18
votes
How are Apple App Store Apps encrypted?
When you download an app from the App Store, Apple injects a special 4196 byte long header into the signed binary encrypted with the public key associated with your iTunes account. This public/...
- 615
9
votes
Question about Keeloq - A car remote control standard
To create a full duplicate, able to generate valid transmission packets you'll need the following information:
Serial Number
Button press mapping
32 bit of KeeLoq encrypted data
See attached Figure ...
- 11.8k
9
votes
Accepted
McDonald's receipt codes
As suggested in a comment, the final character is indeed a check digit. It appears to be calculated using the Luhn algorithm with 25 as the base instead of 10.
Using the code in photo as an example:
...
- 363
8
votes
Reverse Engineering a Firmware. Someone can help me?
Finding: NGA_FW_CURRENT.BIN is a compressed Videx microchip firmware image file.
Preliminary Remarks
There is conflicting background information given in the comments about the file alleged to be ...
- 7,236
7
votes
How to decrypt encrypted script files for a game?
There are two noteworthy communities dedicated to reversing file formats with video games: XeNTaX and ZenHAX
Both of them have their own respective applications used for creating scripts that unpack ...
- 2,254
7
votes
Accepted
How to decompile an exe file?
I have been wondering, if every program is based on machine code, can we not decompile a program until it hits machine code and make it up to real programming languages?
This question is based on a ...
- 7,236
7
votes
Finding AES Key in binary using Ghidra and FindCrypt
FindCrypt is not supposed to find your key, it's supposed to find fixed, known constants associated with well-known cryptographic algorithms. You can see the byte patterns it's looking for in its ...
- 9,218
6
votes
Accepted
Decrypt the config file of ZTE F660 v9
Download script and config file
Install zcu from https://github.com/mkst/zte-config-utility
KEY = SERIAL + MAC: CF28772Bf438d406f608 from paramtag
IV = DefAESCBCIV: ZTE%FN$GponNJ025 from /etc/...
- 311
6
votes
i need software to decode this subtitle xml file, anyone know what it encodes with?
It's AES encrypted, but fortunately it's pretty trivial to see what's going on in the JavaScript file responsible for decoding (https://www.gohitv.com/series/js/hiplayer.min.js) by using browser ...
- 363
5
votes
Animal Crossing: Pocket Camp .zdat File
The file does not appear to be obfuscated or encrypted in any way. The header appears to be trivial. I have included a description of the header for the .zdata you posted. The .unity3d files contained ...
- 326
5
votes
Accepted
Unknown game file decompress
it seems to be compressed in some way because you can read some plain text there
This statement is contradictory. If the binary were compressed or encrypted in its entirety there would not be any ...
- 7,236
5
votes
Accepted
Stuck on XOR decryption of firmware
Well thanks to @IgorSkochinsky's suggestion, I found a disassembler for the Blackfin architecture in the pf0camino/cross-bfin-elf Docker image. Being in Docker meant it was easy to run and I didn't ...
- 343
4
votes
Extract decrypted Assembly-CSharp.dll from APK via IDA
I think the solution is a very simple one, with one small tweak.
To decrypt the file,
XOR the encrypted data with the bytes 0xFCC6DC7FDCC7DFE0 and you will get the unencrypted file.
You can see this ...
- 501
4
votes
Unknown CRC calculation
MED17 functional description docs will help with overview of the EEP handler, but not the checksum routine.
Usually it is best to go through the front door with coding tools rather than try to change ...
- 133
4
votes
Decrypt / Decode / Decompress Proprietary File
I took a look at the empty template file that you provided. The file has a very high entropy which indicates that it's probably encrypted and not compressed.
The header in the file could be a lot of ...
- 171
4
votes
how to find the encryption algorithm?
First, I have to say several things don't quite add up in the decompilation, and I often find it easier to understand disassembly than decompilation
Let's start with the function doing most of the ...
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4
votes
Accepted
how to find the encryption algorithm?
All the credit for this this answer should go to the @NirIzr and @Avery3R.
Here is a python script that implements the xoring mentioned by these kind people:
import urllib
import binascii
data = "%...
- 8,538
4
votes
Decrypting SQLite Database with key
There exists an official encryption addon for SQLite but from your description it sounds more like the data is simply stored encrypted in the blobs and the application decrypts it internally before ...
- 36.9k
4
votes
Accepted
Reverse engineering checksum - LG 485 a/c protocol
did not check the second set
but your first set appears to be xorred by 0x55
0x55 ^ 0x18 == 0x4d (8 bit checksum )
edit
ok my guess was right here is a python script that prints the chksum
...
- 16.7k
4
votes
Accepted
Help reverse decrypt function (decode -> encode)
For
a = b ^ c
Since the XOR operation is trivial to reverse when any 2 values in a, b, c are known, this will only require you to just reverse the order in which operations were done. I had to do ...
- 2,739
4
votes
Accepted
Intercept zip decryption key or files from an application
I'm writing this answer under the assumption the OP is within his legal rights to share the binaries.
First of, I read up on password protected zip files. Apparently that is not part of the ZIP ...
- 1,391
4
votes
Accepted
Reverse Engineering Temperatures (RS485 Bus)
I would guess that this is raw (unencoded) data and every row is consisted of two 16 bit integers stored in little-endian order. This means that
temperature = (float)(b[3] << 8 + b[2]) / 10;
...
- 156
4
votes
Accepted
Decoding Hex Data
The data are floating point encoded on 32 bits Little_endian
byte 0 to 3: 00 00 00 00 = 0 channel number
byte 4 to 7: 1f 85 a3 41 = 0x41a3851f = 20.4400005341
etc ..
https://www.h-schmidt.net/...
- 416
3
votes
Unknown CRC calculation
A9 68 01 00 FF 7F 00 80 FF 7F 00 80 FF 7F 00 80
FF 7F 00 80 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
...
3
votes
Decrypting assets (json/png/lua)
There are a few things you can still try, like running signsrch over the binary to see if it has any encryption algorithm signatures.
Also, gzipping these files increases their size:
gbl@roran:~/...
- 13k
3
votes
Reverse engineer CAN-Bus checksum
As can be demonstrated by this page:
CRC width: CRC-8
CRC parametrization: Predefined, CRC8_SAE_J1850 (Polynomial: 0x1d, Initial value: 0xff, Final xor: 0xff)
CRC Input Data: Bytes, D1-D7
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3
votes
Accepted
Difficulty decrypting LCG string
I found this paper that shed some light onto what's happening:
https://www.blueliv.com/downloads/technical-report-vawtrak-v2.pdf
So I took the PHPSESSIONID from your screenshot and wrote this script:...
- 1,391
3
votes
Accepted
how can i Encrypt a decrypted zte zxhn h108n V2.5 config file?
You can use the zcu module to do this.
python examples/encode.py config.bin.xml out.bin --key 'GrWM2Hz<vz&f^5' --signature 'ZXHN H108N V2.5'
Full disclosure: I wrote the zcu module. It's ...
- 266
3
votes
Accepted
Recognize a decryption algorithm
The function parses the PE header to locate the IMAGE_EXPORT_DIRECTORY which has the structure
NumberOfNames contains the number of symbols exported by this PE and is located at an offset of 0x18.
...
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3
votes
Need help with ZTE router config.bin file decryption and encryption
You can use the zcu module (written by Mark Streetster) to decrypt/encrypt your config.bin file.
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