peterpawn / decoder Goto Github PK

• add german (HTML) descriptions, how-to use the various applets
• add an english excerpt (replaces README.md from root directory) for non-german readers/users

closes #11

• read into memory buffers with predefined or specified size
• consolidate input buffer (unconditionally), makes handling easier and less error-prone
• carry out all processing with this one memory buffer, optional copy to a new one, if needed
• write all output data at once, after processing completed and not while processing takes place

• extra applet and an additional option for 'decode_export'
• consider the reverse processing (build export file - with customizable header lines - from single files) as another applet

• add another applet, which is able to read the needed parameters from a HTML form and executes 'decode_export' for an uploaded file
• may be used with any CGI-enabled HTTP server, but without any additional code (beside the HTML form), to decrypt an exported settings file
• for users, who haven't access to an own system, which is supported by this project

Hello, to avoid a compilation error of: multiple definitions... please declare
extern void (*usageScreen)(void);
in functions.h
Regards

fill the subfunctions with some text to display

fix buffer handling in decode_export - some values aren't decrypted, if they don't fit into a single buffer

• this may only make sense for the C implementation, because dissection of an export file with shell commands is time-consuming again and the re-composition isn't really faster

• MIPSR32 (34kc) for VR9 based devices
• ARMv7 for RasPi
• ARMv6 for Puma5/Puma6
• x86 (32 bit) for Linux systems and the ATOM core of Puma6 devices
• x86 (64 bit) for Linux systems and the "Windows bash" on Win64 systems

When executing make, I received the error message 'gpg: error reading key: No public key' from download.sh.

After digging around, I found that the keyserver hkp://keys.gnupg.net:11371 is not responding.
This server does not seem to exist anymore!

Workaround:
Modify the file src/nettle/download.sh as follows:
Replace
keyServer=hkp://keys.gnupg.net:11371
with (e.g.)
keyServer=keyserver.ubuntu.com
Or use some other keyserver

Then make runs without errors.

Hi,

[I apologize if this is not the right place to post this issue]

I am trying to decode a backup exported from my FritzBox with the following command:

./decoder.x86_64 decode_export -a env < FRITZ.Box\ 7272\ \(UI\)\ 120.06.88_11.03.22_1401.export

whereenv is a file with the following content:

SerialNumber    E50448830126160
maca    5C:49:79:57:47:5A
wlan_key        25083886372223913969

I got error

decode_export: The device property 'SerialNumber' is not set.

Any hint what I am missing please? I use the pre-compiled binary from the latest release.

• optional usage of libnettle instead of libssl libcrypto from OpenSSL

• at least 'decode_export' should be runnable from any platform with ANSI C support (C99) without too much changes

the decoder cant read a export file from a FB7530 164.07.21. Why? And where i can specify the password for the export file?
when i run "./decoder.x86_64 decode_secrets ../../../../Downloads/FRITZ.Box\ 7530\ 164.07.21_13.05.22_1650.export" , reports the script:
decode_secrets: Error opening environment file '/proc/sys/urlader/environment'.

In my opinion "decoder" is too generic, see for example https://gitlab.gnome.org/World/decoder.
I propose to rename the project so that the name doesn't collide with anything else. Maybe something like fritz-decoder or fritz-config-tools?

The decoder seg faults when doing decode_secret
Program received signal SIGSEGV, Segmentation fault.
0x000000000041625f in _nettle_aes_set_key (nr=14, nk=8, subkeys=0x0, key=0x6efc50 "\235\262\207\260\204W\274rX\331%\254\304\312", <incomplete sequence \332>) at aes-set-key-internal.c:60 60 subkeys[i] = LE_READ_UINT32(key + i*4); (gdb) bt #0 0x000000000041625f in _nettle_aes_set_key (nr=14, nk=8, subkeys=0x0, key=0x6efc50 "\235\262\207\260\204W\274rX\331%\254\304\312", <incomplete sequence \332>)
at aes-set-key-internal.c:60
#1 0x0000000000416179 in nettle_aes256_set_encrypt_key (ctx=0x0, key=0x6efc50 "\235\262\207\260\204W\274rX\331%\254\304\312", <incomplete sequence \332>) at aes256-set-encrypt-key.c:43 #2 0x0000000000414a8e in nettle_aes256_set_decrypt_key (ctx=0x0, key=0x6efc50 "\235\262\207\260\204W\274rX\331%\254\304\312", <incomplete sequence \332>)
at aes256-set-decrypt-key.c:50
#3 0x0000000000405189 in CipherInit (ctx=0x0, mode=CipherTypeValue, key=0x6efc50 "\235\262\207\260\204W\274rX\331%\254\304\312", <incomplete sequence \332>, iv=0x6efb90 "\370\230ϲP\352\255#\264\070\070)V\354hi\311\350\223o\221\070\rZ\206\253\231\061\220X\352'\032\n\177\017\224\030XqC5Va\aɃJI\247Ȁ#\b\245\252\025\003\203X\253\222p", padding=false) at crypto_nettle.c:89
#4 0x000000000040c830 in decsngl_entry (argc=5, argv=0x7fffffffdd58, argo=1, entry=0x6e8ce0 <__decsngl_command>) at decsngl.c:218
#5 0x000000000041471d in main (argc=5, argv=0x7fffffffdd58) at decoder.c:140

• call AVM's 'ar7cfgctl' to extract structured data from config files and decrypt any encrypted value returned from 'ar7cfgctl' while writing to STDOUT

The second entry in header (Password2) leads to a decryption error and as a result, the output data contains the original and encrypted values, while the "--verbose" option displays correct decryption for all entries following the header.

Removing the second entry with an editor, leads to a normal processing for the whole file.

see Freetz-NG/freetz-ng#214 (reply in thread)

• it's an outstanding ToDo
• probably add this only to the C solution, because it takes too much time using shell commands only; the hex2bin (and vs.) conversion is very expensive

• at least the (XML) file "umts.cfg" contains encrypted data (in the PIN field) and will be stored as hexadecimal data in an export file
• currently the scanner will not detect such entries while looking for encrypted data, because it doesn't know anything about the data to be scanned and can't convert a "BINFILE" to the binary representation (which means 'XML' for this one)
• usually I ignore all files from "AVM home automation" - maybe there are additional entries hidden

no further description - wrong options may result in a segfault or in absolutely wrong messages