1 files changed, 394 insertions, 0 deletions
diff --git a/src/pcsc.c b/src/pcsc.c
new file mode 100644
index 0000000..d7bd6c6
--- /dev/null
+++ b/src/pcsc.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (c) 2022 Micro Focus or one of its affiliates.
+ * Copyright (c) 2022 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#if __APPLE__
+#include <PCSC/wintypes.h>
+#include <PCSC/winscard.h>
+#else
+#include <winscard.h>
+#endif /* __APPLE__ */
+
+#include <errno.h>
+
+#include "fido.h"
+#include "fido/param.h"
+#include "iso7816.h"
+
+#if defined(_WIN32) && !defined(__MINGW32__)
+#define SCardConnect SCardConnectA
+#define SCardListReaders SCardListReadersA
+#endif
+
+#ifndef SCARD_PROTOCOL_Tx
+#define SCARD_PROTOCOL_Tx SCARD_PROTOCOL_ANY
+#endif
+
+#define BUFSIZE 1024	/* in bytes; passed to SCardListReaders() */
+#define APDULEN 264	/* 261 rounded up to the nearest multiple of 8 */
+#define READERS 8	/* maximum number of readers */
+
+struct pcsc {
+	SCARDCONTEXT     ctx;
+	SCARDHANDLE      h;
+	SCARD_IO_REQUEST req;
+	uint8_t          rx_buf[APDULEN];
+	size_t           rx_len;
+};
+
+static LONG
+list_readers(SCARDCONTEXT ctx, char **buf)
+{
+	LONG s;
+	DWORD len;
+
+	len = BUFSIZE;
+	if ((*buf = calloc(1, len)) == NULL)
+		goto fail;
+	if ((s = SCardListReaders(ctx, NULL, *buf, &len)) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: SCardListReaders 0x%lx", __func__, (long)s);
+		goto fail;
+	}
+	/* sanity check "multi-string" */
+	if (len > BUFSIZE || len < 2) {
+		fido_log_debug("%s: bogus len=%u", __func__, (unsigned)len);
+		goto fail;
+	}
+	if ((*buf)[len - 1] != 0 || (*buf)[len - 2] != '\0') {
+		fido_log_debug("%s: bogus buf", __func__);
+		goto fail;
+	}
+	return (LONG)SCARD_S_SUCCESS;
+fail:
+	free(*buf);
+	*buf = NULL;
+
+	return (LONG)SCARD_E_NO_READERS_AVAILABLE;
+}
+
+static char *
+get_reader(SCARDCONTEXT ctx, const char *path)
+{
+	char *reader = NULL, *buf = NULL;
+	const char prefix[] = FIDO_PCSC_PREFIX "//slot";
+	uint64_t n;
+
+	if (path == NULL)
+		goto out;
+	if (strncmp(path, prefix, strlen(prefix)) != 0 ||
+	    fido_to_uint64(path + strlen(prefix), 10, &n) < 0 ||
+	    n > READERS - 1) {
+		fido_log_debug("%s: invalid path %s", __func__, path);
+		goto out;
+	}
+	if (list_readers(ctx, &buf) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: list_readers", __func__);
+		goto out;
+	}
+	for (const char *name = buf; *name != 0; name += strlen(name) + 1) {
+		if (n == 0) {
+			reader = strdup(name);
+			goto out;
+		}
+		n--;
+	}
+	fido_log_debug("%s: failed to find reader %s", __func__, path);
+out:
+	free(buf);
+
+	return reader;
+}
+
+static int
+prepare_io_request(DWORD prot, SCARD_IO_REQUEST *req)
+{
+	switch (prot) {
+	case SCARD_PROTOCOL_T0:
+		req->dwProtocol = SCARD_PCI_T0->dwProtocol;
+		req->cbPciLength = SCARD_PCI_T0->cbPciLength;
+		break;
+	case SCARD_PROTOCOL_T1:
+		req->dwProtocol = SCARD_PCI_T1->dwProtocol;
+		req->cbPciLength = SCARD_PCI_T1->cbPciLength;
+		break;
+	default:
+		fido_log_debug("%s: unknown protocol %lu", __func__,
