diff options
Diffstat (limited to 'www/git.causal.agency/cgit/filters/file-authentication.lua')
| -rw-r--r-- | www/git.causal.agency/cgit/filters/file-authentication.lua | 359 |
1 files changed, 0 insertions, 359 deletions
diff --git a/www/git.causal.agency/cgit/filters/file-authentication.lua b/www/git.causal.agency/cgit/filters/file-authentication.lua deleted file mode 100644 index 02488046..00000000 --- a/www/git.causal.agency/cgit/filters/file-authentication.lua +++ /dev/null @@ -1,359 +0,0 @@ --- This script may be used with the auth-filter. --- --- Requirements: --- luaossl --- <http://25thandclement.com/~william/projects/luaossl.html> --- luaposix --- <https://github.com/luaposix/luaposix> --- -local sysstat = require("posix.sys.stat") -local unistd = require("posix.unistd") -local rand = require("openssl.rand") -local hmac = require("openssl.hmac") - --- 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 - -function tohex(b) - local x = "" - for i = 1, #b do - x = x .. string.format("%.2x", string.byte(b, i)) - end - return x -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." .. tohex(rand.bytes(16)) - local temporary_file = io.open(temporary_filename, "w") - if temporary_file == nil then - os.exit(177) - end - temporary_file:write(tohex(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 chmac = "" - - 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 - chmac = component - else - break - end - i = i + 1 - end - - if chmac == nil or chmac:len() == 0 then - return nil - end - - -- Lua hashes strings, so these comparisons are time invariant. - if chmac ~= tohex(hmac.new(get_secret(), "sha256"):final(field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt)) 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 = tohex(rand.bytes(16)) - value = url_encode(value) - field = url_encode(field) - authstr = field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt - authstr = authstr .. "|" .. tohex(hmac.new(get_secret(), "sha256"):final(authstr)) - 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 |