libfido2/fuzz/fuzz_attobj.c

/*
 * Copyright (c) 2024 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
 */

#undef NDEBUG

#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"

struct param {
	int seed;
	char rp_id[MAXSTR];
	struct blob cdh;
	struct blob attobj;
	uint8_t type;
};

static const uint8_t dummy_attestation_object[] = {
	0xa3, 0x63, 0x66, 0x6d, 0x74, 0x66, 0x70, 0x61,
	0x63, 0x6b, 0x65, 0x64, 0x67, 0x61, 0x74, 0x74,
	0x53, 0x74, 0x6d, 0x74, 0xa3, 0x63, 0x61, 0x6c,
	0x67, 0x26, 0x63, 0x73, 0x69, 0x67, 0x58, 0x46,
	0x30, 0x44, 0x02, 0x20, 0x54, 0x92, 0x28, 0x3b,
	0x83, 0x33, 0x47, 0x56, 0x68, 0x79, 0xb2, 0x0c,
	0x84, 0x80, 0xcc, 0x67, 0x27, 0x8b, 0xfa, 0x48,
	0x43, 0x0d, 0x3c, 0xb4, 0x02, 0x36, 0x87, 0x97,
	0x3e, 0xdf, 0x2f, 0x65, 0x02, 0x20, 0x1b, 0x56,
	0x17, 0x06, 0xe2, 0x26, 0x0f, 0x6a, 0xe9, 0xa9,
	0x70, 0x99, 0x62, 0xeb, 0x3a, 0x04, 0x1a, 0xc4,
	0xa7, 0x03, 0x28, 0x56, 0x7c, 0xed, 0x47, 0x08,
	0x68, 0x73, 0x6a, 0xb6, 0x89, 0x0d, 0x63, 0x78,
	0x35, 0x63, 0x81, 0x59, 0x02, 0xe6, 0x30, 0x82,
	0x02, 0xe2, 0x30, 0x81, 0xcb, 0x02, 0x01, 0x01,
	0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
	0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x30,
	0x1d, 0x31, 0x1b, 0x30, 0x19, 0x06, 0x03, 0x55,
	0x04, 0x03, 0x13, 0x12, 0x59, 0x75, 0x62, 0x69,
	0x63, 0x6f, 0x20, 0x55, 0x32, 0x46, 0x20, 0x54,
	0x65, 0x73, 0x74, 0x20, 0x43, 0x41, 0x30, 0x1e,
	0x17, 0x0d, 0x31, 0x34, 0x30, 0x35, 0x31, 0x35,
	0x31, 0x32, 0x35, 0x38, 0x35, 0x34, 0x5a, 0x17,
	0x0d, 0x31, 0x34, 0x30, 0x36, 0x31, 0x34, 0x31,
	0x32, 0x35, 0x38, 0x35, 0x34, 0x5a, 0x30, 0x1d,
	0x31, 0x1b, 0x30, 0x19, 0x06, 0x03, 0x55, 0x04,
	0x03, 0x13, 0x12, 0x59, 0x75, 0x62, 0x69, 0x63,
	0x6f, 0x20, 0x55, 0x32, 0x46, 0x20, 0x54, 0x65,
	0x73, 0x74, 0x20, 0x45, 0x45, 0x30, 0x59, 0x30,
	0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d,
	0x02, 0x01, 0x06, 0x08, 0x2a, 0x86, 0x48, 0xce,
	0x3d, 0x03, 0x01, 0x07, 0x03, 0x42, 0x00, 0x04,
	0xdb, 0x0a, 0xdb, 0xf5, 0x21, 0xc7, 0x5c, 0xce,
	0x63, 0xdc, 0xa6, 0xe1, 0xe8, 0x25, 0x06, 0x0d,
	0x94, 0xe6, 0x27, 0x54, 0x19, 0x4f, 0x9d, 0x24,
	0xaf, 0x26, 0x1a, 0xbe, 0xad, 0x99, 0x44, 0x1f,
	0x95, 0xa3, 0x71, 0x91, 0x0a, 0x3a, 0x20, 0xe7,
	0x3e, 0x91, 0x5e, 0x13, 0xe8, 0xbe, 0x38, 0x05,
	0x7a, 0xd5, 0x7a, 0xa3, 0x7e, 0x76, 0x90, 0x8f,
