diff options
author | Kévin Redon <kredon@sysmocom.de> | 2019-05-14 21:50:39 +0200 |
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committer | Eric Wild <ewild@sysmocom.de> | 2020-03-26 02:23:26 +0100 |
commit | 656fda7ddda4dabe067cf043b06b6bdb18ad8a1f (patch) | |
tree | 0c6516cc4f07b1baa35fc0d7b0dd9f488acf25d9 | |
parent | 4a76fe50ea0d42db8526fa3be37fadd508b9461f (diff) |
add library providing ISO 7816-3 utilities
this will become part of libosmocore since it it common to smart
card related projects (such as osmo-ccid-firmware)
Change-Id: I3d4c65d137fc4555fcb256443feadd1c695de73d
-rw-r--r-- | firmware/libcommon/include/iso7816_3.h | 98 | ||||
-rw-r--r-- | firmware/libcommon/source/iso7816_3.c | 123 |
2 files changed, 221 insertions, 0 deletions
diff --git a/firmware/libcommon/include/iso7816_3.h b/firmware/libcommon/include/iso7816_3.h new file mode 100644 index 0000000..738d2a2 --- /dev/null +++ b/firmware/libcommon/include/iso7816_3.h @@ -0,0 +1,98 @@ +/* + * Copyright (C) 2019 sysmocom -s.f.m.c. GmbH, Author: Kevin Redon <kredon@sysmocom.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +*/ +/* this library provides utilities to handle the ISO-7816 part 3 communication aspects (e.g. related to F and D) */ +#pragma once + +#include <stdint.h> +#include <stdbool.h> + +/** default clock rate conversion integer Fd + * @implements ISO/IEC 7816-3:2006(E) section 8.1 + */ +#define ISO7816_3_DEFAULT_FD 372 +/** default baud rate adjustment factor Dd + * @implements ISO/IEC 7816-3:2006(E) section 8.1 + */ +#define ISO7816_3_DEFAULT_DD 1 +/** default clock rate conversion integer Fi + * @implements ISO/IEC 7816-3:2006(E) section 8.3 + * @note non-default value is optionally specified in TA1 + */ +#define ISO7816_3_DEFAULT_FI 372 +/** default baud rate adjustment factor Di + * @implements ISO/IEC 7816-3:2006(E) section 8.3 + * @note non-default value is optionally specified in TA1 + */ +#define ISO7816_3_DEFAULT_DI 1 +/** default maximum clock frequency, in Hz + * @implements ISO/IEC 7816-3:2006(E) section 8.3 + * @note non-default value is optionally specified in TA1 + */ +#define ISO7816_3_DEFAULT_FMAX 5000000UL +/** default Waiting Integer (WI) value for T=0 + * @implements ISO/IEC 7816-3:2006(E) section 10.2 + * @note non-default value is optionally specified in TC2 + */ +#define ISO7816_3_DEFAULT_WI 10 +/** default Waiting Time (WT) value, in ETU + * @implements ISO/IEC 7816-3:2006(E) section 8.1 + * @note depends on Fi, Di, and WI if protocol T=0 is selected + */ +#define ISO7816_3_DEFAULT_WT 9600 + +/** Table encoding the clock rate conversion integer Fi + * @note Fi is indicated in TA1, but the same table is used for F and Fn during PPS + * @implements ISO/IEC 7816-3:2006(E) table 7 + */ +extern const uint16_t iso7816_3_fi_table[]; + +/** Table encoding the maximum clock frequency f_max in Hz + * @implements ISO/IEC 7816-3:2006(E) table 7 + * @note f_max is indicated in TA1, but the same table is used for F and Fn during PPS + */ +extern const uint32_t iso7816_3_fmax_table[]; + +/** Table encoding the baud rate adjust integer Di + * @implements ISO/IEC 7816-3:2006(E) table 8 + * @note Di is indicated in TA1, but the same table is used for D and Dn during PPS + */ +extern const uint8_t iso7816_3_di_table[]; + +/* verify if the clock rate conversion integer F value is valid + * @param[in] f F value to be validated + * @return if F value is valid + * @note only values in ISO/IEC 7816-3:2006(E) table 7 are valid + */ +bool iso7816_3_valid_f(uint16_t f); +/* verify if the baud rate adjustment factor D value is valid + * @param[in] d D value to be validated + * @return if D value is valid + * @note only values in ISO/IEC 7816-3:2006(E) table 8 are valid + */ +bool iso7816_3_valid_d(uint8_t d); +/** calculate Waiting Time (WT) + * @param[in] wi Waiting Integer + * @param[in] fi clock rate conversion integer Fi value + * @param[in] di baud rate adjustment factor Di value + * @param[in] f clock rate conversion integer F value + * @param[in] d baud rate adjustment factor D value + * @return Waiting Time WT, in ETU, or < 0 on error (see code for return codes) + * @note this should happen after reset and T=0 protocol select (through PPS or implicit) + * @implements ISO/IEC 7816-3:2006(E) section 8.1 and 10.2 + */ +int32_t iso7816_3_calculate_wt(uint8_t wi, uint16_t fi, uint8_t di, uint16_t f, uint8_t d); diff --git a/firmware/libcommon/source/iso7816_3.c b/firmware/libcommon/source/iso7816_3.c new file mode 100644 index 0000000..f7262fb --- /dev/null +++ b/firmware/libcommon/source/iso7816_3.c @@ -0,0 +1,123 @@ +/* + * Copyright (C) 2019 sysmocom -s.f.m.c. GmbH, Author: Kevin Redon <kredon@sysmocom.