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7f5ec526fe
Lua 5.3 adds several awesome features of particular interest to nmap including bitwise operators and integers, a utf8 library, and standard binary pack/unpack functions. In addition to adding Lua 5.3, this branch changes: o Complete removal of the NSE bit library (in C), It has been replaced with a new Lua library wrapping Lua 5.3's bit-wise operators. o Complete removal of the NSE bin library (in C). It has been replaced with a new Lua library wrapping Lua 5.3's string.pack|unpack functions. o The bin.pack "B" format specifier (which has never worked correctly) is unimplemented. All scripts/libraries which use it have been updated. Most usage of this option was to allow string based bit-wise operations which are no longer necessary now that Lua 5.3 provides integers and bit-wise operators. o The base32/base64 libraries have been reimplemented using Lua 5.3's new bitwise operators. (This library was the main user of the bin.pack "B" format specifier.) o A new "bits" library has been added for common bit hacks. Currently only has a reverse function. Thanks to David Fifield, Daniel Miller, Jacek Wielemborek, and Paulino Calderon for testing this branch.
67 lines
1.8 KiB
Lua
67 lines
1.8 KiB
Lua
---
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-- Bit manipulation library.
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--
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-- @author Patrick Donnelly <batrick@batbytes.com>
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-- @copyright Same as Nmap -- see https://nmap.org/book/man-legal.html
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-- @see https://www.lua.org/manual/5.3/manual.html#3.4.2
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local assert = assert
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local error = error
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local _ENV = {}
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--- Reverses bits in integer.
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--
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-- @param n The integer.
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-- @param size The bit width of the integer (default: 8).
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-- @return The reversed integer.
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function reverse (n, size)
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if not size or size == 8 then
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n = n & 0xff
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n = (n & 0xf0) >> 4 | (n & 0x0f) << 4
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n = (n & 0xcc) >> 2 | (n & 0x33) << 2
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n = (n & 0xaa) >> 1 | (n & 0x55) << 1
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n = n & 0xff
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elseif size == 32 then
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n = n & 0xffffffff
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n = ((n >> 1) & 0x55555555) | ((n & 0x55555555) << 1);
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n = ((n >> 2) & 0x33333333) | ((n & 0x33333333) << 2);
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n = ((n >> 4) & 0x0F0F0F0F) | ((n & 0x0F0F0F0F) << 4);
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n = ((n >> 8) & 0x00FF00FF) | ((n & 0x00FF00FF) << 8);
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n = ( n >> 16 ) | ( n << 16);
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n = n & 0xffffffff
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else
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error("invalid size: "..size)
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end
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return n
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end
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do
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local function test8 (a, b)
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local r = reverse(a, 8)
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if r ~= b then
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error(("0x%02X: expected 0x%02X, got 0x%02X"):format(a, b, r))
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end
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end
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test8(0x00, 0x00)
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test8(0x01, 0x80)
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test8(0x80, 0x01)
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test8(0xff, 0xff)
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test8(0x88, 0x11)
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test8(0x5c, 0x3a)
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local function test32 (a, b)
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local r = reverse(a, 32)
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if r ~= b then
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error(("0x%08X: expected 0x%08X, got 0x%08X"):format(a, b, r))
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end
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end
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test32(0x00000000, 0x00000000)
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test32(0x00000001, 0x80000000)
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test32(0x80000000, 0x00000001)
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test32(0xffffffff, 0xffffffff)
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test32(0x22221234, 0x2c484444)
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end
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return _ENV
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