ccryptolib/internal/maddq.lua
2022-03-04 12:31:51 -03:00

56 lines
1.2 KiB
Lua

local fq = require "ccryptolib.internal.fq"
local random = require "ccryptolib.random"
local function new(val, order)
local out = {}
local sum = fq.num(0)
for i = 1, order - 1 do
out[i] = fq.decodeWide(random.random(64))
sum = fq.add(sum, out[i])
end
out[order] = fq.add(val, fq.neg(sum))
return out
end
local function encode(arr)
local out = {}
for i = 1, #arr do out[i] = fq.encode(arr[i]) end
return table.concat(out)
end
local function decode(str)
local out = {}
for i = 1, #str / 32 do out[i] = fq.decode(str:sub(i * 32 - 31, i * 32)) end
return out
end
local function remask(arr)
local out = new(fq.num(0), #arr)
for i = 1, #arr do out[i] = fq.add(out[i], arr[i]) end
return out
end
local function reduce(arr, k)
local out = fq.num(0)
for i = 1, #arr do out = fq.add(out, fq.mul(arr[i], k)) end
return out
end
local function add(arr, v)
local out = {}
for i = 1, #arr do out[i] = fq.clone(arr[i]) end
out[#arr] = fq.add(out[#arr], v)
return out
end
return {
new = new,
encode = encode,
decode = decode,
remask = remask,
reduce = reduce,
add = add,
}