FileSys/cia: add ticket parsing

src/core/file_sys/ticket.cpp

@@ -0,0 +1,56 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cryptopp/aes.h>
+#include <cryptopp/modes.h>
+#include "common/alignment.h"
+#include "core/file_sys/cia_common.h"
+#include "core/file_sys/ticket.h"
+#include "core/hw/aes/key.h"
+#include "core/loader/loader.h"
+
+namespace FileSys {
+
+Loader::ResultStatus Ticket::Load(const std::vector<u8> file_data, std::size_t offset) {
+    std::size_t total_size = static_cast<std::size_t>(file_data.size() - offset);
+    if (total_size < sizeof(u32))
+        return Loader::ResultStatus::Error;
+
+    std::memcpy(&signature_type, &file_data[offset], sizeof(u32));
+
+    // Signature lengths are variable, and the body follows the signature
+    u32 signature_size = GetSignatureSize(signature_type);
+
+    // The ticket body start position is rounded to the nearest 0x40 after the signature
+    std::size_t body_start = Common::AlignUp(signature_size + sizeof(u32), 0x40);
+    std::size_t body_end = body_start + sizeof(Body);
+
+    if (total_size < body_end)
+        return Loader::ResultStatus::Error;
+
+    // Read signature + ticket body
+    ticket_signature.resize(signature_size);
+    memcpy(ticket_signature.data(), &file_data[offset + sizeof(u32)], signature_size);
+    memcpy(&ticket_body, &file_data[offset + body_start], sizeof(Body));
+
+    return Loader::ResultStatus::Success;
+}
+
+boost::optional<std::array<u8, 16>> Ticket::GetTitleKey() const {
+    HW::AES::InitKeys();
+    std::array<u8, 16> ctr{};
+    std::memcpy(ctr.data(), &ticket_body.title_id, sizeof(u64));
+    HW::AES::SelectCommonKeyIndex(ticket_body.common_key_index);
+    if (!HW::AES::IsNormalKeyAvailable(HW::AES::KeySlotID::TicketCommonKey)) {
+        return boost::none;
+    }
+    auto key = HW::AES::GetNormalKey(HW::AES::KeySlotID::TicketCommonKey);
+    auto title_key = ticket_body.title_key;
+    CryptoPP::CBC_Mode<CryptoPP::AES>::Decryption{key.data(), key.size(), ctr.data()}.ProcessData(
+        title_key.data(), title_key.data(), title_key.size());
+    return title_key;
+}
+
+} // namespace FileSys