diff options
Diffstat (limited to 'fuzz/fuzz_largeblob.c')
| -rw-r--r-- | fuzz/fuzz_largeblob.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/fuzz/fuzz_largeblob.c b/fuzz/fuzz_largeblob.c new file mode 100644 index 0000000..6cdc0c0 --- /dev/null +++ b/fuzz/fuzz_largeblob.c @@ -0,0 +1,272 @@ +/* + * Copyright (c) 2020 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 <assert.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "mutator_aux.h" +#include "wiredata_fido2.h" +#include "dummy.h" + +#include "../openbsd-compat/openbsd-compat.h" + +/* Parameter set defining a FIDO2 "large blob" operation. */ +struct param { + char pin[MAXSTR]; + int seed; + struct blob key; + struct blob get_wiredata; + struct blob set_wiredata; +}; + +/* + * Collection of HID reports from an authenticator issued with a FIDO2 + * 'authenticatorLargeBlobs' 'get' command. + */ +static const uint8_t dummy_get_wiredata[] = { + WIREDATA_CTAP_INIT, + WIREDATA_CTAP_CBOR_INFO, + WIREDATA_CTAP_CBOR_LARGEBLOB_GET_ARRAY +}; + +/* + * Collection of HID reports from an authenticator issued with a FIDO2 + * 'authenticatorLargeBlobs' 'set' command. + */ +static const uint8_t dummy_set_wiredata[] = { + WIREDATA_CTAP_INIT, + WIREDATA_CTAP_CBOR_INFO, + WIREDATA_CTAP_CBOR_LARGEBLOB_GET_ARRAY, + WIREDATA_CTAP_CBOR_AUTHKEY, + WIREDATA_CTAP_CBOR_PINTOKEN, + WIREDATA_CTAP_CBOR_STATUS +}; + +/* + * XXX this needs to match the encrypted blob embedded in + * WIREDATA_CTAP_CBOR_LARGEBLOB_GET_ARRAY. + */ +static const uint8_t dummy_key[] = { + 0xa9, 0x1b, 0xc4, 0xdd, 0xfc, 0x9a, 0x93, 0x79, + 0x75, 0xba, 0xf7, 0x7f, 0x4d, 0x57, 0xfc, 0xa6, + 0xe1, 0xf8, 0x06, 0x43, 0x23, 0x99, 0x51, 0x32, + 0xce, 0x6e, 0x19, 0x84, 0x50, 0x13, 0x2d, 0x7b +}; + +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) != 5 || + (v = cbor_array_handle(item)) == NULL) + goto fail; + + if (unpack_int(v[0], &p->seed) < 0 || + unpack_string(v[1], p->pin) < 0 || + unpack_blob(v[2], &p->key) < 0 || + unpack_blob(v[3], &p->get_wiredata) < 0 || + unpack_blob(v[4], &p->set_wiredata) < 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[5], *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(5)) == NULL || + (argv[0] = pack_int(p->seed)) == NULL || + (argv[1] = pack_string(p->pin)) == NULL || + (argv[2] = pack_blob(&p->key)) == NULL || + (argv[3] = pack_blob(&p->get_wiredata)) == NULL || + (argv[4] = pack_blob(&p->set_wiredata)) == NULL) + goto fail; + + for (size_t i = 0; i < 5; i++) + if (cbor_array_push(array, argv[i]) == false) + goto fail; + + if ((cbor_len = cbor_serialize_alloc(array, &cbor, + &cbor_alloc_len)) == 0 || cbor_len > len) { + cbor_len = 0; + goto fail; + } + + memcpy(ptr, cbor, cbor_len); +fail: + for (size_t i = 0; i < 5; 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.pin, dummy_pin, sizeof(dummy.pin)); + + dummy.get_wiredata.len = sizeof(dummy_get_wiredata); + dummy.set_wiredata.len = sizeof(dummy_set_wiredata); + dummy.key.len = sizeof(dummy_key); + + memcpy(&dummy.get_wiredata.body, &dummy_get_wiredata, + dummy.get_wiredata.len); + memcpy(&dummy.set_wiredata.body, &dummy_set_wiredata, + dummy.set_wiredata.len); + memcpy(&dummy.key.body, &dummy_key, dummy.key.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 fido_dev_t * +prepare_dev(void) +{ + fido_dev_t *dev; + + if ((dev = open_dev(0)) == NULL) + return NULL; + + return dev; +} + +static void +get_blob(const struct param *p, int array) +{ + fido_dev_t *dev; + u_char *ptr = NULL; + size_t len = 0; + + set_wire_data(p->get_wiredata.body, p->get_wiredata.len); + + if ((dev = prepare_dev()) == NULL) + return; + + if (array) + fido_dev_largeblob_get_array(dev, &ptr, &len); + else + fido_dev_largeblob_get(dev, p->key.body, p->key.len, &ptr, &len); + consume(ptr, len); + free(ptr); + + fido_dev_close(dev); + fido_dev_free(&dev); +} + + +static void +set_blob(const struct param *p, int op) +{ + fido_dev_t *dev; + const char *pin; + + set_wire_data(p->set_wiredata.body, p->set_wiredata.len); + + if ((dev = prepare_dev()) == NULL) + return; + pin = p->pin; + if (strlen(pin) == 0) + pin = NULL; + + switch (op) { + case 0: + fido_dev_largeblob_remove(dev, p->key.body, p->key.len, pin); + break; + case 1: + /* XXX reuse p->get_wiredata as the blob to be set */ + fido_dev_largeblob_set(dev, p->key.body, p->key.len, + p->get_wiredata.body, p->get_wiredata.len, pin); + break; + case 2: + /* XXX reuse p->get_wiredata as the body of the cbor array */ + fido_dev_largeblob_set_array(dev, p->get_wiredata.body, + p->get_wiredata.len, pin); + } + + fido_dev_close(dev); + fido_dev_free(&dev); +} + +void +test(const struct param *p) +{ + prng_init((unsigned int)p->seed); + fuzz_clock_reset(); + fido_init(FIDO_DEBUG); + fido_set_log_handler(consume_str); + + get_blob(p, 0); + get_blob(p, 1); + set_blob(p, 0); + set_blob(p, 1); + set_blob(p, 2); +} + +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_blob(&p->key); + mutate_string(p->pin); + } + + if (flags & MUTATE_WIREDATA) { + mutate_blob(&p->get_wiredata); + mutate_blob(&p->set_wiredata); + } +} |