From Lua 5.3 docs: "Despite the name, the metamethod for this event can
be either a function or a table. [...] If it is a table, the final
result is the result of indexing this table with key."
Every place this function is used, the result is padded with 0s anyway,
so may as well not strip them here. Didn't remove the padding code since
this could return only 4 chars, and most padding is to 8-char width.
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.
Unnecessary, probably, but this eliminates 2 of 7 string
creations/collections due to concatenation and reassignment. Also
eliminates 2 unneeded table lookups and tests (since host always has
host.ip and port always has port.number), and eliminates 1 extra test
for prerule and postrule scripts, since we can't have a port if we don't
have a host.
The charset argument was intended to be a table, since Lua doesn't allow
indexing strings with []. Unfortunately, irc-brute and tftp-enum passed
a string instead, which meant that the output was always the empty
string. This change allows both formats, and fixes those scripts.
irc-brute and tftp-enum had been broken since r33632 (no released
version of Nmap)
This allows stdnse.keys to be used in a __pairs metamethod to, for
instance, yield keys in sorted order. Using next() bypasses the __pairs
metamethod that would be called when pairs() was used. Otherwise,
infinite recursion was possible.
Mostly splitting function summaries (the first paragraph of NSEdoc) from
the body of the description to make the summary indexes shorter and
easier to scan.
Also fixed some unbalanced code tags like <code>foo</table>
This allows usage of verbose/debug in portrule/hostrule and access to all
functionality of NSE, including sockets. So for example, we can now do:
function portrule (host, port)
local response = http.get(host, port, "/");
stdnse.debug1(response.body)
...
end
The verbose/debug function did not work in rule functions because the
introspection API (getid, gettid, etc.) only work when NSE is in the main loop.
The main loop sets the required internal variable current needed by the API.
List of changes:
stdnse.lua:
o debug/verbose check the debugging/verbosity level much earlier to allow
returning if nothing will be printed.
o Simplified debug/verbose logic to handle the optional first argument
better.
o made debug/verbose local functions to avoid using globals and allow self
tail calls
nse_main.lua:
o The logic for adding threads via a rule function is simplified. So long as
the script has the desired rule function, a thread is always returned.
Evaluation of the rule function is done while NSE is in the main loop (i.e.
not in script:new_thread()). The rule function only determines if the action
function is run.
o [Not a change:] If the action function will be run or was run then we see
the usual "Starting X" and "Finished X" messages from NSE.
o Use Lua 5.2's pack function instead of the slightly more expensive
{n = select("#", ...), ...} idiom.
o New stdnse.getinfo introspection function which is used by stdnse.debug.
1. The first paragraph of a function's NSEdoc is used as a short
summary. Some of these were very long, so I split off a shorter summary.
2. Use asterisks (*) to denote bulletted lists, not 'o'
3. Wrap lines at 80 columns
4. a couple other spelling and formatting fixes
