| /* ISO7816-3 Fi/Di tables + computation */ |
| /* (C) 2010-2015 by Harald Welte <hwelte@hmw-consulting.de> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program 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 this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| */ |
| |
| #include <stdint.h> |
| #include <errno.h> |
| |
| #include "utils.h" |
| #include "iso7816_fidi.h" |
| |
| /* Table 7 of ISO 7816-3:2006 */ |
| const uint16_t fi_table[] = { |
| 372, 372, 558, 744, 1116, 1488, 1860, 0, |
| 0, 512, 768, 1024, 1536, 2048, 0, 0 |
| }; |
| |
| /* Table 8 from ISO 7816-3:2006 */ |
| const uint8_t di_table[] = { |
| 0, 1, 2, 4, 8, 16, 32, 64, |
| 12, 20, 2, 4, 8, 16, 32, 64, |
| }; |
| |
| /* compute the F/D ratio based on Fi and Di values */ |
| int compute_fidi_ratio(uint8_t fi, uint8_t di) |
| { |
| uint16_t f, d; |
| int ret; |
| |
| if (fi >= ARRAY_SIZE(fi_table) || |
| di >= ARRAY_SIZE(di_table)) |
| return -EINVAL; |
| |
| f = fi_table[fi]; |
| if (f == 0) |
| return -EINVAL; |
| |
| d = di_table[di]; |
| if (d == 0) |
| return -EINVAL; |
| |
| /* See table 7 of ISO 7816-3: From 1000 on we divide by 1/d, |
| * which equals a multiplication by d */ |
| if (di < 8) |
| ret = f / d; |
| else |
| ret = f * d; |
| |
| return ret; |
| } |