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Diffstat (limited to '')
-rw-r--r-- | nselib/membase.lua | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/nselib/membase.lua b/nselib/membase.lua new file mode 100644 index 0000000..9b721a6 --- /dev/null +++ b/nselib/membase.lua @@ -0,0 +1,337 @@ +--- +-- A smallish implementation of the Couchbase Membase TAP protocol +-- Based on the scarce documentation from the Couchbase Wiki: +-- * http://www.couchbase.org/wiki/display/membase/SASL+Authentication+Example +-- +-- @args membase.authmech SASL authentication mechanism to use. Default and +-- currently supported: PLAIN +-- +-- @author Patrik Karlsson <patrik@cqure.net> +-- + + +local match = require "match" +local nmap = require "nmap" +local sasl = require "sasl" +local stdnse = require "stdnse" +local string = require "string" +local table = require "table" +_ENV = stdnse.module("membase", stdnse.seeall) + +-- A minimalistic implementation of the Couchbase Membase TAP protocol +TAP = { + + -- Operations + Op = { + LIST_SASL_MECHS = 0x20, + AUTHENTICATE = 0x21, + }, + + -- Requests + Request = { + + -- Header breakdown + -- Field (offset) (value) + -- Magic (0): 0x80 (PROTOCOL_BINARY_REQ) + -- Opcode (1): 0x00 + -- Key length (2-3): 0x0000 (0) + -- Extra length (4): 0x00 + -- Data type (5): 0x00 + -- vbucket (6-7): 0x0000 (0) + -- Total body (8-11): 0x00000000 (0) + -- Opaque (12-15): 0x00000000 (0) + -- CAS (16-23): 0x0000000000000000 (0) + Header = { + + -- Creates a new instance of Header + -- @param opcode number containing the operation + -- @return o new instance of Header + new = function(self, opcode) + local o = { + magic = 0x80, + opcode = tonumber(opcode), + keylen = 0x0000, + extlen = 0x00, + data_type = 0x00, + vbucket = 0x0000, + total_body = 0x00000000, + opaque = 0x00000000, + CAS = 0x0000000000000000, + } + setmetatable(o, self) + self.__index = self + return o + end, + + -- Converts the header to string + -- @return string containing the Header as string + __tostring = function(self) + return string.pack(">BB I2 BB I2 I4 I4 I8", self.magic, self.opcode, self.keylen, + self.extlen, self.data_type, self.vbucket, self.total_body, + self.opaque, self.CAS) + end, + }, + + -- List SASL authentication mechanism + SASLList = { + + -- Creates a new instance of the request + -- @return o instance of request + new = function(self) + local o = { + -- 0x20 SASL List Mechs + header = TAP.Request.Header:new(TAP.Op.LIST_SASL_MECHS) + } + setmetatable(o, self) + self.__index = self + return o + end, + + -- Converts the request to string + -- @return string containing the request as string + __tostring = function(self) + return tostring(self.header) + end, + }, + + -- Authenticates using SASL + Authenticate = { + + -- Creates a new instance of the request + -- @param username string containing the username + -- @param password string containing the password + -- @param mech string containing the SASL mechanism, currently supported: + -- PLAIN - plain-text authentication + -- @return o instance of request + new = function(self, username, password, mech) + local o = { + -- 0x20 SASL List Mechs + header = TAP.Request.Header:new(TAP.Op.AUTHENTICATE), + username = username, + password = password, + mech = mech, + } + setmetatable(o, self) + self.__index = self + return o + end, + + -- Converts the request to string + -- @return string containing the request as string + __tostring = function(self) + if ( self.mech == "PLAIN" ) then + local mech_params = { self.username, self.password } + local auth_data = sasl.Helper:new(self.mech):encode(table.unpack(mech_params)) + + self.header.keylen = #self.mech + self.header.total_body = #auth_data + #self.mech + return tostring(self.header) .. self.mech .. auth_data + end + end, + + } + + }, + + -- Responses + Response = { + + -- The response header + -- Header breakdown + -- Field (offset) (value) + -- Magic (0): 0x81 (PROTOCOL_BINARY_RES) + -- Opcode (1): 0x00 + -- Key length (2-3): 0x0000 (0) + -- Extra length (4): 0x00 + -- Data type (5): 0x00 + -- Status (6-7): 0x0000 (SUCCESS) + -- Total body (8-11): 0x00000005 (5) + -- Opaque (12-15): 0x00000000 (0) + -- CAS (16-23): 0x0000000000000000 (0) + Header = { + + -- Creates a new instance of Header + -- @param data string containing the raw data + -- @return o new instance of Header + new = function(self, data) + local o = { + data = data + } + setmetatable(o, self) + self.