mirror/dolphin
1
0
Fork 0
mirror of https://github.com/dolphin-emu/dolphin.git synced 2025-02-28 16:11:38 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

GCMemcard: Rewrite Header::CalculateSerial() without undefined behavior.

Browse Source
This commit is contained in:
Admiral H. Curtiss 2019-05-05 00:59:38 +02:00
parent 6e04e4dd6a
commit fcd75841ca
2 changed files with 14 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
Source/Core/Core/HW/GCMemcard/GCMemcard.cpp
View File

@ -1306,7 +1306,6 @@ s32 GCMemcard::FZEROGX_MakeSaveGameValid(const Header& cardheader, const DEntry&
std::vector<GCMBlock>& FileBuffer) std::vector<GCMBlock>& FileBuffer)
{ {
u32 i, j; u32 i, j;
u32 serial1, serial2;
u16 chksum = 0xFFFF; u16 chksum = 0xFFFF;
// check for F-Zero GX system file // check for F-Zero GX system file
@ -1318,7 +1317,7 @@ s32 GCMemcard::FZEROGX_MakeSaveGameValid(const Header& cardheader, const DEntry&
return 0; return 0;
// get encrypted destination memory card serial numbers // get encrypted destination memory card serial numbers
cardheader.CalculateSerial(&serial1, &serial2); const auto [serial1, serial2] = cardheader.CalculateSerial();
// set new serial numbers // set new serial numbers
*(u16*)&FileBuffer[1].m_block[0x0066] = BE16(BE32(serial1) >> 16); *(u16*)&FileBuffer[1].m_block[0x0066] = BE16(BE32(serial1) >> 16);
@ -1364,7 +1363,6 @@ s32 GCMemcard::PSO_MakeSaveGameValid(const Header& cardheader, const DEntry& dir
u32 i, j; u32 i, j;
u32 chksum; u32 chksum;
u32 crc32LUT[256]; u32 crc32LUT[256];
u32 serial1, serial2;
u32 pso3offset = 0x00; u32 pso3offset = 0x00;
// check for PSO1&2 system file // check for PSO1&2 system file
@ -1384,7 +1382,7 @@ s32 GCMemcard::PSO_MakeSaveGameValid(const Header& cardheader, const DEntry& dir
} }
// get encrypted destination memory card serial numbers // get encrypted destination memory card serial numbers
cardheader.CalculateSerial(&serial1, &serial2); const auto [serial1, serial2] = cardheader.CalculateSerial();
// set new serial numbers // set new serial numbers
*(u32*)&FileBuffer[1].m_block[0x0158] = serial1; *(u32*)&FileBuffer[1].m_block[0x0158] = serial1;
@ -1457,17 +1455,22 @@ Header::Header(int slot, u16 size_mbits, bool shift_jis)
calc_checksumsBE((u16*)this, 0xFE, &m_checksum, &m_checksum_inv); calc_checksumsBE((u16*)this, 0xFE, &m_checksum, &m_checksum_inv);
} }
void Header::CalculateSerial(u32* serial1, u32* serial2) const std::pair<u32, u32> Header::CalculateSerial() const
{ {
u32 serial[8]; static_assert(std::is_trivially_copyable<Header>());
for (int i = 0; i < 8; i++) std::array<u8, 32> raw;
memcpy(raw.data(), this, raw.size());
u32 serial1 = 0;
u32 serial2 = 0;
for (size_t i = 0; i < raw.size(); i += 8)
{ {
memcpy(&serial[i], (u8*)this + (i * 4), 4); serial1 ^= Common::BitCastPtr<u32>(&raw[i + 0]);
serial2 ^= Common::BitCastPtr<u32>(&raw[i + 4]);
} }
*serial1 = serial[0] ^ serial[2] ^ serial[4] ^ serial[6]; return std::make_pair(serial1, serial2);
*serial2 = serial[1] ^ serial[3] ^ serial[5] ^ serial[7];
} }
DEntry::DEntry() DEntry::DEntry()

2
Source/Core/Core/HW/GCMemcard/GCMemcard.h
View File

@ -148,7 +148,7 @@ struct Header
explicit Header(int slot = 0, u16 size_mbits = MemCard2043Mb, bool shift_jis = false); explicit Header(int slot = 0, u16 size_mbits = MemCard2043Mb, bool shift_jis = false);
// Calculates the card serial numbers used for encrypting some save files. // Calculates the card serial numbers used for encrypting some save files.
void CalculateSerial(u32* serial1, u32* serial2) const; std::pair<u32, u32> CalculateSerial() const;
}; };
static_assert(sizeof(Header) == BLOCK_SIZE); static_assert(sizeof(Header) == BLOCK_SIZE);