Modul:SHA2
Pendokumenan untuk modul ini boleh diciptakan di Modul:SHA2/doc
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