auth-filters: add simple file-based authentication scheme
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld
vanhempi
82856923bf
commit
77b6f83344
352
filters/file-authentication.lua
Normal file
352
filters/file-authentication.lua
Normal file
@ -0,0 +1,352 @@
|
||||
-- This script may be used with the auth-filter.
|
||||
--
|
||||
-- Requirements:
|
||||
-- luacrypto >= 0.3
|
||||
-- <http://mkottman.github.io/luacrypto/>
|
||||
-- luaposix
|
||||
-- <https://github.com/luaposix/luaposix>
|
||||
--
|
||||
local sysstat = require("posix.sys.stat")
|
||||
local unistd = require("posix.unistd")
|
||||
local crypto = require("crypto")
|
||||
|
||||
|
||||
-- This file should contain a series of lines in the form of:
|
||||
-- username1:hash1
|
||||
-- username2:hash2
|
||||
-- username3:hash3
|
||||
-- ...
|
||||
-- Hashes can be generated using something like `mkpasswd -m sha-512 -R 300000`.
|
||||
-- This file should not be world-readable.
|
||||
local users_filename = "/etc/cgit-auth/users"
|
||||
|
||||
-- This file should contain a series of lines in the form of:
|
||||
-- groupname1:username1,username2,username3,...
|
||||
-- ...
|
||||
local groups_filename = "/etc/cgit-auth/groups"
|
||||
|
||||
-- This file should contain a series of lines in the form of:
|
||||
-- reponame1:groupname1,groupname2,groupname3,...
|
||||
-- ...
|
||||
local repos_filename = "/etc/cgit-auth/repos"
|
||||
|
||||
-- Set this to a path this script can write to for storing a persistent
|
||||
-- cookie secret, which should not be world-readable.
|
||||
local secret_filename = "/var/cache/cgit/auth-secret"
|
||||
|
||||
--
|
||||
--
|
||||
-- Authentication functions follow below. Swap these out if you want different authentication semantics.
|
||||
--
|
||||
--
|
||||
|
||||
-- Looks up a hash for a given user.
|
||||
function lookup_hash(user)
|
||||
local line
|
||||
for line in io.lines(users_filename) do
|
||||
local u, h = string.match(line, "(.-):(.+)")
|
||||
if u:lower() == user:lower() then
|
||||
return h
|
||||
end
|
||||
end
|
||||
return nil
|
||||
end
|
||||
|
||||
-- Looks up users for a given repo.
|
||||
function lookup_users(repo)
|
||||
local users = nil
|
||||
local groups = nil
|
||||
local line, group, user
|
||||
for line in io.lines(repos_filename) do
|
||||
local r, g = string.match(line, "(.-):(.+)")
|
||||
if r == repo then
|
||||
groups = { }
|
||||
for group in string.gmatch(g, "([^,]+)") do
|
||||
groups[group:lower()] = true
|
||||
end
|
||||
break
|
||||
end
|
||||
end
|
||||
if groups == nil then
|
||||
return nil
|
||||
end
|
||||
for line in io.lines(groups_filename) do
|
||||
local g, u = string.match(line, "(.-):(.+)")
|
||||
if groups[g:lower()] then
|
||||
if users == nil then
|
||||
users = { }
|
||||
end
|
||||
for user in string.gmatch(u, "([^,]+)") do
|
||||
users[user:lower()] = true
|
||||
end
|
||||
end
|
||||
end
|
||||
return users
|
||||
end
|
||||
|
||||
|
||||
-- Sets HTTP cookie headers based on post and sets up redirection.
|
||||
function authenticate_post()
|
||||
local hash = lookup_hash(post["username"])
|
||||
local redirect = validate_value("redirect", post["redirect"])
|
||||
|
||||
if redirect == nil then
|
||||
not_found()
|
||||
return 0
|
||||
end
|
||||
|
||||
redirect_to(redirect)
|
||||
|
||||
if hash == nil or hash ~= unistd.crypt(post["password"], hash) 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()
|
||||
accepted_users = lookup_users(cgit["repo"])
|
||||
if accepted_users == nil 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
|
||||
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("redirect", 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 secret = nil
|
||||
|
||||
-- Loads a secret from a file, creates a secret, or returns one from memory.
|
||||
function get_secret()
|
||||
if secret ~= nil then
|
||||
return secret
|
||||
end
|
||||
local secret_file = io.open(secret_filename, "r")
|
||||
if secret_file == nil then
|
||||
local old_umask = sysstat.umask(63)
|
||||
local temporary_filename = secret_filename .. ".tmp." .. crypto.hex(crypto.rand.bytes(16))
|
||||
local temporary_file = io.open(temporary_filename, "w")
|
||||
if temporary_file == nil then
|
||||
os.exit(177)
|
||||
end
|
||||
temporary_file:write(crypto.hex(crypto.rand.bytes(32)))
|
||||
temporary_file:close()
|
||||
unistd.link(temporary_filename, secret_filename) -- Intentionally fails in the case that another process is doing the same.
|
||||
unistd.unlink(temporary_filename)
|
||||
sysstat.umask(old_umask)
|
||||
secret_file = io.open(secret_filename, "r")
|
||||
end
|
||||
if secret_file == nil then
|
||||
os.exit(177)
|
||||
end
|
||||
secret = secret_file:read()
|
||||
secret_file:close()
|
||||
if secret:len() ~= 64 then
|
||||
os.exit(177)
|
||||
end
|
||||
return secret
|
||||
end
|
||||
|
||||
-- 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("sha256", field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt, get_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("sha256", authstr, get_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
|
||||
Ladataan…
Viittaa uudesa ongelmassa
Block a user