view padding.c @ 742:337fad78b8ae

base64: use a less complicated validity check in the decode loop Checking each of the four input chars for validity generates horrible machine code with many comparisons and conditional jumps. We can reduce this to just one comparison and one conditional jump by making assumptions about what invalid inputs look like (i.e., 0xff). Suggested by Timo Sirainen. Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
author Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
date Wed, 29 May 2019 10:58:19 -0400
parents 449d56767f49
children
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/*
 * Copyright (c) 2016 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <jeffpc/padding.h>

bool check_padding(const void *ptr, uint8_t byte, size_t size)
{
	const uint8_t *tmp = ptr;
	size_t i;

	for (i = 0; i < size; i++)
		if (tmp[i] != byte)
			return false;

	return true;
}