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-rw-r--r--util/sasl/scram.lua93
1 files changed, 38 insertions, 55 deletions
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua
index f64feb8b..f11ae2e0 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";
@@ -194,11 +171,11 @@ 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;
- username = username;
+ username = self.username; -- Reference property instead of local, in case it was modified by the profile
nonce = nonce;
server_key = server_key;
@@ -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;
}