From 9a1b93edc7b012cc75a0f4bf5a5fe64cd300f6d8 Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Tue, 17 Nov 2009 00:56:41 +0100 Subject: Initial commit of SCRAM SASL mechanism. --- util/sasl/scram.lua | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 util/sasl/scram.lua (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua new file mode 100644 index 00000000..b7507f3e --- /dev/null +++ b/util/sasl/scram.lua @@ -0,0 +1,90 @@ +-- sasl.lua v0.4 +-- Copyright (C) 2008-2009 Tobias Markmann +-- +-- All rights reserved. +-- +-- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: +-- +-- * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. +-- * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. +-- * Neither the name of Tobias Markmann nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. +-- +-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +local s_match = string.match; + +local base64 = require "util.encodings".base64; +local xor = require "bit".bxor +local hmac_sha1 = require "util.hmac".sha1; +local sha1 = require "util.hashes".sha1; + +module "plain" + +--========================= +--SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10 +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 function binaryXOR( a, b ) + if string.len(a) > string.len(b) then + b = string.rep("\0", a:len() - b:len())..b + elseif string.len(a) < string.len(b) then + a = string.rep("\0", b:len() - a:len())..a + end + local result = "" + for i=1, a:len() do + result = result..string.char(xor(a:byte(i), b:byte(i))) + end + return result +end + +-- hash algorithm independent Hi(PBKDF2) implementation +local function Hi(hmac, str, salt, i) + local Ust = hmac(str, salt.."\0\0\0\1"); + local res = Ust; + for n=1,i-1 do + Und = hmac(str, Ust) + res = binaryXOR(res, Und) + Ust = Und + end + return res +end + +local function validate_username(username) + -- check for forbidden char sequences + + -- replace =2D with , and =3D with = + + -- apply SASLprep + return username; +end + +local function scram_sha_1(self, message) + if not self.state then self["state"] = {} end + + if not self.state.name then + -- we are processing client_first_message + self.state["name"] = string.match(client_first_message, "n=(.+),r=") + self.state["clientnonce"] = string.match(client_first_message, "r=([^,]+)") + + self.state.name = validate_username(self.state.name); + if not self.state.name then + return "failure", "malformed-request"; + end + else + -- we are processing client_final_message + end +end + +function init(registerMechanism) + registerMechanism("SCRAM-SHA-1", {"plain"}, scram_sha_1); +end + +return _M; \ No newline at end of file -- cgit v1.2.3 From 1fa16fc88c2492df997fa5471eb282e977602c25 Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Tue, 17 Nov 2009 11:03:54 +0100 Subject: Completed SCRAM-SHA-1 implementation to a ready-to-test state. --- util/sasl/scram.lua | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index b7507f3e..9362cca7 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -17,6 +17,7 @@ local base64 = require "util.encodings".base64; local xor = require "bit".bxor local hmac_sha1 = require "util.hmac".sha1; local sha1 = require "util.hashes".sha1; +local generate_uuid = require "util.uuid".generate; module "plain" @@ -71,15 +72,52 @@ local function scram_sha_1(self, message) if not self.state.name then -- we are processing client_first_message - self.state["name"] = string.match(client_first_message, "n=(.+),r=") - self.state["clientnonce"] = string.match(client_first_message, "r=([^,]+)") + local client_first_message = message; + self.state["name"] = client_first_message:match("n=(.+),r=") + self.state["clientnonce"] = client_first_message:match("r=([^,]+)") self.state.name = validate_username(self.state.name); - if not self.state.name then + if not self.state.name or not self.state.clientnonce then return "failure", "malformed-request"; end + self.state["servernonce"] = generate_uuid(); + self.state["salt"] = generate_uuid(); + + local server_first_message = "r="..self.state.clientnonce..self.state.servernonce..",s="..base64.encode(self.state.salt)..",i="..default_i; + return "challenge", server_first_message else -- we are processing client_final_message + local client_final_message = message; + + self.state["proof"] = client_final_message:match("p=(.+)"); + self.state["nonce"] = client_final_message:match("r=(.+),p="); + self.state["channelbinding"] = client_final_message:match("c=(.