	0xaf, 0xe2, 0x8a, 0x94, 0xb6, 0x30, 0xeb, 0x9d,
	0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
	0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x03,
	0x82, 0x02, 0x01, 0x00, 0x95, 0x40, 0x6b, 0x50,
	0x61, 0x7d, 0xad, 0x84, 0xa3, 0xb4, 0xeb, 0x88,
	0x0f, 0xe3, 0x30, 0x0f, 0x2d, 0xa2, 0x0a, 0x00,
	0xd9, 0x25, 0x04, 0xee, 0x72, 0xfa, 0x67, 0xdf,
	0x58, 0x51, 0x0f, 0x0b, 0x47, 0x02, 0x9c, 0x3e,
	0x41, 0x29, 0x4a, 0x93, 0xac, 0x29, 0x85, 0x89,
	0x2d, 0xa4, 0x7a, 0x81, 0x32, 0x28, 0x57, 0x71,
	0x01, 0xef, 0xa8, 0x42, 0x88, 0x16, 0x96, 0x37,
	0x91, 0xd5, 0xdf, 0xe0, 0x8f, 0xc9, 0x3c, 0x8d,
	0xb0, 0xcd, 0x89, 0x70, 0x82, 0xec, 0x79, 0xd3,
	0xc6, 0x78, 0x73, 0x29, 0x32, 0xe5, 0xab, 0x6c,
	0xbd, 0x56, 0x9f, 0xd5, 0x45, 0x91, 0xce, 0xc1,
	0xdd, 0x8d, 0x64, 0xdc, 0xe9, 0x9c, 0x1f, 0x5e,
	0x3c, 0xd2, 0xaf, 0x51, 0xa5, 0x82, 0x18, 0xaf,
	0xe0, 0x37, 0xe7, 0x32, 0x9e, 0x76, 0x05, 0x77,
	0x02, 0x7b, 0xe6, 0x24, 0xa0, 0x31, 0x56, 0x1b,
	0xfd, 0x19, 0xc5, 0x71, 0xd3, 0xf0, 0x9e, 0xc0,
	0x73, 0x05, 0x4e, 0xbc, 0x85, 0xb8, 0x53, 0x9e,
	0xef, 0xc5, 0xbc, 0x9c, 0x56, 0xa3, 0xba, 0xd9,
	0x27, 0x6a, 0xbb, 0xa9, 0x7a, 0x40, 0xd7, 0x47,
	0x8b, 0x55, 0x72, 0x6b, 0xe3, 0xfe, 0x28, 0x49,
	0x71, 0x24, 0xf4, 0x8f, 0xf4, 0x20, 0x81, 0xea,
	0x38, 0xff, 0x7c, 0x0a, 0x4f, 0xdf, 0x02, 0x82,
	0x39, 0x81, 0x82, 0x3b, 0xca, 0x09, 0xdd, 0xca,
	0xaa, 0x0f, 0x27, 0xf5, 0xa4, 0x83, 0x55, 0x6c,
	0x9a, 0x39, 0x9b, 0x15, 0x3a, 0x16, 0x63, 0xdc,
	0x5b, 0xf9, 0xac, 0x5b, 0xbc, 0xf7, 0x9f, 0xbe,
	0x0f, 0x8a, 0xa2, 0x3c, 0x31, 0x13, 0xa3, 0x32,
	0x48, 0xca, 0x58, 0x87, 0xf8, 0x7b, 0xa0, 0xa1,
	0x0a, 0x6a, 0x60, 0x96, 0x93, 0x5f, 0x5d, 0x26,
	0x9e, 0x63, 0x1d, 0x09, 0xae, 0x9a, 0x41, 0xe5,
	0xbd, 0x08, 0x47, 0xfe, 0xe5, 0x09, 0x9b, 0x20,
	0xfd, 0x12, 0xe2, 0xe6, 0x40, 0x7f, 0xba, 0x4a,
	0x61, 0x33, 0x66, 0x0d, 0x0e, 0x73, 0xdb, 0xb0,
	0xd5, 0xa2, 0x9a, 0x9a, 0x17, 0x0d, 0x34, 0x30,
	0x85, 0x6a, 0x42, 0x46, 0x9e, 0xff, 0x34, 0x8f,
	0x5f, 0x87, 0x6c, 0x35, 0xe7, 0xa8, 0x4d, 0x35,
	0xeb, 0xc1, 0x41, 0xaa, 0x8a, 0xd2, 0xda, 0x19,
	0xaa, 0x79, 0xa2, 0x5f, 0x35, 0x2c, 0xa0, 0xfd,
	0x25, 0xd3, 0xf7, 0x9d, 0x25, 0x18, 0x2d, 0xfa,
	0xb4, 0xbc, 0xbb, 0x07, 0x34, 0x3c, 0x8d, 0x81,
	0xbd, 0xf4, 0xe9, 0x37, 0xdb, 0x39, 0xe9, 0xd1,
	0x45, 0x5b, 0x20, 0x41, 0x2f, 0x2d, 0x27, 0x22,
	0xdc, 0x92, 0x74, 0x8a, 0x92, 0xd5, 0x83, 0xfd,
