forked from dolphin-emu/dolphin
fff1db9730
This makes it easier to generate random numbers or fill a buffer with random data in a cryptographically secure way. This also replaces existing usages of RNG functions in the codebase: * <random> is pretty hard to use correctly, and std::random_device does not give enough guarantees about its results (it's implementation-defined, non cryptographically secure and could be deterministic on some platforms). Doing things correctly is error prone and verbose. * rand() is terrible and should not be used especially in crypto code.
50 lines
1.1 KiB
C++
50 lines
1.1 KiB
C++
// Copyright 2018 Dolphin Emulator Project
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// Licensed under GPLv2+
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// Refer to the license.txt file included.
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#include "Common/Random.h"
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#include <mbedtls/entropy.h>
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#include <mbedtls/hmac_drbg.h>
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#include "Common/Assert.h"
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namespace Common::Random
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{
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class CSPRNG final
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{
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public:
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CSPRNG()
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{
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mbedtls_entropy_init(&m_entropy);
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mbedtls_hmac_drbg_init(&m_context);
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const int ret = mbedtls_hmac_drbg_seed(&m_context, mbedtls_md_info_from_type(MBEDTLS_MD_SHA256),
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mbedtls_entropy_func, &m_entropy, nullptr, 0);
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ASSERT(ret == 0);
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}
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~CSPRNG()
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{
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mbedtls_hmac_drbg_free(&m_context);
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mbedtls_entropy_free(&m_entropy);
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}
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void Generate(void* buffer, std::size_t size)
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{
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const int ret = mbedtls_hmac_drbg_random(&m_context, static_cast<u8*>(buffer), size);
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ASSERT(ret == 0);
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}
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private:
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mbedtls_entropy_context m_entropy;
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mbedtls_hmac_drbg_context m_context;
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};
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static thread_local CSPRNG s_csprng;
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void Generate(void* buffer, std::size_t size)
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{
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s_csprng.Generate(buffer, size);
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}
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} // namespace Common::Random
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