1ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales/* 2ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * Copyright 2015 The Android Open Source Project 3ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * 4ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * Licensed under the Apache License, Version 2.0 (the "License"); 5ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * you may not use this file except in compliance with the License. 6ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * You may obtain a copy of the License at 7ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * 8ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * http://www.apache.org/licenses/LICENSE-2.0 9ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * 10ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * Unless required by applicable law or agreed to in writing, software 11ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * distributed under the License is distributed on an "AS IS" BASIS, 12ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * See the License for the specific language governing permissions and 14ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * limitations under the License. 15ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * 16ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales */ 177d0f0406314df47b7502c3cd72dcefb83ead7132Andres Morales#ifndef GOOGLE_GATEKEEPER_UTILS_H_ 187d0f0406314df47b7502c3cd72dcefb83ead7132Andres Morales#define GOOGLE_GATEKEEPER_UTILS_H_ 19ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales 20ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#include <string.h> 21ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales 227d0f0406314df47b7502c3cd72dcefb83ead7132Andres Moralesnamespace gatekeeper { 23ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales/** 24ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * Variant of memset() that uses GCC-specific pragmas to disable optimizations, so effect is not 25ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * optimized away. This is important because we often need to wipe blocks of sensitive data from 26ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * memory. As an additional convenience, this implementation avoids writing to NULL pointers. 27ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales */ 28ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#ifdef __clang__ 29ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#define OPTNONE __attribute__((optnone)) 30ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#else // not __clang__ 31ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#define OPTNONE __attribute__((optimize("O0"))) 32ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#endif // not __clang__ 33ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Moralesinline OPTNONE void* memset_s(void* s, int c, size_t n) { 34ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales if (!s) 35ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales return s; 36ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales return memset(s, c, n); 37ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales} 38ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales#undef OPTNONE 39ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales 40ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales/** 41ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales * Return the number of elements in array \p a. 42ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales */ 43ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Moralestemplate <typename T, size_t N> inline size_t array_length(const T (&)[N]) { 44ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales return N; 45ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales} 46ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales 478aceb8fcd434ed95fb9b3d9bcfe2149a6adb1444Chih-Hung Hsiehstatic inline int memcmp_s(const void* p1, const void* p2, size_t length) { 48ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales const uint8_t* s1 = static_cast<const uint8_t*>(p1); 49ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales const uint8_t* s2 = static_cast<const uint8_t*>(p2); 50ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales uint8_t result = 0; 51ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales while (length-- > 0) 52ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales result |= *s1++ ^ *s2++; 53ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales return result == 0 ? 0 : 1; 54ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales} 55ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales 56ac80818fd9e477d142dd8ed2f3902ba3757855c9Andres Morales}; 577d0f0406314df47b7502c3cd72dcefb83ead7132Andres Morales#endif //GOOGLE_GATEKEEPER_UTILS_H_ 58