diff options
Diffstat (limited to 'util/sasl/scram.lua')
| -rw-r--r-- | util/sasl/scram.lua | 57 |
1 files changed, 28 insertions, 29 deletions
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua index 1340423c..aad33ebc 100644 --- a/util/sasl/scram.lua +++ b/util/sasl/scram.lua @@ -24,10 +24,10 @@ local t_concat = table.concat; local char = string.char; local byte = string.byte; -module "scram" +module "sasl.scram" --========================= ---SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10 +--SASL SCRAM-SHA-1 according to RFC 5802 --[[ Supported Authentication Backends @@ -35,7 +35,7 @@ Supported Authentication Backends scram_{MECH}: -- MECH being a standard hash name (like those at IANA's hash registry) with '-' replaced with '_' function(username, realm) - return salted_password, iteration_count, salt, state; + return stored_key, server_key, iteration_count, salt, state; end ]] @@ -65,9 +65,9 @@ local function binaryXOR( a, b ) end -- hash algorithm independent Hi(PBKDF2) implementation -local function Hi(hmac, str, salt, i) +function Hi(hmac, str, salt, i) local Ust = hmac(str, salt.."\0\0\0\1"); - local res = Ust; + local res = Ust; for n=1,i-1 do local Und = hmac(str, Ust) res = binaryXOR(res, Und) @@ -79,13 +79,13 @@ end local function validate_username(username) -- check for forbidden char sequences for eq in username:gmatch("=(.?.?)") do - if eq ~= "2D" and eq ~= "3D" then - return false - end + 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 @@ -93,22 +93,21 @@ local function validate_username(username) return username; end -local function hashprep( hashname ) - local hash = hashname:lower() - hash = hash:gsub("-", "_") - return hash +local function hashprep(hashname) + return hashname:lower():gsub("-", "_"); end -function saltedPasswordSHA1(password, salt, iteration_count) - local salted_password +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 - - return true, Hi(hmac_sha1, password, salt, iteration_count); + local salted_password = Hi(hmac_sha1, 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) @@ -144,7 +143,7 @@ local function scram_gen(hash_name, H_f, HMAC_f) -- retreive credentials if self.profile.plain then - local password, state = self.profile.plain(self.state.name, self.realm) + local password, state = self.profile.plain(self, self.state.name, self.realm) if state == nil then return "failure", "not-authorized" elseif state == false then return "failure", "account-disabled" end @@ -158,17 +157,18 @@ local function scram_gen(hash_name, H_f, HMAC_f) self.state.iteration_count = default_i; local succ = false; - succ, self.state.salted_password = saltedPasswordSHA1(password, self.state.salt, default_i, self.state.iteration_count); + succ, self.state.stored_key, self.state.server_key = getAuthenticationDatabaseSHA1(password, self.state.salt, default_i, self.state.iteration_count); if not succ then - log("error", "Generating salted password failed. Reason: %s", self.state.salted_password); + log("error", "Generating authentication database failed. Reason: %s", self.state.stored_key); return "failure", "temporary-auth-failure"; end elseif self.profile["scram_"..hashprep(hash_name)] then - local salted_password, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self.state.name, self.realm); + local stored_key, server_key, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self, self.state.name, self.realm); if state == nil then return "failure", "not-authorized" elseif state == false then return "failure", "account-disabled" end - self.state.salted_password = salted_password; + self.state.stored_key = stored_key; + self.state.server_key = server_key; self.state.iteration_count = iteration_count; self.state.salt = salt end @@ -190,16 +190,15 @@ local function scram_gen(hash_name, H_f, HMAC_f) return "failure", "malformed-request", "Wrong nonce in client-final-message."; end - local SaltedPassword = self.state.salted_password; - local ClientKey = HMAC_f(SaltedPassword, "Client Key") - local ServerKey = HMAC_f(SaltedPassword, "Server Key") - local StoredKey = H_f(ClientKey) + 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 ClientSignature = HMAC_f(StoredKey, AuthMessage) - local ClientProof = binaryXOR(ClientKey, ClientSignature) + local ClientKey = binaryXOR(ClientSignature, base64.decode(self.state.proof)) local ServerSignature = HMAC_f(ServerKey, AuthMessage) - if base64.encode(ClientProof) == self.state.proof then + if StoredKey == H_f(ClientKey) then local server_final_message = "v="..base64.encode(ServerSignature); self["username"] = self.state.name; return "success", server_final_message; |