diff --git a/Source/Core/DiscIO/VolumeWiiCrypted.cpp b/Source/Core/DiscIO/VolumeWiiCrypted.cpp index d956b9444d..57545eee01 100644 --- a/Source/Core/DiscIO/VolumeWiiCrypted.cpp +++ b/Source/Core/DiscIO/VolumeWiiCrypted.cpp @@ -47,7 +47,6 @@ bool CVolumeWiiCrypted::ChangePartition(u64 offset) return true; } - CVolumeWiiCrypted::~CVolumeWiiCrypted() { delete[] m_pBuffer; @@ -66,36 +65,41 @@ bool CVolumeWiiCrypted::Read(u64 _ReadOffset, u64 _Length, u8* _pBuffer, bool de while (_Length > 0) { - static unsigned char IV[16]; - - // math block offset + // Calculate block offset u64 Block = _ReadOffset / 0x7C00; u64 Offset = _ReadOffset % 0x7C00; - // read current block - if (!m_pReader->Read(m_VolumeOffset + m_dataOffset + Block * 0x8000, 0x8000, m_pBuffer)) - return(false); - if (m_LastDecryptedBlockOffset != Block) { - memcpy(IV, m_pBuffer + 0x3d0, 16); - aes_crypt_cbc(m_AES_ctx.get(), AES_DECRYPT, 0x7C00, IV, m_pBuffer + 0x400, m_LastDecryptedBlock); + // Read the current block + if (!m_pReader->Read(m_VolumeOffset + m_dataOffset + Block * 0x8000, 0x8000, m_pBuffer)) + return false; + // Decrypt the block's data. + // 0x3D0 - 0x3DF in m_pBuffer will be overwritten, + // but that won't affect anything, because we won't + // use the content of m_pBuffer anymore after this + aes_crypt_cbc(m_AES_ctx.get(), AES_DECRYPT, 0x7C00, m_pBuffer + 0x3D0, m_pBuffer + 0x400, m_LastDecryptedBlock); m_LastDecryptedBlockOffset = Block; + + // The only thing we currently use from the 0x000 - 0x3FF part + // of the block is the IV (at 0x3D0), but it also contains SHA-1 + // hashes that IOS uses to check that discs aren't tampered with. + // http://wiibrew.org/wiki/Wii_Disc#Encrypted } - // copy the encrypted data + // Copy the decrypted data u64 MaxSizeToCopy = 0x7C00 - Offset; u64 CopySize = (_Length > MaxSizeToCopy) ? MaxSizeToCopy : _Length; memcpy(_pBuffer, &m_LastDecryptedBlock[Offset], (size_t)CopySize); - // increase buffers + // Update offsets _Length -= CopySize; _pBuffer += CopySize; _ReadOffset += CopySize; } - return(true); + return true; } bool CVolumeWiiCrypted::GetTitleID(u8* _pBuffer) const diff --git a/Source/Core/DiscIO/VolumeWiiCrypted.h b/Source/Core/DiscIO/VolumeWiiCrypted.h index 1cca81c410..608964dc64 100644 --- a/Source/Core/DiscIO/VolumeWiiCrypted.h +++ b/Source/Core/DiscIO/VolumeWiiCrypted.h @@ -53,7 +53,7 @@ private: u64 m_dataOffset; mutable u64 m_LastDecryptedBlockOffset; - mutable unsigned char m_LastDecryptedBlock[0x8000]; + mutable unsigned char m_LastDecryptedBlock[0x7C00]; }; } // namespace