/* iso7816.c - ISO 7816 commands
* Copyright (C) 2003, 2004, 2008, 2009 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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 3 of the License, or
* (at your option) any later version.
*
* GnuPG 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, see .
*/
#include
#include
#include
#include
#include
#if defined(GNUPG_SCD_MAIN_HEADER)
#include GNUPG_SCD_MAIN_HEADER
#elif GNUPG_MAJOR_VERSION == 1
/* This is used with GnuPG version < 1.9. The code has been source
copied from the current GnuPG >= 1.9 and is maintained over
there. */
#include "options.h"
#include "errors.h"
#include "memory.h"
#include "util.h"
#include "i18n.h"
#else /* GNUPG_MAJOR_VERSION != 1 */
#include "scdaemon.h"
#endif /* GNUPG_MAJOR_VERSION != 1 */
#include "iso7816.h"
#include "apdu.h"
#define CMD_SELECT_FILE 0xA4
#define CMD_VERIFY ISO7816_VERIFY
#define CMD_CHANGE_REFERENCE_DATA ISO7816_CHANGE_REFERENCE_DATA
#define CMD_RESET_RETRY_COUNTER ISO7816_RESET_RETRY_COUNTER
#define CMD_GET_DATA 0xCA
#define CMD_PUT_DATA 0xDA
#define CMD_MSE 0x22
#define CMD_PSO 0x2A
#define CMD_INTERNAL_AUTHENTICATE 0x88
#define CMD_GENERATE_KEYPAIR 0x47
#define CMD_GET_CHALLENGE 0x84
#define CMD_READ_BINARY 0xB0
#define CMD_READ_RECORD 0xB2
static gpg_error_t
map_sw (int sw)
{
gpg_err_code_t ec;
switch (sw)
{
case SW_EEPROM_FAILURE: ec = GPG_ERR_HARDWARE; break;
case SW_TERM_STATE: ec = GPG_ERR_CARD; break;
case SW_WRONG_LENGTH: ec = GPG_ERR_INV_VALUE; break;
case SW_SM_NOT_SUP: ec = GPG_ERR_NOT_SUPPORTED; break;
case SW_CC_NOT_SUP: ec = GPG_ERR_NOT_SUPPORTED; break;
case SW_CHV_WRONG: ec = GPG_ERR_BAD_PIN; break;
case SW_CHV_BLOCKED: ec = GPG_ERR_PIN_BLOCKED; break;
case SW_USE_CONDITIONS: ec = GPG_ERR_USE_CONDITIONS; break;
case SW_NOT_SUPPORTED: ec = GPG_ERR_NOT_SUPPORTED; break;
case SW_BAD_PARAMETER: ec = GPG_ERR_INV_VALUE; break;
case SW_FILE_NOT_FOUND: ec = GPG_ERR_ENOENT; break;
case SW_RECORD_NOT_FOUND:ec= GPG_ERR_NOT_FOUND; break;
case SW_REF_NOT_FOUND: ec = GPG_ERR_NO_OBJ; break;
case SW_BAD_P0_P1: ec = GPG_ERR_INV_VALUE; break;
case SW_EXACT_LENGTH: ec = GPG_ERR_INV_VALUE; break;
case SW_INS_NOT_SUP: ec = GPG_ERR_CARD; break;
case SW_CLA_NOT_SUP: ec = GPG_ERR_CARD; break;
case SW_SUCCESS: ec = 0; break;
case SW_HOST_OUT_OF_CORE: ec = GPG_ERR_ENOMEM; break;
case SW_HOST_INV_VALUE: ec = GPG_ERR_INV_VALUE; break;
case SW_HOST_INCOMPLETE_CARD_RESPONSE: ec = GPG_ERR_CARD; break;
case SW_HOST_NOT_SUPPORTED: ec = GPG_ERR_NOT_SUPPORTED; break;
case SW_HOST_LOCKING_FAILED: ec = GPG_ERR_BUG; break;
case SW_HOST_BUSY: ec = GPG_ERR_EBUSY; break;
case SW_HOST_NO_CARD: ec = GPG_ERR_CARD_NOT_PRESENT; break;
case SW_HOST_CARD_INACTIVE: ec = GPG_ERR_CARD_RESET; break;
case SW_HOST_CARD_IO_ERROR: ec = GPG_ERR_EIO; break;
case SW_HOST_GENERAL_ERROR: ec = GPG_ERR_GENERAL; break;
case SW_HOST_NO_READER: ec = GPG_ERR_ENODEV; break;
case SW_HOST_ABORTED: ec = GPG_ERR_CANCELED; break;
case SW_HOST_NO_KEYPAD: ec = GPG_ERR_NOT_SUPPORTED; break;
default:
if ((sw & 0x010000))
ec = GPG_ERR_GENERAL; /* Should not happen. */
else if ((sw & 0xff00) == SW_MORE_DATA)
ec = 0; /* This should actually never been seen here. */
else
ec = GPG_ERR_CARD;
}
return gpg_error (ec);
}
/* Map a status word from the APDU layer to a gpg-error code. */
