| Current Path : /usr/share/nmap/nselib/ |
| Current File : //usr/share/nmap/nselib/pgsql.lua |
---
-- PostgreSQL library supporting both version 2 and version 3 of the protocol.
-- The library currently contains the bare minimum to perform authentication.
-- Authentication is supported with or without SSL enabled and using the
-- plain-text or MD5 authentication mechanisms.
--
-- The PGSQL protocol is explained in detail in the following references.
-- * http://developer.postgresql.org/pgdocs/postgres/protocol.html
-- * http://developer.postgresql.org/pgdocs/postgres/protocol-flow.html
-- * http://developer.postgresql.org/pgdocs/postgres/protocol-message-formats.html
--
-- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html
-- @author "Patrik Karlsson <patrik@cqure.net>"
module(... or "pgsql",package.seeall)
-- Version 0.3
-- Created 02/05/2010 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>
-- Revised 02/20/2010 - v0.2 - added detectVersion to automaticaly detect and return
-- the correct version class
-- Revised 03/04/2010 - v0.3 - added support for trust authentication method
require("openssl")
require("bit")
--- Supported pgsql message types
MessageType = {
Error = 0x45,
BackendKeyData = 0x4b,
AuthRequest=0x52,
ParameterStatus = 0x53,
ReadyForQuery = 0x5a,
PasswordMessage = 0x70,
}
--- Supported authentication types
AuthenticationType = {
Success = 0x00,
Plain = 0x03,
MD5 = 0x05
}
-- Version 2 of the protocol
v2 =
{
--- Pad a string with zeroes
--
-- @param str string containing the string to be padded
-- @param len number containing the wanted length
-- @return string containing the padded string value
zeroPad = function(str, len)
local padding = len - str:len()
if ( padding < 0 ) then
return str
end
for i=1,padding do
str = str .. string.char(0x00)
end
return str
end,
messageDecoder = {
--- Decodes an Auth Request packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding, -1 on error
-- @return response table containing zero or more of the following <code>salt</code> and <code>success</code>
-- error string containing error message if pos is -1
[MessageType.AuthRequest] = function( data, len, pos )
local _, authtype
local response = {}
pos, authtype = bin.unpack(">I", data, pos)
if ( authtype == AuthenticationType.MD5 ) then
if ( len - pos + 1 ) < 3 then
return -1, "ERROR: Malformed AuthRequest received"
end
pos, response.salt = bin.unpack("A4", data, pos)
elseif ( authtype == AuthenticationType.Plain ) then
--do nothing
elseif ( authtype == 0 ) then
response.success = true
else
stdnse.print_debug( ("unknown auth type: %d"):format(authtype) )
end
response.authtype = authtype
return pos, response
end,
--- Decodes an Error packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding
-- @return response table containing zero or more of the following <code>error.severity</code>,
-- <code>error.code</code>, <code>error.message</code>, <code>error.file</code>,
-- <code>error.line</code> and <code>error.routine</code>
[MessageType.Error] = function( data, len, pos )
local tmp = data:sub(pos, pos + len - 4)
local response = {}
local pos_end = pos + len
response.error = {}
pos, response.error.message = bin.unpack("z", data, pos)
return pos, response
end,
},
--- Process the server response
--
-- @param data string containing the server response
-- @param pos number containing the offset into the data buffer
processResponse = function(data, pos)
local ptype, len, status, response
local pos = pos or 1
pos, ptype = bin.unpack("C", data, pos)
len = data:len() - 1
if v2.messageDecoder[ptype] then
pos, response = v2.messageDecoder[ptype](data, len, pos)
if pos ~= -1 then
response.type = ptype
return pos, response
end
else
stdnse.print_debug( ("Missing decoder for %d"):format(ptype) )
return -1, ("Missing decoder for %d"):format(ptype)
end
return -1, "Decoding failed"
end,
--- Reads a packet and handles additional socket reads to retrieve remaining data
--
-- @param socket socket already connected to the pgsql server
-- @param data string containing any data already retrieved from the socket
-- @param pos number containing the offset into the data buffer
-- @return data string containing the initial and any additional data
readPacket=function(socket, data, pos)
local pos = pos or 1
local data = data or ""
local status = true
local tmp = ""
local ptype, len
local catch = function() socket:close() stdnse.print_debug("processResponse(): failed") end
local try = nmap.new_try(catch)
