapsed section at the bottom of the editing page) and consist of a title, a slug (see below), a space-separated list of keywords, and a body (most elements will provide a helpful pop-up if hovered on). Controls for editing an article are:
webpage opens the current web page in a new tab (must be refreshed after saving edits)
files file manager to review and delete files, and also manage ACLs (see below)
uploader for uploading files unto the web page
articles to return to the article listing
save to save the current article
Files (including images) can be linked and embedded in web pages using markdown syntax (the file manager provides the link/embed code for each file which can be copied and pasted into the article):
By default web pages are stored in directories named after the creation time-stamp e.g. /pages/1593798867, but can be renamed using the slug field after first saved. All article revisions are stored in hidden files as .article.koi-rev# (where rev# is the revision number) within the page directory, so it's feasible to recover prior versions (though only from the back-end). Deleted articles and their files are also backed-up as hidden directories (e.g. /pages/.name-rev#-timestamp), although individually-deleted files are permanently removed.
curating a gallery
Note: Ubuntu versions prior to 22.04 use an older version of PIL (ver. 7 vs ver. 9). If running on Ubuntu >= 22.04 please download gallery.tpl.pil9 and replace gallery.tpl in the templates directory with the newer version.
The editor offers a second function: that of creating image galleries. This feature requires PIL, and optionally natsort, and hence apt install python3-pil python3-natsort may be necessary. The default image formats supported are .jpg and .png.
As with articles, galleries have a title, a slug, and keywords. Two viewing modes are available, grid (overview of the entire image set) and slide (single picture view, with a
By default a new gallery has the same curator (editor) and ACL permissions as new articles i.e. it's restricted to the user who created it.
After creating a new gallery images can be uploaded to the page when in grid view. The ACL (see next section) of individual images can only be set from the back-end, but a show/hide mechanism is available. When an image is uploaded it is automatically tagged as hidden (this can be changed by changing the hide_new parameter under def_image to False in edit.koi). In grid and slide views these images look slightly washed-out to the curator, and visitors will need to append a tag e.g. ?unhide at the end of the gallery URL to view them. A toggle button can be found under each image in slide view, and so a curator can control what images are always shown and which ones require the special URL. The tag is configurable in edit.koi from the back-end by editing the unhide_tag setting. Keep in mind that hiding images does not block a direct link to the image file (an ACL would be needed for that), but it provides a simple filter depending on the link followed to the gallery. As explained in the "scripts and back-end usage" section below both articles and galleries can be manipulated from a command-line terminal, so management via the GUI is completely optional and can even be disabled for enhanced security.
The last feature of the editor is ACL manipulation, explained in the section below.
access control lists (acls)
Articles and galleries have two types of restrictions: who can edit/curate them and who can view them. Newly-created articles and galleries can only be modified and viewed by their original author, but other editors can be added by clicking on the ▸ Access control list for <name> (or ▸ gallery ACL in grid view) expandable section and modifying the list of users who can edit the page (note that it's impossible to remove oneself). Adding a wildcard * allows any logged-in user to edit the article/gallery. ACL controls for articles and galleries are equivalent, so any reference to articles below applied also to galleries.
The access control list for viewing articles can restrict access to web pages and files on a per-user, per-IP, and date-time basis (per-group is also supported but only through the back-end). This limits who can view a web page or download a file when clicking on a link. By default new articles can only be accessed by the user who originally wrote them, from any IP, starting from the creation date-time. To make an article universally available suffice to make the user ACL equal to *, the IP ACL equal to *, and leave the timestamp as-is. Other ACL features are:
- Adding a
*to the user list will give access permissions to all logged-in users - Subnets (possibly in combination with an IP address list) can be specified as
xxx.yyy - Setting a future release date will only allow access from that date-time onward
- To block, prepend
!to a user or IP/subnet (overrides any conflicting allow directive)
Access control lists can be manipulated in exactly the same way from the file manager on a per-file basis (by default uploaded files inherit the ACL of the web page). Galleries only offer a per-image ACL via the back-end.
trusted articles, making forms
To thwart XSS attacks user input is sanitized using bleach and context-based allowlists, and further escaped upon display unless used in an HTML context. This, however, strips most HTML code which is sometimes undesirable. trusted to True in the .koi file, which in turn will add the tag "(
Forms can then be included in templates as well as trusted .koi files (or .html files converted using html2koi.py).
