From 7511f4b4df521656d422010b06e2b5b96b21eb84 Mon Sep 17 00:00:00 2001
From: Jason A. Donenfeld
Date: Tue, 10 Mar 2015 02:21:31 +0100
Subject: filters: Add sample gentoo script
---
filters/gentoo-ldap-authentication.lua | 320 +++++++++++++++++++++++++++++++++
1 file changed, 320 insertions(+)
create mode 100644 filters/gentoo-ldap-authentication.lua
(limited to 'filters')
diff --git a/filters/gentoo-ldap-authentication.lua b/filters/gentoo-ldap-authentication.lua
new file mode 100644
index 0000000..fce5632
--- /dev/null
+++ b/filters/gentoo-ldap-authentication.lua
@@ -0,0 +1,320 @@
+-- This script may be used with the auth-filter. Be sure to configure it as you wish.
+--
+-- Requirements:
+-- luacrypto >= 0.3
+--
+-- lualdap >= 1.2
+--
+--
+
+
+--
+--
+-- Configure these variables for your settings.
+--
+--
+
+-- A list of password protected repositories, with which gentooAccess
+-- group is allowed to access each one.
+local protected_repos = {
+ glouglou = "infra",
+ portage = "dev"
+}
+
+
+-- All cookies will be authenticated based on this secret. Make it something
+-- totally random and impossible to guess. It should be large.
+local secret = "BE SURE TO CUSTOMIZE THIS STRING TO SOMETHING BIG AND RANDOM"
+
+
+
+--
+--
+-- Authentication functions follow below. Swap these out if you want different authentication semantics.
+--
+--
+
+-- Sets HTTP cookie headers based on post and sets up redirection.
+function authenticate_post()
+ local redirect = validate_value("redirect", post["redirect"])
+
+ if redirect == nil then
+ not_found()
+ return 0
+ end
+
+ redirect_to(redirect)
+
+ local groups = gentoo_ldap_user_groups(post["username"], post["password"])
+ if groups == nil then
+ set_cookie("cgitauth", "")
+ else
+ -- One week expiration time
+ set_cookie("cgitauth", secure_value("gentoogroups", table.concat(groups, ","), os.time() + 604800))
+ end
+
+ html("\n")
+ return 0
+end
+
+
+-- Returns 1 if the cookie is valid and 0 if it is not.
+function authenticate_cookie()
+ local required_group = protected_repos[cgit["repo"]]
+ if required_group == nil then
+ -- We return as valid if the repo is not protected.
+ return 1
+ end
+
+ local user_groups = validate_value("gentoogroups", get_cookie(http["cookie"], "cgitauth"))
+ if user_groups == nil or user_groups == "" then
+ return 0
+ end
+ for group in string.gmatch(user_groups, "[^,]+") do
+ if group == required_group then
+ return 1
+ end
+ end
+ return 0
+end
+
+-- Prints the html for the login form.
+function body()
+ html("Gentoo LDAP Authentication Required
")
+ html("")
+
+ return 0
+end
+
+--
+--
+-- Gentoo LDAP support.
+--
+--
+
+local lualdap = require("lualdap")
+
+function gentoo_ldap_user_groups(username, password)
+ -- Ensure the user is alphanumeric
+ if username:match("%W") then
+ return nil
+ end
+
+ local who = "uid=" .. username .. ",ou=devs,dc=gentoo,dc=org"
+
+ local ldap, err = lualdap.open_simple {
+ uri = "ldap://ldap1.gentoo.org",
+ who = who,
+ password = password,
+ starttls = true,
+ certfile = "/var/www/uwsgi/cgit/gentoo-ldap/star.gentoo.org.crt",
+ keyfile = "/var/www/uwsgi/cgit/gentoo-ldap/star.gentoo.org.key",
+ cacertfile = "/var/www/uwsgi/cgit/gentoo-ldap/ca.pem"
+ }
+ if ldap == nil then
+ return nil
+ end
+
+ local group_suffix = ".group"
+ local group_suffix_len = group_suffix:len()
+ local groups = {}
+ for dn, attribs in ldap:search { base = who, scope = "subtree" } do
+ local access = attribs["gentooAccess"]
+ if dn == who and access ~= nil then
+ for i, v in ipairs(access) do
+ local vlen = v:len()
+ if vlen > group_suffix_len and v:sub(-group_suffix_len) == group_suffix then
+ table.insert(groups, v:sub(1, vlen - group_suffix_len))
+ end
+ end
+ end
+ end
+
+ ldap:close()
+
+ return groups
+end
+
+--
+--
+-- Wrapper around filter API, exposing the http table, the cgit table, and the post table to the above functions.
