bapi

local crypt

for i,v in pairs(peripheral.getNames()) do
    if peripheral.getType(v) == "modem" then
        rednet.open(v)
    elseif peripheral.getType(v) == "cryptographic accelerator" then
        crypt = peripheral.wrap(v)
    end
end

local d

local pub, priv
local bkey
local akey

if fs.exists(".akey") then
    local file = fs.open(".akey", "r")
    akey = crypt.decodeKey("AES", file.readLine())
    bkey = crypt.decodeKey("RSA", file.readLine())
    pub = crypt.decodeKey("RSA", file.readLine())
    priv = crypt.decodeKey("RSA", file.readLine())
    file.close()
else
    pub, priv = crypt.generateKeyPair("RSA", 1024)
end

local function rMsg(enc)
    local time = os.startTimer(1)
    while true do
        local e, p1, p2, p3 = os.pullEvent()
        if e == "rednet_message" then
            if p1 == d and p3 == "luabank" then
                if enc == true then
                    return akey.decrypt("AES/CFB/NoPadding", p2)
                else
                    return p2
                end
            end
        elseif e == "timer" and p1 == time then
            return nil
        end
    end
end

local function sMsg(msg)
    rednet.send(d, "smsgs" .. akey.encrypt("AES/CFB/NoPadding", msg), "luabank")
end

function connect()
    d = rednet.lookup("luabank", "database")
    if not d then
        return false
    elseif not bkey then
        rednet.send(d, "skeys" .. pub.encode(), "luabank")
        local msg = rMsg()
        if msg and msg:sub(1, 5) == "mkeys" then
            local tub = msg:sub(6)
            bkey = crypt.decodeKey("RSA", tub)

            rednet.send(d, "tkeys" .. bkey.encrypt("RSA", "start"), "luabank")
            local dut = rMsg()
            if not dut then
                return false
            end
            if dut:sub(1, 5) == "ykeys" then
                akey = crypt.decodeKey("AES", dut:sub(6))
                local file = fs.open(".akey", "w")
                file.writeLine(dut:sub(6))
                file.writeLine(tub)
                file.writeLine(pub.encode())
                file.writeLine(priv.encode())
                file.close()
            else
                return false
            end
        else
            return false
        end
        return true
    else
        return true
    end
end

function register(user, pass)
    sMsg(textutils.serialize({"r", user, pass}))
    local dat = rMsg(true)
    if not dat then
        return false, "No response"
    elseif dat:sub(1, 5) == "error" then
        return false, dat:sub(6)
    else
        return dat
    end
end

function newcard(user, pass)
    sMsg(textutils.serialize({"c", user, pass}))
    local dat = rMsg(true)
    if not dat then
        return false, "No response"
    elseif dat:sub(1, 5) == "error" then
        return false, dat:sub(6)
    else
        return dat
    end
end

function transact(card, user, amount)
    sMsg(textutils.serialize({"t", card, user, amount}))
    local dat = rMsg(true)
    if not dat then
        return false, "No response"
    elseif dat:sub(1, 5) == "error" then
        return false, dat:sub(6)
    else
        return dat
    end
end

function transactu(user, pass, rec, amount)
    sMsg(textutils.serialize({"tu", user, pass, rec, amount}))
    local dat = rMsg(true)
    if not dat then
        return false, "No response"
    elseif dat:sub(1, 5) == "error" then
        return false, dat:sub(6)
    else
        return dat
    end
end

function transactl(user, pass, rec, amount)
    sMsg(textutils.serialize({"tl", user, pass, rec, amount}))
    local dat = rMsg(true)
    if not dat then
        return false, "No response"
    elseif dat:sub(1, 5) == "error" then
        return false, dat:sub(6)
    else
        return dat
    end
end