lua实现xxTea加解密

不废话，贴代码：

function security.xxTEAEncrypt(str, key, toBase64)    toBase64 = toBase64 or true    if (str == "") then        return ""    end    local v = _str2long(str, true)    local k = _str2long(key, false)    if (#k < 4) then        for i = #k+1, 4, 1  do        k [i] = 0        end    end    local n = #v    local z = v [n]    local y = v [1]    local delta = -0x61C88647    local q = math.floor(6 + 52 / (n)) --设定加密轮数    local sum = 0    while 0 < q do        q = q -1        sum = _int32(sum + delta)        e = bit.band(bit.rshift(sum , 2), 3)        local p = 0        for p = 0, n-2 do        y = v [p + 2]            mx = bit.bxor(_int32(bit.bxor(bit.band(bit.rshift(z, 5), 0x07ffffff), bit.lshift(y , 2)) + bit.bxor(bit.band(bit.rshift(y, 3), 0x1fffffff), bit.lshift(z, 4))), _int32(bit.bxor(sum, y) + bit.bxor(k[bit.bxor(bit.band((p), 3), e)+1], z)))            z  = _int32(v[p+1] + mx)            v [p+1]  = z        end        p = #v - 1        y = v [1]        mx = bit.bxor(_int32(bit.bxor(bit.band(bit.rshift(z, 5), 0x07ffffff), bit.lshift(y , 2)) + bit.bxor(bit.band(bit.rshift(y, 3), 0x1fffffff), bit.lshift(z, 4))), _int32(bit.bxor(sum, y) + bit.bxor(k[bit.bxor(bit.band((p), 3), e)+1], z)))        z = _int32(v[n] + mx)        v [n] = z    end    if (toBase64) then        local r = security.url_safe_base64_encode(_long2str(v, false))        return r    end    return _long2str(v, false)endfunction security.xxTEADecrypt(str, key, toBase64)    toBase64 = toBase64 or true    if (str == "") then        return ""    end    -- logcat(str)    if toBase64 then        str = security.url_safe_base64_decode(str)    end    local v = _str2long(str, false)    local k = _str2long(key, false)    if (#k < 4) then        for i = #k+1, 4, 1  do            k [i] = 0        end    end    local n = #v - 1    local z = v [n]    local y = v [1]    local delta = -0x61C88647    local q = math.floor(6 + 52 / (n+1)) --设定加密轮数    local sum = _int32(q * delta)    while (sum ~= 0) do        e = bit.band(bit.rshift(sum , 2), 3)--         test_result = test_result .."e: "..e.."\n"--         logcat ("e: "..e)        local p = n         for p = n, 1, -1 do            z = v [p]--             test_result = test_result .."z: "..z.."p-1: "..(p-1).."\n"--             logcat ("z: "..z.."p-1: "..p-1)--             test_result = test_result .."y: "..y.."\n"--             logcat ("y: "..y)--             test_result = test_result .."p: "..p.."\n"--             logcat ("p: "..p)--             test_result = test_result .."k: "..(k[bit.bxor(bit.band((p), 3), e)+1]).."\n"--             logcat ("k: "..k[bit.bxor(bit.band((p), 3), e)+1])            mx = bit.bxor(_int32(bit.bxor(bit.band(bit.rshift(z, 5), 0x07ffffff), bit.lshift(y , 2)) + bit.bxor(bit.band(bit.rshift(y, 3), 0x1fffffff), bit.lshift(z, 4))), _int32(bit.bxor(sum, y) + bit.bxor(k[bit.bxor(bit.band((p), 3), e)+1], z)))--             test_result = test_result .."mx: "..mx.."\n"--             logcat ("mx: "..mx)            y  = _int32(v [p+1] - mx)--                         test_result = test_result .."y: "..y.."p: "..p.."\n"--             logcat ("y: "..y.."p: "..p)            v [p+1] = y        end<pre name="code" class="plain">function _long2str(v, w)    local len = #v    local n = bit.lshift((len - 1) , 2)    if (w) then        local m = v [len]        if ((m < n - 3) or (m > n)) then        return false        end        n = m    end    local s = {}    for i = 1 , len do        s [i] = string.packL(v[i])    end    if (w) then        return string.sub(table.concat(s, ''), 0, n)    else        return table.concat(s, '')    endendfunction _str2long(s, w)    local v = string.unpackL(s .. string.rep("\0", (4 - bit.band((string.len(s) % 4)  , 3))))    if (w) then        v [#v+1] = string.len(s)    end    return vendfunction _int32(n)    while (n >= 2147483649) do        n = n - 4294967296    end    while (n <= -2147483649) do        n = n + 4294967296    end    return nend

p = 0 z = v[n+1]-- test_result = test_result .."z2: "..z.."\n"-- logcat ("z2: "..z) mx = bit.bxor(_int32(bit.bxor(bit.band(bit.rshift(z, 5), 0x07ffffff), bit.lshift(y , 2)) + bit.bxor(bit.band(bit.rshift(y, 3), 0x1fffffff), bit.lshift(z, 4))), _int32(bit.bxor(sum, y) + bit.bxor(k[bit.bxor(bit.band((p), 3), e)+1], z)))-- test_result = test_result .."mx2: "..mx.."\n"-- logcat ("mx2: "..mx) y = _int32(v[1] - mx)-- test_result = test_result .."y2: "..y.."\n"-- logcat ("y2: "..y) v [1] = y sum = _int32(sum - delta) end return _long2str(v, true)end