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-rw-r--r--fuzz/fuzz_assert.c532
1 files changed, 532 insertions, 0 deletions
diff --git a/fuzz/fuzz_assert.c b/fuzz/fuzz_assert.c
new file mode 100644
index 0000000..603957e
--- /dev/null
+++ b/fuzz/fuzz_assert.c
@@ -0,0 +1,532 @@
+/*
+ * Copyright (c) 2019-2022 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 <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mutator_aux.h"
+#include "wiredata_fido2.h"
+#include "wiredata_u2f.h"
+#include "dummy.h"
+
+#include "../openbsd-compat/openbsd-compat.h"
+
+/* Parameter set defining a FIDO2 get assertion operation. */
+struct param {
+ char pin[MAXSTR];
+ char rp_id[MAXSTR];
+ int ext;
+ int seed;
+ struct blob cdh;
+ struct blob cred;
+ struct blob es256;
+ struct blob rs256;
+ struct blob eddsa;
+ struct blob wire_data;
+ uint8_t cred_count;
+ uint8_t type;
+ uint8_t opt;
+ uint8_t up;
+ uint8_t uv;
+};
+
+/*
+ * Collection of HID reports from an authenticator issued with a FIDO2
+ * get assertion using the example parameters above.
+ */
+static const uint8_t dummy_wire_data_fido[] = {
+ WIREDATA_CTAP_INIT,
+ WIREDATA_CTAP_CBOR_INFO,
+ WIREDATA_CTAP_CBOR_AUTHKEY,
+ WIREDATA_CTAP_CBOR_PINTOKEN,
+ WIREDATA_CTAP_CBOR_ASSERT,
+};
+
+/*
+ * Collection of HID reports from an authenticator issued with a U2F
+ * authentication using the example parameters above.
+ */
+static const uint8_t dummy_wire_data_u2f[] = {
+ WIREDATA_CTAP_INIT,
+ WIREDATA_CTAP_U2F_6985,
+ WIREDATA_CTAP_U2F_6985,
+ WIREDATA_CTAP_U2F_6985,
+ WIREDATA_CTAP_U2F_6985,
+ WIREDATA_CTAP_U2F_AUTH,
+};
+
+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) != 15 ||
+ (v = cbor_array_handle(item)) == NULL)
+ goto fail;
+
+ if (unpack_byte(v[0], &p->uv) < 0 ||
+ unpack_byte(v[1], &p->up) < 0 ||
+ unpack_byte(v[2], &p->opt) < 0 ||
+ unpack_byte(v[3], &p->type) < 0 ||
+ unpack_byte(v[4], &p->cred_count) < 0 ||
+ unpack_int(v[5], &p->ext) < 0 ||
+ unpack_int(v[6], &p->seed) < 0 ||
+ unpack_string(v[7], p->rp_id) < 0 ||
+ unpack_string(v[8], p->pin) < 0 ||
+ unpack_blob(v[9], &p->wire_data) < 0 ||
+ unpack_blob(v[10], &p->rs256) < 0 ||
+ unpack_blob(v[11], &p->es256) < 0 ||
+ unpack_blob(v[12], &p->eddsa) < 0 ||
+ unpack_blob(v[13], &p->cred) < 0 ||
+ unpack_blob(v[14], &p->cdh) < 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[15], *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(15)) == NULL ||
+ (argv[0] = pack_byte(p->uv)) == NULL ||
+ (argv[1] = pack_byte(p->up)) == NULL ||
+ (argv[2] = pack_byte(p->opt)) == NULL ||
+ (argv[3] = pack_byte(p->type)) == NULL ||
+ (argv[4] = pack_byte(p->cred_count)) == NULL ||
+ (argv[5] = pack_int(p->ext)) == NULL ||
+ (argv[6] = pack_int(p->seed)) == NULL ||
+ (argv[7] = pack_string(p->rp_id)) == NULL ||
+ (argv[8] = pack_string(p->pin)) == NULL ||
+ (argv[9] = pack_blob(&p->wire_data)) == NULL ||
+ (argv[10] = pack_blob(&p->rs256)) == NULL ||
+ (argv[11] = pack_blob(&p->es256)) == NULL ||
+ (argv[12] = pack_blob(&p->eddsa)) == NULL ||
+ (argv[13] = pack_blob(&p->cred)) == NULL ||
+ (argv[14] = pack_blob(&p->cdh)) == NULL)
+ goto fail;
+
+ for (size_t i = 0; i < 15; 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 < 15; 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));
+
+ dummy.type = 1; /* rsa */
+ dummy.ext = FIDO_EXT_HMAC_SECRET;
+
+ strlcpy(dummy.pin, dummy_pin, sizeof(dummy.pin));
+ strlcpy(dummy.rp_id, dummy_rp_id, sizeof(dummy.rp_id));
+
+ dummy.cred.len = sizeof(dummy_cdh); /* XXX */
