1 files changed, 245 insertions, 0 deletions
diff --git a/nselib/base32.lua b/nselib/base32.lua
new file mode 100644
index 0000000..e830ce1
--- /dev/null
+++ b/nselib/base32.lua
@@ -0,0 +1,245 @@
+-- The MIT License (MIT)
+-- Copyright (c) 2016 Patrick Joseph Donnelly (batrick@batbytes.com)
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy of
+-- this software and associated documentation files (the "Software"), to deal in
+-- the Software without restriction, including without limitation the rights to
+-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+-- of the Software, and to permit persons to whom the Software is furnished to do
+-- so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in all
+-- copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+-- SOFTWARE.
+
+---
+-- Base32 encoding and decoding. Follows RFC 4648.
+--
+-- @author Patrick Donnelly <batrick@batbytes.com>
+-- @copyright The MIT License (MIT); Copyright (c) 2016 Patrick Joseph Donnelly (batrick@batbytes.com)
+
+local assert = assert
+local error = error
+local ipairs = ipairs
+local setmetatable = setmetatable
+
+local open = require "io".open
+local popen = require "io".popen
+
+local random = require "math".random
+
+local tmpname = require "os".tmpname
+local remove = require "os".remove
+
+local char = require "string".char
+
+local concat = require "table".concat
+
+local unittest = require "unittest"
+
+_ENV = require "stdnse".module "base32"
+
+local b32standard = {
+  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+  'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+  'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+  'Y', 'Z', '2', '3', '4', '5', '6', '7',
+}
+
+local b32hexExtend = {
+  '0', '1', '2', '3', '4', '5', '6', '7',
+  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
+  'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
+  'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
+}
+
+local function etransform (t, a, b, c, d, e)
+    local e1 = t[((a>>3)&0x1f)+1]
+    local e2 = t[((((a<<2)&0x1c)|((b>>6)&0x03))&0x1f)+1]
+    local e3 = t[((b>>1)&0x1f)+1]
+    local e4 = t[((((b<<4)&0x10)|((c>>4)&0x0f))&0x1f)+1]
+    local e5 = t[((((c<<1)&0x1e)|((d>>7)&0x01))&0x1f)+1]
+    local e6 = t[((d>>2)&0x1f)+1]
+    local e7 = t[((((d<<3)&0x18)|((e>>5)&0x07))&0x1f)+1]
+    local e8 = t[(e&0x1f)+1]
+	return e1..e2..e3..e4..e5..e6..e7..e8
+end
+
+---
+-- Encodes a string to Base32.
+-- @param p Data to be encoded.
+-- @param hexExtend pass true to use the hex extended char set
+-- @return Base32-encoded string.
+function enc (p, hexExtend)
+    local b32table = not hexExtend and b32standard or b32hexExtend
+
+    local out = {}
+    local i = 1
+    local m = #p % 5
+
+    while i+(5-1) <= #p do
+        local a, b, c, d, e = p:byte(i, i+(5-1))
+        out[#out+1] = etransform(b32table, a, b, c, d, e)
+        i = i + 5
+    end
+
+	if m == 4 then
+        local a, b, c, d = p:byte(i, i+(4-1))
+        out[#out+1] = etransform(b32table, a, b, c, d, 0):sub(1, 7).."="
+	elseif m == 3 then
+        local a, b, c = p:byte(i, i+(3-1))
+        out[#out+1] = etransform(b32table, a, b, c, 0, 0):sub(1, 5).."==="
+	elseif m == 2 then
+        local a, b = p:byte(i, i+(2-1))
+        out[#out+1] = etransform(b32table, a, b, 0, 0, 0):sub(1, 4).."===="
+	elseif m == 1 then
+        local a = p:byte(i, i+(1-1))
+        out[#out+1] = etransform(b32table, a, 0, 0, 0, 0):sub(1, 2).."======"
+	end
+
+    return concat(out)
+end
+
+
+local db32metatable = {
+  __index = function (t, k) error "invalid encoding: invalid character" end
+}
+local db32table_standard = setmetatable({}, db32metatable)
+do
+    local r = {["="] = 0}
+    for i, v in ipairs(b32standard) do
+        r[v] = i-1
+    end
+    for i = 0, 255 do
+        db32table_standard[i] = r[char(i)]
+    end
+end
+local db32table_hex = setmetatable({}, db32metatable)
+do
+    local r = {["="] = 0}
+    for i, v in ipairs(b32hexExtend) do
+        r[v] = i-1
+    end
+    for i = 0, 255 do
+        db32table_hex[i] = r[char(i)]
+    end
+end
+
+
+-- Decodes Base32-encoded data.
