Added MAC calculations with dummy filler as input.

This commit is contained in:
Dom 2018-03-20 16:46:55 +00:00
commit f882a16aed

View file

@ -162,14 +162,68 @@ function commitPerso()
end
end
function calculateMAC(MAC_input)
-- Pad the input if it is not a multiple of 16 bytes (32 nibbles).
if(string.len(MAC_input) % 32 != 0) then
MAC_input = MAC_input .. "80"
end
while(string.len(MAC_input) % 32 != 0) do
MAC_input = MAC_input .. "0"
end
print("Padded MAC Input = " .. MAC_input .. ", length = " .. string.len(MAC_input))
--The MAC would actually be calculated here, and the output stored in raw_output
raw_output = "00010203040506070001020304050607" -- Dummy filler for now of 16-byte output. To be filled with actual MAC for testing purposes.
-- The final 8-byte MAC output is a concatenation of every 2nd byte starting from the second MSB.
final_output = ""
j = 3
for i = 1,8 do
final_output = final_output .. string.sub(RndR, j, j + 1) .. string.sub(RndC, j, j + 1)
j = j + 4
end
return final_output
end
function proximityCheck()
commandString = PREPAREPC
response = sendRaw(commandString, true, true)
OPT = string.sub(response, 5, 6)
if(tonumber(OPT) == 1) then
pps_present = true
else
pps_present = false
end
pubRespTime = string.sub(response, 7, 10)
if(pps_present == true) then
pps = string.sub(response, 11, 12)
else
pps = nil
end
print("OPT = " .. OPT .. " pubRespTime = " .. pubRespTime .. " pps = " .. pps)
commandString = PROXIMITYCHECK .. "08" .. "0001020304050607"
RndC = "0001020304050607" --Random Challenge
commandString = PROXIMITYCHECK .. "08" .. RndC
response = sendRaw(commandString, true, true)
RndR = string.sub(response, 3, 18)
print("RndC = " .. RndC .. " RndR = " .. RndR)
commandString = VERIFYPC
MAC_input = "FD" .. OPT .. pubRespTime
if(pps_present == true) then
MAC_input = MAC_input .. pps
end
concat = ""
j = 1
for i = 1,8 do
concat = concat .. string.sub(RndR, j, j + 1) .. string.sub(RndC, j, j + 1)
j = j + 2
end
MAC_input = MAC_input .. concat
print("concat = " .. concat .. " MAC_input = " .. MAC_input)
MAC_tag = calculateMAC(MAC_input)
print(MAC_tag)
end