I am trying to read the following stream:
127.0.0.1:6379> xrevrange driver:70 + - count 1
1) 1) "1656531417451-0"
2) 1) "field1"
2) "value1"
3) "isbusy"
4) "true"
How can I read this stream in Lua script and reflect the field isbusy from the stream into the the local Lua variable is_busy?
I could not get my head around Lua collections.
local stream = KEYS[1]
local is_busy = false
local messages = redis.call("XREVRANGE", stream, "+", "-", "COUNT", "1")
for _, message in ipairs(messages) do
end
You need to parse the nested structure:
local id
for _, message in ipairs(messages) do
for i, sub_msg in ipairs(message) do
if i == 1 then
id = sub_msg
else
-- parse attributes
local i = 1
while i < #sub_msg do
local k = sub_msg[i]
local v = sub_msg[i + 1]
if k == "isbusy" then
is_busy = v
end
i = i + 2
end
end
end
end
Related
Can anyone on here help me on decrypting the SSL encryption that protects this LUA script linked at the end of this topic? Basically they are encoded with Base64 then SSL, but I have no idea how to do the SSL portion. They are used with a program called Bot of Legends, and someone told me that it is possible to break the encryption by dumping the decryption function of said program and using that to get the SSL key, but I have no clue where to even start on that. Basically these scripts work by connecting to an authentication server that is coded into the script, and I have gotten a few on my own by sniffing the traffic to their auth server from network packets to get their server link and essentially created my own auth server with Apache, then redirected the network traffic that goes to their server to my own from the script to get the script validated response. For some scripts that have stronger encryption, its not that easy and I would have to get to the source code to remove the coding that runs the auth server checks. Up until a few days ago I had no knowledge on how lua coding worked and how to even compute how auth server checks could be even possible for coding in a simple text file due to lua obfuscation. So bear with me, I would like if someone can chime in and give me an idea on what I can do.
Regards,
Chris
*** PasteBin link to the script in question in raw format: http://pastebin.com/raw.php?i=bG0VqQGW
The Base64 section is first with the SSL section at the bottom.
print("SSL Decoder version 2.0")
print("Copyright (C) 2015")
print("Decoding Started...")
local infilename = select(1,...)
local outfilename = select(2,...)
local infile = io.open(infilename, "r")
if not infile then
error("Failed to open input file.")
end
local intext = infile:read("*a")
infile:close()
local ssltabletext = intext:match("SSL%s*%(%s*%{([%s,0-9]*)%}%s*%)")
if not ssltabletext then
error("Could not find ssl table in source file.")
end
local ssltable = load("return {"..ssltabletext.."}")()
if #ssltable < 255 then
error("SSL table is too short -- can't find table encryption key.")
end
-- find decryption key for the ssl table
local decrypt = {}
decrypt[0] = 0
for i = 1,255 do
local dec = i
local enc = ssltable[i]
assert(decrypt[enc] == nil)
decrypt[enc] = dec
end
-- decrypt ssl table
for i = 256, #ssltable - 256 do -- not sure what last 256 bytes are
ssltable[i] = decrypt[ssltable[i] ]
end
-- If this does a stack overflow, easy to change to something dumb but more robust
local sslcode = string.char(table.unpack(ssltable, 256, #ssltable - 256))
-- This is interesting --
--print(sslcode)
local keyindex = sslcode:match("local Key%s*=%s*'()")
if not keyindex then
error("Could not find key in decoded ssl table.")
end
local key = sslcode:sub(keyindex)
local length = 0
while true do
local c = key:sub(length+1, length+1)
if c == "" then
error("Key string was not terminated.")
elseif c == "'" then
break
elseif c == "\\" then
local c2 = key:sub(length+2, length+2)
if c2:match("%d") then
local c3 = key:sub(length+3, length+3)
if c3:match("%d") then
local c4 = key:sub(length+4, length+4)
if c4:match("%d") then
length = length + 4
else
length = length + 3
end
else
length = length + 2
end
elseif c2 == "x" then
length = length + 4
else
length = length + 2
end
else
length = length + 1
end
end
key = key:sub(1, length)
if #key == 0 then
error("Key is empty")
end
print("Key Found! > " .. key)
print("Decoding finished, outfile is at > " .. outfilename)
-- find base64
local b64 = intext:match("_G.ScriptCode%s*=%s*Base64Decode%s*%(%s*\"([a-zA-Z0-9/+]*=*)\"%s*%)")
if not b64 then
error("Could not find Base-64 encrypted code in source file.")
