RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-28 04:27:45 +00:00
Code Issues Activity Actions

AK+Everywhere: Change AK::fill_with_random to accept a Bytes object

Browse source 
Rather than the very C-like API we currently have, accepting a void* and
a length, let's take a Bytes object instead. In almost all existing
cases, the compiler figures out the length.
This commit is contained in:
Timothy Flynn 2023-04-02 13:08:43 -04:00 • committed by Andreas Kling
parent 5c045b6934
commit 15532df83d
20 changed files with 37 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

23
AK/Random.h
View file

@ -7,6 +7,7 @@
#pragma once
#include <AK/Platform.h>
#include <AK/Span.h>
#include <AK/StdLibExtras.h>
#include <AK/Types.h>
#include <stdlib.h>
@ -21,36 +22,32 @@
namespace AK {
inline void fill_with_random([[maybe_unused]] void* buffer, [[maybe_unused]] size_t length)
inline void fill_with_random([[maybe_unused]] Bytes bytes)
{
#if defined(AK_OS_SERENITY) || defined(AK_OS_ANDROID)
arc4random_buf(buffer, length);
arc4random_buf(bytes.data(), bytes.size());
#elif defined(OSS_FUZZ)
#else
auto fill_with_random_fallback = [&]() {
char* char_buffer = static_cast<char*>(buffer);
for (size_t i = 0; i < length; i++)
char_buffer[i] = rand();
for (auto& byte : bytes)
byte = rand();
};
# if defined(__unix__) or defined(AK_OS_MACOS)
// The maximum permitted value for the getentropy length argument.
static constexpr size_t getentropy_length_limit = 256;
auto iterations = length / getentropy_length_limit;
auto remainder = length % getentropy_length_limit;
auto address = reinterpret_cast<FlatPtr>(buffer);
auto iterations = bytes.size() / getentropy_length_limit;
for (size_t i = 0; i < iterations; ++i) {
if (getentropy(reinterpret_cast<void*>(address), getentropy_length_limit) != 0) {
if (getentropy(bytes.data(), getentropy_length_limit) != 0) {
fill_with_random_fallback();
return;
}
address += getentropy_length_limit;
bytes = bytes.slice(getentropy_length_limit);
}
if (remainder == 0 || getentropy(reinterpret_cast<void*>(address), remainder) == 0)
if (bytes.is_empty() || getentropy(bytes.data(), bytes.size()) == 0)
return;
# endif
@ -62,7 +59,7 @@ template<typename T>
inline T get_random()
{
T t;
fill_with_random(&t, sizeof(T));
fill_with_random({ &t, sizeof(T) });
return t;
}