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Diffstat (limited to 'src/core/crypto/aes_util.cpp')
| -rw-r--r-- | src/core/crypto/aes_util.cpp | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/src/core/crypto/aes_util.cpp b/src/core/crypto/aes_util.cpp new file mode 100644 index 000000000..4690af5f8 --- /dev/null +++ b/src/core/crypto/aes_util.cpp @@ -0,0 +1,112 @@ +// Copyright 2018 yuzu emulator team +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include <mbedtls/cipher.h> +#include "core/crypto/aes_util.h" +#include "core/crypto/key_manager.h" + +namespace Core::Crypto { + +static_assert(static_cast<size_t>(Mode::CTR) == static_cast<size_t>(MBEDTLS_CIPHER_AES_128_CTR), + "CTR has incorrect value."); +static_assert(static_cast<size_t>(Mode::ECB) == static_cast<size_t>(MBEDTLS_CIPHER_AES_128_ECB), + "ECB has incorrect value."); +static_assert(static_cast<size_t>(Mode::XTS) == static_cast<size_t>(MBEDTLS_CIPHER_AES_128_XTS), + "XTS has incorrect value."); + +// Structure to hide mbedtls types from header file +struct CipherContext { + mbedtls_cipher_context_t encryption_context; + mbedtls_cipher_context_t decryption_context; +}; + +template <typename Key, size_t KeySize> +Crypto::AESCipher<Key, KeySize>::AESCipher(Key key, Mode mode) + : ctx(std::make_unique<CipherContext>()) { + mbedtls_cipher_init(&ctx->encryption_context); + mbedtls_cipher_init(&ctx->decryption_context); + + ASSERT_MSG((mbedtls_cipher_setup( + &ctx->encryption_context, + mbedtls_cipher_info_from_type(static_cast<mbedtls_cipher_type_t>(mode))) || + mbedtls_cipher_setup( + &ctx->decryption_context, + mbedtls_cipher_info_from_type(static_cast<mbedtls_cipher_type_t>(mode)))) == 0, + "Failed to initialize mbedtls ciphers."); + + ASSERT( + !mbedtls_cipher_setkey(&ctx->encryption_context, key.data(), KeySize * 8, MBEDTLS_ENCRYPT)); + ASSERT( + !mbedtls_cipher_setkey(&ctx->decryption_context, key.data(), KeySize * 8, MBEDTLS_DECRYPT)); + //"Failed to set key on mbedtls ciphers."); +} + +template <typename Key, size_t KeySize> +AESCipher<Key, KeySize>::~AESCipher() { + mbedtls_cipher_free(&ctx->encryption_context); + mbedtls_cipher_free(&ctx->decryption_context); +} + +template <typename Key, size_t KeySize> +void AESCipher<Key, KeySize>::SetIV(std::vector<u8> iv) { + ASSERT_MSG((mbedtls_cipher_set_iv(&ctx->encryption_context, iv.data(), iv.size()) || + mbedtls_cipher_set_iv(&ctx->decryption_context, iv.data(), iv.size())) == 0, + "Failed to set IV on mbedtls ciphers."); +} + +template <typename Key, size_t KeySize> +void AESCipher<Key, KeySize>::Transcode(const u8* src, size_t size, u8* dest, Op op) { + size_t written = 0; + + const auto context = op == Op::Encrypt ? &ctx->encryption_context : &ctx->decryption_context; + + mbedtls_cipher_reset(context); + + if (mbedtls_cipher_get_cipher_mode(context) == MBEDTLS_MODE_XTS) { + mbedtls_cipher_update(context, src, size, dest, &written); + if (written != size) + LOG_WARNING(Crypto, "Not all data was decrypted requested={:016X}, actual={:016X}.", + size, written); + } else { + const auto block_size = mbedtls_cipher_get_block_size(context); + + for (size_t offset = 0; offset < size; offset += block_size) { + auto length = std::min<size_t>(block_size, size - offset); + mbedtls_cipher_update(context, src + offset, length, dest + offset, &written); + if (written != length) + LOG_WARNING(Crypto, "Not all data was decrypted requested={:016X}, actual={:016X}.", + length, written); + } + } + + mbedtls_cipher_finish(context, nullptr, nullptr); +} + +template <typename Key, size_t KeySize> +void AESCipher<Key, KeySize>::XTSTranscode(const u8* src, size_t size, u8* dest, size_t sector_id, + size_t sector_size, Op op) { + if (size % sector_size > 0) { + LOG_CRITICAL(Crypto, "Data size must be a multiple of sector size."); + return; + } + + for (size_t i = 0; i < size; i += sector_size) { + SetIV(CalculateNintendoTweak(sector_id++)); + Transcode<u8, u8>(src + i, sector_size, dest + i, op); + } +} + +template <typename Key, size_t KeySize> +std::vector<u8> AESCipher<Key, KeySize>::CalculateNintendoTweak(size_t sector_id) { + std::vector<u8> out(0x10); + for (size_t i = 0xF; i <= 0xF; --i) { + out[i] = sector_id & 0xFF; + sector_id >>= 8; + } + return out; +} + +template class AESCipher<Key128>; +template class AESCipher<Key256>; +} // namespace Core::Crypto
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