For example, the code to add a search field to an article is:
<form action="/pages/search" method="post">
{{!×CSRF}}
<input name="search_query" size="12" type="text">
<button class="button" type="submit">search</button>
</form>
depending on how various variables have been defined in config.py i.e. search_query is actually the value of CONFIG['search_var'] (note that "x" has been replaced with "×" for the anti-CSRF variable name, otherwise it'd be replaced in the snippet above). The anti-CSRF measure must be coded in the template, which in the case of article.tpl is done as so:
% if user := PROFILE.get('user', ''):
% xCSRF = f'<input name="xCSRF" type="hidden" value="{PROFILE["xCSRF"]}">'
% else:
% xCSRF = ''
% end
% content = PAGE['body'].replace('{{!×CSRF}}', xCSRF)
templates
templates directory (configurable via dir_templates) which can be studied for reference. Other than the special login.tpl, all templates are provided the following dictionaries:
BOTTLEthe WSGI environment
CONFIGall parameters defined in
config.pyFORMSall form values, decoded
INDEXthe website index, each key being the
pagename and the corresponding.koidataMEproperties of the current page
PAGEthe
.koiJSON dictionaryPROFILEthe current user's JSON profile (an empty dictionary if no session is ongoing)
QUERYthe combined
GETandPOSTdictionary, decodedTREEthe website tree, each key being the
pagename with the equivalentMEdictionaryUPLOADa dictionary of uploaded files (with number keys
0up toupload_max_files)USERSoverview of all users, each key being a user name and its
PROFILEdictionary
The main difference between FORMS and QUERY is that the latter returns a dictionary with
one key per form input while the former retrieves a FormsDict which can contain repeated
keys with different values as a list (resulting, for example, from a selector element, or multiple checkboxes).
A form with an input named animal can have its value retrieved as so:
QUERY['animal'] (returns lion)
while the input from a selector element named colours can be obtained as so:
FORMS.getall('colours') (returns ['red', 'green', 'yellow'])
Detailed dictionary keys:
MEcontains the following (example shown):page:mainpath:/www/koi/pages/mainkoi_fp:/www/koi/pages/main/article.koitemplate:articleuri:/pages/mainfiles:['article.koi', 'image.jpg']
PROFILEcontains the following (example shown, extensible entries may have further keys added):- id-related:
user:yumauid:1c3859d413c83abcc2bc4f4c9a6d5a12groups:['s1', 'alice']full_name:{'first': 'Yuma', 'last': 'Asami', 'middle': ''}(extensible)name:Yuma Asamiemail:{'primary': 'yuma@ebisumuscats.org'}(extensible)phone:{'primary': '555-555-5555'}(extensible)address:{'primary': '8-909 Somewhere in Tokyo'}(extensible)gecos:Yuma Asami,,,roles:{'edit': ['editor']}(extensible)
- authentication-related:
hash:$6$...(hash string)multiF_check:{"enabled": true,"twoF_email": "yuma@ebisumuscats.net", "twoF_totp": {TOTP dict}}
- session-related:
ip: (IP address)token: (token string)nonce: (integer value)xCSRF: (anti-CSRF string)login_ts: (epoch timestamp)logout_ts: (epoch timestamp)knock_tss: (epoch timestamp list)created: (epoch timestamp)locked: (boolean)
- misc:
koi_version:0.34
- unused:
cache: (dictionary)data: (dictionary)
- id-related:
TREE[page]contains the following keys (which matchME):pathtemplateurifilesserve: (boolean specifying whetherpagecan be served)
UPLOAD[N]contains the following keys:OK: (boolean depending of whether the upload was successful)status: (upload status e.g. "upload successful")content_type: (e.g. "application/zip")raw_filename: (original filename, potentially dangerous)safe_name: (safe filename adequate for local storage)file_data: (the upload data)
USERS[user]same as
PROFILE
Note that for performance reasons INDEX and TREE are only provided if get_index is set to True in the .koi file, and similarly USERS is only provided if get_users is also True. Otherwise the dictionaries are present but empty (as is UPLOAD if no uploads are found). User names have their case preserved, but should be lower-cased for internal usage in templates if trying to recreate the account's JSON record name (uid) i.e. use user.lower().
