programs/test_compute_digest.c - pub/scm/fs/fsverity/fsverity-utils - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Test libfsverity_compute_digest().
  *
  * Copyright 2020 Google LLC
  */

 #include "utils.h"

 #include <ctype.h>
 #include <inttypes.h>

 struct mem_file {
 	u8 *data;
 	size_t size;
 	size_t offset;
 };

 static int read_fn(void *fd, void *buf, size_t count)
 {
 	struct mem_file *f = fd;

 	ASSERT(count <= f->size - f->offset);
 	memcpy(buf, &f->data[f->offset], count);
 	f->offset += count;
 	return 0;
 }

 static int error_read_fn(void *fd __attribute__((unused)),
 			 void *buf __attribute__((unused)),
 			 size_t count __attribute__((unused)))
 {
 	return -EIO;
 }

 static const struct test_case {
 	u32 hash_algorithm;
 	u32 block_size;
 	const char *salt;
 	u64 file_size;
 	const char *digest;
 } test_cases[] = {
 	{ /* large file */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 4096,
 		.digest = "\x48\xdf\x0c\x46\x23\x29\xcd\x87"
 			  "\x96\x61\xbd\x05\xb3\x9a\xa8\x1b"
 			  "\x05\xcc\x16\xaf\xd2\x7a\x71\x96"
 			  "\xa5\x59\xda\x83\x53\x1d\x39\xd9",
 	}, { /* small file */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 100000,
 		.block_size = 4096,
 		.digest = "\xf2\x09\x6a\x36\xc5\xcd\xca\x4f"
 			  "\xa3\x3e\xe8\x85\x28\x33\x15\x0b"
 			  "\xb3\x24\x99\x2e\x54\x17\xa9\xd5"
 			  "\x71\xf1\xbf\xff\xf7\x3b\x9e\xfc",
 	}, { /* single-block file */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 4096,
 		.block_size = 4096,
 		.digest = "\x6a\xc3\x99\x79\x01\x6e\x3d\xdf"
 			  "\x3d\x39\xff\xf6\xcb\x98\x4f\x7c"
 			  "\x11\x8a\xcd\xf1\x85\x29\x19\xf5"
 			  "\xc1\x00\xc4\xb1\x42\xc1\x81\x8e",
 	}, { /* tiny file */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1,
 		.block_size = 4096,
 		.digest = "\xb8\x03\x42\x95\x03\xd9\x59\x15"
 			  "\x82\x9b\x29\xfd\xbc\x8b\xba\xd1"
 			  "\x42\xf3\xab\xfd\x11\xb1\xca\xdf"
 			  "\x55\x26\x58\x2e\x68\x5c\x05\x51",
 	}, { /* empty file */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 0,
 		.block_size = 4096,
 		.digest = "\x3d\x24\x8c\xa5\x42\xa2\x4f\xc6"
 			  "\x2d\x1c\x43\xb9\x16\xea\xe5\x01"
 			  "\x68\x78\xe2\x53\x3c\x88\x23\x84"
 			  "\x80\xb2\x61\x28\xa1\xf1\xaf\x95",
 	}, { /* salt */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 4096,
 		.salt = "abcd",
 		.digest = "\x91\x79\x00\xb0\xd2\x99\x45\x4a"
 			  "\xa3\x04\xd5\xde\xbc\x6f\x39\xe4"
 			  "\xaf\x7b\x5a\xbe\x33\xbd\xbc\x56"
 			  "\x8d\x5d\x8f\x1e\x5c\x4d\x86\x52",
 	}, { /* max length salt (32 bytes) */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 4096,
 		.salt = "0123456789:;<=>?@ABCDEFGHIJKLMNO",
 		.digest = "\xbc\x2d\x70\x32\x4c\x04\x8c\x22"
 			  "\x0a\x2c\xb1\x90\x83\x21\x40\x86"
 			  "\x3e\xb2\x68\xe6\x80\x42\x79\x39"
 			  "\xe5\xd4\x67\xbe\xa5\xec\x5a\xd9",
 	}, { /* 1K block size */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 1024,
 		.digest = "\xe9\xdf\x92\x7c\x14\xfc\xb9\x61"
 			  "\xd5\xf5\x1c\x66\x6d\x8a\xe4\xc1"
 			  "\x4f\xe4\xff\x98\xa3\x74\xc7\x33"
 			  "\xe8\x98\xd0\x0c\x9e\x74\xa8\xe3",
 	}, { /* 512-byte block size */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 512,
 		.digest = "\x03\x93\xee\x3d\xfd\x4a\x28\x96"
 			  "\x6e\x2a\xf4\xe0\x7c\xfa\x5b\x03"
 			  "\x2c\x30\xda\x5b\xb8\xe8\xef\x63"
 			  "\xb9\xa5\x5b\xf9\x63\x26\x23\x34",
 	}, { /* 64K block size */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 1000000,
 		.block_size = 65536,
 		.digest = "\xf3\xb6\x41\x8f\x26\xd4\xd0\xe7"
 			  "\x47\x28\x19\x3b\xae\x76\xf1\x5c"
 			  "\xb4\xbb\x2c\xe9\x77\x74\x48\xd7"
 			  "\x6b\xd8\x13\x8b\x69\xec\x61\xc2",
 	}, { /* SHA-512 */
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA512,
 		.file_size = 1000000,
 		.block_size = 4096,
 		.salt = "abcd",
 		.digest = "\x84\x25\xc6\xd0\xc9\x4f\x84\xed"
 			  "\x90\x4c\x12\x93\x68\x45\xfb\xb7"
 			  "\xaf\x99\x53\x75\x37\x89\x71\x2d"
 			  "\xcc\x3b\xe1\x42\xdb\x3d\x4b\x6b"
 			  "\x47\xa3\x99\xad\x52\xaa\x60\x92"
 			  "\x56\xce\x29\xa9\x60\xbf\x4b\xb0"
 			  "\xe5\x95\xec\x38\x6c\xa5\x8c\x06"
 			  "\x51\x9d\x54\x6d\xc5\xb1\x97\xbb",
 	}
 };

