Merge 0.9->0.10

2 files changed, 114 insertions, 56 deletions

diff --git a/util/sasl/external.lua b/util/sasl/external.lua
new file mode 100644
index 00000000..4c5c4343
--- /dev/null
+++ b/util/sasl/external.lua
@@ -0,0 +1,25 @@
+local saslprep = require "util.encodings".stringprep.saslprep;
+
+module "sasl.external"
+
+local function external(self, message)
+	message = saslprep(message);
+	local state
+	self.username, state = self.profile.external(message);
+
+	if state == false then
+		return "failure", "account-disabled";
+	elseif state == nil  then
+		return "failure", "not-authorized";
+	elseif state == "expired" then
+		return "false", "credentials-expired";
+	end
+
+	return "success";
+end
+
+function init(registerMechanism)
+	registerMechanism("EXTERNAL", {"external"}, external);
+end
+
+return _M;
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua
index cf2f0ede..0d2852bf 100644
--- a/util/sasl/scram.lua
+++ b/util/sasl/scram.lua
@@ -13,7 +13,6 @@
 
 local s_match = string.match;
 local type = type
-local string = string
 local base64 = require "util.encodings".base64;
 local hmac_sha1 = require "util.hashes".hmac_sha1;
 local sha1 = require "util.hashes".sha1;
@@ -39,18 +38,14 @@ scram_{MECH}:
 	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 = {};
@@ -73,11 +68,11 @@ local function validate_username(username, _nodeprep)
 			return false
 		end
 	end
-	
+
 	-- replace =2C with , and =3D with =
 	username = username:gsub("=2C", ",");
 	username = username:gsub("=3D", "=");
-	
+
 	-- apply SASLprep
 	username = saslprep(username);
 
@@ -106,96 +101,131 @@ function getAuthenticationDatabaseSHA1(password, salt, iteration_count)
 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;
-			
+
 			-- 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["authzid"], self.state["name"], self.state["clientnonce"]
-				= client_first_message:match("^(%a),(.*),n=(.*),r=([^,]*).*");
+			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=([^,]*),?.*)$");
 
-			-- we don't do any channel binding yet
-			if self.state.gs2_cbind_flag ~= "n" and self.state.gs2_cbind_flag ~= "y" then
+			if not gs2_cbind_flag then
 				return "failure", "malformed-request";
 			end
 
-			if not self.state.name or not self.state.clientnonce then
-				return "failure", "malformed-request", "Channel binding isn't support at this time.";
+			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
-		
-			self.state.name = validate_username(self.state.name, self.profile.nodeprep);
-			if not self.state.name then
+
+			if support_channel_binding and gs2_cbind_flag == "p" then
+				-- check whether we support the proposed channel binding type
+				if not self.profile.cb[gs2_cbind_name] then
+					return "failure", "malformed-request", "Proposed channel binding type isn't supported.";
+				end
+			else
+				-- no channel binding,
+				gs2_cbind_name = nil;
+			end
+
+			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;
-			
-			self.state["channelbinding"], self.state["nonce"], self.state["proof"] = client_final_message:match("^c=(.*),r=(.*),.*p=(.*)");
-	
-			if not self.state.proof or not self.state.nonce or not self.state.channelbinding then
+
+			local client_final_message_without_proof, channelbinding, nonce, proof
+				= s_match(client_final_message, "(c=([^,]*),r=([^,]*),?.-),p=(.*)$");
+
+			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.";
@@ -208,6 +238,9 @@ end
 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), {"tls-unique"});
 	end
 
 	registerSCRAMMechanism("SHA-1", sha1, hmac_sha1);