diff options
Diffstat (limited to 'filters/simple-authentication.lua')
-rw-r--r-- | filters/simple-authentication.lua | 69 |
1 files changed, 48 insertions, 21 deletions
diff --git a/filters/simple-authentication.lua b/filters/simple-authentication.lua index de34d09..77d1fd0 100644 --- a/filters/simple-authentication.lua +++ b/filters/simple-authentication.lua @@ -3,7 +3,12 @@ -- 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") -- @@ -18,24 +23,16 @@ local protected_repos = { qt = { jason = true, bob = true } } --- 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. +-- A list of users and hashes, generated with `mkpasswd -m sha-512 -R 300000`. local users = { - jason = "secretpassword", - laurent = "s3cr3t", - bob = "ilikelua" + 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" } --- 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" - - +-- 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" -- -- @@ -45,7 +42,7 @@ local secret = "BE SURE TO CUSTOMIZE THIS STRING TO SOMETHING BIG AND RANDOM" -- Sets HTTP cookie headers based on post and sets up redirection. function authenticate_post() - local password = users[post["username"]] + local hash = users[post["username"]] local redirect = validate_value("redirect", post["redirect"]) if redirect == nil then @@ -55,8 +52,7 @@ function authenticate_post() redirect_to(redirect) - -- Lua hashes strings, so these comparisons are time invariant. - if password == nil or password ~= post["password"] then + if hash == nil or hash ~= unistd.crypt(post["password"], hash) then set_cookie("cgitauth", "") else -- One week expiration time @@ -191,7 +187,38 @@ end -- -- -local crypto = require("crypto") +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) @@ -231,7 +258,7 @@ function validate_value(expected_field, cookie) end -- Lua hashes strings, so these comparisons are time invariant. - if hmac ~= crypto.hmac.digest("sha1", field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt, secret) then + if hmac ~= crypto.hmac.digest("sha256", field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt, get_secret()) then return nil end @@ -256,7 +283,7 @@ function secure_value(field, value, expiration) value = url_encode(value) field = url_encode(field) authstr = field .. "|" .. value .. "|" .. tostring(expiration) .. "|" .. salt - authstr = authstr .. "|" .. crypto.hmac.digest("sha1", authstr, secret) + authstr = authstr .. "|" .. crypto.hmac.digest("sha256", authstr, get_secret()) return authstr end |