 static void fix_digest_and_print(const struct test_case *t,
 				 const struct libfsverity_digest *d)
 {
 	char alg_name[32] = {};
 	size_t i;

 	strncpy(alg_name, libfsverity_get_hash_name(t->hash_algorithm),
 		sizeof(alg_name) - 1);
 	for (i = 0; i < sizeof(alg_name) - 1; i++)
 		alg_name[i] = toupper((u8)alg_name[i]);

 	printf("\t}, {\n"
 	       "\t\t.hash_algorithm = FS_VERITY_HASH_ALG_%s,\n"
 	       "\t\t.file_size = %" PRIu64 ",\n"
 	       "\t\t.block_size = %u,\n",
 	       alg_name, t->file_size, t->block_size);
 	if (t->salt != NULL)
 		printf("\t\t.salt = \"%s\",\n", t->salt);
 	for (i = 0; i < d->digest_size; i++) {
 		if (i == 0)
 			printf("\t\t.digest = \"");
 		else if (i % 8 == 0)
 			printf("\t\t\t  \"");
 		printf("\\x%02x", d->digest[i]);
 		if (i + 1 == d->digest_size)
 			printf("\",\n");
 		else if (i % 8 == 7)
 			printf("\"\n");
 	}
 }

 static void test_invalid_params(void)
 {
 	struct mem_file f = { .data = (u8 *)"abcd", .size = 4 };
 	struct libfsverity_merkle_tree_params good_params = {
 		.version = 1,
 		.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
 		.file_size = 4,
 		.block_size = 4096,
 	};
 	struct libfsverity_merkle_tree_params params;
 	struct libfsverity_digest *d = NULL;

 	libfsverity_set_error_callback(NULL);

 	ASSERT(libfsverity_compute_digest(&f, read_fn, &good_params, &d) == 0);
 	f.offset = 0;
 	free(d);
 	d = NULL;

 	/* missing required arguments */
 	ASSERT(libfsverity_compute_digest(&f, NULL, &good_params, &d) == -EINVAL);
 	ASSERT(libfsverity_compute_digest(&f, read_fn, NULL, &d) == -EINVAL);
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &good_params, NULL) == -EINVAL);

 	/* bad version */
 	params = good_params;
 	params.version = 0;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params.version = 1000;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

 	/* bad hash_algorithm */
 	params = good_params;
 	params.hash_algorithm = 0;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params.hash_algorithm = 1000;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

 	/* bad block_size */
 	params = good_params;
 	params.block_size = 0;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params.block_size = 1;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params.block_size = 4097;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

 	/* bad salt_size */
 	params = good_params;
 	params.salt_size = 1000;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params.salt = (u8 *)"";
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

