-- This script may be used with the auth-filter. Be sure to configure it as you wish.
--
-- Requirements:
-- luacrypto >= 0.3
--
--
--
--
-- Configure these variables for your settings.
--
--
-- A list of password protected repositories along with the users who can access them.
local public_repos = {
vimwiki = true
}
-- Please note that, in production, you'll want to replace this simple lookup
-- table with either a table of salted and hashed passwords (using something
-- smart like scrypt), or replace this table lookup with an external support,
-- such as consulting your system's pam / shadow system, or an external
-- database, or an external validating web service. For testing, or for
-- extremely low-security usage, you may be able, however, to get away with
-- compromising on hardcoding the passwords in cleartext, as we have done here.
local users = {
hugo = "password"
}
-- All cookies will be authenticated based on this secret. Make it something
-- totally random and impossible to guess. It should be large.
local secret = "Ianae4woof3ial9ahdahng7ahth9yoo2ri6zuw7eeYaengai0s"
--
--
-- Authentication functions follow below. Swap these out if you want different authentication semantics.
--
--
function printenv(arg)
local keys = {
"CGIT_CONFIG",
"CGIT_REPO_URL", "CGIT_REPO_NAME", "CGIT_REPO_PATH",
"CGIT_REPO_OWNER", "CGIT_REPO_GROUP", "CGIT_REPO_DEFBRANCH",
"CGIT_REPO_SECTION", "CGIT_REPO_CLONE_URL",
"GIT_REPO", "GIT_CONFIG_NOSYSTEM",
"GIT_ATTR_NOSYSTEM",
"GIT_DIR", "GIT_CONFIG_NOSYSTEM", "GIT_ATTR_NOSYSTEM",
"QUERY_STRING"
}
-- print "!!!"
-- html ("!!!")
-- print ("
body
Key | Value |
")
io.stderr:write(os.time(os.date("!*t")))
io.stderr:write("\n")
io.stderr:write(arg);
for _, attr in pairs(keys) do
local l = os.getenv(attr)
-- print("" )
---print (attr)
-- print (" | ")
-- print (l)
-- print(" |
")
io.stderr:write(attr)
io.stderr:write(" = " )
if l == nil then
io.stderr:write("nil");
else
io.stderr:write(l)
end
io.stderr:write("\n")
end
-- print ("
")
end
-- Sets HTTP cookie headers based on post and sets up redirection.
-- TODO this tries to authenticate on the root page (good), but fails to set
-- the cookie. I think it gets stuck in the redirect filter (bad).
-- TODO invalid login also kinda breaks the page... Not found should return the
-- user to the login page with an error messsage displaed.
function authenticate_post()
printenv("Authenticate Post\n=================\n");
local password = users[post["username"]]
local redirect = validate_value("redirect", 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("username", 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()
printenv("Authenticate Cookie\n===================\n");
-- accepted_users = protected_repos[cgit["repo"]]
if public_repos[cgit["repo"]] then
-- We return as valid if the repo is not protected.
return 1
end
local username = validate_value("username", get_cookie(http["cookie"], "cgitauth"))
-- if username == nil or not accepted_users[username:lower()] then
if username == nil then
return 0
else
return 1
end
end
-- Prints the html for the login form.
function body()
printenv("Body\n====\n");
html("New login form!
");
html("But still don't contact me to gain access.
");
html("Authentication Required
")
html("")
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(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