+--
+--
+
+local actions = {}
+actions["authenticate-post"] = authenticate_post
+actions["authenticate-cookie"] = authenticate_cookie
+actions["body"] = body
+
+function filter_open(...)
+ action = actions[select(1, ...)]
+
+ http = {}
+ http["cookie"] = select(2, ...)
+ http["method"] = select(3, ...)
+ http["query"] = select(4, ...)
+ http["referer"] = select(5, ...)
+ http["path"] = select(6, ...)
+ http["host"] = select(7, ...)
+ http["https"] = select(8, ...)
+
+ cgit = {}
+ cgit["repo"] = select(9, ...)
+ cgit["page"] = select(10, ...)
+ cgit["url"] = select(11, ...)
+ cgit["login"] = select(12, ...)
+
+end
+
+function filter_close()
+ return action()
+end
+
+function filter_write(str)
+ post = parse_qs(str)
+end
+
+
+--
+--
+-- Utility functions based on keplerproject/wsapi.
+--
+--
+
+function url_decode(str)
+ if not str then
+ return ""
+ end
+ str = string.gsub(str, "+", " ")
+ str = string.gsub(str, "%%(%x%x)", function(h) return string.char(tonumber(h, 16)) end)
+ str = string.gsub(str, "\r\n", "\n")
+ return str
+end
+
+function url_encode(str)
+ if not str then
+ return ""
+ end
+ str = string.gsub(str, "\n", "\r\n")
+ str = string.gsub(str, "([^%w ])", function(c) return string.format("%%%02X", string.byte(c)) end)
+ str = string.gsub(str, " ", "+")
+ return str
+end
+
+function parse_qs(qs)
+ local tab = {}
+ for key, val in string.gmatch(qs, "([^&=]+)=([^&=]*)&?") do
+ tab[url_decode(key)] = url_decode(val)
+ end
+ return tab
+end
+
+function get_cookie(cookies, name)
+ cookies = string.gsub(";" .. cookies .. ";", "%s*;%s*", ";")
+ return string.match(cookies, ";" .. name .. "=(.-);")
+end
+
+
+--
+--
+-- Cookie construction and validation helpers.
+--
+--
+
+local crypto = require("crypto")
+
+-- Returns value of cookie if cookie is valid. Otherwise returns nil.
+function validate_value(expected_field, cookie)
+ local i = 0
+ local value = ""
+ local field = ""
+ local expiration = 0
+ local salt = ""
+ local hmac = ""
+
+ if cookie == nil or cookie:len() < 3 or cookie:sub(1, 1) == "|" then
+ return nil
+ end
+
+ for component in string.gmatch(cookie, "[^|]+") do
+ if i == 0 then
+ field = component
+ elseif i == 1 then
+ value = component
+ elseif i == 2 then
+ expiration = tonumber(component)
+ if expiration == nil then
+ expiration = -1
+ end
+ elseif i == 3 then
+ salt = component
+ elseif i == 4 then
+ hmac = component
+ else
+ break
+ end
+ i = i + 1
+ end
+
+ if hmac == nil or hmac:len() == 0 then
+ return nil
+ end
+
+ -- Lua hashes strings, so these comparisons are time invariant.
+ if hmac ~= crypto.hmac.digest("sha1", field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt, secret) then
+ return nil
+ end
+
+ if expiration == -1 or (expiration ~= 0 and expiration <= os.time()) then
+ return nil
+ end
+
+ if url_decode(field) ~= expected_field then
+ return nil
+ end
+
+ return url_decode(value)
+end
+
+function secure_value(field, value, expiration)
+ if value == nil or value:len() <= 0 then
+ return ""
+ end
+
+ local authstr = ""
+ local salt = crypto.hex(crypto.rand.bytes(16))
+ value = url_encode(value)
+ field = url_encode(field)
+ authstr = field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt
+ authstr = authstr .. "|" .. crypto.hmac.digest("sha1", authstr, secret)
+ return authstr
+end
+
+function set_cookie(cookie, value)
+ html("Set-Cookie: " .. cookie .. "=" .. value .. "; HttpOnly")
+ if http["https"] == "yes" or http["https"] == "on" or http["https"] == "1" then
+ html("; secure")
+ end
+ html("\n")
+end
+
+function redirect_to(url)
+ html("Status: 302 Redirect\n")
+ html("Cache-Control: no-cache, no-store\n")
+ html("Location: " .. url .. "\n")
+end
+
+function not_found()
+ html("Status: 404 Not Found\n")
+ html("Cache-Control: no-cache, no-store\n\n")
+end
--
cgit v1.2.3-70-g09d2