if ( data == nil or data:len() == 0 ) then
data = try(socket:receive())
end
return data
end,
--- Sends a startup message to the server containing the username and database to connect to
--
-- @param socket socket already connected to the pgsql server
-- @param user string containing the name of the user
-- @param database string containing the name of the database
-- @return status true on success, false on failure
-- @return table containing a processed response from <code>processResponse</code>
-- string containing error message if status is false
sendStartup=function(socket, user, database)
local data, response, status, pos
local proto_ver, ptype, _, tmp
local tty, unused, args = "", "", ""
proto_ver = 0x0020000
user = v2.zeroPad(user, 32)
database = v2.zeroPad(database, 64)
data = bin.pack(">I>IAAAAA", 296, proto_ver, database, user, v2.zeroPad(args, 64), v2.zeroPad(unused, 64), v2.zeroPad(tty,64) )
socket:send( data )
-- attempt to verify version
status, data = socket:receive_bytes( 1 )
if ( not(status) ) then
return false, "sendStartup failed"
end
data = v2.readPacket(socket, data )
pos, response = v2.processResponse( data )
if ( pos < 0 or response.type == MessageType.Error) then
return false, response.error.message or "unknown error"
end
return true, response
end,
--- Attempts to authenticate to the pgsql server
-- Supports plain-text and MD5 authentication
--
-- @param socket socket already connected to the pgsql server
-- @param params table containing any additional parameters <code>authtype</code>, <code>version</code>
-- @param username string containing the username to use for authentication
-- @param password string containing the password to use for authentication
-- @param salt string containing the crypthographic salt value
-- @return status true on success, false on failure
-- @return result table containing parameter status information,
-- result string containing an error message if login fails
loginRequest = function ( socket, params, username, password, salt )
local catch = function() socket:close() stdnse.print_debug("loginRequest(): failed") end
local try = nmap.new_try(catch)
local response = {}
local status, data, len, pos, tmp
if ( params.authtype == AuthenticationType.MD5 ) then
local hash = createMD5LoginHash(username,password,salt)
data = bin.pack( ">Iz", 40, hash)
try( socket:send( data ) )
elseif ( params.authtype == AuthenticationType.Plain ) then
local data
data = bin.pack(">Iz", password:len() + 4, password)
try( socket:send( data ) )
elseif ( params.authtype == AuthenticationType.Success ) then
return true, nil
end
data, response.params = "", {}
data = v2.readPacket(socket, data, 1)
pos, tmp = v2.processResponse(data, 1)
-- this should contain the AuthRequest packet
if tmp.type ~= MessageType.AuthRequest then
return false, "Expected AuthRequest got something else"
end
if not tmp.success then
return false, "Login failure"
end
return true, response
end,
}
-- Version 3 of the protocol
v3 =
{
messageDecoder = {
--- Decodes an Auth Request packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding, -1 on error
-- @return response table containing zero or more of the following <code>salt</code> and <code>success</code>
-- error string containing error message if pos is -1
[MessageType.AuthRequest] = function( data, len, pos )
local _, authtype
local response = {}
pos, authtype = bin.unpack(">I", data, pos)
if ( authtype == AuthenticationType.MD5 ) then
if ( len - pos + 1 ) < 3 then
return -1, "ERROR: Malformed AuthRequest received"
end
pos, response.salt = bin.unpack("A4", data, pos)
elseif ( authtype == AuthenticationType.Plain ) then
--do nothing
elseif ( authtype == 0 ) then
response.success = true
else
stdnse.print_debug( "unknown auth type: %d", authtype )
end
response.authtype = authtype
return pos, response
end,
--- Decodes an ParameterStatus packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding
-- @return response table containing zero or more of the following <code>key</code> and <code>value</code>
[MessageType.ParameterStatus] = function( data, len, pos )
local tmp, _
local response = {}
tmp = data:sub(pos, pos + len - 4)
_, response.key, response.value = bin.unpack("zz", tmp)
return pos + len - 4, response
end,
--- Decodes an Error packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding
-- @return response table containing zero or more of the following <code>error.severity</code>,
