Diffstat (limited to 'filters/simple-authentication.lua')
| -rw-r--r-- | filters/simple-authentication.lua | 90 |
1 files changed, 28 insertions, 62 deletions
diff --git a/filters/simple-authentication.lua b/filters/simple-authentication.lua index 23d3457..de34d09 100644 --- a/filters/simple-authentication.lua +++ b/filters/simple-authentication.lua @@ -1,15 +1,10 @@ -- This script may be used with the auth-filter. Be sure to configure it as you wish. -- -- Requirements: --- luaossl --- <http://25thandclement.com/~william/projects/luaossl.html> --- luaposix --- <https://github.com/luaposix/luaposix> +-- luacrypto >= 0.3 +-- <http://mkottman.github.io/luacrypto/> -- -local sysstat = require("posix.sys.stat") -local unistd = require("posix.unistd") -local rand = require("openssl.rand") -local hmac = require("openssl.hmac") + -- -- @@ -23,16 +18,24 @@ local protected_repos = { qt = { jason = true, bob = true } } --- A list of users and hashes, generated with `mkpasswd -m sha-512 -R 300000`. +-- 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 = "$6$rounds=300000$YYJct3n/o.ruYK$HhpSeuCuW1fJkpvMZOZzVizeLsBKcGA/aF2UPuV5v60JyH2MVSG6P511UMTj2F3H75.IT2HIlnvXzNb60FcZH1", - laurent = "$6$rounds=300000$dP0KNHwYb3JKigT$pN/LG7rWxQ4HniFtx5wKyJXBJUKP7R01zTNZ0qSK/aivw8ywGAOdfYiIQFqFhZFtVGvr11/7an.nesvm8iJUi.", - bob = "$6$rounds=300000$jCLCCt6LUpTz$PI1vvd1yaVYcCzqH8QAJFcJ60b6W/6sjcOsU7mAkNo7IE8FRGW1vkjF8I/T5jt/auv5ODLb1L4S2s.CAyZyUC" + jason = "secretpassword", + laurent = "s3cr3t", + bob = "ilikelua" } --- Set this to a path this script can write to for storing a persistent --- cookie secret, which should be guarded. -local secret_filename = "/var/cache/cgit/auth-secret" +-- 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" + + -- -- @@ -42,7 +45,7 @@ local secret_filename = "/var/cache/cgit/auth-secret" -- Sets HTTP cookie headers based on post and sets up redirection. function authenticate_post() - local hash = users[post["username"]] + local password = users[post["username"]] local redirect = validate_value("redirect", post["redirect"]) if redirect == nil then @@ -52,7 +55,8 @@ function authenticate_post() redirect_to(redirect) - if hash == nil or hash ~= unistd.crypt(post["password"], hash) then + -- 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 @@ -180,13 +184,6 @@ function get_cookie(cookies, name) 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 -- -- @@ -194,38 +191,7 @@ end -- -- -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 +local crypto = require("crypto") -- Returns value of cookie if cookie is valid. Otherwise returns nil. function validate_value(expected_field, cookie) @@ -234,7 +200,7 @@ function validate_value(expected_field, cookie) local field = "" local expiration = 0 local salt = "" - local chmac = "" + local hmac = "" if cookie == nil or cookie:len() < 3 or cookie:sub(1, 1) == "|" then return nil @@ -253,19 +219,19 @@ function validate_value(expected_field, cookie) elseif i == 3 then salt = component elseif i == 4 then - chmac = component + hmac = component else break end i = i + 1 end - if chmac == nil or chmac:len() == 0 then + if hmac == nil or hmac: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 + if hmac ~= crypto.hmac.digest("sha1", field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt, secret) then return nil end @@ -286,11 +252,11 @@ function secure_value(field, value, expiration) end local authstr = "" - local salt = tohex(rand.bytes(16)) + local salt = crypto.hex(crypto.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)) + authstr = authstr .. "|" .. crypto.hmac.digest("sha1", authstr, secret) return authstr end |