+-- @param b32 Base32 encoded data.
+-- @param hexExtend pass true to use the hex extended char set
+-- @return Decoded data.
+function dec (b32, hexExtend)
+    local db32table = not hexExtend and db32table_standard or db32table_hex
+
+    local out = {}
+    local i = 1
+    local m = #b32 % 8
+    local done = false
+
+    if m ~= 0 then
+        error "invalid encoding: input is not divisible by 8"
+    end
+
+    while i+(8-1) <= #b32 do
+        if done then
+            error "invalid encoding: trailing characters"
+        end
+
+        local a, b, c, d, e, f, g, h = b32:byte(i, i+(8-1))
+
+        local v = ((db32table[a]<<3)&0xf8) | ((db32table[b]>>2)&0x07)
+        local w = ((db32table[b]<<6)&0xc0) | ((db32table[c]<<1)&0x3e) | ((db32table[d]>>4)&0x01)
+        local x = ((db32table[d]<<4)&0xf0) | ((db32table[e]>>1)&0x0f)
+        local y = ((db32table[e]<<7)&0x80) | ((db32table[f]<<2)&0x7c) | ((db32table[g]>>3)&0x03)
+        local z = ((db32table[g]<<5)&0xe0) | ((db32table[h]   )&0x1f)
+
+        if c == 0x3d then
+            assert(d == 0x3d and e == 0x3d and f == 0x3d and g == 0x3d and h == 0x3d, "invalid encoding: invalid character")
+            out[#out+1] = char(v)
+            done = true
+		elseif d == 0x3d then
+            error "invalid encoding: invalid character"
+        elseif e == 0x3d then
+            assert(f == 0x3d and g == 0x3d and h == 0x3d, "invalid encoding: invalid character")
+            out[#out+1] = char(v, w)
+            done = true
+        elseif f == 0x3d then
+            assert(g == 0x3d and h == 0x3d, "invalid encoding: invalid character")
+            out[#out+1] = char(v, w, x)
+            done = true
+        elseif g == 0x3d then
+            error "invalid encoding: invalid character"
+        elseif h == 0x3d then
+            out[#out+1] = char(v, w, x, y)
+            done = true
+        else
+            out[#out+1] = char(v, w, x, y, z)
+        end
+        i = i + 8
+    end
+
+    return concat(out)
+end
+
+if not unittest.testing() then
+  return _ENV
+end
+
+test_suite = unittest.TestSuite:new()
+
+local equal = unittest.equal
+local function test(a, b)
+  test_suite:add_test(equal(enc(a), b), "encoding")
+  test_suite:add_test(equal(dec(b), a), "decoding")
+end
+local function testh(a, b)
+  test_suite:add_test(equal(enc(a, true), b), "hex encoding")
+  test_suite:add_test(equal(dec(b, true), a), "hex decoding")
+end
+
+test("", "")
+test("f", "MY======")
+test("fo", "MZXQ====")
+test("foo", "MZXW6===")
+test("foob", "MZXW6YQ=")
+test("fooba", "MZXW6YTB")
+test("foobar", "MZXW6YTBOI======")
+testh("", "")
+testh("f", "CO======")
+testh("fo", "CPNG====")
+testh("foo", "CPNMU===")
+testh("foob", "CPNMUOG=")
+testh("foobar", "CPNMUOJ1E8======")
+
+-- extensive tests
+if false then
+  local path = tmpname()
+  local file = open(path, "w")
+  local t = {}
+  for a = 0, 255, random(1, 7) do
+    for b = 0, 255, random(2, 7) do
+      for c = 0, 255, random(2, 7) do
+        t[#t+1] = char(a, b, c, 0xA)
+        file:write(t[#t])
+      end
+    end
+  end
+  assert(file:close())
+  local input = concat(t)
+  local output = enc(input)
+  local good = assert(popen("base32 < "..path, "r")):read("a"):gsub("%s", "")
+  remove(path)
+  assert(output == good)
+  assert(dec(output) == input)
+end
+
+return _ENV