+		    (u_long)prot);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+copy_info(fido_dev_info_t *di, SCARDCONTEXT ctx, const char *reader, size_t idx)
+{
+	SCARDHANDLE h = 0;
+	SCARD_IO_REQUEST req;
+	DWORD prot = 0;
+	LONG s;
+	int ok = -1;
+
+	memset(di, 0, sizeof(*di));
+	memset(&req, 0, sizeof(req));
+
+	if ((s = SCardConnect(ctx, reader, SCARD_SHARE_SHARED,
+	    SCARD_PROTOCOL_Tx, &h, &prot)) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: SCardConnect 0x%lx", __func__, (long)s);
+		goto fail;
+	}
+	if (prepare_io_request(prot, &req) < 0) {
+		fido_log_debug("%s: prepare_io_request", __func__);
+		goto fail;
+	}
+	if (asprintf(&di->path, "%s//slot%zu", FIDO_PCSC_PREFIX, idx) == -1) {
+		di->path = NULL;
+		fido_log_debug("%s: asprintf", __func__);
+		goto fail;
+	}
+	if (nfc_is_fido(di->path) == false) {
+		fido_log_debug("%s: nfc_is_fido: %s", __func__, di->path);
+		goto fail;
+	}
+	if ((di->manufacturer = strdup("PC/SC")) == NULL ||
+	    (di->product = strdup(reader)) == NULL)
+		goto fail;
+
+	ok = 0;
+fail:
+	if (h != 0)
+		SCardDisconnect(h, SCARD_LEAVE_CARD);
+	if (ok < 0) {
+		free(di->path);
+		free(di->manufacturer);
+		free(di->product);
+		explicit_bzero(di, sizeof(*di));
+	}
+
+	return ok;
+}
+
+int
+fido_pcsc_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
+{
+	SCARDCONTEXT ctx = 0;
+	char *buf = NULL;
+	LONG s;
+	size_t idx = 0;
+	int r = FIDO_ERR_INTERNAL;
+
+	*olen = 0;
+
+	if (ilen == 0)
+		return FIDO_OK;
+	if (devlist == NULL)
+		return FIDO_ERR_INVALID_ARGUMENT;
+
+	if ((s = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL,
+	    &ctx)) != SCARD_S_SUCCESS || ctx == 0) {
+		fido_log_debug("%s: SCardEstablishContext 0x%lx", __func__,
+		    (long)s);
+		if (s == (LONG)SCARD_E_NO_SERVICE ||
+		    s == (LONG)SCARD_E_NO_SMARTCARD)
+			r = FIDO_OK; /* suppress error */
+		goto out;
+	}
+	if ((s = list_readers(ctx, &buf)) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: list_readers 0x%lx", __func__, (long)s);
+		if (s == (LONG)SCARD_E_NO_READERS_AVAILABLE)
+			r = FIDO_OK; /* suppress error */
+		goto out;
+	}
+
+	for (const char *name = buf; *name != 0; name += strlen(name) + 1) {
+		if (idx == READERS) {
+			fido_log_debug("%s: stopping at %zu readers", __func__,
+			    idx);
+			r = FIDO_OK;
+			goto out;
+		}
+		if (copy_info(&devlist[*olen], ctx, name, idx++) == 0) {
+			devlist[*olen].io = (fido_dev_io_t) {
+				fido_pcsc_open,
+				fido_pcsc_close,
+				fido_pcsc_read,
+				fido_pcsc_write,
+			};
+			devlist[*olen].transport = (fido_dev_transport_t) {
+				fido_pcsc_rx,
+				fido_pcsc_tx,
+			};
+			if (++(*olen) == ilen)
+				break;
+		}
+	}
+
+	r = FIDO_OK;
+out:
+	free(buf);
+	if (ctx != 0)
+		SCardReleaseContext(ctx);
+
+	return r;
+}
+
+void *
+fido_pcsc_open(const char *path)
+{
+	char *reader = NULL;
+	struct pcsc *dev = NULL;
+	SCARDCONTEXT ctx = 0;
+	SCARDHANDLE h = 0;
+	SCARD_IO_REQUEST req;
+	DWORD prot = 0;
+	LONG s;
+
+	memset(&req, 0, sizeof(req));
+
+	if ((s = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL,
+	    &ctx)) != SCARD_S_SUCCESS || ctx == 0) {