+),r="); + if not self.state.proof or not self.state.nonce or not self.state.channelbinding then + return "failure", "malformed-request"; + end + + local password; + if self.profile.plain then + password, state = self.profile.plain(self.state.name, self.realm) + if state == nil then return "failure", "not-authorized" + elseif state == false then return "failure", "account-disabled" end + end + + local SaltedPassword = Hi(hmac_sha1, password, self.state.salt, default_i) + local ClientKey = hmac_sha1(SaltedPassword, "Client Key") + local ServerKey = hmac_sha1(SaltedPassword, "Server Key") + local StoredKey = sha1(ClientKey) + local AuthMessage = "n=" .. s_match(client_first_message,"n=(.+)") .. "," .. server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+") + local ClientSignature = hmac_sha1(StoredKey, AuthMessage) + local ClientProof = binaryXOR(ClientKey, ClientSignature) + local ServerSignature = hmac_sha1(ServerKey, AuthMessage) + + if base64.encode(ClientProof) == self.state.proof then + local server_final_message = "v="..base64.encode(ServerSignature); + return "success", server_final_message; + else + return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated."; + end end end -- cgit v1.2.3 From 12c7adc2e7a748941853a43102ec73e07d51850b Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Tue, 17 Nov 2009 11:31:59 +0100 Subject: Add check for forbidden char sequences in validate_username(). --- util/sasl/scram.lua | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index 9362cca7..c3bc9600 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -60,7 +60,8 @@ end local function validate_username(username) -- check for forbidden char sequences - + for eq in s:gmatch("=(.?.?)") do + if eq ~= "2D" and eq ~= "3D" then return false end end return true; -- replace =2D with , and =3D with = -- apply SASLprep -- cgit v1.2.3 From b0f89bf88505895e77bfda26c0e2720c14bf2918 Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Tue, 17 Nov 2009 22:39:18 +0100 Subject: Making interop with libpurple. (Thanks darkrain). --- util/sasl/scram.lua | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index c3bc9600..a347e2f3 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -12,7 +12,8 @@ -- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. local s_match = string.match; - +local type = type +local string = string local base64 = require "util.encodings".base64; local xor = require "bit".bxor local hmac_sha1 = require "util.hmac".sha1; @@ -34,7 +35,7 @@ local function bp( b ) end local function binaryXOR( a, b ) - if string.len(a) > string.len(b) then + if a:len() > b:len() then b = string.rep("\0", a:len() - b:len())..b elseif string.len(a) < string.len(b) then a = string.rep("\0", b:len() - a:len())..a @@ -60,8 +61,12 @@ end local function validate_username(username) -- check for forbidden char sequences - for eq in s:gmatch("=(.?.?)") do - if eq ~= "2D" and eq ~= "3D" then return false end end return true; + for eq in username:gmatch("=(.?.?)") do + if eq ~= "2D" and eq ~= "3D" then + return false + end + end + -- replace =2D with , and =3D with = -- apply SASLprep @@ -74,6 +79,7 @@ local function scram_sha_1(self, message) if not self.state.name then -- we are processing client_first_message local client_first_message = message; + self.state["client_first_message"] = client_first_message; self.state["name"] = client_first_message:match("n=(.+),r=") self.state["clientnonce"] = client_first_message:match("r=([^,]+)") @@ -85,8 +91,10 @@ local function scram_sha_1(self, message) self.state["salt"] = generate_uuid(); local server_first_message = "r="..self.state.clientnonce..self.state.servernonce..",s="..base64.encode(self.state.salt)..",i="..default_i; + self.state["server_first_message"] = server_first_message; return "challenge", server_first_message else + if type(message) ~= "string" then return "failure", "malformed-request" end -- we are processing client_final_message local client_final_message = message; @@ -108,13 +116,14 @@ local function scram_sha_1(self, message) local ClientKey = hmac_sha1(SaltedPassword, "Client Key") local ServerKey = hmac_sha1(SaltedPassword, "Server Key") local StoredKey = sha1(ClientKey) - local AuthMessage = "n=" .. s_match(client_first_message,"n=(.+)") .. "," .. server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+") + local AuthMessage = "n=" .. s_match(self.state.client_first_message,"n=(.