diff options
Diffstat (limited to 'util/sasl/scram.lua')
-rw-r--r-- | util/sasl/scram.lua | 91 |
1 files changed, 37 insertions, 54 deletions
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index f64feb8b..865f8cf7 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -14,16 +14,12 @@ local s_match = string.match; local type = type local base64 = require "util.encodings".base64; -local hmac_sha1 = require "util.hashes".hmac_sha1; -local sha1 = require "util.hashes".sha1; -local Hi = require "util.hashes".scram_Hi_sha1; +local hashes = require "util.hashes"; local generate_uuid = require "util.uuid".generate; local saslprep = require "util.encodings".stringprep.saslprep; local nodeprep = require "util.encodings".stringprep.nodeprep; local log = require "util.logger".init("sasl"); -local t_concat = table.concat; -local char = string.char; -local byte = string.byte; +local binaryXOR = require "util.strbitop".sxor; local _ENV = nil; -- luacheck: std none @@ -47,32 +43,6 @@ Supported Channel Binding Backends local default_i = 4096 -local xor_map = { - 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,1,0,3,2,5,4,7,6,9,8,11,10, - 13,12,15,14,2,3,0,1,6,7,4,5,10,11,8,9,14,15,12,13,3,2,1,0,7,6,5, - 4,11,10,9,8,15,14,13,12,4,5,6,7,0,1,2,3,12,13,14,15,8,9,10,11,5, - 4,7,6,1,0,3,2,13,12,15,14,9,8,11,10,6,7,4,5,2,3,0,1,14,15,12,13, - 10,11,8,9,7,6,5,4,3,2,1,0,15,14,13,12,11,10,9,8,8,9,10,11,12,13, - 14,15,0,1,2,3,4,5,6,7,9,8,11,10,13,12,15,14,1,0,3,2,5,4,7,6,10, - 11,8,9,14,15,12,13,2,3,0,1,6,7,4,5,11,10,9,8,15,14,13,12,3,2,1, - 0,7,6,5,4,12,13,14,15,8,9,10,11,4,5,6,7,0,1,2,3,13,12,15,14,9,8, - 11,10,5,4,7,6,1,0,3,2,14,15,12,13,10,11,8,9,6,7,4,5,2,3,0,1,15, - 14,13,12,11,10,9,8,7,6,5,4,3,2,1,0, -}; - -local result = {}; -local function binaryXOR( a, b ) - for i=1, #a do - local x, y = byte(a, i), byte(b, i); - local lowx, lowy = x % 16, y % 16; - local hix, hiy = (x - lowx) / 16, (y - lowy) / 16; - local lowr, hir = xor_map[lowx * 16 + lowy + 1], xor_map[hix * 16 + hiy + 1]; - local r = hir * 16 + lowr; - result[i] = char(r) - end - return t_concat(result); -end - local function validate_username(username, _nodeprep) -- check for forbidden char sequences for eq in username:gmatch("=(.?.?)") do @@ -99,24 +69,26 @@ local function hashprep(hashname) return hashname:lower():gsub("-", "_"); end -local function getAuthenticationDatabaseSHA1(password, salt, iteration_count) - if type(password) ~= "string" or type(salt) ~= "string" or type(iteration_count) ~= "number" then - return false, "inappropriate argument types" - end - if iteration_count < 4096 then - log("warn", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.") - end - password = saslprep(password); - if not password then - return false, "password fails SASLprep"; +local function get_scram_hasher(H, HMAC, Hi) + return function (password, salt, iteration_count) + if type(password) ~= "string" or type(salt) ~= "string" or type(iteration_count) ~= "number" then + return false, "inappropriate argument types" + end + if iteration_count < 4096 then + log("warn", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.") + end + password = saslprep(password); + if not password then + return false, "password fails SASLprep"; + end + local salted_password = Hi(password, salt, iteration_count); + local stored_key = H(HMAC(salted_password, "Client Key")) + local server_key = HMAC(salted_password, "Server Key"); + return true, stored_key, server_key end - local salted_password = Hi(password, salt, iteration_count); - local stored_key = sha1(hmac_sha1(salted_password, "Client Key")) - local server_key = hmac_sha1(salted_password, "Server Key"); - return true, stored_key, server_key end -local function scram_gen(hash_name, H_f, HMAC_f) +local function scram_gen(hash_name, H_f, HMAC_f, get_auth_db, expect_cb) local profile_name = "scram_" .. hashprep(hash_name); local function scram_hash(self, message) local support_channel_binding = false; @@ -129,6 +101,7 @@ local function scram_gen(hash_name, H_f, HMAC_f) local client_first_message = message; -- TODO: fail if authzid is provided, since we don't support them yet + -- luacheck: ignore 211/authzid local gs2_header, gs2_cbind_flag, gs2_cbind_name, authzid, client_first_message_bare, username, clientnonce = s_match(client_first_message, "^(([pny])=?([^,]*),([^,]*),)(m?=?[^,]*,?n=([^,]*),r=([^,]*),?.*)$"); @@ -144,6 +117,10 @@ local function scram_gen(hash_name, H_f, HMAC_f) if gs2_cbind_flag == "n" then -- "n" -> client doesn't support channel binding. + if expect_cb then + log("debug", "Client unexpectedly doesn't support channel binding"); + -- XXX Is it sensible to abort if the client starts -PLUS but doesn't use channel binding? + end support_channel_binding = false; end @@ -181,7 +158,7 @@ local function scram_gen(hash_name, H_f, HMAC_f) iteration_count = default_i; local succ; - succ, stored_key, server_key = getAuthenticationDatabaseSHA1(password, salt, iteration_count); + succ, stored_key, server_key = get_auth_db(password, salt, iteration_count); if not succ then log("error", "Generating authentication database failed. Reason: %s", stored_key); return "failure", "temporary-auth-failure"; @@ -194,7 +171,7 @@ local function scram_gen(hash_name, H_f, HMAC_f) end local nonce = clientnonce .. generate_uuid(); - local server_first_message = "r="..nonce..",s="..base64.encode(salt)..",i="..iteration_count; + local server_first_message = ("r=%s,s=%s,i=%d"):format(nonce, base64.encode(salt), iteration_count); self.state = { gs2_header = gs2_header; gs2_cbind_name = gs2_cbind_name; @@ -251,22 +228,28 @@ local function scram_gen(hash_name, H_f, HMAC_f) return scram_hash; end +local auth_db_getters = {} local function init(registerMechanism) - local function registerSCRAMMechanism(hash_name, hash, hmac_hash) + local function registerSCRAMMechanism(hash_name, hash, hmac_hash, pbkdf2) + local get_auth_db = get_scram_hasher(hash, hmac_hash, pbkdf2); + auth_db_getters[hash_name] = get_auth_db; registerMechanism("SCRAM-"..hash_name, {"plain", "scram_"..(hashprep(hash_name))}, - scram_gen(hash_name:lower(), hash, hmac_hash)); + scram_gen(hash_name:lower(), hash, hmac_hash, get_auth_db)); -- register channel binding equivalent registerMechanism("SCRAM-"..hash_name.."-PLUS", {"plain", "scram_"..(hashprep(hash_name))}, - scram_gen(hash_name:lower(), hash, hmac_hash), {"tls-unique"}); + scram_gen(hash_name:lower(), hash, hmac_hash, get_auth_db, true), {"tls-unique"}); end - registerSCRAMMechanism("SHA-1", sha1, hmac_sha1); + registerSCRAMMechanism("SHA-1", hashes.sha1, hashes.hmac_sha1, hashes.pbkdf2_hmac_sha1); + registerSCRAMMechanism("SHA-256", hashes.sha256, hashes.hmac_sha256, hashes.pbkdf2_hmac_sha256); end return { - getAuthenticationDatabaseSHA1 = getAuthenticationDatabaseSHA1; + get_hash = get_scram_hasher; + hashers = auth_db_getters; + getAuthenticationDatabaseSHA1 = get_scram_hasher(hashes.sha1, hashes.hmac_sha1, hashes.pbkdf2_hmac_sha1); -- COMPAT init = init; } |