gpg_error_t
iso7816_map_sw (int sw)
{
/* All APDU functions should return 0x9000 on success but for
historical reasons of the implementation some return 0 to
indicate success. We allow for that here. */
return sw? map_sw (sw) : 0;
}
/* This function is specialized version of the SELECT FILE command.
SLOT is the card and reader as created for example by
apdu_open_reader (), AID is a buffer of size AIDLEN holding the
requested application ID. The function can't be used to enumerate
AIDs and won't return the AID on success. The return value is 0
for okay or a GPG error code. Note that ISO error codes are
internally mapped. Bit 0 of FLAGS should be set if the card does
not understand P2=0xC0. */
gpg_error_t
iso7816_select_application (int slot, const char *aid, size_t aidlen,
unsigned int flags)
{
int sw;
sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE, 4,
(flags&1)? 0 :0x0c, aidlen, aid);
return map_sw (sw);
}
gpg_error_t
iso7816_select_file (int slot, int tag, int is_dir,
unsigned char **result, size_t *resultlen)
{
int sw, p0, p1;
unsigned char tagbuf[2];
tagbuf[0] = (tag >> 8) & 0xff;
tagbuf[1] = tag & 0xff;
if (result || resultlen)
{
*result = NULL;
*resultlen = 0;
return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
}
else
{
p0 = (tag == 0x3F00)? 0: is_dir? 1:2;
p1 = 0x0c; /* No FC return. */
sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE,
p0, p1, 2, (char*)tagbuf );
return map_sw (sw);
}
return 0;
}
/* Do a select file command with a direct path. */
gpg_error_t
iso7816_select_path (int slot, const unsigned short *path, size_t pathlen,
unsigned char **result, size_t *resultlen)
{
int sw, p0, p1;
unsigned char buffer[100];
int buflen;
if (result || resultlen)
{
*result = NULL;
*resultlen = 0;
return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
}
if (pathlen/2 >= sizeof buffer)
return gpg_error (GPG_ERR_TOO_LARGE);
for (buflen = 0; pathlen; pathlen--, path++)
{
buffer[buflen++] = (*path >> 8);
buffer[buflen++] = *path;
}
p0 = 0x08;
p1 = 0x0c; /* No FC return. */
sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE,
p0, p1, buflen, (char*)buffer );
return map_sw (sw);
}
/* This is a private command currently only working for TCOS cards. */
gpg_error_t
iso7816_list_directory (int slot, int list_dirs,
unsigned char **result, size_t *resultlen)
{
int sw;
if (!result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
sw = apdu_send (slot, 0, 0x80, 0xAA, list_dirs? 1:2, 0, -1, NULL,
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
}
return map_sw (sw);
}
/* This funcion sends an already formatted APDU to the card. With
HANDLE_MORE set to true a MORE DATA status will be handled
internally. The return value is a gpg error code (i.e. a mapped
status word). This is basically the same as apdu_send_direct but
it maps the status word and does not return it in the result
buffer. */
gpg_error_t
iso7816_apdu_direct (int slot, const void *apdudata, size_t apdudatalen,
int handle_more,
unsigned char **result, size_t *resultlen)
{
int sw;
if (!result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
sw = apdu_send_direct (slot, 0, apdudata, apdudatalen, handle_more,
result, resultlen);
if (!sw)
{
if (*resultlen < 2)
sw = SW_HOST_GENERAL_ERROR;
else
{
