transmission/libtransmission/crypto-utils-mbedtls.cc

250 lines
5.9 KiB
C++

// This file Copyright © Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <memory>
#include <mutex>
#include <mbedtls/base64.h>
#include <mbedtls/ctr_drbg.h>
#include <mbedtls/error.h>
#include <mbedtls/sha1.h>
#include <mbedtls/sha256.h>
#include <mbedtls/version.h>
#include <fmt/core.h>
#include "libtransmission/transmission.h"
#include "libtransmission/crypto-utils.h"
#include "libtransmission/log.h"
#include "libtransmission/tr-assert.h"
#include "libtransmission/utils.h"
#define TR_CRYPTO_X509_FALLBACK
#include "libtransmission/crypto-utils-fallback.cc" // NOLINT(bugprone-suspicious-include)
// ---
static void log_mbedtls_error(int error_code, char const* file, int line)
{
if (tr_logLevelIsActive(TR_LOG_ERROR))
{
char error_message[256];
mbedtls_strerror(error_code, error_message, sizeof(error_message));
tr_logAddMessage(
file,
line,
TR_LOG_ERROR,
fmt::format(
_("{crypto_library} error: {error} ({error_code})"),
fmt::arg("crypto_library", "MbedTLS"),
fmt::arg("error", error_message),
fmt::arg("error_code", error_code)));
}
}
#define log_error(error_code) log_mbedtls_error((error_code), __FILE__, __LINE__)
static bool check_mbedtls_result(int result, int expected_result, char const* file, int line)
{
bool const ret = result == expected_result;
if (!ret)
{
log_mbedtls_error(result, file, line);
}
return ret;
}
#define check_result(result) check_mbedtls_result((result), 0, __FILE__, __LINE__)
#define check_result_eq(result, x_result) check_mbedtls_result((result), (x_result), __FILE__, __LINE__)
// ---
static int my_rand(void* /*context*/, unsigned char* buffer, size_t buffer_size)
{
// since we're initializing tr_rand_buffer()'s rng, we can't use tr_rand_buffer() here
tr_rand_buffer_std(buffer, buffer_size);
return 0;
}
static mbedtls_ctr_drbg_context* get_rng()
{
static mbedtls_ctr_drbg_context rng;
static bool rng_initialized = false;
if (!rng_initialized)
{
#if MBEDTLS_VERSION_NUMBER >= 0x02000000
mbedtls_ctr_drbg_init(&rng);
if (!check_result(mbedtls_ctr_drbg_seed(&rng, my_rand, nullptr, nullptr, 0)))
#else
if (!check_result(mbedtls_ctr_drbg_init(&rng, my_rand, nullptr, nullptr, 0)))
#endif
{
return nullptr;
}
rng_initialized = true;
}
return &rng;
}
static std::recursive_mutex rng_mutex_;
// ---
namespace
{
class Sha1Impl final : public tr_sha1
{
public:
Sha1Impl()
{
clear();
}
~Sha1Impl() override = default;
void clear() override
{
mbedtls_sha1_init(&handle_);
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha1_starts_ret(&handle_);
#else
mbedtls_sha1_starts(&handle_);
#endif
}
void add(void const* data, size_t data_length) override
{
if (data_length > 0U)
{
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha1_update_ret(&handle_, static_cast<unsigned char const*>(data), data_length);
#else
mbedtls_sha1_update(&handle_, static_cast<unsigned char const*>(data), data_length);
#endif
}
}
[[nodiscard]] tr_sha1_digest_t finish() override
{
auto digest = tr_sha1_digest_t{};
auto* const digest_as_uchar = reinterpret_cast<unsigned char*>(std::data(digest));
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha1_finish_ret(&handle_, digest_as_uchar);
#else
mbedtls_sha1_finish(&handle_, digest_as_uchar);
#endif
mbedtls_sha1_free(&handle_);
return digest;
}
private:
mbedtls_sha1_context handle_ = {};
};
class Sha256Impl final : public tr_sha256
{
public:
Sha256Impl()
{
clear();
}
~Sha256Impl() override = default;
void clear() override
{
mbedtls_sha256_init(&handle_);
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha256_starts_ret(&handle_, 0);
#else
mbedtls_sha256_starts(&handle_);
#endif
}
void add(void const* data, size_t data_length) override
{
if (data_length > 0U)
{
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha256_update_ret(&handle_, static_cast<unsigned char const*>(data), data_length);
#else
mbedtls_sha256_update(&handle_, static_cast<unsigned char const*>(data), data_length);
#endif
}
}
[[nodiscard]] tr_sha256_digest_t finish() override
{
auto digest = tr_sha256_digest_t{};
auto* const digest_as_uchar = reinterpret_cast<unsigned char*>(std::data(digest));
#if MBEDTLS_VERSION_NUMBER >= 0x02070000
mbedtls_sha256_finish_ret(&handle_, digest_as_uchar);
#else
mbedtls_sha256_finish(&handle_, digest_as_uchar);
#endif
mbedtls_sha256_free(&handle_);
return digest;
}
private:
mbedtls_sha256_context handle_ = {};
};
} // namespace
std::unique_ptr<tr_sha1> tr_sha1::create()
{
return std::make_unique<Sha1Impl>();
}
std::unique_ptr<tr_sha256> tr_sha256::create()
{
return std::make_unique<Sha256Impl>();
}
// ---
bool tr_rand_buffer_crypto(void* buffer, size_t length)
{
if (length == 0)
{
return true;
}
TR_ASSERT(buffer != nullptr);
auto constexpr ChunkSize = size_t{ MBEDTLS_CTR_DRBG_MAX_REQUEST };
static_assert(ChunkSize > 0U);
auto const lock = std::lock_guard(rng_mutex_);
for (auto offset = size_t{ 0 }; offset < length; offset += ChunkSize)
{
if (!check_result(mbedtls_ctr_drbg_random(
get_rng(),
static_cast<unsigned char*>(buffer) + offset,
std::min(ChunkSize, length - offset))))
{
return false;
}
}
return true;
}