| // Copyright 2010-2015, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
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| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| |
| #ifndef MOZC_BASE_UNVERIFIED_AES256_H_ |
| #define MOZC_BASE_UNVERIFIED_AES256_H_ |
| |
| #include "base/port.h" |
| |
| namespace mozc { |
| namespace internal { |
| |
| // Note that this implemenation is kept just for the backward compatibility |
| // so that we can read previously obfuscated data. |
| // !!! Not FIPS-certified. |
| // !!! Performance optimization is not well considered. |
| // !!! Side-channel attack is not well considered. |
| // TODO(team): Consider to remove this class and stop doing obfuscation. |
| class UnverifiedAES256 { |
| public: |
| static const size_t kKeyBytes = 32; // 256 bit |
| static const size_t kBlockBytes = 16; // 128 bit |
| static const size_t kKeyScheduleBytes = 240; |
| |
| // Does AES256 CBC transformation. |
| // CAVEATS: See the above comment. |
| static void TransformCBC(const uint8 (&key)[kKeyBytes], |
| const uint8 (&iv)[kBlockBytes], |
| uint8 *buffer, |
| size_t block_count); |
| |
| // Does AES256 CBC inverse transformation. |
| // CAVEATS: See the above comment. |
| static void InverseTransformCBC(const uint8 (&key)[kKeyBytes], |
| const uint8 (&iv)[kBlockBytes], |
| uint8 *buffer, |
| size_t block_count); |
| |
| protected: |
| // Does AES256 ECB transformation. |
| // CAVEATS: See the above comment. |
| static void TransformECB(const uint8 (&w)[kKeyScheduleBytes], |
| uint8 buffer[kBlockBytes]); |
| |
| // Does AES256 ECB inverse transformation. |
| // CAVEATS: See the above comment. |
| static void InverseTransformECB(const uint8 (&w)[kKeyScheduleBytes], |
| uint8 buffer[kBlockBytes]); |
| |
| // Declared as protected for unit test. |
| static void MakeKeySchedule(const uint8 (&key)[kKeyBytes], |
| uint8 w[kKeyScheduleBytes]); |
| static void SubBytes(uint8 buf[kBlockBytes]); |
| static void InvSubBytes(uint8 buf[kBlockBytes]); |
| static void MixColumns(uint8 buf[kBlockBytes]); |
| static void InvMixColumns(uint8 buf[kBlockBytes]); |
| static void ShiftRows(uint8 buf[kBlockBytes]); |
| static void InvShiftRows(uint8 buf[kBlockBytes]); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(UnverifiedAES256); |
| }; |
| |
| } // namespace internal |
| } // namespace mozc |
| |
| #endif // MOZC_BASE_UNVERIFIED_AES256_H_ |