local s_match = string.match;
local type = type
-local string = string
-local tostring = tostring;
local base64 = require "util.encodings".base64;
-local hmac_sha1 = require "util.hmac".sha1;
+local hmac_sha1 = require "util.hashes".hmac_sha1;
local sha1 = require "util.hashes".sha1;
+local Hi = require "util.hashes".scram_Hi_sha1;
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;
-module "scram"
+local _ENV = nil;
--=========================
--SASL SCRAM-SHA-1 according to RFC 5802
function(username, realm)
return stored_key, server_key, iteration_count, salt, state;
end
+
+Supported Channel Binding Backends
+
+'tls-unique' according to RFC 5929
]]
local default_i = 4096
-local function bp( b )
- local result = ""
- for i=1, b:len() do
- result = result.."\\"..b:byte(i)
- end
- return result
-end
-
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 = {};
return t_concat(result);
end
--- hash algorithm independent Hi(PBKDF2) implementation
-function Hi(hmac, str, salt, i)
- local Ust = hmac(str, salt.."\0\0\0\1");
- local res = Ust;
- for n=1,i-1 do
- local Und = hmac(str, Ust)
- res = binaryXOR(res, Und)
- Ust = Und
- end
- return res
-end
-
-local function validate_username(username)
+local function validate_username(username, _nodeprep)
-- check for forbidden char sequences
for eq in username:gmatch("=(.?.?)") do
- if eq ~= "2D" and eq ~= "3D" then
+ if eq ~= "2C" and eq ~= "3D" then
return false
end
end
-
- -- replace =2D with , and =3D with =
- username = username:gsub("=2D", ",");
+
+ -- replace =2C with , and =3D with =
+ username = username:gsub("=2C", ",");
username = username:gsub("=3D", "=");
-
+
-- apply SASLprep
username = saslprep(username);
- return username;
+
+ if username and _nodeprep ~= false then
+ username = (_nodeprep or nodeprep)(username);
+ end
+
+ return username and #username>0 and username;
end
local function hashprep(hashname)
return hashname:lower():gsub("-", "_");
end
-function getAuthenticationDatabaseSHA1(password, salt, iteration_count)
+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
- local salted_password = Hi(hmac_sha1, password, salt, iteration_count);
+ 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 profile_name = "scram_" .. hashprep(hash_name);
local function scram_hash(self, message)
- if not self.state then self["state"] = {} end
local support_channel_binding = false;
if self.profile.cb then support_channel_binding = true; end
-
+
if type(message) ~= "string" or #message == 0 then return "failure", "malformed-request" end
- if not self.state.name then
+ local state = self.state;
+ if not state then
-- we are processing client_first_message
local client_first_message = message;
- log("debug", client_first_message);
+
-- TODO: fail if authzid is provided, since we don't support them yet
- self.state["client_first_message"] = client_first_message;
- self.state["gs2_cbind_flag"], self.state["gs2_cbind_name"], self.state["authzid"], self.state["name"], self.state["clientnonce"]
- = client_first_message:match("^(%a)=?([%a%-]*),(.*),n=(.*),r=([^,]*).*");
-
- -- we don't do any channel binding yet
- log("debug", "Decoded: cbind_flag: %s, cbind_name: %s, authzid: %s, name: %s, clientnonce: %s", tostring(self.state.gs2_cbind_flag),
- tostring(self.state.gs2_cbind_name),
- tostring(self.state.authzid),
- tostring(self.state.name),
- tostring(self.state.clientnonce));
- if support_channel_binding then
- if string.sub(self.state.gs2_cbind_flag, 0, 1) == "y" then
+ 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=([^,]*),?.*)$");
+
+ if not gs2_cbind_flag then
+ return "failure", "malformed-request";
+ end
+
+ if support_channel_binding and gs2_cbind_flag == "y" then
+ -- "y" -> client does support channel binding
+ -- but thinks the server does not.
return "failure", "malformed-request";
end
-
+
+ if gs2_cbind_flag == "n" then
+ -- "n" -> client doesn't support channel binding.
+ support_channel_binding = false;
+ end
+
+ if support_channel_binding and gs2_cbind_flag == "p" then
-- check whether we support the proposed channel binding type
- if not self.profile.cb[self.state.gs2_cbind_name] then
+ if not self.profile.cb[gs2_cbind_name] then
return "failure", "malformed-request", "Proposed channel binding type isn't supported.";
end
else
- if self.state.gs2_cbind_flag ~= "n" and self.state.gs2_cbind_flag ~= "y" then
- return "failure", "malformed-request";
- end
+ -- no channel binding,
+ gs2_cbind_name = nil;
end
- if not self.state.name or not self.state.clientnonce then
- return "failure", "malformed-request", "Channel binding isn't support at this time.";
- end
-
- self.state.name = validate_username(self.state.name);
- if not self.state.name then
+ username = validate_username(username, self.profile.nodeprep);
+ if not username then
log("debug", "Username violates either SASLprep or contains forbidden character sequences.")
return "failure", "malformed-request", "Invalid username.";
end
-
- self.state["servernonce"] = generate_uuid();
-
+
-- retreive credentials
+ local stored_key, server_key, salt, iteration_count;
if self.profile.plain then
- local password, state = self.profile.plain(self, self.state.name, self.realm)
+ local password, state = self.profile.plain(self, username, self.realm)
if state == nil then return "failure", "not-authorized"
elseif state == false then return "failure", "account-disabled" end
-
+
password = saslprep(password);
if not password then
log("debug", "Password violates SASLprep.");
return "failure", "not-authorized", "Invalid password."