sw = ((*result)[*resultlen-2] << 8) | (*result)[*resultlen-1];
(*resultlen)--;
(*resultlen)--;
}
}
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
}
return map_sw (sw);
}
/* Check whether the reader supports the ISO command code COMMAND on
the keypad. Returns 0 on success. */
gpg_error_t
iso7816_check_keypad (int slot, int command, pininfo_t *pininfo)
{
int sw;
sw = apdu_check_keypad (slot, command, pininfo);
return iso7816_map_sw (sw);
}
/* Perform a VERIFY command on SLOT using the card holder verification
vector CHVNO. With PININFO non-NULL the keypad of the reader will
be used. Returns 0 on success. */
gpg_error_t
iso7816_verify_kp (int slot, int chvno, pininfo_t *pininfo)
{
int sw;
sw = apdu_keypad_verify (slot, 0x00, CMD_VERIFY, 0, chvno, pininfo);
return map_sw (sw);
}
/* Perform a VERIFY command on SLOT using the card holder verification
vector CHVNO with a CHV of lenght CHVLEN. Returns 0 on success. */
gpg_error_t
iso7816_verify (int slot, int chvno, const char *chv, size_t chvlen)
{
int sw;
sw = apdu_send_simple (slot, 0, 0x00, CMD_VERIFY, 0, chvno, chvlen, chv);
return map_sw (sw);
}
/* Perform a CHANGE_REFERENCE_DATA command on SLOT for the card holder
verification vector CHVNO. With PININFO non-NULL the keypad of the
reader will be used. If IS_EXCHANGE is 0, a "change reference
data" is done, otherwise an "exchange reference data". */
gpg_error_t
iso7816_change_reference_data_kp (int slot, int chvno, int is_exchange,
pininfo_t *pininfo)
{
int sw;
sw = apdu_keypad_modify (slot, 0x00, CMD_CHANGE_REFERENCE_DATA,
is_exchange ? 1 : 0, chvno, pininfo);
return map_sw (sw);
}
/* Perform a CHANGE_REFERENCE_DATA command on SLOT for the card holder
verification vector CHVNO. If the OLDCHV is NULL (and OLDCHVLEN
0), a "change reference data" is done, otherwise an "exchange
reference data". The new reference data is expected in NEWCHV of
length NEWCHVLEN. */
gpg_error_t
iso7816_change_reference_data (int slot, int chvno,
const char *oldchv, size_t oldchvlen,
const char *newchv, size_t newchvlen)
{
int sw;
char *buf;
if ((!oldchv && oldchvlen)
|| (oldchv && !oldchvlen)
|| !newchv || !newchvlen )
return gpg_error (GPG_ERR_INV_VALUE);
buf = xtrymalloc (oldchvlen + newchvlen);
if (!buf)
return gpg_error (gpg_err_code_from_errno (errno));
if (oldchvlen)
memcpy (buf, oldchv, oldchvlen);
memcpy (buf+oldchvlen, newchv, newchvlen);
sw = apdu_send_simple (slot, 0, 0x00, CMD_CHANGE_REFERENCE_DATA,
oldchvlen? 0 : 1, chvno, oldchvlen+newchvlen, buf);
xfree (buf);
return map_sw (sw);
}
gpg_error_t
iso7816_reset_retry_counter_with_rc (int slot, int chvno,
const char *data, size_t datalen)
{
int sw;
if (!data || !datalen )
return gpg_error (GPG_ERR_INV_VALUE);
sw = apdu_send_simple (slot, 0, 0x00, CMD_RESET_RETRY_COUNTER,
0, chvno, datalen, data);
return map_sw (sw);
}
gpg_error_t
iso7816_reset_retry_counter (int slot, int chvno,
const char *newchv, size_t newchvlen)
{
int sw;
sw = apdu_send_simple (slot, 0, 0x00, CMD_RESET_RETRY_COUNTER,
2, chvno, newchvlen, newchv);
return map_sw (sw);
}
/* Perform a GET DATA command requesting TAG and storing the result in
a newly allocated buffer at the address passed by RESULT. Return
the length of this data at the address of RESULTLEN. */
gpg_error_t
iso7816_get_data (int slot, int extended_mode, int tag,
