added abstraction layer to smart card connector

PC/SC can now be replaced by some arbitrary backend that communicates to
a smart card.

pcsc-relay/src/pcsc.c

@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2010 Frank Morgner
+ *
+ * This file is part of pcsc-relay.
+ *
+ * pcsc-relay 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.
+ *
+ * pcsc-relay 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
+ * pcsc-relay.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcsc-relay.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <winscard.h>
+
+#ifdef HAVE_PCSCLITE_H
+#include <pcsclite.h>
+#define stringify_error(r) pcsc_stringify_error(r)
+#else
+#define stringify_error(r) "PC/SC error code %u\n", (unsigned int) r
+#define SCARD_PROTOCOL_ANY (SCARD_PROTOCOL_T0|SCARD_PROTOCOL_T1)
+#endif
+
+#ifdef HAVE_READER_H
+#include <reader.h>
+#endif
+
+#define SHAREMODE SCARD_SHARE_EXCLUSIVE
+#define PREFERREDPROTOCOL SCARD_PROTOCOL_ANY
+
+
+struct pcsc_data {
+    LPSTR readers;
+    SCARDCONTEXT hContext;
+    SCARDHANDLE hCard;
+    DWORD dwActiveProtocol;
+};
+
+
+
+unsigned int readernum = -1;
+
+
+static int pcsc_connect(driver_data_t **driver_data)
+{
+    struct pcsc_data *data;
+
+    LONG r;
+    DWORD readerslen = SCARD_AUTOALLOCATE;
+    LPSTR readers = NULL;
+    char *reader;
+    size_t l, i;
+
+    if (!driver_data)
+        return 0;
+
+
+    data = realloc(*driver_data, sizeof *data);
+    if (!data)
+        return 0;
+    data->readers = NULL;
+    data->hContext = 0;
+    data->hCard = 0;
+    *driver_data = data;
+
+
+    r = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL, &data->hContext);
+    if (r != SCARD_S_SUCCESS) {
+        RELAY_ERROR("Could not connect to PC/SC Service\n");
+        goto err;
+    }
+
+
+    r = SCardListReaders(data->hContext, NULL, (LPSTR) &readers, &readerslen);
+    if (r != SCARD_S_SUCCESS) {
+        RELAY_ERROR("Could not get readers\n");
+        goto err;
+    }
+    data->readers = readers;
+
+    for (reader = readers, i = 0; readerslen > 0;
+            l = strlen(reader)+1, readerslen -= l, reader += l, i++) {
+
+        if (i == readernum)
+            break;
+    }
+    if (readerslen <= 0) {
+        RELAY_ERROR("Could not find reader number %u\n", readernum);
+        r = SCARD_E_UNKNOWN_READER;
+        goto err;
+    }
+
+
+    r = SCardConnect(data->hContext, reader, SHAREMODE, PREFERREDPROTOCOL,
+            &data->hCard, &data->dwActiveProtocol); 
+    if (r != SCARD_S_SUCCESS) {
+        RELAY_ERROR("Could not connect to %s\n", reader);
+        goto err;
+    }
+    INFO("Connected to %s\n", reader);
+
+err:
+    if (r != SCARD_S_SUCCESS) {
+        RELAY_ERROR("%s\n", stringify_error(r));
+        return 0;
+    }
+
+    return 1;
+}
+
+static int pcsc_disconnect(driver_data_t *driver_data)
+{
+    struct pcsc_data *data = driver_data;
+
+    if (data) {
+        SCardDisconnect(data->hCard, SCARD_LEAVE_CARD);
+        SCardFreeMemory(data->hContext, data->readers);
+        SCardReleaseContext(data->hContext);
+        free(data);
+    }
+
+    return 1;
+}
+
+static int pcsc_transmit(driver_data_t *driver_data,
+        const unsigned char *send, size_t send_len,
+        unsigned char *recv, size_t *recv_len)
+{
+    struct pcsc_data *data = driver_data;
+    LPCBYTE pbSendBuffer = send;
+    DWORD cbSendLength = send_len;
+    LPBYTE pbRecvBuffer = recv;
+    DWORD cbRecvLength = *recv_len;
+
+    LONG r;
+    SCARD_IO_REQUEST ioRecvPci;
+
+    switch (data->dwActiveProtocol) {
+        case SCARD_PROTOCOL_T0:
+            r = SCardTransmit(data->hCard, SCARD_PCI_T0, pbSendBuffer, cbSendLength,
+                    &ioRecvPci, pbRecvBuffer, &cbRecvLength);
+            break;
+
+        case SCARD_PROTOCOL_T1:
+            r = SCardTransmit(data->hCard, SCARD_PCI_T1, pbSendBuffer, cbSendLength,
+                    &ioRecvPci, pbRecvBuffer, &cbRecvLength);
+            break;
+
+        default:
+            RELAY_ERROR("Could not transmit with unknown protocol %u\n",
+                    (unsigned int) data->dwActiveProtocol);
+            r = SCARD_E_PROTO_MISMATCH;
+            break;
+    }
+
+    if (r != SCARD_S_SUCCESS) {
+        RELAY_ERROR("%s\n", stringify_error(r));
+        return 0;
+    }
+
+    *recv_len = cbRecvLength;
+
+    return 1;
+}
+
+
+struct sc_driver driver_pcsc = {
+    .connect = pcsc_connect,
+    .disconnect = pcsc_disconnect,
+    .transmit = pcsc_transmit,
+};