-- 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. -- -- -- A list of password protected repositories along with the users who can access them. local protected_repos = { glouglou = { laurent = true, jason = true }, qt = { jason = true, bob = 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 = { jason = "secretpassword", laurent = "s3cr3t", bob = "ilikelua" } -- 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 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