uploads
The following code adds an upload form/button in a template (note that the name of the upload input must be koi_file_upload, while the operation/save_upload hidden input is an example of the action the template needs to perform in order to save the upload):
<form id="upload" action="{{ME['uri']}}" enctype="multipart/form-data" method="post">
<input type="hidden" name="operation" value="save_upload">
{{!×CSRF}}
</form>
<input form="upload" name="koi_file_upload" type="file" multiple>
<button form="upload" type="submit">upload</button>
Uploads are stored in an UPLOAD dictionary with numerical entries UPLOAD[0], UPLOAD[1] ... UPLOAD[config.upload_max_files-1]. They can be stored via a template using the following code (i.e. what the template should do if QUERY['operation'] == 'save_upload' in the above example):
% for key, up in UPLOAD.items():
% if up['OK']:
% with open(os.path.join(ME['path'], up['safe_name']), 'wb') as fd:
% fd.write(up['file_data'])
% end
% end
% end
Change ME['path'] to save the file in a different directory, and check for I/O errors as needed. Note that files with a .koi extension will have a safe name .koi.up extension instead.
scripts and back-end usage
As mentioned earlier in this guide, koi directory:
koiaccts.pymanage user accounts (use "-h" for non-interactive usage)
koiacl.pymanipulate the access control list of a page
html2koi.pyconvert an HTML file into an
article.koifilekoiedit.pyedit the contents of a
.koifile using a text editorkoiport.pycreate a
gallery.koiorshowcase.koifile
For example, to create a new gallery from the back-end the following procedure would be followed (starting from the koi directory). First, create the gallery:
./koiport.py
Set proper ACL permissions:
./koiacl.py
Move gallery.koi to its page directory and populate the gallery (make sure the directory and files therein are accessible to the web server i.e. proper ownership and read/write/execute permissions):
mkdir pages/portfolio
mv gallery.koi pages/portfolio
cp -p /mnt/camera/*.jpg pages/portfolio/
Upon visiting the page for the first time at http://localhost:8080/pages/portfolio (append ?tag if created with a hide-by-default tag) the gallery will automatically be generated. It can then be updated if images are added or deleted, either via the web interface or cp at the command-line.
apache configuration
To run
apt install libapache2-mod-wsgi-py3
Assuming a working SSL-enabled web server is already running, the first step is to move the koi directory into a suitable location, say /www/wsgi, and modify the file koi.wsgi to set sys.path accordingly e.g.
sys.path = ['/www/wsgi/koi/'] + sys.path
Ownership (perhaps www-data) and permissions of files (600) and directories (700) should be reviewed, as should the settings in config.py, particularly dir_accounts_fp (say, /usr/local/etc) and a new session_cookie_sig. Setting force_ssl to True is highly recommended, and care should be taken not to run in DEBUG mode.
Adding the following code to an ssl VirtualHost may then suffice:
DocumentRoot /www/wsgi/koi
<Directory /www/wsgi/koi>
Options None
AllowOverride None
Require all granted
</Directory>
WSGIProcessGroup koi
WSGIDaemonProcess koi user=www-data group=www-data
WSGIScriptAlias / /www/wsgi/koi/koi.wsgi
Remember to touch koi.wsgi after adding a new template or making changes to existing ones in order to update the cache.
odds and ends
page_login is set to in config.py):
mv pages/login pages/.login
and then editing config.py appropriately e.g. page_login='.login'. Editing and searching can also be disabled in a similar manner (note that login, edit, and search can each be toggled this way independently of each other).
