Derive EVP key

Category: KDF

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

Input / output: string → string

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

What it does

This operation performs a password-based key derivation function (PBKDF) used extensively in OpenSSL. In many applications of cryptography, user security is ultimately dependent on a password, and because a password usually can’t be used directly as a cryptographic key, some processing is required. A salt provides a large set of keys for any given password, and an iteration count increases the cost of producing keys from a password, thereby also increasing the difficulty of attack. If you leave the salt argument empty, a random salt will be generated.

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`	Passphrase	`toggleString`	`{'string': '', 'option': 'UTF8'}`	`''`
`1`	Key size	`number`	`128`	A Python integer or floating-point value
`2`	Iterations	`number`	`1`	A Python integer or floating-point value
`3`	Hashing function	`option`	`'MD5'`	`'SHA1'`, `'SHA256'`, `'SHA384'`, `'SHA512'`, `'MD5'`
`4`	Salt	`toggleString`	`{'string': '', 'option': 'Hex'}`	`''`

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': 'UTF8'}, 128, 1, 'MD5', {'string': '', 'option': 'Hex'}]
result = bake(input_value, [{"op": 'Derive EVP key', "args": args}])
print(result)

Pipeline example

from pychef import Pipeline

args = [{'string': '', 'option': 'UTF8'}, 128, 1, 'MD5', {'string': '', 'option': 'Hex'}]
transform = Pipeline().then('Derive EVP key', *args)
result = transform("example")

Dedicated operation module

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

from pychef.operations.by_operation.derive_evp_key import run

result = run("example", tuple([{'string': '', 'option': 'UTF8'}, 128, 1, 'MD5', {'string': '', 'option': 'Hex'}]))

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

Run this operation using its shared internal implementation.

Parameters:

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

Return type:

str | bytes