end
- self.state.salt = generate_uuid();
- self.state.iteration_count = default_i;
+ salt = generate_uuid();
+ iteration_count = default_i;
local succ = false;
- succ, self.state.stored_key, self.state.server_key = getAuthenticationDatabaseSHA1(password, self.state.salt, default_i, self.state.iteration_count);
+ succ, stored_key, server_key = getAuthenticationDatabaseSHA1(password, salt, iteration_count);
if not succ then
- log("error", "Generating authentication database failed. Reason: %s", self.state.stored_key);
+ log("error", "Generating authentication database failed. Reason: %s", stored_key);
return "failure", "temporary-auth-failure";
end
- elseif self.profile["scram_"..hashprep(hash_name)] then
- local stored_key, server_key, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self, self.state.name, self.realm);
+ elseif self.profile[profile_name] then
+ local state;
+ stored_key, server_key, iteration_count, salt, state = self.profile[profile_name](self, username, self.realm);
if state == nil then return "failure", "not-authorized"
elseif state == false then return "failure", "account-disabled" end
-
- self.state.stored_key = stored_key;
- self.state.server_key = server_key;
- self.state.iteration_count = iteration_count;
- self.state.salt = salt
end
-
- local server_first_message = "r="..self.state.clientnonce..self.state.servernonce..",s="..base64.encode(self.state.salt)..",i="..self.state.iteration_count;
- self.state["server_first_message"] = server_first_message;
+
+ local nonce = clientnonce .. generate_uuid();
+ local server_first_message = "r="..nonce..",s="..base64.encode(salt)..",i="..iteration_count;
+ self.state = {
+ gs2_header = gs2_header;
+ gs2_cbind_name = gs2_cbind_name;
+ username = username;
+ nonce = nonce;
+
+ server_key = server_key;
+ stored_key = stored_key;
+ client_first_message_bare = client_first_message_bare;
+ server_first_message = server_first_message;
+ }
return "challenge", server_first_message
else
-- we are processing client_final_message
local client_final_message = message;
- log("debug", "client_final_message: %s", client_final_message);
- self.state["channelbinding"], self.state["nonce"], self.state["proof"] = client_final_message:match("^c=(.*),r=(.*),.*p=(.*)");
- if self.state.gs2_cbind_name then
- local client_gs2_header = base64.decode(self.state.channelbinding)
- local our_client_gs2_header = "p="..self.state.gs2_cbind_name..","..self.state["authzid"]..","..self.profile.cb[self.state.gs2_cbind_name](self);
+ local client_final_message_without_proof, channelbinding, nonce, proof
+ = s_match(client_final_message, "(c=([^,]*),r=([^,]*),?.-),p=(.*)$");
- if client_gs2_header ~= our_client_gs2_header then
- return "failure", "malformed-request", "Invalid channel binding value.";
- end
- else
- if not self.state.proof or not self.state.nonce or not self.state.channelbinding then
- return "failure", "malformed-request", "Missing an attribute(p, r or c) in SASL message.";
- end
+ if not proof or not nonce or not channelbinding then
+ return "failure", "malformed-request", "Missing an attribute(p, r or c) in SASL message.";
end
- if self.state.nonce ~= self.state.clientnonce..self.state.servernonce then
+ local client_gs2_header = base64.decode(channelbinding)
+ local our_client_gs2_header = state["gs2_header"]
+ if state.gs2_cbind_name then
+ -- we support channelbinding, so check if the value is valid
+ our_client_gs2_header = our_client_gs2_header .. self.profile.cb[state.gs2_cbind_name](self);
+ end
+ if client_gs2_header ~= our_client_gs2_header then
+ return "failure", "malformed-request", "Invalid channel binding value.";
+ end
+
+ if nonce ~= state.nonce then
return "failure", "malformed-request", "Wrong nonce in client-final-message.";
end
-
- local ServerKey = self.state.server_key;
- local StoredKey = self.state.stored_key;
-
- local AuthMessage = "n=" .. s_match(self.state.client_first_message,"n=(.+)") .. "," .. self.state.server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+")
+
+ local ServerKey = state.server_key;
+ local StoredKey = state.stored_key;
+
+ local AuthMessage = state.client_first_message_bare .. "," .. state.server_first_message .. "," .. client_final_message_without_proof
local ClientSignature = HMAC_f(StoredKey, AuthMessage)
- local ClientKey = binaryXOR(ClientSignature, base64.decode(self.state.proof))
+ local ClientKey = binaryXOR(ClientSignature, base64.decode(proof))
local ServerSignature = HMAC_f(ServerKey, AuthMessage)
if StoredKey == H_f(ClientKey) then
local server_final_message = "v="..base64.encode(ServerSignature);
- self["username"] = self.state.name;
+ self["username"] = state.username;
return "success", server_final_message;
else
return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated.";
return scram_hash;
end
-function init(registerMechanism)
+local function init(registerMechanism)
local function registerSCRAMMechanism(hash_name, hash, hmac_hash)
registerMechanism("SCRAM-"..hash_name, {"plain", "scram_"..(hashprep(hash_name))}, scram_gen(hash_name:lower(), hash, hmac_hash));
-
+
-- register channel binding equivalent
- registerMechanism("SCRAM-"..hash_name.."-PLUS", {"plain", "scram_"..(hashprep(hash_name))}, scram_gen(hash_name:lower(), hash, hmac_hash));
+ registerMechanism("SCRAM-"..hash_name.."-PLUS", {"plain", "scram_"..(hashprep(hash_name))}, scram_gen(hash_name:lower(), hash, hmac_hash), {"tls-unique"});
end
registerSCRAMMechanism("SHA-1", sha1, hmac_sha1);
end
-return _M;
+return {
+ getAuthenticationDatabaseSHA1 = getAuthenticationDatabaseSHA1;
+ init = init;
+}
projects / prosody.git / blobdiff