end
-- base64 decode
local b64val = {}
for i = 0, 25 do
do
local letter = string.byte("A")
b64val[string.char(letter+i)] = i
end
do
local letter = string.byte("a")
b64val[string.char(letter+i)] = i + 26
end
end
for i = 0, 9 do
local numeral = string.byte("0")
b64val[string.char(numeral+i)] = i + 52
end
b64val["+"] = 62
b64val["/"] = 63
b64val["="] = 0
local encoded = b64:gsub("(.)(.)(.)(.)",function(a,b,c,d)
local n = b64val[a] * (64 * 64 * 64) + b64val[b] * (64 * 64) + b64val[c] * 64 + b64val[d]
local b1 = n % 256; n = (n - b1) / 256
local b2 = n % 256; n = (n - b2) / 256
local b3 = n
if d == "=" then
if c == "=" then
assert(b1 == 0 and b2 == 0)
return string.char(b3)
else
assert(b1 == 0)
return string.char(b3, b2)
end
else
return string.char(b3, b2, b1)
end
end)
-- decode
local decoded = encoded:gsub("()(.)", function(i, c)
local b = c:byte()
local ki = ((i - 1) % #key) + 1
local k = key:byte(ki,ki)
b = b - k
if b < 0 then b = b + 256 end
return string.char(b)
end)
-- verify
local result, err = load(decoded)
if not result then
error("Decoded file could not be loaded -- it may be corrupt... ("..tostring(err)..")")
end
-- output
local outfile = io.open(outfilename, "wb")
if not outfile then
error("Failed to open output file.")
end
outfile:write(decoded)
outfile:close()
This code is by Extreme Coders (https://reverseengineering.stackexchange.com/users/1413/extreme-coders)
how to use it , u need to get lua52.exe
save the code into a text file and name it ssl.lua (for example)
now run cmd and type lua52 ssl yourscript.lua decryptedscript.lua
it will run and decrypt it.
I have two tables in lua (In production, a has 18 elements and b has 8):
local a = {1,2,3,4,5,6}
local b = {3,5,7,8,9}
I need to return 'a' omitting any common elements from 'b' -- {1,2,4,6} similar to the ruby command a-b (if a and b were arrays).
The best lua logic I have been able to come up with is:
local function find(a, tbl)
for _,a_ in ipairs(tbl) do if a_==a then return true end end
end
function difference(a, b)
local ret = {}
for _,a_ in ipairs(a) do
if not find(a_,b) then table.insert(ret, a_) end
end
return ret
end
local a = {1,2,3,4,5,6}
local b = {3,5,7,8,9}
local temp = {}
temp = difference(a,b)
print(temp[1],temp[2],temp[3],temp[4])
I need to loop through these table comparison pretty quick (min 10K times a second in production). Is there a cleaner way to do this?
======
This is part of a redis server side script and I have to protect my Redis CPU. Outside of a clean Lua process I have two other options:
1.Create two redis temp keys then run sinter for a big(O) of 42
18 sadd(a)
8 sadd(b)
16 sinter(a,b)
2.Return both a and b to ruby do the array comparison and send back the result.
Network cost of the back and fourth of a few thousand connections a second will be a drain on resources.