-- <code>error.code</code>, <code>error.message</code>, <code>error.file</code>,
-- <code>error.line</code> and <code>error.routine</code>
[MessageType.Error] = function( data, len, pos )
local tmp = data:sub(pos, pos + len - 4)
local _, value, prefix
local response = {}
local pos_end = pos + len
response.error = {}
while ( pos < pos_end - 5 ) do
pos, prefix, value = bin.unpack("Az", data, pos)
if prefix == 'S' then
response.error.severity = value
elseif prefix == 'C' then
response.error.code = value
elseif prefix == 'M' then
response.error.message = value
elseif prefix == 'F' then
response.error.file = value
elseif prefix == 'L' then
response.error.line = value
elseif prefix == 'R' then
response.error.routine = value
end
end
return pos, response
end,
--- Decodes the BackendKeyData packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding, -1 on error
-- @return response table containing zero or more of the following <code>pid</code> and <code>key</code>
-- error string containing error message if pos is -1
[MessageType.BackendKeyData] = function( data, len, pos )
local response = {}
if len ~= 12 then
return -1, "ERROR: Invalid BackendKeyData packet"
end
pos, response.pid, response.key = bin.unpack(">I>I", data, pos)
return pos, response
end,
--- Decodes an ReadyForQuery packet
--
-- @param data string containing raw data recieved from socket
-- @param len number containing the length as retrieved from the header
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding, -1 on error
-- @return response table containing zero or more of the following <code>status</code>
-- error string containing error message if pos is -1
[MessageType.ReadyForQuery] = function( data, len, pos )
local response = {}
if len ~= 5 then
return -1, "ERROR: Invalid ReadyForQuery packet"
end
pos, response.status = bin.unpack("C", data, pos )
return pos, response
end,
},
--- Reads a packet and handles additional socket reads to retrieve remaining data
--
-- @param socket socket already connected to the pgsql server
-- @param data string containing any data already retrieved from the socket
-- @param pos number containing the offset into the data buffer
-- @return data string containing the initial and any additional data
readPacket = function(socket, data, pos)
local pos = pos or 1
local data = data or ""
local status = true
local tmp = ""
local ptype, len
local header
local catch = function() socket:close() stdnse.print_debug("processResponse(): failed") end
local try = nmap.new_try(catch)
if ( data:len() - pos < 5 ) then
status, tmp = socket:receive_bytes( 5 - ( data:len() - pos ) )
end
if not status then
return nil, "Failed to read packet"
end
if tmp:len() ~= 0 then
data = data .. tmp
end
pos, header = v3.decodeHeader(data,pos)
while data:len() < header.len do
data = data .. try(socket:receive_bytes( ( header.len + 1 ) - data:len() ))
end
return data
end,
--- Decodes the postgres header
--
-- @param data string containing the server response
-- @param pos number containing the offset into the data buffer
-- @return pos number containing the offset after decoding
-- @return header table containing <code>type</code> and <code>len</code>
decodeHeader = function(data, pos)
local ptype, len
pos, ptype, len = bin.unpack("C>I", data, pos)
return pos, { ['type'] = ptype, ['len'] = len }
end,
--- Process the server response
--
-- @param data string containing the server response
-- @param pos number containing the offset into the data buffer
-- @return pos number containing offset after decoding
-- @return response string containing decoded data
-- error message if pos is -1
processResponse = function(data, pos)
local ptype, len, status, response
local pos = pos or 1
local header
pos, header = v3.decodeHeader( data, pos )
if v3.messageDecoder[header.type] then
pos, response = v3.messageDecoder[header.type](data, header.len, pos)
if pos ~= -1 then
response.type = header.type
return pos, response
end
else
stdnse.print_debug( "Missing decoder for %d", header.type )
return -1, ("Missing decoder for %d"):format(header.type)
end
return -1, "Decoding failed"
end,
--- Attempts to authenticate to the pgsql server
-- Supports plain-text and MD5 authentication
--
-- @param socket socket already connected to the pgsql server
-- @param params table containing any additional parameters <code>authtype</code>, <code>version</code>
-- @param username string containing the username to use for authentication
-- @param password string containing the password to use for authentication
