diff options
Diffstat (limited to '')
| -rw-r--r-- | fuzz/fuzz_pcsc.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/fuzz/fuzz_pcsc.c b/fuzz/fuzz_pcsc.c new file mode 100644 index 0000000..f0f6cca --- /dev/null +++ b/fuzz/fuzz_pcsc.c @@ -0,0 +1,269 @@ +/* + * 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 + */ + +#define _FIDO_INTERNAL + +#include <assert.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <winscard.h> + +#include "mutator_aux.h" +#include "wiredata_fido2.h" +#include "dummy.h" + +#include "../src/extern.h" + +struct param { + int seed; + char path[MAXSTR]; + struct blob pcsc_list; + struct blob tx_apdu; + struct blob wiredata_init; + struct blob wiredata_msg; +}; + +static const uint8_t dummy_tx_apdu[] = { WIREDATA_CTAP_EXTENDED_APDU }; +static const uint8_t dummy_wiredata_init[] = { WIREDATA_CTAP_NFC_INIT }; +static const uint8_t dummy_wiredata_msg[] = { WIREDATA_CTAP_NFC_MSG }; + +struct param * +unpack(const uint8_t *ptr, size_t len) +{ + cbor_item_t *item = NULL, **v; + struct cbor_load_result cbor; + struct param *p; + int ok = -1; + + if ((p = calloc(1, sizeof(*p))) == NULL || + (item = cbor_load(ptr, len, &cbor)) == NULL || + cbor.read != len || + cbor_isa_array(item) == false || + cbor_array_is_definite(item) == false || + cbor_array_size(item) != 6 || + (v = cbor_array_handle(item)) == NULL) + goto fail; + + if (unpack_int(v[0], &p->seed) < 0 || + unpack_string(v[1], p->path) < 0 || + unpack_blob(v[2], &p->pcsc_list) < 0 || + unpack_blob(v[3], &p->tx_apdu) < 0 || + unpack_blob(v[4], &p->wiredata_init) < 0 || + unpack_blob(v[5], &p->wiredata_msg) < 0) + goto fail; + + ok = 0; +fail: + if (ok < 0) { + free(p); + p = NULL; + } + + if (item) + cbor_decref(&item); + + return p; +} + +size_t +pack(uint8_t *ptr, size_t len, const struct param *p) +{ + cbor_item_t *argv[6], *array = NULL; + size_t cbor_alloc_len, cbor_len = 0; + unsigned char *cbor = NULL; + + memset(argv, 0, sizeof(argv)); + + if ((array = cbor_new_definite_array(6)) == NULL || + (argv[0] = pack_int(p->seed)) == NULL || + (argv[1] = pack_string(p->path)) == NULL || + (argv[2] = pack_blob(&p->pcsc_list)) == NULL || + (argv[3] = pack_blob(&p->tx_apdu)) == NULL || + (argv[4] = pack_blob(&p->wiredata_init)) == NULL || + (argv[5] = pack_blob(&p->wiredata_msg)) == NULL) + goto fail; + + for (size_t i = 0; i < 6; i++) + if (cbor_array_push(array, argv[i]) == false) + goto fail; + + if ((cbor_len = cbor_serialize_alloc(array, &cbor, + &cbor_alloc_len)) > len) { + cbor_len = 0; + goto fail; + } + + memcpy(ptr, cbor, cbor_len); +fail: + for (size_t i = 0; i < 6; i++) + if (argv[i]) + cbor_decref(&argv[i]); + + if (array) + cbor_decref(&array); + + free(cbor); + + return cbor_len; +} + +size_t +pack_dummy(uint8_t *ptr, size_t len) +{ + struct param dummy; + uint8_t blob[MAXCORPUS]; + size_t blob_len; + + memset(&dummy, 0, sizeof(dummy)); + + strlcpy(dummy.path, dummy_pcsc_path, sizeof(dummy.path)); + + dummy.pcsc_list.len = sizeof(dummy_pcsc_list); + memcpy(&dummy.pcsc_list.body, &dummy_pcsc_list, dummy.pcsc_list.len); + + dummy.tx_apdu.len = sizeof(dummy_tx_apdu); + memcpy(&dummy.tx_apdu.body, &dummy_tx_apdu, dummy.tx_apdu.len); + + dummy.wiredata_init.len = sizeof(dummy_wiredata_init); + memcpy(&dummy.wiredata_init.body, &dummy_wiredata_init, + dummy.wiredata_init.len); + + dummy.wiredata_msg.len = sizeof(dummy_wiredata_msg); + memcpy(&dummy.wiredata_msg.body, &dummy_wiredata_msg, + dummy.wiredata_msg.len); + + assert((blob_len = pack(blob, sizeof(blob), &dummy)) != 0); + + if (blob_len > len) { + memcpy(ptr, blob, len); + return len; + } + + memcpy(ptr, blob, blob_len); + + return blob_len; +} + +static void +test_manifest(void) +{ + size_t ndevs, nfound; + fido_dev_info_t *devlist = NULL; + int16_t vendor_id, product_id; + int r; + + r = fido_pcsc_manifest(NULL, 0, &nfound); + assert(r == FIDO_OK && nfound == 0); + r = fido_pcsc_manifest(NULL, 1, &nfound); + assert(r == FIDO_ERR_INVALID_ARGUMENT); + + ndevs = uniform_random(64); + if ((devlist = fido_dev_info_new(ndevs)) == NULL || + fido_pcsc_manifest(devlist, ndevs, &nfound) != FIDO_OK) + goto out; + + for (size_t i = 0; i < nfound; i++) { + const fido_dev_info_t *di = fido_dev_info_ptr(devlist, i); + consume_str(fido_dev_info_path(di)); + consume_str(fido_dev_info_manufacturer_string(di)); + consume_str(fido_dev_info_product_string(di)); + vendor_id = fido_dev_info_vendor(di); + product_id = fido_dev_info_product(di); + consume(&vendor_id, sizeof(vendor_id)); + consume(&product_id, sizeof(product_id)); + } + +out: + fido_dev_info_free(&devlist, ndevs); +} + +static void +test_tx(const char *path, const struct blob *apdu, uint8_t cmd, u_char *rx_buf, + size_t rx_len) +{ + fido_dev_t dev; + const u_char *tx_ptr = NULL; + size_t tx_len = 0; + int n; + + memset(&dev, 0, sizeof(dev)); + + if (fido_dev_set_pcsc(&dev) < 0) + return; + if ((dev.io_handle = fido_pcsc_open(path)) == NULL) + return; + + if (apdu) { + tx_ptr = apdu->body; + tx_len = apdu->len; + } + + fido_pcsc_tx(&dev, cmd, tx_ptr, tx_len); + + if ((n = fido_pcsc_rx(&dev, cmd, rx_buf, rx_len, -1)) >= 0) + consume(rx_buf, n); + + fido_pcsc_close(dev.io_handle); +} + +static void +test_misc(void) +{ + assert(fido_pcsc_open(NULL) == NULL); + assert(fido_pcsc_write(NULL, NULL, INT_MAX + 1LL) == -1); +} + +void +test(const struct param *p) +{ + u_char buf[512]; + + prng_init((unsigned int)p->seed); + fuzz_clock_reset(); + fido_init(FIDO_DEBUG); + fido_set_log_handler(consume_str); + + set_pcsc_parameters(&p->pcsc_list); + set_pcsc_io_functions(nfc_read, nfc_write, consume); + + set_wire_data(p->wiredata_init.body, p->wiredata_init.len); + test_manifest(); + + test_misc(); + + set_wire_data(p->wiredata_init.body, p->wiredata_init.len); + test_tx(p->path, NULL, CTAP_CMD_INIT, buf, uniform_random(20)); + + set_wire_data(p->wiredata_msg.body, p->wiredata_msg.len); + test_tx(p->path, &p->tx_apdu, CTAP_CMD_MSG, buf, sizeof(buf)); + + set_wire_data(p->wiredata_msg.body, p->wiredata_msg.len); + test_tx(p->path, &p->tx_apdu, CTAP_CMD_CBOR, buf, sizeof(buf)); + + set_wire_data(p->wiredata_msg.body, p->wiredata_msg.len); + test_tx(p->path, &p->tx_apdu, CTAP_CMD_LOCK, buf, sizeof(buf)); +} + +void +mutate(struct param *p, unsigned int seed, unsigned int flags) NO_MSAN +{ + if (flags & MUTATE_SEED) + p->seed = (int)seed; + + if (flags & MUTATE_PARAM) { + mutate_string(p->path); + mutate_blob(&p->pcsc_list); + mutate_blob(&p->tx_apdu); + } + + if (flags & MUTATE_WIREDATA) { + mutate_blob(&p->wiredata_init); + mutate_blob(&p->wiredata_msg); + } +} |