Try this:
function difference(a, b)
local aa = {}
for k,v in pairs(a) do aa[v]=true end
for k,v in pairs(b) do aa[v]=nil end
local ret = {}
local n = 0
for k,v in pairs(a) do
if aa[v] then n=n+1 ret[n]=v end
end
return ret
end
You could do this (not tested):
function difference(a, b)
local ai = {}
local r = {}
for k,v in pairs(a) do r[k] = v; ai[v]=true end
for k,v in pairs(b) do
if ai[v]~=nil then r[k] = nil end
end
return r
end
If you can modify a then it is even shorter:
function remove(a, b)
local ai = {}
for k,v in pairs(a) do ai[v]=true end
for k,v in pairs(b) do
if ai[v]~=nil then a[k] = nil end
return r
end
If your tables are sorted you could also do a parallel sweep of the two tables together, something like the following pseudo code:
function diff(a, b)
Item = front of a
Diff = front of b
While Item and Diff
If Item < Diff then
Item is next of a
Else if Item == Diff then
remove Item from a
Item = next of a
Diff = next of b
Else # else Item > Diff
Diff = next of b
This doesn't use any extra tables. Even if you want new table instead of in-place diff, only one new table. I wonder how it would compare to the hash table method (remove).
Note that it doesn't matter how many times you loop, if a and b are small then there will be no major difference between these and your alg. You'll need at least 100 items in a and in b, maybe even 1000.
Maybe something like that:
function get_diff (t1, t2)
local diff = {}
local bool = false
for i, v in pairs (t1) do
if t2 and type (v) == "table" then
local deep_diff = get_diff (t1[i], t2[i])
if deep_diff then
diff[i] = deep_diff
bool = true
end
elseif t2 then
if not (t1[i] == t2[i]) then
diff[i] = t1[i] .. ' -- not [' .. t2[i] .. ']'
bool = true
end
else
diff[i] = t1[i]
bool = true
end
end
if bool then
return diff
end
end
local t1 = {1, 2, 3, {1, 2, 3}}
local t2 = {1, 2, 3, {1, 2, 4}}
local diff = get_diff (t1, t2)
Result:
diff = {
nil,
nil,
nil,
{
[3] = "3 -- not [4]"
}
}
This question already has answers here:
method for serializing lua tables
(5 answers)
Closed 8 years ago.
I would like to serialize a table so that I can insert it into a database and retrieve it later on. How would I do this?
maybe like this https://gist.github.com/rangercyh/5814003
local szStr = ""
function print_lua_table (lua_table, indent)
indent = indent or 0
for k, v in pairs(lua_table) do
if type(k) == "string" then
k = string.format("%q", k)
end
local szSuffix = ""
if type(v) == "table" then
szSuffix = "{"
end
local szPrefix = string.rep(" ", indent)
formatting = szPrefix.."["..k.."]".." = "..szSuffix
if type(v) == "table" then
szStr = szStr..formatting
print_lua_table(v, indent + 1)
szStr = szStr..szPrefix.."},"
else
local szValue = ""
if type(v) == "string" then
szValue = string.format("%q", v)
else
szValue = tostring(v)
end
szStr = szStr..formatting..szValue..","
end
end
end
How to serialize Lua value nicely?
local serialize
do
local num_fmt = '%.17g'
local NaN_serialized = { -- This idea was stolen from lua-nucleo
[num_fmt:format(1/0)] = '1/0',
[num_fmt:format(-1/0)] = '-1/0',
[num_fmt:format(0/0)] = '0/0'
}
local function serialize_table(t, indent)
indent = indent or ''
local new_indent = indent..'\t'
if next(t) == nil then
return '{}'
else
local lines = {}
local function add_line(key)
local ser_key = key
if type(key) ~= 'string' or not key:find'^[%a_][%w_]*$' then
ser_key = '['..serialize(key, new_indent)..']'
