[NCCH/NCSD] Pain

include/loader/ncch.hpp

@@ -1,4 +1,5 @@
 #pragma once
+#include <array>
 #include "helpers.hpp"
 
 struct NCCH {
@@ -7,13 +8,20 @@ struct NCCH {
     bool compressExeFS = false;
     bool mountRomFS = false;
     bool encrypted = false;
+    bool fixedCryptoKey = false;
 
     static constexpr u64 mediaUnit = 0x200;
     u64 size = 0; // Size of NCCH converted to bytes
     u32 stackSize = 0;
     u32 bssSize = 0;
+    u32 exheaderSize = 0;
 
     // Header: 0x200 + 0x800 byte NCCH header + exheadr
     // Returns true on success, false on failure
     bool loadFromHeader(u8* header);
+    bool hasExtendedHeader() { return exheaderSize != 0; }
+
+private:
+    std::array<u8, 16> primaryKey = {}; // For exheader, ExeFS header and icons
+    std::array<u8, 16> secondaryKey = {}; // For RomFS and some files in ExeFS
 };

src/core/loader/ncch.cpp

@@ -3,23 +3,44 @@
 #include "memory.hpp"
 
 bool NCCH::loadFromHeader(u8* header) {
-    const u8* exheader = &header[0x200]; // Extended NCCH header
-
     if (header[0x100] != 'N' || header[0x101] != 'C' || header[0x102] != 'C' || header[0x103] != 'H') {
         printf("Invalid header on NCCH\n");
         return false;
     }
 
     size = u64(*(u32*)&header[0x104]) * mediaUnit; // TODO: Maybe don't type pun because big endian will break
+    exheaderSize = *(u32*)&header[0x180];
+
+    const u64 programID = *(u64*)&header[0x118];
 
     // Read NCCH flags
     isNew3DS = header[0x188 + 4] == 2;
-    mountRomFS = (header[0x188 + 7] & 0x1) != 0x1;
+    fixedCryptoKey = (header[0x188 + 7] & 0x1) == 0x1;
+    mountRomFS = (header[0x188 + 7] & 0x2) != 0x2;
     encrypted = (header[0x188 + 7] & 0x4) != 0x4;
 
-    compressExeFS = (exheader[0xD] & 1) != 0;
-    stackSize = *(u32*)&exheader[0x1C];
-    bssSize = *(u32*)&exheader[0x3C];
+    bool encryptedExheader = encrypted;
+
+    if (fixedCryptoKey) {
+        Helpers::panic("Fixed crypto keys for NCCH");
+    }
+
+    if (exheaderSize != 0) {
+        const u8* exheader = &header[0x200]; // Extended NCCH header
+        const u64 jumpID = *(u64*)&exheader[0x1C0 + 0x8];
+
+        // TODO: How does this even work
+        if (u32(programID) == u32(jumpID) && encryptedExheader) {
+            printf("Exheader is supposedly ecrypted but not actually encrypted\n");
+            encryptedExheader = false;
+        } else if (encryptedExheader) {
+            Helpers::panic("Encrypted exheader");
+        }
+
+        compressExeFS = (exheader[0xD] & 1) != 0;
+        stackSize = *(u32*)&exheader[0x1C];
+        bssSize = *(u32*)&exheader[0x3C];
+    }
 
     printf("Stack size: %08X\nBSS size: %08X\n", stackSize, bssSize);
 

src/core/loader/ncsd.cpp

@@ -64,5 +64,10 @@ std::optional<NCSD> Memory::loadNCSD(const std::filesystem::path& path) {
         }
     }
 
+    if (!ncsd.partitions[0].ncch.hasExtendedHeader()) {
+        printf("NCSD's CXI doesn't have exheader?\n");
+        return std::nullopt;
+    }
+
     return ncsd;
 }