XTEA Decrypt

Category: Ciphers

Status: Registered and callable in the CyberChef 11.3.0 compatibility inventory.

Input / output: string → string

Background: https://wikipedia.org/wiki/XTEA

What it does

XTEA (eXtended Tiny Encryption Algorithm) is a block cipher designed by David Wheeler and Roger Needham in 1997 as a successor to TEA, correcting several weaknesses identified in the original algorithm. It operates on 64-bit blocks using a 128-bit key with an improved key schedule that uses sum-dependent key word selection to resist related-key attacks. XTEA retains the simplicity and compact implementation of TEA whilst providing significantly improved security. It is frequently encountered in malware analysis and CTF challenges due to its straightforward implementation. Key: Must be exactly 16 bytes (128 bits). IV: The Initialisation Vector should be 8 bytes (64 bits). If not entered, it will default to null bytes. Rounds: The recommended number of rounds is 32 (default). The reference implementation by Wheeler & Needham accepts a configurable round count. Padding: In CBC and ECB mode, the PKCS#5 padding scheme is used.

Note

Status here means the operation name is implemented and callable. It does not by itself promise byte-for-byte parity for every upstream option. See Compatibility and current status for the verified scope and known boundaries.

Arguments and options

Arguments are positional. Keep their order when using bake() or Pipeline.then().

Index	Name	UI type	PyChef default	Accepted values / format
`0`	Key	`toggleString`	`{'string': '', 'option': 'Hex'}`	`''`
`1`	IV	`toggleString`	`{'string': '', 'option': 'Hex'}`	`''`
`2`	Mode	`option`	`'CBC'`	`'CBC'`, `'CFB'`, `'OFB'`, `'CTR'`, `'ECB'`
`3`	Input	`option`	`'Raw'`	`'Hex'`, `'Raw'`
`4`	Output	`option`	`'Hex'`	`'Raw'`, `'Hex'`
`5`	Padding	`option`	`'PKCS5'`	`'PKCS5'`, `'NO'`, `'ZERO'`, `'RANDOM'`, `'BIT'`
`6`	Rounds	`number`	`32`	A Python integer or floating-point value

Recipe template

Important

This is a call template built from the documented defaults. Replace placeholder values such as empty keys, paths, patterns, or lookup data before running it.

from pychef import bake

input_value = "example"
args = [{'string': '', 'option': 'Hex'}, {'string': '', 'option': 'Hex'}, 'CBC', 'Raw', 'Hex', 'PKCS5', 32]
result = bake(input_value, [{"op": 'XTEA Decrypt', "args": args}])
print(result)

Pipeline example

from pychef import Pipeline

args = [{'string': '', 'option': 'Hex'}, {'string': '', 'option': 'Hex'}, 'CBC', 'Raw', 'Hex', 'PKCS5', 32]
transform = Pipeline().then('XTEA Decrypt', *args)
result = transform("example")

Direct call

pychef.ops.run_operation runs any registered operation as a plain function, under the active ExecutionPolicy (safe defaults, no network):

from pychef.ops import run_operation

args = [{'string': '', 'option': 'Hex'}, {'string': '', 'option': 'Hex'}, 'CBC', 'Raw', 'Hex', 'PKCS5', 32]
result = run_operation('XTEA Decrypt', "example", args=args)

Common operations also have typed helpers in Direct operations.

Low-level operation module

Warning

The module below is an internal implementation detail. It applies no execution policy, resource limits, or error sanitization; prefer bake(), Pipeline, or pychef.ops for application code.

The registered entry point lives in pychef.operations.by_operation.xtea_decrypt. Direct calls receive the input value and a positional argument tuple:

from pychef.operations.by_operation.xtea_decrypt import run

result = run("example", tuple([{'string': '', 'option': 'Hex'}, {'string': '', 'option': 'Hex'}, 'CBC', 'Raw', 'Hex', 'PKCS5', 32]))

pychef.operations.by_operation.xtea_decrypt.run(value, args)

Run this operation using its shared internal implementation.

Parameters:

value (str | bytes)
args (Sequence[Any])

Return type:

str | bytes