mirror of
https://gitea.osmocom.org/sim-card/simtrace2.git
synced 2026-08-16 04:11:24 +03:00
Eric Wild
d55729cba7
iso7816_3_compute_fd_ratio() multiplied F by D for every d_index >= 8, presumably because the upper half of ISO 7816-3 Table 8 encodes 1/D. But 7816-3 2006 and 1997 differ! That assumption is only true for the range 1010..1111, which in the 2006 version is RFU. Indices 1000 and 1001 are Di = 12 and Di = 20, see iso7816_3_di_table[]. So right now Fi=372/Di=12 -> 372 * 12 = 4464 instead of 372 / 12 = 31. In the cemu value is rejected in emu_update_fidi() and the old baud rate is silently kept. In the sniffer update_fidi() programs US_FIDI as 4464 & 0x7ff = 368, which is garbage. Use F/D for indices 1..9 and keep the legacy 1/D reading only for the RFU range, where we cant really do anything useful anyway. Change-Id: I44d6451d8b04aea2b0db7291b06a812afe84e52f
64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
/* ISO7816-3 Fi/Di tables + computation
|
|
*
|
|
* (C) 2010-2015 by Harald Welte <laforge@gnumonks.org>
|
|
*
|
|
* 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.
|
|
*/
|
|
#include <stdint.h>
|
|
#include <errno.h>
|
|
|
|
#include "utils.h"
|
|
#include "iso7816_fidi.h"
|
|
|
|
/* Table 7 of ISO 7816-3:2006 */
|
|
const uint16_t iso7816_3_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 iso7816_3_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 iso7816_3_compute_fd_ratio(uint8_t f_index, uint8_t d_index)
|
|
{
|
|
uint16_t f, d;
|
|
int ret;
|
|
|
|
if (f_index >= ARRAY_SIZE(iso7816_3_fi_table) ||
|
|
d_index >= ARRAY_SIZE(iso7816_3_di_table))
|
|
return -EINVAL;
|
|
|
|
f = iso7816_3_fi_table[f_index];
|
|
if (f == 0)
|
|
return -EINVAL;
|
|
|
|
d = iso7816_3_di_table[d_index];
|
|
if (d == 0)
|
|
return -EINVAL;
|
|
|
|
/* DI defined in Table 8 of ISO/IEC 7816-3:2006
|
|
* has values 0001..1001 as div 1, 2, 4, 8, 16, 32, 64, 12, 20
|
|
* so indices 1..9 are all divisors and the ratio is F/D.
|
|
* But Indices 1010..1111 are RFU in the 2006 edition!
|
|
* 1997 used those for 1/2 .. 1/64, where dividing by 1/d equals multiplying by d.
|
|
* Keep that legacy interpretation for the RFU range only. */
|
|
if (d_index < 10)
|
|
ret = f / d;
|
|
else
|
|
ret = f * d;
|
|
|
|
return ret;
|
|
}
|