Load RSA slot_0 data from bootrom; load and decrypt data from native firm for NCCHSecure2 keyslot

src/core/hw/rsa/rsa.cpp

@@ -0,0 +1,102 @@
+// Copyright 2020 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <sstream>
+#include <cryptopp/integer.h>
+#include <cryptopp/nbtheory.h>
+#include <cryptopp/sha.h>
+#include <fmt/format.h>
+#include "common/common_paths.h"
+#include "common/file_util.h"
+#include "common/logging/log.h"
+#include "common/string_util.h"
+#include "core/hw/rsa/rsa.h"
+
+namespace HW::RSA {
+
+namespace {
+std::vector<u8> HexToBytes(const std::string& hex) {
+    std::vector<u8> bytes;
+
+    for (unsigned int i = 0; i < hex.length(); i += 2) {
+        std::string byteString = hex.substr(i, 2);
+        u8 byte = (u8)strtol(byteString.c_str(), NULL, 16);
+        bytes.push_back(byte);
+    }
+    return bytes;
+};
+} // namespace
+
+constexpr std::size_t SlotSize = 4;
+std::array<RsaSlot, SlotSize> rsa_slots;
+
+std::vector<u8> RsaSlot::GetSignature(const std::vector<u8>& message) {
+    CryptoPP::Integer sig =
+        CryptoPP::ModularExponentiation(CryptoPP::Integer(message.data(), message.size()),
+                                        CryptoPP::Integer(exponent.data(), exponent.size()),
+                                        CryptoPP::Integer(modulus.data(), modulus.size()));
+    std::stringstream ss;
+    ss << std::hex << sig;
+    return HexToBytes(ss.str());
+}
+
+void InitSlots() {
+    static bool initialized = false;
+    if (initialized)
+        return;
+    initialized = true;
+
+    const std::string filepath = FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) + BOOTROM9;
+    auto file = FileUtil::IOFile(filepath, "rb");
+    if (!file) {
+        return;
+    }
+
+    const std::size_t length = file.GetSize();
+    if (length != 65536) {
+        LOG_ERROR(HW_AES, "Bootrom9 size is wrong: {}", length);
+        return;
+    }
+
+    constexpr std::size_t RSA_MODULUS_POS = 0xB3E0;
+    file.Seek(RSA_MODULUS_POS, SEEK_SET);
+    std::vector<u8> modulus;
+    modulus.resize(256);
+    file.ReadArray(modulus.data(), modulus.size());
+
+    constexpr std::size_t RSA_EXPONENT_POS = 0xB4E0;
+    file.Seek(RSA_EXPONENT_POS, SEEK_SET);
+    std::vector<u8> exponent;
+    exponent.resize(256);
+    file.ReadArray(exponent.data(), exponent.size());
+
+    rsa_slots[0] = RsaSlot(exponent, modulus);
+    // TODO(B3N30): Initalize the other slots. But since they aren't used at all, we can skip them
+    // for now
+}
+
+RsaSlot GetSlot(std::size_t slot_id) {
+    if (slot_id >= rsa_slots.size())
+        return RsaSlot{};
+    return rsa_slots[slot_id];
+}
+
+std::vector<u8> CreateASN1Message(const std::vector<u8>& data) {
+    static constexpr auto asn1_header =
+        "0001FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
+        "FFFFFFFFFFFFFFFFFFFFFFFF003031300D060960864801650304020105000420";
+    std::vector<u8> message = HexToBytes(asn1_header);
+    CryptoPP::SHA256 sha;
+    std::array<u8, CryptoPP::SHA256::DIGESTSIZE> hash;
+    sha.CalculateDigest(hash.data(), data.data(), data.size());
+    std::copy(hash.begin(), hash.end(), std::back_inserter(message));
+    return message;
+}
+
+} // namespace HW::RSA