end
table.insert(lines,
ser_key..' = '..serialize(t[key], new_indent))
end
local other_keys = {}
local keys = setmetatable({number = {}, string = {}},
{__index = function() return other_keys end})
for k in pairs(t) do
table.insert(keys[type(k)], k)
end
table.sort(keys.number)
table.sort(keys.string)
for _, k in ipairs(keys.number) do
add_line(k)
end
for _, k in ipairs(keys.string) do
add_line(k)
end
for _, k in ipairs(other_keys) do
add_line(k)
end
return '{\n'..new_indent..table.concat(lines, ',\n'..new_indent)
..'\n'..indent..'}'
end
end
function serialize(v, indent)
if type(v) == 'string' then
return ('%q'):format(v)
elseif type(v) == 'boolean' then
return tostring(v)
elseif type(v) == 'nil' then
return tostring(v)
elseif type(v) == 'number' then
return (num_fmt:format(v):gsub('^.*', NaN_serialized))
elseif type(v) == 'table' then
return serialize_table(v, indent)
else
error('Can not serialize '..type(v))
end
end
end
-- What it can:
print(serialize(math.huge))
print(serialize'"What\'s up?"\n\t123')
print(serialize{{}, {{}}})
-- And what it can not:
local t = {}
local tt = {[t] = t}
print(serialize(tt)) -- tt is not a tree, so it was serialized incorrectly
Hello I am building a console application in VB.NET that reads a record file and outputs it to the user. I have gotten the program to output all of the records to the console but I cannot seem to get the search function working.
I want the user to input the record number and for the program to search the text file for that specific record and then output it to the console.
I will leave the read record function here for reference.
Read Records function:
Public Function Read_Records()
File_Name = "drecords.txt"
File_num = FreeFile()
Record_Counter = 0
record_no = 999
If File_Name <> "" Then
Try
FileOpen(File_num, File_Name, OpenMode.Input)
Do Until EOF(File_num)
Record_Counter = Record_Counter + 1
record_no = record_no + 1
records(Record_Counter, 0) = record_no
records(Record_Counter, 1) = LineInput(File_num)
records(Record_Counter, 2) = LineInput(File_num)
records(Record_Counter, 3) = LineInput(File_num)
records(Record_Counter, 4) = LineInput(File_num)
records(Record_Counter, 5) = LineInput(File_num)
Loop
record_ID = Record_Counter
Catch ex As Exception
MsgBox("ERROR OPENING FILE")
Finally
FileClose(File_num)
End Try
End If
Last_Record = Record_Counter
Return records
End Function
I'm not sure exactly what you want, but here are a few examples.
To read a record number from the console and output that record, do something like this:
dim i, k as integer
k = val(console.readline())
for i = 1 to 5
console.writeline(records(k, i))
next i
I'm not sure how else you would identify the record, but, for example, you can search the records for a value of "abc" in the first field like this:
For i = 1 to Last_Record
if records(i, 1) = "abc" then
' output the record to the user
end if
next i
Replace records(i, 1) with records(i, 0) to search for a record number.
If you want to search each field, you can add a nested loop:
For i = 1 to Last_Record
for k = 1 to 5
if records(i, k) = "abc" then
' output the record to the user
end if
next k
next i
I am wanting to convert a 2d lua table into a string, then after converting it to a string convert it back into a table using that newly created string. It seems as if this process is called serialization, and is discussed in the below url, yet I am having a difficult time understanding the code and was hoping someone here had a simple table.toString and table.fromString function
http://lua-users.org/wiki/TableSerialization
I am using the following code in order to serialize tables:
function serializeTable(val, name, skipnewlines, depth)
skipnewlines = skipnewlines or false
depth = depth or 0
local tmp = string.rep(" ", depth)
if name then tmp = tmp .. name .. " = " end
if type(val) == "table" then
tmp = tmp .. "{" .. (not skipnewlines and "\n" or "")
for k, v in pairs(val) do
tmp = tmp .. serializeTable(v, k, skipnewlines, depth + 1) .. "," .. (not skipnewlines and "\n" or "")
end
tmp = tmp .. string.rep(" ", depth) .. "}"
elseif type(val) == "number" then
tmp = tmp .. tostring(val)
elseif type(val) == "string" then
tmp = tmp .. string.format("%q", val)
elseif type(val) == "boolean" then
tmp = tmp .. (val and "true" or "false")
else
tmp = tmp .. "\"[inserializeable datatype:" .. type(val) .. "]\""
end
return tmp
end
the code created can then be executed using loadstring(): http://www.lua.org/manual/5.1/manual.html#pdf-loadstring if you have passed an argument to 'name' parameter (or append it afterwards):
s = serializeTable({a = "foo", b = {c = 123, d = "foo"}})
print(s)
a = loadstring(s)()
The code lhf posted is a much simpler code example than anything from the page you linked, so hopefully you can understand it better. Adapting it to output a string instead of printing the output looks like:
t = {
{11,12,13},
{21,22,23},
}
local s = {"return {"}
for i=1,#t do
s[#s+1] = "{"
for j=1,#t[i] do
s[#s+1] = t[i][j]
s[#s+1] = ","
end
s[#s+1] = "},"
end
s[#s+1] = "}"
s = table.concat(s)
print(s)
The general idea with serialization is to take all the bits of data from some data structure like a table, and then loop through that data structure while building up a string that has all of those bits of data along with formatting characters.
