local bit = bit or {}
local band = bit.band or bit32.band
local bnot = bit.bnot or bit32.bnot
local bxor = bit.bxor or bit32.bxor

local rrotate = bit.ror or bit32.rrotate
local rshift = bit.rshift or bit32.rshift

local primes =
{
    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,
}

local function toHex(str)
    local result = str:gsub('.', function (char)
        return string.format("%02x", char:byte())
    end)

    return result
end

local function toBytes(value, length)
    local str = ""

    for i = 1, length do
        local rem = value % 256
        str = string.char(rem) .. str
        value = (value - rem) / 256
    end

    return str
end

local function readInt32(buffer, index)
    local value = 0

    for i = index, index + 3 do
        value = (value * 256) + string.byte(buffer, i)
    end

    return value
end

local function digestBlock(msg, i, hash)
    local digest = {}

    for j = 1, 16 do
        digest[j] = readInt32(msg, i + (j - 1) * 4)
    end

    for j = 17, 64 do
        local v = digest[j - 15]
        local s0 = bxor(rrotate(v, 7), rrotate(v, 18), rshift(v, 3))

        v = digest[j - 2]
        digest[j] = digest[j - 16] + s0 + digest[j - 7] + bxor(rrotate(v, 17), rrotate(v, 19), rshift(v, 10))
    end

    local a, b, c, d, e, f, g, h = unpack(hash)

    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 + primes[i] + digest[i]

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

    hash[1] = band(hash[1] + a)
    hash[2] = band(hash[2] + b)
    hash[3] = band(hash[3] + c)
    hash[4] = band(hash[4] + d)
    hash[5] = band(hash[5] + e)
    hash[6] = band(hash[6] + f)
    hash[7] = band(hash[7] + g)
    hash[8] = band(hash[8] + h)
end

local function sha256(msg)
    local hash =
    {
        0x6a09e667,
        0xbb67ae85,
        0x3c6ef372,
        0xa54ff53a,
        0x510e527f,
        0x9b05688c,
        0x1f83d9ab,
        0x5be0cd19,
    }

    for i = 1, #msg, 64 do
        digestBlock(msg, i, hash)
    end

    local result = ""

    for i = 1, 8 do
        local value = hash[i]
        result = result .. toBytes(value, 4)
    end

    return toHex(result)
end

local input = string.rep(".", 1024)

loadfile("profile.lua")()

local ts0 = os.clock()


io.write(string.format("\"sha256\", %.8f, 20\n", profile_it(20, function ()
    for i = 1, 1024 do
        sha256(input)
    end
end)))

local ts1 = os.clock()

local input = sha256(input)
if (input ~= "8adcaee60bb05a9964a1df12d2f007adcb8f3fa20ff7d1ecfde0a2ac301ff412") then
    print("sha256 failed\n")
    return
end

io.write(string.format("\t%.8f mb/sec\n",1.0/((ts1-ts0)/20)))