?foo=bar&ham=spam) except for the following which are reserved for internal usage: koi_wants, koi_stay, user, password, koi_session, nonce, and xCSRF (in other words, the query ?user=jane will be removed from the redirect).
config.py: r'^[a-zA-Z0-9][a-zA-Z0-9_-]{0,75}$'. This allows for a mix of up to seventy-six underscores, dashes, and alphanumeric ASCII characters. This rule is not enforced by the edit.tpl. Another example which disallows some misleading page names could be r'(?i)^(?!home|download|admin)[a-z0-9][a-z0-9_-]{0,75}$'.
ssearch.tpl and the more advanced wsearch.tpl. Which one is used is a simple matter of making a symlink of the preferred template file to search.tpl. The simple search engine has no external dependencies and requires no index, but does no more than a case-insensitive AND search of the submitted words with no concept of query analysis or scoring. The whoosh-based engine wsearch.tpl is the default.
error.tpl template, in particular the following snippet:
% if CODE in [400, 403, 404, 413, 500]:
<p><font class="error">[{{CODE}}] {{DETAILS}}</font></p>
% end
can be customized as desired (by, say, getting rid of {{DETAILS}} in extreme cases).
.koi files can always be (carefully) edited directly using a text editor, or from within the python interpreter (but care must be taken not to delete standard fields which may be required by the editor):
import json
with open("pages/article/article.koi", "r") as fd:
artdata = json.load(fd)
... do stuff to "artdata" ...
with open("pages/article/article.koi", "w") as fd:
json.dump(artdata, fd, ensure_ascii=False)
.koi files (article files in particular) is to use the included koiedit.py script. The editor of choice can be set via the EDITOR variable at the top of the script. The default value is emacs -nw, which combined with the "Save Place" directive ((save-place-mode 1) in the .emacs file) allows to conveniently cycle between editing, saving/quitting, and reloading the file in a browser. The koiedit.py command can take the .koi file as an argument.
{"article.koi":{"users": "*", "groups": [], "ips": "*", "time": 0},
"araara.doc": {"users": ["クレア"], "groups": [], "ips": ["8.8.8.8"], "time": 0}
"kira.tex": {"users": ["AIKA"], groups: ["av"], "ips": ["128.100"], "time": 0}
"SAbday.pdf": {"users": ["yuma", "!sora"], "groups": ["sod"], "ips": "*", "time": 0}
"ntr.ppt": {"users": [], "groups": ["tissue"], "ips": "*", "time": 0}
"shibu.jpg": {"users": ["*"], "groups": ["!moodyz"], "ips": "*", "time": 1604973574}}
- The contents of
article.koiare available to all. - The file
araara.docis available to クレア as long as she accesses it from the IP address 8.8.8.8. - The file
kira.texis available to AIKA and everyone in the av group as long as they do so from the 128.100 subnet. - The file
SAbday.pdfis available to user "yuma" and the members of group "sod", but not to "sora". - The file
ntr.pptis only available to members of group "tissue". - The file
shibu.jpgcan be downloaded by any logged-in user who does not belong to themoodyzgroup after the epoch time1604973574(2020-11-10T01:59:34+00:00).
These ACLs are not exclusive to articles and can be applied to any web page regardless of the template (other than the login page which has no ACL enforcement). It's a good idea, however, to make the location corresponding to page_assets (which contains css files and the such) available to all. The lack of an ACL entry in the .koi file is equivalent to making the web page and its files available to anyone unless force_acl is set to True.
colophone
bottle is distributed under the MIT license
CSS used is a customized version of skeleton, distributed under the MIT license
The