How about a JSON module? That way you have also a better exchangeable data. I usually prefer dkjson, which also supports utf-8, where cmjjson won't.
Under the kong works this
local cjson = require "cjson"
kong.log.debug(cjson.encode(some_table))
Out of the kong should be installed package lua-cjson https://github.com/openresty/lua-cjson/
Here is a simple program which assumes your table contains numbers only. It outputs Lua code that can be loaded back with loadstring()(). Adapt it to output to a string instead of printing it out. Hint: redefine print to collect the output into a table and then at the end turn the output table into a string with table.concat.
t = {
{11,12,13},
{21,22,23},
}
print"return {"
for i=1,#t do
print"{"
for j=1,#t[i] do
print(t[i][j],",")
end
print"},"
end
print"}"
Assuming that:
You don't have loops (table a referencing table b and b referencing a)
Your tables are pure arrays (all keys are consecutive positive integers, starting on 1)
Your values are integers only (no strings, etc)
Then a recursive solution is easy to implement:
function serialize(t)
local serializedValues = {}
local value, serializedValue
for i=1,#t do
value = t[i]
serializedValue = type(value)=='table' and serialize(value) or value
table.insert(serializedValues, serializedValue)
end
return string.format("{ %s }", table.concat(serializedValues, ', ') )
end
Prepend the string resulting from this function with a return, store it on a .lua file:
-- myfile.lua
return { { 1, 2, 3 }, { 4, 5, 6 } }
You can just use dofile to get the table back.
t = dofile 'myfile.lua'
Notes:
If you have loops, then you will have
to handle them explicitly - usually with an extra table to "keep track" of repetitions
If you don't have pure arrays, then
you will have to parse t differently,
as well as handle the way the keys are rendered (are they strings? are they other tables? etc).
If you have more than just integers
and subtables, then calculating
serializedValue will be more
complex.
Regards!
I have shorter code to convert table to string but not reverse
function compileTable(table)
local index = 1
local holder = "{"
while true do
if type(table[index]) == "function" then
index = index + 1
elseif type(table[index]) == "table" then
holder = holder..compileTable(table[index])
elseif type(table[index]) == "number" then
holder = holder..tostring(table[index])
elseif type(table[index]) == "string" then
holder = holder.."\""..table[index].."\""
elseif table[index] == nil then
holder = holder.."nil"
elseif type(table[index]) == "boolean" then
holder = holder..(table[index] and "true" or "false")
end
if index + 1 > #table then
break
end
holder = holder..","
index = index + 1
end
return holder.."}"
end
if you want change the name just search all compileTable change it to you preferred name because this function will call it self if it detect nested table but escape sequence I don't know if it work
if you use this to create a lua executable file that output the table it will ge compilation error if you put new line and " sequence
this method is more memory efficient
Note:
Function not supported
User data I don't know
My solution:
local nl = string.char(10) -- newline
function serialize_list (tabl, indent)
indent = indent and (indent.." ") or ""
local str = ''
str = str .. indent.."{"
for key, value in pairs (tabl) do
local pr = (type(key)=="string") and ('["'..key..'"]=') or ""
if type (value) == "table" then
str = str..nl..pr..serialize_list (value, indent)..','
elseif type (value) == "string" then
str = str..nl..indent..pr..'"'..tostring(value)..'",'
else
str = str..nl..indent..pr..tostring(value)..','
end
end
str = str:sub(1, #str-1) -- remove last symbol
str = str..nl..indent.."}"
return str
end
local str = serialize_list(tables)
print('return '..nl..str)