 	/* bad reserved fields */
 	params = good_params;
 	params.reserved1[0] = 1;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params = good_params;
 	params.reserved1[ARRAY_SIZE(params.reserved1) - 1] = 1;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params = good_params;
 	params.reserved2[0] = 1;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
 	params = good_params;
 	params.reserved2[ARRAY_SIZE(params.reserved2) - 1] = 1;
 	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

 	/* error reading file */
 	ASSERT(libfsverity_compute_digest(&f, error_read_fn, &good_params, &d) == -EIO);

 	ASSERT(d == NULL);
 }

 int main(int argc, char *argv[])
 {
 	const bool update = (argc == 2 && !strcmp(argv[1], "--update"));
 	size_t i;
 	struct mem_file f = {};
 	struct libfsverity_merkle_tree_params params;
 	struct libfsverity_digest *d;
 	int err;

 	install_libfsverity_error_handler();

 	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
 		f.size = max(f.size, test_cases[i].file_size);

 	f.data = xmalloc(f.size);
 	for (i = 0; i < f.size; i++)
 		f.data[i] = (i % 11) + (i % 439) + (i % 1103);

 	for (i = 0; i < ARRAY_SIZE(test_cases); i++) {

 		memset(&params, 0, sizeof(params));
 		params.version = 1;
 		params.hash_algorithm = test_cases[i].hash_algorithm;
 		params.file_size = test_cases[i].file_size;
 		params.block_size = test_cases[i].block_size;
 		if (test_cases[i].salt) {
 			params.salt = (const u8 *)test_cases[i].salt;
 			params.salt_size = strlen(test_cases[i].salt);
 		}

 		f.size = test_cases[i].file_size;
 		f.offset = 0;

 		err = libfsverity_compute_digest(&f, read_fn, &params, &d);
 		ASSERT(err == 0);

 		ASSERT(d->digest_algorithm == test_cases[i].hash_algorithm);
 		ASSERT(d->digest_size ==
 		       libfsverity_get_digest_size(test_cases[i].hash_algorithm));
 		if (update)
 			fix_digest_and_print(&test_cases[i], d);
 		else
 			ASSERT(!memcmp(d->digest, test_cases[i].digest,
 				       d->digest_size));
 		free(d);
 		d = NULL;
 	}
 	free(f.data);
 	if (update) {
 		printf("\t}\n");
 		return 1;
 	}

 	test_invalid_params();
 	printf("test_compute_digest passed\n");
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Test libfsverity_compute_digest().
	*
	* Copyright 2020 Google LLC
	*/

	#include "utils.h"

	#include <ctype.h>
	#include <inttypes.h>

	struct mem_file {
	u8 *data;
	size_t size;
	size_t offset;
	};

	static int read_fn(void fd, void buf, size_t count)
	{
	struct mem_file *f = fd;

	ASSERT(count <= f->size - f->offset);
	memcpy(buf, &f->data[f->offset], count);
	f->offset += count;
	return 0;
	}

	static int error_read_fn(void *fd __attribute__((unused)),
	void *buf __attribute__((unused)),
	size_t count __attribute__((unused)))
	{
	return -EIO;
	}

