Lua-hashings

Pure Lua cryptographic hash library.

Supported hashes

• adler32
• blake2b
• blake2s
• crc32
• md5
• ripemd160
• sha1
• sha256
• sha3_256
• sha3_512
• sha512
• whirlpool

Additional hash functions

• hmac
• pbkdf2

API

All hash modules support the same API and any module implementing this API can be used by the additional hash functions.

• new(data) or (data)
• copy()
• update(data)
• digest()
• hexdigest()

The digest and hexdigest functions will not change the internal state of the object. Multiple calls to these will return the same result.

All hash modules provide the following information about the hash.

• digest_size
• block_size

There are some functions, such as hexdigest, which are the same implementation in multiple modules. This is by design because modules are intended to be independent of the library itself. Each module can be copied into another project without needing the rest of the library. The hash functions are the same in that they can be dropped into another project and used independent of the library provided that anything using the hash functions implements the above API.

Dependencies

This library depends on lua-nums because many hashes rely on fixed width integers. It's also needed to support 64 bit hashes.

Example Use

LUA_PATH="../lua-nums/?/init.lua;../lua-nums/?.lua;../lua-hashings/?/init.lua;../lua-hashings/?.lua;./?.lua" lua hs.lua

local digest = require("hashings.sha256")
print(digest:new("Hello"):hexdigest())

local hashings = require("hashings")
local hs = hashings("sha256")
hs:update("Hello")
print(hs:hexdigest())

local mod = require("hashings").sha256
local hs = mod()
hs:update("Hello")
print(hs:hexdigest())

HMAC

local hashings = require("hashings")
local hs = hashings.hmac(hashings.sha256, 'secret123', "Hello")
print(hs:hexdigest())

local hashings = require("hashings")
local hs = hashings.hmac(hashings.sha256, 'secret123')
hs:update("Hello")
print(hs:hexdigest())

PBKDF2

local hashings = require("hashings")
print(hashings.pbkdf2(hashings.sha256, "password", 123, 256))

Data from file

local hs = require("hashings").sha256()
local f = io.open("hs.lua", "rb")
while true do
    local r = f:read(2) # You should use are more appropriately sized buffer
    if r == nuil then
        break
    end
    hs:update(r)
end
print(hs:hexdigest())

Performance

32 bit hashes have quite good performance. However, due to using lua-nums which provides fixed width unsigned 64 bit integers 64 bit hashes are very slow. It is not recommended to use 64 bit hashes in performance critical code.