+)") .. "," .. self.state.server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+") local ClientSignature = hmac_sha1(StoredKey, AuthMessage) local ClientProof = binaryXOR(ClientKey, ClientSignature) local ServerSignature = hmac_sha1(ServerKey, AuthMessage) if base64.encode(ClientProof) == self.state.proof then local server_final_message = "v="..base64.encode(ServerSignature); + self["username"] = self.state.name; return "success", server_final_message; else return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated."; -- cgit v1.2.3 From 7815630d28c0ffe23c63c54eeb4f401252b61d0f Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Wed, 18 Nov 2009 11:59:50 +0100 Subject: SASLprep usernames and passwords. --- util/sasl/scram.lua | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index a347e2f3..7d60ef86 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -19,6 +19,8 @@ local xor = require "bit".bxor local hmac_sha1 = require "util.hmac".sha1; local sha1 = require "util.hashes".sha1; local generate_uuid = require "util.uuid".generate; +local saslprep = require "util.encodings".stringprep.saslprep; +local log = require "util.logger".init("sasl"); module "plain" @@ -70,6 +72,7 @@ local function validate_username(username) -- replace =2D with , and =3D with = -- apply SASLprep + username = saslprep(username); return username; end @@ -83,10 +86,16 @@ local function scram_sha_1(self, message) self.state["name"] = client_first_message:match("n=(.+),r=") self.state["clientnonce"] = client_first_message:match("r=([^,]+)") - self.state.name = validate_username(self.state.name); if not self.state.name or not self.state.clientnonce then return "failure", "malformed-request"; end + + self.state.name = validate_username(self.state.name); + if not self.state.name then + log("debug", "Username violates either SASLprep or contains forbidden character sequences.") + return "failure", "malformed-request"; + end + self.state["servernonce"] = generate_uuid(); self.state["salt"] = generate_uuid(); @@ -110,6 +119,11 @@ local function scram_sha_1(self, message) password, state = self.profile.plain(self.state.name, 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" + end end local SaltedPassword = Hi(hmac_sha1, password, self.state.salt, default_i) -- cgit v1.2.3 From 6117baa28d8658b16a4de88f4183bef42bed8e0a Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Thu, 19 Nov 2009 00:04:14 +0100 Subject: Handle , and = in usernames for SCRAM. --- util/sasl/scram.lua | 2 ++ 1 file changed, 2 insertions(+) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index 7d60ef86..a7b21d0d 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -70,6 +70,8 @@ local function validate_username(username) end -- replace =2D with , and =3D with = + username:gsub("=2D", ","); + username:gsub("=3D", "="); -- apply SASLprep username = saslprep(username); -- cgit v1.2.3 From d5511aa898fea7f142f3b61799ea0724b4b8877f Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Thu, 19 Nov 2009 15:29:09 +0100 Subject: Typo. --- util/sasl/scram.lua | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index a7b21d0d..f7b8300a 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -22,7 +22,7 @@ local generate_uuid = require "util.uuid".generate; local saslprep = require "util.encodings".stringprep.saslprep; local log = require "util.logger".init("sasl"); -module "plain" +module "scram" --========================= --SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10 -- cgit v1.2.3 From b32b0e118daa6a32b464bf21e7c091041eec0dbb Mon Sep 17 00:00:00 2001 From: Tobias Markmann Date: Thu, 19 Nov 2009 17:17:52 +0100 Subject: Adding some human readable error messages. --- util/sasl/scram.lua | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'util/sasl/scram.lua') diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index f7b8300a..4413e2a6 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -95,7 +95,7 @@ local function scram_sha_1(self, message) self.state.name = validate_username(self.state.name); if not self.state.name then log("debug", "Username violates either SASLprep or contains forbidden character sequences.") - return "failure", "malformed-request"; + return "failure", "malformed-request", "Invalid username."; end self.state["servernonce"] = generate_uuid(); @@ -113,7 +113,7 @@ local function scram_sha_1(self, message) self.state["nonce"] = client_final_message:match("r=(.+),p="); self.state["channelbinding"] = client_final_message:match("c=(.+),r="); if not self.state.proof or not self.state.nonce or not self.state.channelbinding then - return "failure", "malformed-request"; + return "failure", "malformed-request", "Missing an attribute(p, r or c) in SASL message."; end local password; @@ -124,7 +124,7 @@ local function scram_sha_1(self, message) password = saslprep(password); if not password then log("debug", "Password violates SASLprep."); - return "failure", "not-authorized" + return "failure", "not-authorized", "Invalid password." end end -- cgit v1.2.3