+ dummy.cdh.len = sizeof(dummy_cdh);
+ dummy.es256.len = sizeof(dummy_es256);
+ dummy.rs256.len = sizeof(dummy_rs256);
+ dummy.eddsa.len = sizeof(dummy_eddsa);
+ dummy.wire_data.len = sizeof(dummy_wire_data_fido);
+
+ memcpy(&dummy.cred.body, &dummy_cdh, dummy.cred.len); /* XXX */
+ memcpy(&dummy.cdh.body, &dummy_cdh, dummy.cdh.len);
+ memcpy(&dummy.wire_data.body, &dummy_wire_data_fido,
+ dummy.wire_data.len);
+ memcpy(&dummy.es256.body, &dummy_es256, dummy.es256.len);
+ memcpy(&dummy.rs256.body, &dummy_rs256, dummy.rs256.len);
+ memcpy(&dummy.eddsa.body, &dummy_eddsa, dummy.eddsa.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
+get_assert(fido_assert_t *assert, uint8_t opt, const struct blob *cdh,
+ const char *rp_id, int ext, uint8_t up, uint8_t uv, const char *pin,
+ uint8_t cred_count, const struct blob *cred)
+{
+ fido_dev_t *dev;
+
+ if ((dev = open_dev(opt & 2)) == NULL)
+ return;
+ if (opt & 1)
+ fido_dev_force_u2f(dev);
+ if (ext & FIDO_EXT_HMAC_SECRET)
+ fido_assert_set_extensions(assert, FIDO_EXT_HMAC_SECRET);
+ if (ext & FIDO_EXT_CRED_BLOB)
+ fido_assert_set_extensions(assert, FIDO_EXT_CRED_BLOB);
+ if (ext & FIDO_EXT_LARGEBLOB_KEY)
+ fido_assert_set_extensions(assert, FIDO_EXT_LARGEBLOB_KEY);
+ if (up & 1)
+ fido_assert_set_up(assert, FIDO_OPT_TRUE);
+ else if (opt & 1)
+ fido_assert_set_up(assert, FIDO_OPT_FALSE);
+ if (uv & 1)
+ fido_assert_set_uv(assert, FIDO_OPT_TRUE);
+
+ for (uint8_t i = 0; i < cred_count; i++)
+ fido_assert_allow_cred(assert, cred->body, cred->len);
+
+ fido_assert_set_clientdata_hash(assert, cdh->body, cdh->len);
+ fido_assert_set_rp(assert, rp_id);
+ /* XXX reuse cred as hmac salt */
+ fido_assert_set_hmac_salt(assert, cred->body, cred->len);
+
+ /* repeat memory operations to trigger reallocation paths */
+ fido_assert_set_clientdata_hash(assert, cdh->body, cdh->len);
+ fido_assert_set_rp(assert, rp_id);
+ fido_assert_set_hmac_salt(assert, cred->body, cred->len);
+
+ if (strlen(pin) == 0)
+ pin = NULL;
+
+ fido_dev_get_assert(dev, assert, (opt & 1) ? NULL : pin);
+
+ fido_dev_cancel(dev);
+ fido_dev_close(dev);
+ fido_dev_free(&dev);
+}
+
+static void
+verify_assert(int type, const unsigned char *cdh_ptr, size_t cdh_len,
+ const char *rp_id, const unsigned char *authdata_ptr, size_t authdata_len,
+ const unsigned char *sig_ptr, size_t sig_len, uint8_t up, uint8_t uv,
+ int ext, void *pk)
+{
+ fido_assert_t *assert = NULL;
+ int r;
+
+ if ((assert = fido_assert_new()) == NULL)
+ return;
+
+ fido_assert_set_clientdata_hash(assert, cdh_ptr, cdh_len);
+ fido_assert_set_rp(assert, rp_id);
+ fido_assert_set_count(assert, 1);
+
+ if (fido_assert_set_authdata(assert, 0, authdata_ptr,
+ authdata_len) != FIDO_OK) {
+ fido_assert_set_authdata_raw(assert, 0, authdata_ptr,
+ authdata_len);
+ }
+
+ if (up & 1)
+ fido_assert_set_up(assert, FIDO_OPT_TRUE);
+ if (uv & 1)
+ fido_assert_set_uv(assert, FIDO_OPT_TRUE);
+
+ fido_assert_set_extensions(assert, ext);
+ fido_assert_set_sig(assert, 0, sig_ptr, sig_len);
+
+ /* repeat memory operations to trigger reallocation paths */
+ if (fido_assert_set_authdata(assert, 0, authdata_ptr,
+ authdata_len) != FIDO_OK) {
+ fido_assert_set_authdata_raw(assert, 0, authdata_ptr,
+ authdata_len);
+ }
+ fido_assert_set_sig(assert, 0, sig_ptr, sig_len);
+
+ r = fido_assert_verify(assert, 0, type, pk);
+ consume(&r, sizeof(r));
+
+ fido_assert_free(&assert);
+}
+
+/*
+ * Do a dummy conversion to exercise es256_pk_from_EVP_PKEY().
