Re: [NSE Script] MySQL Server Information

[Kris Katterjohn <katterjohn () gmail com>]

jah wrote:
> On 19/12/2007 02:25, Kris Katterjohn wrote:
> > Yeah, that sounds good.  We can work with Thomas on the improved 
> > script; remember, it requires the SSL bindings.
> >
> > For now though, if anybody thinks so and I'm given the go I'll commit 
> > the new script as-is.  Unless we have any other suggestions! :)
> Aye!

I always say things like "as-is", but I never seem to mean it :)

I've attached a modified script, but it's nothing too major:

- Updated some comments around the script
- Localized some functions
- Fixed some whitespace issues
- A slight reorder of 'offset' around the protocol/error check
- Removed extra "\n" newlines from 'output' which don't actually get 
printed by NSE

Unless a bug is found or new suggestion is made, this is what would be 
committed if Fyodor chimes in with a yes (he probably won't mind since 
it's a script, but just in case).

Thanks again for your help, Jah!

Kris Katterjohn

-- Connect to MySQL server and print information such as the protocol and
-- version numbers, thread id, status, capabilities and the password salt

-- If service detection is performed and the server appears to be blocking
-- our host or is blocked from too many connections, then we don't bother
-- running this script (see the portrule)

-- Many thanks to jah (jah () zadkiel plus com) for testing and enhancements

id = "MySQL Server Information"

description = "Connects to a MySQL server and prints information"

author = "Kris Katterjohn <katterjohn () gmail com>"

license = "Look at Nmap's COPYING"

categories = { "discovery", "safe" }

require 'bit'

-- Grabs NUL-terminated string
local getstring = function(orig)
        local str = ""
        local index = 1

        while orig:byte(index) ~= 0 do
                str = str .. string.char(orig:byte(index))

                index = index + 1
        end

        return str
end

-- Convert two bytes into a number
local ntohs = function(num)
        local b1 = bit.band(num:byte(1), 255)
        local b2 = bit.band(num:byte(2), 255)

        return bit.bor(b1, bit.lshift(b2, 8))
end

-- Convert three bytes into a number
local ntoh3 = function(num)
        local b1 = bit.band(num:byte(1), 255)
        local b2 = bit.band(num:byte(2), 255)
        local b3 = bit.band(num:byte(3), 255)

        return bit.bor(b1, bit.lshift(b2, 8), bit.lshift(b3, 16))
end

-- Convert four bytes into a number
local ntohl = function(num)
        local b1 = bit.band(num:byte(1), 255)
        local b2 = bit.band(num:byte(2), 255)
        local b3 = bit.band(num:byte(3), 255)
        local b4 = bit.band(num:byte(4), 255)

        return bit.bor(b1, bit.lshift(b2, 8), bit.lshift(b3, 16), bit.lshift(b4, 24))
end

-- Convert number to a list of capabilities for printing
local capabilities = function(num)
        local caps = ""

        if bit.band(num, 1) > 0 then
                caps = caps .. "Long Passwords, "
        end

        if bit.band(num, 8) > 0 then
                caps = caps .. "Connect with DB, "
        end

        if bit.band(num, 32) > 0 then
                caps = caps .. "Compress, "
        end

        if bit.band(num, 64) > 0 then
                caps = caps .. "ODBC, "
        end

        if bit.band(num, 2048) > 0 then
                caps = caps .. "SSL, "
        end

        if bit.band(num, 8192) > 0 then
                caps = caps .. "Transactions, "
        end

        if bit.band(num, 32768) > 0 then
                caps = caps .. "Secure Connection, "
        end

        return caps:gsub(", $", "")
end

portrule = function(host, port)
        local extra = port.version.extrainfo

        if
                (port.number == 3306
                or port.service == "mysql")
                and port.protocol == "tcp"
                and port.state == "open"
                and not (extra ~= nil
                        and (extra:match("[Uu]nauthorized")
                                or extra:match("[Tt]oo many connection")))
        then
                return true
        end

        return false
end

action = function(host, port)
        local sock
        local response = ""
        local output = ""

        sock = nmap.new_socket()

        sock:set_timeout(5000)

        sock:connect(host.ip, port.number)

        while true do
                local status, line = sock:receive_lines(1)

                if not status then
                        break
                end

                response = response .. line
        end

        sock:close()

        local length = ntoh3(response:sub(1, 3))

        if length ~= response:len() - 4 then
                return "Invalid greeting (Not MySQL?)"
        end

        -- Keeps track of where we are in the binary data
        local offset = 1 + 4

        local protocol = response:byte(offset)

        offset = offset + 1

        -- If a 0xff is here instead of the protocol, an error occurred.
        -- Pass it along to the user..
        if (protocol == 255) then
                output = "MySQL Error detected!\n"

                local sqlerrno = ntohs(response:sub(offset, offset + 2))

                offset = offset + 2

                local sqlerrstr = response:sub(offset)

                output = output .. "Error Code was: " .. sqlerrno .. "\n"

                output = output .. sqlerrstr

                return output
        end

        local version = getstring(response:sub(offset))

        offset = offset + version:len() + 1

        local threadid = ntohl(response:sub(offset, offset + 4))

        offset = offset + 4

        local salt = getstring(response:sub(offset))

        offset = offset + salt:len() + 1

        local caps = capabilities(ntohs(response:sub(offset, offset + 2)))

        offset = offset + 2

        offset = offset + 1

        local status = ""

        if ntohs(response:sub(offset, offset + 2)) == 2 then
                status = "Autocommit"
        end

        offset = offset + 2

        offset = offset + 13 -- unused

        if response:len() - offset + 1 == 13 then
                salt = salt .. getstring(response:sub(offset))
        end

        output = output .. "Protocol: " .. protocol .. "\n"
        output = output .. "Version: " .. version .. "\n"
        output = output .. "Thread ID: " .. threadid .. "\n"

        if caps:len() > 0 then
                output = output .. "Some Capabilities: " .. caps .. "\n"
        end

        if status:len() > 0 then
                output = output .. "Status: " .. status .. "\n"
        end

        output = output .. "Salt: " .. salt .. "\n"

        return output
end


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