unsigned char **result, size_t *resultlen)
{
int sw;
int le;
if (!result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
if (extended_mode > 0 && extended_mode < 256)
le = 65534; /* Not 65535 in case it is used as some special flag. */
else if (extended_mode > 0)
le = extended_mode;
else
le = 256;
sw = apdu_send_le (slot, extended_mode, 0x00, CMD_GET_DATA,
((tag >> 8) & 0xff), (tag & 0xff), -1, NULL, le,
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
return 0;
}
/* Perform a PUT DATA command on card in SLOT. Write DATA of length
DATALEN to TAG. EXTENDED_MODE controls whether extended length
headers or command chaining is used instead of single length
bytes. */
gpg_error_t
iso7816_put_data (int slot, int extended_mode, int tag,
const void *data, size_t datalen)
{
int sw;
sw = apdu_send_simple (slot, extended_mode, 0x00, CMD_PUT_DATA,
((tag >> 8) & 0xff), (tag & 0xff),
datalen, (const char*)data);
return map_sw (sw);
}
/* Same as iso7816_put_data but uses an odd instruction byte. */
gpg_error_t
iso7816_put_data_odd (int slot, int extended_mode, int tag,
const void *data, size_t datalen)
{
int sw;
sw = apdu_send_simple (slot, extended_mode, 0x00, CMD_PUT_DATA+1,
((tag >> 8) & 0xff), (tag & 0xff),
datalen, (const char*)data);
return map_sw (sw);
}
/* Manage Security Environment. This is a weird operation and there
is no easy abstraction for it. Furthermore, some card seem to have
a different interpreation of 7816-8 and thus we resort to let the
caller decide what to do. */
gpg_error_t
iso7816_manage_security_env (int slot, int p1, int p2,
const unsigned char *data, size_t datalen)
{
int sw;
if (p1 < 0 || p1 > 255 || p2 < 0 || p2 > 255 )
return gpg_error (GPG_ERR_INV_VALUE);
sw = apdu_send_simple (slot, 0, 0x00, CMD_MSE, p1, p2,
data? datalen : -1, (const char*)data);
return map_sw (sw);
}
/* Perform the security operation COMPUTE DIGITAL SIGANTURE. On
success 0 is returned and the data is availavle in a newly
allocated buffer stored at RESULT with its length stored at
RESULTLEN. For LE see do_generate_keypair. */
gpg_error_t
iso7816_compute_ds (int slot, int extended_mode,
const unsigned char *data, size_t datalen, int le,
unsigned char **result, size_t *resultlen)
{
int sw;
if (!data || !datalen || !result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
if (!extended_mode)
le = 256; /* Ignore provided Le and use what apdu_send uses. */
else if (le >= 0 && le < 256)
le = 256;
sw = apdu_send_le (slot, extended_mode,
0x00, CMD_PSO, 0x9E, 0x9A,
datalen, (const char*)data,
le,
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
return 0;
}
/* Perform the security operation DECIPHER. PADIND is the padding
indicator to be used. It should be 0 if no padding is required, a
value of -1 suppresses the padding byte. On success 0 is returned
and the plaintext is available in a newly allocated buffer stored
at RESULT with its length stored at RESULTLEN. For LE see
do_generate_keypair. */
gpg_error_t
iso7816_decipher (int slot, int extended_mode,
const unsigned char *data, size_t datalen, int le,
int padind, unsigned char **result, size_t *resultlen)
{
int sw;
unsigned char *buf;
if (!data || !datalen || !result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
if (!extended_mode)
