X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/b19caaefc277335ed623e0a3b6c80be31fce439c..10a8875c723002d015b8f8872f1d50759f090c89:/armsrc/cipher.c diff --git a/armsrc/cipher.c b/armsrc/cipher.c deleted file mode 100644 index 7c9cc873..00000000 --- a/armsrc/cipher.c +++ /dev/null @@ -1,272 +0,0 @@ -/***************************************************************************** - * WARNING - * - * THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY. - * - * USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL - * PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL, - * AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES. - * - * THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS. - * - ***************************************************************************** - * - * This file is part of loclass. It is a reconstructon of the cipher engine - * used in iClass, and RFID techology. - * - * The implementation is based on the work performed by - * Flavio D. Garcia, Gerhard de Koning Gans, Roel Verdult and - * Milosch Meriac in the paper "Dismantling IClass". - * - * Copyright (C) 2014 Martin Holst Swende - * - * This is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as published - * by the Free Software Foundation. - * - * This file is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with loclass. If not, see . - * - * - * - ****************************************************************************/ - - -#include "cipher.h" -#include "cipherutils.h" -#include -#include -#include -#include -#ifndef ON_DEVICE -#include "fileutils.h" -#endif - - -/** -* Definition 1 (Cipher state). A cipher state of iClass s is an element of F 40/2 -* consisting of the following four components: -* 1. the left register l = (l 0 . . . l 7 ) ∈ F 8/2 ; -* 2. the right register r = (r 0 . . . r 7 ) ∈ F 8/2 ; -* 3. the top register t = (t 0 . . . t 15 ) ∈ F 16/2 . -* 4. the bottom register b = (b 0 . . . b 7 ) ∈ F 8/2 . -**/ -typedef struct { - uint8_t l; - uint8_t r; - uint8_t b; - uint16_t t; -} State; - -/** -* Definition 2. The feedback function for the top register T : F 16/2 → F 2 -* is defined as -* T (x 0 x 1 . . . . . . x 15 ) = x 0 ⊕ x 1 ⊕ x 5 ⊕ x 7 ⊕ x 10 ⊕ x 11 ⊕ x 14 ⊕ x 15 . -**/ -bool T(State state) -{ - bool x0 = state.t & 0x8000; - bool x1 = state.t & 0x4000; - bool x5 = state.t & 0x0400; - bool x7 = state.t & 0x0100; - bool x10 = state.t & 0x0020; - bool x11 = state.t & 0x0010; - bool x14 = state.t & 0x0002; - bool x15 = state.t & 0x0001; - return x0 ^ x1 ^ x5 ^ x7 ^ x10 ^ x11 ^ x14 ^ x15; -} -/** -* Similarly, the feedback function for the bottom register B : F 8/2 → F 2 is defined as -* B(x 0 x 1 . . . x 7 ) = x 1 ⊕ x 2 ⊕ x 3 ⊕ x 7 . -**/ -bool B(State state) -{ - bool x1 = state.b & 0x40; - bool x2 = state.b & 0x20; - bool x3 = state.b & 0x10; - bool x7 = state.b & 0x01; - - return x1 ^ x2 ^ x3 ^ x7; - -} - - -/** -* Definition 3 (Selection function). The selection function select : F 2 × F 2 × -* F 8/2 → F 3/2 is defined as select(x, y, r) = z 0 z 1 z 2 where -* z 0 = (r 0 ∧ r 2 ) ⊕ (r 1 ∧ r 3 ) ⊕ (r 2 ∨ r 4 ) -* z 1 = (r 0 ∨ r 2 ) ⊕ (r 5 ∨ r 7 ) ⊕ r 1 ⊕ r 6 ⊕ x ⊕ y -* z 2 = (r 3 ∧ r 5 ) ⊕ (r 4 ∧ r 6 ) ⊕ r 7 ⊕ x -**/ -uint8_t _select(bool x, bool y, uint8_t r) -{ - bool r0 = r >> 7 & 0x1; - bool r1 = r >> 6 & 0x1; - bool r2 = r >> 5 & 0x1; - bool r3 = r >> 4 & 0x1; - bool r4 = r >> 3 & 0x1; - bool r5 = r >> 2 & 0x1; - bool r6 = r >> 1 & 0x1; - bool r7 = r & 0x1; - - bool z0 = (r0 & r2) ^ (r1 & ~r3) ^ (r2 | r4); - bool z1 = (r0 | r2) ^ ( r5 | r7) ^ r1 ^ r6 ^ x ^ y; - bool z2 = (r3 & ~r5) ^ (r4 & r6 ) ^ r7 ^ x; - - // The three bitz z0.. z1 are packed into a uint8_t: - // 00000ZZZ - //Return value is a uint8_t - uint8_t retval = 0; - retval |= (z0 << 2) & 4; - retval |= (z1 << 1) & 2; - retval |= z2 & 1; - - // Return value 0 <= retval <= 7 - return retval; -} - -/** -* Definition 4 (Successor state). Let s = l, r, t, b be a cipher state, k ∈ (F 82 ) 8 -* be a key and y ∈ F 2 be the input bit. Then, the successor cipher state s ′ = -* l ′ , r ′ , t ′ , b ′ is defined as -* t ′ := (T (t) ⊕ r 0 ⊕ r 4 )t 0 . . . t 14 l ′ := (k [select(T (t),y,r)] ⊕ b ′ ) ⊞ l ⊞ r -* b ′ := (B(b) ⊕ r 7 )b 0 . . . b 6 r ′ := (k [select(T (t),y,r)] ⊕ b ′ ) ⊞ l -* -* @param s - state -* @param k - array containing 8 bytes -**/ -State successor(uint8_t* k, State s, bool y) -{ - bool r0 = s.r >> 7 & 0x1; - bool r4 = s.r >> 3 & 0x1; - bool r7 = s.r & 0x1; - - State successor = {0,0,0,0}; - - successor.t = s.t >> 1; - successor.t |= (T(s) ^ r0 ^ r4) << 15; - - successor.b = s.b >> 1; - successor.b |= (B(s) ^ r7) << 7; - - bool Tt = T(s); - - successor.l = ((k[_select(Tt,y,s.r)] ^ successor.b) + s.l+s.r ) & 0xFF; - successor.r = ((k[_select(Tt,y,s.r)] ^ successor.b) + s.l ) & 0xFF; - - return successor; -} -/** -* We define the successor function suc which takes a key k ∈ (F 82 ) 8 , a state s and -* an input y ∈ F 2 and outputs the successor state s ′ . We overload the function suc -* to multiple bit input x ∈ F n 2 which we define as -* @param k - array containing 8 bytes -**/ -State suc(uint8_t* k,State s, BitstreamIn *bitstream) -{ - if(bitsLeft(bitstream) == 0) - { - return s; - } - bool lastbit = tailBit(bitstream); - return successor(k,suc(k,s,bitstream), lastbit); -} - -/** -* Definition 5 (Output). Define the function output which takes an internal -* state s =< l, r, t, b > and returns the bit r 5 . We also define the function output -* on multiple bits input which takes a key k, a state s and an input x ∈ F n 2 as -* output(k, s, ǫ) = ǫ -* output(k, s, x 0 . . . x n ) = output(s) · output(k, s ′ , x 1 . . . x n ) -* where s ′ = suc(k, s, x 0 ). -**/ -void output(uint8_t* k,State s, BitstreamIn* in, BitstreamOut* out) -{ - if(bitsLeft(in) == 0) - { - return; - } - pushBit(out,(s.r >> 2) & 1); - //Remove first bit - uint8_t x0 = headBit(in); - State ss = successor(k,s,x0); - output(k,ss,in, out); -} - -/** -* Definition 6 (Initial state). Define the function init which takes as input a -* key k ∈ (F 82 ) 8 and outputs the initial cipher state s =< l, r, t, b > -**/ - -State init(uint8_t* k) -{ - State s = { - ((k[0] ^ 0x4c) + 0xEC) & 0xFF,// l - ((k[0] ^ 0x4c) + 0x21) & 0xFF,// r - 0x4c, // b - 0xE012 // t - }; - return s; -} -void MAC(uint8_t* k, BitstreamIn input, BitstreamOut out) -{ - uint8_t zeroes_32[] = {0,0,0,0}; - BitstreamIn input_32_zeroes = {zeroes_32,sizeof(zeroes_32)*8,0}; - State initState = suc(k,init(k),&input); - output(k,initState,&input_32_zeroes,&out); -} - -void doMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]) -{ - uint8_t cc_nr[13] = { 0 }; - uint8_t div_key[8]; - //cc_nr=(uint8_t*)malloc(length+1); - - memcpy(cc_nr,cc_nr_p,12); - memcpy(div_key,div_key_p,8); - - reverse_arraybytes(cc_nr,12); - BitstreamIn bitstream = {cc_nr,12 * 8,0}; - uint8_t dest []= {0,0,0,0,0,0,0,0}; - BitstreamOut out = { dest, sizeof(dest)*8, 0 }; - MAC(div_key,bitstream, out); - //The output MAC must also be reversed - reverse_arraybytes(dest, sizeof(dest)); - memcpy(mac, dest, 4); - //free(cc_nr); - return; -} -#ifndef ON_DEVICE -int testMAC() -{ - prnlog("[+] Testing MAC calculation..."); - - //From the "dismantling.IClass" paper: - uint8_t cc_nr[] = {0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0,0,0,0}; - //From the paper - uint8_t div_key[8] = {0xE0,0x33,0xCA,0x41,0x9A,0xEE,0x43,0xF9}; - uint8_t correct_MAC[4] = {0x1d,0x49,0xC9,0xDA}; - - uint8_t calculated_mac[4] = {0}; - doMAC(cc_nr,div_key, calculated_mac); - - if(memcmp(calculated_mac, correct_MAC,4) == 0) - { - prnlog("[+] MAC calculation OK!"); - - }else - { - prnlog("[+] FAILED: MAC calculation failed:"); - printarr(" Calculated_MAC", calculated_mac, 4); - printarr(" Correct_MAC ", correct_MAC, 4); - return 1; - } - - return 0; -} -#endif