commit
7fd094820d
@ -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 |
||||
Loading…
Reference in new issue