Module:SHA2

local bit32 = require("bit32")

-- http://lua-users.org/cgi-bin/wiki.pl?action=browse&id=SecureHashAlgorithm&revision=5 (MIT Licensed)

-- SHA-256 code in Lua 5.2; based on the pseudo-code from -- Wikipedia (http://en.wikipedia.org/wiki/SHA-2)

local band, rrotate, bxor, rshift, bnot = bit32.band, bit32.rrotate, bit32.bxor, bit32.rshift, bit32.bnot

local string, setmetatable, assert = string, setmetatable, assert

_ENV = nil

-- Initialize table of round constants -- (first 32 bits of the fractional parts of the cube roots of the first -- 64 primes 2..311): local k = { 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2, }

-- transform a string of bytes in a string of hexadecimal digits local function str2hexa (s) local h = string.gsub(s, ".", function(c)             return string.format("%02x", string.byte(c))            end) return h end

-- transform number 'l' in a big-endian sequence of 'n' bytes -- (coded as a string) local function num2s (l, n) local s = "" for i = 1, n do   local rem = l % 256 s = string.char(rem) .. s   l = (l - rem) / 256 end return s end

-- transform the big-endian sequence of four bytes starting at -- index 'i' in 's' into a number local function s232num (s, i) local n = 0 for i = i, i + 3 do   n = n*256 + string.byte(s, i)  end return n end

-- append the bit '1' to the message -- append k bits '0', where k is the minimum number >= 0 such that the -- resulting message length (in bits) is congruent to 448 (mod 512) -- append length of message (before pre-processing), in bits, as 64-bit -- big-endian integer local function preproc (msg, len) local extra = -(len + 1 + 8) % 64 len = num2s(8 * len, 8)   -- original len in bits, coded msg = msg .. "\128" .. string.rep("\0", extra) .. len assert(#msg % 64 == 0) return msg end

local function initH224 (H) -- (second 32 bits of the fractional parts of the square roots of the -- 9th through 16th primes 23..53) H[1] = 0xc1059ed8 H[2] = 0x367cd507 H[3] = 0x3070dd17 H[4] = 0xf70e5939 H[5] = 0xffc00b31 H[6] = 0x68581511 H[7] = 0x64f98fa7 H[8] = 0xbefa4fa4 return H end

local function initH256 (H) -- (first 32 bits of the fractional parts of the square roots of the -- first 8 primes 2..19): H[1] = 0x6a09e667 H[2] = 0xbb67ae85 H[3] = 0x3c6ef372 H[4] = 0xa54ff53a H[5] = 0x510e527f H[6] = 0x9b05688c H[7] = 0x1f83d9ab H[8] = 0x5be0cd19 return H end

local function digestblock (msg, i, H)

-- break chunk into sixteen 32-bit big-endian words w[1..16] local w = {} for j = 1, 16 do     w[j] = s232num(msg, i + (j - 1)*4) end

-- Extend the sixteen 32-bit words into sixty-four 32-bit words: for j = 17, 64 do     local v = w[j - 15] local s0 = bxor(rrotate(v, 7), rrotate(v, 18), rshift(v, 3)) v = w[j - 2] local s1 = bxor(rrotate(v, 17), rrotate(v, 19), rshift(v, 10)) w[j] = w[j - 16] + s0 + w[j - 7] + s1   end

-- Initialize hash value for this chunk: local a, b, c, d, e, f, g, h = H[1], H[2], H[3], H[4], H[5], H[6], H[7], H[8]

-- Main loop: for i = 1, 64 do     local s0 = bxor(rrotate(a, 2), rrotate(a, 13), rrotate(a, 22)) local maj = bxor(band(a, b), band(a, c), band(b, c)) local t2 = s0 + maj local s1 = bxor(rrotate(e, 6), rrotate(e, 11), rrotate(e, 25)) local ch = bxor (band(e, f), band(bnot(e), g)) local t1 = h + s1 + ch + k[i] + w[i]

h = g     g = f      f = e      e = d + t1      d = c      c = b      b = a      a = t1 + t2    end

-- Add (mod 2^32) this chunk's hash to result so far: H[1] = band(H[1] + a)   H[2] = band(H[2] + b)    H[3] = band(H[3] + c)    H[4] = band(H[4] + d)    H[5] = band(H[5] + e)    H[6] = band(H[6] + f)    H[7] = band(H[7] + g)    H[8] = band(H[8] + h)

end

local function finalresult224 (H) -- Produce the final hash value (big-endian): return str2hexa(num2s(H[1], 4)..num2s(H[2], 4)..num2s(H[3], 4)..num2s(H[4], 4)..            num2s(H[5], 4)..num2s(H[6], 4)..num2s(H[7], 4)) end

local function finalresult256 (H) -- Produce the final hash value (big-endian): return str2hexa(num2s(H[1], 4)..num2s(H[2], 4)..num2s(H[3], 4)..num2s(H[4], 4)..            num2s(H[5], 4)..num2s(H[6], 4)..num2s(H[7], 4)..num2s(H[8], 4)) end

-- local HH = {}   -- to reuse

local function hash224 (msg) msg = preproc(msg, #msg) local H = initH224(HH)

-- Process the message in successive 512-bit (64 bytes) chunks: for i = 1, #msg, 64 do   digestblock(msg, i, H)  end

return finalresult224(H) end

local function hash256 (msg) msg = preproc(msg, #msg) local H = initH256(HH)

-- Process the message in successive 512-bit (64 bytes) chunks: for i = 1, #msg, 64 do   digestblock(msg, i, H)  end

return finalresult256(H) end -- local mt = {}

local function new256 local o = {H = initH256({}), msg = "", len = 0} setmetatable(o, mt) return o end

mt.__index = mt

function mt:add (m) self.msg = self.msg .. m self.len = self.len + #m local t = 0 while #self.msg - t >= 64 do   digestblock(self.msg, t + 1, self.H)    t = t + 64 end self.msg = self.msg:sub(t + 1, -1) end

function mt:close self.msg = preproc(self.msg, self.len) self:add("") return finalresult256(self.H) end --

--return { -- hash224 = hash224, -- hash256 = hash256, -- new256 = new256, --}

local p = {}

function p.hash256(frame) return hash256(frame.args[1]) end

function p.hash224(frame) return hash224(frame.args[1]) end

return p