+		fido_log_debug("%s: SCardEstablishContext 0x%lx", __func__,
+		    (long)s);
+		goto fail;
+
+	}
+	if ((reader = get_reader(ctx, path)) == NULL) {
+		fido_log_debug("%s: get_reader(%s)", __func__, path);
+		goto fail;
+	}
+	if ((s = SCardConnect(ctx, reader, SCARD_SHARE_SHARED,
+	    SCARD_PROTOCOL_Tx, &h, &prot)) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: SCardConnect 0x%lx", __func__, (long)s);
+		goto fail;
+	}
+	if (prepare_io_request(prot, &req) < 0) {
+		fido_log_debug("%s: prepare_io_request", __func__);
+		goto fail;
+	}
+	if ((dev = calloc(1, sizeof(*dev))) == NULL)
+		goto fail;
+
+	dev->ctx = ctx;
+	dev->h = h;
+	dev->req = req;
+	ctx = 0;
+	h = 0;
+fail:
+	if (h != 0)
+		SCardDisconnect(h, SCARD_LEAVE_CARD);
+	if (ctx != 0)
+		SCardReleaseContext(ctx);
+	free(reader);
+
+	return dev;
+}
+
+void
+fido_pcsc_close(void *handle)
+{
+	struct pcsc *dev = handle;
+
+	if (dev->h != 0)
+		SCardDisconnect(dev->h, SCARD_LEAVE_CARD);
+	if (dev->ctx != 0)
+		SCardReleaseContext(dev->ctx);
+
+	explicit_bzero(dev->rx_buf, sizeof(dev->rx_buf));
+	free(dev);
+}
+
+int
+fido_pcsc_read(void *handle, unsigned char *buf, size_t len, int ms)
+{
+	struct pcsc *dev = handle;
+	int r;
+
+	(void)ms;
+	if (dev->rx_len == 0 || dev->rx_len > len ||
+	    dev->rx_len > sizeof(dev->rx_buf)) {
+		fido_log_debug("%s: rx_len", __func__);
+		return -1;
+	}
+	fido_log_xxd(dev->rx_buf, dev->rx_len, "%s: reading", __func__);
+	memcpy(buf, dev->rx_buf, dev->rx_len);
+	explicit_bzero(dev->rx_buf, sizeof(dev->rx_buf));
+	r = (int)dev->rx_len;
+	dev->rx_len = 0;
+
+	return r;
+}
+
+int
+fido_pcsc_write(void *handle, const unsigned char *buf, size_t len)
+{
+	struct pcsc *dev = handle;
+	DWORD n;
+	LONG s;
+
+	if (len > INT_MAX) {
+		fido_log_debug("%s: len", __func__);
+		return -1;
+	}
+
+	explicit_bzero(dev->rx_buf, sizeof(dev->rx_buf));
+	dev->rx_len = 0;
+	n = (DWORD)sizeof(dev->rx_buf);
+
+	fido_log_xxd(buf, len, "%s: writing", __func__);
+
+	if ((s = SCardTransmit(dev->h, &dev->req, buf, (DWORD)len, NULL,
+	    dev->rx_buf, &n)) != SCARD_S_SUCCESS) {
+		fido_log_debug("%s: SCardTransmit 0x%lx", __func__, (long)s);
+		explicit_bzero(dev->rx_buf, sizeof(dev->rx_buf));
+		return -1;
+	}
+	dev->rx_len = (size_t)n;
+
+	fido_log_xxd(dev->rx_buf, dev->rx_len, "%s: read", __func__);
+
+	return (int)len;
+}
+
+int
+fido_pcsc_tx(fido_dev_t *d, uint8_t cmd, const u_char *buf, size_t count)
+{
+	return fido_nfc_tx(d, cmd, buf, count);
+}
+
+int
+fido_pcsc_rx(fido_dev_t *d, uint8_t cmd, u_char *buf, size_t count, int ms)
+{
+	return fido_nfc_rx(d, cmd, buf, count, ms);
+}
+
+bool
+fido_is_pcsc(const char *path)
+{
+	return strncmp(path, FIDO_PCSC_PREFIX, strlen(FIDO_PCSC_PREFIX)) == 0;
+}
+
+int
+fido_dev_set_pcsc(fido_dev_t *d)
+{
+	if (d->io_handle != NULL) {
+		fido_log_debug("%s: device open", __func__);
+		return -1;
+	}
+	d->io_own = true;
+	d->io = (fido_dev_io_t) {
+		fido_pcsc_open,
+		fido_pcsc_close,
+		fido_pcsc_read,
+		fido_pcsc_write,
+	};
+	d->transport = (fido_dev_transport_t) {
+		fido_pcsc_rx,
+		fido_pcsc_tx,
+	};
+
+	return 0;
+}