From 551a48149f9c0ee4600beef822cbc6c41062597b Mon Sep 17 00:00:00 2001
From: d0k3 <tore.anon@gmail.com>
Date: Mon, 21 Aug 2017 19:56:30 +0200
Subject: [PATCH] Scripting: add fixcmac command

fixes #175
check HelloScript.gm9 for how it's done
---
 HelloScript.gm9           |  6 ++++++
 source/filesys/fsscript.c |  9 ++++++++-
 source/nand/nandcmac.c    | 40 +++++++++++++++++++++++++++++++++++++--
 source/nand/nandcmac.h    |  1 +
 4 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/HelloScript.gm9 b/HelloScript.gm9
index ff4fd6b..0e538e1 100644
--- a/HelloScript.gm9
+++ b/HelloScript.gm9
@@ -128,6 +128,12 @@ set ERRORMSG "SHA check failed (this was expected)"
 sha -o $[RENPATH] $[TESTPATH].sha
 set ERRORMSG ""
 
+# 'fixcmac' COMMAND
+# Use this to fix the CMACs for a file or a whole folder (recursively)
+# This will count as success if a file does not contain a CMAC
+# More info on CMACs: http://3dbrew.org/wiki/Savegames#AES_CMAC_header
+# fixcmac 1:/data
+
 # 'verify' COMMAND
 # Certain file formats (NAND, NCCH, NCSD, CIA, FIRM, ...) can also be verified. Use 'verify' to do so.
 # verify -o s:/firm0.bin # As drive letters are case sensitive, this would fail
diff --git a/source/filesys/fsscript.c b/source/filesys/fsscript.c
index f50eb24..a0bf653 100644
--- a/source/filesys/fsscript.c
+++ b/source/filesys/fsscript.c
@@ -2,6 +2,7 @@
 #include "fsutil.h"
 #include "fsinit.h"
 #include "fsperm.h"
+#include "nandcmac.h"
 #include "nandutil.h"
 #include "gameutil.h"
 #include "keydbutil.h"
@@ -46,6 +47,7 @@ typedef enum {
     CMD_ID_DECRYPT,
     CMD_ID_ENCRYPT,
     CMD_ID_BUILDCIA,
+    CMD_ID_BOOT,
     CMD_ID_REBOOT,
     CMD_ID_POWEROFF
 } cmd_id;
@@ -78,11 +80,12 @@ Gm9ScriptCmd cmd_list[] = {
     { CMD_ID_FIND    , "find"    , 2, 0 },
     { CMD_ID_FINDNOT , "findnot" , 2, 0 },
     { CMD_ID_SHA     , "sha"     , 2, 0 },
-    // { CMD_ID_FIXCMAC , "fixcmac" , 1, 0 }, // not supported yet
+    { CMD_ID_FIXCMAC , "fixcmac" , 1, 0 },
     { CMD_ID_VERIFY  , "verify"  , 1, 0 },
     { CMD_ID_DECRYPT , "decrypt" , 1, 0 },
     { CMD_ID_ENCRYPT , "encrypt" , 1, 0 },
     { CMD_ID_BUILDCIA, "buildcia", 1, _FLG('l') },
+    // { CMD_ID_BOOT    , "boot"    , 1, 0 },  // not supported yet
     { CMD_ID_REBOOT  , "reboot"  , 0, 0 },
     { CMD_ID_POWEROFF, "poweroff", 0, 0 }
 };    
@@ -445,6 +448,10 @@ bool run_cmd(cmd_id id, u32 flags, char** argv, char* err_str) {
             ret = (memcmp(sha256_fil, sha256_cmp, 0x20) == 0);
             if (err_str) snprintf(err_str, _ERR_STR_LEN, "sha does not match");
         }
+    } else if (id == CMD_ID_FIXCMAC) {
+        ShowString("Fixing CMACs...");
+        ret = (RecursiveFixFileCmac(argv[0]) == 0);
+        if (err_str) snprintf(err_str, _ERR_STR_LEN, "fixcmac failed");
     } else if (id == CMD_ID_VERIFY) {
         u32 filetype = IdentifyFileType(argv[0]);
         if (filetype & IMG_NAND) ret = (ValidateNandDump(argv[0]) == 0);
diff --git a/source/nand/nandcmac.c b/source/nand/nandcmac.c
index 7197c89..119ee82 100644
--- a/source/nand/nandcmac.c
+++ b/source/nand/nandcmac.c
@@ -6,14 +6,14 @@
 #include "vff.h"
 
 // CMAC types, see:
-// https://www.3dbrew.org/wiki/Savegames#AES_CMAC_header
+// https://3dbrew.org/wiki/Savegames#AES_CMAC_header
 // https://3dbrew.org/wiki/Nand/private/movable.sed
 // https://3dbrew.org/wiki/3DS_Virtual_Console#NAND_Savegame
 #define CMAC_EXTDATA_SD     1
 #define CMAC_EXTDATA_SYS    2
 #define CMAC_SAVEDATA_SYS   3
 #define CMAC_SAVE_GAMECARD  4
-#define CMAC_SAVEGAME       5 // this is not calclated into a CMAC
+#define CMAC_SAVEGAME       5 // this is not calculated into a CMAC
 #define CMAC_SAVEDATA_SD    6
 #define CMAC_TITLEDB_SYS    7
 #define CMAC_TITLEDB_SD     8
@@ -233,3 +233,39 @@ u32 FixFileCmac(const char* path) {
     u8 ccmac[16];
     return ((CalculateFileCmac(path, ccmac) == 0) && (WriteFileCmac(path, ccmac) == 0)) ? 0 : 1;
 }
+
+u32 RecursiveFixFileCmacWorker(char* path) {
+    FILINFO fno;
+    
+    if (fvx_stat(path, &fno) != FR_OK) return 1; // path does not exist
+    if (fno.fattrib & AM_DIR) { // process folder contents
+        DIR pdir;
+        char* fname = path + strnlen(path, 255);
+        if (fvx_opendir(&pdir, path) != FR_OK) return 1;
+        *(fname++) = '/';
+        
+        while (f_readdir(&pdir, &fno) == FR_OK) {
+            if ((strncmp(fno.fname, ".", 2) == 0) || (strncmp(fno.fname, "..", 3) == 0))
+                continue; // filter out virtual entries
+            strncpy(fname, fno.fname, path + 255 - fname);
+            if (fno.fname[0] == 0) {
+                break;
+            } else if (fno.fattrib & AM_DIR) { // directory, recurse through it
+                if (RecursiveFixFileCmacWorker(path) != 0) return 1;
+            } else if (CheckCmacPath(path) == 0) { // file, try to fix the CMAC
+                if (FixFileCmac(path) != 0) return 1;
+            }
+        }
+        f_closedir(&pdir);
+        *(--fname) = '\0';
+    } else if (CheckCmacPath(path) == 0)
+        return FixFileCmac(path);
+    
+    return 0;
+}
+
+u32 RecursiveFixFileCmac(const char* path) {
+    char lpath[256] = { 0 };
+    strncpy(lpath, path, 255);
+    return RecursiveFixFileCmacWorker(lpath);
+}
diff --git a/source/nand/nandcmac.h b/source/nand/nandcmac.h
index 9a92cae..bf83c00 100644
--- a/source/nand/nandcmac.h
+++ b/source/nand/nandcmac.h
@@ -8,3 +8,4 @@ u32 WriteFileCmac(const char* path, u8* cmac);
 u32 CalculateFileCmac(const char* path, u8* cmac);
 u32 CheckFileCmac(const char* path);
 u32 FixFileCmac(const char* path);
+u32 RecursiveFixFileCmac(const char* path);