	0x09, 0xfb, 0x13, 0x9b, 0xe3, 0x39, 0x7a, 0x6b,
	0x5c, 0xfa, 0xe6, 0x76, 0x9e, 0xe0, 0xe4, 0xe3,
	0xef, 0xad, 0xbc, 0xfd, 0x42, 0x45, 0x9a, 0xd4,
	0x94, 0xd1, 0x7e, 0x8d, 0xa7, 0xd8, 0x05, 0xd5,
	0xd3, 0x62, 0xcf, 0x15, 0xcf, 0x94, 0x7d, 0x1f,
	0x5b, 0x58, 0x20, 0x44, 0x20, 0x90, 0x71, 0xbe,
	0x66, 0xe9, 0x9a, 0xab, 0x74, 0x32, 0x70, 0x53,
	0x1d, 0x69, 0xed, 0x87, 0x66, 0xf4, 0x09, 0x4f,
	0xca, 0x25, 0x30, 0xc2, 0x63, 0x79, 0x00, 0x3c,
	0xb1, 0x9b, 0x39, 0x3f, 0x00, 0xe0, 0xa8, 0x88,
	0xef, 0x7a, 0x51, 0x5b, 0xe7, 0xbd, 0x49, 0x64,
	0xda, 0x41, 0x7b, 0x24, 0xc3, 0x71, 0x22, 0xfd,
	0xd1, 0xd1, 0x20, 0xb3, 0x3f, 0x97, 0xd3, 0x97,
	0xb2, 0xaa, 0x18, 0x1c, 0x9e, 0x03, 0x77, 0x7b,
	0x5b, 0x7e, 0xf9, 0xa3, 0xa0, 0xd6, 0x20, 0x81,
	0x2c, 0x38, 0x8f, 0x9d, 0x25, 0xde, 0xe9, 0xc8,
	0xf5, 0xdd, 0x6a, 0x47, 0x9c, 0x65, 0x04, 0x5a,
	0x56, 0xe6, 0xc2, 0xeb, 0xf2, 0x02, 0x97, 0xe1,
	0xb9, 0xd8, 0xe1, 0x24, 0x76, 0x9f, 0x23, 0x62,
	0x39, 0x03, 0x4b, 0xc8, 0xf7, 0x34, 0x07, 0x49,
	0xd6, 0xe7, 0x4d, 0x9a, 0x68, 0x61, 0x75, 0x74,
	0x68, 0x44, 0x61, 0x74, 0x61, 0x58, 0xc4, 0x49,
	0x96, 0x0d, 0xe5, 0x88, 0x0e, 0x8c, 0x68, 0x74,
	0x34, 0x17, 0x0f, 0x64, 0x76, 0x60, 0x5b, 0x8f,
	0xe4, 0xae, 0xb9, 0xa2, 0x86, 0x32, 0xc7, 0x99,
	0x5c, 0xf3, 0xba, 0x83, 0x1d, 0x97, 0x63, 0x41,
	0x00, 0x00, 0x00, 0x00, 0xf8, 0xa0, 0x11, 0xf3,
	0x8c, 0x0a, 0x4d, 0x15, 0x80, 0x06, 0x17, 0x11,
	0x1f, 0x9e, 0xdc, 0x7d, 0x00, 0x40, 0x53, 0xfb,
	0xdf, 0xaa, 0xce, 0x63, 0xde, 0xc5, 0xfe, 0x47,
	0xe6, 0x52, 0xeb, 0xf3, 0x5d, 0x53, 0xa8, 0xbf,
	0x9d, 0xd6, 0x09, 0x6b, 0x5e, 0x7f, 0xe0, 0x0d,
	0x51, 0x30, 0x85, 0x6a, 0xda, 0x68, 0x70, 0x85,
	0xb0, 0xdb, 0x08, 0x0b, 0x83, 0x2c, 0xef, 0x44,
	0xe2, 0x36, 0x88, 0xee, 0x76, 0x90, 0x6e, 0x7b,
	0x50, 0x3e, 0x9a, 0xa0, 0xd6, 0x3c, 0x34, 0xe3,
	0x83, 0xe7, 0xd1, 0xbd, 0x9f, 0x25, 0xa5, 0x01,
	0x02, 0x03, 0x26, 0x20, 0x01, 0x21, 0x58, 0x20,
	0x17, 0x5b, 0x27, 0xa6, 0x56, 0xb2, 0x26, 0x0c,
	0x26, 0x0c, 0x55, 0x42, 0x78, 0x17, 0x5d, 0x4c,
	0xf8, 0xa2, 0xfd, 0x1b, 0xb9, 0x54, 0xdf, 0xd5,
	0xeb, 0xbf, 0x22, 0x64, 0xf5, 0x21, 0x9a, 0xc6,
	0x22, 0x58, 0x20, 0x87, 0x5f, 0x90, 0xe6, 0xfd,
	0x71, 0x27, 0x9f, 0xeb, 0xe3, 0x03, 0x44, 0xbc,
	0x8d, 0x49, 0xc6, 0x1c, 0x31, 0x3b, 0x72, 0xae,
	0xd4, 0x53, 0xb1, 0xfe, 0x5d, 0xe1, 0x30, 0xfc,
	0x2b, 0x1e, 0xd2
};

