added romfs support

Author: Morten Delenk

ncch.py

@@ -22,6 +22,7 @@ def __init__(self, f,ip):
         self.cryptoSec3=self.flags[3]==0x0A
         self.cryptoSec4=self.flags[3]==0x0B
         self.cryptoFixkey=self.flags[7]&1
+        self.nocrypto=self.flags[7]&0x4
         self.keyY=header[:16]
         self.doExHeader()
     def addCtr(self,ctr,val):
@@ -44,6 +45,8 @@ def read(self,sectorno,sectors=1):
         f=self.f
         f.seek(sectorno*512)
         decdata=b''
+        if self.nocrypto:
+            return f.read(sectors*512)
         if sectorno == 0:
             #Sector is unencrypted
             data=f.read(512)

romfsfuse.py

@@ -0,0 +1,172 @@
+#!/usr/bin/env python3
+import logging
+from errno import ENOENT, EIO
+from stat import S_IFDIR, S_IFLNK, S_IFREG
+from sys import argv, exit
+from time import time
+import subprocess
+from fuse import FUSE, FuseOSError, Operations, LoggingMixIn
+import struct
+class romfsFile:
+    def __repr__(self):
+        if self.isdir:
+            s = "Directory '{}' with subdirs [".format(self.name)
+            for subdir in self.children:
+                s+=subdir.name+", "
+            s+="] and files ["
+            for fil in self.files:
+                s+=fil.name+", "
+            s+="]."
+            return s
+        return "File '{}' of size {} at {}".format(self.name,hex(self.length),hex(self.off))
+class RomFS(LoggingMixIn, Operations):
+    def traverse(self):
+        parent,sibling,child,ffile,namelen=struct.unpack("<IIIIxxxxI",self.f.read(0x18))
+        fi = romfsFile()
+        fi.isdir=True
+        fi.name=self.f.read(namelen)
+        fi.name=fi.name.decode("UTF-16")
+        if len(fi.name) != 0:
+            if fi.name[-1] == '\x00':
+                fi.name=fi.name[:-1]
+        fi.siblings=[]
+        if sibling != 0xFFFFFFFF:
+            self.f.seek(self.dirmetaOff+sibling)
+            siblin = self.traverse()
+            fi.siblings=[siblin]+siblin.siblings
+        fi.children=[]
+        if child != 0xFFFFFFFF:
+            self.f.seek(self.dirmetaOff+child)
+            chld = self.traverse()
+            fi.children=[chld]+chld.siblings
+        fi.files=[]
+        if ffile != 0xFFFFFFFF:
+            self.f.seek(self.filemetaOff+ffile)
+            fil = self.traverse_file()
+            fi.files=[fil]+fil.siblings
+        return fi
+    def traverse_file(self):
+        parent,sibling,dataoff,datalen,namelen=struct.unpack("<IIQQxxxxI",self.f.read(0x20))
+        fi = romfsFile()
+        fi.isdir=False
+        fi.name=self.f.read(namelen).decode("UTF-16")
+        if len(fi.name) != 0:
+            if fi.name[-1] == '\x00':
+                fi.name=fi.name[:-1]
+        fi.siblings=[]
+        if sibling != 0xFFFFFFFF:
+            self.f.seek(self.filemetaOff+sibling)
+            siblin = self.traverse_file()
+            fi.siblings=[siblin]+siblin.siblings
+        fi.off=dataoff
+        fi.length=datalen
+        return fi
+    def gentree(self,fi,path=""):
+        name=path+fi.name
+        root=False
+        if name=="":
+            root=True
+            name="/"
+        if fi.isdir:
+            name+="/"
+            self.files[name[:-1]]=dict(st_mode=(S_IFDIR | 0o555), st_ctime=self.now, st_mtime=self.now, st_atime=self.now, st_nlink=2)
+            if root:
+                name=name[:-1]
+            for subdir in fi.children:
+                self.gentree(subdir, name)
+            for fil in fi.files:
+                self.gentree(fil, name)
+            return
+        self.filelocs[name] = fi.off
+        self.files[name]=dict(st_mode=(S_IFREG | 0o555), st_ctime=self.now, st_mtime=self.now, st_atime=self.now, st_nlink=2, st_size=fi.length, st_blocks=(fi.length+511)//512)
+    def __init__(self,fname,mount):
+        def align(a,b):
+            if a%b:
+                return a-(a%b)+b
+            return a
+        self.f=open(fname,"rb")
+        print("Reading header")
+        self.header=self.f.read(0x5C)
+        masterhashsize=struct.unpack("<I",self.header[0x08:0x0C])[0]
+        hashblocksize=1<<struct.unpack("<I",self.header[0x4C:0x50])[0]
+        v=align(0x5C+masterhashsize,hashblocksize)
+        self.f.seek(v)
+        print("Reading l3 header")
+        self.level3h=self.f.read(0x28)
+        self.dirmetaOff,self.dirmetaSize,self.filemetaOff,self.filemetaSize,self.fileDataOff=struct.unpack("<IIxxxxxxxxIII",self.level3h[0xC:0x28])
+        self.dirmetaOff+=v
+        self.filemetaOff+=v
+        self.fileDataOff+=v
+        self.f.seek(self.dirmetaOff)
+        self.root=self.traverse()
+        self.filelocs={}
+        self.fd=1
+        self.now=time()
+        self.files={}
+        self.gentree(self.root)
+    def chmod(self, path, mode):
+        raise FuseOSError(EIO)
+    def chown(self, path, uid, gid):
+        raise FuseOSError(EIO)
+    def create(self, path, mode):
+        raise FuseOSError(EIO)
+    def getattr(self,path,fh=None):
+        if path not in self.files:
+            raise FuseOSError(ENOENT)
+        return self.files[path]
+    def getxattr(self,path,name,position=0):
+        return ''
+    def listxattr(self,path):
+        return []
+    def mkdir(self,path,mode):
+        raise FuseOSError(EIO)
+    def open(self,path,flags):
+        self.fd+=1
+        return self.fd
+    def read(self,path,size,offset,fh):
+        self.f.seek(self.filelocs[path]+offset+self.fileDataOff)
+        return self.f.read(size)
+    def readdir(self, path, fh):
+        print(path)
+        files=['.','..']
+        for fi in self.files.keys():
+            sp=fi.split("/")
+            if len(sp) != 2 or path != "/":
+                if '/'.join(sp[:-1]) != path:
+                    continue
+            if fi=="/":
+                continue
+            files.append(sp[-1])
+        return files
+    def readlink(self, path):
+        return self.data[path]
+    def removexattr(self, path, name):
+        raise FuseOSError(EIO)
+    def rename(self, old, new):
+        raise FuseOSError(EIO)
+    def rmdir(self, path):
+        raise FuseOSError(EIO)
+    def setxattr(self, path, name, value, options, position=0):
+        raise FuseOSError(EIO)
+    def statfs(self,path):
+        return dict(f_bsize=512, f_blocks=4096, f_bavail=0)
+    def symlink(self, target, source):
+        raise FuseOSError(EIO)
+    def truncate(self,path,length,fh=None):
+        raise FuseOSError(EIO)
+    def unlink(self,path):
+        raise FuseOSError(EIO)
+    def utimens(self,path,times=None):
+        raise FuseOSError(EIO)
+    def write(self,path,data,offset,fh):
+        raise FuseOSError(EIO)
+    def flush(self,path,fh):
+        pass
+    def release(self,path,fh):
+        pass
+
+if len(argv) != 3:
+    print("usage: {name} <ROMFS> <mountpoint>".format(name=argv[0]))
+    exit(1)
+logging.basicConfig(level=logging.WARNING)
+fuse = FUSE(RomFS(argv[1], argv[2]),argv[2], foreground=False)