X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/c99dc845b1057be4ba2e535730345b4e6e8bfc58..ac4ecfe35327f827aeaf8426af2662c656affd2c:/armsrc/optimized_cipher.h diff --git a/armsrc/optimized_cipher.h b/armsrc/optimized_cipher.h index 0f4f0ec2..6a4e2641 100644 --- a/armsrc/optimized_cipher.h +++ b/armsrc/optimized_cipher.h @@ -1,5 +1,85 @@ -#ifndef OPTIMIZED_CIPHER_H +/***************************************************************************** + * 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, or, at your option, any later version. + * + * 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 . + * + * + ****************************************************************************/ + + #ifndef OPTIMIZED_CIPHER_H #define OPTIMIZED_CIPHER_H #include -void opt_doMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]); + +/** +* 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; + +/** The reader MAC is MAC(key, CC * NR ) + **/ +void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]); +/** + * The tag MAC is MAC(key, CC * NR * 32x0)) + */ +void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]); + +/** + * The tag MAC can be divided (both can, but no point in dividing the reader mac) into + * two functions, since the first 8 bytes are known, we can pre-calculate the state + * reached after feeding CC to the cipher. + * @param cc_p + * @param div_key_p + * @return the cipher state + */ +State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p); +/** + * The second part of the tag MAC calculation, since the CC is already calculated into the state, + * this function is fed only the NR, and internally feeds the remaining 32 0-bits to generate the tag + * MAC response. + * @param _init - precalculated cipher state + * @param nr - the reader challenge + * @param mac - where to store the MAC + * @param div_key_p - the key to use + */ +void opt_doTagMAC_2(State _init, uint8_t* nr, uint8_t mac[4], const uint8_t* div_key_p); + #endif // OPTIMIZED_CIPHER_H