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->rp_id) < 0 ||
	    unpack_blob(v[2], &p->cdh) < 0 ||
	    unpack_blob(v[3], &p->attobj) < 0 ||
	    unpack_byte(v[4], &p->type) < 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(17)) == NULL ||
	    (argv[0] = pack_int(p->seed)) == NULL ||
	    (argv[1] = pack_string(p->rp_id)) == NULL ||
	    (argv[2] = pack_blob(&p->cdh)) == NULL ||
	    (argv[3] = pack_blob(&p->attobj)) == NULL ||
	    (argv[4] = pack_byte(p->type)) == 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));
	dummy.type = 1;

	strlcpy(dummy.rp_id, dummy_rp_id, sizeof(dummy.rp_id));

	dummy.cdh.len = sizeof(dummy_cdh);
	dummy.attobj.len = sizeof(dummy_attestation_object);

	memcpy(&dummy.cdh.body, &dummy_cdh, dummy.cdh.len);
	memcpy(&dummy.attobj.body, dummy_attestation_object, dummy.attobj.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;
}

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->type);
		p->attobj.len = sizeof(dummy_attestation_object);
		memcpy(&p->attobj.body, &dummy_attestation_object,
		    p->attobj.len);
		mutate_blob(&p->attobj);
	}
}

void
test(const struct param *p)
{
	fido_cred_t *cred = NULL;
	int r, cose_alg;

	prng_init((unsigned int)p->seed);
	fuzz_clock_reset();
	fido_init(FIDO_DEBUG);
	fido_set_log_handler(consume_str);

	if ((cred = fido_cred_new()) == NULL)
		return;

	switch (p->type & 3) {
	case 0:
		cose_alg = COSE_ES256;
		break;
	case 1:
		cose_alg = COSE_RS256;
		break;
	case 2:
		cose_alg = COSE_ES384;
		break;
	default:
		cose_alg = COSE_EDDSA;
		break;
	}

	r = fido_cred_set_type(cred, cose_alg);
	consume(&r, sizeof(r));
	r = fido_cred_set_rp(cred, p->rp_id, NULL);
	consume(&r, sizeof(r));
	r = fido_cred_set_clientdata_hash(cred, p->cdh.body, p->cdh.len);
	consume(&r, sizeof(r));
	r = fido_cred_set_attobj(cred, p->attobj.body, p->attobj.len);
	consume(&r, sizeof(r));

	consume_str(fido_cred_fmt(cred));
	consume(fido_cred_attstmt_ptr(cred), fido_cred_attstmt_len(cred));
	consume(fido_cred_authdata_ptr(cred), fido_cred_authdata_len(cred));
	r = fido_cred_verify(cred);
	consume(&r, sizeof(r));

	fido_cred_free(&cred);
}