-- This script may be used with the auth-filter. Be sure to configure it as you wish.
--
-- Requirements:
-- luacrypto >= 0.3
-- <http://mkottman.github.io/luacrypto/>
--
--
--
-- Configure these variables for your settings.
--
--
local protected_repos = {
glouglou = { laurent = true, jason = true },
qt = { jason = true, bob = true }
}
local users = {
jason = "secretpassword",
laurent = "s3cr3t",
bob = "ilikelua"
}
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 password = users[post["username"]]
local redirect = validate_value(post["redirect"])
if redirect == nil then
not_found()
return 0
end
redirect_to(redirect)
-- Lua hashes strings, so these comparisons are time invariant.
if password == nil or password ~= post["password"] then
set_cookie("cgitauth", "")
else
-- One week expiration time
local username = secure_value(post["username"], os.time() + 604800)
set_cookie("cgitauth", username)
end
html("\n")
return 0
end
-- Returns 1 if the cookie is valid and 0 if it is not.
function authenticate_cookie()
accepted_users = protected_repos[cgit["repo"]]
if accepted_users == nil then
-- We return as valid if the repo is not protected.
return 1
end
local username = validate_value(get_cookie(http["cookie"], "cgitauth"))
if username == nil or not accepted_users[username:lower()] then
return 0
else
return 1
end
end
-- Prints the html for the login form.
function body()
html("<h2>Authentication Required</h2>")
html("<form method='post' action='")
html_attr(cgit["login"])
html("'>")
html("<input type='hidden' name='redirect' value='")
html_attr(secure_value(cgit["url"], 0))
html("' />")
html("<table>")
html("<tr><td><label for='username'>Username:</label></td><td><input id='username' name='username' autofocus /></td></tr>")
html("<tr><td><label for='password'>Password:</label></td><td><input id='password' name='password' type='password' /></td></tr>")
html("<tr><td colspan='2'><input value='Login' type='submit' /></td></tr>")
html("</table></form>")
return 0
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 url_decode(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(cookie)
local i = 0
local value = ""
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
value = component
elseif i == 1 then
expiration = tonumber(component)
if expiration == nil then
expiration = 0
end
elseif i == 2 then
salt = component
elseif i == 3 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", value .. "|" .. tostring(expiration) .. "|" .. salt, secret) then
return nil
end
if expiration ~= 0 and expiration <= os.time() then
return nil
end
return url_decode(value)
end
function secure_value(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)
authstr = 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