+ */
+static void
+es256_convert(const es256_pk_t *k)
+{
+ EVP_PKEY *pkey = NULL;
+ es256_pk_t *pk = NULL;
+ int r;
+
+ if ((pkey = es256_pk_to_EVP_PKEY(k)) == NULL ||
+ (pk = es256_pk_new()) == NULL)
+ goto out;
+
+ r = es256_pk_from_EVP_PKEY(pk, pkey);
+ consume(&r, sizeof(r));
+out:
+ es256_pk_free(&pk);
+ EVP_PKEY_free(pkey);
+}
+
+/*
+ * Do a dummy conversion to exercise es384_pk_from_EVP_PKEY().
+ */
+static void
+es384_convert(const es384_pk_t *k)
+{
+ EVP_PKEY *pkey = NULL;
+ es384_pk_t *pk = NULL;
+ int r;
+
+ if ((pkey = es384_pk_to_EVP_PKEY(k)) == NULL ||
+ (pk = es384_pk_new()) == NULL)
+ goto out;
+
+ r = es384_pk_from_EVP_PKEY(pk, pkey);
+ consume(&r, sizeof(r));
+out:
+ es384_pk_free(&pk);
+ EVP_PKEY_free(pkey);
+}
+
+/*
+ * Do a dummy conversion to exercise rs256_pk_from_EVP_PKEY().
+ */
+static void
+rs256_convert(const rs256_pk_t *k)
+{
+ EVP_PKEY *pkey = NULL;
+ rs256_pk_t *pk = NULL;
+ int r;
+
+ if ((pkey = rs256_pk_to_EVP_PKEY(k)) == NULL ||
+ (pk = rs256_pk_new()) == NULL)
+ goto out;
+
+ r = rs256_pk_from_EVP_PKEY(pk, pkey);
+ consume(&r, sizeof(r));
+out:
+ rs256_pk_free(&pk);
+ EVP_PKEY_free(pkey);
+}
+
+/*
+ * Do a dummy conversion to exercise eddsa_pk_from_EVP_PKEY().
+ */
+static void
+eddsa_convert(const eddsa_pk_t *k)
+{
+ EVP_PKEY *pkey = NULL;
+ eddsa_pk_t *pk = NULL;
+ int r;
+
+ if ((pkey = eddsa_pk_to_EVP_PKEY(k)) == NULL ||
+ (pk = eddsa_pk_new()) == NULL)
+ goto out;
+
+ r = eddsa_pk_from_EVP_PKEY(pk, pkey);
+ consume(&r, sizeof(r));
+out:
+ if (pk)
+ eddsa_pk_free(&pk);
+ if (pkey)
+ EVP_PKEY_free(pkey);
+}
+
+void
+test(const struct param *p)
+{
+ fido_assert_t *assert = NULL;
+ es256_pk_t *es256_pk = NULL;
+ es384_pk_t *es384_pk = NULL;
+ rs256_pk_t *rs256_pk = NULL;
+ eddsa_pk_t *eddsa_pk = NULL;
+ uint8_t flags;
+ uint32_t sigcount;
+ int cose_alg = 0;
+ void *pk;
+
+ prng_init((unsigned int)p->seed);
+ fuzz_clock_reset();
+ fido_init(FIDO_DEBUG);
+ fido_set_log_handler(consume_str);
+
+ switch (p->type & 3) {
+ case 0:
+ cose_alg = COSE_ES256;
+
+ if ((es256_pk = es256_pk_new()) == NULL)
+ return;
+
+ es256_pk_from_ptr(es256_pk, p->es256.body, p->es256.len);
+ pk = es256_pk;
+
+ es256_convert(pk);
+
+ break;
+ case 1:
+ cose_alg = COSE_RS256;
+
+ if ((rs256_pk = rs256_pk_new()) == NULL)
+ return;
+
+ rs256_pk_from_ptr(rs256_pk, p->rs256.body, p->rs256.len);
+ pk = rs256_pk;
+
+ rs256_convert(pk);
+
+ break;
+ case 2:
+ cose_alg = COSE_ES384;
+
+ if ((es384_pk = es384_pk_new()) == NULL)
+ return;
+
+ /* XXX reuse p->es256 as es384 */
