static int uuid_v5()

in tee_core.c [144:196]

• 41 lines of code
• 7 McCabe index (conditional complexity)

static int uuid_v5(uuid_t *uuid, const uuid_t *ns, const void *name,
		   size_t size)
{
	unsigned char hash[SHA1_DIGEST_SIZE];
	struct crypto_shash *shash = NULL;
	struct shash_desc *desc = NULL;
	int rc;

	shash = crypto_alloc_shash("sha1", 0, 0);
	if (IS_ERR(shash)) {
		rc = PTR_ERR(shash);
		pr_err("shash(sha1) allocation failed\n");
		return rc;
	}

	desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash),
		       GFP_KERNEL);
	if (!desc) {
		rc = -ENOMEM;
		goto out_free_shash;
	}

	desc->tfm = shash;

	rc = crypto_shash_init(desc);
	if (rc < 0)
		goto out_free_desc;

	rc = crypto_shash_update(desc, (const u8 *)ns, sizeof(*ns));
	if (rc < 0)
		goto out_free_desc;

	rc = crypto_shash_update(desc, (const u8 *)name, size);
	if (rc < 0)
		goto out_free_desc;

	rc = crypto_shash_final(desc, hash);
	if (rc < 0)
		goto out_free_desc;

	memcpy(uuid->b, hash, UUID_SIZE);

	/* Tag for version 5 */
	uuid->b[6] = (hash[6] & 0x0F) | 0x50;
	uuid->b[8] = (hash[8] & 0x3F) | 0x80;

out_free_desc:
	kfree(desc);

out_free_shash:
	crypto_free_shash(shash);
	return rc;
}