le = 256; /* Ignore provided Le and use what apdu_send uses. */
else if (le >= 0 && le < 256)
le = 256;
if (padind >= 0)
{
/* We need to prepend the padding indicator. */
buf = xtrymalloc (datalen + 1);
if (!buf)
return gpg_error (gpg_err_code_from_errno (errno));
*buf = padind; /* Padding indicator. */
memcpy (buf+1, data, datalen);
sw = apdu_send_le (slot, extended_mode,
0x00, CMD_PSO, 0x80, 0x86,
datalen+1, (char*)buf, le,
result, resultlen);
xfree (buf);
}
else
{
sw = apdu_send_le (slot, extended_mode,
0x00, CMD_PSO, 0x80, 0x86,
datalen, (const char *)data, le,
result, resultlen);
}
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
return 0;
}
/* For LE see do_generate_keypair. */
gpg_error_t
iso7816_internal_authenticate (int slot, int extended_mode,
const unsigned char *data, size_t datalen,
int le,
unsigned char **result, size_t *resultlen)
{
int sw;
if (!data || !datalen || !result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
if (!extended_mode)
le = 256; /* Ignore provided Le and use what apdu_send uses. */
else if (le >= 0 && le < 256)
le = 256;
sw = apdu_send_le (slot, extended_mode,
0x00, CMD_INTERNAL_AUTHENTICATE, 0, 0,
datalen, (const char*)data,
le,
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
return 0;
}
/* LE is the expected return length. This is usually 0 except if
extended length mode is used and more than 256 byte will be
returned. In that case a value of -1 uses a large default
(e.g. 4096 bytes), a value larger 256 used that value. */
static gpg_error_t
do_generate_keypair (int slot, int extended_mode, int read_only,
const unsigned char *data, size_t datalen,
int le,
unsigned char **result, size_t *resultlen)
{
int sw;
if (!data || !datalen || !result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
sw = apdu_send_le (slot, extended_mode,
0x00, CMD_GENERATE_KEYPAIR, read_only? 0x81:0x80, 0,
datalen, (const char*)data,
le >= 0 && le < 256? 256:le,
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
return 0;
}
gpg_error_t
iso7816_generate_keypair (int slot, int extended_mode,
const unsigned char *data, size_t datalen,
int le,
unsigned char **result, size_t *resultlen)
{
return do_generate_keypair (slot, extended_mode, 0,
data, datalen, le, result, resultlen);
}
gpg_error_t
iso7816_read_public_key (int slot, int extended_mode,
const unsigned char *data, size_t datalen,
int le,
unsigned char **result, size_t *resultlen)
{
return do_generate_keypair (slot, extended_mode, 1,
data, datalen, le, result, resultlen);
}
gpg_error_t
iso7816_get_challenge (int slot, int length, unsigned char *buffer)
{
int sw;
unsigned char *result;
size_t resultlen, n;
if (!buffer || length < 1)
return gpg_error (GPG_ERR_INV_VALUE);
do
{
result = NULL;
n = length > 254? 254 : length;
sw = apdu_send_le (slot, 0,
0x00, CMD_GET_CHALLENGE, 0, 0, -1, NULL, n,
&result, &resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
xfree (result);
return map_sw (sw);
}
if (resultlen > n)
resultlen = n;
memcpy (buffer, result, resultlen);
buffer += resultlen;
length -= resultlen;
xfree (result);
}
while (length > 0);
return 0;
}
/* Perform a READ BINARY command requesting a maximum of NMAX bytes
from OFFSET. With NMAX = 0 the entire file is read. The result is
stored in a newly allocated buffer at the address passed by RESULT.