	static const struct test_case {
	u32 hash_algorithm;
	u32 block_size;
	const char *salt;
	u64 file_size;
	const char *digest;
	} test_cases[] = {
	{ /* large file */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 4096,
	.digest = "\x48\xdf\x0c\x46\x23\x29\xcd\x87"
	"\x96\x61\xbd\x05\xb3\x9a\xa8\x1b"
	"\x05\xcc\x16\xaf\xd2\x7a\x71\x96"
	"\xa5\x59\xda\x83\x53\x1d\x39\xd9",
	}, { /* small file */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 100000,
	.block_size = 4096,
	.digest = "\xf2\x09\x6a\x36\xc5\xcd\xca\x4f"
	"\xa3\x3e\xe8\x85\x28\x33\x15\x0b"
	"\xb3\x24\x99\x2e\x54\x17\xa9\xd5"
	"\x71\xf1\xbf\xff\xf7\x3b\x9e\xfc",
	}, { /* single-block file */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 4096,
	.block_size = 4096,
	.digest = "\x6a\xc3\x99\x79\x01\x6e\x3d\xdf"
	"\x3d\x39\xff\xf6\xcb\x98\x4f\x7c"
	"\x11\x8a\xcd\xf1\x85\x29\x19\xf5"
	"\xc1\x00\xc4\xb1\x42\xc1\x81\x8e",
	}, { /* tiny file */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1,
	.block_size = 4096,
	.digest = "\xb8\x03\x42\x95\x03\xd9\x59\x15"
	"\x82\x9b\x29\xfd\xbc\x8b\xba\xd1"
	"\x42\xf3\xab\xfd\x11\xb1\xca\xdf"
	"\x55\x26\x58\x2e\x68\x5c\x05\x51",
	}, { /* empty file */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 0,
	.block_size = 4096,
	.digest = "\x3d\x24\x8c\xa5\x42\xa2\x4f\xc6"
	"\x2d\x1c\x43\xb9\x16\xea\xe5\x01"
	"\x68\x78\xe2\x53\x3c\x88\x23\x84"
	"\x80\xb2\x61\x28\xa1\xf1\xaf\x95",
	}, { /* salt */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 4096,
	.salt = "abcd",
	.digest = "\x91\x79\x00\xb0\xd2\x99\x45\x4a"
	"\xa3\x04\xd5\xde\xbc\x6f\x39\xe4"
	"\xaf\x7b\x5a\xbe\x33\xbd\xbc\x56"
	"\x8d\x5d\x8f\x1e\x5c\x4d\x86\x52",
	}, { /* max length salt (32 bytes) */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 4096,
	.salt = "0123456789:;<=>?@ABCDEFGHIJKLMNO",
	.digest = "\xbc\x2d\x70\x32\x4c\x04\x8c\x22"
	"\x0a\x2c\xb1\x90\x83\x21\x40\x86"
	"\x3e\xb2\x68\xe6\x80\x42\x79\x39"
	"\xe5\xd4\x67\xbe\xa5\xec\x5a\xd9",
	}, { /* 1K block size */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 1024,
	.digest = "\xe9\xdf\x92\x7c\x14\xfc\xb9\x61"
	"\xd5\xf5\x1c\x66\x6d\x8a\xe4\xc1"
	"\x4f\xe4\xff\x98\xa3\x74\xc7\x33"
	"\xe8\x98\xd0\x0c\x9e\x74\xa8\xe3",
	}, { /* 512-byte block size */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 512,
	.digest = "\x03\x93\xee\x3d\xfd\x4a\x28\x96"
	"\x6e\x2a\xf4\xe0\x7c\xfa\x5b\x03"
	"\x2c\x30\xda\x5b\xb8\xe8\xef\x63"
	"\xb9\xa5\x5b\xf9\x63\x26\x23\x34",
	}, { /* 64K block size */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 1000000,
	.block_size = 65536,
	.digest = "\xf3\xb6\x41\x8f\x26\xd4\xd0\xe7"
	"\x47\x28\x19\x3b\xae\x76\xf1\x5c"
	"\xb4\xbb\x2c\xe9\x77\x74\x48\xd7"
	"\x6b\xd8\x13\x8b\x69\xec\x61\xc2",
	}, { /* SHA-512 */
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA512,
	.file_size = 1000000,
	.block_size = 4096,
	.salt = "abcd",
	.digest = "\x84\x25\xc6\xd0\xc9\x4f\x84\xed"
	"\x90\x4c\x12\x93\x68\x45\xfb\xb7"
	"\xaf\x99\x53\x75\x37\x89\x71\x2d"
	"\xcc\x3b\xe1\x42\xdb\x3d\x4b\x6b"
	"\x47\xa3\x99\xad\x52\xaa\x60\x92"
	"\x56\xce\x29\xa9\x60\xbf\x4b\xb0"
	"\xe5\x95\xec\x38\x6c\xa5\x8c\x06"
	"\x51\x9d\x54\x6d\xc5\xb1\x97\xbb",
	}
	};

	static void fix_digest_and_print(const struct test_case *t,
	const struct libfsverity_digest *d)
	{
	char alg_name[32] = {};
	size_t i;

	strncpy(alg_name, libfsverity_get_hash_name(t->hash_algorithm),
	sizeof(alg_name) - 1);
	for (i = 0; i < sizeof(alg_name) - 1; i++)
	alg_name[i] = toupper((u8)alg_name[i]);