-- @param salt string containing the crypthographic salt value
-- @return status true on success, false on failure
-- @return result table containing parameter status information,
-- result string containing an error message if login fails
loginRequest = function ( socket, params, username, password, salt )
local catch = function() socket:close() stdnse.print_debug("loginRequest(): failed") end
local try = nmap.new_try(catch)
local response, header = {}, {}
local status, data, len, tmp, _
local pos = 1
if ( params.authtype == AuthenticationType.MD5 ) then
local hash = pgsql.createMD5LoginHash(username, password, salt)
data = bin.pack( "C>Iz", MessageType.PasswordMessage, 40, hash )
try( socket:send( data ) )
elseif ( params.authtype == AuthenticationType.Plain ) then
local data
data = bin.pack("C>Iz", MessageType.PasswordMessage, password:len() + 4, password)
try( socket:send( data ) )
elseif ( params.authtype == AuthenticationType.Success ) then
return true, nil
end
data, response.params = "", {}
data = v3.readPacket(socket, data, 1)
pos, tmp = v3.processResponse(data, 1)
-- this should contain the AuthRequest packet
if tmp.type ~= MessageType.AuthRequest then
return false, "Expected AuthRequest got something else"
end
if not tmp.success then
return false, "Login failure"
end
repeat
data = v3.readPacket(socket, data, pos)
pos, tmp = v3.processResponse(data, pos)
if ( tmp.type == MessageType.ParameterStatus ) then
table.insert(response.params, {name=tmp.key, value=tmp.value})
end
until pos >= data:len() or pos == -1
return true, response
end,
--- Sends a startup message to the server containing the username and database to connect to
--
-- @param socket socket already connected to the pgsql server
-- @param user string containing the name of the user
-- @param database string containing the name of the database
-- @return status true on success, false on failure
-- @return table containing a processed response from <code>processResponse</code>
-- string containing error message if status is false
sendStartup = function(socket, user, database )
local data, response, status, pos
local proto_ver, ptype, _, tmp
proto_ver = 0x0030000
data = bin.pack(">IzzzzH", proto_ver, "user", user, "database", database, 0)
data = bin.pack(">I", data:len() + 4) .. data
socket:send( data )
-- attempt to verify version
status, data = socket:receive_bytes( 2 )
if ( not(status) ) then
return false, "sendStartup failed"
end
if ( not(status) or data:match("^EF") ) then
return false, "Incorrect version"
end
data = v3.readPacket(socket, data )
pos, response = v3.processResponse( data )
if ( pos < 0 or response.type == MessageType.Error) then
return false, response.error.message or "unknown error"
end
return true, response
end
}
--- Sends a packet requesting SSL communication to be activated
--
-- @param socket socket already connected to the pgsql server
-- @return boolean true if request was accepted, false if request was denied
function requestSSL(socket)
-- SSLRequest
local ssl_req_code = 80877103
local data = bin.pack( ">I>I", 8, ssl_req_code)
local status, response
socket:send(data)
status, response = socket:receive_bytes(1)
if ( not(status) ) then
return false
end
if ( response == 'S' ) then
return true
end
return false
end
--- Creates a cryptographic hash to be used for login
--
-- @param username username
-- @param password password
-- @param salt salt
-- @return string suitable for login request
function createMD5LoginHash(username, password, salt)
local md5_1 = select( 2, bin.unpack( "H16", openssl.md5(password..username) ) ):lower()
return "md5" .. select( 2, bin.unpack("H16", openssl.md5( md5_1 .. salt ) ) ):lower()
end
--- Prints the contents of the error table returned from the Error message decoder
--
-- @param dberror table containing the error
function printErrorMessage( dberror )
if not dberror then
return
end
for k, v in pairs(dberror) do
stdnse.print_debug( ("%s=%s"):format(k, v) )
end
end
--- Attempts to determine if the server supports v3 or v2 of the protocol
--
-- @param host table
-- @param port table
-- @return class v2 or v3
function detectVersion(host, port)
local status, response
local socket = nmap.new_socket()
socket:connect(host, port)
status, response = v3.sendStartup(socket, "versionprobe", "versionprobe")
socket:close()
if ( not(status) and response == 'Incorrect version' ) then
return v2
end
return v3
end
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