Returns the length of this data at the address of RESULTLEN. */
gpg_error_t
iso7816_read_binary (int slot, size_t offset, size_t nmax,
unsigned char **result, size_t *resultlen)
{
int sw;
unsigned char *buffer;
size_t bufferlen;
int read_all = !nmax;
size_t n;
if (!result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
/* We can only encode 15 bits in p0,p1 to indicate an offset. Thus
we check for this limit. */
if (offset > 32767)
return gpg_error (GPG_ERR_INV_VALUE);
do
{
buffer = NULL;
bufferlen = 0;
n = read_all? 0 : nmax;
sw = apdu_send_le (slot, 0, 0x00, CMD_READ_BINARY,
((offset>>8) & 0xff), (offset & 0xff) , -1, NULL,
n, &buffer, &bufferlen);
if ( SW_EXACT_LENGTH_P(sw) )
{
n = (sw & 0x00ff);
sw = apdu_send_le (slot, 0, 0x00, CMD_READ_BINARY,
((offset>>8) & 0xff), (offset & 0xff) , -1, NULL,
n, &buffer, &bufferlen);
}
if (*result && sw == SW_BAD_P0_P1)
{
/* Bad Parameter means that the offset is outside of the
EF. When reading all data we take this as an indication
for EOF. */
break;
}
if (sw != SW_SUCCESS && sw != SW_EOF_REACHED)
{
/* Make sure that pending buffers are released. */
xfree (buffer);
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
if (*result) /* Need to extend the buffer. */
{
unsigned char *p = xtryrealloc (*result, *resultlen + bufferlen);
if (!p)
{
gpg_error_t err = gpg_error_from_syserror ();
xfree (buffer);
xfree (*result);
*result = NULL;
*resultlen = 0;
return err;
}
*result = p;
memcpy (*result + *resultlen, buffer, bufferlen);
*resultlen += bufferlen;
xfree (buffer);
buffer = NULL;
}
else /* Transfer the buffer into our result. */
{
*result = buffer;
*resultlen = bufferlen;
}
offset += bufferlen;
if (offset > 32767)
break; /* We simply truncate the result for too large
files. */
if (nmax > bufferlen)
nmax -= bufferlen;
else
nmax = 0;
}
while ((read_all && sw != SW_EOF_REACHED) || (!read_all && nmax));
return 0;
}
/* Perform a READ RECORD command. RECNO gives the record number to
read with 0 indicating the current record. RECCOUNT must be 1 (not
all cards support reading of more than one record). SHORT_EF
should be 0 to read the current EF or contain a short EF. The
result is stored in a newly allocated buffer at the address passed
by RESULT. Returns the length of this data at the address of
RESULTLEN. */
gpg_error_t
iso7816_read_record (int slot, int recno, int reccount, int short_ef,
unsigned char **result, size_t *resultlen)
{
int sw;
unsigned char *buffer;
size_t bufferlen;
if (!result || !resultlen)
return gpg_error (GPG_ERR_INV_VALUE);
*result = NULL;
*resultlen = 0;
/* We can only encode 15 bits in p0,p1 to indicate an offset. Thus
we check for this limit. */
if (recno < 0 || recno > 255 || reccount != 1
|| short_ef < 0 || short_ef > 254 )
return gpg_error (GPG_ERR_INV_VALUE);
buffer = NULL;
bufferlen = 0;
sw = apdu_send_le (slot, 0, 0x00, CMD_READ_RECORD,
recno,
short_ef? short_ef : 0x04,
-1, NULL,
0, &buffer, &bufferlen);
if (sw != SW_SUCCESS && sw != SW_EOF_REACHED)
{
/* Make sure that pending buffers are released. */
xfree (buffer);
xfree (*result);
*result = NULL;
*resultlen = 0;
return map_sw (sw);
}
*result = buffer;
*resultlen = bufferlen;
return 0;
}