ladybird/Userland/Libraries/LibCore/SecretString.cpp
2023-02-08 19:49:48 +01:00

50 lines
1.4 KiB
C++

/*
* Copyright (c) 2021, Brian Gianforcaro <bgianf@serenityos.org>
* Copyright (c) 2021, Mustafa Quraish <mustafa@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Memory.h>
#include <LibCore/SecretString.h>
namespace Core {
ErrorOr<SecretString> SecretString::take_ownership(char*& cstring, size_t length)
{
auto buffer = TRY(ByteBuffer::copy(cstring, length));
secure_zero(cstring, length);
free(cstring);
cstring = nullptr;
return SecretString(move(buffer));
}
SecretString SecretString::take_ownership(ByteBuffer&& buffer)
{
return SecretString(move(buffer));
}
SecretString::SecretString(ByteBuffer&& buffer)
: m_secure_buffer(move(buffer))
{
// SecretString is currently only used to provide the character data to invocations to crypt(),
// which requires a NUL-terminated string. To ensure this operation avoids a buffer overrun,
// append a NUL terminator here if there isn't already one.
if (m_secure_buffer.is_empty() || (m_secure_buffer[m_secure_buffer.size() - 1] != 0)) {
u8 nul = '\0';
m_secure_buffer.append(&nul, 1);
}
}
SecretString::~SecretString()
{
// Note: We use secure_zero to avoid the zeroing from being optimized out by the compiler,
// which is possible if memset was to be used here.
if (!m_secure_buffer.is_empty()) {
secure_zero(m_secure_buffer.data(), m_secure_buffer.capacity());
}
}
}