local _G = require "_G"
local mysql = require "mysql"
local nmap = require "nmap"
local shortport = require "shortport"
local stdnse = require "stdnse"
local table = require "table"

description = [[
Audits MySQL database server security configuration against parts of
the CIS MySQL v1.0.2 benchmark (the engine can be used for other MySQL
audits by creating appropriate audit files).
]]


---
-- @usage
-- nmap -p 3306 --script mysql-audit --script-args "mysql-audit.username='root', \
-- 	mysql-audit.password='foobar',mysql-audit.filename='nselib/data/mysql-cis.audit'"
--
-- @args mysql-audit.username the username with which to connect to the database
-- @args mysql-audit.password the password with which to connect to the database
-- @args mysql-audit.filename the name of the file containing the audit rulebase
--
-- @output
-- PORT     STATE SERVICE
-- 3306/tcp open  mysql
-- | mysql-audit: 
-- |   CIS MySQL Benchmarks v1.0.2
-- |       3.1: Skip symbolic links => PASS
-- |       3.2: Logs not on system partition => PASS
-- |       3.2: Logs not on database partition => PASS
-- |       4.1: Supported version of MySQL => REVIEW
-- |         Version: 5.1.54-1ubuntu4
-- |       4.4: Remove test database => PASS
-- |       4.5: Change admin account name => FAIL
-- |       4.7: Verify Secure Password Hashes => PASS
-- |       4.9: Wildcards in user hostname => FAIL
-- |         The following users were found with wildcards in hostname
-- |           root
-- |           super
-- |           super2
-- |       4.10: No blank passwords => PASS
-- |       4.11: Anonymous account => PASS
-- |       5.1: Access to mysql database => REVIEW
-- |         Verify the following users that have access to the MySQL database
-- |           user              host
-- |           root              localhost
-- |           root              patrik-11
-- |           root              127.0.0.1
-- |           debian-sys-maint  localhost
-- |           root              %
-- |           super             %
-- |       5.2: Do not grant FILE privileges to non Admin users => REVIEW
-- |         The following users were found having the FILE privilege
-- |           super
-- |           super2
-- |       5.3: Do not grant PROCESS privileges to non Admin users => REVIEW
-- |         The following users were found having the PROCESS privilege
-- |           super
-- |       5.4: Do not grant SUPER privileges to non Admin users => REVIEW
-- |         The following users were found having the SUPER privilege
-- |           super
-- |       5.5: Do not grant SHUTDOWN privileges to non Admin users => REVIEW
-- |         The following users were found having the SHUTDOWN privilege
-- |           super
-- |       5.6: Do not grant CREATE USER privileges to non Admin users => REVIEW
-- |         The following users were found having the CREATE USER privilege
-- |           super
-- |       5.7: Do not grant RELOAD privileges to non Admin users => REVIEW
-- |         The following users were found having the RELOAD privilege
-- |           super
-- |       5.8: Do not grant GRANT privileges to non Admin users => PASS
-- |       6.2: Disable Load data local => FAIL
-- |       6.3: Disable old password hashing => PASS
-- |       6.4: Safe show database => FAIL
-- |       6.5: Secure auth => FAIL
-- |       6.6: Grant tables => FAIL
-- |       6.7: Skip merge => FAIL
-- |       6.8: Skip networking => FAIL
-- |       6.9: Safe user create => FAIL
-- |       6.10: Skip symbolic links => FAIL
-- |       
-- |_      The audit was performed using the db-account: root

-- Version 0.1
-- Created 05/29/2011 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>

author = "Patrik Karlsson"
license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
categories = {"discovery", "safe"}


portrule = shortport.port_or_service(3306, "mysql")
local TEMPLATE_NAME, ADMIN_ACCOUNTS = "", ""

local function loadAuditRulebase( filename )
	local rules = {}

	local env = setmetatable({
		test = function(t) table.insert(rules, t) end;
	}, {__index = _G})

	local file, err = loadfile(filename, "t", env)

	if ( not(file) ) then
		return false, ("ERROR: Failed to load rulebase:\n%s"):format(err)
	end
	
	
	file()
	TEMPLATE_NAME = env.TEMPLATE_NAME
	ADMIN_ACCOUNTS = env.ADMIN_ACCOUNTS
	return true, rules
end

action = function( host, port )

	local username = stdnse.get_script_args("mysql-audit.username")
	local password = stdnse.get_script_args("mysql-audit.password")
	local filename = stdnse.get_script_args("mysql-audit.filename")

	if ( not(filename) ) then
		return "\n  No audit rulebase file was supplied (see mysql-audit.filename)"
	end

	if ( not(username) ) then
		return "\n  No username was supplied (see mysql-audit.username)"
	end

	local status, tests = loadAuditRulebase( filename )
	if( not(status) ) then return tests end

	local socket = nmap.new_socket()
	status = socket:connect(host, port)

	local response
	status, response = mysql.receiveGreeting( socket )
	if ( not(status) ) then return response end
	
	status, response = mysql.loginRequest( socket, { authversion = "post41", charset = response.charset }, username, password, response.salt )

	if ( not(status) ) then return "ERROR: Failed to authenticate" end
	local results = {}

	for _, test in ipairs(tests) do
		local queries = ( "string" == type(test.sql) ) and { test.sql } or test.sql
		local rowstab = {}
		
		for _, query in ipairs(queries) do
			local row
			status, row = mysql.sqlQuery( socket, query )
			if ( not(status) ) then
				table.insert( results, { ("%s: ERROR: Failed to execute SQL statement"):format(test.id) } )
			else
				table.insert(rowstab, row)
			end
		end
		
		if ( #rowstab > 0 ) then
			local result_part = {}
			local res = test.check(rowstab)
			local status, data = res.status, res.result
			status = ( res.review and "REVIEW" ) or (status and "PASS" or "FAIL")
			
			table.insert( result_part, ("%s: %s => %s"):format(test.id, test.desc, status) )
			if ( data ) then
				table.insert(result_part, { data } )
			end
			table.insert( results, result_part )
		end
	end

	socket:close()
	results.name = TEMPLATE_NAME

	table.insert(results, "")
	table.insert(results, {name = "Additional information", ("The audit was performed using the db-account: %s"):format(username),
		("The following admin accounts were excluded from the audit: %s"):format(stdnse.strjoin(",", ADMIN_ACCOUNTS))
	})

	return stdnse.format_output(true, { results })
end