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +*/ +#include <stdint.h> +#include <stddef.h> + +#include "utils.h" +#include "iso7816_3.h" + +const uint16_t iso7816_3_fi_table[16] = { + 372, 372, 558, 744, 1116, 1488, 1860, 0, + 0, 512, 768, 1024, 1536, 2048, 0, 0 +}; + +const uint32_t iso7816_3_fmax_table[16] = { + 4000000, 5000000, 6000000, 8000000, 12000000, 16000000, 20000000, 0, + 0, 5000000, 7500000, 10000000, 15000000, 20000000, 0, 0 +}; + +const uint8_t iso7816_3_di_table[16] = { + 0, 1, 2, 4, 8, 16, 32, 64, + 12, 20, 0, 0, 0, 0, 0, 0, +}; + +/* all values are based on the Elementary Time Unit (ETU), defined in ISO/IEC 7816-3 section 7.1 + * this is the time required to transmit a bit, and is calculated as follows: 1 ETU = (F / D) x (1 / f) where: + * - F is the clock rate conversion integer + * - D is the baud rate adjustment factor + * - f is the clock frequency + * the possible F, f(max), and D values are defined in ISO/IEC 7816-3 table 7 and 8 + * - the initial value for F (after reset) is Fd = 372 + * - the initial value for D (after reset) is Dd = 1 + * - the initial maximum frequency f(max) is 5 MHz + * the card must measure the ETU based on the clock signal provided by the reader + * one ETU (e.g. 1 bit) takes F/D clock cycles, which the card must count + * + * the card can indicate an alternative set of supported values Fi (with corresponding f(max)) and Di for higher baud rate in TA1 in the ATR (see ISO/IEC 7816-3 section 8.3) + * these values are selected according to ISO/IEC 7816-3 section 6.3.1: + * - card in specific mode: they are enforced if TA2 is present (the reader can deactivate the card if it does not support these values) + * - card in negotiable mode: + * -- they can be selected by the reader using the Protocol and Parameters Selection (PPS) procedure + * -- the first offered protocol and default values are used when no PPS is started + * + * PPS is done with Fd and Dd (see ISO/IEC 7816-3 section 9) + * the reader can propose any F and D values between from Fd to Fi, and from Dd to Di (Fi and Di are indicated in TA1) + * the in PPS agreed values F and D are called Fn and Dn and are applied after a successful exchange, corresponding to PPS1_Response bit 5 + * + * the F and D values must be provided to the SAM3S USART peripheral (after reset and PPS) + */ + +bool iso7816_3_valid_f(uint16_t f) +{ + if (0 == f) { + return false; + } + uint8_t i = 0; + for (i = 0; i < ARRAY_SIZE(iso7816_3_fi_table) && iso7816_3_fi_table[i] != f; i++); + return (i < ARRAY_SIZE(iso7816_3_fi_table) && iso7816_3_fi_table[i] == f); +} + +bool iso7816_3_valid_d(uint8_t d) +{ + if (0 == d) { + return false; + } + uint8_t i = 0; + for (i = 0; i < ARRAY_SIZE(iso7816_3_di_table) && iso7816_3_di_table[i] != d; i++); + return (i < ARRAY_SIZE(iso7816_3_di_table) && iso7816_3_di_table[i] == d); +} + +/* + * the ETU is not only used to define the baud rate, but also the Waiting Time (WT) (see ISO/IEC 7816-3 section 8.1) + * when exceeding WT without card response, the reader flags the card as unresponsive, and resets it + * this can be used by the card to indicate errors or unsupported operations + * if the card requires more time to respond, it shall send a procedure byte to restart WT + * WT is calculated as follows (for T=0, see ISO/IEC 7816-3 section 10.2): WT = WI x 960 x (Fi / f(max)) where + * - WI is encoded in TC2 in the ATR (10 if absent) + * - WI does not depend on D/Di (used for the ETU) + * - after reset WT is 9600 ETU + * - WI (e.g. the new WT) is applied when T=0 is used (after 6.3.1), even if Fi is not Fn (this WT extension is important to know for the reader so to have the right timeout) + */ + +int32_t iso7816_3_calculate_wt(uint8_t wi, uint16_t fi, uint8_t di, uint16_t f, uint8_t d) +{ + // sanity checks + if (0 == wi) { + return -1; + } + if (!iso7816_3_valid_f(fi)) { + return -2; + } + if (!iso7816_3_valid_d(di)) { + return -3; + } + if (!iso7816_3_valid_f(f)) { + return -4; + } + if (!iso7816_3_valid_d(d)) { + return -5; + } + if (f > fi) { + return -6; + } + if (d > di) { + return -7; + } + + return wi * 960UL * (fi/f) * (di/d); // calculate timeout value in ETU +} |