change around a few messages

3dsconv.py

@@ -15,13 +15,14 @@
 import sys
 import zlib
 
+# check for PyCrypto, which is used for zerokey support
 pycrypto_found = False
 try:
     from Crypto.Cipher import AES
     from Crypto.Util import Counter
     pycrypto_found = True
 except ImportError:
-    pass
+    pass  # this is handled later
 
 # default directories (relative to current dir unless you use absolute paths)
 # leave as "" for current working directory
@@ -54,6 +55,7 @@
     \"<TITLEID>.Main.exheader.xorpad\"
   XORpads should be in {} or the directory specified by --xorpads=<dir>
   XORpads are generated by using ncchinfo.bin with Decrypt9 on a 3DS system
+- zerokey encryption is supported with PyCrypto
 - encrypted and decrypted roms can be converted at the same time""".format(
     version,
     "current directory" if xorpad_directory == "" else "'{}'".format(xorpad_directory),
@@ -64,6 +66,7 @@
 # includes certificate chain, ticket (blank titlekey and title id), and tmd signature + blank header (blank title id)
 #    + blank content info records
 # compressed using zlib then encoded with base64
+# I should find a better way to store this... this is so ugly
 ciainfo = """eJztlWlQk0kagAmGOE4IIglyn2KMSIhAmKiggCByDTcIBBGJQDgikUMODXI6EUVAOcONJgoEUKIc
 K6ighCCHYDhEjsWAQLgSBWFUjnEWf03V7pSwNfNj9+l6u7q66u1+q/vp7xMACGwhGhzgPaov9M0k
 9QM0CbKpziYW5KLLMim3xJwiJkQWd0U2iYhqDh4cmqSk35107vPNpE2M+gqvaqvdvSkUg16L1WvV
@@ -225,8 +228,8 @@ def showprogress(val, maxval):
         decrypted = int(binascii.hexlify(romf.read(1))) & 0x04
         zerokey_enc = int(binascii.hexlify(romf.read(1))) & 0x01
         print("- processing: {} ({})".format(
-            rom[1], "decrypted" if decrypted else ("zerokey" if zerokey_enc else "encrypted"))
-        )
+            rom[1], "decrypted" if decrypted else ("zerokey" if zerokey_enc else "encrypted")
+        ))
         if noconvert:
             print("- not converting {} ({}) because --noconvert was used".format(
                 rom[1], "decrypted" if decrypted else "encrypted"
@@ -252,14 +255,13 @@ def showprogress(val, maxval):
         exh = romf.read(0x400)
         xor = ""
         if not decrypted:
-            print_v("- decrypting ExHeader")
             if zerokey_enc:
-                print_v("- using zerokey")
+                print_v("- decrypting ExHeader, using zerokey")
                 ctr = Counter.new(128, initial_value=long(tid + "0100000000000000", 16))
                 ctrmode = AES.new(zerokey, AES.MODE_CTR, counter=ctr)
                 exh = ctrmode.decrypt(exh)
             else:
-                print_v("- using XORpad")
+                print_v("- decrypting ExHeader, using XORpad")
                 with open(xorpad, "rb") as xorfile:
                     xor = xorfile.read(0x400)
                 xored = ""
@@ -308,22 +310,19 @@ def showprogress(val, maxval):
         x |= 2
         print_v("  shifted:  {}".format(hex(x)))
         exh_list[0xD:0xE] = chr(x)
-        # there really has to be a better way to do this...
-        # savesize = str(int(binascii.hexlify(exh[0x1C0:0x1C8][::-1]), 16) / 1024)
         exh = "".join(exh_list)
         savesize = exh[0x1C0:0x1C4]
         new_exh_hash = hashlib.sha256("".join(exh)).digest()
 
         if not decrypted:
-            print_v("- re-encrypting ExHeader")
             if zerokey_enc:
-                print_v("- using zerokey")
+                print_v("- re-encrypting ExHeader, using zerokey")
                 ctr = Counter.new(128, initial_value=long(tid + "0100000000000000", 16))
                 ctrmode = AES.new(zerokey, AES.MODE_CTR, counter=ctr)
                 exh = ctrmode.encrypt(exh)
                 pass
             else:
-                print_v("- using XORpad")
+                print_v("- re-encrypting ExHeader, using XORpad")
                 xored = ""
                 for byte_f, byte_x in zip(exh_list, xor):
                     xored += chr(ord(byte_f) ^ ord(byte_x))

README.md

@@ -1,7 +1,7 @@
 # 3dsconv
 `3dsconv.py` is a Python 2.7 script that converts Nintendo 3DS CTR Cart Image files (CCI, ".cci", ".3ds") to the CTR Importable Archive format (CIA).
 
-3dsconv can detect if a CCI is decrypted or encrypted. Decrypted is preferred and does not require any extra files. Encrypted requires Extended Header (ExHeader) XORpads, with the filename `<TITLEID>.Main.exheader.xorpad`.
+3dsconv can detect if a CCI is decrypted or encrypted, or zerokey-encrypted. Decrypted is preferred and does not require any extra files. Encrypted requires Extended Header (ExHeader) XORpads, with the filename `<TITLEID>.Main.exheader.xorpad`. Zerokey encryption works only if [PyCrypto](https://www.dlitz.net/software/pycrypto/) is installed (can be installed with pip).
 
 This does not work with Python 3.