cvs.zerfleddert.de Git - proxmark3-svn/blob - armsrc/desfire_key.c

   1 /*-
   2  * Copyright (C) 2010, Romain Tartiere.
   3  *
   4  * This program is free software: you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License as published by the
   6  * Free Software Foundation, either version 3 of the License, or (at your
   7  * option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  16  *
  17  * $Id$
  18  */
  19
  20  #include "desfire_key.h"
  21
  22 static inline void update_key_schedules (desfirekey_t key);
  23
  24 static inline void update_key_schedules (desfirekey_t key) {
  25     // DES_set_key ((DES_cblock *)key->data, &(key->ks1));
  26     // DES_set_key ((DES_cblock *)(key->data + 8), &(key->ks2));
  27     // if (T_3K3DES == key->type) {
  28         // DES_set_key ((DES_cblock *)(key->data + 16), &(key->ks3));
  29     // }
  30 }
  31
  32 desfirekey_t Desfire_des_key_new (const uint8_t value[8]) {
  33     uint8_t data[8];
  34     memcpy (data, value, 8);
  35     for (int n=0; n < 8; n++)
  36         data[n] &= 0xfe;
  37     return Desfire_des_key_new_with_version (data);
  38 }
  39
  40 desfirekey_t Desfire_des_key_new_with_version (const uint8_t value[8]) {
  41     desfirekey_t key = NULL;
  42         key->type = T_DES;
  43         memcpy (key->data, value, 8);
  44         memcpy (key->data+8, value, 8);
  45         update_key_schedules (key);
  46     return key;
  47 }
  48
  49 desfirekey_t Desfire_3des_key_new (const uint8_t value[16]) {
  50     uint8_t data[16];
  51     memcpy (data, value, 16);
  52     for (int n=0; n < 8; n++)
  53         data[n] &= 0xfe;
  54     for (int n=8; n < 16; n++)
  55         data[n] |= 0x01;
  56     return Desfire_3des_key_new_with_version (data);
  57 }
  58
  59 desfirekey_t Desfire_3des_key_new_with_version (const uint8_t value[16]) {
  60     desfirekey_t key = NULL;
  61         key->type = T_3DES;
  62         memcpy (key->data, value, 16);
  63         update_key_schedules (key);
  64     return key;
  65 }
  66
  67 desfirekey_t Desfire_3k3des_key_new (const uint8_t value[24]) {
  68     uint8_t data[24];
  69     memcpy (data, value, 24);
  70     for (int n=0; n < 8; n++)
  71         data[n] &= 0xfe;
  72     return Desfire_3k3des_key_new_with_version (data);
  73 }
  74
  75 desfirekey_t Desfire_3k3des_key_new_with_version (const uint8_t value[24]) {
  76     desfirekey_t key = NULL;
  77     key->type = T_3K3DES;
  78     memcpy (key->data, value, 24);
  79     update_key_schedules (key);
  80     return key;
  81 }
  82
  83 desfirekey_t Desfire_aes_key_new (const uint8_t value[16]) {
  84     return Desfire_aes_key_new_with_version (value, 0);
  85 }
  86
  87 desfirekey_t Desfire_aes_key_new_with_version (const uint8_t value[16], uint8_t version) {
  88     desfirekey_t key = NULL;
  89         memcpy (key->data, value, 16);
  90         key->type = T_AES;
  91         key->aes_version = version;
  92     return key;
  93 }
  94
  95 uint8_t Desfire_key_get_version (desfirekey_t key) {
  96     uint8_t version = 0;
  97
  98     for (int n = 0; n < 8; n++) {
  99         version |= ((key->data[n] & 1) << (7 - n));
 100     }
 101
 102     return version;
 103 }
 104
 105 void Desfire_key_set_version (desfirekey_t key, uint8_t version)
 106 {
 107     for (int n = 0; n < 8; n++) {
 108         uint8_t version_bit = ((version & (1 << (7-n))) >> (7-n));
 109         key->data[n] &= 0xfe;
 110         key->data[n] |= version_bit;
 111         if (key->type == T_DES) {
 112             key->data[n+8] = key->data[n];
 113         } else {
 114             // Write ~version to avoid turning a 3DES key into a DES key
 115             key->data[n+8] &= 0xfe;
 116             key->data[n+8] |= ~version_bit;
 117         }
 118     }
 119 }
 120
 121 desfirekey_t Desfire_session_key_new (const uint8_t rnda[], const uint8_t rndb[], desfirekey_t authkey) {
 122
 123     desfirekey_t key = NULL;
 124
 125     uint8_t buffer[24];
 126
 127     switch (authkey->type) {
 128     case T_DES:
 129         memcpy (buffer, rnda, 4);
 130         memcpy (buffer+4, rndb, 4);
 131         key = Desfire_des_key_new_with_version (buffer);
 132         break;
 133     case T_3DES:
 134         memcpy (buffer, rnda, 4);
 135         memcpy (buffer+4, rndb, 4);
 136         memcpy (buffer+8, rnda+4, 4);
 137         memcpy (buffer+12, rndb+4, 4);
 138         key = Desfire_3des_key_new_with_version (buffer);
 139         break;
 140     case T_3K3DES:
 141         memcpy (buffer, rnda, 4);
 142         memcpy (buffer+4, rndb, 4);
 143         memcpy (buffer+8, rnda+6, 4);
 144         memcpy (buffer+12, rndb+6, 4);
 145         memcpy (buffer+16, rnda+12, 4);
 146         memcpy (buffer+20, rndb+12, 4);
 147         key = Desfire_3k3des_key_new (buffer);
 148         break;
 149     case T_AES:
 150         memcpy (buffer, rnda, 4);
 151         memcpy (buffer+4, rndb, 4);
 152         memcpy (buffer+8, rnda+12, 4);
 153         memcpy (buffer+12, rndb+12, 4);
 154         key = Desfire_aes_key_new (buffer);
 155         break;
 156     }
 157     return key;
 158 }