__index = self + if ( o:parse() ) then + return o + end + end, + + -- Parse the raw header and populates the class members + -- @return status true on success, false on failure + parse = function(self) + if ( 24 > #self.data ) then + stdnse.debug1("membase: Header packet too short (%d bytes)", #self.data) + return false, "Packet to short" + end + local pos + self.magic, self.opcode, self.keylen, self.extlen, + self.data_type, self.status, self.total_body, self.opaque, + self.BAI2 , pos = string.unpack(">BB I2 BB I2 I4 I4 I8", self.data) + return true + end + + }, + + -- Decoders + Decoder = { + + -- TAP.Op.LIST_SASL_MECHS + [0x20] = { + -- Creates a new instance of the decoder + -- @param data string containing the raw response + -- @return o instance if successfully parsed, nil on failure + -- the member variable <code>mechs</code> contains the + -- supported authentication mechanisms. + new = function(self, data) + local o = { data = data } + setmetatable(o, self) + self.__index = self + if ( o:parse() ) then + return o + end + end, + + -- Parses the raw response + -- @return true on success + parse = function(self) + self.mechs = self.data + return true + end + }, + + -- Login response + [0x21] = { + -- Creates a new instance of the decoder + -- @param data string containing the raw response + -- @return o instance if successfully parsed, nil on failure + -- the member variable <code>status</code> contains the + -- servers authentication response. + new = function(self, data) + local o = { data = data } + setmetatable(o, self) + self.__index = self + if ( o:parse() ) then + return o + end + end, + + -- Parses the raw response + -- @return true on success + parse = function(self) + self.status = self.data + return true + end + } + + } + + }, + +} + +-- The Helper class is the main script interface +Helper = { + + -- Creates a new instance of the helper + -- @param host table as received by the action method + -- @param port table as received by the action method + -- @param options table including options to the helper, currently: + -- <code>timeout</code> - socket timeout in milliseconds + new = function(self, host, port, options) + local o = { + host = host, + port = port, + mech = stdnse.get_script_args("membase.authmech"), + options = options or {} + } + setmetatable(o, self) + self.__index = self + return o + end, + + -- Connects the socket to the server + -- @return true on success, false on failure + connect = function(self, socket) + self.socket = socket or nmap.new_socket() + self.socket:set_timeout(self.options.timeout or 10000) + return self.socket:connect(self.host, self.port) + end, + + -- Closes the socket + close = function(self) + return self.socket:close() + end, + + -- Sends a request to the server, receives and parses the response + -- @param req a Request instance + -- @return status true on success, false on failure + -- @return response instance of Response + exch = function(self, req) + local status, err = self.socket:send(tostring(req)) + if ( not(status) ) then + return false, "Failed to send data" + end + + local data + status, data = self.socket:receive_buf(match.numbytes(24), true) + if ( not(status) ) then + return false, "Failed to receive data" + end + + local header = TAP.Response.Header:new(data) + + if ( header.opcode ~= req.header.opcode ) then + stdnse.debug1("WARNING: Received invalid op code, request contained (%d), response contained (%d)", req.header.opcode, header.opcode) + end + + if ( not(TAP.Response.Decoder[tonumber(header.opcode)]) ) then + return false, ("No response handler for opcode: %d"):format(header.opcode) + end + + local status, data = self.socket:receive_buf(match.numbytes(header.total_body), true) + if ( not(status) ) then + return false, "Failed to receive data" + end + + local response = TAP.Response.Decoder[tonumber(header.opcode)]:new(data) + if ( not(response) ) then + return false, "Failed to parse response from server" + end + return true, response + end, + + -- Gets list of supported SASL authentication mechanisms + getSASLMechList = function(self) + return self:exch(TAP.Request.SASLList:new()) + end, + + -- Logins to the server + -- @param username string containing the username + -- @param password string containing the password + -- @param mech string containing the SASL mechanism to use + -- @return status true on success, false on failure + -- @return response string containing "Auth failure" on failure + login = function(self, username, password, mech) + mech = mech or self.mech or "PLAIN" + local status, response = self:exch(TAP.Request.Authenticate:new(username, password, mech)) + if ( not(status) ) then + return false, "Auth failure" + end + if ( response.status == "Auth failure" ) then + return false, response.status + end + return true, response.status + end, +} + + + +return _ENV; |