	printf("\t}, {\n"
	"\t\t.hash_algorithm = FS_VERITY_HASH_ALG_%s,\n"
	"\t\t.file_size = %" PRIu64 ",\n"
	"\t\t.block_size = %u,\n",
	alg_name, t->file_size, t->block_size);
	if (t->salt != NULL)
	printf("\t\t.salt = \"%s\",\n", t->salt);
	for (i = 0; i < d->digest_size; i++) {
	if (i == 0)
	printf("\t\t.digest = \"");
	else if (i % 8 == 0)
	printf("\t\t\t \"");
	printf("\\x%02x", d->digest[i]);
	if (i + 1 == d->digest_size)
	printf("\",\n");
	else if (i % 8 == 7)
	printf("\"\n");
	}
	}

	static void test_invalid_params(void)
	{
	struct mem_file f = { .data = (u8 *)"abcd", .size = 4 };
	struct libfsverity_merkle_tree_params good_params = {
	.version = 1,
	.hash_algorithm = FS_VERITY_HASH_ALG_SHA256,
	.file_size = 4,
	.block_size = 4096,
	};
	struct libfsverity_merkle_tree_params params;
	struct libfsverity_digest *d = NULL;

	libfsverity_set_error_callback(NULL);

	ASSERT(libfsverity_compute_digest(&f, read_fn, &good_params, &d) == 0);
	f.offset = 0;
	free(d);
	d = NULL;

	/* missing required arguments */
	ASSERT(libfsverity_compute_digest(&f, NULL, &good_params, &d) == -EINVAL);
	ASSERT(libfsverity_compute_digest(&f, read_fn, NULL, &d) == -EINVAL);
	ASSERT(libfsverity_compute_digest(&f, read_fn, &good_params, NULL) == -EINVAL);

	/* bad version */
	params = good_params;
	params.version = 0;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params.version = 1000;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

	/* bad hash_algorithm */
	params = good_params;
	params.hash_algorithm = 0;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params.hash_algorithm = 1000;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

	/* bad block_size */
	params = good_params;
	params.block_size = 0;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params.block_size = 1;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params.block_size = 4097;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

	/* bad salt_size */
	params = good_params;
	params.salt_size = 1000;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params.salt = (u8 *)"";
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

	/* bad reserved fields */
	params = good_params;
	params.reserved1[0] = 1;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params = good_params;
	params.reserved1[ARRAY_SIZE(params.reserved1) - 1] = 1;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params = good_params;
	params.reserved2[0] = 1;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);
	params = good_params;
	params.reserved2[ARRAY_SIZE(params.reserved2) - 1] = 1;
	ASSERT(libfsverity_compute_digest(&f, read_fn, &params, &d) == -EINVAL);

	/* error reading file */
	ASSERT(libfsverity_compute_digest(&f, error_read_fn, &good_params, &d) == -EIO);

	ASSERT(d == NULL);
	}

	int main(int argc, char *argv[])
	{
	const bool update = (argc == 2 && !strcmp(argv[1], "--update"));
	size_t i;
	struct mem_file f = {};
	struct libfsverity_merkle_tree_params params;
	struct libfsverity_digest *d;
	int err;

	install_libfsverity_error_handler();

	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
	f.size = max(f.size, test_cases[i].file_size);

	f.data = xmalloc(f.size);
	for (i = 0; i < f.size; i++)
	f.data[i] = (i % 11) + (i % 439) + (i % 1103);

	for (i = 0; i < ARRAY_SIZE(test_cases); i++) {

	memset(&params, 0, sizeof(params));
	params.version = 1;
	params.hash_algorithm = test_cases[i].hash_algorithm;
	params.file_size = test_cases[i].file_size;
	params.block_size = test_cases[i].block_size;
	if (test_cases[i].salt) {
	params.salt = (const u8 *)test_cases[i].salt;
	params.salt_size = strlen(test_cases[i].salt);
	}

	f.size = test_cases[i].file_size;
	f.offset = 0;

	err = libfsverity_compute_digest(&f, read_fn, &params, &d);
	ASSERT(err == 0);

	ASSERT(d->digest_algorithm == test_cases[i].hash_algorithm);
	ASSERT(d->digest_size ==
	libfsverity_get_digest_size(test_cases[i].hash_algorithm));
	if (update)
	fix_digest_and_print(&test_cases[i], d);
	else
	ASSERT(!memcmp(d->digest, test_cases[i].digest,
	d->digest_size));
	free(d);
	d = NULL;
	}
	free(f.data);
	if (update) {
	printf("\t}\n");
	return 1;
	}

	test_invalid_params();
	printf("test_compute_digest passed\n");
	return 0;
	}