What’s the reason, that I get different results from an online SHA-256 calculator HASH-code and the code generated by the Lua script I’ve pasted?
Answer online: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Answer script (with SciTE): a006267b0042805304ec162a0070030510452429204488c160351215ac00c19
--
-- Adaptation of the Secure Hashing Algorithm (SHA-244/256)
-- Found Here: http://lua-users.org/wiki/SecureHashAlgorithm
--
-- Using an adapted version of the bit library
-- Found Here: https://bitbucket.org/Boolsheet/bslf/src/1ee664885805/bit.lua
--
-- Adapted into a single function by GravityScore
--
local function sha256(msg)
local function band(int1, int2, int3, ...)
local ret =
((int1%0x00000002>=0x00000001 and int2%0x00000002>=0x00000001 and 0x00000001) or 0)+
((int1%0x00000004>=0x00000002 and int2%0x00000004>=0x00000002 and 0x00000002) or 0)+
((int1%0x00000008>=0x00000004 and int2%0x00000008>=0x00000004 and 0x00000004) or 0)+
((int1%0x00000010>=0x00000008 and int2%0x00000010>=0x00000008 and 0x00000008) or 0)+
((int1%0x00000020>=0x00000010 and int2%0x00000020>=0x00000010 and 0x00000010) or 0)+
((int1%0x00000040>=0x00000020 and int2%0x00000040>=0x00000020 and 0x00000020) or 0)+
((int1%0x00000080>=0x00000040 and int2%0x00000080>=0x00000040 and 0x00000040) or 0)+
((int1%0x00000100>=0x00000080 and int2%0x00000100>=0x00000080 and 0x00000080) or 0)+
((int1%0x00000200>=0x00000100 and int2%0x00000200>=0x00000100 and 0x00000100) or 0)+
((int1%0x00000400>=0x00000200 and int2%0x00000400>=0x00000200 and 0x00000200) or 0)+
((int1%0x00000800>=0x00000400 and int2%0x00000800>=0x00000400 and 0x00000400) or 0)+
((int1%0x00001000>=0x00000800 and int2%0x00001000>=0x00000800 and 0x00000800) or 0)+
((int1%0x00002000>=0x00001000 and int2%0x00002000>=0x00001000 and 0x00001000) or 0)+
((int1%0x00004000>=0x00002000 and int2%0x00004000>=0x00002000 and 0x00002000) or 0)+
((int1%0x00008000>=0x00004000 and int2%0x00008000>=0x00004000 and 0x00004000) or 0)+
((int1%0x00010000>=0x00008000 and int2%0x00010000>=0x00008000 and 0x00008000) or 0)+
((int1%0x00020000>=0x00010000 and int2%0x00020000>=0x00010000 and 0x00010000) or 0)+
((int1%0x00040000>=0x00020000 and int2%0x00040000>=0x00020000 and 0x00020000) or 0)+
((int1%0x00080000>=0x00040000 and int2%0x00080000>=0x00040000 and 0x00040000) or 0)+
((int1%0x00100000>=0x00080000 and int2%0x00100000>=0x00080000 and 0x00080000) or 0)+
((int1%0x00200000>=0x00100000 and int2%0x00200000>=0x00100000 and 0x00100000) or 0)+
((int1%0x00400000>=0x00200000 and int2%0x00400000>=0x00200000 and 0x00200000) or 0)+
((int1%0x00800000>=0x00400000 and int2%0x00800000>=0x00400000 and 0x00400000) or 0)+
((int1%0x01000000>=0x00800000 and int2%0x01000000>=0x00800000 and 0x00800000) or 0)+
((int1%0x02000000>=0x01000000 and int2%0x02000000>=0x01000000 and 0x01000000) or 0)+
((int1%0x04000000>=0x02000000 and int2%0x04000000>=0x02000000 and 0x02000000) or 0)+
((int1%0x08000000>=0x04000000 and int2%0x08000000>=0x04000000 and 0x04000000) or 0)+
((int1%0x10000000>=0x08000000 and int2%0x10000000>=0x08000000 and 0x08000000) or 0)+
((int1%0x20000000>=0x10000000 and int2%0x20000000>=0x10000000 and 0x10000000) or 0)+
((int1%0x40000000>=0x20000000 and int2%0x40000000>=0x20000000 and 0x20000000) or 0)+
((int1%0x80000000>=0x40000000 and int2%0x80000000>=0x40000000 and 0x40000000) or 0)+
((int1>=0x80000000 and int2>=0x80000000 and 0x80000000) or 0)
return (int3 and band(ret, int3, ...)) or ret
end
local function bxor(int1, int2, int3, ...)