+ es384_pk_from_ptr(es384_pk, p->es256.body, p->es256.len);
+ pk = es384_pk;
+
+ es384_convert(pk);
+
+ break;
+ default:
+ cose_alg = COSE_EDDSA;
+
+ if ((eddsa_pk = eddsa_pk_new()) == NULL)
+ return;
+
+ eddsa_pk_from_ptr(eddsa_pk, p->eddsa.body, p->eddsa.len);
+ pk = eddsa_pk;
+
+ eddsa_convert(pk);
+
+ break;
+ }
+
+ if ((assert = fido_assert_new()) == NULL)
+ goto out;
+
+ set_wire_data(p->wire_data.body, p->wire_data.len);
+
+ get_assert(assert, p->opt, &p->cdh, p->rp_id, p->ext, p->up, p->uv,
+ p->pin, p->cred_count, &p->cred);
+
+ /* XXX +1 on purpose */
+ for (size_t i = 0; i <= fido_assert_count(assert); i++) {
+ verify_assert(cose_alg,
+ fido_assert_clientdata_hash_ptr(assert),
+ fido_assert_clientdata_hash_len(assert),
+ fido_assert_rp_id(assert),
+ fido_assert_authdata_ptr(assert, i),
+ fido_assert_authdata_len(assert, i),
+ fido_assert_sig_ptr(assert, i),
+ fido_assert_sig_len(assert, i), p->up, p->uv, p->ext, pk);
+ consume(fido_assert_id_ptr(assert, i),
+ fido_assert_id_len(assert, i));
+ consume(fido_assert_user_id_ptr(assert, i),
+ fido_assert_user_id_len(assert, i));
+ consume(fido_assert_hmac_secret_ptr(assert, i),
+ fido_assert_hmac_secret_len(assert, i));
+ consume_str(fido_assert_user_icon(assert, i));
+ consume_str(fido_assert_user_name(assert, i));
+ consume_str(fido_assert_user_display_name(assert, i));
+ consume(fido_assert_blob_ptr(assert, i),
+ fido_assert_blob_len(assert, i));
+ consume(fido_assert_largeblob_key_ptr(assert, i),
+ fido_assert_largeblob_key_len(assert, i));
+ flags = fido_assert_flags(assert, i);
+ consume(&flags, sizeof(flags));
+ sigcount = fido_assert_sigcount(assert, i);
+ consume(&sigcount, sizeof(sigcount));
+ }
+
+out:
+ es256_pk_free(&es256_pk);
+ es384_pk_free(&es384_pk);
+ rs256_pk_free(&rs256_pk);
+ eddsa_pk_free(&eddsa_pk);
+
+ fido_assert_free(&assert);
+}
+
+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_byte(&p->uv);
+ mutate_byte(&p->up);
+ mutate_byte(&p->opt);
+ mutate_byte(&p->type);
+ mutate_byte(&p->cred_count);
+ mutate_int(&p->ext);
+ mutate_blob(&p->rs256);
+ mutate_blob(&p->es256);
+ mutate_blob(&p->eddsa);
+ mutate_blob(&p->cred);
+ mutate_blob(&p->cdh);
+ mutate_string(p->rp_id);
+ mutate_string(p->pin);
+ }
+
+ if (flags & MUTATE_WIREDATA) {
+ if (p->opt & 1) {
+ p->wire_data.len = sizeof(dummy_wire_data_u2f);
+ memcpy(&p->wire_data.body, &dummy_wire_data_u2f,
+ p->wire_data.len);
+ } else {
+ p->wire_data.len = sizeof(dummy_wire_data_fido);
+ memcpy(&p->wire_data.body, &dummy_wire_data_fido,
+ p->wire_data.len);
+ }
+ mutate_blob(&p->wire_data);
+ }
+}