+-- 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
+function authenticate_post()
+ local password = users[post["username"]]
+ -- TODO: Implement time invariant string comparison function to mitigate against timing attack.
+ if password == nil or password ~= post["password"] then
+ construct_cookie("", "cgitauth")
+ else
+ construct_cookie(post["username"], "cgitauth")
+ end
+ 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_cookie(get_cookie(http["cookie"], "cgitauth"))
+ if username == nil or not accepted_users[username] 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("<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
+
+
+--
+--
+-- Cookie construction and validation helpers.
+--
+--
+
+local crypto = require("crypto")
+
+-- Returns username of cookie if cookie is valid. Otherwise returns nil.
+function validate_cookie(cookie)
+ local i = 0
+ local username = ""
+ local expiration = 0
+ local salt = ""
+ local hmac = ""
+
+ if cookie:len() < 3 or cookie:sub(1, 1) == "|" then
+ return nil
+ end
+
+ for component in string.gmatch(cookie, "[^|]+") do
+ if i == 0 then
+ username = 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
+
+ -- TODO: implement time invariant comparison to prevent against timing attack.
+ if hmac ~= crypto.hmac.digest("sha1", username .. "|" .. tostring(expiration) .. "|" .. salt, secret) then
+ return nil
+ end
+
+ if expiration <= os.time() then
+ return nil
+ end
+
+ return username:lower()
+end
+
+function construct_cookie(username, cookie)
+ local authstr = ""
+ if username:len() > 0 then
+ -- One week expiration time
+ local expiration = os.time() + 604800
+ local salt = crypto.hex(crypto.rand.bytes(16))
+
+ authstr = username .. "|" .. tostring(expiration) .. "|" .. salt
+ authstr = authstr .. "|" .. crypto.hmac.digest("sha1", authstr, secret)
+ end
+
+ html("Set-Cookie: " .. cookie .. "=" .. authstr .. "; HttpOnly")
+ if http["https"] == "yes" or http["https"] == "on" or http["https"] == "1" then
+ html("; secure")
+ end
+ html("\n")
+end
+
+--
+--
+-- Wrapper around filter API follows below, 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"] = ""
+ for _ in cgit["url"]:gfind("/") do
+ cgit["login"] = cgit["login"] .. "../"
+ end
+ cgit["login"] = cgit["login"] .. "?p=login"
+
+end
+
+function filter_close()
+ return action()
+end
+
+function filter_write(str)
+ post = parse_qs(str)
+end
+
+
+--
+--
+-- Utility functions follow below, 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 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
projects / ps-cgit / commitdiff