From cd13e2506379761d3464eae917eb1881876a7aa1 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:23:06 +0200 Subject: Adding upstream version 1.12.0. Signed-off-by: Daniel Baumann --- src/nfc.c | 350 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 350 insertions(+) create mode 100644 src/nfc.c (limited to 'src/nfc.c') diff --git a/src/nfc.c b/src/nfc.c new file mode 100644 index 0000000..2e97d5f --- /dev/null +++ b/src/nfc.c @@ -0,0 +1,350 @@ +/* + * Copyright (c) 2020-2022 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 + */ + +#include +#include + +#include "fido.h" +#include "fido/param.h" +#include "iso7816.h" + +#define TX_CHUNK_SIZE 240 + +static const uint8_t aid[] = { 0xa0, 0x00, 0x00, 0x06, 0x47, 0x2f, 0x00, 0x01 }; +static const uint8_t v_u2f[] = { 'U', '2', 'F', '_', 'V', '2' }; +static const uint8_t v_fido[] = { 'F', 'I', 'D', 'O', '_', '2', '_', '0' }; + +static int +tx_short_apdu(fido_dev_t *d, const iso7816_header_t *h, const uint8_t *payload, + uint8_t payload_len, uint8_t cla_flags) +{ + uint8_t apdu[5 + UINT8_MAX + 1]; + uint8_t sw[2]; + size_t apdu_len; + int ok = -1; + + memset(&apdu, 0, sizeof(apdu)); + apdu[0] = h->cla | cla_flags; + apdu[1] = h->ins; + apdu[2] = h->p1; + apdu[3] = h->p2; + apdu[4] = payload_len; + memcpy(&apdu[5], payload, payload_len); + apdu_len = (size_t)(5 + payload_len + 1); + + if (d->io.write(d->io_handle, apdu, apdu_len) < 0) { + fido_log_debug("%s: write", __func__); + goto fail; + } + + if (cla_flags & 0x10) { + if (d->io.read(d->io_handle, sw, sizeof(sw), -1) != 2) { + fido_log_debug("%s: read", __func__); + goto fail; + } + if ((sw[0] << 8 | sw[1]) != SW_NO_ERROR) { + fido_log_debug("%s: unexpected sw", __func__); + goto fail; + } + } + + ok = 0; +fail: + explicit_bzero(apdu, sizeof(apdu)); + + return ok; +} + +static int +nfc_do_tx(fido_dev_t *d, const uint8_t *apdu_ptr, size_t apdu_len) +{ + iso7816_header_t h; + + if (fido_buf_read(&apdu_ptr, &apdu_len, &h, sizeof(h)) < 0) { + fido_log_debug("%s: header", __func__); + return -1; + } + if (apdu_len < 2) { + fido_log_debug("%s: apdu_len %zu", __func__, apdu_len); + return -1; + } + + apdu_len -= 2; /* trim le1 le2 */ + + while (apdu_len > TX_CHUNK_SIZE) { + if (tx_short_apdu(d, &h, apdu_ptr, TX_CHUNK_SIZE, 0x10) < 0) { + fido_log_debug("%s: chain", __func__); + return -1; + } + apdu_ptr += TX_CHUNK_SIZE; + apdu_len -= TX_CHUNK_SIZE; + } + + if (tx_short_apdu(d, &h, apdu_ptr, (uint8_t)apdu_len, 0) < 0) { + fido_log_debug("%s: tx_short_apdu", __func__); + return -1; + } + + return 0; +} + +int +fido_nfc_tx(fido_dev_t *d, uint8_t cmd, const unsigned char *buf, size_t count) +{ + iso7816_apdu_t *apdu = NULL; + const uint8_t *ptr; + size_t len; + int ok = -1; + + switch (cmd) { + case CTAP_CMD_INIT: /* select */ + if ((apdu = iso7816_new(0, 0xa4, 0x04, sizeof(aid))) == NULL || + iso7816_add(apdu, aid, sizeof(aid)) < 0) { + fido_log_debug("%s: iso7816", __func__); + goto fail; + } + break; + case CTAP_CMD_CBOR: /* wrap cbor */ + if (count > UINT16_MAX || (apdu = iso7816_new(0x80, 0x10, 0x00, + (uint16_t)count)) == NULL || + iso7816_add(apdu, buf, count) < 0) { + fido_log_debug("%s: iso7816", __func__); + goto fail; + } + break; + case CTAP_CMD_MSG: /* already an apdu */ + break; + default: + fido_log_debug("%s: cmd=%02x", __func__, cmd); + goto fail; + } + + if (apdu != NULL) { + ptr = iso7816_ptr(apdu); + len = iso7816_len(apdu); + } else { + ptr = buf; + len = count; + } + + if (nfc_do_tx(d, ptr, len) < 0) { + fido_log_debug("%s: nfc_do_tx", __func__); + goto fail; + } + + ok = 0; +fail: + iso7816_free(&apdu); + + return ok; +} + +static int +rx_init(fido_dev_t *d, unsigned char *buf, size_t count, int ms) +{ + fido_ctap_info_t *attr = (fido_ctap_info_t *)buf; + uint8_t f[64]; + int n; + + if (count != sizeof(*attr)) { + fido_log_debug("%s: count=%zu", __func__, count); + return -1; + } + + memset(attr, 0, sizeof(*attr)); + + if ((n = d->io.read(d->io_handle, f, sizeof(f), ms)) < 2 || + (f[n - 2] << 8 | f[n - 1]) != SW_NO_ERROR) { + fido_log_debug("%s: read", __func__); + return -1; + } + + n -= 2; + + if (n == sizeof(v_u2f) && memcmp(f, v_u2f, sizeof(v_u2f)) == 0) + attr->flags = FIDO_CAP_CBOR; + else if (n == sizeof(v_fido) && memcmp(f, v_fido, sizeof(v_fido)) == 0) + attr->flags = FIDO_CAP_CBOR | FIDO_CAP_NMSG; + else { + fido_log_debug("%s: unknown version string", __func__); +#ifdef FIDO_FUZZ + attr->flags = FIDO_CAP_CBOR | FIDO_CAP_NMSG; +#else + return -1; +#endif + } + + memcpy(&attr->nonce, &d->nonce, sizeof(attr->nonce)); /* XXX */ + + return (int)count; +} + +static int +tx_get_response(fido_dev_t *d, uint8_t count) +{ + uint8_t apdu[5]; + + memset(apdu, 0, sizeof(apdu)); + apdu[1] = 0xc0; /* GET_RESPONSE */ + apdu[4] = count; + + if (d->io.write(d->io_handle, apdu, sizeof(apdu)) < 0) { + fido_log_debug("%s: write", __func__); + return -1; + } + + return 0; +} + +static int +rx_apdu(fido_dev_t *d, uint8_t sw[2], unsigned char **buf, size_t *count, int *ms) +{ + uint8_t f[256 + 2]; + struct timespec ts; + int n, ok = -1; + + if (fido_time_now(&ts) != 0) + goto fail; + + if ((n = d->io.read(d->io_handle, f, sizeof(f), *ms)) < 2) { + fido_log_debug("%s: read", __func__); + goto fail; + } + + if (fido_time_delta(&ts, ms) != 0) + goto fail; + + if (fido_buf_write(buf, count, f, (size_t)(n - 2)) < 0) { + fido_log_debug("%s: fido_buf_write", __func__); + goto fail; + } + + memcpy(sw, f + n - 2, 2); + + ok = 0; +fail: + explicit_bzero(f, sizeof(f)); + + return ok; +} + +static int +rx_msg(fido_dev_t *d, unsigned char *buf, size_t count, int ms) +{ + uint8_t sw[2]; + const size_t bufsiz = count; + + if (rx_apdu(d, sw, &buf, &count, &ms) < 0) { + fido_log_debug("%s: preamble", __func__); + return -1; + } + + while (sw[0] == SW1_MORE_DATA) + if (tx_get_response(d, sw[1]) < 0 || + rx_apdu(d, sw, &buf, &count, &ms) < 0) { + fido_log_debug("%s: chain", __func__); + return -1; + } + + if (fido_buf_write(&buf, &count, sw, sizeof(sw)) < 0) { + fido_log_debug("%s: sw", __func__); + return -1; + } + + if (bufsiz - count > INT_MAX) { + fido_log_debug("%s: bufsiz", __func__); + return -1; + } + + return (int)(bufsiz - count); +} + +static int +rx_cbor(fido_dev_t *d, unsigned char *buf, size_t count, int ms) +{ + int r; + + if ((r = rx_msg(d, buf, count, ms)) < 2) + return -1; + + return r - 2; +} + +int +fido_nfc_rx(fido_dev_t *d, uint8_t cmd, unsigned char *buf, size_t count, int ms) +{ + switch (cmd) { + case CTAP_CMD_INIT: + return rx_init(d, buf, count, ms); + case CTAP_CMD_CBOR: + return rx_cbor(d, buf, count, ms); + case CTAP_CMD_MSG: + return rx_msg(d, buf, count, ms); + default: + fido_log_debug("%s: cmd=%02x", __func__, cmd); + return -1; + } +} + +bool +nfc_is_fido(const char *path) +{ + bool fido = false; + fido_dev_t *d; + int r; + + if ((d = fido_dev_new()) == NULL) { + fido_log_debug("%s: fido_dev_new", __func__); + goto fail; + } + /* fido_dev_open selects the fido applet */ + if ((r = fido_dev_open(d, path)) != FIDO_OK) { + fido_log_debug("%s: fido_dev_open: 0x%x", __func__, r); + goto fail; + } + if ((r = fido_dev_close(d)) != FIDO_OK) { + fido_log_debug("%s: fido_dev_close: 0x%x", __func__, r); + goto fail; + + } + + fido = true; +fail: + fido_dev_free(&d); + + return fido; +} + +#ifdef USE_NFC +bool +fido_is_nfc(const char *path) +{ + return strncmp(path, FIDO_NFC_PREFIX, strlen(FIDO_NFC_PREFIX)) == 0; +} + +int +fido_dev_set_nfc(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_nfc_open, + fido_nfc_close, + fido_nfc_read, + fido_nfc_write, + }; + d->transport = (fido_dev_transport_t) { + fido_nfc_rx, + fido_nfc_tx, + }; + + return 0; +} +#endif /* USE_NFC */ -- cgit v1.2.3