local ret =
((int1%0x00000002>=0x00000001 ~= (int2%0x00000002>=0x00000001) and 0x00000001) or 0)+
((int1%0x00000004>=0x00000002 ~= (int2%0x00000004>=0x00000002) and 0x00000002) or 0)+
((int1%0x00000008>=0x00000004 ~= (int2%0x00000008>=0x00000004) and 0x00000004) or 0)+
((int1%0x00000010>=0x00000008 ~= (int2%0x00000010>=0x00000008) and 0x00000008) or 0)+
((int1%0x00000020>=0x00000010 ~= (int2%0x00000020>=0x00000010) and 0x00000010) or 0)+
((int1%0x00000040>=0x00000020 ~= (int2%0x00000040>=0x00000020) and 0x00000020) or 0)+
((int1%0x00000080>=0x00000040 ~= (int2%0x00000080>=0x00000040) and 0x00000040) or 0)+
((int1%0x00000100>=0x00000080 ~= (int2%0x00000100>=0x00000080) and 0x00000080) or 0)+
((int1%0x00000200>=0x00000100 ~= (int2%0x00000200>=0x00000100) and 0x00000100) or 0)+
((int1%0x00000400>=0x00000200 ~= (int2%0x00000400>=0x00000200) and 0x00000200) or 0)+
((int1%0x00000800>=0x00000400 ~= (int2%0x00000800>=0x00000400) and 0x00000400) or 0)+
((int1%0x00001000>=0x00000800 ~= (int2%0x00001000>=0x00000800) and 0x00000800) or 0)+
((int1%0x00002000>=0x00001000 ~= (int2%0x00002000>=0x00001000) and 0x00001000) or 0)+
((int1%0x00004000>=0x00002000 ~= (int2%0x00004000>=0x00002000) and 0x00002000) or 0)+
((int1%0x00008000>=0x00004000 ~= (int2%0x00008000>=0x00004000) and 0x00004000) or 0)+
((int1%0x00010000>=0x00008000 ~= (int2%0x00010000>=0x00008000) and 0x00008000) or 0)+
((int1%0x00020000>=0x00010000 ~= (int2%0x00020000>=0x00010000) and 0x00010000) or 0)+
((int1%0x00040000>=0x00020000 ~= (int2%0x00040000>=0x00020000) and 0x00020000) or 0)+
((int1%0x00080000>=0x00040000 ~= (int2%0x00080000>=0x00040000) and 0x00040000) or 0)+
((int1%0x00100000>=0x00080000 ~= (int2%0x00100000>=0x00080000) and 0x00080000) or 0)+
((int1%0x00200000>=0x00100000 ~= (int2%0x00200000>=0x00100000) and 0x00100000) or 0)+
((int1%0x00400000>=0x00200000 ~= (int2%0x00400000>=0x00200000) and 0x00200000) or 0)+
((int1%0x00800000>=0x00400000 ~= (int2%0x00800000>=0x00400000) and 0x00400000) or 0)+
((int1%0x01000000>=0x00800000 ~= (int2%0x01000000>=0x00800000) and 0x00800000) or 0)+
((int1%0x02000000>=0x01000000 ~= (int2%0x02000000>=0x01000000) and 0x01000000) or 0)+
((int1%0x04000000>=0x02000000 ~= (int2%0x04000000>=0x02000000) and 0x02000000) or 0)+
((int1%0x08000000>=0x04000000 ~= (int2%0x08000000>=0x04000000) and 0x04000000) or 0)+
((int1%0x10000000>=0x08000000 ~= (int2%0x10000000>=0x08000000) and 0x08000000) or 0)+
((int1%0x20000000>=0x10000000 ~= (int2%0x20000000>=0x10000000) and 0x10000000) or 0)+
((int1%0x40000000>=0x20000000 ~= (int2%0x40000000>=0x20000000) and 0x20000000) or 0)+
((int1%0x80000000>=0x40000000 ~= (int2%0x80000000>=0x40000000) and 0x40000000) or 0)+
((int1>=0x80000000 ~= (int2>=0x80000000) and 0x80000000) or 0)
return (int3 and bxor(ret, int3, ...)) or ret
end
local function bnot(int)
return 4294967295 - int
end
local function rshift(int, by)
local shifted = int / (2 ^ by)
return shifted - shifted % 1
end
local function rrotate(int, by)
local shifted = int / (2 ^ by)
local fraction = shifted % 1
return (shifted - fraction) + fraction * (2 ^ 32)
end
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,
}
local function str2hexa(s)
local h = string.gsub(s, ".", function(c)
return string.format("%02x", string.byte(c))
end)
return h
end
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
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
local function preproc(msg, len)
local extra = 64 - ((len + 1 + 8) % 64)
len = num2s(8 * len, 8)
msg = msg .. "\128" .. string.rep("\0", extra) .. len
return msg
end
local function initH256(H)
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)
local w = {}
for j = 1, 16 do w[j] = s232num(msg, i + (j - 1) * 4) end
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
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]
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, f, e, d, c, b, a = g, f, e, d + t1, c, b, a, t1 + t2
end
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
msg = preproc(msg, #msg)
local H = initH256({})
for i = 1, #msg, 64 do digestblock(msg, i, H) end
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
test = sha256("abc");
print(test);
There are two major bugs in your code.
The reference Lua 5.2 algorithm at http://lua-users.org/wiki/SecureHashAlgorithm, from which this code is adapted, gives correct answers.
First, the functions
band,rrotateandrshiftdo not work properly because they expect unsigned integers and they sometimes receive negative values. To fix that, add a line telling something likeint = int % 2^32at the start of all those functions to ensure the numbers are between 0 and 4294967295.There is a second problem. Compared to the reference implementation, the ending lines in the form of
H[1] = band(H[1] + a)have been transformed intoH[1] = band(H[1], a). This is not the same thing! Replace them with something likeH[1] = (H[1] + a) % 2^32and now the function gives correct answers.