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-rw-r--r--scd/iso7816.c762
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diff --git a/scd/iso7816.c b/scd/iso7816.c
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+++ b/scd/iso7816.c
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+/* iso7816.c - ISO 7816 commands
+ * Copyright (C) 2003, 2004 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * $Id$
+ */
+
+#include <config.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#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_WRONG_LENGTH: ec = GPG_ERR_INV_VALUE; 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, 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, 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, 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, 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);
+}
+
+
+/* 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, iso7816_pininfo_t *pininfo)
+{
+ int sw;
+
+ sw = apdu_check_keypad (slot, command,
+ pininfo->mode, pininfo->minlen, pininfo->maxlen,
+ pininfo->padlen);
+ return map_sw (sw);
+}
+
+
+/* Perform a VERIFY command on SLOT using the card holder verification
+ vector CHVNO with a CHV of lenght CHVLEN. 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, const char *chv, size_t chvlen,
+ iso7816_pininfo_t *pininfo)
+{
+ int sw;
+
+ if (pininfo && pininfo->mode)
+ sw = apdu_send_simple_kp (slot, 0x00, CMD_VERIFY, 0, chvno, chvlen, chv,
+ pininfo->mode,
+ pininfo->minlen,
+ pininfo->maxlen,
+ pininfo->padlen);
+ else
+ sw = apdu_send_simple (slot, 0x00, CMD_VERIFY, 0, chvno, chvlen, chv);
+ 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)
+{
+ return iso7816_verify_kp (slot, chvno, chv, chvlen, NULL);
+}
+
+/* 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. With PININFO non-NULL the keypad of the reader
+ will be used. */
+gpg_error_t
+iso7816_change_reference_data_kp (int slot, int chvno,
+ const char *oldchv, size_t oldchvlen,
+ const char *newchv, size_t newchvlen,
+ iso7816_pininfo_t *pininfo)
+{
+ 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);
+
+ if (pininfo && pininfo->mode)
+ sw = apdu_send_simple_kp (slot, 0x00, CMD_CHANGE_REFERENCE_DATA,
+ oldchvlen? 0 : 1, chvno, oldchvlen+newchvlen, buf,
+ pininfo->mode,
+ pininfo->minlen,
+ pininfo->maxlen,
+ pininfo->padlen);
+ else
+ sw = apdu_send_simple (slot, 0x00, CMD_CHANGE_REFERENCE_DATA,
+ oldchvlen? 0 : 1, chvno, oldchvlen+newchvlen, buf);
+ xfree (buf);
+ 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)
+{
+ return iso7816_change_reference_data_kp (slot, chvno, oldchv, oldchvlen,
+ newchv, newchvlen, NULL);
+}
+
+
+gpg_error_t
+iso7816_reset_retry_counter_kp (int slot, int chvno,
+ const char *newchv, size_t newchvlen,
+ iso7816_pininfo_t *pininfo)
+{
+ int sw;
+
+ if (!newchv || !newchvlen )
+ return gpg_error (GPG_ERR_INV_VALUE);
+
+ if (pininfo && pininfo->mode)
+ sw = apdu_send_simple_kp (slot, 0x00, CMD_RESET_RETRY_COUNTER,
+ 2, chvno, newchvlen, newchv,
+ pininfo->mode,
+ pininfo->minlen,
+ pininfo->maxlen,
+ pininfo->padlen);
+ else
+ sw = apdu_send_simple (slot, 0x00, CMD_RESET_RETRY_COUNTER,
+ 2, chvno, newchvlen, newchv);
+ return map_sw (sw);
+}
+
+
+gpg_error_t
+iso7816_reset_retry_counter (int slot, int chvno,
+ const char *newchv, size_t newchvlen)
+{
+ return iso7816_reset_retry_counter_kp (slot, chvno, newchv, newchvlen, NULL);
+}
+
+
+
+/* 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 tag,
+ 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, 0x00, CMD_GET_DATA,
+ ((tag >> 8) & 0xff), (tag & 0xff), -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);
+ }
+
+ return 0;
+}
+
+
+/* Perform a PUT DATA command on card in SLOT. Write DATA of length
+ DATALEN to TAG. */
+gpg_error_t
+iso7816_put_data (int slot, int tag,
+ const unsigned char *data, size_t datalen)
+{
+ int sw;
+
+ sw = apdu_send_simple (slot, 0x00, CMD_PUT_DATA,
+ ((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, 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. */
+gpg_error_t
+iso7816_compute_ds (int slot, const unsigned char *data, size_t datalen,
+ 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 (slot, 0x00, CMD_PSO, 0x9E, 0x9A, datalen, (const char*)data,
+ 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. */
+gpg_error_t
+iso7816_decipher (int slot, const unsigned char *data, size_t datalen,
+ 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 (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 (slot, 0x00, CMD_PSO, 0x80, 0x86,
+ datalen+1, (char*)buf,
+ result, resultlen);
+ xfree (buf);
+ }
+ else
+ {
+ sw = apdu_send (slot, 0x00, CMD_PSO, 0x80, 0x86,
+ datalen, (const char *)data,
+ 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_internal_authenticate (int slot,
+ const unsigned char *data, size_t datalen,
+ 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 (slot, 0x00, CMD_INTERNAL_AUTHENTICATE, 0, 0,
+ datalen, (const char*)data, 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;
+}
+
+
+static gpg_error_t
+do_generate_keypair (int slot, int readonly,
+ const unsigned char *data, size_t datalen,
+ 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 (slot, 0x00, CMD_GENERATE_KEYPAIR, readonly? 0x81:0x80, 0,
+ datalen, (const char*)data, 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,
+ const unsigned char *data, size_t datalen,
+ unsigned char **result, size_t *resultlen)
+{
+ return do_generate_keypair (slot, 0, data, datalen, result, resultlen);
+}
+
+
+gpg_error_t
+iso7816_read_public_key (int slot,
+ const unsigned char *data, size_t datalen,
+ unsigned char **result, size_t *resultlen)
+{
+ return do_generate_keypair (slot, 1, data, datalen, 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, 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;
+ /* Note, that we to set N to 254 due to problems either with the
+ ccid driver or some TCOS cards. It actually should be 0
+ which is the official ISO value to read a variable length
+ object. */
+ if (read_all || nmax > 254)
+ n = 254;
+ else
+ n = nmax;
+ sw = apdu_send_le (slot, 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, 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_errno (errno);
+ 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;
+ /* Fixme: Either the ccid driver or the TCOS cards have problems
+ with an Le of 0. */
+ sw = apdu_send_le (slot, 0x00, CMD_READ_RECORD,
+ recno,
+ short_ef? short_ef : 0x04,
+ -1, NULL,
+ 254, &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;
+}
+