diff options
Diffstat (limited to 'util/sasl/scram.lua')
| -rw-r--r-- | util/sasl/scram.lua | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index f64feb8b..009a01ce 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -14,9 +14,7 @@ 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; @@ -99,24 +97,26 @@ 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 +129,7 @@ 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 +145,10 @@ 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 +186,7 @@ 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 +199,7 @@ 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 +256,28 @@ 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; } |