diff options
author | Kévin Redon <kredon@sysmocom.de> | 2019-05-14 21:50:39 +0200 |
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committer | Harald Welte <laforge@osmocom.org> | 2021-04-04 21:02:10 +0200 |
commit | 4a29f64cbe12ca9fbddd66ae10b614388fef5e9b (patch) | |
tree | 5a4de929a1d927028536bfbcbf8f31ba590e9cf0 | |
parent | debbf3c6fa210ee75cef00e8c80f0286753d8d9a (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 | 70 | ||||
-rw-r--r-- | firmware/libcommon/source/iso7816_3.c | 159 |
2 files changed, 229 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..e6c1b4f --- /dev/null +++ b/firmware/libcommon/include/iso7816_3.h @@ -0,0 +1,70 @@ +/* + * 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. + * ISO/IEC 7816-3:2006(E) section 8.1 */ +#define ISO7816_3_DEFAULT_FD 372 + +/*! default baud rate adjustment factor Dd. + * ISO/IEC 7816-3:2006(E) section 8.1 */ +#define ISO7816_3_DEFAULT_DD 1 + +/*! default clock rate conversion integer Fi. + * 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. + * 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. + * 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. + * 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. + * 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 + +extern const uint16_t iso7816_3_fi_table[]; + +extern const uint32_t iso7816_3_fmax_table[]; + +extern const uint8_t iso7816_3_di_table[]; + +bool iso7816_3_valid_f(uint16_t f); + +bool iso7816_3_valid_d(uint8_t d); + +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..ccdff68 --- /dev/null +++ b/firmware/libcommon/source/iso7816_3.c @@ -0,0 +1,159 @@ +/* + * 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" + +/*! Table of clock rate conversion integer F indexed by Fi. + * \note Fi is indicated in TA1, but the same table is used for F and Fn during PPS + * ISO/IEC 7816-3:2006(E) table 7 */ +const uint16_t iso7816_3_fi_table[16] = { + 372, 372, 558, 744, 1116, 1488, 1860, 0, + 0, 512, 768, 1024, 1536, 2048, 0, 0 +}; + +/*! Table of maximum clock frequency f_max in Hz indexed by Fi. + * 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 */ +const uint32_t iso7816_3_fmax_table[16] = { + 4000000, 5000000, 6000000, 8000000, 12000000, 16000000, 20000000, 0, + 0, 5000000, 7500000, 10000000, 15000000, 20000000, 0, 0 +}; + +/*! Table encoding the baud rate adjust integer D indexed by Di. + * 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 */ +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) + */ + +/*! 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) +{ + 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); +} + +/*! 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) +{ + 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) + */ + +/*! Calculate Waiting Time (WT) in units of ETU. + * \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) + * 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) +{ + /* 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; + + /* see 7816-3 Section 10.2 */ + return wi * 960UL * (fi/f) * (di/d); // calculate timeout value in ETU +} |