msgdata.c through DecryptMessageDirect

1 files changed, 59 insertions, 0 deletions

diff --git a/arm9/src/msgdata.c b/arm9/src/msgdata.c
new file mode 100644
index 00000000..b3a1c027
--- /dev/null
+++ b/arm9/src/msgdata.c
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "filesystem.h"
+#include "msg_data.h"
+#include "heap.h"
+
+#pragma thumb on
+
+void * LoadSingleElementFromNarc(NarcId narc_id, s32 file_id, u32 heap_id);
+void FreeMsgDataRawData(void * data);
+void CopyEncryptedMessage16(u16 * dest, const u16 * src, struct UnkStruct_200A394_4 * param);
+void DecryptMessageDirect(struct UnkStruct_200A394 * r3, u32 r5, u16 * r4);
+
+void * LoadSingleElementFromNarc(NarcId narc_id, s32 file_id, u32 heap_id)
+{
+    return AllocAndReadWholeNarcMemberByIdPair(narc_id, file_id, heap_id);
+}
+
+void FreeMsgDataRawData(void * data)
+{
+    FreeToHeap(data);
+}
+
+inline static void Decrypt1(struct UnkStruct_200A394_4 * arg0, u32 arg1, u32 seed)
+{
+    seed = seed * 765 * (arg1 + 1) & 0xffff;
+    seed |= seed << 16;
+    arg0->unk0 ^= seed;
+    arg0->unk4 ^= seed;
+}
+
+inline static void Decrypt2(u16 * arg0, u32 count, u32 arg2)
+{
+    u16 seed = (arg2 + 1) * 596947;
+
+    while (count-- > 0)
+    {
+        *arg0 ^= seed;
+        seed += 18749;
+        arg0++;
+    }
+}
+
+void DecryptMessageDirect(struct UnkStruct_200A394 * r3, u32 r5, u16 * r4)
+{
+    struct UnkStruct_200A394_4 sp0;
+
+    if (r5 < r3->unk0)
+    {
+        sp0 = r3->unk4[r5];
+        Decrypt1(&sp0, r5, r3->unk2);
+
+        CopyEncryptedMessage16(r4, (const u16 *)((u8 *)r3 + sp0.unk0), &sp0);
+        Decrypt2(r4, sp0.unk4, r5);
+    }
+    else
+    {
+        GF_ASSERT(0);
+    }
+}